Browsing by Subject "Tumorigenicity"

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    Evidence for a potential tumor suppressor role for the Na,K-ATPase B1-subunit
    (Murcia : F. Hernández, 2008) Inge, Landon J.; Rajasekaran, Sigrid A.; Yoshimoto, Koji; Mischel, Paul S.; McBride, William; Landaw, Elliot; Rajasekaran, Ayyappan K.
    The Na,K-ATPase, consisting of two essential subunits (a, ß), plays a critical role in the regulation of ion homeostasis in mammalian cells. Recent studies indicate that reduced expression of the ß1 isoform (NaK-ß1) is commonly observed in carcinoma and is associated with events involved in cancer progression. In this study, we present evidence that repletion of NaK-ß1 in Moloney sarcoma virustransformed Madin-Darby canine kidney cells (MSVMDCK), a highly tumorigenic cell line, inhibits anchorage independent growth and suppresses tumor formation in immunocompromised mice. Additionally, using an in vitro cell-cell aggregation assay, we showed that cell aggregates of NaK-ß1 subunit expressing MSVMDCK cells have reduced extracellular regulated kinase (ERK) 1/2 activity compared with parental MSV-MDCK cells. Finally, using immunohistochemistry and fully quantitative image analysis approaches, we showed that the levels of phosphorylated ERK 1/2 are inversely correlated to the NaK-ß1 levels in the tumors. These findings reveal for the first time that NaK-ß1 has a potential tumor-suppressor function in epithelial cells.
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    The suppressive effects of miR-1180-5p on the proliferation and tumorigenicity of bladder cancer cells
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2017) Ge, Qiangqiang; Wang, Chenghe; Chen, Zhong; Li, Fan; Hu, Jia; Ye, Zhangqun
    In our previous research, we have reported that a candidate microRNA (miR-1180-5p) has the capacity to induce overexpression of tumor suppressor gene p21 and inhibit the growth of human bladder cancer (BCa) cell lines in vitro. However, the exact mechanism as to how miR-1180-5p suppresses BCa cell proliferation remains unknown, and the inhibitory effect of miR-1180-5p in vivo also need to be investigated. In the present study, we found that the expression level of miR-1180-5p was lower in BCa cells than in normal human urothelial cells. Furthermore, we found that overexpression of p21, activated by miR-1180-5p, interfered with cell cycle progress by inhibiting the cell cycle related proteins (CDK4, CDK6, Cyclin D1 and Cyclin A2), and thereby suppressed BCa cell proliferation. In addition, miR-1180-5p also suppressed the tumor growth in vivo significantly. Taken together, our study provides evidence that up-regulation of p21 is mainly responsible for the suppressive effect of miR1180-5p on BCa cells and miR-1180-5p can significantly inhibit tumorigenicity in vivo.