Project description:Oxaliplatin resistance frequently leads to therapeutic failure in colorectal cancer (CRC). Increasing evidence has shown that noncoding RNAs (ncRNAs) play pivotal roles in chemoresistance of CRC. However, the roles and mechanisms of ncRNAs in oxaliplatin resistance are not well understood. In this study, to identify the ncRNAs induced by oxaliplatin, we profile the expression of ncRNAs in oxaliplatin-resistant HCT116 CRC cells (HCT116oxR) and parental HCT116 cells using next-generation sequencing technology.
Project description:Resistance to chemotherapy drugs, including oxaliplatin, remains a major challenge in the treatment of colorectal cancer, often leading to treatment failure and poor patient outcomes. Overcoming chemoresistance by sensitizing tumor cells represents a critical therapeutic goal. Adenoviral early region 1A (E1A) has been proposed as a promising gene therapy agent capable of modulating cellular pathways to enhance sensitivity to chemotherapeutic agents. This dataset contains RNA-seq profiling of human colorectal cancer cell lines that are either oxaliplatin-sensitive (HCT116) or oxaliplatin-resistant (HCT116 oxpl-R), treated with oxaliplatin, in the context of doxycycline-induced adenoviral E1A expression. The experiment includes eight conditions: untreated controls, E1A expression alone, oxaliplatin treatment alone, and combined E1A expression with oxaliplatin treatment, each in both sensitive and resistant cell lines. The comprehensive experimental design enables the dataset to be divided into three independent analyses: A) Comparison of baseline transcriptomic profiles between oxaliplatin-sensitive and resistant cells (conditions 1 and 5); B) Investigation of the transcriptional response to oxaliplatin in sensitive and resistant cells (conditions 1, 3, 5, and 7); C) Evaluation of the impact of adenoviral E1A expression on the transcriptomes of sensitive and resistant cells alone (conditions 1, 2, 5, and 6) and in combination with oxaliplatin treatment (all eight conditions); This dataset provides valuable insights into the molecular mechanisms underlying oxaliplatin resistance and the potential role of E1A gene therapy in sensitizing colorectal cancer cells to chemotherapy.
Project description:Oxaliplatin resistance was induced in 2 colorectal cancer cell lines (LoVo-92, wt-p53 and LoVo-Li, functionally inactive p53) and one ovarian cancer cell line (A2780, wt-p53). Resistance was induced by weekly exposure to oxaliplatin for 4 hrs or 72 hrs with increasing concentrations for a period of 7 months Genomic DNA of oxaliplatin and cisplatin resistant colorectal cancer and ovarian cancer cell lines as well as the parental cell lines were labeled and subsequently hybridized against pooled reference DNA of healthy volunteers of the opposite gender using across array hybridization. Extracted raw-data were normalised and smoothend using the R-script NOWAVE resulting in normalised log2 ratio profiles of resistant cell line versus parental cell line and parental cell line versus reference DNA.
Project description:To explore the mechanisms associated with oxaliplatin resistance, we compared gene expression in xenograft tumors derived from human colorectal cancer tumor cells HCT116 and its oxaliplatin resistant clones (HCT/OHP1 and HCT/OHP5).
Project description:Oxaliplatin as a first-line drug frequently causes the chemo-resistance on colorectal cancer (CRC). N6-methyladenosine (m6A) methylation has been largely acknowledged in multiple biological functions. However, the molecular mechanisms underlying the m6A methylation in modulating anticancer drug resistance in CRC are still obscure. In present study, RNA-seq was conducted to investigate the transcriptome of HCT116, HCT116 cells with oxaliplatin resistance (HCT116R), HCT8 and HCT8 cells with oxaliplatin resistance (HCT8R).
Project description:Oxaliplatin as a first-line drug frequently causes the chemo-resistance on colorectal cancer (CRC). N6-methyladenosine (m6A) methylation has been largely acknowledged in multiple biological functions. However, the molecular mechanisms underlying the m6A methylation in modulating anticancer drug resistance in CRC are still obscure. In present study, RIP-seq was conducted to investigate the occupancy of N6-methyladenosine RNA binding protein 3 (YTHDF3) served as “readers” that can recognize m6A modification site in HCT116 cells with oxaliplatin resistance (HCT116R). Then, YTHDF3 was knockdown by siRNA in HCT116 cells with oxaliplatin resistance, and RIP-seq was further conducted to investigate m6A methylation of HCT116, HCT116R and HCT116R cells with YTHDF3 knockdown.
Project description:HCT116 parental, HCT116 5-FU resistant and HCT116 oxaliplatin resistant cells have been transiently treated with with their respective drug (5-FU or oxaliplatin) for 0, 6 12 or 24h in 3 independent experiments.
Project description:Platinum-based chemotherapies, including oxaliplatin, are a mainstay in solid tumor treatment and induce cell death by forming intrastrand dinucleotide DNA adducts. Despite their common use, they are highly toxic and approximately half of patients have tumors that are either intrinsically resistant, or that develop resistance. Studies suggest that this resistance is mediated by variations in DNA repair levels or net drug influx. We aimed to better define the roles of nucleotide excision repair and DNA damage formation in platinum resistance by profiling DNA damage levels and repair efficiency in a panel of seven oxaliplatin-sensitive and three oxaliplatin-resistant colorectal cancer cell lines. We assayed repair indirectly as toxicity, and directly measured bulky adduct formation and removal from the genome by slot blot, repair capacity by excision assay, and mapped repair events genome-wide at single nucleotide resolution using XR-Seq. Using this comprehensive approach of combining novel methods and in some cases using proxies for oxaliplatin-DNA damage, we found no significant difference in repair efficiency that could explain the relative sensitivity and resistance of our cell lines. In contrast, the overall levels of oxaliplatin-DNA damage were significantly lower in resistant cells, indicating that decreased formation of damage, rather than increased repair of that damage, is a major determinant of oxaliplatin resistance. Analysis of gene expression using our XR-seq data showed upregulation of membrane transport pathways in resistant cells, and these pathways may contribute to resistance. Additional research is needed to characterize factors mitigating cellular DNA damage formation by platinum compounds.
Project description:Gene expression between DLD1 and DLD1 derived oxaliplatin resistant clones (DLD/OHP1, DLD/OHP4, and DLD/OHP5) was assessed Gene expression between HCT116 and HCT116 derived oxaliplatin resistant clones (HCT/OHP1, HCT/OHP3, and HCT/OHP5) was assessed