Clinicopathological significance of miR-27b targeting Golgi protein 73 in patients with hepatocellular carcinoma.

Using five bioinformatics analysis software, we identified Golgi protein 73 (GP73) as a putative target of microRNA-27b (miR-27b), which is closely related to various biological processes or diseases such as bone metabolism disease, adipose cell and muscle cell development, pulmonary hypertension, cervical cancer, and breast cancer. However, the clinical significance of miR-27b in hepatocellular carcinoma (HCC) is still unclear. The differential expression of miR-27b in HCC and adjacent normal liver tissues was measured by quantitative reverse transcription PCR. Our results showed that the expression of miR-27b in tumor tissues is lower than that in adjacent nontumor tissues. The expression of miR-27b was significantly lower in HCC tissues with high expression of GP73, when compared with adjacent nontumor tissues. Moreover, down-regulated expression of miR-27b was closely correlated with serum GP73, tumor-node-metastasis stage, tumor size, and portal vein thrombosis. GP73 mRNA might be a target of miR-27b. The 5-year overall survival rate of the low miR-27b expression group was significantly lower than that of the high miR-27b expression group. Moreover, multivariate analysis of prognostic factors, with a Cox proportional hazards model, showed that low miR-27b expression was a significant and independent predictor of poor survival in HCC. Hence, the abnormal expression of miR-27b might be related to the occurrence and development of tumors. Similarly, a study in the Cancer Genome Atlas database demonstrated that the expression of miR-27b in 50 normal individuals was 1.6 times higher than that of 372 patients with liver cancer. The overall survival rate of the low GP73 expression group (275 liver cancer patients) was significantly longer than that of the high GP73 expression group (90 normal individuals). MiR-27b suppresses the expression of GP73 and is therefore a potential prognostic biomarker and therapy target in HCC.

miR-449a: a potential therapeutic agent for cancer.

MicroRNAs (miRNAs) have been reported to be associated with cancer progression and carcinogenesis. They are small, highly conserved, noncoding RNA molecules consisting of 19-25 nucleotides. By binding to complementary binding sites within the 3'-untranslated region of target mRNAs, miRNAs inhibit the translation of mRNAs or promote their degradation. miRNAs play critical roles in cancer initiation and development by functioning either as oncogenes or as tumor suppressors. Similarly, several studies have shown that miRNAs are involved in regulating various biological processes, including apoptosis, proliferation, cellular differentiation, signal transduction, and carcinogenesis. Among miRNAs, one that may be of particular interest in cancer biology is miR-449a, which has been reported to inhibit tumor growth, invasion, and metastasis, and to promote apoptosis and differentiation through the transforming growth factor-ß activated kinase 1, NOTCH, nuclear factor-κB/P65/vascular endothelial growth factor, retinoblastoma-E2F, mitogen-activated protein kinase signaling pathways, WNT-ß-catenin signaling, tumor protein P53, and androgen receptor signaling pathways. The miR-449 cluster is located in the second intron of CDC20B on chromosome 5q11.2, a region that has been identified as a susceptibility locus in cancer, and the abnormal expression of miR-449a may be related to the occurrence and development of tumors. As one example, miR-449a has been reported to be involved in the development of carcinoma and may be a potential prognostic indicator. On the basis of the putative pathogenetic relationships between cancer and miR-449a, we consider that miR-449a has the potential to serve as a therapeutic agent for the treatment of some types of cancer. In this review, the role of miR-449a in tumorigenesis and its mechanism of action are explored. Furthermore, its potential as a therapeutic agent in cancer treatment is considered.