Objective To observe the effect of microRNA-203b-3p (miR-203b-3p) on multiple myeloma (MM) cells by regulating tumor necrosis factor superfamily member 13b (TNFSF13B) and explore the related mechanism of miR-203b-3p in inhibiting MM.

Methods Real-time fluorescent quantitative polymerase chain reaction (qRT-PCR) and Western blot were used to detect the expressions of miR-203b-3p and TNFSF13B in MM tumors and cells. The relationship between miR-203b-3p and TNFSF13B was validated by dual luciferase reporter experiments. Lipofectamine 2000 reagent was used for transfection of MM cells. The effects of miR-203b-3p and TNFSF13B on the biological function of MM cells were analyzed by colony formation assay, scratch assay, and Transwell assay.

Results Compared with the cancer-adjacent tissues and normal cells, the expressions of miR-203b-3p in MM tissues and cells were relatively low, while the expression of TNFSF13B in MM tumors and cells was increased when compared with normal tissues and cells, and the differences were statistically significant (P < 0.05). The dual luciferase reporter experiment showed that TNFSF13B was the direct target of miR-203b-3p. Overexpression of miR-203b-3p in MM cells was able to inhibit cell proliferation and migration, while upregulation of TNFSF13B promoted MM cell proliferation, migration and invasion(P < 0.05).

Conclusion MiR-203b-3p may inhibit the proliferation, invasion and migration of MM cells by downregulating TNFSF13B.