Figure 2.

Kinesin superfamily protein 4A (KIF4A) regulates osteosarcoma (OS) cell proliferation and apoptosis in vitro and in vivo.

(a) qPCR demonstrating successful shRNA-mediated knockdown of KIF4A in U2OS and MG63 cells. (b) Western blotting demonstrating successful shRNA-mediated knockdown of KIF4A in U2OS and MG63 cells. (c) Proliferation of KIF4A-knockdown cells (shKIF4A-1, shKIF4A-2) were significantly lower than that of the control cells (Vector) at 96 h (**p<0.01). (d) The number of clones of U2OS and MG63 cells with KIF4A-knockdown were significantly fewer than that of the control group in vitro (**p<0.01). (e, f) Significant apoptosis were detected in cisplatin (0.5 µM) -treated U2OS and MG63 cells(Vector vs. Vector+Cisplatin: ^##p<0.01). KIF4A knockdown enhanced cellular sensitivity to cisplatin (0.5 µM) -induced apoptosis in U2OS and MG63 cells (Vector+Cisplatin vs shKIF4A+Cisplatin: **p<0.01). (g) The expression levels of apoptosis-related proteins were measured by western blotting. Knockdown of KIF4A reduced phosphorylated AKT, BCL-2 expression and increased Bax expression in vitro. (h) Nude mice were inoculated subcutaneously with MG63 cells (Groups: Vector, shKIF4A; 5 × 10⁶ cells/animal; n=5; Time: 21 days) (i) Tumor growth curve showing that low expression of KIF4A inhibits tumor growth in vivo (**p<0.01). (j) Tumor weight measurements showing that the xenograft tumor weight in the group with KIF4A-knockdown (shKIF4A) was lower than the control group (Vector) in vivo(**p<0.01).