Effects of microRNA-26b on proliferation and invasion of glioma cells and related mechanisms

Abstract

Neuroglioma is the most common primary malignant tumor in neurosurgery. Due to its short survival period and high patient mortality rate, neuroglioma is a major challenge in clinics. Elucidating the pathogenic mechanisms and associated molecular targets of neuroglioma can therefore benefit diagnosis and treatment of glioma. Previous studies have established the role of microRNA (miR)‑26b in various tumors, including breast cancer, lymphoma and glioma. Its function and mechanism in neuroglioma, however, remains to be elucidated. In the present study, in vitro cultured U87 glioma cells were randomly divided into miR‑26b mimic, miR‑26b inhibitor and respective control (NC) groups. MTT assay was performed to detect the effect of miR‑26b on cell proliferation, while a cell invasion assay detected its effects on cell invasion. Caspase‑3 activity was also quantified to test cell apoptosis, followed by reverse transcription-quantitative polymerase chain reaction and western blotting to detect the variation of Bcl‑2 expression under the effect of miR‑26b. miR‑26b mimics transfection upregulated its expression in U87 cells, which had significantly reduced Bcl‑2 mRNA and protein expression levels and higher casapse3 activity, and inhibited cell proliferation and invasion compared with the control group. The transfection of miR‑26b inhibitor, in contrast, facilitated U87 cell proliferation and invasion, inhibited caspase‑3 activity and elevated Bcl‑2 mRNA/protein expression. In conclusion, miR‑26 could facilitate apoptosis and inhibit proliferation/invasion of neuroglioma cells via downregulating Bcl‑2 expression and potentiating caspase-3 activity.

The effects of melatonin on signaling pathways and molecules involved in glioma

“…Even some miRNAs can have anti‐tumor effects. For example, miR‐26 could facilitate apoptosis and inhibit invasion/proliferation of neuroglioma cells via potentiating caspase‐3 activity and downregulating expression of Bcl‐2 . Change in miRNA expression can lead to disturbance in the expression of target protein, inhibition of the expression of tumor suppressor genes, or impairment in cellular processes .…”

“…About 15% of all brain tumors are diagnosed as GBMs, and affects three people per 100 000 annually . Among the malignant tumors of nervous system, GBM has a bad prognosis and creates many economic and psychological problems for patients and families . Some studies point to the effect of hereditary susceptibility and environmental oncogenic agents on the development of GBM .…”

RAB31 is targeted by miR-26b and serves a role in the promotion of osteosarcoma

“…Previously, miR-26b has been reported to function as a tumor suppressor (20)(21)(22)(23). Li et al (22) reported that miR-26b inhibits the metastasis of colorectal cancer by inhibiting fucosyltransferase 4. miR-26b has also been identified to inhibit proliferation and invasion of neuroglioma cells by downregulating Bcl-2 expression and enhancing caspase-3 activity (23). In OS, miR-26b has been reported to suppress cancer cell proliferation, migration and invasion, and induce OS cell apoptosis by inhibiting glycolysis (20).…”