LINC00319 acts as a microRNA-335-5p sponge to accelerate tumor growth and metastasis in gastric cancer by upregulating ADCY3.

Gastric cancer (GC) is one of the most common cancers in the world and remains a heavy burden of health worldwide. Adenylate cyclase 3 (ADCY3) is a widely expressed membrane-associated protein in human tissues and has been identified to be a new molecular target of GC. Long noncoding RNAs have a substantial influence on tumorigenesis and progression of tumors by binding to microRNAs. Therefore, this study is to clarify the mechanism by which LINC00319 sponges micro RNA-335-5p (miR-335-5p) to influence the development of GC. Initially, microarray analysis identified GC-related differentially expressed LINC00319 and ADCY3 for this study. The interaction was confirmed that LINC00319 interacted with miR-335-5p to regulate ADCY3. Next, SGC-7901 cells presenting with the lowest LINC00319 expression and the highest miR-335-5p expression were transfected with LINC00319, miR-335-5p inhibitor, or ADCY3 vector to examine their roles in growth and metastasis of GC cells, which was further ascertained by in vivo experiments. LINC00319 was upregulated and miR-335-5p was downregulated in GC cells. LINC00319 overexpression, miR-335-5p inhibitor, or ADCY3 overexpression was shown to significantly elevate the expression of cyclin-dependent kinase 4 and metastasis associated 1, decrease that of growth arrest-specific 1, and promote tumor growth and metastasis by increasing proliferation and migration and reducing cell apoptosis. Importantly, it was found that overexpressed miR-335-5p exerted its tumor suppressive role in GC through downregulating ADCY3. Collectively, LINC00319 expedited growth and metastasis of GC by upregulating miR-335-5p-mediated ADCY3.NEW & NOTEWORTHY This study is carried out based on in vivo and in vitro studies in mice and gastric cancer (GC) cells with the aim of clarifying the role of LINC00319 on GC growth and metastasis, which associated with micro RNA-335-5p-mediated adenylate cyclase 3. Altogether, we identified LINC00319 to be a potential therapy to treat GC.