LRP6 targeting suppresses gastric tumorigenesis via P14ARF-Mdm2-P53-dependent cellular senescence.

ABSTRACT

NLRP6, a member of the Nod-like receptor family, protects against chemically induced intestinal injury and colitis-associated colon cancer. However, the cellular mechanisms involved in this NLRP6-mediated protection remain unclear. Here, we show that NLRP6 was down-regulated in approximately 75% of primary gastric cancer cases and exhibited significant associations with advanced clinical-stage lymph node metastasis and poor overall survival. Functional studies established that ectopic overexpression or down-regulation of NLRP6 inhibited cancer cell proliferation by inducing cell cycle arrest at the G1 phase via P21 and Cyclin D1 both in vitro and in vivo. Activation of the P14ARF-P53 pathway played a crucial role in the observed cellular senescence. We further demonstrated that ectopic overexpression of NLRP6 combined with inactivation of NF-κB(p65) and Mdm2 activates P14ARF-P53 to promote the senescence of gastric cancer cells. These findings indicate that NLRP6 functions as a negative regulator of gastric cancer and offer a potential new option for preventing gastric cancer.