Background
This study aims to investigate the effect of miR-212-5p overexpression targeting suppressor of cytokine signaling 5 (SOCS5) on the malignant proliferation of liver cancer cells HepG2 and tumor formation in nude mice with transplanted tumors.
Conclusions
miR-212-5p overexpression down-regulated SOCS5 could inhibit the malignant proliferation of HCC cells HepG2 and tumor formation in nude mice with transplanted tumors.
Methods
Luciferase reporter assay was used to detect the targeted relationship between miR-212-5p and SOCS5, and SOCS5 was overexpressed by the SOCS5 pcDNA vector. MiR-212-5p mimic and pc DNA-SOCS5 were transfected into liver cancer HepG2 cells alone or in combination, and the cells were randomly divided into four groups, the control group, mimic group, SOCS5 group and mimic + SOCS5 group for subsequent experiments. The orthotopic xenograft mouse models were established by using HepG2 cells in BALB/c athymic nude mice.
Results
The results showed that there was a direct targeting relationship between miR-212-5p and SOCS5. Compared with the control group, the clone formation rate, the levels of Ki67, and proliferating cell nuclear antigen (PCNA) protein in the mimic group were significantly lower (P<0.05), but the apoptosis rate was significantly higher (P<0.05). The ratio of Bax/Bcl-2, cleaved Caspase-3/Caspase-3, and cleaved Caspase-9/Caspase-9 was significantly higher (P<0.05), while the ratios of p-phosphatidylinositol 3 kinase (PI3K)/PI3K, p- Protein kinase B (AKT)/AKT, and p-mammalian target of rapamycin (mTOR)/mTOR were significantly reduced (P<0.05). In the SOCS5 group, the result was reversed. Interesting, In the mimic+SOCS5 group the clone formation rate, the protein levels of Ki67, and PCNA were significantly decreased (P<0.05) while the apoptosis rate was significantly increased (P<0.05). The ratio of Bax/Bcl-2, cleaved Caspase-3/Caspase-3, and cleaved Caspase-9/Caspase-9 was significantly increased (P<0.05). The ratios of p-PI3K/PI3K, p-Akt/AKT, and p-mTOR/mTOR were significantly reduced (P<0.05). In vivo, The level of miR-212-5p was significantly increased, with SOCS5 decreased (P<0.05). Furthermore, the number of Ki67 positive cells was significantly reduced (P<0.05), and the apoptosis rate increased significantly (P<0.05). Additionally, the ratio of p-PI3K/PI3K, P-AKT/AKT, P-mTOR/mTOR decreased significantly (P<0.05). Conclusions: miR-212-5p overexpression down-regulated SOCS5 could inhibit the malignant proliferation of HCC cells HepG2 and tumor formation in nude mice with transplanted tumors.