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. 5 normal colon samples and 4 matching tumor samples were profiled for 5-hydroxymethylcytosine content genomewide using hmeDIP-seq. The colorectal cancer cell line HCT116 was profiled for binding of TET2 genomewide by chromatin immunoprecipitation sequencing (ChIP-seq).
Project description:Bordel2018 - GSMM for Human Metabolic
Reactions (HMR database)
This model is described in the article:
Constraint based modeling of
metabolism allows finding metabolic cancer hallmarks and
identifying personalized therapeutic windows
Sergio Bordel
Oncotarget. 2018; 9:19716-19729
Abstract:
In order to choose optimal personalized anticancer
treatments, transcriptomic data should be analyzed within the
frame of biological networks. The best known human biological
network (in terms of the interactions between its different
components) is metabolism. Cancer cells have been known to have
specific metabolic features for a long time and currently there
is a growing interest in characterizing new cancer specific
metabolic hallmarks. In this article it is presented a method
to find personalized therapeutic windows using RNA-seq data and
Genome Scale Metabolic Models. This method is implemented in
the python library, pyTARG. Our predictions showed that the
most anticancer selective (affecting 27 out of 34 considered
cancer cell lines and only 1 out of 6 healthy mesenchymal stem
cell lines) single metabolic reactions are those involved in
cholesterol biosynthesis. Excluding cholesterol biosynthesis,
all the considered cell lines can be selectively affected by
targeting different combinations (from 1 to 5 reactions) of
only 18 metabolic reactions, which suggests that a small subset
of drugs or siRNAs combined in patient specific manners could
be at the core of metabolism based personalized treatments.
This model is hosted on
BioModels Database
and identified by:
MODEL1707250000.
To cite BioModels Database, please use:
Chelliah V et al. BioModels: ten-year
anniversary. Nucl. Acids Res. 2015, 43(Database
issue):D542-8.
To the extent possible under law, all copyright and related or
neighbouring rights to this encoded model have been dedicated to
the public domain worldwide. Please refer to
CC0
Public Domain Dedication for more information.
Project description:N6-methyl adenosine (m6A) is one of the most important RNA modifications involved in several biological and pathological processes, including cancer. Dysregulation of m6A has been linked with tumor initiation, progression, and metastasis of several cancer types, including colon cancer. A transcriptome of colon cancer describes the dysregulated coding and non-coding RNAs but does not reveal the mechanisms like m6A modifications that determine the post-transcriptional and pre-translational regulations. Epi-transcriptome profiling of m6A in colon cancer cell lines was performed using Methylated RNA Immunoprecipitation (MeRIP) sequencing. Overall, the study illustrates the distribution of m6A across the transcriptome of various colon cancer cell lines.
Project description:Prostate cancer is the most common cancer in men. We identified that miR-29 family is the most androgen-responsive miRNA in hormone-refractory prostate cancer cells. For the screening of miR-29b target, we performed microarray analysis in two prostate cancer cells. Because TET2 is the primary target of miR-29 family by our analysis, we also performed TET2 signaling by microarray. In order to investigate the downsteam signals mediated by TET2 and miR-29b, we performed comprehensive analysis of gene expression in positive prostate cancer cell lines after siTET2 or miR-29b treatment. Observation of gene expression changes after treatmet with siRNA targeting TET2 or miR-29b in prostate cancer cell lines with microarray.
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. messenger RNA levels were measured in total RNA extracted from primary colon tissues. Normal away are at least 20cm from tumors.
Project description:MicroRNAs (miRNAs) are intrinsic regulators in the various cellular processes, and their abnormalities are considered to be involved in the onset of human disorders, including cancer. Circulating miRNA is focused as new cancer biomarker however it is regarded that circulating RNA are released not only from tumor but also by various pathways. Recently, exosomes, small membrane vesicles, have been a major interest in cancer research field, because of their unique biological properties. Exosomes are secreted from various cells and the components (Lipids, mRNAs, miRNAs and proteins) reflect origin of the cells secreting them. Identification of exosomal miRNAs from cancer cells is expected to provide useful biomarkers of cancer. To identify specific exosomal miRNAs as candidate biomarkers for colorectal cancer, we compared exosomal miRNA profiles of 5 colon cancer cell lines with that of normal colon-derived epithelial cells, and isolated a subset of miRNAs as commonly-secreted miRNAs from colon cancer cells Endogenously expression of microRNAs were analyzed by Agilent Human miRNA V3 Microarray (G4470C) using total RNA of three human colon cancer cell lines (HT-29 cells, SW48 cells, and RKO cells) at two independent experiments. Exosomal microRNAs were analyzed by microRNA microarray using total RNA of exosomes from conditioned media of three human colon cancer cell lines, HT-29 cells, SW48 cells, and RKO cells at three independent experiments. Exosomes were prepared by step-wise ultra-centrifugation methods. RNA was prepared by Trizol or Trizol-LS reagent (Invitrogen) and RNeasy mini spin column (Qiagen).