Project description:Glioblastoma (GBM) is the most common lethal primary brain cancer in adults. Despite treatment regimens including surgical resection, radiotherapy, and temozolomide (TMZ) chemotherapy, growth of residual tumor leads to therapy resistance and death. At recurrence, a quarter to a third of all gliomas have hypermutated genomes 5, with mutational burdens orders of magnitude greater than in normal tissue. Here, we quantified the mutational landscape progression in a patient’s primary and recurrent GBM, and uncovered Cas9-targetable repeat elements. We show that CRISPR-mediated targeting of highly repetitive loci enables rapid elimination of GBM cells, an approach we term “Genome Shredding”. Importantly, in the patient’s recurrent GBM, we identified unique repeat sequences with TMZ mutational signature and demonstrate that their CRISPR targeting enables cancer-specific cell ablation. “Cancer Shredding” leverages the non-coding genome and therapy-induced mutational signatures for targeted GBM cell depletion and provides an innovative paradigm to develop treatments for hypermutated glioma.
Project description:Treating recurrent GBM is a clinical challenge due to its highly resistant and aggressive nature. In order to develop new therapeutic targets for recurrent GBM a better understanding of its molecular landscape is necessary. Here we used a cellular model, developed in our lab which generates paired primary and recurrent samples from GBM cell lines and primary patient samples hence allowing us to compare the molecular differences between the two populations. Total RNA seq analysis of parent and recurrent population of two cell lines and one patient sample revealed a significant upregulation of Extracellular matrix interaction in recurrent population. Since matrix stiffness plays a pivotal role in cell-ECM interaction and downstream signaling, we developed a system that mimicked the brain like substrate stiffness by using collagen coated polyacrylamide-based substrate whose stiffness can be modified from normal brain (0.5kPa) to tumorigenic (10kPa). Using these substrates, we were able to capture the morphological and physiological differences between parent and recurrent GBM which were not evident on plastic surfaces (~1 GPa). On 0.5kPa, unlike circular parent cells, recurrent GBM cells showed two morphologies (circular and elongated). The recurrent cells growing on 0.5kPa also showed higher proliferation, invasion, migration and in-vivo tumorigenicity in orthotropic GBM mouse model, compared to parent cells. Furthermore, recurrent cells exhibited elevated velocity irrespective of substrate stiffness, which indicated that recurrent cells may possess inherent differential mechanosignalling ability which was reflected by higher expression of ECM proteins like Collagen IVA, MMP2 and MMP9. Moreover, mice brain injected with recurrent cells grown on 0.5kPa substrate showed higher Young’s modulus values suggesting that recurrent cells conditioned on 0.5kPa make the surrounding ECM stiffer. Importantly, inhibition of EGFR signaling, that is amplified with tissue stiffening in GBM resulted in decreased invasion, migration and proliferation in 0.5kPa recurrent cells, but interestingly survival remained unaffected, highlighting the importance of mimicking the physiological stiffness of the brain mimicking clinical scenario. Total RNA seq analysis of parent and recurrent cells grown on plastic and 0.5kPa substrate identified PLEKHA7 as significantly upregulated gene specifically in 0.5kPa recurrent sample. Higher protein expression of PLEKHA7 in recurrent GBM as compared to primary GBM was validated in patient biopsies. Accordingly, PLEKHA7 knockdown reduced invasion and survival of recurrent GBM cells. Together, these data provides a model system that captures the differential mechanosensing signals of primary and recurrent GBM cells and identifies a novel potential target specific for recurrent GBM.
Project description:The goals of WGS (Whole Genome Sequencing) analysis in TJ46 cells derived from a GBM primary tissue to obtain information on the genetic alterations that characterize this model.
Project description:Glioblastoma (GBM) bears a dismal prognosis with rapid relapse following complete resection and radiochemotherapy. The involvement of microRNAs in tumor progression has been demonstrated in hepatoma, breast cancer, and prostate cancers. However, the microRNAs involved in modulating the progression and relapse of GBM are still unclear. Initially, we compared the miRNA expression profiles between primary and recurrent GBM tissues from the same patient in twelve independent cases. miRNA expression profiles between primary and recurrent GBM tissues from the same patient in twelve independent cases.
Project description:The 12 recurrent GBM patients were participated. NanoString nCounter pancancer IO 360 panel (750 genes) assay was conducted with GBM patients tissue which was extracted at postoperative after recurrent event. The goal of this study was to extract significant genes which were associated with overall survival (OS) and durable response within AKC-treated recurrent GBM patients.
Project description:Glioblastoma multiforme (GBM) is the most lethal brain malignant neoplasm, associated with poor prognosis and high recurrence. The mechanisms involved in GBM development and recurrent remains largely unknown. Hence, it’s considerably imperative to explore the potential targets and unravel the mechanism implicated in GBM tumorigenesis and recurrence. In our study, mass spectrometry-based label-free quantitative proteomics was employed to explore the proteomic profiling in non-paired samples of primary and recurrent GBM. Bioinformatic analysis of differentially expression proteins (DEPs) were applied to screen the hub genes. Subsequently, hub genes expression was verified by western blot and immunohistochemistry (IHC) in GBM tissues, followed by its biological effect on GBM at a cellular level determined. We contoured the divergent landscape of proteome between primary and recurrent GBM, with only ten overlapped DEPs included. The several hub genes screened (e.g., CKAP4 and CANX) and enriched pathways correlated with primary GBM such as post-translation, metabolism, energy pathways and cell growth were profiled. Furthermore, CKAP4 was implicated in proliferation, migration and invasion of A172 and T98G cell lines. However, UQCRC1, together with relative enriched pathways such as oxidative phosphorylation, were screened in recurrent GBM. Establishment of the proteomics and several candidate proteins identified could pose considerable access to understand complex biochemical processes and obtain a better picture of GBM biology.
Project description:Chronic myeloid leukemia (CML) epitomizes successful targeted therapy, with 86% of patients in the chronic phase treated with tyrosine kinase inhibitors (TKIs) attaining remission. However, resistance to TKIs occurs during treatment, and patients with resistance to TKIs progress to the acute phase called Blast Crisis (BC), wherein the survival is restricted to 7-11 months. About 80 % of patients in BC are unresponsive to TKIs. This issue can be addressed by identifying a molecular signature which can predict resistance in CML-CP prior to treatment as well as by delineating the molecular mechanism underlying resistance. Herein, we report genomic analysis of CML patients and imatinib-resistant K562 cell line to achieve the same. WGS was performed on imatinib-sensitive and -resistant K562 cells. Library preparation was done by 30x WGS KAPA PCR-Free v2.1 kit, and Illumina HiSeq X sequencer was used for 2 x 150 bp paired-end sequencing. Our study identified accumulation of aberrations on chromosomes 1, 3, 7, 16 and 22 as predictive of occurrence of resistance. Further, recurrent amplification in chromosomal region 8q11.2-12.1 was detected in highly resistant K562 cells as well as CML patients. The genes present in this region were analyzed to understand molecular mechanism of imatinib resistance.
Project description:Glioblastoma (GBM) bears a dismal prognosis with rapid relapse following complete resection and radiochemotherapy. The involvement of microRNAs in tumor progression has been demonstrated in hepatoma, breast cancer, and prostate cancers. However, the microRNAs involved in modulating the progression and relapse of GBM are still unclear. Initially, we compared the miRNA expression profiles between primary and recurrent GBM tissues from the same patient in twelve independent cases.
Project description:Background: Glioblastoma (GBM) is a common malignancy of the central nervous system (CNS) that is prone to recurrent and has a short survival period. Clinical biomarkers for the diagnosis and prognosis of recurrent GBM are lacking.Methods: We collected 4 cerebrospinal fluid (CSF) samples and 1 normal CSF sample from recurrent GBM, as well as paired tissue samples. Genome-wide methylation profiles of CSF circulating tumor DNA (ctDNA) and tissue mRNA transcription profiles were analyzed, and genes were screened by univariate Cox analysis, Lasso regression analysis, and multivariate Cox analysis by the Chinese Glioma Genome Atlas (CGGA) database. Data analysis and visualization were performed using R software, SPSS software, and Graphpad Prism.Results: By taking the intersection of differentially methylated regions (DMRs) and differentially expressed genes (DEGs), 892 genes were selected for Lasso regression analysis and multivariate Cox analysis, and 12 hub genes were finally screened to construct diagnostic and prognostic models. The diagnostic (AUC=0.982) and prognostic (5-years AUC=0.931) models based on the 12 hub genes had high accuracy.Conclusions: This study reveals that 12 hub genes in CSF ctDNA can diagnose and prognosticate recurrent GBM and provide new biomarkers for clinical research into the mechanisms of GBM recurrent.