Stress-induced down-regulation of tumor-associated NADH oxidase during apoptosis in transformed cells.
Tumor-associated NADH oxidase (tNOX) is a growth-related protein expressed in transformed cells. tNOX knockdown using RNA interference leads to a significant reduction in HeLa cell proliferation and migration, indicating an important role for tNOX in growth regulation and the cancer phenotype. Here, we show that tNOX is down-regulated during apoptosis in HCT116 cells. Treatment with diverse stresses induced a dose- and time-dependent decrease in tNOX expression that was concurrent with apoptosis. Moreover, shRNA-mediated tNOX knockdown rendered cells susceptible to apoptosis, whereas re-expression of tNOX partially recovered cell proliferation. Our results indicate that tNOX is suppressed during apoptosis and demonstrate that tNOX down-regulation sensitizes cells to stress-induced growth reduction, suggesting that tNOX is required for transformed cell growth.
Mao
Liang-Chi
LC
Institute of Biomedical Sciences, National Chung Hsing University, Taichung 40227, Taiwan, ROC.
Wang
Hsi-Ming
HM
Lin
You-Yu
YY
Chang
Te-Kau
TK
Hsin
Yi-Hong
YH
Chueh
Pin Ju
PJ
D017209:Apoptosis / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D015536:Down-Regulation; D055785:Gene Knockdown Techniques; D006801:Humans; D009247:NADH, NADPH Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism; D013312:Stress, Physiological; D014466:Ultraviolet Rays
D009247:NADH, NADPH Oxidoreductases; C431909:tumor-associated NADH oxidase; D010447:Peptide Hydrolases