MicroRNA-154: A Novel Candidate for Diagnosis and Therapy of Human Cancers

MicroRNAs (miRNAs) are endogenous, non-coding, single-stranded, tiny RNAs with 21–23 nucleotides that regulate several biological functions through binding to target mRNAs and modulating gene expression at post-transcriptional levels. Recent studies have described crucial roles for miRNAs in pathophysiology of numerous human cancers. They can act as an oncogene and promote cancer or as a tumor suppressor and alleviate the disease. Recently discovered microRNA-154 (miR-154) has been proposed to be involved in multiple physiological and pathological processes including cancer. With this aspect, aberrant expression of miR-154 has been demonstrated in variety of human malignancies, suggesting an important role for miR-154 in tumorigenesis. To be specific, it is considered as a tumor suppressor miRNA and exerts its beneficial effects by targeting several genes. This review systematically summarizes the recent advances done on the role of miR-154 in different cancers and discusses its potential prognostic, diagnostic and therapeutic values.

MicroRNA-154 functions as a tumor suppressor in non-small cell lung cancer through directly targeting B-cell-specific Moloney murine leukemia virus insertion site 1

Lung cancer remains the leading cause of cancer-associated mortality in China and worldwide. Increasing numbers of studies have demonstrated that microRNAs (miRNAs/miRs) have vital functions in numerous developmental processes and tumorigenesis. The aim of the present study was to investigate miR-154 expression in non-small cell lung cancer (NSCLC), and to explore the roles of miR-154 in the carcinogenesis and progression of this cancer. Reverse transcription-polymerase chain reaction (RT-qPCR) was performed to detect miR-154 expression in NSCLC tissues and cell lines. In addition, cell proliferation assay, migration and invasion assays were adopted to investigate the functional roles of miR-154 in NSCLC. Bioinformatics analysis, luciferase reporter assay, RT-qPCR and western blot analysis were used to explore the potential targets of miR-154 in NSCLC. According to the results, miR-154 was significantly downregulated in NSCLC tissues and cell lines. Restoration of miR-154 expression inhibited proliferation, migration and invasion of NSCLC cells. In addition, B-cell-specific Moloney murine leukemia virus insertion site 1 (BMI-1) was identified as a direct target gene of miR-154 in NSCLC. In conclusion, miR-154 may function as a tumor suppressor in NSCLC, partly by regulating BMI-1, and the modulation of miR-154 expression represents a potential strategy for the treatment of NSCLC patients.

MicroRNA-154/ADAM9 axis inhibits the proliferation, migration and invasion of breast cancer cells

Breast cancer is the leading cause for cancer-associated mortality in women. Although great progress has been made in the earlier diagnosis and systemic therapy of patients with breast cancer in recent years, recurrence or distant metastasis continue to present major barriers to the successful treatment of breast cancer. Therefore, fully understanding the molecular mechanisms underlying the progression of breast cancer may be critical for the development of effective therapeutic strategies against breast cancer. The aim of the present study was to explore the expression, function and molecular mechanisms of microRNA-154 (miR-154) in human breast cancer. It was demonstrated that miR-154 was significantly downregulated in breast cancer tissue and cell lines. The restoration of miR-154 expression suppressed the proliferation, migration and invasion of breast cancer cells. ADAM metallopeptidase domain 9 (ADAM9) was identified as a novel direct target for miR-154 in breast cancer. It was demonstrated that miR-154 acted as a tumor suppressor in breast cancer by targeting ADAM9. The results of the present study suggest that the restoration of miR-154 expression may be an effective therapeutic strategy for the treatment of breast cancer in the future.

MicroRNA-154 inhibits the growth and metastasis of gastric cancer cells by directly targeting MTDH

MicroRNAs (miRNAs) are a group of non-protein-coding, highly conserved single-stranded RNA molecules. The abnormal expression of miRNAs has been demonstrated to have an important function in the carcinogenesis and progression of gastric cancer. microRNA-154 (miR-154) has been reported to be downregulated in non-small cell lung, colorectal and prostate cancer. However, the expression and roles of miR-154 in gastric cancer remain to be established. The present study measured the expression levels of miR-154 in gastric cancer tissues and cell lines. miR-154 was found to be significantly downregulated in gastric cancer tissues and cell lines. In addition, functional studies indicated that the overexpression of miR-154 inhibited the proliferation, migration and invasion of gastric cancer cells. Using TargetScan, a dual luciferase reporter assay, reverse transcription-quantitative polymerase chain reaction and western blot analysis, metadherin (MTDH) was revealed as a novel miR-154 target. In addition, knocking down MTDH lead to a similar effect as overexpressing-154 in gastric cells. The present findings indicate that miR-154 was downregulated in gastric cancer, and inhibited tumor behaviors of gastric cancer cells partially through the downregulation of MTDH. Therefore, the miR-154/MTDH axis may be a novel therapeutic to treat patients with gastric cancer.