Mechanisms of Apoptosis Induced by Anticancer Compounds in Melanoma Cells

Andrei      L. Gartel

Abstract

The sensitivity of cancer cells to apoptosis induced by anticancer drugs in vitro may be a predictor of their sensitivity to these drugs in vivo. In this review I summarize recent data describing anticancer drug-induced apoptosis in human melanoma cells. Proteasome inhibitors alone, or in combination with other drugs, efficiently induce apoptosis in melanoma cells. It has been shown that apoptosis induced by proteasome inhibitors is linked to suppression of transcription factor FoxM1 and upregulation of the proapoptotic Noxa protein. In addition, proteasome inhibitors stabilize the antiapoptotic Mcl-1 protein, and its suppression leads to more robust apoptosis in melanoma cells. Drugs targeting B-Raf (BAY 54-9085) or IKKb (BMS-345541) have been tested in melanoma cell lines, and it has been shown that the proapoptotic activity of both drugs depends on the inhibition of NF-kB in melanoma cells. A synthetic analog of dsRNA in complex with a polycation stimulated autophagy via induction of dsRNA helicase MDA-5 followed by apoptosis that was partially modulated by Noxa. These data may provide important information needed for designing more efficient combinations of anticancer drugs against melanoma.

Keywords: Apoptosis, FOXM1, Noxa, NF-kB, proteasome inhibitors, Mcl-1, ARC, thiostrepton, Malignant melanoma, multiple caspases, mitochondria, endoplasmic reticulum (ER), proapoptotic protein