Project description:Somatic mutations in APC or CTNNB1 genes lead to aberrant Wnt signaling and colorectal cancer (CRC) initiation and progression. Activation of Wnt pathway leads to the formation of beta-catenin-T-cell factor/Lymphoid enhancer binding factor 1 (Tcf/Lef1) complexes that activate transcription of oncogenic target genes. Lef1 is the only member of the Tcf gene family that is not expressed in the normal intestine, but is induced during intestinal tumorigenesis. Thus, we wanted to assess the role of Lef1 using genetic mouse models of intestinal adenomas and scRNA-seq technology. Tumorigenesis was initiated by inducing Apc mutation in Lgr5+ stem cells. Intestinal EpCAM+ epithelial cells of Lgr5-CreERT;Apc fl/fl (LApc) mouse and Lgr5-CreERT;Apc fl/fl; Lef1 fl/fl (LApcL) mouse were used to analyze the effects of Lef1 deletion in intestinal adenoma cells. We used WT mice as a control to distinguish adenoma cells.
Project description:To investigate the development of aldosterone-producing adenoma, we profiled cells of different areas of the adjacent adrenal cortex by snRNAseq to obtain possible trajectories towards adenoma formation.
Project description:Patients with germline APC mutations are recognized by hundreds of adenoma polyps in colon, which will give rise to adenocarcinoma inevitably. Over 700 germline APC mutations have been reported to be the leading cause of adenomatous polyposis. However, the underlying mechanism of APC mutation triggered colonic cancer remains mysterious. Here, using a modified STRT-seq protocol, we analyzed over 4000 single cells from the four matching adenomatous polyposis, adenocarcinoma, adjacent normal colon tissue and one lymphatic metastasis from four adenomatous polyposis patients with APC mutations. We identified the main cell types existed in human intestine such as B cells, mast cells, T cells, macrophage cells, endothelial cells, stromal cells and epithelial cells. And the proportional changes of various cell types during the development of adenoma were showed. The transcriptomic similarities and differences between adenoma, adenocarcinoma and adjacent normal tissue were comprehensively investigated. For better understanding the tumor progression process, we also take advantage of other genomic signatures, such as SNV and CNV. We found that the gene expression signatures of adenoma and adenocarcinoma were largely similar when compared with adjacent normal tissue. But the mutation accumulation was indeed observed during the progression from adenoma to adenocarcinoma. To summarized, our work will help us accurately investigate the pathogenic mechanism and heterogeneity of APC inactive mutation triggered colonic cancer, which will also help us better understand the non-familial colorectal cancers
Project description:Whole genomic microarray analysis was performed in order to identify gene expression profile alterations focusing on the dysplastic adenoma-carcinoma transition. Our aims were to determinate characteristic transcript sets for developing diagnostic mRNA expression patterns for objective classification of benign and malignant colorectal diseases and to test the classificatory power of these markers on an independent sample set. Total RNA was extracted from colonic biopsy samples of histologically negative patients and of patients with adenoma or colorectal cancer and were hybridized on Affymetrix HGU133 Plus 2.0 microarrays
Project description:Whole transcriptome expression levels of healthy colonic, colorectal adenoma and colorectal cancer biopsy samples were analyzed by HTA 2.0 microarrays
Project description:Comparison of Villin-Cre;Apc min;Lef1 fl/fl (VApcMinL) and ApcMin adenoma cells at the age of 11 wks. 2-3 male mice and 3-10 tumors per group were used in the experiment. Experiment was repeated twice (ApcMin2 and VApcMinL2 samples).
Project description:Leucine-rich repeats and immunoglobulin-like domains 1 (Lrig1) is a pan-ErbB negative regulator and intestinal stem cell marker downregulated in many malignancies. Over 91% Lrig1-CreERT2/CreERT2 (Lrig1-/-) mice developed duodenal adenomas, providing the first in vivo evidence Lrig1 acts as a tumor suppressor. We thus characterize the differential expressing transcripts in these duodenal adenomas to explore the pathegenesis. Elevated expression of the Egfr ligands was detected in adenomas compared to adjacent normal tissue. These adenomas also expressed the gastric-specific genes Gastrokine1 and Mucin5ac, indicating gastric metaplasia. In this dataset, we include the expression data obtained from proximal adenomas as well as adjacent normal tissue and wildtype proximal duodenum. These data are used to obtain 679 upregulated and 874 downregulated transcripts in tumors.
Project description:We wanted to assess the role of Lef1 in ex vivo organoids using genetic mouse models of intestinal adenomas and scRNA-seq technology. Tumorigenesis was initiated by inducing Apc mutation in Lgr5+ stem cells. Intestinal cells of Lgr5-CreERT;Apc fl/fl (LApc) mouse and Lgr5-CreERT;Apc fl/fl; Lef1 fl/fl (LApcL) mouse were used to generate adenoma organoids. Organoids were cultured without growth factors for three passages and dissociated with Tryple express. We used WT mice as a control to distinguish adenoma cells. WT organoids were cultured with growth factors.
Project description:Leucine-rich repeats and immunoglobulin-like domains 1 (Lrig1) is a pan-ErbB negative regulator and intestinal stem cell marker downregulated in many malignancies. Over 91% Lrig1-CreERT2/CreERT2 (Lrig1-/-) mice developed duodenal adenomas, providing the first in vivo evidence Lrig1 acts as a tumor suppressor. We thus characterize the differential expressing transcripts in these duodenal adenomas to explore the pathegenesis. Elevated expression of the Egfr ligands was detected in adenomas compared to adjacent normal tissue. These adenomas also expressed the gastric-specific genes Gastrokine1 and Mucin5ac, indicating gastric metaplasia. In this dataset, we include the expression data obtained from proximal adenomas as well as adjacent normal tissue and wildtype proximal duodenum. These data are used to obtain 679 upregulated and 874 downregulated transcripts in tumors. Total RNA from matched duodenal tumors or adjacent normal or wildtype duodenum was isolated with Rneasy (with Dnase digestion) and used to probe the Affymetrix Mouse Gene 1.0 ST chip; the probe was prepared with Ambion Expression Target preparation Kit P/N 4411974.
