It has been less than a year and a half since the St Jude and Canadian researchers came out simultaneously with publications on histone H3 mutations in pediatric glioblastoma and DIPG. These were the first ever reports on a "recurrent mutation in a regulatory histone in humans to case cancer and it seemed that those mutations may be drivers to alter the chromatinc architecture underlying the formation of pediatric GBMs and DIPGs. The H3 mutation specifically related to DIPGs seems to be K27M.
This seemed to generate a huge amount of interest in pediatric high grade glioma/DIPG research as this SNO/PBTF Pediatric Neuro-Oncology Basic and Translational Research Conference held in Fort Lauderdale this week had several abstracts on this exact subject. In fact 4 of the 11 abstracts in the brainstem glioma section included K27M in their title.
Functional Analysis of the H3.3-K27M Mutaton in DIPG
University of Toronto, Duke University, The Hospital for Sick Children
H3.3 K27M accelerates PDGR-induced brainstem gliomagenesis in vivo
Duke Univeristy and Laboratory of Chromatin Biology and Epigenetic (NY)
Targeting the histone H3.3-K27M mutation for the treatment of diffuse intrinsic pontine gliomas
UCSF and Georgetown
The type of histone H3-variant K27M mutation drives the agressiveness of Diffuse Intrinsic Pontine Gliomas
France and UK
In addition, another abstract lists that all the 20 previsously untreated DIPG specimens in their study had the K27M mutition. This abstract entitled "The genomic landscape of treatment naive DIPG biopsy samples" was a combined effort from Paris, France; Barcelona, Spain; London, UK and Vancouver, Canada.
It would seem that this K27M mutation is going to dominant upcoming discussions regarding DIPG. The Allis-Becher research alliance has already produced an elegant paper coming out electronically ahead of print the end of March in Science. This article found that the K27M point mutation is specific to the for the mistake of methionine for lysine at that location. No other amino acid mistake in production causes the same problems. These authors propose that this mutation inhibits a specific complex which promotes tumor formation. It is more complex than that but that is the general idea.
The potential of importance is varied when looking at these abstacts. This K27M mutation could be:
-"one of the first prognositic markers when judging results of prospective trials"
-"a target for novel intervention"
-and a mechanism for DIPG formation.
For those interested in DIPG research, I predict the K27M and other histone mutation research is going to be in the forefront in the near future.
Reference:
Brainstem Tumors, Radiaiton Therapy and Medulloblastoma (Platform Presentation Abstracts)
https://soc-neuro-onc.conference-services.net/programme.asp?conferenceID=3467&action=prog_list&session=26434
Inhibition of PRC2 Activity by a Gain of Function H3 Mutation Found in Pediatric Glioblastoma
http://www.ncbi.nlm.nih.gov/pubmed/23539183
Exceptional new Allis lab Science paper on exploding area of histone H3.3 in pedaitric brain cancer
http://www.ipscell.com/tag/h3-3-k27m/
Showing posts with label DIPG research. Show all posts
Showing posts with label DIPG research. Show all posts
Saturday, May 18, 2013
Thursday, May 9, 2013
Stanford's Big News- Anti CD47
Recently there has been quite a bit of press over Stanford's research on an anti-CD 47 drug because of a recent publication and potential of upcoming clinical trials. Now it seems that the FDA has approved this- human clinical trials. Because I am primarily interested in pediatric brain tumors, I rarely get excited about this type of news as in the past it often has taken years to go from first in man studies to our kids. However, this might not be the case with this new agent. It seems that DIPG has been on the minds of the developers of this anti- CD47 antibody already. Stanford already lists this as a topic in their pediatric brain tumor research program!
So what is so special about this anti-CD47 antibody that it has been called the "Holy Grail" of cancer research?
Apparently cells have these proteins on them called CD47 which tell a person's body "don't eat me". Those things that are foreign don't have these proteins so the idea is that the immune system will get destroy them. Cancer cells have alot of these CD47 proteins on them which allows them to continue to survive by tricking the immune system.
A decade ago a Stanford researcher, Irving Weissman, found that leukemia cells had more CD47 on them than normal healthy cells. Later the researchers found that every type of cancer they tested had high levels of CD47 than healthy cells. They developed an anti-CD 47 antibody and tested it on tumor cells in petri dishes. Without the antibody the macrophages (those cells which eating up stuff that shouldn't be there) ignored the cancer cells. However, when the samples had the anit-CD47 antibody included the macrophages destroyed all types of cancer cells. They then tested the agent on mice with similar effects.
There has been some concern that since all cells have CD47 that there could be some significant side effects in normal tissue. Although there has been some transient decreases in blood counts other effects were not seen in mice. The hope is that this will hold true in people as well.
The Stanford team has recieved a four-year $20 million grant for California Institute for Regenerative Medicine to translate these findings from mice to humans. Since Stanford seems to have the funding, the approval and the interest in DIPG this might be research to watch as sometime in the future this agent might become a clinical trial option for kids with DIPG.
Names to Know: It seems the Stanford researchers involved in this project and interested in pediatric DIPG included Michelle Monje, Hans Vogel, Paul Fisher, Albert Wong, Irving Weissman and Phillip Beachy as well as David Rowitch (UCSF).
References:
Antidote: On Cancer and CD47
http://www.mmm-online.com/antidote-on-cancer-and-cd47/article/291840/
CD47 Antibody treatment shrinks or eliminate human cancer tumors in mice (Stanford Video)
https://www.youtube.com/watch?v=EyGWZbmjeR0
So what is so special about this anti-CD47 antibody that it has been called the "Holy Grail" of cancer research?
Apparently cells have these proteins on them called CD47 which tell a person's body "don't eat me". Those things that are foreign don't have these proteins so the idea is that the immune system will get destroy them. Cancer cells have alot of these CD47 proteins on them which allows them to continue to survive by tricking the immune system.
A decade ago a Stanford researcher, Irving Weissman, found that leukemia cells had more CD47 on them than normal healthy cells. Later the researchers found that every type of cancer they tested had high levels of CD47 than healthy cells. They developed an anti-CD 47 antibody and tested it on tumor cells in petri dishes. Without the antibody the macrophages (those cells which eating up stuff that shouldn't be there) ignored the cancer cells. However, when the samples had the anit-CD47 antibody included the macrophages destroyed all types of cancer cells. They then tested the agent on mice with similar effects.
The Stanford team has recieved a four-year $20 million grant for California Institute for Regenerative Medicine to translate these findings from mice to humans. Since Stanford seems to have the funding, the approval and the interest in DIPG this might be research to watch as sometime in the future this agent might become a clinical trial option for kids with DIPG.
Names to Know: It seems the Stanford researchers involved in this project and interested in pediatric DIPG included Michelle Monje, Hans Vogel, Paul Fisher, Albert Wong, Irving Weissman and Phillip Beachy as well as David Rowitch (UCSF).
References:
Antidote: On Cancer and CD47
http://www.mmm-online.com/antidote-on-cancer-and-cd47/article/291840/
CD47 Antibody treatment shrinks or eliminate human cancer tumors in mice (Stanford Video)
https://www.youtube.com/watch?v=EyGWZbmjeR0
Tuesday, May 7, 2013
Part 2- Do the efflux transporters protect the glioma cells?
One of the longstanding questions for DIPG has been."Why doesn't chemo work?"
There have been dozens of trials using all kinds of agents and all of them have virtually the identical Kaplan Meier Curve. The think we don't know is why that is. Often times one hears about something in the blood brain barrier that limits chemotherapy effectiveness. Other times one wonders if it is something in the glioma cells themselves that make them more resistant. The Netherlands paper tried to answer one part of this in better defining ABC transporters in pediatric glioma.
ABC transporters essentially function as little door ways in the cell's membrane either usher substances into the cell (importers) or out of the cells (exporters). The exporters are tone ones that are a problem withe drug resistance. The transporters pump drugs and toxins out of the cells.
There have been 3 different ABC transporters found that escort drugs out of cells. These include P-glcyoprotein (P-gp, ABCB1), breast cancer resistance protein (BCRP, ABCG2) and multidrug resistance associated proteins (MRPs, ABCC1).
This Netherlands study looked at the above 3 ABC transporters in each of the glioma cell lines. All cell lines were negative for P-gp. Only one supratentorial pediatric glioma cell line had BRCP1. High levels of MRP1 was found in 4 of the 9 glioma cell lines. That included 2 of 3 of the DIPG cell lines.
The researchers then looked at actual tumor sample sections to try to determine the amount of ABC transporters in the glioma cells versus the blood vessels. They found that P-gp was not present in most of the glioma cells but was presesnt moderately in the tumor's blood vessels. BCRP1 was not present in the glioma cells but was highly pressent in the blood vessels. Only MRP1 was seen in both the glioma cells and the blood vessels. A chart on the cell lines tested (including 2 of the 3 DIPG samples) is available (click here to see chart).
So, what does this mean for DIPG now?
That is hard to say. So far tying to inhibit the ABC transporters with different agents have been problematic because of significant toxic side effects. These ABC transporters are meant to protect normal cells as well. However, since most of the ABC transporters seem to be in the blood vessels a way around this blood-brain barrier could be direct tumor delivery (i.e., convenction enhanced delivery). The researchers also suggest developing drugs that are not a substract for these transporters could also increase chemotherapy effectiveness.
It does tell us that in trying to find a cure for DIPG that we can not just focus on finding targets within the cancer biology but also need to work on finding ways for new agents to be able reach these targets.
Note: The ATP-binding cassette transporters issue was featured in a recent blogspot regarding a new abstract out of Oren Becher's lab in Duke.
This work was funded by KiKa "Stichting Kinderen Kankervrij"- Dutch Children Cancer-free Foundation.
References:
In vitro drug response and efflux transporters associated with drug resistance in pediatric high grade glioma and diffuse intrinsic pontine glioma
PLoS One. 2013 Apr 29;8(4):e61512. doi: 10.1371/journal.pone.0061512. Print 2013.
Free Full Text- http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3639279/
KiKa Stichting Kinderen Kankervrij- Dutch Children Cancer-free Foundation
http://www.kika.nl/
ABC transporters limit dansantinib efficacy in mice
http://dipg.blogspot.com/2013/04/abc-transported-limit-dasatinib.html
There have been dozens of trials using all kinds of agents and all of them have virtually the identical Kaplan Meier Curve. The think we don't know is why that is. Often times one hears about something in the blood brain barrier that limits chemotherapy effectiveness. Other times one wonders if it is something in the glioma cells themselves that make them more resistant. The Netherlands paper tried to answer one part of this in better defining ABC transporters in pediatric glioma.
ABC transporters essentially function as little door ways in the cell's membrane either usher substances into the cell (importers) or out of the cells (exporters). The exporters are tone ones that are a problem withe drug resistance. The transporters pump drugs and toxins out of the cells.
There have been 3 different ABC transporters found that escort drugs out of cells. These include P-glcyoprotein (P-gp, ABCB1), breast cancer resistance protein (BCRP, ABCG2) and multidrug resistance associated proteins (MRPs, ABCC1).
This Netherlands study looked at the above 3 ABC transporters in each of the glioma cell lines. All cell lines were negative for P-gp. Only one supratentorial pediatric glioma cell line had BRCP1. High levels of MRP1 was found in 4 of the 9 glioma cell lines. That included 2 of 3 of the DIPG cell lines.
The researchers then looked at actual tumor sample sections to try to determine the amount of ABC transporters in the glioma cells versus the blood vessels. They found that P-gp was not present in most of the glioma cells but was presesnt moderately in the tumor's blood vessels. BCRP1 was not present in the glioma cells but was highly pressent in the blood vessels. Only MRP1 was seen in both the glioma cells and the blood vessels. A chart on the cell lines tested (including 2 of the 3 DIPG samples) is available (click here to see chart).
So, what does this mean for DIPG now?
That is hard to say. So far tying to inhibit the ABC transporters with different agents have been problematic because of significant toxic side effects. These ABC transporters are meant to protect normal cells as well. However, since most of the ABC transporters seem to be in the blood vessels a way around this blood-brain barrier could be direct tumor delivery (i.e., convenction enhanced delivery). The researchers also suggest developing drugs that are not a substract for these transporters could also increase chemotherapy effectiveness.
It does tell us that in trying to find a cure for DIPG that we can not just focus on finding targets within the cancer biology but also need to work on finding ways for new agents to be able reach these targets.
Note: The ATP-binding cassette transporters issue was featured in a recent blogspot regarding a new abstract out of Oren Becher's lab in Duke.
This work was funded by KiKa "Stichting Kinderen Kankervrij"- Dutch Children Cancer-free Foundation.
References:
In vitro drug response and efflux transporters associated with drug resistance in pediatric high grade glioma and diffuse intrinsic pontine glioma
PLoS One. 2013 Apr 29;8(4):e61512. doi: 10.1371/journal.pone.0061512. Print 2013.
Free Full Text- http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3639279/
KiKa Stichting Kinderen Kankervrij- Dutch Children Cancer-free Foundation
http://www.kika.nl/
ABC transporters limit dansantinib efficacy in mice
http://dipg.blogspot.com/2013/04/abc-transported-limit-dasatinib.html
Monday, May 6, 2013
New Publication- Are DIPGs just resistant to chemo? No!
Last week the highly productive, DIPG-focused Netherlands group from VU University Medical Center in Amsterdam put forth another publication which happens to have free full text available!
This research focuses on unravelling the reasons why chemotherapy has not been beneficial against DIPGs and pediatric high-grade gliomas. Are DIPGs just resistant to the agents? Or, is it that something is protecting the cells which causes an otherwise good option to be ineffective?
Part 1- Are glioma cells just resistant to chemotherapy?
To look at the first question, the researchers evaluated 9 pediatric glioma cell lines to eliminate questions of adequate drug delivery. Three of these cell lines were from children with DIPGs and 6 were from supratentorial high grade gliomas. Of the 3 DIPG cell lines, all were of different histologic grades- one GBM, one anaplastic astrocytoma and one diffuse fibrillary asrocytomas. Two of these DIPG cell lines came from children who had not had any treatment. The other cell line came from an autopsy donation done approximately 2 hours after death.
In the screening of these cell lines, several agents had high level of killing tumor cells.
When looking at targeted small molecule agents, these did not fare as well as classical chemotherapies. Some did show some efficacy . The best of these was bortezomib which resulted in more than 50% reduction in cell line surival in 6/9 cell lines. There was little or no effect with erlotinib and everolimus. A hypothesis for this result include that the cell lines were not checked for the targets. If there was a matching of targets and agents the results might have been better. Also since there are multiple messed up pathways combined therapy is generally thought to be needed and a single agents is very unlikely to be effective.
In looking at classic chemotherapy agents, melphalan was the only drug that had significiant toxicity in all cell lines. Interestly that is the exact agent of the new intra-arterial Hopkins DIPG trial!
Other agents that were found to have a signficant effect included doxorubicin, mitoxantrone and BCNU. The next level included etoposide, thiotepa and carboplatin. Carboplatin was of special note since that is what the UK in their CED report.
What this means for DIPG is that DIPG is not necessarily resistant to chemotherapy! Effective drgus might not be the biggest hurdle for a cure for DIPG. It might be getting them to the tumor cells.
This work was funded by KiKa "Stichting Kinderen Kankervrij"- Dutch Children Cancer-free Foundation.
Tomorrow.....
Part 2- Do the efflux transporters protect the glioma cells?
References:
In vitro drug response and efflux transporters associated with drug resistance in pediatric high grade glioma and diffuse intrinsic pontine glioma
PLoS One. 2013 Apr 29;8(4):e61512. doi: 10.1371/journal.pone.0061512. Print 2013.
Free Full Text- http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3639279/
KiKa Stichting Kinderen Kankervrij- Dutch Children Cancer-free Foundation
http://www.kika.nl/
This research focuses on unravelling the reasons why chemotherapy has not been beneficial against DIPGs and pediatric high-grade gliomas. Are DIPGs just resistant to the agents? Or, is it that something is protecting the cells which causes an otherwise good option to be ineffective?
Part 1- Are glioma cells just resistant to chemotherapy?
To look at the first question, the researchers evaluated 9 pediatric glioma cell lines to eliminate questions of adequate drug delivery. Three of these cell lines were from children with DIPGs and 6 were from supratentorial high grade gliomas. Of the 3 DIPG cell lines, all were of different histologic grades- one GBM, one anaplastic astrocytoma and one diffuse fibrillary asrocytomas. Two of these DIPG cell lines came from children who had not had any treatment. The other cell line came from an autopsy donation done approximately 2 hours after death.
In the screening of these cell lines, several agents had high level of killing tumor cells.
When looking at targeted small molecule agents, these did not fare as well as classical chemotherapies. Some did show some efficacy . The best of these was bortezomib which resulted in more than 50% reduction in cell line surival in 6/9 cell lines. There was little or no effect with erlotinib and everolimus. A hypothesis for this result include that the cell lines were not checked for the targets. If there was a matching of targets and agents the results might have been better. Also since there are multiple messed up pathways combined therapy is generally thought to be needed and a single agents is very unlikely to be effective.
In looking at classic chemotherapy agents, melphalan was the only drug that had significiant toxicity in all cell lines. Interestly that is the exact agent of the new intra-arterial Hopkins DIPG trial!
Other agents that were found to have a signficant effect included doxorubicin, mitoxantrone and BCNU. The next level included etoposide, thiotepa and carboplatin. Carboplatin was of special note since that is what the UK in their CED report.
What this means for DIPG is that DIPG is not necessarily resistant to chemotherapy! Effective drgus might not be the biggest hurdle for a cure for DIPG. It might be getting them to the tumor cells.
This work was funded by KiKa "Stichting Kinderen Kankervrij"- Dutch Children Cancer-free Foundation.
Tomorrow.....
Part 2- Do the efflux transporters protect the glioma cells?
References:
In vitro drug response and efflux transporters associated with drug resistance in pediatric high grade glioma and diffuse intrinsic pontine glioma
PLoS One. 2013 Apr 29;8(4):e61512. doi: 10.1371/journal.pone.0061512. Print 2013.
Free Full Text- http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3639279/
KiKa Stichting Kinderen Kankervrij- Dutch Children Cancer-free Foundation
http://www.kika.nl/
Thursday, May 2, 2013
DIPG Collaborative Symposium Begins in Cincinnati
Tomorrow the 2nd DIPG Collaborative Symposium begins in Cincinnati. This two track program brings together doctors and researchers in one track and foundations and parents in another (with a potential networking dinner Friday evening). The goal is to be able to "efficiently fund and inspire diffuse intrinsic pontine glioma cancer research in hopes of finding a wider cure for cancer". This year there is expected to be approximately 140 from 7 countries. With the diverse agenda with international speakers on the forefront of DIPG research, I suspect it will be an exciting place to be for those interested in pediatric diffuse intrinsic pontine glioma.
The 2011 DIPG Collaborative Symposium brought about some substantive advances in the infrastructure critical for DIPG research including the DIPG Registry, the DIPG Preclinical Consortium, and the DIPG Genomics Repository.
This meeting starts Friday morning with a Keynote Lecture from Canadian geneticist and researcher, Nada Jaboda MD PhD. Although the topic has not been release I am thinking- H3.3,K27M and epigenetics. To get a taste of the work she has been doing in unravelling pediatric vs adult astrocytomas (including DIPG) there is a NYU Grand Rounds titled "Rewiring the Epigenome in Pediatric and Young High Grade Astrocytomas" presented on December 18, 2012. (click here to watch the video) This work has the potential to change how we approach and treat DIPGs.
The meeting continues with a update of research funded through the collaborative and the Cure Starts Now:
Preclinica/Traslantional
* Xiao-Nan Li(Baylor)- an oncolytic picorna virus in a DIPG xenograft mouse model.
* Oren Becher (Duke)- systemic and direct delivery of a PDFGR-alpha antibody.
* Suzanne Baker (St Jude)- establishment and characterization of DIPG renewable tissue resources
* Patricia Baxter (Texas)- Novel BMI-1 inhibitors in brainstem xenograft mouse models.
* Michele Monje (Stanford)- combined targeted therapy for cellular subpopulations in DIPG.
Clinical
Mark Souweidane (Cornell)- CED trial update
multiple- DIPG Registry update
This will be followed by various other sessions especially revolving around biopsy, biologic understanding of DIPG and current trends in clinical trials. One of the most anticipated things for me is the Xerecept session on Friday afternoon. It has been years of waiting for this drug to see if it can decease the suffering caused by steroids in so many DIPG children (click here for video). Hopefully something substantive will come from this session.
The other track- the parents and foundation track- will meet primarily on Saturday to discuss the Collaborative objectives, structure, prior efforts and success.
The event will culminate with a Once in a Lifetime Gala which looks to be spectacular (sold out- 1200 seat). This year's three ring circus them features the Cincinnati Circus and Nik Walenda.
Reference:
DIPG Collaborative Symposium Meeting Agenda
https://csn.donordrive.com/assets/csn/files/$cms$/100/2097.pdf
DIPG Preclinical Consortium-
http://pptiohsu.blogspot.com/2011/12/open-science-forum-dipg-preclinical.html
DIPG Registry-
http://www.dipgregistry.org/
The 2011 DIPG Collaborative Symposium brought about some substantive advances in the infrastructure critical for DIPG research including the DIPG Registry, the DIPG Preclinical Consortium, and the DIPG Genomics Repository.
This meeting starts Friday morning with a Keynote Lecture from Canadian geneticist and researcher, Nada Jaboda MD PhD. Although the topic has not been release I am thinking- H3.3,K27M and epigenetics. To get a taste of the work she has been doing in unravelling pediatric vs adult astrocytomas (including DIPG) there is a NYU Grand Rounds titled "Rewiring the Epigenome in Pediatric and Young High Grade Astrocytomas" presented on December 18, 2012. (click here to watch the video) This work has the potential to change how we approach and treat DIPGs.
The meeting continues with a update of research funded through the collaborative and the Cure Starts Now:
Preclinica/Traslantional
* Xiao-Nan Li(Baylor)- an oncolytic picorna virus in a DIPG xenograft mouse model.
* Oren Becher (Duke)- systemic and direct delivery of a PDFGR-alpha antibody.
* Suzanne Baker (St Jude)- establishment and characterization of DIPG renewable tissue resources
* Patricia Baxter (Texas)- Novel BMI-1 inhibitors in brainstem xenograft mouse models.
* Michele Monje (Stanford)- combined targeted therapy for cellular subpopulations in DIPG.
Clinical
Mark Souweidane (Cornell)- CED trial update
multiple- DIPG Registry update
This will be followed by various other sessions especially revolving around biopsy, biologic understanding of DIPG and current trends in clinical trials. One of the most anticipated things for me is the Xerecept session on Friday afternoon. It has been years of waiting for this drug to see if it can decease the suffering caused by steroids in so many DIPG children (click here for video). Hopefully something substantive will come from this session.
The other track- the parents and foundation track- will meet primarily on Saturday to discuss the Collaborative objectives, structure, prior efforts and success.
The event will culminate with a Once in a Lifetime Gala which looks to be spectacular (sold out- 1200 seat). This year's three ring circus them features the Cincinnati Circus and Nik Walenda.
Reference:
DIPG Collaborative Symposium Meeting Agenda
https://csn.donordrive.com/assets/csn/files/$cms$/100/2097.pdf
DIPG Preclinical Consortium-
http://pptiohsu.blogspot.com/2011/12/open-science-forum-dipg-preclinical.html
DIPG Registry-
http://www.dipgregistry.org/
Friday, April 26, 2013
Building a Post-Mortem DIPG Tissue Research Progam
Perhaps the biggest rate limiting step in DIPG research has been the lack of tissue. Without tissue, what is there really to study in the basic science realm? However, DIPGs pose significant hurdles in getting tissue as biopsies have not been traditionally preformed and post-mortem donations have infrequently been requested.
Over the years there have been many barriers to post-mortem donations. Some lacked knowledge- the medical system just didn't know that any research was actively being done. Some didn't believe that usable samples could be obtained for research. Some didn't know how to logistically make this happen especially if the child died at home and the research was being done somewhere else in the country. Some didn't know how or when to approach the parents on this delicate topic.
There have been a few places that have worked to collect post-mortem DIPG samples for research. One of the most impressive total package programs is Children's National Medical Center. These researchers have taken on each obstacle and overcome them.
For me the first hurdle is if there is any DIPG research being done at that institution. It doesn't do us any good to have a sample donated and then it sits in the freezer. At Children's National Medical Center there was an interested researcher, Javad Nazarian, who already had a funded grant from the Childhood Brain Tumor Foundation to study DIPGs. This meant there was some money and someone to do the research but there are still huge problems- how does anyone know you need the samples and how do you obtain them.
A researcher-clinician partnership was lead to a multi-disciplinary team. This team included a pediatric neurosurgeon (Suresh Magee) and two pediatric neuro-oncologists (Roger Packer and Brain Rood) as well as Javad Nazarian.
To address the awareness issue, three things were done. First, the researchers developed an IRB protocol and took the innovative step to have it placed in clinicaltrials.gov. In this way, interested physicians and parents might more easily find out about the research and have the contact information. Secondly, they developed a brochure detailing the information which parents could take away and review at a later time. By the way, it also had a 24 hour contact pager to help facilitate logistics. Thirdly, they included their information on the Kid V Cancer site on research needing tissue.
The logistical problems of having a child die at home and then donating a post-mortem sample are complex; but, they are overcomeable. It is easier to overcome them with some advanced planning. Transportation is one of the recurrent hurdles as often times if the child will have to be transported to the hospital first then this is not covered by insurance. There have been foundations that have stepped up to fund these expenses so that this research will not be stopped. In this case, the Musella Foundation has supported that aspect of the program.
And now to maximize research, Children's National Medical Center is part of a DIPG tissue sharing consortium called the Mid-Atlantic DIPG Consortium (MADC). The other two institutions are Johns Hopkins and the National Institute of Health- Pediatric Oncology Branch. This collaboration must be highly successful as several DIPG abstracts have come out for a series of spring meetings including AACR, USCAP and the SNO/PBTF Pediatric Neuro-Oncology Basic and Translational Research Conference.
If asked, some families will donate their child's tumor. It will not be all, but many will and it is made so much more possible with a program in place to address the issues. Kid's V Cancer is a good place to find out more about autopsy donation- both for families (FAQs and others experiences) as well as physicians (how to ask and autopsy donation checklist).
Thank you Children's National Medical Center for putting this program in place to advance DIPG research.
References:
Molecular Analysis of Samples from Patients with Diffuse Intrinsic Pontine Glioma and Brainstem Glioma
Brochure: http://www.virtualtrials.com/pdf/dipg.pdf
Over the years there have been many barriers to post-mortem donations. Some lacked knowledge- the medical system just didn't know that any research was actively being done. Some didn't believe that usable samples could be obtained for research. Some didn't know how to logistically make this happen especially if the child died at home and the research was being done somewhere else in the country. Some didn't know how or when to approach the parents on this delicate topic.
There have been a few places that have worked to collect post-mortem DIPG samples for research. One of the most impressive total package programs is Children's National Medical Center. These researchers have taken on each obstacle and overcome them.
For me the first hurdle is if there is any DIPG research being done at that institution. It doesn't do us any good to have a sample donated and then it sits in the freezer. At Children's National Medical Center there was an interested researcher, Javad Nazarian, who already had a funded grant from the Childhood Brain Tumor Foundation to study DIPGs. This meant there was some money and someone to do the research but there are still huge problems- how does anyone know you need the samples and how do you obtain them.
A researcher-clinician partnership was lead to a multi-disciplinary team. This team included a pediatric neurosurgeon (Suresh Magee) and two pediatric neuro-oncologists (Roger Packer and Brain Rood) as well as Javad Nazarian.
To address the awareness issue, three things were done. First, the researchers developed an IRB protocol and took the innovative step to have it placed in clinicaltrials.gov. In this way, interested physicians and parents might more easily find out about the research and have the contact information. Secondly, they developed a brochure detailing the information which parents could take away and review at a later time. By the way, it also had a 24 hour contact pager to help facilitate logistics. Thirdly, they included their information on the Kid V Cancer site on research needing tissue.
The logistical problems of having a child die at home and then donating a post-mortem sample are complex; but, they are overcomeable. It is easier to overcome them with some advanced planning. Transportation is one of the recurrent hurdles as often times if the child will have to be transported to the hospital first then this is not covered by insurance. There have been foundations that have stepped up to fund these expenses so that this research will not be stopped. In this case, the Musella Foundation has supported that aspect of the program.
And now to maximize research, Children's National Medical Center is part of a DIPG tissue sharing consortium called the Mid-Atlantic DIPG Consortium (MADC). The other two institutions are Johns Hopkins and the National Institute of Health- Pediatric Oncology Branch. This collaboration must be highly successful as several DIPG abstracts have come out for a series of spring meetings including AACR, USCAP and the SNO/PBTF Pediatric Neuro-Oncology Basic and Translational Research Conference.
If asked, some families will donate their child's tumor. It will not be all, but many will and it is made so much more possible with a program in place to address the issues. Kid's V Cancer is a good place to find out more about autopsy donation- both for families (FAQs and others experiences) as well as physicians (how to ask and autopsy donation checklist).
Thank you Children's National Medical Center for putting this program in place to advance DIPG research.
References:
Molecular Analysis of Samples from Patients with Diffuse Intrinsic Pontine Glioma and Brainstem Glioma
Brochure: http://www.virtualtrials.com/pdf/dipg.pdf
Clinicaltrials.gov http://clinicaltrials.gov/ct2/show/NCT01106794
Selected DIPG articles/abstracts from Javad Nazarian and group:
Protein profiling of formalin fixed paraffin embedded tissue: Identification of potential biomarkers for pediatric brain stem glioma
http://www.ncbi.nlm.nih.gov/pubmed/21136889
Insights into pediatric diffuse intrinsic pontine glioma through proteomic analysis of spinal fluid
http://www.ncbi.nlm.nih.gov/pubmed/22492959
Targeting the Notch and mTor pathways in diffuse intrinsic pontine glioma
http://www.abstractsonline.com/Plan/ViewAbstract.aspx?mID=3086&sKey=6fa486c2-2701-4a76-8431-b22144df78e4&cKey=c3e199ac-82f7-486d-9d65-bb1c13525e3b&mKey=%7b9B2D28E7-24A0-466F-A3C9-07C21F6E9BC9%7d
NG2 Upregulation in Pediatric Diffuse Intrinsic Pontine Glioma and Its Role in Tumorigenecity in Vivo
https://soc-neuro-onc.conference-services.net/reports/template/onetextabstract.xml?xsl=template/onetextabstract.xsl&conferenceID=3467&abstractID=740466
Selected DIPG articles/abstracts from Javad Nazarian and group:
Protein profiling of formalin fixed paraffin embedded tissue: Identification of potential biomarkers for pediatric brain stem glioma
http://www.ncbi.nlm.nih.gov/pubmed/21136889
Insights into pediatric diffuse intrinsic pontine glioma through proteomic analysis of spinal fluid
http://www.ncbi.nlm.nih.gov/pubmed/22492959
Targeting the Notch and mTor pathways in diffuse intrinsic pontine glioma
http://www.abstractsonline.com/Plan/ViewAbstract.aspx?mID=3086&sKey=6fa486c2-2701-4a76-8431-b22144df78e4&cKey=c3e199ac-82f7-486d-9d65-bb1c13525e3b&mKey=%7b9B2D28E7-24A0-466F-A3C9-07C21F6E9BC9%7d
NG2 Upregulation in Pediatric Diffuse Intrinsic Pontine Glioma and Its Role in Tumorigenecity in Vivo
https://soc-neuro-onc.conference-services.net/reports/template/onetextabstract.xml?xsl=template/onetextabstract.xsl&conferenceID=3467&abstractID=740466
Monday, April 22, 2013
Genomic Landscape of treatment-naive DIPG Biopsy Sample
Yesterday I posted about the first International DIPG conference held in 2009 in Barcelona, Spain. During that conference, Dr. Jaume Mora moderated a two hour session discussing proposals for common international/interdisciplinary DIPG research agenda items. Many things seems to be evolving collaboratively in the European DIPG arena. The action points of the 2012 Barcelona meeting are impressive (click here to see).
In looking at the SNO/PBTF Pediatric Neuro-Oncology Basic Science and Translational Research Conference abstracts, I noticed a somewhat unusual abstract. This abstract (to me) highlighted the internationally collaborative nature of DIPG research today. The authors were from 4 countries- France, England, Spain and Canada (Vancouver)!
This abstract examined the whole genome sequencing of 20 pre-treatment DIPG samples (all high grade gliomas) obtained by stereotactic biopsy in France.
Although the abstract word limits don't allow for in-depth understand of the work, there were some interesting things. First, the K27M mutations was seen in all cases.
It would seem that there were some cases where the initial untreated specimen was compared with a post-mortem sample. Not really unexpected, the autopsy sample has increased number of mutations. The authors write conclude that DIPG biopsy provides an opportunity to study the genome and identify possible intervention targets.
Something more fascinating to me - and not part of the abstract - is the question of how did these researcher get together to do this research for this abstract. I believe the children from Spain might be offered the option of going to France for biopsy. I believe that the children in the UK were offered that in that past as well. In addition, Chris Jones was tasked as the responsible member for the biopsy biological studies (for SIOP-E DIPG Network). In his Barcelona 2012 presentation, Chris Jones talked about "What to Do With Tissue". In this, he did mention transatlantic collaboration.
The thing that I wonder about though- is British Columbia. Sick Kids has been a powerhouse of DIPG research out of Canada. It would seem that Vancouver might be a place to watch as well.
Reference:
The Genomic Landscape of treatment-naive DIPG Biopsy Sample
https://soc-neuro-onc.conference-services.net/reports/template/onetextabstract.xml?xsl=template/onetextabstract.xsl&conferenceID=3467&abstractID=738496
Saturday, April 20, 2013
ABC transporters limit dasatinib efficacy in mice
Ever since the first whole genome DIPG profile paper from Sick Kids in Canada came out in 2010, there has been interest in platelet derived growth factor receptor alpha. This is because all the samples (9 post-mortem and two pretreated surgical samples) showed PDGRF-alpha expression. The hope was that PDGFR-alpha could be a target to make a difference in DIPG. The search was on for an agent to try.
An available PDGFR-alpha antagionist was found, dasantinib. This Bristol-Myers-Squibb drug is marketed under the name Sprycel for the indication chronic myelogenous leukemia (CML). When looking in clinicaltrials.gov, there are already 219 trials up for this drug. It has been already been tried on adults and in children. The availability and prior use seemed to make this drug easily translatable to trials for DIPG kids. St. Jude has completed one trials using dasatinib and vandetanib and another open trial using dasatinib and crizotinib.
The thing about dasatinib is that it seems that it can be pumped out a a cell because by ABC (ATP-binding cassette) transporters. This is a "superfamily" of proteins that transport things (such as sugars, lipids, toxins and drugs) across the cell membranes. Three of these ABC transporters are known to cause chemoresistance. These are MDR, ABDG2 and ABCB1. Datinib is known to be a substrate for MDR and ABCG2.
An abstract from Oren Becher's lab at Duke is going to be presented at the SNO/PBTF Pediatric Neuro-Oncology Basic and Translational Research Conference next month in Fort Lauderdale looking at whether altering these transport proteins can alter dasatinib activity. They did this by making DIPG mouse models that were deficient in the transporters ABCG2 and MDR. At the first signs of tumor, these mice were given dasantinib. The mice were sacrified a day later and the brains examined for specific things (caspase-3 and phospho-histone H3).
There was no difference in phosoph-histone H3 whether the transporter was present or not in the mice. However, mice without the transporter had a 20 fold increase in caspace C levels as compared to those mice with the transporter.
These researchers concluded that these ABC transporters impact dasatinib's efficacy. Further study is need to see if transporter-deficient mice can live longer when treated with dasatinib and if a transporter inhibitor (such as elacridar) can increase efficacy hopefully increasing survival.
Reference:
ABC transporters, ABCG2 and MDR, limit the efficacy of dasatinib in a diffuse intrinsic pontine glioma (DIPG) mouse model
https://soc-neuro-onc.conference-services.net/reports/template/onetextabstract.xml?xsl=template/onetextabstract.xsl&conferenceID=3467&abstractID=740371
Brain distribution and bioavailability of elacridar after different routes of administration in the mouse
http://www.ncbi.nlm.nih.gov/pubmed/22611067
Oren Becher Lab at Duke
http://pediatrics.duke.edu/faculty/details/0541183
Wednesday, March 27, 2013
St Jude Study on Kid's Bones in Antiangiogenesis Trials
1- Angiogenesis (can be thought of as new blood vessel formation) is considered to be a key process in the development and growth of glioblastomas.
2- Most DIPGs so far have been found to be glioblastomas.
Given these above two facts, researchers at St Jude Children Research Hospital in Memphis designed two phase 1 trials using antiangiogenic drugs in during radiation and after for newly diagnosed kids with DIPG tumors. The first study used vandetanib and the second used a combination of vandetanib and dasatinib. Both of these drugs are oral and affect targeted areas in the molecular pathways. Vandetanib is a potent VEGFR-2 (vascular endothelial growth factor receptor-2) inhibitor.
Pediatric patients are not just little adults. A significant difference is that kids grow and mature. This could be a problem with antiangiogenesis drugs as animal studies showed that this type of inhibition could negatively affect skeletal growth. Since little had been reported on the effects of these drugs on children's skeletal development, St Jude researchers included this as part of their study.
There were 59 patients (32 girls and 27 boys) evaluated with a total of 119 MRIs and 51 patients had plain knee x-rays. The children ranged from 2.4-17.6 years (median 6.2 years of age). The median treatment was 205 days. Of note, two patients had not progressed- one was 18 months out from diagnosis and the other 60 months.
All of the kids had MRIs of the knees at baseline and 50 had MRIs at 16-19 weeks of therapy. MRIs showed more abnormalities than plain films. MRIs showed:
Plain radiographs did not show these abnormalities.
Although this was a short followup time, this is the largest group of kids studied for skeletal changes on these antiangiogenesis agents. It seems clear that MRI is better in picking up abnormalities. The authors encourage more long term follow-up monitoring in pediatric patients taking these agents.
Note- this work was supported in part by US National Institute of Health Cancer Center Suppport (CORE) Grant P30 CA-21765, a Center of Excellence grant from the State of Tennessee, AMerican Lebanese Syrian Associated Charities (ASLAC), Noyes Brain Tumor Foundation, Musicians Against Childhood Cancer (MACC), AstraZeneca and The Cure Starts Now Foundation.
Reference:
Magnetic Resonance Imaging Is the Preferred Method to Assess Treatment-Related Skeletal Changes in Children with Brain Tumors
Pediatr Blood Cancer. 2013 Mar 22. doi: 10.1002/pbc.24536. [Epub ahead of print]
Department of Radiological Sciences, St. Jude Children's Research Hospital
Kaste SC, Kaufman RA, Gajjar A, Broniscer A.
http://www.ncbi.nlm.nih.gov/pubmed/23526749
What is VEGF? http://www.news-medical.net/health/What-is-VEGF.aspx
St Jude Vandetanib Trials-
http://clinicaltrials.gov/ct2/show/NCT00472017?term=vandetanib+St+Jude&rank=1
2- Most DIPGs so far have been found to be glioblastomas.
Given these above two facts, researchers at St Jude Children Research Hospital in Memphis designed two phase 1 trials using antiangiogenic drugs in during radiation and after for newly diagnosed kids with DIPG tumors. The first study used vandetanib and the second used a combination of vandetanib and dasatinib. Both of these drugs are oral and affect targeted areas in the molecular pathways. Vandetanib is a potent VEGFR-2 (vascular endothelial growth factor receptor-2) inhibitor.
Pediatric patients are not just little adults. A significant difference is that kids grow and mature. This could be a problem with antiangiogenesis drugs as animal studies showed that this type of inhibition could negatively affect skeletal growth. Since little had been reported on the effects of these drugs on children's skeletal development, St Jude researchers included this as part of their study.
There were 59 patients (32 girls and 27 boys) evaluated with a total of 119 MRIs and 51 patients had plain knee x-rays. The children ranged from 2.4-17.6 years (median 6.2 years of age). The median treatment was 205 days. Of note, two patients had not progressed- one was 18 months out from diagnosis and the other 60 months.
All of the kids had MRIs of the knees at baseline and 50 had MRIs at 16-19 weeks of therapy. MRIs showed more abnormalities than plain films. MRIs showed:
- 1 patient with premature physeal fusion (the growth plate closed too soon),
- 1 patient focal thickening of the growth plate,
- 2 patients with bony spicules across the growth plate,
- 8 patients with osteonecrosis (one was present at enrollment in the study).
Plain radiographs did not show these abnormalities.
Although this was a short followup time, this is the largest group of kids studied for skeletal changes on these antiangiogenesis agents. It seems clear that MRI is better in picking up abnormalities. The authors encourage more long term follow-up monitoring in pediatric patients taking these agents.
Note- this work was supported in part by US National Institute of Health Cancer Center Suppport (CORE) Grant P30 CA-21765, a Center of Excellence grant from the State of Tennessee, AMerican Lebanese Syrian Associated Charities (ASLAC), Noyes Brain Tumor Foundation, Musicians Against Childhood Cancer (MACC), AstraZeneca and The Cure Starts Now Foundation.
Reference:
Magnetic Resonance Imaging Is the Preferred Method to Assess Treatment-Related Skeletal Changes in Children with Brain Tumors
Pediatr Blood Cancer. 2013 Mar 22. doi: 10.1002/pbc.24536. [Epub ahead of print]
Department of Radiological Sciences, St. Jude Children's Research Hospital
Kaste SC, Kaufman RA, Gajjar A, Broniscer A.
http://www.ncbi.nlm.nih.gov/pubmed/23526749
What is VEGF? http://www.news-medical.net/health/What-is-VEGF.aspx
St Jude Vandetanib Trials-
http://clinicaltrials.gov/ct2/show/NCT00472017?term=vandetanib+St+Jude&rank=1
Tuesday, March 26, 2013
The TIssue Issue- Molecular Biology of DIPG
DIPG as a chapter section regarding new molecular targets and treatments for brain tumors!
Chapter 20: New Molecular Targets and Treatment for Pediatric Brain Tumors by James T. Rutka
in Evolution of Molecular Biology of Brain Tumors and the Therapeutic Implications edited by Terry Lichtor and published on February 27, 2013
The main reason for lack of advancement on DIPG has been the lack of tumor tissue (not lack of funding, not lack of interest and not lack of trying). The almost total absence of tumor tumor tissue meant there was no feasible way to develop specific research on this devastating pediatric tumor. Let me emphasize that again-- All basic science research with DIPG was essentially impossible without tissue. However, the past half decade has seen rapid changes and unprecedented collaboration to get tissue both by biopsy and autopsy.
Timeline-
* 2004- the French decided it the molecular age of tumor biology has reached a stage to reinstitute biopsies. Simultaneously in North America several hospitals (Sick Kids, St Jude, NIH) made a concerted effort to obtain post-mortem samples.
* Jauary 2009- Dylan Jewett's tumor was donated to Standford.
* February 2010, the first ever DIPG genomic study was published by Sick Kids.
* March 2011, Stanford released news that they had developed a first pediatric DIPG cell line and animal model from the previously donated tumor.
* Today there are more than 30 DIPG cell lines, several institutions that have developed animal models and a handful of DIPG molecular biology papers have been published.
Chapter Highlightss
- From recent studies it has become common knowledge that pediatric brain tumor (including DIPG) are different from similarly appearing adult tumors. Not only are pediatric tumors different than adults, but also DIPG are genetically different from other pediatric gliomas
- A growing list of different pathways and factors are being described. DIPG discussions are soon going to routinely contain a confusing concoction of letters,number, factors and receptors- EGFR, PDGFA, recetpor tyorosine kinase, retinoblastoma protein, PARP-1, MET and insulin-like growth factor receptor 1. All these are parts of pathways driving tumors and all have been found in a percentage of DIPGs.
- Drugable targets in DIPG tumors have been found in the molecular biology evaluation of DIPGs. The paper lists the overall survival and references for seven different clinical trials since 2007 using different targeted drugs- imatinib, tififanib, genfitinib, vandetanib, erlotinib and nimozumab. In some cases, a subset of patients have been found to survive longer than expected. Most of these trials though were done blindly so individual patient's molecular biology is not known.
- Recently the first mutated oncogene in DIPG was described- P13KCA.
- The chapter also highlights the challenge of getting these agents into the pons. The blood brain barrier seems to severely limit access to the pons. Convection-enhanced delivery and nanoparticles were specifically mentioned as techniques to consider in DIPG.
Chapter Author: James T Rutka- Division of Neurosurgery and Labatt Brain Tumor Centre, The Hospital for Sick Children, University of Toronto, Canada
References:
Claudia C. Faria, Christian A. Smith and James T. Rutka (2013). New Molecular Targets and Treatments for Pediatric Brain Tumors, Evolution of the Molecular Biology of Brain Tumors and the Therapeutic Implications, Dr. Terry Lichtor (Ed.), ISBN: 978-953-51-0989-1, InTech, DOI: 10.5772/53300. Available from: http://www.intechopen.com/books/evolution-of-the-molecular-biology-of-brain-tumors-and-the-therapeutic-implications/new-molecular-targets-and-treatments-for-pediatric-brain-tumors
Sunday, March 24, 2013
New NIH/Hopkins Abstract presented at USCAP
Earlier this month the 102nd Annual Meeting of the United States and Canadian Academy of Pathology was held in Baltimore, Maryland. Frankly, this isn't a meeting that I have ever followed because I don't remember a pediatric brain tumors presence previously-- and certainly not the unresectable, rarely biopsied diffuse intrinsic pontine glioma. This just isn't something that pathologist do. Yet, on a Wednesday afternoon, a DIPG poster- Histology and Immunohistochemical Profile of Diffuse Intrinsic Pontine Gioma- took its place among a myriad of other neuropathology presentations.
This joint NIH/Hopkins abstract presented the characteristics of of 24 DIPGs autopsy specimens. Histologic results are as follows:
17- GBM with 14/17 having pseudopallisading necrosis and 12/17 with vascular proliferation
5- anaplastic astrocytoma
1- low grade (WHO II)
1- intermediate (features of WHO II and III)
Immunohistochemical results revealed all were GFAP positive. Regarding the stem cell markers, 22/24 were Oligo2 positive and 19/24 were Sox2 positive. In addition, 20/24 16/24 were positive for p53 and EGFR respectively.
What does all this mean? Well, all of these were gliomas. The high level of stem cell markers would seem to support the hypothesis of a tumor stem cell origin for DIPG. Understanding the pathways that have gone awry with DIPG we might be able to better identify prognostic markers and potential therapeutic targets.
It also means that DIPG research has began to make strides in tumor biology. In the future, people that really want to understand DIPG research will have to gain an understanding in pathways and cancer stem cells. Excellent chapters by Mark Kieran and Michelle Monje are in the ACCO book Understanding the Journey.
Additionally, it means that 24 parents selflessly gave an ultimate gife in the fight against DIPG-without which I don't see any possible way we could get to a cure. There is no doubt we could not have gotten to this research. It is with deep gratitude that I recognized these families that endured the unimaginable and jumped over logistical hurdles to make a difference.
Note- Interestingly Oligo2 importance with PDFRA was just mentioned on Friday here with the UCSF research.
Reference-
Abstract- http://www.abstracts2view.com/uscap13/view.php?nu=USCAP13L_1726
UCSF Research- http://dipg.blogspot.com/2013/03/focus-on-research-hashizume-laboratory.htm
ACCO DIPG Book-
http://myemail.constantcontact.com/New-FREE-resource-for-DIPG-Families-.html?soid=1102946333954&aid=k63YiippnW8
This joint NIH/Hopkins abstract presented the characteristics of of 24 DIPGs autopsy specimens. Histologic results are as follows:
17- GBM with 14/17 having pseudopallisading necrosis and 12/17 with vascular proliferation
5- anaplastic astrocytoma
1- low grade (WHO II)
1- intermediate (features of WHO II and III)
Immunohistochemical results revealed all were GFAP positive. Regarding the stem cell markers, 22/24 were Oligo2 positive and 19/24 were Sox2 positive. In addition, 20/24 16/24 were positive for p53 and EGFR respectively.
What does all this mean? Well, all of these were gliomas. The high level of stem cell markers would seem to support the hypothesis of a tumor stem cell origin for DIPG. Understanding the pathways that have gone awry with DIPG we might be able to better identify prognostic markers and potential therapeutic targets.
It also means that DIPG research has began to make strides in tumor biology. In the future, people that really want to understand DIPG research will have to gain an understanding in pathways and cancer stem cells. Excellent chapters by Mark Kieran and Michelle Monje are in the ACCO book Understanding the Journey.
Additionally, it means that 24 parents selflessly gave an ultimate gife in the fight against DIPG-without which I don't see any possible way we could get to a cure. There is no doubt we could not have gotten to this research. It is with deep gratitude that I recognized these families that endured the unimaginable and jumped over logistical hurdles to make a difference.
Note- Interestingly Oligo2 importance with PDFRA was just mentioned on Friday here with the UCSF research.
Reference-
Abstract- http://www.abstracts2view.com/uscap13/view.php?nu=USCAP13L_1726
UCSF Research- http://dipg.blogspot.com/2013/03/focus-on-research-hashizume-laboratory.htm
ACCO DIPG Book-
http://myemail.constantcontact.com/New-FREE-resource-for-DIPG-Families-.html?soid=1102946333954&aid=k63YiippnW8
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