The PDGF-D/miR-106a/Twist1 pathway orchestrates epithelial-mesenchymal transition in gemcitabine resistance hepatoma cells. Oncotarget. 2015;6:7000-7010. [PMID: 25760076 DOI: 10.18632/oncotarget.3193]

The interplay between microRNAs and Twist1 transcription factor: a systematic review

Twist1 (also known as Twist) is a transcription factor that belongs to the family of basic helix-loop-helix (bHLH) proteins. It functions as a negative regulator of epithelial gene expression and a positive regulator of mesenchymal gene expression, thereby leading to induction of the epithelial mesenchymal transition (EMT), a process in which epithelial cells acquire the motile and migratory characteristics of mesenchymal cells. In addition to regulating the expression of protein-coding genes, Twist1 regulates the expression of microRNAs (miRNAs), adding a regulatory layer to EMT induction. Interestingly, the mRNA of Twist1 represents a downstream target of miRNAs, indicating an intricate network between miRNAs and Twist1. This network was shown to play multiple roles in cancer cell migration, invasion, and metastasis. The network can induce angiogenesis, protect cells from oncogene-induced apoptosis and senescence, enhance cancer cell resistance to conventional therapies, and increase cancer stem cell (CSC) populations. Recently, miRNAs have attracted considerable attention as potential promising tools in cancer therapies. Thus, this systematic review was conducted to clarify the reciprocal link between Twist1 and miRNAs in order to provide potential candidate miRNAs for diagnostic and therapeutic approaches in cancer treatment.

MiR-130a-3p regulates cell migration and invasion via inhibition of Smad4 in gemcitabine resistant hepatoma cells

Background

Emerging evidence demonstrates that microRNAs (miRNAs) play an important role in regulation of cell growth, invasion and metastasis through inhibiting the expression of their targets. It has been reported that miR-130a-3p controls cell growth, migration and invasion in a variety of cancer cells. However, it is unclear whether miR-130a-3p regulates epithelial-mesenchymal transition (EMT) in drug resistant cancer cells. Therefore, in the current study, we explore the role and molecular mechanisms of miR-130a-3p in gemcitabine resistant (GR) hepatocellular carcinoma (HCC) cells.

Methods

The real-time RT-PCR was used to measure the miR-130a-3p expression in GR HCC cells compared with their parental cells. The wound healing assay was conducted to determine the cell migratory activity in GR HCC cells treated with miR-130a-3p mimics. The migration and invasion assays were also performed to explore the role of miR-130a-3p in GR HCC cells. Western blotting analysis was used to measure the expression of Smad4, E-cadherin, Vimentin, and MMP-2 in GR HCC cells after depletion of Smad4. The luciferase assay was conducted to validate whether Smad4 is a target of miR-130a-3p. The student t-test was used to analyze our data.

Results

We found the down-regulation of miR-130a-3p in GR HCC cells. Moreover, we validate the Smad4 as a potential target of miR-130a-3p. Furthermore, overexpression of miR-130a-3p suppressed Smad4 expression, whereas inhibition of miR-130a-3p increased Smad4 expression. Consistently, overexpression of miR-130a-3p or down-regulation of Smad4 suppressed the cell detachment, attachment, migration, and invasion in GR HCC cells.

Conclusions

Our findings provide a molecular insight on understanding drug resistance in HCC cells. Therefore, activation of miR-130a-3p or inactivation of Smad4 could be a novel approach for the treatment of HCC.