Background: The receptors for the cardiac hormone atrial natriuretic peptide (ANP), natriuretic peptide receptor A (NPR-A), have been reported to be expressed in lung cancer, prostate cancer, ovarian cancer. NPR-A expression and signaling is important for tumor growth, its deficiency protect C57BL/6 mice from lung, skin, and ovarian cancers, and these result suggest that NPR-A is a new target for cancer therapy. Recently, NPR-A has been demonstrated to be expressed in pre-implantation embryos and in ES cells, it has a novel role in the maintenance of self-renewal and pluripotency of ES cells. However, the direct role of NPR-A signaling in gastric cancer remains unclear.
Method: NPR-A expression was downregulated by transfection of shRNA. The proliferation of gastric cancer cells was measured by Hoechst 33342 stain. Cell proliferation and invasion were determined via BrdU and transwell assays, respectively.
Results: Down-regulation of NPR-A expression by shNPR-A induced apoptosis, inhibited proliferation and invasion in AGS cells. The mechanism of shNPR-A-induced anti-AGS effects was linked to NPR-A-induced expression of KCNQ1, a gene to be overexpressed in AGS and significantly reduced by shNPR-A.
Conclusion: Collectively, these results suggest that NPR-A promotes gastric cancer development in part by regulating KCNQ1. Our findings also suggest that NPR-A is a target for gastric cancer therapy.
Keywords: KCNQ1; NPR-A; gastric cancer.