Upregulation of Fas/Fas ligand-mediated apoptosis by gossypol in an immortalized human alveolar lung cancer cell line.
Gossypol has wide antineoplastic effects in vitro, but its effects on human lung cancer have not been explored. To evaluate the activity of gossypol against alveolar cell lung cancer and to provide information on the mechanism of action, we examined the effects of gossypol on the proliferation of A549 cells indirectly using an XTT assay and on the distribution of cells within the phases of the cell cycle using flow cytometry. We also examined several factors that may affect apoptosis, including p53, p21/WAF1, Fas receptor, Fas ligand (FasL) and caspase 8 activity. The results showed that gossypol inhibited proliferation of A549 cells at a concentration of 0.5 micromol/L after 12 h treatment. The effect was both dose- and time-dependent by the induction of apoptosis without the effect of p53 and p21/WAF1. Upregulation of Fas/FasL, in association with the activation of downstream caspase 8 activity, was observed following treatment with gossypol. The Fas/FasL pathway accounted for 75% of gossypol-mediated apoptosis. We suggest that the Fas/FasL apoptotic system is the major pathway for gossypol-mediated apoptosis of A549 cells. Gossypol had no effect on the distribution of A549 cells within the phases of the cell cycle. In conclusion, gossypol inhibited A549 cells mainly by induction of the Fas/FasL apoptotic pathway, but not the p53 and p21/WAF1 pathway.
Chang
Jung-San
JS
Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical Univeristy, Kaohsiung, Taiwan.
Hsu
Ya-Ling
YL
Kuo
Po-Lin
PL
Chiang
Lien-Chai
LC
Lin
Chun-Ching
CC
D017209:Apoptosis / Q000187:drug effects*; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism* / Q000473:pathology; D053181:Caspase 8; D020169:Caspases / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000494:pharmacology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D050759:Cyclin-Dependent Kinase Inhibitor p21; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D053222:Fas Ligand Protein; D016158:Genes, p53 / Q000235:genetics; D006072:Gossypol / Q000494:pharmacology*; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D008562:Membrane Glycoproteins / Q000502:physiology*; D011650:Pulmonary Alveoli / Q000378:metabolism* / Q000473:pathology; D011956:Receptors, Cell Surface / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects*; D019014:fas Receptor / Q000502:physiology*
C493956:CDKN1A protein, human; D018797:Cell Cycle Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; D019014:fas Receptor; C505530:CASP8 protein, human; D053181:Caspase 8; D020169:Caspases; D006072:Gossypol