Inhibition of nuclear factor kappaB induces apoptosis following treatment with tumor necrosis factor alpha and an antioxidant in human prostate cancer cells.
Transforming growth factor beta-1 (TGFbeta-1) and tumor necrosis factor alpha (TNF-alpha), an activator of nuclear factor kappa B (NF-kappaB), modulate apoptosis and/or cell growth. This study was designed to investigate the activity of NF-kappaB and its regulation of inhibitor of apoptosis gene (c-IAP2) in two human prostate cancer cell lines, DU-145 (which is androgen unresponsive) and ALVA-101 (which is moderately androgen responsive). These cells were treated with and without various concentrations of a strong antioxidant, pyrrolidinedithiocarbamate (PDTC), and TNF-alpha at various time intervals. Following treatments, cell growth and apoptosis were determined by ELISA techniques. NF-kappaB activity was determined by electrophoretic mobility shift assay (EMSA), and c-IAP2 mRNA production was determined with Northern blot analysis. PDTC treatment significantly reduced cell growth up to 80% in both DU-145 and ALVA-101 cells. TNF-alpha and lower but not higher doses of PDTC combined demonstrated an additive inhibition of cell growth in both cell lines. Active NF-kappaB and c-IAP2 was blocked significantly following PDTC treatments, whereas treatments with TNF-alpha alone showed increased NF-kappaB activity and c-IAP2. However, when both PDTC and TNF-alpha were combined, nuclear presence of NF-kappaB and c-IAP2 were reduced significantly (P < 0.05) to levels observed with PDTC alone. In conclusion, the antioxidant, PDTC, appears to initiate apoptosis by blocking cytoplasmic NF-kappaB translocation to the nucleus where it normally activates the production of apoptosis-inhibitory proteins like c-IAP2. Both TNF-alpha and PDTC alone cause apoptosis and reduce cell growth, but their combined effects are additive in reducing cell growth of DU-145 and ALVA-101 human prostate cancer cells.
Gunawardena
Kushlani
K
Department of Medicine and Pathology, University of Utah School of Medicine, Salt Lake City 84132, USA.
Murray
Darrell K
DK
Swope
Richard E
RE
Meikle
A Wayne
AW
D000970:Antineoplastic Agents / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects*; D003196:Computer Graphics; D006801:Humans; D008297:Male; D016328:NF-kappa B / Q000096:biosynthesis* / Q000187:drug effects; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000187:drug effects; D011392:Proline / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D014176:Protein Biosynthesis; D011506:Proteins / Q000187:drug effects; D013859:Thiocarbamates / Q000627:therapeutic use*; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000627:therapeutic use*
D000970:Antineoplastic Agents; D016328:NF-kappa B; D009363:Neoplasm Proteins; D011506:Proteins; D013859:Thiocarbamates; D014409:Tumor Necrosis Factor-alpha; C066229:prolinedithiocarbamate; D011392:Proline