Lei Liu1, Yan-Chun Tian2, Gang Mao3, Yun-Gui Zhang1, Li Han4. 1. Department Of Gastroenterology, The Fourth People's Hospital of Jinan, Jinan, Shandong, PR China. 2. Sterrilization And Suplly Center, The Fourth People's Hospital of Jinan, Jinan, Shandong, PR China. 3. Emergency Department, The Fourth People's Hospital of Jinan, Shandong, PR China. 4. Quality Control/Management Office, The Fourth People's Hospital of Jinan, Jinan, Shandong, PR China. Electronic address: hanli12321@163.com.
Abstract
BACKGROUND: Gastric cancer (GC) is a common malignancy around the world. Irregular expression of microRNAs (miRNAs) contributes to the progression of malignancies. Our study illustrated that miR-675 facilitates GC proliferation and invasion via targeting paired-like homeodomain transcription factor 1 (PITX1) and promoting epithelial-mesenchymal transition (EMT) as well as Wnt/β-catenin signaling pathway. METHODS: We collected the RNA-seq data of GC and normal stomach tissues from TCGA database to analyze the expression of miR-675 and PITX1. Kaplan-Meier plotter on line tool was used to analyze the association between miR-675 or PITX1 expression and the overall survival of GC patients. The biological function of miR-675 in GC cells was evaluated via altering its expression using miR-675 agomiR or antamiR. Dual-luciferase reporter assay was applied for verifying whether miR-675 could direct bind to 3'UTR of PITX1. Rescue assays were applied for characterizing the effects of miR-675/PITX1 axis on GC growth and invasion. Western blot was performed to evaluate the protein expression levels of PITX1, EMT-related and Wnt signaling-related proteins. RESULTS: Our results showed that miR-675 is up-regulated and predictive of worse prognosis in GC patients. Overexpression of miR-675 in AGS cells notably promoted cell proliferation, migration and invasion, whilst down-regulation of miR-675 in SGC-7901 cells gained the opposite results. PITX1 is down-regulated in GC and identified as a direct target of miR-675. Overexpression of PITX1 in AGS cells reverses cell viability and invasion that enhanced by miR-675 up-regulation. Conversely, depletion of PITX1 in SGC-7901 cells rescues cell viability and invasion that inhibited by miR-675 down-regulation. Western bolt results revealed that miR-675 positively regulated EMT and Wnt/β-catenin signaling pathway in GC cells via targeting PITX1. CONCLUSIONS: Our study emphasized the functional mechanism of miR-675 in GC and intimated that miR-675/PITX1 axis possibly affects proliferative and invasive properties of GC cells via regulating EMT and Wnt/β-catenin signaling pathway. Furthermore, miR-675 and PITX1 may be served as early diagnostic markers as well as therapeutic targets for GC.
BACKGROUND:Gastric cancer (GC) is a common malignancy around the world. Irregular expression of microRNAs (miRNAs) contributes to the progression of malignancies. Our study illustrated that miR-675 facilitates GC proliferation and invasion via targeting paired-like homeodomain transcription factor 1 (PITX1) and promoting epithelial-mesenchymal transition (EMT) as well as Wnt/β-catenin signaling pathway. METHODS: We collected the RNA-seq data of GC and normal stomach tissues from TCGA database to analyze the expression of miR-675 and PITX1. Kaplan-Meier plotter on line tool was used to analyze the association between miR-675 or PITX1 expression and the overall survival of GC patients. The biological function of miR-675 in GC cells was evaluated via altering its expression using miR-675 agomiR or antamiR. Dual-luciferase reporter assay was applied for verifying whether miR-675 could direct bind to 3'UTR of PITX1. Rescue assays were applied for characterizing the effects of miR-675/PITX1 axis on GC growth and invasion. Western blot was performed to evaluate the protein expression levels of PITX1, EMT-related and Wnt signaling-related proteins. RESULTS: Our results showed that miR-675 is up-regulated and predictive of worse prognosis in GC patients. Overexpression of miR-675 in AGS cells notably promoted cell proliferation, migration and invasion, whilst down-regulation of miR-675 in SGC-7901 cells gained the opposite results. PITX1 is down-regulated in GC and identified as a direct target of miR-675. Overexpression of PITX1 in AGS cells reverses cell viability and invasion that enhanced by miR-675 up-regulation. Conversely, depletion of PITX1 in SGC-7901 cells rescues cell viability and invasion that inhibited by miR-675 down-regulation. Western bolt results revealed that miR-675 positively regulated EMT and Wnt/β-catenin signaling pathway in GC cells via targeting PITX1. CONCLUSIONS: Our study emphasized the functional mechanism of miR-675 in GC and intimated that miR-675/PITX1 axis possibly affects proliferative and invasive properties of GC cells via regulating EMT and Wnt/β-catenin signaling pathway. Furthermore, miR-675 and PITX1 may be served as early diagnostic markers as well as therapeutic targets for GC.