NF Research, Remotely
Most all solid cancers are composed of both neoplastic (cancerous) and non-neoplastic (stromal) cells that interact in a tightly orchestrated manner to dictate brain tumor development and progression. Over the past fifteen years, our laboratory has been interested in how the pediatric low-grade glioma ecosystem is assembled and regulated relevant to brain tumor formation and growth. Current studies in the Gutmann Lab use a multitude of different approaches to understand this complex microenvironment, ranging from bioinformatic deconvolution strategies (Olivia Cobb) and immune cell population phenotyping (Jit Chatterjee) to single cell RNA sequencing and genetically engineered mouse modeling (Amanda Costa). Collectively, these investigations aim to initially define the cells and molecular signals that establish and maintain this ecosystem, and subsequently interrupt the responsible circuitry as potential approaches for treating pediatric brain tumors.
Children with NF1 often have cognitive and behavioral delays, including learning disabilities, attention deficit, and autism spectrum disorder. While mouse models are useful for studying these neurobehavioral problems, they often do not faithfully capture some of the unique features of the developing human brain. Over the past ten years, our laboratory has used human induced pluripotent stem cells (hiPSCs) to investigate the impact of NF1 gene mutations on human nerve cell function and brain development. These hiPSCs come from skin, urine or blood samples donated by people with NF1, and can be reprogrammed into nearly every type of cell in the body. Using NF1-patient hiPSCs, pioneering work by Dr. Corina Anastasaki and MD-PhD student, Michelle Wegscheid, has revealed new neuronal abnormalities in isolated human brain nerve cells and human mini-brain tissues (cerebral organoids). In addition, Michelle Wegscheid and Kelly Hartigan have leveraged these humanized models to identify new genes important for brain development and autism. Since little is known about how the NF1 protein (neurofibromin) controls nerve cell biology, Dr. Anastasaki has created novel human and mouse reagents to identify neurofibromin-interacting proteins and discover the mechanisms underlying NF1-mutant neuron dysfunction. Lastly, we have also employed hiPSCs, in combination with Nf1-mutant mice, to study the role of sex and NF1 mutation in specifying the function of neurons (Dr. Anastasaki) and microglia (in collaboration with Professor Helmut Kettenmann, Max Delbruck Center, Berlin).
People with Neurofibromatosis type 1 (NF1) are prone to the development of tumors associated with nerves, including brain tumors and peripheral nerve sheath tumors (neurofibromas). The intimate association between tumors and nerves in the setting of NF1 raises the intriguing possibility that nerves (neurons) are important drivers of tumor formation and growth. Over the past five years, we have been attacking this question in several different ways. The first involves a collaborative project with Dr. Michelle Monje (Stanford University), now spearheaded by our former postdoctoral fellows, Dr. Yuan Pan. In this project, we are investigating the idea that neuronal activity induced by light controls Nf1 optic glioma formation and growth in mice. The second project is focused on determining whether NF1 mutation endows sensory neurons with the ability to stimulate peripheral nerve sheath tumor (neurofibroma) growth. These exciting studies are led by Dr. Corina Anastasaki and Jason Papke, using human induced pluripotent stem cell models. The third project builds on findings initially made by Dr. Xiaofan (Gary) Guo last year, in which he showed that NF1-mutant mouse and human neurons activate T cells to increase Nf1 optic glioma growth. Understanding how NF1 mutation in neurons changes T cell-microglia interactions relevant to tumor formation and progression is important for dissecting the “neuron-immune cell-cancer axis” operative in brain and nerve tumors.
While the brain was previously thought to be isolated from infiltrating immune system cells, we now appreciate that one type of white blood cell, the T lymphocyte, normally traffics through the brain and interacts with numerous brain cells, including astrocytes and microglia. Over the past six years, we have been studying how T lymphocytes (T cells) are attracted to brain tumors, how they are activated, and what their activation means for cancer cells. We now know, based on the outstanding work of Drs. Yi-Hsien Chen, Yuan Pan, and Xiaofan (Gary) Guo in our lab, that brain tumor cells secrete chemokines that attract T cells, and that T cells stimulate microglia to produce growth factors required for low-grade brain tumor (optic glioma) formation and expansion. Current studies are focused on understanding how inflammatory conditions alter the ability of T cells to control optic glioma formation and growth (Dr. Jit Chatterjee), how T cells become activated in the brain, and how other factors, like sex and Nf1 gene mutation, change T cell function relevant to brain tumor formation. Understanding these cellular interactions may yield new therapeutic approaches for pediatric and adult brain cancers.
During the COVID-19 research ramp-down period, the Gutmann Lab has spent a lot of time in Zoom conferences and meetings discussing our current projects and planning our future scientific directions. Despite the fact that we could not be at the bench performing experiments the way we used to do, we have taken advantage of this period to craft a graphic representation of our laboratory research mission. As we begin to ramp up our laboratory research operations, we want to take the opportunity to share these ideas with you. Stay tuned each week for information about a different topic related to our laboratory scientific focus. As always, our goal is to define the environmental, genomic, genetic, cellular and molecular factors that underlie the development of the nervous system tumors and neurodevelopmental deficits seen in people with Neurofibromatosis (NF) and related medical conditions. We aim to continue to translate these research findings into precision medicine strategies for our families. Moreover, if any of these themes spark your interest, please reach out to me about potential training opportunities in the Gutmann Lab.
David H. Gutmann, MD, PhD, FAAN
I’m a rising second year medical student at Washington University who joined the Gutmann lab to work on cancer neuroscience. I’m specifically interested in the relationship between nerve cells (neurons) and cancer.
Since the COVID laboratory shutdown, I have been working with Dr. Corina Anastasaki, an Instructor in the Department of Neurology and Washington University NF Center, to study how mutations in the NF1 gene change the ability of neurons to control tumor growth. We have previously shown that neurons with NF1 gene mutations increase brain tumor growth through interactions with immune system cells. Beginning this summer, I’m eager to learn whether neurons can directly control the growth of nerve sheath tumors (neurofibromas) using human induced pluripotent stem cells. Better understanding this relationship could facilitate the design of alternative treatments for neurofibromas in people with NF1.
Karim Saoud, BS
I am a rising second year medical student at Washington University who joined the Gutmann laboratory to work on cancer biology. I am particularly interested in how immune system cells influence non-cancerous cells in the brain to control tumor development and growth. Although I only joined the laboratory a few months ago, Dr. Gutmann and the rest of the team have made me feel very welcome.
Since the COVID-19 pandemic laboratory shut-down, I have been working with Dr. Jit Chatterjee, a postdoctoral fellow in the laboratory, to determine whether allergic conditions, such as asthma, influence low-grade brain tumor (optic glioma) development in mice. We have previously shown that T cells in the blood enter the brain and stimulate microglia to produce growth factors that increase optic glioma growth.
I have also had the opportunity to delve into the scientific literature while working from home, learning about NF1, T cells, and microglia. When it is safe to return to the laboratory this summer, I hope to utilize the knowledge I’ve gained to build upon the work of Dr. Jit Chatterjee and other laboratory members to define the mechanisms by which inflammation changes the interactions between T cells and microglia relevant to Nf1 optic glioma formation and growth. Our ultimate goal is that these studies may help us devise alternative therapies to treat these brain tumors in children with NF1.
Elizabeth Cordell, BA
My name is Suzanne and I am one of the Staff Scientists in the Gutmann Lab. Since the COVID-19 pandemic laboratory shut-down, I have been responsible for the maintenance of our mouse colony. In addition, I have continued our essential long-term studies focused on identifying treatments to reduce vision loss in mice with optic gliomas. As we gradually increase our research activities, I will be returning to my work with the Gilbert Family Foundation Vision Restoration Initiative which is dedicated to the prevention of optic nerve damage and visual impairment caused by NF1.
Suzanne Scheaffer, MS
As a Staff Scientist in the Gutmann Lab, I maintain our collection of human induced pluripotent stem cell (hiPSC) lines, assist our diverse group of researchers with their projects, and manage general operations and safety for the team. Unfortunately, the COVID-19 induced shut-down forced our laboratory to greatly reduce the work we conducted as the world fought to control the growing spread of this new virus. During this time, I continued to work in the lab maintaining our cell lines, monitoring equipment, and ensuring our researchers had the tools and supplies they needed to work remotely or in the lab when required. I even had a go at making my own PPE to keep our team members safe using old NF Center t-shirts for face masks. Now as our community moves to reopen, I have been assisting our researchers with the ramp-up process, so that on their return, we may seamlessly resume our critical work seeking a greater understanding of neurofibromatosis.
Jason Papke, MS
Working remotely in style, complete with the absolutely necessary puppy-purse-head-gear, demanded by my 2-year-old.
I am an Instructor in the Department of Neurology. I have assumed a leadership role in Dr. Gutmann’s laboratory, spearheading many projects related to human induced pluripotent stem cells (hiPSCs) and precision medicine.
I am currently studying how we can best model the formation of patient low-grade brain gliomas in mice by combining our expertise in hiPSC technology and mouse brain tumor development. Before the COVID-19 pandemic, I was trying to define the conditions necessary for human low-grade glioma growth in the mouse brain.
Since the pandemic-mandated laboratory shut-down, I have focused on analyzing all my research findings and compiling them into a manuscript describing this new exciting experimental model. We hope that our work will help researchers around the world successfully and efficiently grow patient brain tumor samples in mice as an initial step towards developing better treatments for childhood brain tumors.
Corina Anastasaki, PhD
I am a postdoctoral fellow from Portugal who joined the Gutmann laboratory in February 2019. I am interested in brain tumor immunology, and have been leading several studies using Neurofibromatosis type 1 (NF1) mouse models of low-grade brain tumors, called optic gliomas. For these projects, I am leveraging numerous complementary methods, ranging from single cell RNA sequencing to complex bioinformatics, to define the different immune cell populations that interact and create the optic glioma microenvironment in mice.
When I started hearing from friends how alarming the COVID-19 pandemic situation was in Europe, I felt grateful to have time to prepare for this pandemic in the United States. Prior to the research laboratory ramp-down, I made immediate changes to my work schedule, focusing on generating large volumes of data that I could analyze remotely at home. I truly believe that this terrible situation has provided me with an opportunity to grow as a scientist and become more efficient. In addition to data analysis, I have also been using this time to become more proficient with the software tools we routinely use, as well as to write initial drafts of a manuscript describing my research findings.
Amanda Costa, PhD
I am a pediatric neuro-oncologist completing my postdoctoral research fellowship in the Gutmann laboratory. I am studying how several factors, including the germline Nf1 mutation and age, converge upon specific stem cells in the brain to influence mouse Nf1 optic glioma formation.
Since the COVID-19 pandemic laboratory shut-down, I have focused on writing my first major manuscript describing these exciting findings. These studies have established the groundwork for future studies evaluating how other risk factors, including other genetic mutations and environmental factors, act on stem cells in an age-defined manner to influence brain tumor formation in children.
Nicole Brossier, MD, PhD
I am a newly graduated staff biostatistician in the Gutmann laboratory studying informatic approaches to NF research using RNA-sequencing, statistical comparisons, cluster analysis and other methods.
Since the COVID-19 pandemic laboratory shut-down, I am grateful to have been taking on all kinds of new informatics-focused projects, including developing novel approaches to defining the different populations of cells in NF1 brain tumors from RNA-sequencing data. I am also very involved in several other studies, such as examining new mutations in NF1 patient samples and identifying novel genes in immune cells important for brain tumor formation. I am also using this time to help design new experiments with other trainees in the laboratory.
Olivia Cobb, MS, Bioinformatics Specialist
I am an MD/PhD trainee in the Gutmann laboratory studying how distinct NF1 gene mutations differentially contribute to the spectrum of brain developmental abnormalities seen in individuals with NF1. Specifically, I am using a three-dimensional, self-organizing model of human brain development (brain organoids or mini-brains) derived from patient induced pluripotent stem cells (iPSCs) to explore the effects of NF1 gene mutations on human brain development.
Since the COVID-19 pandemic laboratory shut-down, I have focused on analyzing data that I acquired from brain organoids harboring a specific type of NF1 mutation involving deletion of the NF1 gene and several other genes (NF1 microdeletion). Using a combination of fluorescence imaging, gene expression, and molecular signaling analyses, I am defining brain developmental abnormalities for this mutation type, and investigating the gene(s) responsible for those abnormalities.
In parallel, I have been working with Dr. Gutmann to draft a manuscript and doctoral dissertation describing my findings. By studying the pathophysiology of large genomic deletions involving NF1 in human brain organoids, I hope to advance our understanding of how NF1 regulates human brain development and identify mechanistic etiologies for the high burden of cognitive abnormalities seen in patients with NF1 gene deletions.
Michelle Wegscheid, MD/PhD trainee
I am Jit Chatterjee, a postdoctoral fellow in the Gutmann laboratory, studying how immune system cells, called T lymphocytes, control Nf1 optic glioma formation and growth. In addition, I am interested in understanding how allergic conditions impact on the risk of brain tumors in children. Using various approaches, I have been working to define the mechanisms by which T lymphocytes interact with other non-cancerous cells to create a microenvironment favorable for Nf1 optic glioma development.
During the COVID-19 pandemic, I have tried to complete some of the critical long-term experiments that I started prior to the shutdown. In addition, I have been working with Dr. Gutmann to submit my first grant application, as well as to assemble the experimental results for my first manuscripts as a postdoctoral research fellow. While I miss the laboratory, I have also been reading published papers from other research teams, which will provide me with additional ideas and directions I could pursue once I return to the bench.
Jit Chatterjee, PhD
We are living through unprecedented times as scientists and physicians. In the NF Center, we have shifted much of our clinical care of families with NF to telemedicine visits, and reduced laboratory operations to maintenance of critical resources.
While it may appear as though research has ground to a halt during the COVID-19 pandemic, we have continued to make progress in different ways, leveraging the creativity and adaptability of our talented scientists.
Over the next several weeks, you will read about some of this progress from members of our laboratory. I hope that you enjoy reading about their work and their commitment to NF. I could not be prouder of this amazing group of researchers.
David H. Gutmann, MD, PhD, FAAN