Mechanism of miR-200b-3p-induced FOSL2 inhibition of endometrial cancer cell proliferation and metastasis
Authors: He# Lijie , Wang Jing , han zhe 
Published: September 2024

Objective The purpose of this study was to investigate how miR-200b-3p inhibits the proliferation and metastasis of endometrial cancer cells by inducing the expression of FOSL2 in the AP1 transcription family.
Methods Endometrial cancer cell line HEC-1-A was divided into 12 groups: NC-mimic ( transfected with negative control NC mimic ), miR-200b-3p mimic ( transfected with miR-200b-3p mimic ), NC-suppress ( transfected with negative control NC inhibit ), miR-200b-3p inhibit group ( transfected with miR-200b-3p inhibit ), si-NC ( transfected with negative control Si-NC ), Si-FOSL2 ( transfected with Si-FOSL2 ), oe-NC ( transfected with negative control oe-NC ), oe-FOSL2 group ( oe-FOSL2 ), MiR-200b-3p mimic + oe-NC group ( co-transfected with miR-200b-3p mimic and oe-NC ), miR-200b-3p mimic + oe-FOSL2 group ( co-transfected with miR-200b-3p mimic and oe-FOSL2 ), miR-200b-3p inhibit + si-NC group ( co-transfected with miR-200b-3p inhibit and si-NC ), miR-200b-3p inhibit + si-FOSL2 group ( co-transfected with miR-200b-3p inhibit and si-FOSL2 ). Real-time fluorescence quantitative PCR, Western blot, CCK-8 assay, scratch test and Transwell assay were used to detect the expression of miR-200b-3p mRNA, FOSL2 mRNA and protein, cell proliferation, migration and invasion.
Results In endometrial cancer cell lines, the expression of miR-200b-3p was significantly down-regulated (P<0.05), while the expression of FOSssL2 was significantly up-regulated (P<0.05). Compared with NC-mimic group, the expression of FOSL2, N-cadherin and Vimentin in miR-200b-3p mimic group was significantly decreased (P<0.05), and the expression of E-cadherin was significantly increased (P<0.05). The cell proliferation, migration rate and the number of transmembrane cells were significantly decreased (P<0.05). Compared with the miR-200b-3p mimic + oe-NC group, the expression of FOSL2, N-cadherin and Vimentin in miR-200b-3p mimic + oe-FOSL2 was significantly increased (P<0.05), the expression level of E-cadherin was significantly decreased (P<0.05), and the cell proliferation, migration rate and the number of transmembrane cells were significantly increased (P<0.05). Compared with NC-inhibit group, the expression of FOSL2, N-cadherin and Vimentin in miR-200b-3p inhibit group was significantly increased (P<0.05), and the expression of E-cadherin was significantly decreased (P<0.05). The cell proliferation, migration rate and the number of transmembrane cells were significantly increased (P<0.05). Compared with the miR-200b-3p inhibit + si-NC group, the expression of FOSL2, N-cadherin and Vimentin in miR-200b-3p inhibit + si-FOSL2 was significantly decreased (P<0.05), and the expression of E-cadherin was significantly increased (P<0.05); the cell proliferation, migration rate and the number of transmembrane cells were significantly decreased (P<0.05)
Conclusion The expression of miR-200b-3p in endometrial cancer cells is down-regulated, which can inhibit the proliferation, migration and invasion of endometrial cancer cells by regulating the EMT process, and its mechanism is related to its targeted negative regulation of FOSL2 expression.