Project description:Patients diagnosed with glioblastoma (GBM) with sustained synthesis of the DNA repair enzyme, O6-methyl guanine DNA methytransferase (MGMT), are rendered resistant to Temozolomide (TMZ) chemotherapy. Here, we hypothesized that pretreatment with the proteasome inhibitor Bortezomib (BTZ, Velcade) might sensitize these GBM to TMZ by depleting MGMT.
Project description:Glioblastoma (GBM) is the most common primary brain tumor in adults with a median survival of 11-12 months. Standard therapy consists of radiotherapy (RT) plus chemotherapy with Temozolomide (TMZ), and no alternative treatment is available. We assessed changes in tumor microenvironment (TME) after RT associated with TMZ and metformin (MET) in a syngenic murine GBM model using single-cell RNA-sequencing (scRNA-seq). RT induced an enrichment of GO annotation related with cell cycle, translation and ribosome biogenesis in all tumor clusters, except the radio resistant one where an increase in the inflammatory phenotype was observed. Resident GAM were reduced after RT alone and differentially modulated by RT-drug combinations. After RT alone, we detected an increase in GAM markers and a downregulation of glycolytic metabolism in both microglial and peripheral macrophage subclusters. Association of TMZ increased the pro-inflammatory phenotype of some GAM clusters in comparison to RT. A different signature was observed for the TMZ-MET association but limited to peripheral infiltrating GAM.
Project description:To determine whether gene expression profiles from peripheral whole blood could be used to determine therapeutic outcome in a cohort of children with newly diagnosed polyarticular JIA.
Project description:We report the application of RNA-based sequencing technology for high-throughput profiling of T cell enriched peripheral blood mononuclear cells. By sequencing in total of 12 pairs GBM patient samples, we extracted TCRαβ V(D)J sequences from the deep RNA-seq of T cells isolated from the 24 PBMCs to determine if TTFields treatment affected TCR diversity, using the Simpson’s diversity index (DI), which is the average proportional abundance of TCR clones based on the weighted arithmetic mean. Of the 12 patients, 9 exhibited negative log fold change (logFC) of TCR DI after TTFields, indicating clonal expansion. Notably, in all but 1 patient, the top 200 most abundant clones post TTFields, which accounted for 38.1% to 100% (median 67%) of detectable clones, showed substantial expansion compared to pre-TTFields T cells, and inversely correlated with the DI. Thus, TTFields treatment is associated with adaptive immune activation as evidenced by clonal expansion of peripheral T cells.
Project description:Despite multi-model therapy of maximal surgical resection, radiation, chemotherapy, and tumor-treating fields, glioblastoma patients show dismal prognosis. Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation Protein Arginine Methyltransferase 5 (PRMT5) is overexpressed in glioblastoma and its inhibition imparts an anti-tumor effect. Even though Temozolomide (TMZ) is the standard chemotherapeutic agent in the treatment of glioblastoma, tumor cells invariably develop resistance to TMZ. However, the mechanistic role of PRMT5 in glioblastoma therapy resistance is unknown. Methods: Patient-derived primary glioblastoma neurospheres (GBMNS), treated with PRMT5 inhibitor (LLY-283) or transfected with PRMT5 target-specific siRNA were treated with TMZ and subjected to in vitro functional and mechanistic studies. The intracranial mouse xenograft model was used to test the in vivo antitumor efficacy of combination treatment. Results: We found that PRMT5 inhibition increased the cytotoxic effect and caspase 3/7 activity of TMZ in GBMNS suggesting that apoptosis is the potential mode of cell death in the combination treatment. PRMT5 inhibition abrogated the TMZ-induced G2/M cell cycle arrest. Unbiased transcriptomic studies indicate that PRMT5 inhibition negatively enriches DNA damage repair genes. Importantly, combination therapy increased DNA double-strand breaks (ɣH2AX foci) and enhanced the DNA damage (comet assay), suggesting that the combination treatment increases the TMZ-induced DNA damage. Specifically, the LLY-283 treatment blocked homologous recombination repair in GBMNS. In vivo, LLY-283 and TMZ combination significantly curbed the tumor growth and prolonged the survival of tumor-bearing mice. Conclusion: Concomitant treatment of LLY-283 and TMZ has significantly greater antitumor efficacy, suggesting that PRMT5 inhibition and TMZ combination could be a new therapeutic strategy for glioblastoma.
Project description:Glioblastoma multiforme(GBM) is the most common and lethal malignant primary brain tumor. Temozolomide (TMZ) is a promising chemo-therapeutic agent to treat GBM. However, resistance to TMZ develops quickly with a high frequency. The mechanisms underlying GBM cells’ resistance to TMZ are not fully understood. Non-coding RNAs are aberrantly expressed in many cancers and are highly involved in their pathogenesis including drug-resistence. In order to systematically study the role of miRNAs in GBM cells' resistence to TMZ , we built gene expression profiles of TMZ-resistant cell line and TMZ-sensitive cell line using miRNA gene expression microarrays.
