Fatty acid synthase inhibitors cerulenin and C75 retard growth and induce caspase-dependent apoptosis in human melanoma A-375 cells.
Fatty acid synthase (FAS) has been shown previously to be highly expressed in breast and prostate carcinomas, but has low expression level in normal tissues. We also found in this study that FAS was expressed in a number of cancer cell lines of different histotypes. The growth-inhibitory effects of FAS inhibitors cerulenin and C75 were then investigated on these cancer cell lines, particularly the human melanoma A-375. MTT assay revealed that the cancer cell proliferation and viability was reduced dose- and time-dependently by 20.8%-87.1% of the control levels after 24 and 48 h of treatment with 20-160 microM of the inhibitor. Immunoblotting studies showed that both cerulenin and C75 induced poly(ADP-ribose) polymerase (PARP) cleavage in the melanoma cells dose-dependently. Procaspase-3 was also found to be processed into the active and smaller 17 and 19 kDa subunits, and administration of pan-caspase inhibitor Z-VAD-FMK completely rescued the cells from PARP cleavage. This indicated that the cerulenin- and C75-induced apoptosis involved caspase activation. The proapoptotic effects of the FAS inhibitors were further confirmed using confocal microscopy with annexin-V FITC and propidium iodide staining. DNA flow cytometric studies demonstrated that the FAS inhibitors accumulated G2/M cells preceding the elevation of sub G1 or apoptotic cells with fragmented DNA. The induced cell cycle arrest and apoptosis were associated with elevation of p21 and depletion of Bcl-xL and Mcl-1, respectively. Results from this study suggest that FAS inhibitors retard growth of melanoma A-375 cells, involving activation of caspase-dependent apoptosis.
Ho
Tik-Shun
TS
Department of Biology, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR.
Ho
Yuk-Ping
YP
Wong
Wing-Yin
WY
Chi-Ming Chiu
Lawrence
L
Wong
Yum-Shing
YS
Eng-Choon Ooi
Vincent
V
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000494:pharmacology; D000970:Antineoplastic Agents; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D020169:Caspases / Q000502:physiology*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D002569:Cerulenin / Q000494:pharmacology*; D004273:DNA, Neoplasm / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D064429:Fatty Acid Synthases / Q000037:antagonists & inhibitors*; D005434:Flow Cytometry; D019254:Genes, bcl-2 / Q000187:drug effects; D006801:Humans; D008545:Melanoma / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D018613:Microscopy, Confocal; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics; D013778:Tetrazolium Salts; D013844:Thiazoles; D019014:fas Receptor / Q000096:biosynthesis
C406734:4-methylene-2-octyl-5-oxofuran-3-carboxylic acid; D000970:Antineoplastic Agents; D004273:DNA, Neoplasm; D004791:Enzyme Inhibitors; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D009363:Neoplasm Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D013778:Tetrazolium Salts; D013844:Thiazoles; D019014:fas Receptor; D002569:Cerulenin; D064429:Fatty Acid Synthases; D020169:Caspases; C022616:thiazolyl blue; D015107:4-Butyrolactone