Double-targeted knockdown of miR-21 and CXCR4 inhibits malignant glioma progression by suppression of the PI3K/AKT and Raf/MEK/ERK pathways

Abstract

Background: Currently, miR-21 and CXCR4 are being extensively investigated as two unrelated key regulators in glioma malignancy. In this study, we investigated the combined effect of these two factors on glioma progression. Methods:We confirmed the expression of miR-21 and CXCR4 in malignant glioma tissue and glioma cells with qRT-PCR and western blotting. Single-targeted knockdown of miR-21 and CXCR4, as well as double-targeted knockdown of miR-21 and CXCR4 lentiviral vectors were constructed and they were transfected to U87 and U251 cells. Cell proliferation, apoptosis, invasion, and migration from different treatment groups were assessed by MTT assay, Flow Cytometry analysis, Transwell analysis, and Scratch assay, respectively. U87 xenograft mice were constructed to detect roles and potential mechanisms of miR-21 and CXCR4 in malignant glioma tumor growth. Results:The expression of miR-21 and CXCR4 was increased in tumor tissues and cell lines. Inhibition of miR-21, CXCR4, and miR-21 and CXCR4 together all reduced the migration, invasiveness, proliferation and enhanced apoptosis in glioma cells, as well as reduced tumor volume and mass in xenograft model. The inhibition effect was strongest in double-targeted knockdown of miR-21 and CXCR4 group, whose downstream pathways involved in AKT axis and ERK axis activation. Conclusions:Our findings reported that double-targeted knockdown of miR-21 and CXCR4 could more effectively inhibit the proliferation, migration, invasion and growth of transplanted tumor and promote cell apoptosis, which were involved in the PI3K/AKT and Raf/MEK/ERK signaling pathways.

Knockdown of ER‐α36 expression inhibits glioma proliferation, invasion and epithelial‐to‐mesenchymal transition

“…Previous studies have reported that both the PI3K/ AKT and MEK/ERK pathways are constitutively upregulated in glioma cells, which contributes to the unrestricted growth and enhanced invasion of glioma (Liu & Yang, 2020;Loh et al, 2019). Moreover, the activation of these pathways has been confirmed to play an important role in the progression of EMT (Guo, Yao, Zhang, & Bo, 2013;Song et al, 2014).…”

Fraxetin exerts anticancer effect in glioma by suppressing MiR‐21‐3p

“…MiR‐21 can also increase the expression of cyclin E1 and cyclin D1 in lung cancer cells, and increase the expression of CDK6 in laryngeal squamous cell carcinoma (Dai et al, 2019; Lyu et al, 2019). Of note, inhibition of miR‐21 expression in glioma has been proved to inhibit the progression of glioma (Guan et al, 2020; Liu & Yang, 2020). Consistent with previous research, we found that FXT suppressed cell viability and promoted apoptosis in glioma by downregulating miR‐21‐3p.…”

Study On the Mechanism of LMP2A Maintaining Epstein-barr Virus Latency Infection Through Interaction With CXCR4

“…At the same time, we also transfected ERK1/2-siRNAs into EBV positive gastric cancer cells, and the result was the same as that of adding inhibitors. The results of Liu et al showed that the doubletarget knockout of miR-21 and CXCR4 could more effectively inhibit the proliferation, migration, invasion and growth of glioma, and promote cell apoptosis, which may be related to PI3K/AKT and Raf/MEK/ERK signaling pathways [14]. CXCR4-ERK signaling pathway mediates proliferation, migration, and invasion of cancer cells in multiple types of tumors [2,15,18].…”