Immunoglobulin kappa and immunoglobulin lambda are required for expression of the anti-apoptotic molecule Bcl-xL in human colorectal cancer tissue Academic Article uri icon

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abstract

  • OBJECTIVE: Aberrant expression of immunoglobulin (Ig) by cancer cells has been documented in a number of malignant tumors but its biological significance is unclear. Cancer cells overexpress anti-apoptotic molecules such as Bcl-xL. The present study aimed to examine the role of expression of Ig light-chain Igk and Iglambda in maintaining the high levels of Bcl-xL in colorectal cancer cells. MATERIAL AND METHODS: Thirty patients with colorectal cancer were recruited to this study. Expression of Igk, Iglambda and Bcl-xL in surgically removed cancer tissue was examined by immunohistochemistry and/or flow cytometry. Using the HT29 cell line as a study platform, RNA interference (RNAi) was employed to knock out the genes of Igk and Iglambda in the cancer cell line; the expression of Bcl-xL in HT29 cells was subsequently analyzed. RESULTS: Human colorectal cancer cells, but not normal colorectal tissue, expressed both Igk and Iglambda in the cytoplasm. High levels of Bcl-xL were detected in cancer cells. Using RNAi to knock out the genes of Igk and/or Iglambda, Bcl-xL expression in HT29 cells was significantly suppressed and the cells became apoptotic. CONCLUSION: The results suggest that expression of Igk and Iglambda is required to stabilize Bcl-xL expression in cancer cells.

authors

  • Yang, Shao-Bo
  • Chen, Xiao
  • Wu, Ben-Yan
  • Wang, Meng-Wei
  • Cai, Chang-Hao
  • Cho, Dan-Bi
  • Chong, Jasmine
  • Li, Ping
  • Tang, Shangguo
  • Yang, Ping-Chang

publication date

  • December 2009