Apocynin attenuates motility and induces transition from sustained to transient EGF-dependent Akt activation in MCF-7 cells that overexpress adaptor protein Ruk/CIN85

Aim. To study a possible involvement of NADPH oxidases in the control of cell motility and Akt signaling in the human breast adenocarcinoma MCF-7 cells that stably overexpress the full-length form of adaptor protein Ruk/CIN85. Methods. Cell motility was studied by a transwell migration assay. The dynamics of EGF-induced Akt activation was investigated by Western blot analysis. Results. It has been shown that apocynin, an inhibitor of the assembly of plasma membrane NADPH oxidases, substantially attenuates the motility of Ruk/CIN85 overexpressing MCF-7 cells (subclone G10) in comparison with control cells. In addition, apocynin induced the transition from sustained to transient EGF-dependent Akt activation in G10 cells and did not influence transient Akt activation in control cells. Conclusions. The data obtained can suggest that ROS produced by NADPH oxidases are signaling components, upstream to Akt kinase, that mediate the increased migratory potential of Ruk/CIN85 overexpressing MCF-7 cells

Eleven papers on differential equations

The papers in this volume, like those in the previous one, have been selected, translated, and edited from publications not otherwise translated into English under the auspices of the AMS-ASL-IMS Committee on Translations from Russian and Other Foreign Languages

Transcriptional regulation of NOX genes expression in human breast adenocarcinoma MCF-7 cells is modulated by adaptor protein Ruk/CIN85

NADPH oxidases are key components of redox-dependent signaling networks involved in the control of cancer cell proliferation, survival and invasion. The data have been accumulated that demonstrate specific expression patterns and levels of NADPH oxidase homologues (NOXs) and accessory genes in human cancer cell lines and primary tumors as well as modulation of these parameters by extracellular cues. Our previous studies revealed that ROS production by human colorectal adenocarcinoma HT-29 cells is positively correla­ted with adaptor protein Ruk/CIN85 expression while increased levels of Ruk/CIN85 in weakly invasive human breast adenocarcinoma MCF-7 cells contribute to their malignant phenotype through the constitutive activation of Src/Akt pathway. In this study, to investigate whether overexpression of Ruk/CIN85 in MCF-7 cells can influence transcriptional regulation of NOXs genes, the subclones of MCF-7 cells with different levels­ of Ruk/CIN85 were screened for NOX1, NOX2, NOX3, NOX4, NOX5, DUOX1 and DUOX2 as well as for regulatory subunit p22Phox mRNA contents by quantitative RT-PCR (qPCR). Systemic multidirectional changes in mRNA levels for NOX1, NOX2, NOX5, DUOX2 and p22Phox were revealed in Ruk/CIN85 overexpressing cells in comparison to control WT cells. Knocking down of Ruk/CIN85 using technology of RNA-interference resulted in the reversion of these changes. Further studies are necessary to elucidate, by which molecular mechanisms Ruk/CIN85 could affect transcriptional regulation of NOXs genes