Title: Lung-tumorigenic effects of air pollutant fine particulate matter via 15-lipoxygenase metabolites

Biography:

George G Chen is a professor in the Department of Surgery, Faculty of Medicine, the Chinese University of Hong Kong, China.  He has extensive experience in cancer research. He has authored or co-authored more than 210 papers and has written a number of books or book chapters, with Web of Science Core Collection h-index: 33 and Google Scholar h-index: 41.

Abstract

Air pollution is a major environmental risk to health and causes various diseases, especially respiratory diseases. Though epidemiological studies have clearly shown the connection between air pollutant fine particulate matter (PM2.5) and lung cancer, the mechanism of its tumorigenetic effects remains largely unknown. To this end, in this study we compared the lung tumorigenetic effects of PM2.5 with smoking carcinogen NNK on 15-lipoxygenases (15-LOXs), the enzymes that were previously demonstrated to involved in NNK-induced lung cancer.  It was found that PM2.5 and NNK worked in a very similar way to inhibit 15-LOXs, reducing their metabolites, 15S-HETE and 13S-HODE. The change in 15-LOX metabolites led to stimulate lung cell proliferation, migration, and invasion, and cancer stem cell formation in the cultured lung cells. In vivo study further confirmed that the tumor formation rate and tumor growth was significantly higher/faster in mice receiving PM2.5 or NNK, along with a significant reduction in expression of 15-LOX proteins as well as their metabolites. We concluded that PM2.5 was experimentally a lung-tumorigen and it worked in a way similar to smoking carcinogen NNK to cause lung tumorigenesis via reducing 15-LOX metabolites. (M-Y Li, CSH Ng, Y Liu, AWY Kong, R Ho, E Chak, HL Qi, J Hao, IYP Wan, T Mok, MJ Underwood contributed to this work).