Detection of telomerase activity and correlation with mitotic and apoptotic indices, Ki-67 and expression of cyclins D1 and A in cutaneous melanoma.

Telomerase plays a key role in carcinogenesis. It is activated in most immortal cell lines and human cancers, including cutaneous melanoma (CM). Increased cell proliferation and deregulation of the cell cycle occur in human cancers. Links between telomerase activity (TA), cell proliferation, cell death and expression of cell-cycle regulators have not been extensively elucidated in CM. In this study, we investigated TA, mitotic index (MI), apoptotic index (AI), Ki-67 and nuclear positivity of cyclins D1 and A (Ki-671N/1,000, cyclin D11N/1,000, cyclin A1N/1,000) in 42 primary cutaneous melanomas (PCMs). TA was detected in all cases and directly correlated with MI, Ki-671N/1,000, cyclin D11N/1,000 and cyclin A1N/1,000 (p < 0.001); it was not correlated with AI. When subdividing PCMs into radial and vertical growth phase melanomas (RGPMs, VGPMs), a correlation was maintained only with MI (p < 0.005) and cyclin D11N/1,000 (p < 0.005). Although MI and Ki-671N/1,000 were highly correlated with cyclin D11N/1,000 and cyclin A1N/1,000 (p < 0.001) when considering all cases together, a high correlation was found in the RGPM and VGPM groups between cyclin A1N/1,000 and Ki-671N/1,000 only (p < 0.001), thus suggesting that cyclin A is more closely correlated with cell proliferation than cyclin D1. Our results further support the association between TA, tumor cell proliferation and cyclin D1 and A expression in PCM, though it is possible that links between TA and proliferation, on the one hand, and TA and cyclin D1 expression, on the other, might occur following various pathways.