Peter S. Klein

Peter S. Klein is a Professor of Medicine (Hematology-Oncology) at the Perelman School of Medicine, University of Pennsylvania. He holds multiple leadership roles including Director of the Physician-Scientist Pathway in the Department of Medicine, Vice-chief for Research in Hematology-Oncology, and member of the Abramson Cancer Center and David Mahoney Institute of Neurological Sciences. Dr. Klein serves as an attending physician in the Division of Hematology-Oncology at the Hospital of the University of Pennsylvania and advises the MD/PhD program.

Dr. Klein received his B.A. in Biochemistry from Harvard College in 1980, followed by his M.D. and Ph.D. in Biological Chemistry from Johns Hopkins University School of Medicine in 1988.

Dr. Klein's research spans several interconnected areas focused on understanding fundamental biological processes and their implications for human disease. His laboratory investigates:

• Wnt signaling and chromatin modifications in early vertebrate development
• Regulation of hematopoietic and neural stem cell self-renewal
• Molecular mechanisms of lithium action in bipolar disorder
• Role of GSK-3 in stem cell biology and cancer

His work bridges developmental biology, stem cell research, and translational medicine, with particular emphasis on how basic molecular pathways can be targeted for therapeutic applications in cancer and neuropsychiatric disorders.

Analysis of Dr. Klein's recent publications reveals a consistent focus on Wnt signaling pathways, stem cell biology, and the therapeutic applications of GSK-3 inhibition. His research spans from fundamental developmental biology (studying Wnt signaling in Xenopus embryos) to translational applications in hematopoietic stem cell expansion and cancer therapeutics. A significant thread throughout his work is the investigation of lithium's mechanism of action through GSK-3 inhibition, connecting his basic research to clinical applications in bipolar disorder. His laboratory has made important contributions to understanding how chromatin architecture is modified by Wnt signaling, how GSK-3 regulates hematopoietic stem cell self-renewal, and the neural mechanisms underlying mood disorder treatments.

Dr. Klein leads an active research laboratory with multiple postdoctoral fellows, graduate students, and research specialists. His lab employs a diverse array of techniques including molecular analysis of chromatin structure, biochemical analysis of signaling pathways, mouse models, and ex vivo stem cell culture systems. He is actively involved in training the next generation of physician-scientists through his role as Director of the Physician-Scientist Pathway and as an MD/PhD program adviser.