Dysregulated noncoding RNAs have been observed in diverse cancers. MIR458K is frequently amplified in esophageal squamous cell carcinoma (ESCC). However， the expression， clinical significances， and action mechanisms of miR-548k in ESCC are still unclear. In this study， we found that miR-548k is significantly up-regulated in ESCC tissues and cell lines. Up-regulated miR-548k expression is significantly correlated with advanced invasion depth， lymph node metastasis， advanced TNM stage， and poor overall survival. Gain-of- and loss-of-function assays demonstrated that miR-548k promotes the proliferation and migration of ESCC cells in vitro and tumor growth in vivo. Mechanistically， we found that miR... More
Dysregulated noncoding RNAs have been observed in diverse cancers. MIR458K is frequently amplified in esophageal squamous cell carcinoma (ESCC). However， the expression， clinical significances， and action mechanisms of miR-548k in ESCC are still unclear. In this study， we found that miR-548k is significantly up-regulated in ESCC tissues and cell lines. Up-regulated miR-548k expression is significantly correlated with advanced invasion depth， lymph node metastasis， advanced TNM stage， and poor overall survival. Gain-of- and loss-of-function assays demonstrated that miR-548k promotes the proliferation and migration of ESCC cells in vitro and tumor growth in vivo. Mechanistically， we found that miR-548k directly targets and represses the expression of long noncoding RNA-LET (lncRNA-LET)， and further down-regulates p53 and up-regulates NF90. In addition， we found that lncRNA-LET is down-regulated and inversely correlated with miR-548k in ESCC. Down-regulated lncRNA-LET also indicated poor overall survival of ESCC patients. Functional assays demonstrated that lncRNA-LET inhibits the proliferation and migration of ESCC cells， and the effects of miR-548k on ESCC are dependent on the negative regulation of lncRNA-LET. In summary， our data revealed the critical roles of miR-548k-lncRNA-LET regulation axis in ESCC and suggested that the miR-548k-lncRNA-LET regulation axis may be promising prognostic biomarkers and therapeutic targets for ESCC.
