活化p38 MAPK激酶調控阿黴素誘發CL3 肺癌細胞凋亡之研究

• Main Authors: Wu, Jen Chieh, 吳仁傑
• Other Authors: Yang, Jia-Ling
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/11356465790139468543

碩士 === 國立清華大學 === 生物科技研究所 === 98 === Doxorubicin, also called adriamycin, is a widely used therapeutic agent in lung cancer. However, the development of drug resistance is a major problem for clinical applications of doxorubicin. Activation of the p38 mitogen-activated protein kinase (MAPK) has been reported to contribute to survival or apoptosis following doxorubicin treatment. To gain insight into the role of p38 MAPK in doxorubicin sensitivity, we explore this issue in a non-small cell lung cancer cell line, CL3. We found that doxorubicin dose- and time-dependently induces cell death by using MTT assay. Doxorubicin transiently activates the p38 MAPK signaling as measured by immunoblotting. Co-administering SB202190, a 38 MAPK inhibitor, markedly enhanced the doxorubicin-induced cytotoxicity. Using a flow cytometry-based methodology, we found that SB202190 significantly increased the doxorubicin-induced apoptosis. Depleting α or β isoforms of p38 MAPK by transfection of specific small interfering RNAs (si-p38α/β) also augmented the apoptosis caused by doxorubicin. SB202190 co-treatment or introducing si-p38α/β could enhance the doxorubicin-induced caspase-3 activation. Doxorubicin increased the protein levels of anti-apoptotic Bcl-2 and apoptotic Bim, and SB202190 co-treatment markedly reduced the former but not the later. Doxorubicin also induced the amounts of phospho-Bcl-2(Ser70) that could only be slightly decreased by SB202190. The down-regulation of doxorubicin-induced Bcl-2 by SB202190 co-treament was verified in the mitochondrial fraction. Together, this study suggests that p38 MAPK activation is necessary for the increased mitochondrial Bcl-2, which may involve Ser70 phosphorylation, thereby supporting CL3 lung cancer cells to against apoptosis following doxorubicin.