ZXDA dependent transcription regulation in HCT116 human colon carcinoma cells upon doxycycline administration
Ontology highlight
ABSTRACT: The goal of the study was to investigate the effect of inducible ZXDA expression in HCT116 cell line. HCT116 clones expressing inducible versions of human ZXDA gene (2 clones wild-type; 2 clones ERP386-388AAA) were incubated with or without doxycycline.
Project description:Colorectal carcinoma cell line HCT116 cells were used as a model system to investigate the heterogeneity of different TP53 mutations. To this end, cells were haploidized by deleting an intronic splice site in one of the two wild-type TP53 alleles while the other copy was altered to different loss-of-function mutants via CRISPR/Cas9 gene editing. Cells expressing different haploid TP53 genotypes were treated with either Nutlin or DMSO to investigate the genetic variation between the mutants and the wild-type genotype.
Project description:We describe a synthetic interaction screen to identify genes preferentially required for proliferation of p53-deficient human cancer cells. An isogenic pair of p53+/+ and p53-/- human colorectal HCT116 cell lines was stably transduced with a short hairpin RNA (shRNA) library encoded by lentiviruses that integrate in the genomic DNA of the host. Comparison of the frequency of each type of integrated lentivirus in the 2 cell types at an early time point (40hrs) and after about 12 mitotic cycles (10days), reveals genes whose knockdown preferentially impaired growth of p53-/- or p53+/+ HCT116 cells. Keywords: Functional Genomics The region of the integrated lentiviruses is PCR amplified from genomic DNA of the two transduced cell populations at an early and a late time point.
Project description:The tumor suppressor protein p53 functions to regulate diverse cellular processes including apoptosis, cell cycle, senescence and metabolism. Act as a master transcription factor, it can transcriptionally regulate the gene expression of many downstream target genes. p53 is frequently mutated in cancer by single nucleotide/amino acid substitutions at the DNA binding domain that result in a mutant form of p53 protein and usually loses its DNA binding and transcriptional regulation abilities. In this study, we performed gene expression analysis using Affymetrix Exon Array ST1.0 platform to assess the transcriptome of wildtype p53 and 6 loss-of-function p53 mutants in p53null HCT116 cells. 8 samples were analyzed as a group. pcDNA3.1 empty construct was served as a control experiment.
Project description:Chromatin remodeling proteins are frequently dysregulated in human cancer, yet little is known about how they control tumorigenesis. Here, we uncover an epigenetic program mediated by the NAD+-dependent histone deacetylase Sirtuin 6 (SIRT6) that is critical for suppression of pancreatic ductal adenocarcinoma (PDAC), one of the most lethal malignancies. SIRT6 inactivation accelerates PDAC progression and metastasis via upregulation of Lin28b, a negative regulator of the let-7 microRNA. SIRT6 loss results in histone hyperacetylation at the Lin28b promoter, Myc recruitment, and pronounced induction of Lin28b and downstream let-7 target genes, HMGA2, IGF2BP1 and IGF2BP3. This epigenetic program defines a distinct subset representing 30-40% of human PDAC, characterized by poor prognosis and an exquisite dependence on Lin28b for tumor growth. Thus, we identify SIRT6 as an important PDAC tumor suppressor, and uncover the Lin28b pathway as a potential therapeutic target in a molecularlydefined PDAC subset. Small RNA-Seq experiments for PLKO and shLIN28B (three replicates each) in human Panc3.27 PDAC cells to identify miRNAs modulateed by LIN28B knockdown.
Project description:NFX1-91, a novel E6 cellular downstream target, functions as a transcriptional regulator and is involved in repressing hTERT expression. Other functions and downstream targets regulated by NFX1-91 were not well understood. We used microarrays to determine gene expression deregulated when NFX1-91 was knocked down. HCT116 cells was infected with lentivirus carrying NFX1-91 shRNA or control β-Galactosidase shRNA to stably knock down target gene expression. Total RNAs were extracted and hybridized on Affymetrix microarrays.
Project description:HCT116 and HCT116 p53 null were exposed to two Aurora kinase inhibitors (CYC116 and ZM447439) at cytotoxic concentrations. Within 4-5 weeks we were able to select and isolate 10 drug resistant clones from each group. 3 clones were selected for gene expression profiling using Affymetrix microarrays (Human Gene 1.0 ST Array). The samples in each group were initially given the code names as follows. Group 1. [R1.3, R4.2, R6.3: CYC116 p53 wild type], Group 2. [R8.7, R9.7, R10.7:CYC116 p53 null], Group 3. [R7.1, R15.1, R16.1:ZM447439 p53 wild type], and Group 4. [R1.5, R3.5, R4.5:ZM447439 p53 null). For publication purpose the names were later changed to, Group 1. [R1.1, R1.2, R1.3: CYC116 p53 wild type], Group 2. [R2.1, R2.2, R2.3:CYC116 p53 null], Group 3. [R3.1, R3.2, R3.3:ZM447439 p53 wild type], and Group 4. [R4.1, R4.2, R4.3:ZM447439 p53 null].
Project description:The presence of extra centrosomes is a feature of human tumours. However, it is unclear what are the changes elicited by the presence of these abnormalities. To determine the changes in gene expression induced by centrosome amplification, human mammary epithelial cells, MCF10A, expressing a doxycycline inducible PLK4 cDNA were used. Centrosome amplification was induced for 48 hrs upon the addition of doxycyclin to the culture medium. RNA was purified from MCF10A cells without extra centrosomes (no dox) and with extra centrosomes (dox) and processed for microarray analysis.
Project description:The goal of this experiment was to investigate the role of the FBXO38 ubiquitin ligase in the regulation of centromeric proteins deposition in HCT116 cell line.
Project description:The discovery of cytosine hydroxymethylation (5-hmC) as a mechanism that potentially controls DNA methylation changes typical of neoplasia prompted us to investigate its behavior in colon cancer. 5-hmC is globally reduced in proliferating cells such as colon tumors and the gut crypt progenitors, from which tumors can arise. Here, we show that colorectal tumors and cancer cells express Ten-Eleven Translocation (TET) transcripts at levels similar to normal tissues. Genome-wide analyses show that promoters marked by 5-hmC in normal tissue, and those identified as TET2 targets in colorectal cancer cells, are resistant to methylation gain in cancer. In vitro studies of TET2 in cancer cells confirm that these promoters are resistant to methylation gain independently of sustained TET2 expression. We also find that a considerable number of the methylation gain-resistant promoters marked by 5-hmC in normal colon overlap with those that are marked with poised bivalent histone modifications in embryonic stem cells. Together our results indicate that promoters that acquire 5-hmC upon normal colon differentiation are innately resistant to neoplastic hypermethylation by mechanisms that do not require high levels of 5-hmC in tumors. Our study highlights the potential of cytosine modifications as biomarkers of cancerous cell proliferation. Six samples were analyzed. 2 biological replicates each of HCT116 cells stably transfected with an empty vector control (TET_KD_Plk), with shRNA to TET2 (TET_KD_2C) and with shRNA to TET2 and TET3 (TET_KD_2.3)
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.