Expression and clinical significance of miRNAs that may be associated with the FHIT gene in breast cancer

CREB1 acts via the miR‑922/ARID2 axis to enhance malignant behavior of liver cancer cells

There is little information on the role of microRNA (miR)‑922 in the malignant behavior of liver cancer. The present study investigated the regulation of miR‑922 expression levels by cAMP response element binding protein 1 (CREB1) in liver cancer tissue, its role in regulating malignant behavior and its potential targets in liver cancer. miR‑922 expression in liver cancer cells and tissue was determined by reverse transcription‑quantitative PCR. The binding of CREB1 to the promoter region of mir‑922 was tested by chromatin immunoprecipitation‑PCR. The predicted AT‑rich interactive domain 2 (ARID2) and fidgetin, microtubule severing factor targets of miR‑922 were characterized by dual luciferase reporter assay. The effects of altered ARID2 expression levels on miR‑922‑enhanced malignant behavior of liver cancer cells were tested. CREB1 bound to the promoter region of miR‑922. Elevated miR‑922 transcripts were inversely associated with ARID2 expression in liver cancer tissue and cells. miR‑922 inhibited ARID2‑regulated luciferase expression and was present in the miR/argonaute RISC catalytic component 2 complex. ARID2 significantly decreased malignant behavior of liver cancer MHCC97L cells. Similarly, ARID2 over‑expression inhibited growth of xenograft liver cancer tumors and decreased miR‑922, Bcl‑2, proliferating cell nuclear antigen, cyclin D1, MMP3 and MMP9 expression and serum VEGF and TNF‑α levels, but enhanced Bax expression levels in tumors. ARID2 over‑expression abrogated malignant behavior promoted by miR‑922 over‑expression and enhanced miR‑922‑decreased malignant behavior of liver cancer cells. CREB induced miR‑922 transcription, which targeted ARID2 to enhance malignant behavior of liver cancer cells, indicating that the CREB1/miR‑922/ARID2 axis may be a potential target for liver cancer treatment.

Low Expression of miR-663a Indicates Poor Prognosis and Promotes Cell Proliferation, Migration, and Invasion in Breast Cancer

INTRODUCTION

Breast cancer is one of the most common malignant cancers among women worldwide. MicroRNA-663a (miR-663a) acts as a tumor suppressor gene involved in the development of various cancers.

OBJECTIVE

The aim of this study was to reveal the clinical significance and biological function of miR-663a in breast cancer.

METHODS

The expression of miR-663a in breast cancer tissues and cells was evaluated by reverse transcription-quantitative polymerase chain reaction. Kaplan-Meier survival and Cox regression analysis were performed to evaluate the prognostic significance of miR-663a in breast cancer. CCK-8 and Transwell assays were used to demonstrate the effect of miR-663a on breast cancer cell function.

RESULTS

We confirmed that the expression of miR-663a was significantly downregulated in breast cancer tissue samples and cell lines. Low miR-663a expression was significantly associated with lymph node metastasis, TNM stage, subtypes, and poor survival in breast cancer patients, indicating that miR-663a is an independent prognostic factor for patients with breast cancer. Cell function experiments revealed that low miR-663a expression promoted cell proliferation, migration, and invasion in breast cancer.

CONCLUSIONS

All experimental results demonstrated that miR-663a acts as a tumor suppressor that inhibits the proliferation, migration, and invasion of breast cancer cells, and miR-663a may be a prognostic biomarker and therapeutic target for breast cancer.

FOXC1-induced LINC01123 acts as a mediator in triple negative breast cancer

Background

MicroRNAs (miRNAs) representing a subclass of non-coding RNAs are dynamically expressed and participate in multiple pathological responses, whereas, the expression pattern or function of miRNAs has not been fully addressed in triple-negative breast cancer (TNBC). Currently we concentrate on dissecting the probable role of microRNA-663a (miR-663a) in TNBC cellular processes.

Methods

qRT-PCR detected the expression of miR-663a in TNBC cells. Besides, we monitored the effects of miR-663a on TNBC proliferation and apoptosis. On the basis of bioinformatics assistance and mechanical validation, we identified the miRNA-sponging role of LINC01123 and downstream target of miR-663a in TNBC was assessed and verified. The transcription activation of was explored via ChIP and luciferase reporter assays.

Results

In comparison to MCF-10A, we certified the downregulation of miR-663a in TNBC cell lines. Augmentation of miR-663a was anti-proliferation and pro-apoptosis in TNBC cell lines. LINC01123 protected CMIP against miR-663a suppression through acting as a sponge of miR-663a in TNBC. LINC01123 was transcriptionally induced by FOXC1. Rescue experiment proved that miR-663a suppression or CMIP (c-Maf inducing protein) enhancement could countervail LINC01123 depletion-mediated effects on TNBC cellular processes.

Conclusion

LINC01123, activated by FOXC1, regulated TNBC growth through miR-663a/CMIP signaling, which unveiled a new functional pathway of FOXC1-induced LINC01123/miR-663a/CMIP in TNBC.

miR-922 regulates apoptosis, migration, and invasion by targeting SOCS1 in gastric cancer

Gastric cancer (GC) is the second leading cause of cancer-related death worldwide. Studies have shown that miR-922 facilitates the development of various diseases and tumors. However, the role of miR-922 in GC and related molecular mechanisms are still unrevealed. Current study indicated that miR-922 was overexpressed in GC tissues and cells. The survival rate of patients in high miR-922 expression group is significantly lower than that in low miR-922 expression group. In addition, overexpression of miR-922 observably restrained the apoptosis of SGC7901 cells and promoted SGC7901 cell proliferation, migration, and invasion. TargetScan predicted that suppressors of cytokine signaling 1 (SOCS1) was a potential target of miR-922. miR-922 upregulation profoundly inhibited the expression of SOCS1. Furthermore, the mRNA level of SOCS1 in GC tissues was significantly lower than that in adjacent tissues, indicating that miR-922 promoted the proliferation, invasion, and migration, and inhibited apoptosis of SGC7901 cells by downregulating the level of SOCS1. In conclusion, miR-922 may have potential for diagnosis of GC.

A six-microRNA signature to predict outcomes of patients with gastric cancer

Gastric cancer (GC) is a common gastrointestinal tumor with poor prognosis. However, conventional prognostic factors cannot accurately predict the outcomes of GC patients. Therefore, there remains a need to identify novel predictive markers to improve prognosis. In this study, we obtained microRNA expression profiles of 385 GC patients from The Cancer Genome Atlas. We performed Cox regression analysis to identify overall survival‐related microRNA and then constructed a microRNA signature‐based prognostic model. The accuracy of the model was evaluated and validated through Kaplan–Meier survival analysis and time‐dependent receiver operating characteristic (ROC) curve analysis. The independent prognostic value of the model was assessed by multivariate Cox regression analysis. Enrichment analysis was performed to explore potential functions of the prognostic microRNA. Finally, a prognostic model based on a six‐microRNA (miRNA‐100, miRNA‐374a, miRNA‐509‐3, miRNA‐668, miRNA‐549, and miRNA‐653) signature was developed. Further analysis in the training, test, and complete The Cancer Genome Atlas set showed the model can distinguish between high‐risk and low‐risk patients and predict 3‐year and 5‐year survival. The six‐microRNA signature was also an independent prognostic marker, and enrichment analysis suggested that the microRNA may be involved in cell cycle and mitosis. These results demonstrated that the model based on the six‐microRNA signature can be used to accurately predict the prognosis of GC patients.

Oncogenic miR-663a is associated with cellular function and poor prognosis in renal cell carcinoma

BACKGROUND

MicroRNA(miRNA) plays a key regulatory role in various stages of tumorigenesis, including cell growth, cell cycle control, apoptosis avoidance, tissue invasion, and metastasis. Several microRNAs are involved in the development of renal cell carcinoma (RCC) and the malignant transformation process. However, the effects of miR-663a on RCC have rarely been reported.

METHODS

In the present study, the expression of miR-663a was examined in RCC using matched normal kidney tissues and four cell lines (786-O, Caki-1, ACHN and HK-2). MicroRNA mimics were transiently transfected into RCC cells and the effects of over expression on proliferation, migration, invasion, and apoptosis was observed. In addition, the relationship between miR-663a expression in 42 formalin-fixed paraffin-embedded (FFPE) clear cell renal carcinoma (ccRCC) samples and clinical pathological variables and overall survival was investigated. We evaluated the prognostic value of miR-663a expression in ccRCC by experimental results.

RESULTS

The results showed that the expression of miR-663a was up-regulated in RCC cells and tissues and miR-663a was associated with proliferation, migration, invasion, and apoptosis of RCC. Cox proportional hazard regression analysis showed that a high expression of miR-663a patients had a significantly shorter overall survival in univariate and multivariate analysis. Kaplan-Meier survival curves showed that a high expression of miR-663a patients had a significantly shorter overall survival.

CONCLUSIONS

These results indicate that miR-663a can be used as an independent marker for the poor prognosis of ccRCC, and may also play an important role as a tumor oncogene in the occurrence and development of RCC.

Downregulation of MicroRNA-449 Promotes Migration and Invasion of Breast Cancer Cells by Targeting Tumor Protein D52 (TPD52)

Our study aimed to investigate whether microRNA-449 (miR-449) plays a key role in regulating the migration and invasion of breast cancer cells via targeting tumor protein D52 (TPD52). The results of the qRT-PCR and Western blotting showed that, in comparison with normal breast tissues and cells, miR-449 was significantly downregulated in breast cancer tissues and cells, while TPD52 was markedly upregulated. After transfection with an miR-449 inhibitor, suppression of miR-449 significantly promoted cell migration and invasion. Also, when miR-449 was overexpressed by transfection with miR-449 mimics, E-cadherin expression significantly increased, and the expression of N-cadherin and vimentin were markedly decreased, whereas the opposite effects were obtained when miR-449 was suppressed by transfection with an miR-449 inhibitor. TPD52 was also confirmed as the direct target of miR-449 via luciferase reporter analysis. Knockdown of TPD52 significantly alleviated the effects of miR-449 overexpression on cell migration and invasion, as well as the expression of E-cadherin, N-cadherin, and vimentin. Our results indicate that downregulation of miR-449 may promote the migration and invasion of breast cancer cells by targeting TPD52. miR-449 may serve as a potential target in the therapy of breast cancer.