miR-374a promotes cell proliferation, migration and invasion by targeting SRCIN1 in gastric cancer

MiR-346 promotes the biological function of breast cancer cells by targeting SRCIN1 and reduces chemosensitivity to docetaxel

MicroRNAs (miRNAs) are a class of highly conserved small noncoding RNAs that play pivotal roles at the post-transcriptional level in the biological function of various cancers, including breast cancer. In our study, miR-346 mimic, inhibitor, negative control or si-SRCIN1 were transfected into MCF-7 and MCF-7/Doc cells, respectively. Quantitative real time PCR (qRT-PCR) was used to measure miR-346 and SRCIN1 mRNA expressions and western blot was used to detect the expression of SRCIN1 in protein level. CCK-8 and colony formation were employed to verify cell viability and proliferation. Flow cytometry showed the apoptosis. Transwell was performed to detect migration and invasion. The luciferase reporter assay data showed the target correlation of miR-346 and SRCIN1. Firstly, we found that the expression of miR-346 was higher in breast cancer tissues than in their paired corresponding non-cancerous tissues and there was significant inversed correlation between miR-346 and SRCIN1. Overexpression of miR-346 promoted cell proliferation, colony formation, migration and invasion, and reduced apoptosis, sensitivity to Docetaxel (Doc). SRCIN1 was identified as a direct target of miR-346, whose silencing promoted cell proliferation and the IC50 of Doc. Moreover, SRCIN1 silencing reduced the effect of miR-346 down-expression. Taken together, miR-346 may function as an oncogenic miRNA and mediate chemosensitivity to docetaxel through targeting SRCIN1 in breast cancer, targeted modulation of miR-346 expression may became a potential strategy for the treatment.

MiR-374a suppresses lung adenocarcinoma cell proliferation and invasion by targeting TGFA gene expression

Aberrant expression of miR-374a has been reported in several types of human cancers, including lung cancer. However, the functional significance and molecular mechanisms underlying the role of miR-374a in lung cancer remain largely unknown. We found that the expression of miR-374a was significantly downregulated in lung adenocarcinoma tissues compared to adjacent normal lung tissues in samples included in The Cancer Genome Atlas. Functional studies revealed that overexpression of miR-374a led to inhibition of lung adenocarcinoma cell proliferation, migration and invasion and that miR-374a negatively regulated transforming growth factor-alpha (TGFA) gene expression by directly targeting the 3'-UTR of TGFA mRNA. Treating lung adenocarcinoma cells with TGF-α neutralizing antibody resulted in suppression of cell proliferation and invasion, which mimicked the action of miR-374a. Additionally, TGFA gene expression was significantly higher in tumor tissues compared to adjacent normal tissue and high TGFA gene expression strongly correlated with poor survival in patients with lung adenocarcinoma. Taken together, our studies suggest that miR-374a suppresses lung adenocarcinoma cell proliferation and invasion via targeting TGFA gene expression. Our findings may provide novel treatment strategies for lung adenocarcinoma patients.

miR-448 suppressed gastric cancer proliferation and invasion by regulating ADAM10

MicroRNAs (miRNAs) are a class of short, noncoding RNAs that act a crucial role in tumor development. Previous studies showed that miR-448 expression was deregulated in many tumors. However, the role of miR-448 in gastric cancer (GC) remains unknown. In our study, we demonstrated that miR-448 expression was downregulated in GC tissues compared with the corresponding nontumor tissues. We also showed that miR-448 expression was downregulated in GC cell lines. Ectopic expression of miR-448 suppressed GC cell proliferation, colony formation, and invasion. Moreover, we identified A Disintegrin And Metalloproteinases 10 (ADAM10) as a direct target gene of miR-448 in GC cell. ADAM10 expression was upregulated in GC tissues and cells. Furthermore, the expression level of miR-448 was negatively correlated with the expression level of ADAM10 in GC tissues. Moreover, ADAM10 overexpression rescued the effect of miR-448-mediated GC cell proliferation, colony formation, and invasion. These results demonstrated that miR-448 might play as a tumor suppressor miRNA partly through targeting ADAM10 expression.

Emerging roles of non-coding RNAs in gastric cancer: Pathogenesis and clinical implications

Gastric cancer is a leading cause of cancer-related deaths. However, the mechanisms underlying gastric carcinogenesis remain largely unclear. The association of non-coding RNAs (ncRNAs) with cancer has been widely studied during the past decade. In general, ncRNAs have been classified as small ncRNAs, including microRNAs (miRNAs), and long non-coding RNAs (lncRNAs). Emerging evidence shows that miRNAs and lncRNAs play key roles in the formation and progression of many cancers. In this review, we focus on the regulation of miRNAs and lncRNAs in gastric cancer. miRNAs and lncRNAs appear to be involved in gastric tumor growth, invasion, and metastasis and in establishment of the gastric tumor microenvironment through various mechanisms. Furthermore, we also discuss the possibilities of establishing miRNAs and lncRNAs as potential biomarkers and therapeutic targets for gastric cancer. Taken together, we summarize the emerging roles of ncRNAs in gastric cancer development and their possible clinical significance.

miR-599 Inhibits Vascular Smooth Muscle Cells Proliferation and Migration by Targeting TGFB2

Aberrant proliferation and migration of vascular smooth muscle cells (VSMCs) play a crucial role in the pathogenesis of cardiovascular diseases including coronary heart disease, restenosis and atherosclerosis. MicroRNAs are a class of small, non-coding and endogenous RNAs that play critical roles in VSMCs function. In this study, we showed that PDGF-bb, as a stimulant, promoted VSMCs proliferation and suppressed the expression of miR-599. Moreover, overexpression of miR-599 inhibited VSMCs proliferation and also suppressed the PCNA and ki-67 expression. In addition, we demonstrated that ectopic expression of miR-599 repressed the VSMCs migration. We also showed that miR-599 inhibited type I collagen, type V collagen and proteoglycan expression. Furthermore, we identified TGFb2 as a direct target gene of miR-599 in VSMCs. Overexpression of TGFb2 reversed miR-599-induced inhibition of VSMCs proliferation and type I collagen, type V collagen and proteoglycan expression. In conclusion, our findings suggest miR-599 plays a crucial role in controlling VSMCs proliferation and matrix gene expression by regulating TGFb2 expression.

Dysregulation of non-coding RNAs in gastric cancer

Gastric cancer (GC) is one of the most common cancers in the world and a significant threat to the health of patients, especially those from China and Japan. The prognosis for patients with late stage GC receiving the standard of care treatment, including surgery, chemotherapy and radiotherapy, remains poor. Developing novel treatment strategies, identifying new molecules for targeted therapy, and devising screening techniques to detect this cancer in its early stages are needed for GC patients. The discovery of non-coding RNAs (ncRNAs), primarily microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), helped to elucidate the mechanisms of tumorigenesis, diagnosis and treatment of GC. Recently, significant research has been conducted on non-coding RNAs and how the regulatory dysfunction of these RNAs impacts the tumorigenesis of GC. In this study, we review papers published in the last five years concerning the dysregulation of non-coding RNAs, especially miRNAs and lncRNAs, in GC. We summarize instances of aberrant expression of the ncRNAs in GC and their effect on survival-related events, including cell cycle regulation, AKT signaling, apoptosis and drug resistance. Additionally, we evaluate how ncRNA dysregulation affects the metastatic process, including the epithelial-mesenchymal transition, stem cells, transcription factor activity, and oncogene and tumor suppressor expression. Lastly, we determine how ncRNAs affect angiogenesis in the microenvironment of GC. We further discuss the use of ncRNAs as potential biomarkers for use in clinical screening, early diagnosis and prognosis of GC. At present, no ideal ncRNAs have been identified as targets for the treatment of GC.

Next generation sequencing profiling identifies miR-574-3p and miR-660-5p as potential novel prognostic markers for breast cancer

Background

Prognostication of Breast Cancer (BC) relies largely on traditional clinical factors and biomarkers such as hormone or growth factor receptors. Due to their suboptimal specificities, it is challenging to accurately identify the subset of patients who are likely to undergo recurrence and there remains a major need for markers of higher utility to guide therapeutic decisions. MicroRNAs (miRNAs) are small non-coding RNAs that function as post-transcriptional regulators of gene expression and have shown promise as potential prognostic markers in several cancer types including BC.

Results

In our study, we sequenced miRNAs from 104 BC samples and 11 apparently healthy normal (reduction mammoplasty) breast tissues. We used Case–control (CC) and Case-only (CO) statistical paradigm to identify prognostic markers. Cox-proportional hazards regression model was employed and risk score analysis was performed to identify miRNA signature independent of potential confounders. Representative miRNAs were validated using qRT-PCR. Gene targets for prognostic miRNAs were identified using in silico predictions and in-house BC transcriptome dataset. Gene ontology terms were identified using DAVID bioinformatics v6.7. A total of 1,423 miRNAs were captured. In the CC approach, 126 miRNAs were retained with predetermined criteria for good read counts, from which 80 miRNAs were differentially expressed. Of these, four and two miRNAs were significant for Overall Survival (OS) and Recurrence Free Survival (RFS), respectively. In the CO approach, from 147 miRNAs retained after filtering, 11 and 4 miRNAs were significant for OS and RFS, respectively. In both the approaches, the risk scores were significant after adjusting for potential confounders. The miRNAs associated with OS identified in our cohort were validated using an external dataset from The Cancer Genome Atlas (TCGA) project. Targets for the identified miRNAs were enriched for cell proliferation, invasion and migration.

Conclusions

The study identified twelve non-redundant miRNAs associated with OS and/or RFS. These signatures include those that were reported by others in BC or other cancers. Importantly we report for the first time two new candidate miRNAs (miR-574-3p and miR-660-5p) as promising prognostic markers. Independent validation of signatures (for OS) using an external dataset from TCGA further strengthened the study findings.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1899-0) contains supplementary material, which is available to authorized users.

MicroRNA-346 functions as an oncogene in cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) is an epidermal keratinocyte-derived skin tumor, which is the second most common skin cancer in the general population. Recently, studies showed that microRNAs (miRNAs) played an important role in the development of cancer. In our study, we showed that the expression of SRCIN1 was lower in cSCC tissues than in the matched normal tissues. Moreover, there was significant inversed correlation between miR-346 and SRCIN1 in cSCC tissues. The luciferase reporter assay data showed that miR-346 can target the SRCIN1 message via the 3'-untranslated region (UTR) of SRCIN1. Overexpression of miR-346 inhibited the messenger RNA (mRNA) and protein expression of SRCIN1 in the A431 cells. In addition, ectopic expression of miR-346 promoted the A431 cell proliferation and migration. Meanwhile, SRCIN1 overexpression inhibited the A431 cell proliferation and migration. Rescue experiment has showed that SRCIN1 overexpression reduced the miR-346-induced A431 cell proliferation and migration. Herein, this study may provide miR-346 as a new therapeutic target for cSCC.

miR-211 promotes non-small cell lung cancer proliferation by targeting SRCIN1

MicroRNAs (miRNAs) are a class of small non-coding RNAs that, when dysregulated, are involved in the initiation and progression of various cancers, including lung cancer, in humans. In the current study, qRT-PCR was performed to measure miR-211 expression in human non-small cell lung cancer (NSCLC) cell lines and tissues. Cell proliferation, cell cycle, colony formation, and invasion were performed to detect the functional role of miR-211 in human NSCLC cell line. We used luciferase reporter assay to find the potential target of miR-211. We found that miR-211 expression was upregulated in human non-small cell lung cancer (NSCLC) cell lines and tissues. The overexpression of miR-211 enhanced NSCLC cell proliferation, colony formation, and invasion. SRC kinase signaling inhibitor 1 (SRCIN1) was identified as a direct target of miR-211. SRCIN1 silencing promoted cell proliferation, and SRCIN1 expression was downregulated in human NSCLC cell lines. Thus, miR-211 may function as an oncogenic miRNA in NSCLC, partly by regulating SRCIN1, and the modulation of miR-211 expression represents a potential strategy for the treatment of NSCLC patients.