Abnormal regulation of apoptosis is an important aspect of tumour development. Capsaicin, an extract of red chilli peppers, has been shown to inhibit growth of melanoma and other malignant cell lines and HA14-1 is an organic compound that directly induces apoptosis by binding to Bcl-2 protein. The aim of this work was to investigate whether combination therapy with capsaicin and HA14-1 might hold any promise for the treatment of melanoma. Three melanoma cell lines of a range of aggressive potential, melanocytes and fibroblasts were examined, looking at the effects of both drugs singly and in combination on cell viability and induction of apoptosis. This comparative study showed that melanoma cells and melanocytes have a similar sensitivity to capsaicin while fibroblasts are more resistant to it. HA14-1, as expected, induced apoptosis in all cells at relatively low concentrations. A combination of the two agents produced the expected results of an additive effect for 2 (HBL and A375SM) out of 3 melanoma cell lines in inducing apoptosis, but encouragingly for the most metastatically aggressive cancer cell line (C8161), a combination of the two showed a synergistic induction of apoptosis.
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