Glioblastoma (GBM), the most common type of malignant brain cancer, is uniformly fatal despite ongoing research into the development of novel therapeutics. One reason for the high lethality of GBM is the presence of a self-renewing population of cells that is resistant to chemo- and radiation therapy, termed cancer stem cells (CSCs). Although the cancer stem cell hypothesis remains controversial, we and others have shown that directly targeting this population of cells decreases tumor growth and initiation and sensitizes tumors to current clinical therapies. Cellular interactions within the CSC compartment and between CSCs and non-CSCs help maintain the balance between CSC self-renewal and differentiation. Direct cell interactions may also allow cells to rapidly adapt in response to tumo growth and the presence of chemotherapeutics. Gap junctions, one type of cell-cell contact mechanism, are composed of connexin subunits that form connexon channels, which allow the transport of small molecules from cell to cell. The translational goal of this project is to conduc mechanistic studies into the role of cell-cell interactions in the progression of GBM. We hypothesize that cell type-specific communication is controlled by a balance of connexin subunits and that disrupting this balance attenuates GBM progression. We will interrogate this hypothesis by investigating the following aims: 1) that the balance between connexin subunits exerts differential effects on CSCs, non-CSCs, and normal neural cells; 2) that Cx46 contributes to CSC maintenance; and 3) that in vivo targeting of connexin subunits attenuates GBM progression. The long-term goal of this project is to translate the information gained about direct cell-cell communication in GBM to inhibition strategies useful as clinical therapies.
Advances in cancer treatment have thus far failed to successfully treat glioblastoma patients or extend survival beyond the median 12-15 months. The severity of glioblastoma is due at least in part to a self-renewing population of chemo- and radio-resistant cells termed cancer stem cells. Communication within the cancer stem cell population and between stem cells and non-stem cells may be a novel mechanism against which to direct next-generation therapies.
|Silver, Daniel J; Lathia, Justin D (2018) Therapeutic Injury and Tumor Regrowth: Tumor Resection and Radiation Establish the Recurrent Glioblastoma Microenvironment. EBioMedicine 31:13-14|
|Mesnil, Marc; Aasen, Trond; Boucher, Jonathan et al. (2018) An update on minding the gap in cancer. Biochim Biophys Acta Biomembr 1860:237-243|
|Silver, Daniel J; Lathia, Justin D (2018) Revealing the glioma cancer stem cell interactome, one niche at a time. J Pathol 244:260-264|
|Saygin, Caner; Wiechert, Andrew; Rao, Vinay S et al. (2017) CD55 regulates self-renewal and cisplatin resistance in endometrioid tumors. J Exp Med 214:2715-2732|
|Thiagarajan, Praveena S; Zheng, Qiao; Bhagrath, Manvir et al. (2017) STAT3 activation by leptin receptor is essential for TNBC stem cell maintenance. Endocr Relat Cancer 24:415-426|
|Alvarado, Alvaro G; Thiagarajan, Praveena S; Mulkearns-Hubert, Erin E et al. (2017) Glioblastoma Cancer Stem Cells Evade Innate Immune Suppression of Self-Renewal through Reduced TLR4 Expression. Cell Stem Cell 20:450-461.e4|
|Wiechert, Andrew; Saygin, Caner; Thiagarajan, Praveena S et al. (2016) Cisplatin induces stemness in ovarian cancer. Oncotarget 7:30511-22|
|Otvos, Balint; Silver, Daniel J; Mulkearns-Hubert, Erin E et al. (2016) Cancer Stem Cell-Secreted Macrophage Migration Inhibitory Factor Stimulates Myeloid Derived Suppressor Cell Function and Facilitates Glioblastoma Immune Evasion. Stem Cells 34:2026-39|
|Hitomi, Masahiro; Deleyrolle, Loic P; Mulkearns-Hubert, Erin E et al. (2015) Differential connexin function enhances self-renewal in glioblastoma. Cell Rep 11:1031-42|