Selective induction of cell death in melanoma cell lines through targeting of Mcl-1 and A1

PLoS One. 2012;7(1):e30821. doi: 10.1371/journal.pone.0030821. Epub 2012 Jan 24.

Abstract

Melanoma is an often fatal form of skin cancer which is remarkably resistant against radio- and chemotherapy. Even new strategies that target RAS/RAF signaling and display unprecedented efficacy are characterized by resistance mechanisms. The targeting of survival pathways would be an attractive alternative strategy, if tumor-specific cell death can be achieved. Bcl-2 proteins play a central role in regulating survival of tumor cells. In this study, we systematically investigated the relevance of antiapoptotic Bcl-2 proteins, i.e., Bcl-2, Bcl-xL, Bcl-w, Mcl-1, and A1, in melanoma cell lines and non-malignant cells using RNAi. We found that melanoma cells required the presence of specific antiapoptotic Bcl-2 proteins: Inhibition of Mcl-1 and A1 strongly induced cell death in some melanoma cell lines, whereas non-malignant cells, i.e., primary human fibroblasts or keratinocytes were not affected. This specific sensitivity of melanoma cells was further enhanced by the combined inhibition of Mcl-1 and A1 and resulted in 60% to 80% cell death in all melanoma cell lines tested. This treatment was successfully combined with chemotherapy, which killed a substantial proportion of cells that survived Mcl-1 and A1 inhibition. Together, these results identify antiapoptotic proteins on which specifically melanoma cells rely on and, thus, provide a basis for the development of new Bcl-2 protein-targeting therapies.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Death / drug effects
  • Cell Death / genetics
  • Cell Line, Tumor
  • Cells, Cultured
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Melanoma / drug therapy*
  • Melanoma / genetics
  • Melanoma / pathology*
  • Minor Histocompatibility Antigens
  • Molecular Targeted Therapy / methods*
  • Myeloid Cell Leukemia Sequence 1 Protein
  • Primary Cell Culture
  • Proto-Oncogene Proteins c-bcl-2 / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • RNA Interference / physiology
  • RNA, Small Interfering / pharmacology
  • RNA, Small Interfering / therapeutic use
  • Skin / cytology
  • Skin / drug effects
  • Skin Neoplasms / drug therapy*
  • Skin Neoplasms / genetics
  • Skin Neoplasms / pathology*
  • Substrate Specificity / genetics
  • Up-Regulation / drug effects
  • Up-Regulation / genetics

Substances

  • BCL2-related protein A1
  • Minor Histocompatibility Antigens
  • Myeloid Cell Leukemia Sequence 1 Protein
  • Proto-Oncogene Proteins c-bcl-2
  • RNA, Small Interfering