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The 15‐lipoxygenase‐1 expression may enhance the sensitivity to non‐steroidal anti‐inflammatory drug‐induced apoptosis in colorectal cancers from patients who are treated with the compounds
Author(s) -
Yoshinaga Masahiro,
Murao Hiroyuki,
Kitamura Yosuke,
Koga Koutaro,
Tsuruta Satoru,
Igarashi Hisato,
Nakamura Kazuhiko,
Takayanagi Ryoichi
Publication year - 2007
Publication title -
journal of gastroenterology and hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.214
H-Index - 130
eISSN - 1440-1746
pISSN - 0815-9319
DOI - 10.1111/j.1440-1746.2007.04842.x
Subject(s) - apoptosis , medicine , tunel assay , colorectal cancer , transfection , cyclooxygenase , lipoxygenase , immunohistochemistry , pharmacology , cancer research , cancer , enzyme , cell culture , biochemistry , chemistry , biology , genetics
Background and Aim: Non‐steroidal anti‐inflammatory drugs (NSAIDs) can prevent colorectal cancer (CRC), but their effect is limited. Recent studies have shown the involvement of 15‐lipoxygenase‐1 (15‐LOX‐1) in NSAID‐induced apoptosis in colorectal carcinoma cells. We evaluate whether 15‐LOX‐1 expression influences the sensitivity of NSAID‐induced apoptosis in CRCs. Methods: In 22 CRC surgical samples from NSAID users who had been constant for more than 5 years and 28 CRC surgical samples from NSAID non‐users, the expressions of 15‐LOX‐1, cyclooxygenase‐2 (COX‐2), beta‐catenin, and p53 were analyzed using immunohistochemistry. TUNEL assay was also performed for samples. The effects of the transient transfection of 15‐LOX‐1 cDNA on indomethacin‐induced apoptosis were certified in HCT‐116 cells. The effects of adding 13‐S‐hydroxyoctadecadinoic acid (13‐S‐HODE) on indomethacin‐induced apoptosis were also examined in HCT‐116 cells. The levels of apoptosis were determined by the analysis of the floating‐cells ratio and DNA gel electrophoresis. Results: The expression of 15‐LOX‐1 on CRCs from NSAID users was significantly decreased compared with those from NSAID non‐users; however, the expressions of other molecules were not significantly different between two groups. The levels of TUNEL scoring in samples from NSAID users were similar to those from NSAID non‐users. Indomethacin (100 μM) induced less apoptosis in mocked cells, whereas the same concentrations of indomethacin enhanced the level of apoptosis in 15‐LOX‐1‐transfected cells. 13‐S‐HODE also increased the level of indomethacin‐induced apoptosis in cells. Conclusion: Results suggest that 15‐LOX‐1 expression may be one of the mechanisms which enhance the sensitivity to NSAID‐induced apoptosis in CRCs from patients who are treated with the compounds.