Project description:To screen for epigenetically silenced miRNAs, wecarried out miRNA microarray analysis in three colorectal cancer (CRC) cell lines (HCT116, DLD-1 and RKO) treated with or without 5-aza-2'-deoxycytidine (aza). HCT116 and RKO cells were also treated with aza plus 4-phenylbutyric acid (PBA). In addition, we analyzed HCT116 cells in which the DNA methyltransferase genes DNMT1 and DNMT3B were genetically disrupted (double knockout; DKO cells), thereby abrogating DNA methylation. Expression of a majority of miRNAs was downregulated in all three CRC cell lines tested, as compared to normal colonic mucosa. DAC treatment upregulated expression of a large number of miRNAs in all three CRC cell lines, and combination treatment with DAC plus PBA induced even greater numbers of miRNAs in CRC cells. The most profound effect on the miRNA expression profile was induced by genetic disruption of DNMT1 and DNMT3B in HCT116 cells. CRC cells were treated with 5-aza-2’-deoxycytidine (aza) or aza plus 4-phenylbutyrate (PBA). Nomal colon RNA was purchased from BioChain. Expression of 470 miRNAs was analyzed using Human miRNA Microarray V1 (G4470A; Agilent technologies, Santa Clara, CA, USA).
Project description:Treatment of cancer cells with anti-cancer drugs often fails to achieve complete remission. Yet, such drug treatments may induce alteration in the tumor’s gene expression patterns, including those of Cancer/Testis Antigens (CTA). The degradation products of such antigens can be presented as HLA peptides on the surface of the tumor cells and be developed into anti-cancer immunotherapeutics. For example, the DNA methyl transferase inhibitor, 5-aza-2'-deoxycytidine (Decitabine) has limited anti-tumor efficacy, yet it induces the expression of many genes, including CTAs that are normally silenced in the healthy adult tissues. In this study, the presentation of many new HLA peptides derived from CTAs and induced by Decitabine was demonstrated in three human Glioblastoma cell lines. Such presentation of CTA-derived HLA peptides can be exploited for development of new treatment modalities, combining drug treatment with anti-CTA targeted immunotherapy. The Decitabine-induced HLA peptidomes include many CTAs that are not normally detected in healthy tissues or in cancer cells, unless treated with the drug. In addition, the study included large-scale analyses of the simultaneous effects of Decitabine on the transcriptomes, proteomes and HLA peptidomes of the human Glioblastoma cells. It demonstrates the poor correlations between these three levels of gene expression, both in their total levels and in their response to the drug.
Project description:The expression of CTAs is normally restricted to gametogenic tissue but is often reactivated in the tumorigenic setting. This tumorigenic reactivation is thought to be due to global demethylation events during tumorigenesis. To test this, we employed an affymetrix microarray in the hypermethylated colorectal carcinoma tumor-derived cell line, HCT116, following 5-aza-2'-deoxycytidine treatment. We used microarray analysis to uncover genes whose expression is modulated by DNA methylation in the colorectal carcinoma tumor derived cell line, HCT116. HCT116 cells were exposed to 5-aza-2'-deoxycytidine for 72 hours. Total RNA was isolated and hybridized on to Affymetrix microarrays.
Project description:To screen for epigenetically silenced miRNAs, wecarried out miRNA microarray analysis in three colorectal cancer (CRC) cell lines (HCT116, DLD-1 and RKO) treated with or without 5-aza-2'-deoxycytidine (aza). HCT116 and RKO cells were also treated with aza plus 4-phenylbutyric acid (PBA). In addition, we analyzed HCT116 cells in which the DNA methyltransferase genes DNMT1 and DNMT3B were genetically disrupted (double knockout; DKO cells), thereby abrogating DNA methylation. Expression of a majority of miRNAs was downregulated in all three CRC cell lines tested, as compared to normal colonic mucosa. DAC treatment upregulated expression of a large number of miRNAs in all three CRC cell lines, and combination treatment with DAC plus PBA induced even greater numbers of miRNAs in CRC cells. The most profound effect on the miRNA expression profile was induced by genetic disruption of DNMT1 and DNMT3B in HCT116 cells.
Project description:We used bs-ATLAS-seq to comprehensively map the genomic location and assess the DNA methylation status of human full-length LINE-1 elements (L1). The approach is focused on the youngest family (L1HS), but it also catches a significant fraction of L1PA2 to L1PA8 elements. This was performed in HCT116 cells treated by the DNA methyltransferase inhibitor 5-aza-2’-deoxycytidine (5-aza) or in mock-treated cells (DMSO).
Project description:Treatment of cancer cells with anti-cancer drugs often fails to achieve complete remission. Yet, such drug treatments may induce alteration in the tumor’s gene expression patterns, including those of Cancer/Testis Antigens (CTA). The degradation products of such antigens can be presented as HLA peptides on the surface of the tumor cells and be developed into anti-cancer immunotherapeutics. For example, the DNA methyl transferase inhibitor, 5-aza-2'-deoxycytidine (Decitabine) has limited anti-tumor efficacy, yet it induces the expression of many genes, including CTAs that are normally silenced in the healthy adult tissues. In this study, the presentation of many new HLA peptides derived from CTAs and induced by Decitabine was demonstrated in three human Glioblastoma cell lines. Such presentation of CTA-derived HLA peptides can be exploited for development of new treatment modalities, combining drug treatment with anti-CTA targeted immunotherapy. The Decitabine-induced HLA peptidomes include many CTAs that are not normally detected in healthy tissues or in cancer cells, unless treated with the drug. In addition, the study included large-scale analyses of the simultaneous effects of Decitabine on the transcriptomes, proteomes and HLA peptidomes of the human Glioblastoma cells. It demonstrates the poor correlations between these three levels of gene expression, both in their total levels and in their response to the drug.
Project description:Promoter methylation is able to induce downregulation of gene expression. 5-Aza-2'-deoxycytidine(Aza), methytransferase inhibitor, induce CpG demethylation. Here, 5-Aza-2'-deoxycytidine(Aza) is treated in a human breast cancer cell, MCF7, for detection of gene expression change.