OBJECTIVE

To probe into the expression of FGD5-AS1 in osteosarcoma and its relationship with miR-320b.

METHODS

The tissue and serum samples of 97 patients with osteosarcoma were collected, and the serum samples of 100 healthy subjects who concurrently underwent physical examination were selected as the control. FGD5-AS1 expression in tissues and serum was detected, and osteosarcoma cells were transfected to measure cell behaviors such as proliferation, invasion and apoptosis.

RESULTS

FGD5-AS1 was highly expressed in osteosarcoma, and its elevated expression indicated poor survival of patients. Serum FGD5-AS1 was related to tumor size and clinical stage and could be used for the diagnosis of osteosarcoma. The study of osteosarcoma cell lines U2OS and SaOS-2 showed that after inhibiting FGD5-AS1, the viability and invasion capacity of osteosarcoma cells decreased statistically compared with the control group (CG), while the apoptosis ability could be improved by further regulating apoptotic proteins (P<0.05). Detection of EMT-related proteins identified that E-cadherin increased while N-cadherin decreased significantly after FGD5-AS1 inhibition (P<0.05). Correlation analysis revealed a negative correlation between miR-320b and FGD5-AS1 (r = -0.410, P<0.001). Overexpression of miR-320b significantly inhibited cell viability, invasion and EMT ability, and increased the apoptosis rate, while inhibiting miR-320b expression produced the opposite results. The targeting relationship between miR-320b and FGD5-AS1 was confirmed through the biological prediction website, luciferase assay and RNA binding protein immunoprecipitation (RIP) assay. Inhibition of miR-320b could reverse the regulatory effect of FGD5-AS1 knockdown on osteosarcoma cells.

CONCLUSION

FGD5-AS1 is highly expressed in osteosarcoma and is involved in the biological procession of osteosarcoma by targeting miR-320b.