Membrane Androgen Receptor Down-Regulates c-Src-Activity and Beta-Catenin Transcription and Triggers GSK-3beta-Phosphorylation in Colon Tumor Cells

Objective: This study aims to explore the effects of microRNA-27a (miR-27a) on the proliferation and invasiveness of colon cancer cells through the Secreted Frizzled-related protein 1 (SFRP1) and the Wnt/β-catenin signaling pathway. Methods: Colon cancer tissues and adjacent normal tissues from 125 colon cancer patients, together with the HCEpic, HCT-116, HT-29, SW480 and SW620 cell lines, were prepared for this study. The transfected HCT-116 cells were divided into the miR-27a mimics, miR-27a-NC, anti-miR-27a, blank, Lv-SFRP1, Lv-NC, and miR-27a mimics + Lv-SFRP1 groups. RT-qPCR was performed to detect the expressions of miR-27a and SFRP1 mRNA. A dual-luciferase reporter assay was conducted to examine the effect of miR-27a on SFRP1. Western blotting was used to measure the expressions of the SFRP1, β-catenin, GSK-3β, p-β-catenin, p-GSK-3β, c-Myc and cyclin D1 proteins. MTT, soft agar clone formation and Transwell chamber assays were performed to detect cell proliferation and invasion. Results: Compared with normal tissues and cells, colon cancer tissues and cells demonstrated significantly higher expression of miR-27a, but lower expressions of SFRP1 mRNA and protein. MiR-27a negatively regulated the expression of SFRP1 mRNA. SFRP1 was also found to be a target gene of miR-27a. In the miR-27a mimic group, the proliferation and invasiveness of colon cancer cells were significantly increased, while the expressions of GSK-3 β and p-β-catenin were remarkably down-regulated; in contrast, the expressions of p-GSK-3β, -catenin, c-Myc and cyclin D1 were up-regulated. While the proliferation and invasiveness of colon cancer cells in the anti-miR-27a and Lv-SFRP1 groups were decreased, the expressions of GSK-3β and p-β-catenin were elevated, and the expressions of p-GSK-3β, β-catenin, c-Myc and cyclin D1 were decreased. Conclusion: These findings indicated that miR-27a could promote the proliferation and invasiveness of colon cancer cells by targeting SFRP1 through the Wnt/β-catenin signaling pathway.

Section: Discussionmentioning

confidence: 99%

MicroRNA-27a Promotes the Proliferation and Invasiveness of Colon Cancer Cells by Targeting SFRP1 through the Wnt/β-Catenin Signaling Pathway

Yao

Long

et al. 2017

“…Although it was supposed that Na + /K + ATPase and mAR are not identical [10], based on the similarity of the downstream signaling events triggered by istaroxime [9, 10] and mAR activation [summarized in [55] and [23]] it was assumed that Na + /K + ATPase and mAR may be functionally interlinked [10]. The results of the present study further support this notion.…”

Section: Discussionsupporting

confidence: 73%

Istaroxime Inhibits Motility and Down-Regulates Orai1 Expression, SOCE and FAK Phosphorylation in Prostate Cancer Cells

Stagno

Zacharopoulou

Bochem

et al. 2017

Self Cite

Background/Aims: Istaroxime is a validated inotropic Na⁺/K⁺ ATPase inhibitor currently in development for the treatment of various cardiac conditions. Recent findings established that this steroidal drug exhibits potent apoptotic responses in prostate tumors in vitro and in vivo, by affecting key signaling orchestrating proliferation and apoptosis, such as c-Myc and caspase 3, Rho GTPases and actin cytoskeleton dynamics. In the present study we examined whether istaroxime is affecting cell motility and analyzed the underlying mechanism in prostate tumor cells. Methods: Migration was assessed by transwell and wound healing assays, Orai1 and Stim1 abundance by RT-PCR and confocal immunofluorescence microscopy, Fura-2 fluorescence was utilized to determine intracellular Ca²⁺ and Western blotting for FAK/pFAK measurements. Results: We observed strong inhibition of cell migration in istaroxime treated DU-145 prostate cancer cells. Istaroxime further decreased Orai1 and Stim1 transcript levels and downregulated Orai1 protein expression. Moreover, SOCE was significantly decreased upon istaroxime treatment. Furthermore, istaroxime strikingly diminished phosphorylated FAK levels. Interestingly, the efficacy of istaroxime on the inhibition of DU-145 cell migration was further enhanced by blocking Orai1 with 2-APB and FAK with the specific inhibitor PF-00562271. These results provide strong evidence that istaroxime prevents cell migration and motility of DU-145 prostate tumor cells, an effect at least partially attributed to Orai1 downregulation and FAK de-activation. Conclusion: Collectively our results indicate that this enzyme inhibitor, besides its pro-apoptotic action, affects motility of cancer cells, supporting its potential role as a strong candidate for further clinical cancer drug development.

“…The expression of β-catenin releases cell cycle arrest mediated by exogenous E-cadherin, and regulates the cell cycle at the G2/M phase in normal and transformed epidermal keratinocytes and Sodium iodate (NaIO3) increased apoptosis, inhibited mitosis, proliferation through inhibition of the Wnt/β-catenin and noggin pathways [24,25,26,27]. But upregulated the expression of β-catenin can induced apoptosis in vascular smooth muscle cells (VSMCs) and colon tumor cells [28,29]. Our results show that mRNA and protein levels of β-catenin are downregulated following Wnt5a knockdown in HaCaT keratinocytes.…”

Section: Discussionmentioning

confidence: 99%

Wnt/β-Catenin and Wnt5a/Ca2+ Pathways Regulate Proliferation and Apoptosis of Keratinocytes in Psoriasis Lesions

Zhang

et al. 2015

Background/Aims: Wnt5a is overexpressed in psoriasis lesions, however the mechanism by which Wnt5a is involved in the pathogenesis of psoriasis is not clear. To address this, the expression of Wnt5a in psoriatic lesions and its effect on keratinocyte cell proliferation and apoptosis was examined in vitro. Methods: The expression levels of WNT5A, and genes encoding its receptors frizzled2 (FZD2) and frizzled5 (FZD5) were examined in samples obtained from individuals with psoriasis and healthy controls. Knockdown of Wnt5a with short interfering (si)RNAs was performed in cultured HaCaT keratinocytes and normal human keratinocytes (NHK), and the expression of Wnt5a, protein kinase C (PKC), and β-catenin were determined, and cell cycle activity, proliferation and apoptosis were assessed. Results: The expression of WNT5A, FZD2 and FZD5 mRNA and protein were increased in psoriatic lesions. Wnt5a knockdown suppressed proliferation and induced apoptosis in HaCaT and NHK cells. Additionally, expression of PCNA, MKI67, CCND1, BCL2, CTNNB1, and genes encoding PKC and survivin were downregulated, whereas CASP3 was upregulated. The mRNA levels of the Wnt pathway inhibitors DKK1 and SFRP1 were upregulated, Western blotting analyses demonstrated reduction in β-catenin and PKC protein levels. Conclusion: Knockdown of Wnt5a suppresses the proliferation of keratinocytes and induces apoptosis by inhibiting the Wnt/β-catenin or Wnt5a/Ca²⁺ pathways.