Abstract 2702: The mTOR complex 2-associated interactome and cell migration ability determination in brain cancers

Abstract

Abstract The mechanistic target of rapamycin complex 2 (mTORC2) is a multiprotein complex driving several cellular processes to promote metabolic activities, cell survival, cell proliferation, DNA damage control, and cell motility. It has been implicated as a critical player in tumorigenesis, metabolic reprogramming, and promotion of cancer aggressiveness. Since the functions of this particular complex have not been well understood, the characterization of mTORC2 and its signaling pathway is necessary for better understanding of known mTORC2-mediated function, to define new roles, and to identify more mTORC2 interacting partners in cancers, particularly ones with hyperactivated mTORC2 such as glioblastoma multiforme. GBM has been claimed as one of the most aggressive type cancers. In GBM cells, mTORC2 was reported to be regulating glioblastoma migration and invasion through the control of actin cytoskeleton reorganization and filamin A. Previously, we characterized mTORC2 by proteomic analysis using affinity purification coupled to mass spectromytry (AP-MS) technique. We were able to identify protein-protein interactions between RICTOR, a specific component of mTORC2, and associated proteins and revealed a number of mTORC2 interacting partners that have never been reported. These proteins include low-abundance proteins and less-characterized proteins. In this work, we further investigated more insights about the differences of mTORC2-associated interactomes under various conditions affecting cancer cell migration. We found the comparison between low-grade and high-grade glioma cell lines shows distinct groups of RICTOR-bound proteins. In addition, we have carried out migration assays and immunofluorescence staining experiments to determine cancer cell migration and localization of RICTOR and some of identified proteins under each culture condition. The results suggested that the information from proteomic analysis correlated with intracellular RICTOR localization and cell migration ability. EMT proteins and more cytoskeletal proteins were found in more motile and more invasive cells while nuclear proteins were identified when using low-grade glioma cells. Furthermore, we were able to use this approach to investigate cancer cell lines from other organs and found some relevance between mTORC2 complex localization and cell migration. Ultimately, these results will be analyzed together with the expression of other potential cancer markers to help determine the characteristics of brain cancers. Citation Format: Naphat Chantaravisoot, Piriya Wongkongkathep, Narawit Pacharakullanon, Fuyuhiko Tamanoi, Joseph A. Loo, Trairak Pisitkun. The mTOR complex 2-associated interactome and cell migration ability determination in brain cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2702.