MIR-373

To investigate the effect of miR-138 targeting PLD2 gene on proliferation and migration of oral cancer cells.

After oral cancer cells were transfected with miR-138, the expression level of microRNA-138 was detected by RT-PCR assay, the proliferation ability was detected by MTT assay, and cell cycle distribution was detected by flow cytometry. Transwell migration assay was used to detect cell migration ability, Western blotting assay was used to detect the expression levels of MMP-9, PLD2 and cyclin D1 in gastric cancer cells. Luciferase assay was used to report the targeting relationship between microRNA-138 and PLD2 gene. SPSS 21.0 software package was used to analyze the data.

After miR-138 was transfected into oral cancer cells, the relative expression level of miR-138 was 4.28±0.16, which was significantly higher than that of blank control and miR-NC group (P<0.05). Luciferase reporter gene assay showed that the relative activity of PLD2 wild plasmid luciferase was significantly lower in oral cancer cells transfected with microRNA-138 than in other groups (P<0.05); The expression level of PLD2 gene in miR-138 group was significantly lower than that in blank control group and miR-NC group (P<0.05). After oral cancer cells were transfected with miR-138, the proliferation ability of oral cancer cells in miR-373 group was significantly lower than that in control group and miR-NC group (P<0.05). Flow cytometry showed that the ratio of G0/G1 phase was (64.39±6.49)% in the group of miR-138, which was significantly higher than that in the blank control group and the group of miR-NC(P<0.05); The ratio of S phase in the group of miR-138 was(13.28±3.16)%, which was significantly lower than that in the blank control group and the group of miR-NC (P<0.05); There was no significant difference in the ratio of G2/M phase among the groups (P>0.05). Transwell experiment showed that the number of migrating cells transfected with miR-138 in oral cancer cells was 138.46±24.37, which was significantly lower than that in blank control group and miR-NC group(P<0.05). Western blotting experiments showed that the relative levels of MMP-9, vimentin and cyclin D1 in the miR-138 group were 0.14±0.04, 0.17±0.02 and 0.15±0.03, respectively, which were significantly lower than those in the blank control group and the miR-NC group(P<0.05).

miR-138 can target PLD2 gene expression and inhibit the proliferation and migration of oral cancer cells.

The abnormal expression of microRNAs (miRNAs) is critical for the development of human cancers. However, the functions of many miRNAs remain to be elucidated. miR-373 was reported to involve the tumorigenesis of multiple cancers, but its role in nasopharyngeal carcinoma (NPC) is not clear. Quantitative real-time PCR was performed to analyze miR-373 expression in NPC cell lines. The connection between membrane associated ring-CH-type finger 5 (MARCH5) and miR-373 was analyzed using a luciferase activity reporter assay and western blot. A cell counting kit-8 assay, a colony formation assay, and a wound-healing assay were performed to investigate the biological functions of miR-373 and MARCH5. We showed miR-373 expression is downregulated, and MARCH5 expression is upregulated, in NPC cells. MARCH5 was validated as a direct target of miR-373. miR-373 regulates NPC cell proliferation, colony formation, and cell migration by regulating MARCH5. In conclusion, our study showed that miR-373 has a tumor suppressive role in NPC by targeting MARCH5. This may provide novel therapeutic targets for NPC.