The role of PKD2 in HSP90,- hypoxia- and TGF beta-mediated epithelial-to-mesenchymal transition and metastasis

• Applicant: Dr. Ninel Azoitei
• Subject Area: Hematology, Oncology
• Term: from 2013 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 232091324

The proposal focuses on the investigation of protein kinase D2s contribution to epithelial-to-mesenchymal transition (EMT), a process implicated in tumor metastasis and initiated by multiple factors such as hypoxia, transcription factors or growth factors. The investigations detailed in the second proposal of the running grant will engage meticulous cellular models dedicated to studying EMT. Detailed morphologic analysis of tumor cells cultivated on porous support and/or 3D collagen gels will be corroborated with various biochemical, immunofluorescence and immunohistochemical analysis. The in vitro experiments will be substantiated by human tumor xenograft on CAM as well as analysis of EMT protein markers on tumors xenografted in nude mice, already available from the previous project. Furthermore, the in vivo contribution of PKD2 to the metastatic potential of mammary cancer cells will be delineated in new experiments with immunodeficient athymic mice. Investigations assessing the role of PKD2 during EMT will contribute to the broadening of our knowledge with respect to the requirement of kinase for other aspects of tumorigenesis, unknown so far for this kinase. The proposed work program will bring insight to participation of PKD2 to EMT initiated and maintained by TGF-beta, HSP90 chaperone and hypoxia. Answering whether PKD2 regulates EMT via the same molecular mechanism/s that govern tumor angiogenesis (e.g. via HIF-1 alpha), or whether the kinase is implicated in other potential signaling pathways that favor the transition of epithelial cancer cells to a mesenchymal phenotype will represent a central focus of the extension proposal. Several microarrays assessing PKD2 involvement in the regulation of several crucial molecules (targeted by NF- kappa B, but not only) reported to emanate signals to induce EMT as well as the planned Mass spectrometry-based interactome on hypoxic cancer cells that undergo EMT will not only serve the current work program, but will also help investigations beyond this proposal. Finally, the use of HSP90-inhibitor PU-H71 (currently in clinical development) will promote our findings for a conceivable use in an immediate therapeutic approach targeting PKD2 stability in particularly hypoxic human tumors.

• DFG Programme: Research Grants