Inhibition of fibroblast growth factor 2-induced apoptosis involves survivin expression, protein kinase C alpha activation and subcellular translocation of Smac in human small cell lung cancer cells.
To investigate the mechanism by which fibroblast growth factor 2 (FGF-2) inhibits apoptosis in the human small cell lung cancer cell line H446 subjected to serum starvation, apoptosis was evaluated by flow cytometry, Hoechst 33258 staining, caspase-3 activity, and DNA fragmentation. Survivin expression induced by FGF-2 and protein kinase C alpha (PKC alpha) translocation was detected by subcellular fractionation and Western blot analysis. In addition, FGF-2-induced release of Smac from mitochondria to the cytoplasm was analyzed by Western blotting and immunofluorescence. FGF-2 reduced apoptosis induced by serum starvation and up-regulated survivin expression in H446 cells in a dose-dependent and time-dependent manner, and inhibited caspase-3 activity. FGF-2 also inhibited the release of Smac from mitochondria to the cytoplasm induced by serum starvation and increased PKC alpha translocation from the cytoplasm to the cell membrane. In addition, PKC inhibitor inhibited the expression of survivin. FGF-2 up-regulates the expression of survivin protein in H446 cells and blocks the release of Smac from mitochondria to the cytoplasm. PKC alpha regulated FGF-2-induced survivin expression. Thus, survivin, Smac, and PKC alpha might play important roles in the inhibition of apoptosis by FGF-2 in human small cell lung cancer cells.
Xiao
Desheng
D
Department of Pathology, Xiangya School of Medicine, Central South University, Changsha 410013, China.
Wang
Kuansong
K
Zhou
Jianhua
J
Cao
Huiqiu
H
Deng
Zhenghao
Z
Hu
Yongbin
Y
Qu
Xiahui
X
Wen
Jifang
J
D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D018288:Carcinoma, Small Cell / Q000378:metabolism* / Q000473:pathology; D002460:Cell Line; D045744:Cell Line, Tumor; D004789:Enzyme Activation; D016222:Fibroblast Growth Factor 2 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism*; D051571:Protein Kinase C-alpha / Q000378:metabolism*; D021381:Protein Transport; D015398:Signal Transduction; D013347:Subcellular Fractions / Q000378:metabolism; D000077022:Survivin
D051017:Apoptosis Regulatory Proteins; C107489:BIRC5 protein, human; C412403:DIABLO protein, human; D051034:Inhibitor of Apoptosis Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008869:Microtubule-Associated Proteins; D024101:Mitochondrial Proteins; D009363:Neoplasm Proteins; D000077022:Survivin; D016222:Fibroblast Growth Factor 2; D051571:Protein Kinase C-alpha