Objective: To investigate the expression of COL12A1 in gastric cancer and its biological function.  
Methods: The COL12A1 expression in gastric cancer and its relations with pathological stage and prognosis of gastric cancer were analyzed by using Oncomine and GEPIA online databases. The gene and protein expressions of CLL12A1 in 58 specimens of gastric cancer and tumor adjacent tissue were determined by qPCR and immunohistochemical staining. In gastric cancer SGC7901 cells after CLL12A1 knockdown through siRNA interference technique, the changes in biological behaviors were observed through CCK-8 assay, plate clone formation assay, and Transwell chamber assay, respectively.
Results: Oncomine- and GEPIA-based online analysis indicated that COL12A1 was significantly upregulated in gastric cancer (both P<0.05); COL12A1 expression was irrelevant to the pathological stage of gastric cancer (P>0.05), but the overall survival rate in gastric cancer patients with high COL12A1 expression was significantly decreased (P<0.05). the results of qPCR and immunohistochemical staining showed that both gene and protein expressions of COL12A1 were significantly higher than those in the tumor adjacent tissue (both P<0.05). In gastric cancer SGC7901 cells after CLL12A1 knockdown, the growth, proliferative and invasion abilities were all significantly inhibited (all P<0.05).
Conclusion: COL12A1 is upregulated in gastric cancer, and high COL12A1 expression may probably promote growth, proliferative and invasion abilities of gastric cancer cells, and also related to poor prognosis of the patients.