Petritsch Lab Team

Claudia K. Petritsch, Ph.D

Dr. Petritsch is an Associate Professor in Research at the Department of Neurosurgery, affiliated faculty member at the Wu Tsai Neurosciences Institute and the Stanford Bio-X program. She directs the Petritsch research team and the fresh tissue collection core in Neurosurgery.

Claudia earned her PhD (Dr. rer.nat) at the Institute for Molecular Pathology (IMP) in Vienna, where she trained in cancer signaling, and conducted postdoctoral studies on neural stem cells and asymmetric cell division in the Lab of Dr. Yuh Nung Jan at the Howard Hughes Medical Institute and University of San Francisco, California. After two years as an instructor and head of a research team in Munich, Germany, Dr. Petritsch returned to UCSF to conduct research in oligodendrocyte progenitor cells, angiogenesis and immune regulation in glioma. Dr. Petritsch is an expert in brain stem and progenitor and glioma biology, in vitro and in vivo model development and tumor-immune interactions. Her research identified conserved mechanisms of cell fate determination in mammalian brain progenitors and led to a paradigm shift in understanding how brain progenitor cells self-renew and differentiate. She guided the generation and distribution of several immune competent mouse models for studies of the glioma immune microenvironment.


Lab Managers

Yoko Hirata, M.Sc

Yoko earned her M.Sc in cell biology at Yamaguchi University, Japan. Yoko manages the development, maintenance and analysis of our in vivo models. She is also responsible for chemical and biological safety and welcoming and orienting new team members. Before joining the team in February 2019, Yoko interned at the Gladstone Institute. Yoko is particularly interested in studying intra-tumoral cellular heterogeneity in pediatric malignant gliomas resistant to molecular targeted therapies.

In her free time, Yoko enjoys embroidery and listening to music, especially smooth jazz. Sometimes she goes to Blue Note Napa with her daughters.


Postdoctoral Scholars

Alim Basaran, MD, PhD

Alim studied medicine, mathematics, physics, and computer science at the University of Innsbruck, Austria. He did a PhD in Neuroimaging with Prof. Rupert Lanzenberger and the proteomic and mass spectrometry group of Prof. Dr. Ruth Gruenberger at the University of Vienna. He joined the Medical University in Augsburg Germany for his residency in neurosurgery and is currently taking a break to pursue research. He has 6 original publications and one review from this previous work. In the Petritsch lab, Alim participates in generating patient-derived cell lines and xenograft models and utilizes them to optimize and personalize treatment for patients with brain cancer. Alim has several projects and is particularly excited about identifying novel therapies for recurrent and therapy-resistant glioma and rare brain metastases. He interrogates expression programs in heterogenous tumor cells, including cancer stem cells, to identify the mechanisms for therapy resistance and  immune suppression. To overcome therapy resistance, he is searching for novel combination therapies that extend survival in preclinical models and he is investigating the underlying causes for treatment success. He is also very passionate about generating high-fidelity models for rare brain metastases using patient-derived materials and 3D spheroid cultures for preclinical trials.

Keywords: patient-derived models, novel therapeutics, cancer stem cells, CRISPR/Cas9 genome editing (in vitro and in vivo)

Collaborators: The Treehaus Inivitative at UCSC headed by Dr. Olena Vaske; Lab of Dr. Marius Wernig (Stanford),

Fun Fact: Alim performed with the big Saz (a traditional string instrument) at turkish weddings, while studying physics and medicine, he reads ancient philosophy, and loves thinking about the infinity of the universe

Azad Cheko, MD, PhD

Azad earned his MD from Johannes Gutenberg University in Mainz, Germany. He became a German board-certified neurosurgeon in November 2020. He completed his Doctoral Thesis at the University Hospital of Marburg, Germany. During that time, he researched how the ingestion of statins before an infarct event is associated with the development and treatment outcome of a SIRS (Systemic Inflammatory Response Syndrome) in patients with supratentorial space-occupying cerebral infarction. During his last year of university, he also researched the role of various protein-coding genes in the development of vestibular schwannoma. Apart from being very active surgically, his time in the lab has been very enriching and he will now continue his scientific research by collaborating on understanding the biology of brain metastases and on finding solutions in the treatment of these tumors by combining basic and clinical scientific research. His goals are centered around fixed tissue analyses and model development and he compiles patient-matched primary cancer-brain metastases tissues for generating tissue microarrays and gene expression profiling using nanoString nCounter technology. Using these approaches, he characterizes features such as invasiveness, vascular co-option, proliferation, stemness and cell-type heterogeneity. With TMAs he specifically analyze sthe immune landscapes, including the frequency and activities of microglia, tumor-associated macrophages (TAMs) and myeloid derived suppressor cells (MDSCs). His second project is to centrally generate and validate clinically relevant, experimental syngeneis and xenograft models for brain metastases. These are critical tools to validate molecular data derived from primary patient material and for functional and preclinical testing and grafting at different locations to identify metastatic seed cells and characterize them by next generation sequencing.


Fun Fact: He wanted to be a fighter pilot as a kid.

Jongwhi Park, M.Sc, Ph.D.

Jongwhi Park received his Ph.D in Neuroscience from Medical University of Innsbruck, Austria in 09/2018. He examined the functional role of an endogenous inhibitor of receptor tyrosine kinase signaling in brain tumor, glioblastoma using analyses of publically available databases and in vivo tumorigenicity tests. Prior to that, he obtained an M.Sc from Friedrich Alexander University Erlangen-Nürnberg, Germany after completing his B.Sc from Korea University, Seoul, Republic of Korea. His current research is focused on understanding the tumor microenvironment and the mechanisms of malignant progression in low-grade glioma for more effective and targeted therapies.


Jolien Pas, PhD

Jolien received her PhD in Organic Bioelectronics from the Ecole des Mines de Sainte Etienne in France. She focused on the development of flexible, micro-scaled devices to improve the electrophysiological read-out from the brain for both in vitro and in vivo applications. After 4 years working in a medical device spin-off, Panaxium, she decided to continue her academic career and joined the Petritsch lab at Stanford as of mid October 2021. 

She is interested in how brain cancer, more specifically BRAF mutated gliomas, originates and evolves in time and focusses on the evaluation of multiple combination therapies to kill both stem-like and progenitor-like tumor cells using patient-derived glioma models. She is also interested the mechanisms behind tumor growth and aims to study (a)symmetric cell division using custom-made microfluidic devices and next generation sequencing. 


In her spare time, she loves going crazy on her road bike and hiking in the mountains. Her travels through Australia and South America were trips never to forget. She enjoys cooking and testing out new recipes, besides exploring culinary specialties from all over the world during her travels.”

Fun Fact: She traveled almost the entire length of the Andes.


Emon Nasajpour, BSc, MD candidate

Emon is a third-year medical student at the Florida State University College of Medicine who had dreams of pursuing a career as a researcher and neurosurgeon or neurologist as far back as he can remember. He previously worked with Dr. Michael Waters at the University of Florida conducting research on SCA-13. He was a caretaker for a woman with Alzheimer’s Disease in New York City and helped her adhere to a protocol developed by Dr. Dale Bredesen at UCLA. This experience has further shaped his interest in neurological diseases. After completing two years of medical school, and various roles, he built interests in various specialties of medicine and is now taking a year off from medical school to conduct research in the Petritsch Laboratory. In the Petritsch lab, Emon coordinates the patient-derived model development, and he spends his days often interrogating and assembling patient-databases, surgical schedules, and enjoys communicating with neurosurgeons, the OR staff, picking up tissue from the OR, processing it for cell culture and xenograft development. He conducts research in collaboration with the UC Santa Cruz group identifying gene outliers in the RNA expression profile of patients with brain tumors undergoing surgery and treatment at Stanford. He validates the drug sensitivities in patient-matched and -derived tumor cells from and looks for novel therapeutic approaches to prevent tumor recurrence and overcome therapy resistance. Over the next few months, he will extend this approach to more patients, and envisions completing a full bedside-to bench-to bedside circle by gathering sufficient in vitro and in vivo data (in mouse models) to make personalized treatment recommendations for children with brain tumors who are not responding to standard of care.

Collaborators: The Treehaus Inivitative at UCSC headed by Dr. Olena Vaske; Drs. Grant, Mahaney, Hong, and Prolo (pediatric neurosurgery);

Fun Fact: Emon plays competitive table tennis, and breeds and shows South African Boer Goats with his Dad.

Samrat Thapa
Undergraduate Researcher

Samrat is a freshman at Stanford hoping to major in Biomedical Computation. His primary interests are in stem cells, specifically the mechanisms by which normal stem cells become cancerous. With a background studying hematopoietic stem cells and computational methods, he hopes to approach medicine with perspectives of CS and developmental biology. Beyond research, Samrat is fascinated with rockets, taking part in the Stanford Space Initiative Rocket team, volunteers with Discovering Science Together, a Stanford run initiative to teach science to underprivileged elementary/middle school students in the bay area, and enjoys long distance running; he joins the Petritsch Lab through the Wu Tsai funded summer NEURO program. 


Caitlynn To-Duyen Tran
Undergraduate Researcher

Caitlynn is a first-year undergrad at Stanford University who is planning on majoring in Chemistry. She joined the Petritsch Lab in Fall 2021 in hopes to get involved with the patient derived cell lines. Having done research in medicinal chemistry and drug design, she is interested in exploring a more clinical approach to treatment and working with different therapeutics this coming year. In addition to research, Caitlynn enjoys dancing in various styles, whether that be recreationally or competitively. She is also involved with Science Olympiad through coaching junior high school students and organizing a local tournament for high school students to compete. 


Ameera Waterford
Undergraduate Researcher

Ameera is a first-year undergrad at Stanford who grew up in Maui, Hawaii. She joined the Petritsch Lab in Spring 2021 as a Bio-X fellow and will assist with projects analyzing treatment effects on tumor cell heterogeneity. In the summer, she will help implement a third method of tumor-cell analysis using organotypic slice cultures. She will also assist in database creation, organization, and maintenance. 

In her spare time, she enjoys hiking in scenic places, snorkeling at the beach (yes, she has seen a shark--yes, she made it out alive), baking moderately unhealthy but extremely delicious foods, binge-watching Criminal Minds as well as any show on TLC, and playing basketball. Post-pandemic she would like to travel the world, but for now she is content just exploring Stanford's beautiful campus.


Postdoctoral scholars

2019-2021 Anne Marie Barrette (Scientist, TrueBinding)


Former students

2019 Alex Washburn (Bowdoin College)

Natalie Pedicino (graduate program UCSC)

Alexa Gwyn (Vassar)