RESUMO
AIM:To investigate the regulatory effect of NADPH oxidase-4 (NOX-4) on PI3K signaling path-way in transforming growth factor-β1 (TGF-β1)-induced collagen type Ⅰ (collagen Ⅰ) synthesis from lung cancer cells and the mechanisms. METHODS:Human lung cancer A549 cells were cultured in vitro and stimulated with TGF-β1. The ex-pression of NOX family and collagen family at mRNA and protein levels as well as the PI3K class Ⅰ catalytic subunits and the activation of PI3K signaling pathway was measured. A549 cells were pre-treated with NOX-4 inhibitor diphenyleneiodo-nium (DPI), and the expression of collagen Ⅰ at mRNA level as well as the PI3K class Ⅰ catalytic subunits and the activa-tion of PI3K signaling pathway was measured upon TGF-β1 stimulation. RESULTS:TGF-β1 stimulated the expression of NOX-4 and collagen Ⅰ at mRNA and protein levels as well as the expression of PIK3CD and the activation of PI3K signaling pathway at a dose- and time-dependent manner. NOX-4 inhibitor DPI partly reversed TGF-β1-induced collagen Ⅰ expres-sion. Inhibition of NOX-4 down-regulated the degree of TGF-β1-stimulated activation of PI3K signaling pathway without effect on the expression of PIK3CD. CONCLUSION:NOX-4 participates in TGF-β1-induced collagen Ⅰ synthesis from lung cancer cells via regulating the activation of PI3K signaling pathway. TGF-β1/NOX-4/PI3K signaling pathway axis acts as a regulatory role in collagen Ⅰ synthesis from lung cancer cells.
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Cysteine-rich angiogenic inducer 61(Cyr61/CCN1)is an extracellular matrix-associated signaling protein consisting of 381 amino-acid residues ,which has the regulatory function for a multitude of cellular responses.The pleiotropic effects of CCN 1 on the initiation and resolution of inflammation as well as oncogenesis and development of tumor were reported.According to the numerous data from experimental and clinical studies ,this article provides an overview on CCN1 and summarizes the latest understanding of the role of CCN 1 in pulmonary diseases.