hes1-protein--human and Adenoma

There is increasing body of evidence to suggest that some colonic serrated polyps do not fit morphologically with any of the proposed categories for serrated polyps recommended by the World Health Organization. Most of these polyps have morphologic features of traditional serrated adenoma (TSA) admixed with areas resembling sessile serrated adenoma (SSA) or hyperplastic polyp (HP). Based on these findings it has been suggested that at least some TSAs may arise in association with precursor HP or SSA lesions, particularly those that develop in right colon. To further evaluate this hypothesis, 39 serrated polyps from right side of the colon (cecum, ascending, and transverse colon) with mixed features of TSA and SSA were evaluated by 2 immunostains previously shown to represent markers of SSA. One is Annexin A10 which shows upregulated expression in SSA and the other is Hes-1 which is shown to be down regulated in SSA. The expression patterns of these markers were evaluated in SSA and TSA components of hybrid polyps and compared with control groups (pure SSAs and TSAs of right colon). SSA component in hybrid polyps did not show any significant difference in staining pattern compared with that seen in TSA component of hybrid polyps or in pure TSA polyps. These findings further support the hypothesis that recognizes SSA as a precursor lesion for TSA in the right colon.

Topics: Adenoma; Adult; Aged; Aged, 80 and over; Annexins; Colonic Neoplasms; Colonic Polyps; Female; Humans; Immunohistochemistry; Male; Middle Aged; Neoplasm Proteins; Transcription Factor HES-1

The Wnt and Notch1 signaling pathways play major roles in intestinal development and tumorigenesis. Sub-cellular localization of β-catenin has been implicated in colorectal carcinogenesis. However, the β-catenin and Notch intracellular domain (NICD) interaction has to be addressed. Immunohistochemistries of β-catenin, NICD, and dual immunofluorescence of β-catenin and NICD were analyzed in colorectal tissues and HT29 cell line. Moreover, real-time PCR analysis of CyclinD1, Hes1 and MUC2 was done in HT29 cells upon N-[N-(3, 5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT) treatment. Dual staining emphasized the strong interaction of β-catenin and NICD in adenoma and adenocarcinoma than in normal tissues. Hes1 transcript levels were decreased 1.5- and 7.1-fold in 12.5 and 25 µM DAPT-treated HT29 cells. CyclinD1 transcript levels decreased 1.2- and 1.6-fold, and MUC2 transcript level increased 4.3- and 7.5-fold in 12.5 and 25 µM DAPT-treated HT29 cells. The results of this study showed that the sub-cellular localization of β-catenin converges with NICD inducing proliferation through the activation of CyclinD1 and Hes1. Moreover, the inhibition of Notch1 signaling by DAPT leads to the arrest of cell proliferation and induces apoptosis leading to the upregulation of MUC2, a secretory cell lineage marker.

Topics: Adenocarcinoma; Adenoma; Basic Helix-Loop-Helix Transcription Factors; beta Catenin; Cell Proliferation; Colonic Neoplasms; Colorectal Neoplasms; Cyclin D1; Dipeptides; Dose-Response Relationship, Drug; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; HT29 Cells; Humans; Mucin-2; Protein Structure, Tertiary; Receptor, Notch1; Reference Values; Signal Transduction; Transcription Factor HES-1

Adenomatous polyps are precursors to colorectal cancer (CRC), whereas hyperplastic polyps (HPPs) have low risk of progression to CRC. Mutations in KRAS are found in ∼40% of CRCs and large adenomas and a subset of HPPs. We investigated the reasons why HPPs with KRAS mutations lack malignant potential and compared the effects of Kras/KRAS activation with those of Apc/APC inactivation, which promotes adenoma formation.. We activated a KrasG12D mutant allele or inactivated Apc alleles in mouse colon epithelium and analyzed phenotypes and expression of selected genes and proteins. The mouse data were validated using samples of human HPPs and adenomas. Signaling pathways and factors contributing to Kras/KRAS-induced phenotypes were studied in intestinal epithelial cells.. Activation of Kras led to hyperplasia and serrated crypt architecture akin to that observed in human HPPs. We also observed loss of Paneth cells and increases in goblet cell numbers. Abnormalities in Kras-mediated differentiation and proliferation required mitogen-activated protein kinase signaling and were linked to activation of the Hes1 transcription factor. Human HPPs also had activation of HES1. In contrast to Apc/APC inactivation, Kras/KRAS activation did not increase expression of crypt stem cell markers in colon epithelium or colony formation in vitro. Kras/KRAS activation was not associated with substantial induction of p16(INK4a) protein expression in mouse colon epithelium or human HPPs.. Although Kras/KRAS mutation promotes serrated and hyperplastic morphologic features in colon epithelium, it is not able to initiate adenoma development, perhaps in part because activated Kras/KRAS signaling does not increase the number of presumptive stem cells in affected crypts.

Topics: Adenoma; Animals; Basic Helix-Loop-Helix Transcription Factors; Cell Differentiation; Cell Line; Cell Proliferation; Colon; Colonic Polyps; Colorectal Neoplasms; Disease Models, Animal; Disease Progression; Homeodomain Proteins; Humans; Hyperplasia; Intestinal Mucosa; Mice; Mice, Transgenic; Mutation; Proto-Oncogene Proteins p21(ras); Signal Transduction; Stem Cells; Transcription Factor HES-1

Elements of the Notch pathway regulate differentiation; we investigated the expression of such elements in epithelial ovarian tumours. A total of 32 ovarian tumour samples (17 adenocarcinomas, three borderline tumours, 12 adenomas), two human ovarian cancer (A2780, OVCAR3), and one ovarian surface (IOSE 144) cell lines were analysed. The expression of Notch pathway elements was assessed by RT-PCR, real-time PCR (Notch 1), and by immunoblots (Notch 1 extracellular domain (EC), HES1). The proliferation and colony formation of A2780 cells were measured after stable transfection with activated Notch 1 (intracellular domain). Jagged 2, Delta-like-1, Manic Fringe, and TSL1 were expressed more frequently in adenocarcinomas whereas Deltex, Mastermind, and Radical Fringe were more frequent in adenomas. Quantitative PCR revealed decreased Notch 1 mRNA in ovarian adenocarcinomas compared with adenomas. The expression of Notch 1-EC protein was similar in benign and malignant tumours. HES1 protein was strongly expressed in 18/19 ovarian cancers and borderline tumours but not in adenomas. Transfecting A2780 cells with active Notch 1-IC resulted in a proliferative and colony formation advantage compared to mock transfected cells. Thus, Notch pathway elements are expressed in ovarian epithelial tumours and some of them are differentially expressed between adenomas and carcinomas. The Notch pathway could be a target for the development of therapies for ovarian cancer.

Topics: Adenocarcinoma; Adenoma; Adult; Aged; Aged, 80 and over; Basic Helix-Loop-Helix Transcription Factors; Cell Proliferation; Female; Homeodomain Proteins; Humans; Membrane Proteins; Middle Aged; Neoplasms, Glandular and Epithelial; Ovarian Neoplasms; Ovary; Receptors, Notch; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Transcription Factor HES-1; Tumor Cells, Cultured