A Master microRNA miR-508-3p Modulates the Mesenchymal Subtype of Colorectal Cancer by Targeting ZEB1/BMI1/SALL4 Network

Abstract

ObjectivesThe mesenchymal subtype colorectal cancer (CRC) is related to invasive and metastatic disease with poor prognosis in CRC. However, the specific molecular alterations and the driving molecular events behind the mesenchymal subtype of CRC have not been investigated.MethodsmiRNA-mRNA expression profiling studies were performed in The Cancer Genome Atlas (TCGA) CRC samples. Expression and functional analysis of the six key miRNA signatures was investigated in CRC cell lines/tissues and cells were analysed for invasion and migration both in vivo and in vitro. The prognostic significance of miR-508-3p was analysed by univariate and multivariate survival analyses. Expression of miRNA-508-3p target genes and EMT markers in CRC cell lines and tissue specimens was validated.ResultsIntegrated analyses revealed a miRNA-regulatory network that was associated with the mesenchymal subtype in 200 CRC cases from TCGA database. Six key miRNA, including miR-508, miR-506, miR-514 and miR-205 were predicted to regulate 275 mesenchymal-related genes in this network. Of the six miRNAs, integrated analysis and functional assay highlight a crucial role for miR-508 in CRC Epithelial-mesenchymal transition (EMT). Follow-up functional experiments illustrate that miR-508-3p augmented CDH1 expression, inhibited cell migration, invasion, and prevented TGF β-induced EMT by targeting ZEB1, SALL4 and BMI1 both in vitro and in vivo. MiR508-3p expression was correlated with decreased ZEB1, VIM and N-cadherin, elevated CDH1 and beneficial prognosis in CRC patients. MiR-508-3p may be regulated by methylation in CRC. The associations between miR-508-3p, target genes, EMT markers and the prognosis value of miR-508-3p were validated in paired normal and cancerous colorectal tissues.ConclusionsMiR-508-3p may be a master microRNA of the mesenchymal subtype of CRC and a promising target to prevent and/or treat CRC invasion and metastasis. ObjectivesThe mesenchymal subtype colorectal cancer (CRC) is related to invasive and metastatic disease with poor prognosis in CRC. However, the specific molecular alterations and the driving molecular events behind the mesenchymal subtype of CRC have not been investigated. The mesenchymal subtype colorectal cancer (CRC) is related to invasive and metastatic disease with poor prognosis in CRC. However, the specific molecular alterations and the driving molecular events behind the mesenchymal subtype of CRC have not been investigated. MethodsmiRNA-mRNA expression profiling studies were performed in The Cancer Genome Atlas (TCGA) CRC samples. Expression and functional analysis of the six key miRNA signatures was investigated in CRC cell lines/tissues and cells were analysed for invasion and migration both in vivo and in vitro. The prognostic significance of miR-508-3p was analysed by univariate and multivariate survival analyses. Expression of miRNA-508-3p target genes and EMT markers in CRC cell lines and tissue specimens was validated. miRNA-mRNA expression profiling studies were performed in The Cancer Genome Atlas (TCGA) CRC samples. Expression and functional analysis of the six key miRNA signatures was investigated in CRC cell lines/tissues and cells were analysed for invasion and migration both in vivo and in vitro. The prognostic significance of miR-508-3p was analysed by univariate and multivariate survival analyses. Expression of miRNA-508-3p target genes and EMT markers in CRC cell lines and tissue specimens was validated. ResultsIntegrated analyses revealed a miRNA-regulatory network that was associated with the mesenchymal subtype in 200 CRC cases from TCGA database. Six key miRNA, including miR-508, miR-506, miR-514 and miR-205 were predicted to regulate 275 mesenchymal-related genes in this network. Of the six miRNAs, integrated analysis and functional assay highlight a crucial role for miR-508 in CRC Epithelial-mesenchymal transition (EMT). Follow-up functional experiments illustrate that miR-508-3p augmented CDH1 expression, inhibited cell migration, invasion, and prevented TGF β-induced EMT by targeting ZEB1, SALL4 and BMI1 both in vitro and in vivo. MiR508-3p expression was correlated with decreased ZEB1, VIM and N-cadherin, elevated CDH1 and beneficial prognosis in CRC patients. MiR-508-3p may be regulated by methylation in CRC. The associations between miR-508-3p, target genes, EMT markers and the prognosis value of miR-508-3p were validated in paired normal and cancerous colorectal tissues. Integrated analyses revealed a miRNA-regulatory network that was associated with the mesenchymal subtype in 200 CRC cases from TCGA database. Six key miRNA, including miR-508, miR-506, miR-514 and miR-205 were predicted to regulate 275 mesenchymal-related genes in this network. Of the six miRNAs, integrated analysis and functional assay highlight a crucial role for miR-508 in CRC Epithelial-mesenchymal transition (EMT). Follow-up functional experiments illustrate that miR-508-3p augmented CDH1 expression, inhibited cell migration, invasion, and prevented TGF β-induced EMT by targeting ZEB1, SALL4 and BMI1 both in vitro and in vivo. MiR508-3p expression was correlated with decreased ZEB1, VIM and N-cadherin, elevated CDH1 and beneficial prognosis in CRC patients. MiR-508-3p may be regulated by methylation in CRC. The associations between miR-508-3p, target genes, EMT markers and the prognosis value of miR-508-3p were validated in paired normal and cancerous colorectal tissues. ConclusionsMiR-508-3p may be a master microRNA of the mesenchymal subtype of CRC and a promising target to prevent and/or treat CRC invasion and metastasis. MiR-508-3p may be a master microRNA of the mesenchymal subtype of CRC and a promising target to prevent and/or treat CRC invasion and metastasis.