MicroRNA-30b targets CBX3 and regulates cell proliferation, apoptosis, and migration in esophageal squamous cell carcinoma via the JAK2/STAT3 signaling pathway

The present study aimed to investigate whether miR-30b plays a pivotal role in the progression of esophagea squamous cell carcinoma (ESCC) as well as to elucidate its possible regulatory mechanism. The expression levels of miR-30b in the ESCC tissues and cells were determined. The TE-1 cells were transfected with the miR-30b mimic, the mimic control, the miR-30b inhibitor, the inhibitor control, the pCDNA3.1-Chromobox 3 (pCDNA3.1-CBX3) and/or the blank vector, while the TE-2 cells were transfected with the miR-30b mimic and/or the mimic control. Cell proliferation, cell apoptosis, and cell migration of the different transfected groups were evaluated. The luciferase reporter assay was performed to detect the relationship between miR-30b, and CBX3. Furthermore, the relationship between miR-30b, CBX3, and the JAK2/STAT3 signaling pathway was explored. Significant downregulation of miR-30b was observed in the ESCC tissues and cells, while CBX3 was upregulated in the ESCC tissues and cells. The inhibition of miR-30b promoted cell proliferation, inhibited cell apoptosis, and enhanced cell migration in ESCC, which was similar to the effects of CBX3 overexpression. In fact, CBX3 was confirmed to be a direct target of miR-30b. The overexpression of miR-30b decreased the expression levels of p-JAK2/JAK2 and p-STAT3/JAK3 significantly, which was obviously reversed after the simultaneous overexpression of CBX3. Our results revealed that the downregulation of miR-30b may increase cell proliferation, inhibit cell apoptosis, and promote cell migration in ESCC by targeting CBX3 and activating the JAK2/STAT3 signaling pathway. Thus, miR-30b may serve as a useful marker for predicting the progression of ESCC.