James E. Trosko

James E.  Trosko
  • Professor Emeritus, Department of Pediatrics and Human Development


The Trosko lab focused on the mechanisms of carcinogenesis and mutagenesis. His initial research involved the study of radiation-induced mammalian mutagenesis. This led to the discovery of deoxyribonucleic acid (DNA) repair in normal human cells and the lack of DNA repair and increased mutagenesis in the cancer-prone xeroderma pigmentosum syndrome. Later work with the tumor promoter, phorbolester, he discovered that the inhibition by tumor-promoting chemicals, oncogenes and growth factors were related to the mechanism of tumor promotion by their shared ability to modulate gap junction function. His team then developed several in vitro assays to detect chemical modulators of gap junctional intercellular communication (GJIC) (e.g., metabolic cooperation assays; fluorescent recovery after photobleaching; scrape loading dye transfer, etc.) Later they found that modulation of GJIC was related to chemical induced teratogenesis, reproductive dysfunction and neurotoxicity. Most recently, his group demonstrated that normal human epithelial stem cells could be isolated from kidney tissues and breast tissues. In addition, anti-tumor chemicals, as well as tumor suppressor genes appear to up-regulate GJIC in a manner opposite to tumor promoters and oncogenes. He has recently discovered biomarkers for adult human stem cells that has provided strong evidence for the "stem cell theory" of cancer.


Central Michigan Univ., B.A., 1960, Chemical Biology  
Michigan State Univ., M.S., 1962, Genetics  
Michigan State Univ., Ph.D., 1963, Radiation Genetics 





Dr. Trosko at PubMed