Abstract
Adenylate cyclase 3 (ADCY3) is a widely expressed membrane-associated protein in human tissues, which catalyzes the formation of cyclic adenosine-3',5'-monophosphate (cAMP). However, our transcriptome analysis of gastric cancer tissue samples (NCBI GEO GSE30727) revealed that ADCY3 expression was specifically altered in cancer samples. Here we investigated the tumor-promoting effects of ADCY3 overexpression and confirmed a significant correlation between the upregulation of ADCY3 and Lauren's intestinal-type gastric cancers. ADCY3 overexpression increased cell migration, invasion, proliferation, and clonogenicity in HEK293 cells; conversely, silencing ADCY3 expression in SNU-216 cells reduced these phenotypes. Interestingly, ADCY3 overexpression increased both the mRNA level and activity of matrix metalloproteinase 2 (MMP2) and MMP9 by increasing the levels of cAMP and phosphorylated cAMP-responsive element-binding protein (CREB). Consistent with these findings, treatment with a protein kinase A (PKA) inhibitor decreased MMP2 and MMP9 expression levels in ADCY3-overexpressing cells. Knockdown of ADCY3 expression by stable shRNA in human gastric cancer cells suppressed tumor growth in a tumor xenograft model. Thus, ADCY3 overexpression may exert its tumor-promoting effects via the cAMP/PKA/CREB pathway. Additionally, bisulfite sequencing of the ADCY3 promoter region revealed that gene expression was reduced by hypermethylation of CpG sites, and increased by 5-Aza-2'-deoxycytidine (5-Aza-dC)-induced demethylation. Our study is the first to report an association of ADCY3 with gastric cancer as well as its tumorigenic potentials. In addition, we demonstrate that the expression of ADCY3 is regulated through an epigenetic mechanism. Further study on the mechanism of ADCY3 in tumorigenesis will provide the basis as a new molecular target of gastric cancer.
Highlights
Gastric cancer is the fourth most prevalent cancer type and the second largest contributor to cancer-related deaths worldwide
We provide the first evidence that upregulation of Adenylate cyclase 3 (ADCY3) in gastric cancer cells and tissues is associated with increased tumorigenic potential
We further investigated the effects of cAMP accumulation on the progression of gastric cancer by measuring cAMP-responsive element-binding protein (CREB) activity by comparing the amounts of total CREB (t-CREB) and phosphorylated CREB (p-CREB) at the Ser133 residue
Summary
Gastric cancer is the fourth most prevalent cancer type and the second largest contributor to cancer-related deaths worldwide. In Korea and Japan, high incidence rates of gastric cancer have prompted the initiation of national cancer screening programs [2] These programs have led to the diagnosis and treatment of 50% more patients with early gastric cancer than was previously possible [3,4], thereby contributing to decreased mortality [5]. Gene regulation patterns and tissue distribution appear to be family member-specific, indicating these distinct functions are important in achieving precise regulation of cellular signals in a spatiotemporal manner. Consistent with this idea, knockout and transgenic mice models have revealed distinctive physiological roles for each adenylate cyclase family member [11]. DNA methylation analysis of the promoter region indicates that ADCY3 expression is regulated through an epigenetic mechanism
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
