a b s t r a c tChemo-or radiation-resistance in tumors caused by hypoxia often undermines efficacy of cancer therapy. Thus, therapies that overcome cellular resistance during hypoxia are necessary. SM22a is an actin-binding protein found in smooth muscle, fibroblasts, and some epithelium. We demonstrate that SM22a is induced in A549 non-small cell lung carcinoma cells by hypoxia and its overexpression increased chemo-and radiation-resistance. Hypoxia-mediated induction of SM22a expression is hypoxia-inducible factor-independent. Moreover, SM22a overexpression enhances tumor cell growth and activates the IGF1R/PI3K/Akt pathway via direct interaction with IGF1Rb. Our results suggest SM22a as a novel regulator of hypoxic survival pathway of A549 NSCLC cells.
Structured summary of protein interactions:IGFR1 Beta physically interacts with SM22 alpha by anti bait coimmunoprecipitation (View Interaction: 1, 2)
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