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Integrated genetic and metabolic landscapes predict vulnerabilities of temozolomide resistant glioblastoma cells.

ABSTRACT: Metabolic reprogramming and its molecular underpinnings are critical to unravel the duality of cancer cell function and chemo-resistance. Here, we use a constraints-based integrated approach to delineate the interplay between metabolism and epigenetics, hardwired in the genome, to shape temozolomide (TMZ) resistance. Differential metabolism was identified in response to TMZ at varying concentrations in both the resistant neurospheroidal (NSP) and the susceptible (U87MG) glioblastoma cell-lines. The genetic basis of this metabolic adaptation was characterized by whole exome sequencing that identified mutations in signaling pathway regulators of growth and energy metabolism. Remarkably, our integrated approach identified rewiring in glycolysis, TCA cycle, malate aspartate shunt, and oxidative phosphorylation pathways. The differential killing of TMZ resistant NSP by Rotenone at low concentrations with an IC₅₀ value of 5?nM, three orders of magnitude lower than for U87MG that exhibited an IC₅₀ value of 1.8?mM was thus identified using our integrated systems-based approach.

SUBMITTER: Immanuel SRC

PROVIDER: S-EPMC7794364 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature

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Integrated genetic and metabolic landscapes predict vulnerabilities of temozolomide resistant glioblastoma cells.

Immanuel Selva Rupa Christinal SRC Ghanate Avinash D AD Parmar Dharmeshkumar S DS Yadav Ritu R Uthup Riya R Panchagnula Venkateswarlu V Raghunathan Anu A

NPJ systems biology and applications 20210108 1

Metabolic reprogramming and its molecular underpinnings are critical to unravel the duality of cancer cell function and chemo-resistance. Here, we use a constraints-based integrated approach to delineate the interplay between metabolism and epigenetics, hardwired in the genome, to shape temozolomide (TMZ) resistance. Differential metabolism was identified in response to TMZ at varying concentrations in both the resistant neurospheroidal (NSP) and the susceptible (U87MG) glioblastoma cell-lines. ...[more]

PMID: 33420045

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Project description:BackgroundDoxorubicin is one of the most effective chemotherapeutic drugs for breast cancer while its common drug resistance leads to poor patient prognosis and survival. Growing evidence indicate dynamically reorganized chromatin allows rapid access of the gene regulatory machinery to open genomic regions facilitating subsequent gene expression through direct transcription factor (TF) activation and regulatory element binding.MethodsTo better understand the regulatory network underlying doxorubicin resistance in breast cancer cells, we explored the systematic alterations of chromatin accessibility and gene expression by the assay for transposase-accessible chromatin using sequencing (ATAC-seq) in combination with RNA sequencing, followed by integrative analysis to identify potential regulators and their targets associated with differentially accessible regions (DARs) in doxorubicin-resistant MCF7 (MCF7-DR) cells.ResultsA total of 3,963 differentially expressed genes (DEGs) related to doxorubicin resistance were identified, including dramatically up-regulated MT1E, GSTP1, LDHB, significantly down-regulated TFF1, UBB, DSCAM-AS1, and histone-modifying enzyme coding genes HDAC2, EZH2, PRMT5, etc. By integrating with transcriptomic datasets, we identified 18,228 DARs in MCF7-DR cells compared to control, which were positively correlated with their nearest DEGs (r = 0.6). There were 11,686 increased chromatin-accessible regions, which were enriched in up-regulated genes related to diverse KEGG pathways, such as the cell cycle, regulation of actin cytoskeleton, signaling pathways of MAPK, PI3K/Akt and Hippo, which play essential roles in regulating cell apoptosis, proliferation, metabolism, and inflammatory responses. The 6,542 decreased chromatin-accessible regions were identified for the declined doxorubicin-associated biological processes, for instance, endocrine and insulin resistance, central carbon metabolism, signaling pathways of TGF-beta and P53. Combining data from TCGA, analyses of the DAR sequences associated with the DNA-binding motifs of significantly enriched TF families including AP-1, TEAD and FOX, indicated that the loss-function of FOXA1 might play a critical role in doxorubicin-resistant breast cancer cells (DOX-R BCCs).ConclusionThese data exhibit the non-genetic landscape of chromatin accessibility and transcript levels in the DOX-R BCCs, and provide clear insights and resources for the detection of critical TFs and potential cis-regulatory elements-based putative therapeutic targets.

Project description:Background: 5-Fluorouracil (5-FU) is one of the most effective and widely used chemotherapeutic drugs in the treatment of colon cancer, yet chemoresistance is a common feature of colon cancer treatment, resulting in poor prognosis and short survival. Dynamic reprogramming of chromatin accessibility is crucial for proper regulation of gene transcription associated with cancer drug resistance by providing the gene regulatory machinery with rapid access to the open genomic DNA. Methods: Here, we explored the global chromatin accessibility and transcription changes by the assay for transposase-accessible chromatin using sequencing (ATAC-seq) in combination with transcriptome sequencing of both parental and 5-FU-resistant HCT15 cells, followed by integrative analysis to better understand the regulatory network underlying 5-FU resistance in colon cancer cells. Results: A total of 3,175 differentially expressed mRNAs (DEGs), lncRNAs (DELs), and miRNAs (DEMs) related to 5-FU resistance were identified, including significantly upregulated IL33, H19, and miR-17-5p; the downregulated AKR1B10, LINC01012, and miR-125b-5p; and chromatin modifiers such as INO80C, HDAC6, and KDM5A. The construction of the ceRNA regulatory network revealed that H19, HOXA11-AS, and NEAT1 might function as ceRNAs associated with 5-FU resistance in HCT15 cells. Moreover, 9,868 differentially accessible regions (DARs) were obtained, which were positively (r = 0.58) correlated with their nearest DEGs and DELs. The upregulated genes related to 4,937 hyper-accessible regions were significantly enriched in signaling pathways of MAPK, FOX, and WNT, while the 4,931 hypo-accessible regions were considered to be involved in declined biosynthesis of amino acids and nucleotide sugars, signaling pathways of Notch, and HIF-1. Analyses of the DAR sequences revealed that besides the AP-1 family, the TF motifs of FOX and KLF family members were highly enriched in hyper- and hypo-accessible regions, respectively. Finally, we obtained several critical TFs and their potential targets associated with DARs and 5-FU resistance, including FOXA1 and KLF3. Conclusion: These data provided clear insights and valuable resources for an improved understanding of the non-genetic landscape of 5-FU-resistant colon cancer cells based on chromatin accessibility and transcript levels, which allowed for genome-wide detection of TF binding sites, potential cis-regulatory elements and therapeutic targets.

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Integrated genetic and metabolic landscapes predict vulnerabilities of temozolomide resistant glioblastoma cells.

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Integrated genetic and metabolic landscapes predict vulnerabilities of temozolomide resistant glioblastoma cells.

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