Glycogen phosphorylase B promotes cell proliferation and migration through PI3K/AKT pathway in non-small cell lung cancer

Abstract

Objective Glycogen phosphorylase B (PYGB), the rate-determining enzyme in glycogen degradation, plays a critical role in progression of various tumors. The present study focused on the potential molecular mechanism toward PYGB in non-small cell lung cancer (NSCLC) progression. Methods Expression of PYGB in NSCLC tissues and cell lines was evaluated via quantitative real-time PCR (qRT-PCR), western blot and immunohistochemistry. Cell viability, proliferation and apoptosis were investigated using 3-(4,5-Dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assay, 5-bromo-2-deoxyuridine (BrdU) and flow cytometry, respectively. Cell migration and invasion ability were detected by wound healing and transwell invasion assays, respectively. The in vivo effect of PYGB on NSCLC tumor growth was determined via subcutaneous xenotransplanted tumor model. Results PYGB was upregulated in NSCLC tissues and cell lines, suggesting a poor prognosis in NSCLC patients. In vitro functional assays indicated that knockdown of PYGB suppressed cell viability, proliferation, migration and invasion, while promoted cell apoptosis in NSCLC. Mechanistically, we found that overexpression of PYGB could activate phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway, while these effects were effectively reversed by knockdown of PYGB. In vivo tumorigenesis and PI3K/AKT signaling pathway were also inhibited by PYGB knockdown. Conclusions Knockdown of PYGB suppressed NSCLC progression, suggesting PYGB as a novel biomarker and potential molecular therapeutic target for further investigation in NSCLC.