GRIK5 stimulates colon cancer growth and metastasis through cAMP/PKA/CADM3 signaling

Abstract

Glutamate receptor, ionotropic, kainate 5 (GRIK5) is a member of glutamate receptors participating, and the kainate receptor family has been proved to regulate cell proliferation and transformation. Our study aimed at exploring the role of GRIK5 in colon tumor progression. Three hundred and ninety eight colon cancer patients in The Cancer Genome Atlas Program (TCGA) data set and 26 clinical colon cancer patients were included for GRIK5 expression and prognosis analysis. GRIK5 overexpressed HCT116 and CT26 cell lines were established for cell proliferation and Transwell assay. Western blot analysis and immunostaining assay was conducted to evaluate the activation of activation of cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/cell adhesion molecular 3 (CADM3) signaling in cell lines and tumor tissues. Subcutaneous CT26-bearing mice model was established to examine GRIK5-induced tumor growth and metastasis in vivo. Our study identified GRIK5 to be upregulated in patients with colon cancer, and higher GRIK5 levels correlated with the poor overall survival in patients. In vitro, GRIK5 overexpression markedly enhanced the proliferative properties and aggressive behaviors of colon cancer cells. Mechanistically, GRIK5 induced the activation of cAMP/PKA signaling, proceeded with augmented CADM3 expression, eventually resulting in sustained tumor growth. GRIK5 was a crucial scaffold in enabling colon cancer growth and metastasis, which offered a promising target for therapeutic manipulation of colon cancer.

Keywords: CADM3; GRIK5; cAMP; colon cancer; metastasis.