Environmental Health Sciences

For over a century since the discovery of X-rays by Röentgen, students in radiological sciences have been taught that the quintessential target for radiation induced genetic damages resides in the DNA of the nucleus. Using a precision charged particle microbeam, Dr. Tom K. Hei and his group show that targeted cytoplasmic irradiation can result in mutation in the nucleus of the hit cells. This extranuclear effect, widely reported by the press, sets the stage for another important contribution made by Dr. Hei’s laboratory on the non-targeted (extracellular) effect of ionizing radiation. Together these results lead to a paradigm shift in our understanding of the target theory and other basic radiobiological principles and foster the emergence of a new discipline on bystander effects in the radiation biology field.

Dr. Hei is also internationally recognized for his expertise in the asbestos and fiber toxicology field. His asbestos research program, funded continuously by the National Institute of Environmental Health Sciences for more than 15 years, has made major contributions in our understanding of the basic molecular mechanism of how asbestos induces cancer through the induction of large gene and chromosomal mutations via the production of reactive radical species. Dr. Hei has served on various advisory panels commissioned by the Institute of Medicine of the National Academy of Sciences and the Environmental Protection Agency. His work has been highlighted several times in the Research Brief of the Superfund Basic Research Program.

A third area of interest of Dr. Hei’s research portfolios is the identification of the tumor suppressor function of the BigH3 (TGFβ1) gene which encoded a secreted protein that plays an important function in cellular adhesion and migration. This gene has recently been shown to be down-regulated or have loss of function in human prostate, lung and breast cancers. Reintroduction of this gene into these cancer cell lines through retroviral infection suppresses the tumorigenic phenotype. Translational studies in the possible utilization of the gene product as a biomarker for tumor diagnosis is currently underway.

Dr. Hei received his B.Sc. (Summa Cum Laude) from the University of Wisconsin-Whitewater and his Ph.D. in experimental pathology from Case Western Reserve University. He has been on the faculty of Columbia University since 1983 and is currently Professor of Environmental Health Sciences in the Mailman School of Public Health and Deputy Director of the NIEHS Center for Environmental Health in Northern Manhattan. Dr. Hei’s primary appointment is Professor and Vice-Chairman of Research in Radiation Oncology and the Associate Director of the Center for Radiological Research in the College of Physicians and Surgeons. Dr. Hei has several adjunct professorships in both China and Japan.