Guangyong Geng1, Xin Liu2, Aman Xu1, Zhen Lu1, Kaiwei Chen1, Juntong He1, Dongjiang Qi1, Xiao Yuan1. 1. Department of General Surgery, the Fourth Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China. 2. PET-CT Center, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China.
Abstract
BACKGROUND: The tumor suppressor role of tissue factor pathway inhibitor 2 (TFPI-2) has been reported in various tumors. The present study aimed to improve the understanding of the oncogenic properties of TFPI-2 in gastric cancer. METHODS: Relative expression of TFPI-2 was determined by a real-time polymerase chain reaction (PCR) and western blotting, respectively. Cell viability was measured via a cell counting kit-8 assay and proliferation was evaluated by a colony formation assay. Cell apoptosis was assessed with a caspase-3 activity kit and invasion was evaluated by a transwell chamber assay. The methylation level of TFPI-2 promoter was assayed by methylation-specific PCR. The regulatory effect of miR-27a-3p on TFPI-2 was analyzed with a luciferase reporter assay. The direct association between miR-27a-3p and TFPI-2 was shown by biotin-labelling pulldown. RESULTS: TFPI-2 was down-regulated in gastric cancer, which associated with an unfavorable prognosis clinically. Ectopic introduction of TFPI-2 greatly compromised cell viability, colony formation and invasive capacity, and also induced cell apoptosis simultaneously. The promoter region of TFPI-2 was extensively methylated in gastric cancer tissues compared to normal tissues, suggesting the epigenetic inhibition of TFPI-2 expression. We further identified that TFPI-2 functioned as sponge RNA against miR-27a-3p. Most importantly, miR-27a-3p-specific inhibitor significantly exerted a tumor suppressor function akin to TFPI-2 itself, and the anti-tumoral activities were completely abolished by TFPI-2 knockdown. CONCLUSIONS: We found that the epigenetically suppressed TFPI-2 compromised sponging effects with respect to miR-27a-3p in gastric cancer, which consequently and mechanistically contributed to the tumor biology of gastric cancer.
BACKGROUND: The tumor suppressor role of tissue factor pathway inhibitor 2 (TFPI-2) has been reported in various tumors. The present study aimed to improve the understanding of the oncogenic properties of TFPI-2 in gastric cancer. METHODS: Relative expression of TFPI-2 was determined by a real-time polymerase chain reaction (PCR) and western blotting, respectively. Cell viability was measured via a cell counting kit-8 assay and proliferation was evaluated by a colony formation assay. Cell apoptosis was assessed with a caspase-3 activity kit and invasion was evaluated by a transwell chamber assay. The methylation level of TFPI-2 promoter was assayed by methylation-specific PCR. The regulatory effect of miR-27a-3p on TFPI-2 was analyzed with a luciferase reporter assay. The direct association between miR-27a-3p and TFPI-2 was shown by biotin-labelling pulldown. RESULTS:TFPI-2 was down-regulated in gastric cancer, which associated with an unfavorable prognosis clinically. Ectopic introduction of TFPI-2 greatly compromised cell viability, colony formation and invasive capacity, and also induced cell apoptosis simultaneously. The promoter region of TFPI-2 was extensively methylated in gastric cancer tissues compared to normal tissues, suggesting the epigenetic inhibition of TFPI-2 expression. We further identified that TFPI-2 functioned as sponge RNA against miR-27a-3p. Most importantly, miR-27a-3p-specific inhibitor significantly exerted a tumor suppressor function akin to TFPI-2 itself, and the anti-tumoral activities were completely abolished by TFPI-2 knockdown. CONCLUSIONS: We found that the epigenetically suppressed TFPI-2 compromised sponging effects with respect to miR-27a-3p in gastric cancer, which consequently and mechanistically contributed to the tumor biology of gastric cancer.