Silencing of lncRNA EZR-AS1 inhibits proliferation, invasion, and migration of colorectal cancer cells through blocking transforming growth factor β signaling.

Long non-coding RNA (lncRNA) plays a key regulatory role in the pathogenesis of colorectal cancer (CRC). In the present study, the specific regulatory role of lncRNA ezrin antisense RNA 1 (EZR-AS1) on CRC was investigated. The expression of lncRNA EZR-AS1 was significantly up-regulated in CRC cell lines (HCT8, HCT116, HT29, and SW620 cells), which was significantly different from that of normal human fetal colonic mucosa cells (FHC cells) (P<0.01). HCT116 and HT29 cells were then transfected with EZR-AS1 shRNA (sh-EZR-AS1) to silence lncRNA EZR-AS1 (P<0.01). When compared with the Control, after transfection of SH-EZR-AS1, E-cadherin was up-regulated, Vimentin was down-regulated, the apoptosis rate was increased, the cell viability, wound healing rate, and the number of invasive cells were decreased in HCT116 and HT29 cells (P<0.05). Silencing of lncRNA EZR-AS also significantly reduced the tumor volume and weight in mice injected with sh-EZR-AS1-transfected HCT116 and HT29 cells (P<0.05). The regulatory relationship between lncRNA EZR-AS1 and transforming growth factor β (TGF-β) signaling was further identified in CRC cells. Silencing of lncRNA EZR-AS1 significantly down-regulated TGF-β, Smad2, and α-SMA expression in HCT116 and HT29 cells at the protein level (P<0.05). The intervention of SB431542 (a TGF-β receptor blocker) and silencing of Smad2 both significantly down-regulated lncRNA EZR-AS1 expression in HCT116 and HT29 cells (P<0.01). In conclusion, silencing of lncRNA EZR-AS1 inhibited the proliferation, invasion, migration, and epithelial-mesenchymal transition, and promoted the apoptosis of CRC cells through blocking TGF-β signaling.

Liu Z ，Wang N ，Wang F ，Zhang S ，Ding J ... -  《-》

Non-coding RNA MFI2-AS1 promotes colorectal cancer cell proliferation, migration and invasion through miR-574-5p/MYCBP axis.

Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) play essential roles in the tumour progression. LncRNAs mostly act as competing endogenous RNAs (ceRNAs) by sponging miRNAs. This study aimed to study the association of a novel lncRNA MFI2-AS1 with miR-574-5p/MYCBP axis in the development of colorectal cancer (CRC). Ninety-four CRC tissues and paired adjacent non-tumour tissues were included in our study. The relative expression level of MFI2-AS1 was detected, and its relationship with clinico-pathological factors was analysed. Then, the CRC cells lines (LoVo and RKO) were transfected with MFI2-AS1 siRNA, miR-574-5p mimics and inhibitors. Cell proliferation, migration, invasion, cell cycle distribution and DNA damage in response to different transfection conditions were examined. Dual-luciferase reporter assay was performed to identify the target interactions between MFI2-AS1 and miR-574-5p, miR-574-5p and MYCBP. LncRNA MFI2-AS1 and MYCBP were up-regulated in CRC tissues when compared with adjacent non-tumour tissues. The expression levels of MFI2-AS1 were significantly associated with tumour histological grade, lymph and distant metastasis, TNM stage and vascular invasion. Both MFI2-AS1 siRNA and miR-574-5p mimics inhibited proliferation, migration and invasion in LoVo and RKO cells. The transfection of miR-574-5p inhibitor showed MFI2-AS1 siRNA-induced changes in CRC cells. Dual-luciferase reporter assay revealed target interactions between MFI2-AS1 and miR-574-5p, miR-574-5p and MYCBP. These findings suggested that lncRNA MFI2-AS1 and MYCBP have promoting effects in CRC tissues. LncRNA MFI2-AS1 promoted CRC cell proliferation, migration and invasion through activating MYCBP and by sponging miR-574-5p.

Li C ，Tan F ，Pei Q ，Zhou Z ，Zhou Y ，Zhang L ，Wang D ，Pei H ... -  《-》

Long noncoding RNA HNF1A-AS1 indicates a poor prognosis of colorectal cancer and promotes carcinogenesis via activation of the Wnt/β-catenin signaling pathway.

Long non-coding RNAs (lncRNAs) have been identified to play critical roles in tumorigenesis. LncRNA HNF1A-AS1 has been suggested to act as an oncogene and serves as a novel prognostic biomarker for various cancer. However, the biological role and clinical significance of lncRNA HNF1A-AS1 in colorectal cancer (CRC) have yet to be fully elusive. Therefore, the present study was designed to determine the expression of lncRNA HNF1A-AS1 in patients with CRC, the role of lncRNA HNF1A-AS1 in CRC cells, as well as the underlying regulatory mechanisms. Our results indicated that the expression of lncRNA HNF1A-AS1 was significantly upregulated in both CRC tumor tissues and CRC cell lines in comparison with adjacent non-tumor tissues and the human normal colonic epithelial cell line (HcoEpiC). The Kaplan-Meier survival analysis further suggested that high expression of lncRNA HNF1A-AS1 might be an independent prognostic factor for disease-free survival (DFS) and overall survival (OS) in patients with CRC. Moreover, the area under the receiver operating characteristic (ROC) curve for HNF1A-AS1 was up to 0.8714, implying that HNF1A-AS1 had diagnostic significance as it could discriminate tumor tissues from nontumorous tissues. In addition, silencing of lncRNA HNF1A-AS1 abrogated the proliferation of CRC cells by MTS assay and clonogenic assay, arrested cell cycle at G0/G1 stage and reduced the migration and invasion in CRC cells. Finally, we found that decreased expression of lncRNA HNF1A-AS1 suppressed the Wnt/β-catenin signaling pathway activity by downregulating the expression of β-catenin,cyclinD1, and c-myc. In conclusion, these findings provide evidence that lncRNA HNF1A-AS1 may be considered as a new prognostic biomarker and therapeutic target in patients with CRC.

Zhang X ，Xiong Y ，Tang F ，Bian Y ，Chen Y ，Zhang F ... -  《-》

Long non-coding RNA TP73-AS1 sponges miR-194 to promote colorectal cancer cell proliferation, migration and invasion via up-regulating TGFα.

Cai Y ，Yan P ，Zhang G ，Yang W ，Wang H ，Cheng X ... -  《-》

Long non-coding RNA FOXP4-AS1 is an unfavourable prognostic factor and regulates proliferation and apoptosis in colorectal cancer.

Despite improvements in diagnosis and treatment, colorectal cancer (CRC) remains the third most common malignancy, and fourth-leading cause of cancer-related death worldwide, and has a particularly high incidence in Western countries. Recent studies have suggested that long non-coding RNAs (lncRNAs) compose a novel class of regulators of cancer biological processes, such as proliferation, apoptosis and metastasis. Here, we report that lncRNA FOXP4-AS1 acts as a functional oncogene in CRC pathogenesis. Moreover, we have attempted to investigate the effects of FOXP4-AS1 on tumour progression, both in vitro and in vivo. In this study, bioinformatic analyses and qPCR were performed to investigate FOXP4-AS1 expression in CRC tissue samples and CRC cell lines. We inhibited FOXP4-AS1 expression via FOXP4-AS1-specific siRNA transfection. Cell proliferation was assessed using cell viability and colony formation assays, as well as by flow cytometry and ethynyl deoxyuridine (Edu) analyses. Apoptosis was assessed using flow cytometry. Animal tumour xenografts were generated, and immunohistochemistry (IHC) was performed to evaluate effects of FOXP4-AS1 on CRC tumour growth in vivo. We found that FOXP4-AS1 was up-regulated in CRC tissues and cell lines and that its overexpression positively correlated with advanced pathological stages and larger tumour size. Additionally, we found that FOXP4-AS1 knockdown inhibited cell proliferation and induced apoptosis. Furthermore, FOXP4-AS1 knockdown induced marked increase in number of cells in G0/G1 phase and reduction in number of cells in S phase, in DLD-1, HT-29 and HCT116 cell lines. Consistent with these findings, FOXP4-AS1 silencing inhibited tumour growth in vivo. These findings suggest that FOXP4-AS1 plays a crucial role in CRC progression and may be a new biomarker in patients with CRC.

Li J ，Lian Y ，Yan C ，Cai Z ，Ding J ，Ma Z ，Peng P ，Wang K ... -  《-》