Effect of arsenic trioxide on epithelial-mesenchymal transition via induction of SH2?containing protein tyrosine phosphatase 1.

2017 ◽  
Vol 35 (4_suppl) ◽  
pp. 76-76
Author(s):  
Jong-Jae Park ◽  
Moon Kyung Joo ◽  
Hyo Soon Yoo ◽  
Beom Jae Lee ◽  
Taehyun Kim ◽  
...  

76 Background: Arsenic trioxide (ATO) is known to inhibit epithelial-mesenchymal transition (EMT) in hepatolocellular carcinoma and breast cancer cells, however, little has been reported in gastric cancer cells. In this study, we aimed to investigate the mechanism of ATO to inhibit signal transducer and activator of transcription 3 (STAT3) activity and EMT in gastric cancer cells. Methods: We performed wound closure assay and Matrigel invasion assay for functional studies of EMT, and western blot for measurement of protein markers using AGS gastric cancer cells. Results: Compared with control, 5 and 10 μM of ATO significantly inhibited cellular migration and inhibition in a dose-dependent manner. Furthermore, ATO significantly downregulated snail expression, a mesenchymal marker, and upregulated E-cadherin expression, an epithelial marker. We could observe that ATO induced SH2-containing protein tyrosine phosphatase 1 (SHP1), a non-receptor type protein tyrosine phosphatase, and subsequently downregulated phospho-STAT3 in a dose-dependent manner. To validate the molecular link between ATO and SHP1 to inhibit EMT in gastric cancer cell, we pre-treated 50 μM of pervanadate, a phosphatase inhibitor, before treatment of 10 μM ATO, and this significantly abolished anti-invasive effect by ATO in AGS cells. In xenograft tumor model, intraperitoneal injection of ATO significantly reduced the tumor volume and upregulated SHP-1 expression by immunohistochemistry stain compared with vehicle, which were reversed by ATO with pervanadate injection. Conclusions: Our findings suggest that ATO may show anti-EMT effects via induction of SHP1 and inhibition of STAT3 activity in gastric cancer cells.

2009 ◽  
Vol 20 (24) ◽  
pp. 5127-5137 ◽  
Author(s):  
Kai-Wen Hsu ◽  
Rong-Hong Hsieh ◽  
Chew-Wun Wu ◽  
Chin-Wen Chi ◽  
Yan-Hwa Wu Lee ◽  
...  

The c-Myc promoter binding protein 1 (MBP-1) is a transcriptional suppressor of c-myc expression and involved in control of tumorigenesis. Gastric cancer is one of the most frequent neoplasms and lethal malignancies worldwide. So far, the regulatory mechanism of its aggressiveness has not been clearly characterized. Here we studied roles of MBP-1 in gastric cancer progression. We found that cell proliferation was inhibited by MBP-1 overexpression in human stomach adenocarcinoma SC-M1 cells. Colony formation, migration, and invasion abilities of SC-M1 cells were suppressed by MBP-1 overexpression but promoted by MBP-1 knockdown. Furthermore, the xenografted tumor growth of SC-M1 cells was suppressed by MBP-1 overexpression. Metastasis in lungs of mice was inhibited by MBP-1 after tail vein injection with SC-M1 cells. MBP-1 also suppressed epithelial-mesenchymal transition in SC-M1 cells. Additionally, MBP-1 bound on cyclooxygenase 2 (COX-2) promoter and downregulated COX-2 expression. The MBP-1-suppressed tumor progression in SC-M1 cells were through inhibition of COX-2 expression. MBP-1 also exerted a suppressive effect on tumor progression of other gastric cancer cells such as AGS and NUGC-3 cells. Taken together, these results suggest that MBP-1–suppressed COX-2 expression plays an important role in the inhibition of growth and progression of gastric cancer.


2020 ◽  
Author(s):  
Hanshu Ji ◽  
Xiaoyu Zhang

Abstract Purpose: lncRNA NEAT1 has been reported as a tumor-promoting gene in a variety of tumors, but few studies have explored its role and mechanism in gastric cancer. In the face of increasing incidence of gastric cancer, how to improve the diagnostic accuracy and therapeutic effect of gastric cancer is a major clinical problem. Therefore, we studied the effect and mechanism of lncRNA NEAT1 on the proliferation, invasion and epithelial-mesenchymal transition of gastric cancer cells. To inquiry into the effect of lncRNA NEAT1 on the proliferation, invasion and epithelial-mesenchymal transition (EMT) of gastric cancer (GC) cells by regulating miR-129-5p/PBX3 axis. Methods: Totally 63 GC diagnosed and treated in our hospital were selected as the study subjects, whose paired GC tissues and pericarcinomatous tissues were collected as the study specimens after obtaining their consent. QRT-PCR was employed to detect the NEAT1 expression in tissues and cells to analyze the relationship between NEAT1 and clinicopathological data of GC patients. In addition, stable and transient overexpression and inhibition vectors were established and transfected into GC cells HCG-27 and MKN-45. CCK-8, traswell, and flow cytometry were employed to evaluate the proliferation, invasion, and apoptosis of transfected cells. The correlation of miR-129-5p between PBX3 and NEAT1 was assessed using dual luciferase reporter assay, while that between NEAT1 and miR-129-5p was assessed by RNA-binding protein immunoprecipitation (RIP) . Western blot was applied for the detection of apoptosis and EMT related proteins.Results: NEAT1 was overexpressed in GC patients and had a high diagnostic value. The expression of NEAT1 was related to the pathological stage, differentiation degree, tumor size and lymph node metastasis of patients with GC. Down-regulated NEAT1 brought decreased cell proliferation, invasion and EMT, and increased apoptosis. According to dual luciferase reporter assay, NEAT1 could target miR-129-5p, while in turn miR-129-5p could target PBX3. Functional analysis exhibited that miR-129-5p overexpression inhibited PBX3 in GC cells, affecting cell proliferation, invasion, EMT and apoptosis, and rescue experiments demonstrated that these effects were eliminated by up-regulating NEAT1 expression.Conclusion: Inhibition of NEAT1 could mediate miR-129-5p/PBX3 axis to promote apoptosis of GC cells, and reduce cell proliferation, invasion and EMT.


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