Homo sapiens
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PROVIDER: PRJNA242805 | ENA |
REPOSITORIES: ENA
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Project description:Purpose: Irinotecan (SN38) and oxaliplatin are chemotherapeutic agents used in the treatment of colorectal cancer. However, the frequent development of resistance to these drugs represents a considerable challenge in the clinic. Alus as retrotransposons comprise 11% of the human genome. Genomic toxicity induced by carcinogens or drugs can reactivate Alus by altering DNA methylation. Whether or not reactivation of Alus occurs in SN38 and oxaliplatin resistance remains unknown. Methods: We applied reduced representation bisulfite sequencing (RRBS) to investigate the DNA methylome in SN38- or oxaliplatin-resistant colorectal cancer cell line models. Moreover, we extended the RRBS analysis to tumor tissue from 14 patients with colorectal cancer who either did or did not benefit from capecitabine + oxaliplatin treatment. For the clinical samples, we applied a concept of DNA methylation entropy to estimate the diversity of DNA methylation states of the identified resistance phenotype-associated methylation loci observed in the cell line models. Results: We identified different loci being characteristic for the different resistant cell lines. Interestingly, 53% of the identified loci were Alu sequences -- especially the Alu Y subfamily. Furthermore, we identified an enrichment of Alu Y sequences that likely results from increased integration of new copies of Alu Y sequence in the drug-resistant cell lines. In the clinical samples, SOX1 and other SOX gene family members were shown to display variable DNA methylation states in their gene regions. The Alu Y sequences showed remarkable variation in DNA methylation states across the clinical samples. Our findings imply a crucial role of Alu Y in colorectal cancer drug resistance. Our study underscores the complexity of colorectal cancer aggravated by mobility of Alu elements and stresses the importance of personalized strategies, using a systematic and dynamic view, for effective cancer therapy. Investigation of the representive methylome of well-established SN38 and Oxaliplatin resistant cell line models and 14 clinical colorectal metastatic samples that have developed resistance to XELOX to review the epigenetic mechnism of the drug resistance.
2015-04-01 | E-GEOD-56269 | biostudies-arrayexpress
Project description:Purpose: Irinotecan (SN38) and oxaliplatin are chemotherapeutic agents used in the treatment of colorectal cancer. However, the frequent development of resistance to these drugs represents a considerable challenge in the clinic. Alus as retrotransposons comprise 11% of the human genome. Genomic toxicity induced by carcinogens or drugs can reactivate Alus by altering DNA methylation. Whether or not reactivation of Alus occurs in SN38 and oxaliplatin resistance remains unknown. Methods: We applied reduced representation bisulfite sequencing (RRBS) to investigate the DNA methylome in SN38- or oxaliplatin-resistant colorectal cancer cell line models. Moreover, we extended the RRBS analysis to tumor tissue from 14 patients with colorectal cancer who either did or did not benefit from capecitabine + oxaliplatin treatment. For the clinical samples, we applied a concept of DNA methylation entropy to estimate the diversity of DNA methylation states of the identified resistance phenotype-associated methylation loci observed in the cell line models. Results: We identified different loci being characteristic for the different resistant cell lines. Interestingly, 53% of the identified loci were Alu sequences -- especially the Alu Y subfamily. Furthermore, we identified an enrichment of Alu Y sequences that likely results from increased integration of new copies of Alu Y sequence in the drug-resistant cell lines. In the clinical samples, SOX1 and other SOX gene family members were shown to display variable DNA methylation states in their gene regions. The Alu Y sequences showed remarkable variation in DNA methylation states across the clinical samples. Our findings imply a crucial role of Alu Y in colorectal cancer drug resistance. Our study underscores the complexity of colorectal cancer aggravated by mobility of Alu elements and stresses the importance of personalized strategies, using a systematic and dynamic view, for effective cancer therapy.
2015-04-01 | GSE56269 | GEO
Project description:The aim of this study was to identify biomarkers of drug response and investigate mechanisms of drug resistance to the two chemotherapeutic drugs oxaliplatin and irinotecan (active metabolite SN-38) in colorectal cancer, using a cell-based model system of drug-sensitive parental colon cancer cell lines and sub-cell lines with acquired drug resistance.
2015-03-15 | GSE42387 | GEO
Project description:Patients with advanced colorectal cancer (CRC) are commonly treated with systemic combination therapy but suffer eventually from drug resistance. MicroRNAs (miRNAs) are suggested to play a role in treatment resistance of CRC. We studied whether restoring downregulated miR-195-5p and 497-5p sensitize CRC cells to currently used chemotherapeutics 5-fluorouracil, oxaliplatin and irinotecan. Sensitivity to 5-FU, oxaliplatin and irinotecan before and after transfection with miR-195-5p and miR-497-5p mimics was analyzed in CRC cell lines HCT116, RKO, DLD-1 and SW480. Mass spectrometry based proteomic analysis of transfected and wild-type cells was used to identify targets involved in sensitivity to chemotherapy. Proteomic analysis revealed 181 proteins with significantly altered expression after transfection with miR-195-5p mimic in HCT116 and RKO, including 118 downregulated and 63 upregulated proteins. After transfection with miR-497-5p mimic, 130 proteins were significantly downregulated and 102 were upregulated in HCT116 and RKO (P<0.05 and FC<-3 or FC>3). CHUK and LUZP1 were coinciding downregulated proteins in sensitized CRC cells after transfection with either mimic. Resistance mechanisms of these two proteins may be related to nuclear factor kappa-B signaling and G1 cell cycle arrest, respectively. Restoring miR-195-5p and miR-497-5p expression enhanced sensitivity to chemotherapy, mainly oxaliplatin, in CRC cells and could be a promising treatment strategy for patients with mCRC. Proteomics revealed potential targets of these miRNAs involved in sensitivity to chemotherapy.
2019-09-27 | PXD015369 | Pride
Project description:Metastatic colorectal cancer (mCRC) is associated with multiple somatic copy number alterations (SCNAs). We analyzed SCNAs to estimate overall survival (OS) and progression free suvival (PFS) for mCRC patients treated with bevacizumab in combination with oxaliplatin or irinotecan.
2018-11-21 | GSE110785 | GEO
Project description:Irinotecan, an analogue of camptothecin, is frequently used in combination with various anticancer drugs or as a single agent in treatment of colorectal cancer. But drug resistance of tumor is still a major obstacle to overcome for the success of cancer treatment. In this study, We established chronic irinotecan resistant cell line for new marker to increase the sensitivity to irinotecan and investigated gene expression profiles of the irinotecan-resistant colorectal cancer cell line.
2014-07-18 | GSE59501 | GEO
Project description:Irinotecan, an analogue of camptothecin, is frequently used in combination with various anticancer drugs or as a single agent in treatment of colorectal cancer. But drug resistance of tumor is still a major obstacle to overcome for the success of cancer treatment. In this study, We established chronic irinotecan resistant cell line for new marker to increase the sensitivity to irinotecan and investigated gene expression profiles of the irinotecan-resistant colorectal cancer cell line. To create stable CRC cell line chronically resistant to Irinotecan, LoVo cell was exposed to an initial Irinotecan concentration of 0.1 M-NM-<mol/L in RPMI 1640 supplemented with 10% FBS. When the growth of the cultured cells reaches at 80% confluency, cells were passaged twice at same drug concentration to ensure adaptation and then concentration of Irinotecan was sequentially increased in the same manner to 8 M-NM-<mol/L and then we investigated the gene expressions between parental colorectal cancer cell line, LoVo and Irinotecan resistant LoVo cell lines
2014-07-18 | E-GEOD-59501 | biostudies-arrayexpress
Project description:Identificaiton of novel single-nucleotide polymorphism (SNP) candidates associated with chemo-responsiveness in colorectal cancers using microarray Response rates of 104 colorectal cancer patients to established regiments (FL, CAPE, FLOX, FLIRI) were evaluated by histoculture drug response assay. Affymetrix SNP 5.0 chips were used to determine genotypes of the same colorectal cancer patients. SNPs associated with chemosensitivity to standard regimens were identified by genome-wide association study. FL: 5-FU + Leucovorin; CA: Capecitabine, FLOX: 5-FU + Leucovorin + Oxaliplatin, FLIRI: 5-FU + Leucovorin + Irinotecan
2010-06-01 | GSE16718 | GEO
Project description:Oxaliplatin (L-OHP) serves as a standard chemotherapy for colorectal cancer, while the drug resistance is still a considerable challenge. Dysregulation of lncRNA is involved in cancer and recent translatomics has found some alleged lncRNA actually contained small open reading frames and could encode short peptides. This ribosome footprint profiling (Ribo-seq) was a paired-end sequencing and aimed to investigate whether lncRNA could regulate oxaliplatin resistance in colorectal cancer by encoding short peptides.
2021-11-12 | E-MTAB-10805 | biostudies-arrayexpress
Project description:Oxaliplatin (L-OHP) serves as a standard chemotherapy for colorectal cancer, while the drug resistance is still a considerable challenge. A number of previously unknown transcripts have been identified in recent years, the vast majority of which are considered long non-coding RNA (lncRNA). Dysregulation of the lncRNA is involved in the genesis and progression of cancer. This RNA-seq was a paired-end sequencing and aimed to investigate the expression profile of lncRNA associated with oxaliplatin resistance in colorectal cancer.
2021-11-12 | E-MTAB-10806 | biostudies-arrayexpress