Effects of microRNA-155 on biological functions of gastric cancer cells and possible mechanism

Abstract

Objective To discuss the deregulation expression level of microRNA (miRNA, miR)-155 in gastric cancer tissue, and its effect on the gastric cancer cell proliferation and cell biology functions such as proliferation and adhesion. Methods We performed a real-time reverse transcriptase-polymerase chain reaction in 42 cases of gastric cancer and the corresponding cancer adjacent tissues, and quantitatively determined the expression level of the miR-155. At the same time, a variety of experimental methods were used to determine whether the abnormal expression of miR-155 could inhibit or promote the viability, proliferation and invasion of the SGC-7901 cells in gastric cancer. Results As compared with normal tissues and cells, the expression of miR-155 in human gastric cancer tissues and SGC-7901 cells was decreased. The proliferation of miR-155 mimics (29.912±1.786) was significantly lower than that of the control group (34.962±1.413), and the differences were statistically significant. The cell viability test revealed that cells in the 50 nmol/L mimics transfection group (91.34±1.33) and the 100 nmol/L transfection group (84.59±1.63) showed significantly lower survival rate than normal gastric cancer cells (94.39±1.07) (P<0.05). Cell adhesion test showed that the absorbance of miR-155 mimics in each experimental group was 0.861±0.051 (30 nmol/L), 0.738±0.055 (50 nmol/L), 0.665±0.042 (80 nmol/L), 0.531±0.032 (100 nmol/L), significantly lower than that in the control group (1.098±0.054) (P<0.01). Conclusion The abnormal low expression of miR-155 may participate in the development process of gastric cancer, and enhance the vitality of gastric cancer cell proliferation and other biological characteristics to achieve the function as a recessive cancer gene. Key words: Gastric cancer; MicroRNA; MicroRNA-155; Proliferation