miR-216a expression in osteosarcoma tissues and its effect on the proliferation, migration, and autophagy of the osteosarcoma U2OS cell line

Objective: To study the expression of miR-216a in osteosarcoma tissues and how it works on the proliferation, migration, and autophagy of the osteosarcoma U20S cell line. Methods: Patients diagnosed with osteosarcoma who underwent surgery in our hospital from March 2018 to March 2020 were recruited as the study cohort, and their tumor tissues and corresponding paracancerous tissues were collected to determine their miR-216a expression levels. A miR-216a inhibitor and a miR-216a negative control were transfected into U2OS cells using liposomes, and the cells were divided into a no-treatment control group (non-transfected), a negative control group (transfection of miR-NC), and a miR-216a inhibitor group (transfected with a miR-216a inhibitor). The following tests were conducted for each group of cells: cell proliferation (using the MTT method), miR-216a expression (using the qRT-PCR method), cell invasion ability (using a Transwell assay), cell migration ability (using a scratch test), and Beclin-1 protein expression (Western blot). Results: The relative expressions of miR-216a in the osteosarcoma tissues significantly exceeded their expressions in the paracancerous normal tissues (P<0.05). The relative expression of miR-216a in the inhibitor group was notably lower than it was in the no-treatment control group and the negative control group (P<0.05). The difference in the relative expression levels of miR-216a in the blank control group and the negative control group showed no statistical significance (P>0.05). The absorbance value of the cells in the miR-216a inhibitor group at 48 h, 72 h, and 96 h at OD490 was significantly lower than it was in the no-treatment control group and negative control group (P<0.05), and there was no significant difference in the absorbance value at 490 nm in the no-treatment control group or the negative control group at each time point (P>0.05). The number of cells penetrating the basement membrane of the miR-216a inhibitor group was apparently less than it was in the no-treatment control group and the negative control group (P<0.05), and the difference between the no-treatment control group and the negative control group was not statistically significant (P>0.05). After 12 hours of scratch treatment on each group of cells, the migration force of the osteosarcoma cells in the miR-216a inhibitor group was significantly weaker than it was in the negative control group and the no-treatment control group, but the migration force in the negative control group and the no-treatment control group was not significantly changed. The relative expression degree of the Beclin-1 protein in the osteosarcoma cells in the miR-216a inhibitor group was much higher than it was in the no-treatment control group and the negative control group (P<0.05), but the difference showed no statistical significance between the relative expression degrees of the Beclin-1 protein in the no-treatment control group and the negative control group (P>0.05). Conclusion: The expression of miR-216a in the osteosarcoma tissue increased abnormally. Inhibiting its expression helps to restrain the proliferation in osteosarcoma cells, reduce the invasion and migration abilities of the osteosarcoma cells, and accelerate the autophagy of the osteosarcoma cells, which provides a new, prospective biological direction for curing osteosarcoma.