Effects of the Hippo Signaling Pathway in Human Gastric Cancer


Background/Aim: The Hippo signaling pathway is a newly discovered and conserved signaling cascade,which regulates organ size control by governing cell proliferation and apoptosis. This study aimed to investigateits effects in human gastric cancer.
Methods: Tumor tissues (n=60), adjacent non-tumor tissues (n=60) andnormal tissues (n=60) were obtained from the same patients with primary gastric cancer (GC). In addition,70 samples of chronic atrophic gastritis (CAG) tissues were obtained from patients with intestinal metaplasia(IM) by endoscopic biopsy. Hippo signaling molecules, including Mst1, Lats1, YAP1, TAZ, TEAD1, Oct4 andCDX2, were determined by quantitative polymerase chain reaction (qPCR). Protein expression of Mst1, Lats1,YAP1, TEAD1 and CDX2 was assessed by immunohistochemistry and Western blotting.
Results: Mst1, Lats1and Oct4 mRNA expression showed an increasing tendency from GC tissues to normal gastric tissues, while themRNA expression of YAP1, TAZ and TEAD1 was up-regulated (all P<0.01). Mst1 and Lats1 protein expressionpresented a similar trend with their mRNA expression. In addition, YAP1 and TEAD1 protein expression in GCwas significantly higher than in the other groups (all P<0.01). CDX2 mRNA and protein expression in the CAGgroup were higher than in the other groups (all P<0.01). In GC, mRNA expression of Mst1, Lats1, Oct4, YAP1,TAZ, TEAD1 and CDX2 had a close correlation with lymphatic metastasis and tumor TNM stage (all P<0.01).Furthermore, protein expression of Mst1, Lats1 ,YAP1, TAZ, TEAD1 and CDX2 had a close correlation betweeneach other (P<0.05).
Conclusion: The Hippo signaling pathway is involved in the development, progression andmetastasis of human gastric cancer. Therefore, manipulation of Hippo signaling molecules may be a potentialtherapeutic strategy for gastric cancer.