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: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:DNA hypermethylated genes undergo silencing and show re-expression in response to 5-Aza-CdR treatment. Agilent arrays were used to determine the genes that get reactivated in response to the drug treatment. To determine expression levels of genes in SW480, HCT116 and RKO.
Project description:We used expression profiling of colorectal cancer and endometrial cancer cell lines treated with demethylating agents to search for epigenetically regulated miRNAs. The study included three MMR-deficient colorectal cancer cell lines (HCT116, HCT15, and RKO), two MMR-proficient colorectal cancer cell lines (SW480, and T84) and two MMR-deficient endometrial cancer cell lines (AN3CA and HEC59).
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.
Project description:By silencing of RALA, a downstream member of the RAS signal transduction pathway, we aimed to determine whether genes downstream of a mutated KRAS (codon 12 or 13) or a mutated BRAF can have significant functions in colorectal cancer carcinogenesis. RALA was silenced in three colorectal cancer cell lines (SW480, HCT116 and HT29). Effects were normalized to mock-transfected cells and the effects of scramble siRNA were excluded. SW480, HCT116 and HT29 cell lines were treated with the PI3K inhibitor LY294002 or DMSO.
Project description:Genome wide gene expression profiling of RKO cells with combination treatments of non-target siRNA or SRCAP siRNA and PBS or 1uM 5-Aza-CdR treatment. The sample treated with non target siRNA and PBS serves as control sample. Total RNA obtained from isolated RKO cells.
Project description:Genome wide gene expression profiling of RKO cells with combination treatments of non-target siRNA or SRCAP siRNA and PBS or 1uM 5-Aza-CdR treatment. The sample treated with non target siRNA and PBS serves as control sample.
Project description:Comparing gene expression after combination treatment of 5-Aza-CdR and vitamin C to 5-Aza-CdR treatment alone in HCT116, HL60 and SNU398 cells
Project description:Genome wide DNA methylation profiling of RKO cells with combination treatments of non-target siRNA or SRCAP siRNA and PBS or 1uM 5-Aza-CdR treatment. The Illumina Infinium 27k Human DNA methylation Beadchip v1.2 was used to obtain DNA methylation profiles across 27,578 CpGs in treated RKO cells. Samples included cells under 4 different treatments. The sample treated with non target siRNA and PBS serves as control sample.
