Angiogenesis inhibition has been shown to enhance the therapeutic efficacy of cytotoxic chemotherapy in colorectal cancer. The basis of the contribution of this modality has not been defined fully. To determine the potential role of hypoxia-induced apoptosis, we studied a series of colon cancer cell lines with varying susceptibility to hypoxia.
View Article and Find Full Text PDFThe dithiolethione oltipraz is a potent chemopreventive agent in preclinical models, and induces the expression of protective enzymes in the colon mucosa and peripheral mononuclear cells of treated human subjects. We investigated the effects of oltipraz on DT-diaphorase expression in HT29 colon adenocarcinoma cells. Following a 24-hr exposure to 100 microM oltipraz, elevated steady-state levels of mRNA for Jun and Fos family members were observed.
View Article and Find Full Text PDFHuman ovarian cancer cell lines derived from A2780 by stepwise exposure to increasing cisplatin concentrations show progressive resistance to cisplatin. Previous studies have shown increased cellular glutathione and elevated steady-state expression of gamma-glutamylcysteine synthetase (gamma-GCS) and of the transcription factor c-Jun, all in proportion to the level of resistance in the resistant cells. We hypothesized that c-Jun was an important locus of control of the detoxicating enzymes mediating resistance, and that resistance reversal would be achieved by specific inhibition of this mechanism.
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