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illustration of brain showing cerebellum

Focusing on the “little brain” to rescue cognition

illustration of brain showing cerebellum

Research faculty at Children’s National in Washington, D.C., with colleagues recently published a review article in Nature Reviews Neuroscience that covers the latest research about how abnormal development of the cerebellum leads to a variety of neurodevelopmental disorders.

Cerebellum translates as “little brain” in Latin. This piece of anatomy – that appears almost separate from the rest of the brain, tucked under the two cerebral hemispheres – long has been known to play a pivotal role in voluntary motor functions, such as walking or reaching for objects, as well as involuntary ones, such as maintaining posture.

But more recently, says Aaron Sathyanesan, Ph.D., a postdoctoral research fellow at the Children’s Research Institute, the research arm of Children’s National  in Washington, D.C., researchers have discovered that the cerebellum is also critically important for a variety of non-motor functions, including cognition and emotion.

Sathyanesan, who studies this brain region in the laboratory of Vittorio Gallo, Ph.D., Chief Research Officer at Children’s National and scientific director of the Children’s Research Institute, recently published a review article with colleagues in Nature Reviews Neuroscience covering the latest research about how altered development of the cerebellum contributes to a variety of neurodevelopmental disorders.

These disorders, he explains, are marked by problems in the nervous system that arise while it’s maturing, leading to effects on emotion, learning ability, self-control, or memory, or any combination of these. They include diagnoses as diverse as intellectual disability, autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder and Down syndrome.

“One reason why the cerebellum might be critically involved in each of these disorders,” Sathyanesan says, “is because its developmental trajectory takes so long.”

Unlike other brain structures, which have relatively short windows of development spanning weeks or months, the principal cells of the cerebellum – known as Purkinje cells – start to differentiate from stem cell precursors at the beginning of the seventh gestational week, with new cells continuing to appear until babies are nearly one year old.  In contrast, cells in the neocortex, a part of the brain involved in higher-order brain functions such as cognition, sensory perception and language is mostly finished forming while fetuses are still gestating in the womb.

This long window for maturation allows the cerebellum to make connections with other regions throughout the brain, such as extensive connections with the cerebral cortex, the outer layer of the cerebrum that plays a key role in perception, attention, awareness, thought, memory, language and consciousness. It also allows ample time for things to go wrong.

“Together,” Sathyanesan says, “these two characteristics are at the root of the cerebellum’s involvement in a host of neurodevelopmental disorders.”

For example, the review article notes, researchers have discovered both structural and functional abnormalities in the cerebellums of patients with ASD. Functional magnetic resonance imaging (MRI), an imaging technique that measures activity in different parts of the brain, suggests that significant differences exist between connectivity between the cerebellum and cortex in people with ASD compared with neurotypical individuals. Differences in cerebellar connectivity are also evident in resting-state functional connectivity MRI, an imaging technique that measures brain activity in subjects when they are not performing a specific task. Some of these differences appear to involve patterns of overconnectivity to different brain regions, explains Sathyanesan; other differences suggest that the cerebellums of patients with ASD don’t have enough connections to other brain regions.

These findings could clarify research from Children’s National and elsewhere that has shown that babies born prematurely often sustain cerebellar injuries due to multiple hits, including a lack of oxygen supplied by infants’ immature lungs, he adds. Besides having a sibling with ASD, premature birth is the most prevalent risk factor for an ASD diagnosis.

The review also notes that researchers have discovered structural changes in the cerebellums of patients with Down syndrome, who tend to have smaller cerebellar volumes than neurotypical individuals. Experimental models of this trisomy recapitulate this difference, along with abnormal connectivity to the cerebral cortex and other brain regions.

Although the cerebellum is a pivotal contributor toward these conditions, Sathyanesan says, learning more about this brain region helps make it an important target for treating these neurodevelopmental disorders. For example, he says, researchers are investigating whether problems with the cerebellum and abnormal connectivity could be lessened through a non-invasive form of brain stimulation called transcranial direct current stimulation or an invasive one known as deep brain stimulation. Similarly, a variety of existing pharmaceuticals or new ones in development could modify the cerebellum’s biochemistry and, consequently, its function.

“If we can rescue the cerebellum’s normal activity in these disorders, we may be able to alleviate the problems with cognition that pervade them all,” he says.

In addition to Sathyanesan and Senior Author Gallo, Children’s National study co-authors include Joseph Scafidi, D.O., neonatal neurologist; Joy Zhou and Roy V. Sillitoe, Baylor College of Medicine; and Detlef H. Heck, of University of Tennessee Health Science Center.

Financial support for research described in this post was provided by the National Institute of Neurological Disorders and Stroke under grant numbers 5R01NS099461, R01NS089664, R01NS100874, R01NS105138 and R37NS109478; the Hamill Foundation; the Baylor College of Medicine Intellectual and Developmental Disabilities Research Center under grant number U54HD083092; the University of Tennessee Health Science Center (UTHSC) Neuroscience Institute; the UTHSC Cornet Award; the National Institute of Mental Health under grant number R01MH112143; and the District of Columbia Intellectual and Developmental Disabilities Research Center under grant number U54 HD090257.

Eugene Hwang

Unexpected heterogeneity in CNS-PNET patients treated as a single entity

Eugene Hwang

“We found that some patients diagnosed with standard tools underwent much more treatment than necessary or intended,” said Eugene Hwang, M.D.

Eugene I. Hwang, M.D., a neuro-oncologist in the Center for Cancer and Blood Disorders, and other researchers at Children’s National Health System, Seattle Children’s Hospital and Research Institute, the Fred Hutchinson Cancer Research Center and the Hopp-Children’s Cancer Center at the NCT Heidelberg recently published the results of a clinical trial focusing on children with histologically diagnosed supratentorial primitive neuroectodermal tumors (CNS-PNET) and pineblastomas (PBLs).

The clinical trial, published online October 17, 2018 in the Journal of Clinical Oncology, included children and adolescents aged 3-22 with these brain cancers who were randomly assigned to receive carboplatin during radiation and/or isotretinoin after the standard intensive therapy (high-dose craniospinal radiation and months of inpatient chemotherapy).  Importantly, because each patient was treated prospectively according to the clinical trial design, the conclusions related to tumor biology were felt to be less affected by varied treatment plans.

“This trial really highlighted the importance of new molecular testing methods in accurately diagnosing some of the brain cancers included in the trial. We found that some patients diagnosed with standard tools underwent much more treatment than necessary or intended.” says Dr. Hwang. “Kids who aren’t receiving the right form of cancer treatment may not get better despite months and months of intensive treatment.”

During this clinical trial, 85 participants with institutionally-diagnosed CNS-PNETs/PBLs were enrolled. Out of the 60 patients with sufficient tissue, 31 were non-pineal in location, 22 of which represented tumors that did not fit in the diagnoses intended for trial inclusion.

The researchers discovered that patient outcomes across each molecularly-diagnosed tumor type were strikingly different. Patients with molecularly-confirmed supratentorial embryonal tumors/PBLs exhibited a five-year event free survival (EFS) and an overall survival rate of 62 percent and 78.5 percent, respectively. However, patients with molecularly-classified high-grade gliomas (HGGs) had a five-year EFS of 5.6 percent and OS of 12 percent, showing no benefit even with the chemotherapy and craniospinal radiation.

Researchers determined that for patients with CNS-PNETs/PBLs, prognosis is considerably better than previously assumed when molecularly-confirmed HGG are removed. Dr. Hwang and co-authors concluded that molecular diagnosis can greatly aid standard pathological diagnostic tools, preventing unnecessary intensive therapy for some patients while enabling more rational treatment for others.

“The findings from our clinical trial have highlighted the immense challenges of histology-based diagnosis for some types of pediatric brain tumors, and the enormous importance this has for children with brain cancer,” Dr. Hwang says. “We hope that ultimately our study will pave the way for molecular profiling to become a standard component of initial diagnosis.”

Yanxin Pei awarded St. Baldrick’s Foundation Research Grant for Childhood Cancer

Yanxin Pei, Ph.D., assistant professor at the Children’s Research Institute, was a recipient of a $100,000 grant that is being named the “Benicio Martinez Fund for Pediatric Cancer Research Grant” from the St. Baldrick’s Foundation, the largest private funder of childhood cancer research grants in the United States.

Dr. Pei studies medulloblastoma – one of the most common malignant brain tumors in children – and has identified a subpopulation of tumor cells that contribute to metastasis after radiotherapy. Her lab is now determining whether targeting these cells can eliminate or prevent the spread of medulloblastoma, thereby improving the outcome of patients with this disease.

In their latest round of funding, the St. Baldrick’s Foundation awarded 76 grants totaling more than $19.1 million to support physician-scientists studying innovative treatment options in the pediatric cancer space. The grants from St. Baldrick’s deliver on its commitment to support the most promising childhood cancer research and work to provide the best solutions possible for kids. The next St. Baldrick’s grant cycle will be announced in fall 2018.

“At St. Baldrick’s, we focus on funding research that has the best potential of giving kids the healthy childhoods they deserve,” said Kathleen Ruddy, CEO of the St. Baldrick’s Foundation.  “I’m proud to say that we have now funded more than a quarter billion dollars since 2005 to support lifesaving childhood cancer research.

Research and Education Week awardees embody the diverse power of innovation

cnmc-research-education-week

“Diversity powers innovation” was brought to life at Children’s National April 16 to 20, 2018, during the eighth annual Research and Education Week. Children’s faculty were honored as President’s Award winners and for exhibiting outstanding mentorship, while more than 360 scientific poster presentations were displayed throughout the Main Atrium.

Two clinical researchers received Mentorship Awards for excellence in fostering the development of junior faculty. Lauren Kenworthy, Ph.D received the award for Translational Science and Murray M. Pollack, M.D., M.B.A., was recognized in the Clinical Science category as part of Children’s National Health System’s Research and Education Week 2018.

Dr. Kenworthy has devoted her career to improving the lives of people on the autism spectrum and was cited by former mentees as an inspirational and tireless counselor. Her mentorship led to promising new lines of research investigating methods for engaging culturally diverse families in autism studies, as well as the impact of dual language exposure on cognition in autism.

Meanwhile, Dr. Pollack was honored for his enduring focus on motivating early-career professionals to investigate outcomes in pediatric critical care, emergency medicine and neonatology. Dr. Pollack is one of the founders of the Collaborative Pediatric Critical Care Research Network. He developed PRISM 1 and 2, which has revolutionized pediatric intensive care by providing a methodology to predict mortality and outcome using standardly collected clinical data. Mentees credit Dr. Pollack with helping them develop critical thinking skills and encouraging them to address creativity and focus in their research agenda.

In addition to the Mentorship and President’s Awards, 34 other Children’s National faculty, residents, interns and research staff were among the winners of Poster Presentation awards. The event is a celebration of the commitment to improving pediatric health in the form of education, research, scholarship and innovation that occurs every day at Children’s National.

Children’s Research Institute (CRI) served as host for the week’s events to showcase the breadth of research and education programs occurring within the entire health system, along with the rich demographic and cultural origins of the teams that make up Children’s National. The lineup of events included scientific poster presentations, as well as a full slate of guest lectures, educational workshops and panel discussions.

“It’s critical that we provide pathways for young people of all backgrounds to pursue careers in science and medicine,” says Vittorio Gallo, Ph.D., Children’s chief research officer and CRI’s scientific director. “In an accelerated global research and health care environment, internationalization of innovation requires an understanding of cultural diversity and inclusion of different mindsets and broader spectrums of perspectives and expertise from a wide range of networks,” Gallo adds.

“Here at Children’s National we want our current and future clinician-researchers to reflect the patients we serve, which is why our emphasis this year was on harnessing diversity and inclusion as tools to power innovation,” says Mark L. Batshaw, M.D., physician-in-chief and chief academic officer of Children’s National.

“Research and Education Week 2018 presented a perfect opportunity to celebrate the work of our diverse research, education and care teams, who have come together to find innovative solutions by working with local, national and international partners. This event highlights the ingenuity and inspiration that our researchers contribute to our mission of healing children,” Dr. Batshaw concludes.

Awards for the best posters were distributed according to the following categories:

  • Basic and translational science
  • Quality and performance improvement
  • Clinical research
  • Community-based research and
  • Education, training and program development.

Each winner illustrated promising advances in the development of new therapies, diagnostics and medical devices.

Diversity powers innovation: Denice Cora-Bramble, M.D., MBA
Diversity powers innovation: Vittorio Gallo, Ph.D.
Diversity powers innovation: Mark L. Batshaw, M.D.