RNA secondary structured logic gates for profiling the microRNA cancer biomarkers

MiR-125b targeted regulation of MKNK2 inhibits multiple myeloma proliferation and invasion

BACKGROUND

An increasing number of studies demonstrate that abnormal miRNA expression contributes to the advancement of many tumors. Nonetheless, the potential role of miR-125b in multiple myeloma (MM) remains unknown.

OBJECTIVES

To explore the potential effects and mechanism of miR-125b in MM.

METHODS

Real-time quantitative PCR was used to measure the expression levels of miR-125b and MKNK2 in a variety of MM samples. Colony formation and cell counting Kit-8 (CCK-8) assays were used to assess cell proliferation, the transwell assay was used to evaluate the cell invasion capability, and dual luciferase reporter gene assay and Western blot were used to examine the interaction between miR-125b and MKNK2.

RESULTS

The levels of miR-125b were higher in MM tissue samples, alongside increased expression of MKNK2. There was a negative correlation between MKNK2 and miR-125b expression in MM tissues. MKNK2 was identified as a direct target gene of miR-125b in MM cells. Overexpression of miR-125b suppressed MM cell growth, colony formation, and invasion. In addition, MKNK2 was found to mediate the effects of miR-125b on cell proliferation, colony formation, and invasion in MM.

CONCLUSIONS

miR-125b acts as a suppressive factor in multiple myeloma and can affect the malignant behavior of MM by regulating the expression of MKNK2.

miR-451a targeting IL-6R activates JAK2/STAT3 pathway, thus regulates proliferation and apoptosis of multiple myeloma cells

OBJECTIVES

To investigate the effects of miR-451a targeting interleukin-6 (IL-6) on the proliferation and apoptosis of multiple myeloma (MM) cells and its potential mechanism via JAK2/STAT3 pathway.

METHODS

mRNA expression of miR-451a and IL-6R in the plasma of patients with MM and normal controls were determined by RT-qPCR. U266 cells were cultured, transfected with miR-451a mimics, the proliferative ability of U266 cells was determined by CCK-8. Potential targets of miR-451a were predicted with the biological software TargetScan, and the direct relationship between miR-451a and the target IL-6R was analyzed by a dual-luciferase reporter assay. U266 cells were stimulated with IL-6R (100 ng/ml), and the proliferative ability and apoptosis rate were determined by CCK-8 and flow cytometry after 48h.

RESULTS

In the plasma of patients with MM, miR-451a expression was low and IL-6R expression was high. miR-451a targeted and negatively regulated IL-6R. Overexpressing miR-451a inhibited the proliferation and promoted the apoptosis of U266 cells. IL-6R acting on U266 cells promoted the proliferation and inhibited the apoptosis of U266 cells. Overexpressing miR-451a inhibited the activation of JAK2/STAT3 pathway and down-regulating miR-451a promoted the activation of JAK2/STAT3 pathway.

CONCLUSIONS

miR-451a targeting IL-6R activates JAK2/STAT3 pathway, thus regulates the proliferation and apoptosis in MM cells.