Altered Notch signaling resulting from expression of a WAMTP1-MAML2 gene fusion in mucoepidermoid carcinomas and benign Warthin's tumors.

• Chromosome translocations in neoplasia commonly result in fusion genes that may encode either novel fusion proteins or normal, but ectopically expressed proteins. Here we report the cloning of a novel fusion gene in a common type of salivary and bronchial gland tumor, mucoepidermoid carcinomas (MEC), as well as in benign Warthin's tumors (WATs). The fusion, which results from a t(11;19)(q21-22;p13) translocation, creates a chimeric gene in which exon 1 of a novel gene of unknown function, designated WAMTP1, is linked to exons 2-5 of the recently identified Mastermind-like Notch coactivator MAML2. In the fusion protein, the N-terminal basic domain of MAML2, which is required for binding to intracellular Notch (Notch ICD), is replaced by an unrelated N-terminal sequence from WAMTP1. Mutation analysis of the N-terminus of WAMTP1-MAML2 identified two regions of importance for nuclear localization (amino acids 11-20) and for colocalization with MAML2 and Notch1 ICD in nuclear granules (amino acids 21-42). Analyses of the Notch target genes HES5 and MASH1 in MEC tumors with and without the WAMTP1-MAML2 fusion revealed upregulation of HES5 and downregulation of MASH1 in fusion positive MECs compared to normal salivary gland tissue and MECs lacking the fusion. These findings suggest that altered Notch signaling plays an important role in the genesis of benign and malignant neoplasms of salivary and bronchial gland origin.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

Nyckelord

Adenolymphoma

metabolism

Animals

Artificial Gene Fusion

COS Cells

Carcinoma

Mucoepidermoid

genetics

metabolism

Cell Line

Tumor

Cercopithecus aethiops

Chromosome Mapping

Chromosomes

Human

Pair 11

Chromosomes

Human

Pair 19

Cloning

Molecular

Exons

Gene Deletion

Gene Expression Regulation

Neoplastic

Green Fluorescent Proteins

Humans

Karyotyping

Luminescent Proteins

metabolism

Membrane Proteins

metabolism

Receptors

Notch

Salivary Gland Neoplasms

genetics

metabolism

Signal Transduction

Translocation

Genetic

Mucoepidermoid carcinoma

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)