miRNA-320a inhibits tumor proliferation and invasion by targeting c-Myc in human hepatocellular carcinoma

Abstract

BackgroundDownregulated expression levels of microRNA-320a (miR-320a) were found in primary breast cancers and colorectal cancer. Previous findings indicated that miRNA-320a may involve in the cancer development. In this study, we explored the roles of miR-320a by targeting c-Myc in the tumor growth of hepatocellular carcinoma (HCC).MethodsQuantitative reverse-transcription polymerase chain reaction (qRT-PCR) was performed to detect the expression of miR-320a in 50 HCC tissues and four HCC cells. Luciferase reporter assay was conducted to confirm the direct downstream target of miR-320a in HEK-293 cells. The effect of miR-320a on endogenous c-Myc expression was investigated by transfecting miR-320a mimics into HepG2 and QGY-7703 cell lines. The c-Myc and miR-320a expressions were analyzed by immunohistochemistry (IHC) and qRT-PCR in the same HCC tissues. Furthermore, the biological functional correlation of miR-320a with c-Myc was determined by studying the effect of miR-320a mimics or c-Myc small interfering RNA (siRNA) on HCC cell proliferation and invasion.ResultsThe expression of miR-320a was downregulated in 50 HCC tissues and 4 HCC cells. Luciferase assay revealed that c-Myc is a direct target of miR-320a. IHC and Western blot analysis showed that the c-Myc expression was inhibited by miR-320a in HCC tissues and cell lines. Upregulation of miR-320a suppressed the HCC cell proliferation and invasion capacity induced by inhibiting c-Myc, and the results were consistent with the effects of c-Myc siRNA on tumor suppression. These results revealed that miRNA-320a inhibits tumor proliferation and invasion by targeting c-Myc in HCC cells.ConclusionOur results showed that miR-320a functions as a tumor suppressor in HCC. By targeting c-Myc directly, miR-320a inhibits the HCC cell growth. Our studies provide evidence of miR-320a as a potentially target for HCC treatment.

Retracted: MicroRNA‐497 accelerates apoptosis while inhibiting proliferation, migration, and invasion through negative regulation of the MAPK/ERK signaling pathway via RAF‐1

“…The pathogenesis of CC is still not clear at present, though the infection of human papillomavirus (HPV) is correlated with CC; and HPV is not enough for promoting malignant transformation in the cervix, so other factors important for this process should be investigated (Dang, Zheng, Liu, Wu, & Wu, ; Liu, Liu, Guo, Liu, & Li, ). microRNAs (miRNAs) have been evinced to regulate tumor proliferation and invasion in cancers, and they are widely analyzed in diagnosis, therapies and prognosis of cancers (Kosaka, Iguchi, & Ochiya, ; Xie et al, ).…”

MicroRNA‑93‑5p promotes the progression of human retinoblastoma by regulating the PTEN/PI3K/AKT signaling pathway

“…Accumulating studies have also indicated that miRNAs may serve as oncogenes or tumor suppressors to regulate tumor cell proliferation, migration and invasion (11)(12)(13)(14). For instance, miRNA-320a inhibits tumor proliferation and invasion by targeting c-Myc in human hepatocellular carcinoma (15). Numerous miRNAs have been reported to regulate the progression of RB, including miR-29a (12), miR106b (13), miRNA-382 (16) and miRNA-320 (17); however, the functions of miRNAs in RB are yet to be determined and the roles of most miRNAs in RB remain unknown.…”

Circulating microRNA-34 family low expression correlates with poor prognosis in patients with non-small cell lung cancer

“…coding RNA molecules at length about 19 to 24 nucleotides, have established their value into multiple pathological processes, including cell proliferation, cell apoptosis and cell differentiation, through the post-transcriptional regulation of genes expression (6)(7)(8). Accumulating evidences disclose that several miRNAs act as important biomarkers for the diagnosis and prognosis of various cancers, such as NSCLC, pancreatic cancer and colorectal cancer (9)(10)(11).…”