Anti-Gastric Cancer Effect of Purified Omphalia Lapidescens Protein via Regulating the JAK/STAT3 Signaling Pathway

Abstract Background : Gastric cancer is the leading cause of cancer-related death worldwide. The aim of present study was to investigate the anti-tumor effect of purified Omphalia lapidescens protein (pPeOp) in gastric cancer. Methods : Microarray analysis was performed to find out differentially expressed genes in pPeOp-treated MC-4 gastric cancer cells. The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) 3 signaling pathway was most likely to be altered after bioinformatics analysis. Interleukin-6 (IL-6) and NSC74859 were used as the agonist and inhibitor of the JAK/STAT3 signaling pathway, respectively. Flow cytometry and MTS assay were used for cell proliferation and viability analysis in pPeOp-treated gastric cell lines with IL-6 or NSC74859. Results : The anti-tumor effect was increased when pPeOp were co-treated with IL-6, while decreased in inhibitor treatment. The expression of the crucial members in the pathway of MC-4 cells, including glycoprotein 130 (GP130), JAK1, JAK2, STAT3, p-STAT3, suppressor of cytokine signaling SOCS1 and SOCS3, was investigated by western blotting. Conclusion : pPe O p exhibited promising anticancer effect in the xenograft nude mice model, established by STAT3 knock down gastric cancer cells. Thus, JAK/STAT3 inhibition partially contributed to the anticancer effect of pPeOp, which may serve as a novel strategy for gastric cancer.