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Calcium and calcium sensing receptor modulates the expression of thymidylate synthase, NAD(P)H:quinone oxidoreductase 1 and survivin in human colon carcinoma cells: Promotion of cytotoxic response to mitomycin C and fluorouracil
Author(s) -
Liu Guangming,
Hu Xin,
Varani James,
Chakrabarty Subhas
Publication year - 2009
Publication title -
molecular carcinogenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.254
H-Index - 97
eISSN - 1098-2744
pISSN - 0899-1987
DOI - 10.1002/mc.20470
Subject(s) - biology , cytotoxic t cell , survivin , cancer research , calcium sensing receptor , receptor , mitomycin c , apoptosis , microbiology and biotechnology , calcium , biochemistry , medicine , calcium metabolism , in vitro , genetics
Ca 2+ and the cell‐surface calcium sensing receptor (CaSR) constitute a novel and robust ligand/receptor system in regulating the proliferation and differentiation of colonic epithelial cells. Here we show that activation of CaSR by extracellular Ca 2+ (or CaSR agonists) enhanced the sensitivity of human colon carcinoma cells to mitomycin C (MMC) and fluorouracil (5‐FU). Activation of CaSR up‐regulated the expression of MMC activating enzyme, NAD(P)H:quinone oxidoreductase 1 (NQO‐1) and down‐regulated the expression of 5‐FU target, thymidylate synthase (TS) and the anti‐apoptotic protein survivin. Cells that were resistant to drugs expressed little or no CaSR but abundant amount of survivin. Disruption of CaSR expression by shRNA targeting the CaSR abrogated these modulating effects of CaSR activation on the expression of NQO1, TS, survivin and cytotoxic response to drugs. It is concluded that activation of CaSR can enhance colon cancer cell sensitivity to MMC and 5‐FU and can modulate the expression of molecules involved in the cellular responses to these cytotoxic drugs. © 2008 Wiley‐Liss, Inc.