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.
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. Long non-coding RNAs (lncRNAs) are aberrantly expressed in many cancers and are highly involved in their pathogenesis including drug-resistence. In order to systematically study the role of lncRNAs in GBM cells' resistence to TMZ , we built gene expression profiles of TMZ-resistant cell line and TMZ-sensitive cell line using lncRNA and mRNA gene expression microarrays.
Project description:Glioblastoma (GBM) is an aggressive brain cancer that is notoriously resistant to chemotherapy, particularly to Temozolomide (TMZ). In this study, we examined a patient-derived TMZ-resistant GBM cell line and assessed the effects of the PARP inhibitor Olaparib. We observed that while Olaparib exhibited significant tumor inhibition, its required dosage exceeded clinically acceptable levels. Transcriptomic analysis revealed a notable upregulation of nicotinamide phosphoribosyltransferase (NAMPT) in the surviving tumor cells, suggesting that increased intracellular NAD+ levels contributed to their resistance against both Olaparib and TMZ. By optimizing the dosages of Olaparib and FK866, a NAMPT inhibitor, we were able to develop a combination therapy that effectively killed TMZ-resistant GBM cells while adhering to clinically applicable pharmacodynamic and toxicological standards for each drug. This combination was also tested across other TMZ-resistant cell lines and 3D organoids, showing promising potential for clinical application. Additionally, through profiling plasma-detectable circRNA species from the combination treatment, we identified circPTTG1IP as a potential biomarker with negative predictive value. Further analysis indicated that circPTTG1IP might regulate NAMPT expression and NAD+ levels, potentially through its interaction with miRNAs targeting NAMPT. This research provides insights into a novel therapeutic strategy for overcoming TMZ resistance in GBM.
Project description:cell culture:The human glioma cell line U87MG was obtained from the Cell Resource Center, Peking Union Medical College (Beijing, China), and U251MG was acquired from the American Type Culture Collection (Manassas, VA). Temozolomide (TMZ) resistant U87MG cells (U87TR) and TMZ resistant U251MG cells (U251TR) of glioblastoma (GBM) sub-cell lines, were established through repetitive exposure to increasing TMZ concentrations in vitro in our laboratory. Cells were cultured in DMEM culture medium supplemented with 10% FBS with a standard humidified incubator under 5% CO2 at 37°C.