Down-Regulation of DDR1 Induces Apoptosis and Inhibits EMT through Phosphorylation of Pyk2/MKK7 in DU-145 and Lncap-FGC Prostate Cancer Cell Lines

Background: In cancer cells, re-activation of Epithelial-Mesenchymal Transition (EMT) program through Discoidin Domain Receptor1 (DDR1) leads to metastasis. DDR1-targeted therapy with siRNA might be a promising strategy for EMT inhibition. Therefore, the aim of this study was to investigate the effect of DDR1 knockdown in the EMT, migration, and apoptosis of prostate cancer cells. For this purpose, the expression of DDR1 was down regulated by the siRNA approach in LNcap-FGC and DU-145 prostate cancer cells. Methods: Immunocytochemistry was carried out for the assessment of EMT. E-cadherin, N-cadherin, Bax, Bcl2, and the phosphorylation level of Proline-rich tyrosine kinase 2 (Pyk2) and Map Kinase Kinase 7 (MKK7) was determined using the western blot. Wound healing assay was used to evaluate cell migration. Flow cytometry was employed to determine the apoptosis rate in siRNA-transfected cancer cells. Results: Our findings showed that the stimulation of DDR1 with collagen-I caused increased phosphorylation of Pyk2 and MKK7 signaling molecules that led to the induction of EMT and migration in DU-145 and LNcap- FGC cells. In contrast, DDR1 knockdown led to significant attenuation of EMT, migration, and phosphorylation levels of Pyk2 and MKK7. Moreover, DDR1 knockdown via induction of Bax expression and suppression of Bcl-2 expression induces apoptosis. Conclusion: Collectively, our results indicate that the DDR1 targeting with siRNA may be beneficial for the inhibition of EMT and the induction of apoptosis in prostate cancer.

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Periostin Mediates TGF-β-Induced Epithelial Mesenchymal Transition in Prostate Cancer Cells

Cellular Physiology and Biochemistry ◽

10.1159/000430139 ◽

2015 ◽

Vol 36 (2) ◽

pp. 799-809 ◽

Cited By ~ 45

Author(s):

Qingfeng Hu ◽

Shijun Tong ◽

Xiaojun Zhao ◽

Weihong Ding ◽

Yuancheng Gou ◽

...

Keyword(s):

Prostate Cancer ◽

Western Blot ◽

Cancer Cells ◽

Cell Invasion ◽

Associated Factors ◽

Epithelial Mesenchymal Transition ◽

Prostate Cancer Cells ◽

Mesenchymal Transition ◽

Invasion And Migration ◽

And Migration

Background: In our previous study, we found that periostin was upregulated in prostate cancer, and its expression could be modulated by TGF-β. TGF-β could upregulate periostin expression in some cells, and both TGF-β and periostin could induce epithelial mesenchymal transition (EMT). We aimed to study the effect of periostin in the process of TGF-β-induced EMT in prostate cancer cells. Methods: We constructed a lentivirus vector containing the periostin gene and transduced it into PC3 and DU145 cells. After confirming periostin overexpression by PCR and Western blotting, we used an MTT assay to establish a growth curve to measure cell proliferation. Additionally, we performed transwell and wound healing assays to measure cell invasion and migration, respectively. Lastly, we measured the expression of EMT associated factors using Western blot analysis to test the effect of periostin on EMT in prostate cancer cells. Results: PCR and Western blot analyses confirmed that periostin was upregulated after infection with the periostin lentiviral vector. Periostin overexpression promoted increased cell proliferation, invasion, and migration as measured by MTT, transwell, and wound healing assays, respectively. Western blot analysis illustrated that periostin overexpression increased the expression of EMT associated factors, and periostin overexpression activated Akt and GSK-3β, which could be inhibited using a PI3K inhibitor. Additionally, TGF-β increased the levels of STAT3, Twist1 and periostin, while both STAT3 shRNA and Twist1 shRNA inhibited periostin expression. However, STAT3 shRNA also decreased Twist1 expression. Although reduction of STAT3, Twist1 or periostin levels with shRNA inhibited TGF-β-induced overexpression of EMT associated factors, periostin overexpression could reverse such inhibition by interfering with STAT3 and Twist1. Similarly, periostin overexpression also reversed inhibition of cell invasion induced by interference of STAT3 and Twist1. Conclusion: Our findings indicate that periostin is an important mediator of TGF-β-induced EMT and suggest that periostin is a potential therapeutic target for suppressing the metastatic progression of prostate cancer.

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