Project description:A patient-derived epithelium-only colon rectal organoid, also referred to as a colonoid, was generated from an adenoma (associated with a resection surgery of an invasive moderately differentiated colorectal adenocarcinoma) as part of the development of an on-going organoid biobank at the Michigan Medicine Translational Tissue Modeling Laboratory (TTML, www.UmichTTML.org). The genomic variant signature of this adenoma colonoid was characterized using whole exome sequencing in order to access genomic concordance between the source patient tissue (adenoma and histologically normal tissue 10 cm from lesion) and the in vitro culture, as well as to access genomic stability of the culture over time at 2 and 6.5 months in culture.
Project description:Colorectal cancer often develops slowly from adenoma. In this study, we aimed to identify the oncogenes involved in the progression of colorectal adenoma to carcinoma by Tandem Mass Tag (TMT)-based quantitative proteomics. Protein expression changes were compared by TMT-based quantitative mass spectrometry in seven paired samples of normal mucosa, adenoma and carcinoma. Moreover, a bioinformatics analysis of differential protein expression was performed to screen for oncogenes. Effects of oncogene knockdown on cell viability, proliferation, migration and invasion were analyzed in colorectal cancer cell lines. Effects of oncogene overexpression on cell viability and proliferation were analyzed in adenoma organoids. The protein UTP18 was consistently upregulated in the normal-adenoma-carcinoma sequence. UTP18 downregulation was shown to inhibit colorectal cancer cell viability, proliferation, migration and invasion. UTP18 overexpression promoted adenoma organoid viability and proliferation. UTP18 facilitated the expression of MYC and impaired expression of the tumor-suppressor p21. Our data revealed the importance of UTP18 as an effector in the progression of adenoma to carcinoma. Thus, UTP18 is implicated as a highly specific biomarker for early diagnosis of progressive adenomas.
Project description:We established human colorectal tumor organoids from benign adenoma, primary colorectal cancer or metastasized colorectal cancer. The gene signature of tumor organoids associated with their tumor progression status. We also generated genome-edited organoids from human intestinal organoids recapitulating adenoma-carcinoma sequence. Gene expression signature of the genome engineered organoids were similar to that of adenoma organoids. This result indicated multiple (up to five) genetic mutations were insufficient for gene expression reprogramming of colorectal cancer. We used microarrays to detail the global program of gene expression in human colorectal tumor organoids and artificially mutation introduced organoids.
Project description:The N-Myc Downstream-Regulated Gene 4 (NDRG4), a prominent biomarker for colorectal cancer (CRC), is specifically expressed by enteric neurons. Considering that nerves are important members of the tumor microenvironment, we here establish different Ndrg4 knockout (Ndrg4-/-) CRC models and an in-direct co-culture of primary enteric nervous system (ENS) cells and intestinal organoids to identify whether the ENS, via NDRG4, affects intestinal tumorigenesis. Linking immunostainings and gastrointestinal motility (GI) assays, we show that absence of Ndrg4 does not trigger any functional or morphological GI-abnormalities. However, combining in vivo, in vitro and quantitative proteomics data, we uncover that Ndrg4 knockdown is associated with enlarged intestinal adenoma development and that organoid growth is boosted by the Ndrg4-/- ENS cell secretome, which is enriched for Nidogen-1 (Nid1) and Fibulin-2 (Fbln2). Moreover, NID1 and FBLN2 are expressed in enteric neurons, enhance tumorigenic capacities of CRC cells and are enriched in human CRC secretomes. Hence, we provide evidence that the ENS, via loss of Ndrg4, is involved in colorectal pathogenesis and that ENS-derived Nidogen-1 and Fibulin-2 enhance colorectal carcinogenesis.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
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