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Series GSE218480 Query DataSets for GSE218480
Status Public on Dec 12, 2023
Title TISSUE-LOCATION SPECIFIC TRANSCRIPTIONAL PROGRAMS IN COLON DETERMINE MOLECULAR DEPENDENCIES FOR TUMOR INITIATION [RNA-Seq]
Organism Mus musculus
Experiment type Expression profiling by high throughput sequencing
Summary It is not known why cancers arising in anatomically distinct locations but within the same tissue type can exhibit stark differences in molecular, pathological and clinical features. Cancers arising in proximal and distal sites of the colon are emblematic of these above differences as the proximal and distal colon cancers harbor differences in key molecular features, with BRAFV600E oncogene predominantly occurring in proximal colon cancers in the context of the increased promoter DNA methylation phenotype (CIMP-high), while distal colon cancers lack these molecular features. We determined the molecular basis of tissue-location specificity of driver mutations using normal mouse derived organoid models for colon cancer initiation. We show that the homeobox transcription factor, Cdx2, which is downregulated by DNA methylation in proximal colon cancers, plays distinct roles in regulating stem cell and differentiation in proximal compared to distal colon stem cells. Loss of Cdx2 altered the differentiation and stem cell programs and result in transformation by BRAFV600E specifically in the proximal but not distal colon stem cells. Analyses of RNA expression and Cdx2-binding to target genomic regions revealed that Cdx2 was a key effector of the transcriptional response to differentiation cues in proximal colon cells. This proximal colon-specific transcriptional program concurrently is tumor suppressive, and its loss sufficiently creates permissive state for oncogenic-BRAF mutations. The transcriptional program associated with Cdx2 loss in mouse proximal organoids matches that of human proximal colon cancers with downregulated CDX2 expression due to epigenetic silencing. Our analyses reveal that developmental and lineage-restricted transcription factors maintain tissue-location specific transcriptional programs which create critical dependencies for tumor initiation.
 
Overall design Proximal and distal colon organoids were generated from 3 mice and cultured in WENR-plus medium for 4 months before collecting sample for ChIP-seq. We applied Chipmentation to identify Cdx2 bound genomic regions in the organoids, with minor adaptions(Schmidl et al., 2015). For WENR-plus group, organoids were cultured in WENR-plus medium, while for WENR-minus group, organoids were cultured in WENR-plus medium for 2 day first after plating in 150 μl of Matrigel, followed with 3 days treatment of WENR-minus medium. RNA was extracted subsequently.
 
Contributor(s) Yang L, Thursby S, Baylin SB, Easwaran H
Citation(s) 38360902
Submission date Nov 21, 2022
Last update date Feb 26, 2024
Contact name Lijing Yang
E-mail(s) yanglijing23@126.com
Phone 4103189456
Organization name Johns Hopkins university
Street address 3400 N. Charles St.
City Baltimore
State/province MD
ZIP/Postal code 21218
Country USA
 
Platforms (1)
GPL21103 Illumina HiSeq 4000 (Mus musculus)
Samples (16)
GSM6745980 proximal scramble-sgRNA WENR-plus biol rep 1
GSM6745981 proximal scramble-sgRNA WENR-minus biol rep 1
GSM6745982 proximal Cdx2-sgRNA WENR-plus biol rep 1
This SubSeries is part of SuperSeries:
GSE218482 TISSUE-LOCATION SPECIFIC TRANSCRIPTIONAL PROGRAMS IN COLON DETERMINE MOLECULAR DEPENDENCIES FOR TUMOR INITIATION
Relations
BioProject PRJNA903914

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Supplementary file Size Download File type/resource
GSE218480_RAW.tar 27.0 Mb (http)(custom) TAR (of CSV)
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Raw data are available in SRA
Processed data provided as supplementary file

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