Effects of Benzo[a]pyrene on cell cycle in human lung adenocarcinoma CL-3 and A427 cells

• Main Authors: Yng-Tay Chen, 陳瀅太
• Other Authors: Huei Lee, Ph. D.
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/60323061381496935679

碩士 === 中山醫學院 === 毒理學研究所 === 87 === Benzo[a]pyrene (B[a]P) is a well known carcinogenic polycyclic aromatic hydrocarbons which are widely distributed in airborne particulate. Our previous studies have indicated that high DNA adduct levels were found in lung adenocarcinoma CL-3 cells induced by B[a]P compared with that of lung adenocarcinoma A427 cells. In order to understand why different human lung cancer cells have different DNA damages induced by B[a]P, the cell cycle and different proteins involved in the cell cycle control, such as p53, p21, MDM2, and cyclin B1 were evaluated by flow cytometry and Western blot, respectively. The flow cytometry data indicated that G2/M arrest was observed in CL-3 cells treated by 10 mM B[a]P, whereas the proportion of S phase cell was decreased. However, the G1 phase of CL-3 cells were not changed after treatment of B[a]P. On the other hands, the cell cycle of A427 cells was not changed when the cells were treated with 1 mM or 10 mM of B[a]P. In Western blot analysis, we found that similar p53 protein expressions during 1 - 4 hr were revealed in CL-3 cells treated by B[a]P. The G2/M peak was observed in the period. This result suggested that p53 was not involved in G2/M arrest of CL-3 cells treated by 10 mM B[a]P. In the period, p21 protein was almost not detected by Western blot, However, cyclin B1 protein levels were consistent with the change of G2/M arrest. From the above data, we conclude that the human adenocarcinoma CL-3 cells treated with 10 mM B[a]P have G2/M arrest which was independent with p53 pathway.