Inhibition of heat shock protein 27 phosphorylation promotes sensitivity to 5-fluorouracil in colorectal cancer cells

Atsushi Matsunaga, Yoshiyuki Ishii, Masashi Tsuruta, Koji Okabayashi, Hirotoshi Hasegawa, Yuko Kitagawa

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

The aim of the present study was to investigate whether the inhibition of HSP27 phosphorylation, which affects certain cellular functions, modulates sensitivity to 5-fluorouracil (5-FU) in colorectal cancer cells. Exposure to 5-FU in HCT116 and HCT15 cells expressing high levels of HSP27 with a low 5-FU sensitivity caused a minimal change in HSP27 expression, but induced the upregulation of HSP27 phosphorylation, particularly at Ser78. By contrast, exposure to 5-FU in HT29 cells expressing a low level of HSP27 with a high 5-FU sensitivity marginally increased HSP27 expression, with minimal phosphorylation. Treatment with a selective inhibitor, p38 mitogen-activated protein kinase (MAPK; SB203580), caused the dose-dependent suppression of HSP27 phosphorylation, which was upregulated by 5-FU, reducing the half maximal inhibitory concentration values of 5-FU in the HCT116 and HCT15 cells. However, treatment with SB203580 exhibited no significant effect on cell growth or survival. In conclusion, this study indicated that the inhibition of HSP27 phosphorylation by a selective inhibitor of p38 MAPK promotes 5-FU sensitivity without causing cytotoxicity in colorectal cancer cells.

Original languageEnglish
Pages (from-to)2496-2500
Number of pages5
JournalOncology Letters
Volume8
Issue number6
DOIs
Publication statusPublished - 2014 Dec 1

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Keywords

  • 5-fluorouracil
  • Colorectal cancer
  • Heat shock protein 27 (HSP27)
  • Phosphorylation
  • Sensitivity

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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