Project description:Oncogenic KRAS mutations and inactivation of the APC tumour suppressor co-occur in colorectal cancer (CRC). Despite efforts to target mutant KRAS directly, most therapeutic approaches focus upon downstream pathways, albeit with limited efficacy. Moreover, mutant KRAS alters the basal metabolism of cancer cells, rendering them ‘addicted’ to glutamine supporting proliferation. We show that concomitant mutation of Apc and Kras in the mouse intestinal epithelium profoundly rewires metabolism, increasing glutamine consumption. Furthermore, SLC7A5, a glutamine antiporter, is critical for colorectal tumorigenesis in models of both early and late-stage metastatic disease. Mechanistically, SLC7A5 maintains intracellular amino-acid levels following KRAS activation through transcriptional and metabolic reprogramming. This supports the increased demand for bulk protein synthesis that underpins enhanced proliferation of KRAS-mutant cells. Moreover, targeting protein synthesis, via mTORC1 inhibition, cooperates with Slc7a5 deletion to abrogate growth of established KRAS-mutant tumours. Together, these data suggest SLC7A5 as an attractive target for therapy-resistant KRAS-mutant CRC.
Project description:Transcriptional Profiling of the Transition from Normal Intestine to Adenoma in the APC(Min/+) Mouse. Tissue was from male 91-days old APC(Min/+) mouse (an animal model for human colon cancer). RNA was purified using Trizol and labeled for hybridization to high density oligonucleotide Affymetrix MG_U74Av2 arrays, using manufacturer protocol. We measured the relative expression level of >12000 genes and ESTs. -----------------------------------------; Samples used in analysis:; * GSM12501: Normal intestine diet #1 sample C1_0112 Dnmt+/- Min/+; * GSM12502: Tumor diet #1 sample T1_0112 Dnmt+/- Min/+; * GSM12503: Normal intestine diet #1 sample C2_0112 Dnmt+/+ Min/+; * GSM12504: Tumor diet #1 sample T2_0112 Dnmt+/+ Min/+; * GSM12505: Normal intestine diet #2 sample C1_003 Dnmt+/- Min/+; * GSM12506: Tumor diet #2 sample T1_003 Dnmt+/- Min/+; * GSM12507: Normal intestine diet #2 sample C2_003 Dnmt+/+ Min/+; * GSM12508: Tumor diet #2 sample T2_003 Dnmt+/+ Min/+; * GSM12509: Normal intestine diet #3 sample C1_005 Dnmt+/- Min/+; * GSM12510: Tumor diet #3 sample T1_005 Dnmt+/- Min/+; * GSM12511: Normal intestine diet #3 sample C2_005 Dnmt+/+ Min/+; * GSM12512: Tumor diet #3 sample T2_005 Dnmt+/+ Min/+; - - - - - - - - - - - - - - - - - - - - -; Comparisons were performed as described in Chen Z, Ge B, Hudson TJ and Rozen R. Gene Expression Patterns 1, 89-93, 2002. Comparing Normal intestine vs Adenoma. - - - - - - - - - - - - - - - - - - - - -; This resulted in the identification of differentially expressed transcripts. Identified transcripts were clustered based on functional information which was publicly available at time of analysis, obtained through the NetAffx WEB portal (www.Affymetrix.com) and literature.
Project description:To analyse roles of HAI-1/Spint1 in intestinal tumorigenesis, we examined the effect of intestine-specific deletion of Spint1 gene on Apc(Min/+) mice. The loss of Hai-1/Spint1 significantly accelerated tumor formation in ApcMin/+ mice and shortened their survival periods. Mouse small intestine tumor tissue or background mucosa lacking macroscopically visible tumors were proceeded to RNA extraction and hybridization on microarrays (Affymetrix Mouse Genome 430 2.0 Array). Non-tumor or tumor intestinal mucosa tissues of Apc (Min/+)/Spint1 (flox/flox) mice and non-tumor or tumor intestinal mucosa tissues of Apc (Min/+)/Spint1 (flox/flox)/Vil-Cre mice were analysed. The experiment was repeated respectively.
Project description:Nearly all colorectal cancers have dysregulated Wnt signalling, predominantly through the mutation of the Apc (Adenomatous Polyposis Coli) gene. Therefore it is of vital importance to elucidate the key Wnt target genes in intestinal cells in vivo. We have used a novel inducible cre-lox based murine system (designated ApcFlox) to investigate the consequences of perturbation of Wnt signalling following inactivation of Apc in vivo within 100% of the intestinal epithelium. We have employed microarray analysis at 3 time points within our ApcFlox system (Day 3 prior to the onset of phenotype, day 4 the establishment of the phenotype and day 5 gross phenotype of altered proliferation, differentiation and migration) and from adenomas arising in the ApcMin/+ background allowing us characterise Wnt/beta-catenin target genes based on their expression profiles during different stages of intestinal tumourigenesis. Furthermore, we have employed microarray analysis using livers from our ApcFlox system and have demonstrated that there is very little overlap in the Wnt target genes induced by Apc loss in the liver and the intestine. More importantly, we have been able to determine a novel set of putative Wnt/beta-catenin target genes which are upregulated at both early and late stages of tumourigenesis in the intestine and may represent novel therapeutic targets in colon cancer. Samples were collected from Genetcially modified mice of the genotypes indicated on the sample records. Where appropriate, gene recombination was induced using IP administration of beta-napthoflavone. Cohorts of samples were used to compare the affects of APC loss in the small intestine at three time points (and compared to matched control samples in which the gene was not recombined). Furthermore, these samples were compared to colonic polyps (and normal colon) taken from the Apcmin Mouse.
Project description:To analyse roles of HAI-1/Spint1 in intestinal tumorigenesis, we examined the effect of intestine-specific deletion of Spint1 gene on Apc(Min/+) mice. The loss of Hai-1/Spint1 significantly accelerated tumor formation in ApcMin/+ mice and shortened their survival periods. Mouse small intestine tumor tissue or background mucosa lacking macroscopically visible tumors were proceeded to RNA extraction and hybridization on microarrays (Affymetrix Mouse Genome 430 2.0 Array).
Project description:Purified CD11b+, Alveolar macrophage and HDM induced inflammatory DCs from WT and mTOR{delta} APC mice were profiled by RNA-seq to understand mTOR-dependent gene expression
Project description:APC mutant mice develop polys in the intestine, but not carcinoma. We found that additional deletion of Olfm4 gene induced carcinoma formation in the distal colon. To explore the molecular mechanism, we performed cDNA microarray to understand the gene expression files in the tumor tissues compared with WT, APC mutant and Olfm4 mutant mice.
Project description:We used single cell RNA sequencing (scRNA-seq) to analyze the diversity of cells within the murine small intestine in the absence of functional Apc.