Development of Methods for Exposure of Cultured Cells to Direct and Secondhand Cigarette Smoke

Abstract

Several epidemiological studies have linked cigarette smoking to breast cancer, particularly in young women. However, there is no scientific validity of this link between either direct or secondhand smoking and breast cancer. Because of difficulties in conducting such studies in humans, it is necessary to develop a smoke exposure model system for cells in culture. We have developed and standardized a smoke exposure model system for human breast cell lines. This is a modified version of CULTEX cell culture smoke exposure system using the principle of the air/liquid exposure technique. Cells were grown in culture media (DMEM/F‐12) and exposed to both direct and secondhand smoke generated from 1R3F cigarettes in a THRI MS‐SS smoke exposure system. A sham control group was also used where cells were exposed to the same environmental condition without smoke exposure. For the dose response study breast cells were exposed to 0.03, 0.06, 0.12 and 0.18 puff/ml and incubated for 24 h. For time response study, cells were exposed to 0.18 puff/ml and then incubated for 6, 12, 24 and 36 h. Our results indicated that both direct and secondhand smoke exposure caused an increase in cell proliferation and a morphological change at low dose and cellular apoptosis at higher dose. (Supported by 2006 FAMRI Clinical Innovator Award).