CircRERE promotes proliferation, migration and invasion of human multiple myeloma cell lines by regulating miR-128-3p/WEE1 axis

Objective To investigate the impacts of circular RNA RERE (circRERE) on proliferation, migration and invasion of human multiple myeloma (MM) cell lines by regulating microRNA (miR)-128-3p/serine/threonine protein kinase (WEE1) axis. Methods Normal plasma cells (nPCs) isolated from peripheral blood of healthy subjects and human MM cell lines(U266, RPMI-8226, NCI-H929, LP-1) were cultured. The expressions of circRERE and miR-128-3p were detected by RT-qPCR. The expression of WEE1 was detected by Western blot. After transfection, RPMI-8226 cells were divided into control group (without transfection), sh-circRERE group, sh-NC group, miR-128-3p inhibitor group, inhibitor-NC group, sh-circRERE+inhibitor-NC group and sh-circRERE+miR-128-3p inhibitor group. MTT assay and 5-ethynyl-2'-deoxyuridine (EdU) immunofluorescence staining microscopy were used to detect the proliferation. Migration and invasion were examined by scratch healing experiment as well as Transwell chamber assay. The targeting relationship between miR-128-3p and circRERE or WEE1 was verified though dual-luciferase reporter gene assay. Results Compared with nPCs, the expressions of circRERE and WEE1 in MM cells (RPMI-8226, U266, NCI-H929, LP-1) were increased, and the expression of miR-128-3p was decreased (P＜0.05). Compared with the control group, the proliferation rate, proportion of EdU positive cells, the healing rate of the scratch trauma and the number of invasion of the RPMI-8226 cells in sh-circRERE group were decreased(P＜0.05). However,miR-128-3p inhibitor group showed an opposite result and the difference was statistically significant (P＜0.05). miR-128-3p inhibitor significantly inhibited the effects of sh-circRERE on the proliferation, migration and invasion of RPMI-8226 cells (P＜0.05). Dual luciferase reporter gene experiments showed that circRERE/miR-128-3p and miR-128-3p/WEE1 had a targeting relationship. Conclusions CircRERE may promote proliferation, migration and invasion of RPMI-8226 cells, potentially with a mechanism of regulating miR-128-3p/WEE1 axis.