Upregulation of microRNA-155 promotes the migration and invasion of colorectal cancer cells through the regulation of claudin-1 expression

Abstract

Human microRNA-155 (miR-155) has been demonstrated to regulate a variety of cellular functions, including epithelial-to-mesenchymal transition (EMT) by targeting multiple messenger RNAs (mRNAs). However, its role in colorectal cancer (CRC) remains unelucidated. Therefore, the aim of the present study was to investigate the effects of miR-155 on CRC cells. The expression level of miR-155 was quantified by quantitative real-time reverse transcriptase-PCR (qRT-PCR) in primary CRC tissues and normal adjacent mucosa. MTT, migration and invasion assays were used to examine the proliferation, migration and invasion of SW480 cells transfected with miR‑155. The expression of miR-155 was significantly upregulated in the CRC tissues and the high expression of miR-155 correlated with an advanced clinical stage, lymph node and distant metastases. The ectopic expression of miR-155 enhanced the migration and invasive ability of the SW480 cells and altered their morphological appearance; however, cell proliferation was not affected. E-cadherin expression levels decreased, while ZEB1 expression levels increased in the SW480 cells overexpressing miR-155. Furthermore, the overexpression of miR-155 upregulated claudin-1 expression. Thus, our data suggest that miR-155 plays an important role in promoting CRC cell migration and invasion, at least in part through the regulation of claudin-1 expression and controlling metastasis in CRC.

MicroRNA-155 enhances the activation of Wnt/β-catenin signaling in colorectal carcinoma by suppressing HMG-box transcription factor 1

“…The results of the present study supported these findings in CRC specimens. The role of miR-155 in CRC has been reported to be associated with enhanced invasion and metastasis (8). The present study also demonstrated that miR-155 promoted the proliferation of CRC cells, suggesting that targeting miR-155 may be an effective therapeutic strategy to the control the growth of CRC.…”

“…miR-155 is an oncogenic miRNA in several types of cancer, which has been demonstrated to promote the initiation and progression of malignant tumors (5). In addition, the diagnostic and prognostic value of miR-155 has been verified in previous studies (6)(7)(8).…”

“…The overall survival and disease-free survival rates of patients with high expression levels of miR-155 are significantly reduced, compared with those of patients with low expression levels of miR-155 (7). Zhang et al (8) reported that miR-155 promotes the migration and invasion of CRC cells, possibly by regulating the expression of claudin-1. In addition to its role in existing CRC tumors, miR-155 may also contribute to the initiation of CRC.…”

Inhibition of MicroRNA‐155 Supports Endothelial Tight Junction Integrity Following Oxygen‐Glucose Deprivation

“…CLDN1, one of the major components of TJs, is among the direct targets of miR‐155 42, 43. While CLDN5 is highly expressed in the brain endothelium, CLDN1 expression in cerebral capillaries is low and was only confirmed to be present in human, rat, and sheep BBB 3, 30, 31.…”

microRNA Expression Profile in Patients with Stage II Colorectal Cancer: A Turkish Referral Center Study

“…On the other side, in Zhang et al study it has been shown that miR-155 levels are upregulated in CRC tissues. They also suggested that upregulation of microRNA-155 promotes the migration and invasion of colorectal cancer cells (Zhang et al, 2013). From the other point of view, it has been demonstrated that miR-200c levels are significantly upregulated in CRC tissues (Della Vittoria Scarpati et al, 2014).…”