title: Claudins upregulation in human colorectal cancer.
abstract: In colorectal cancer tight junction molecular and morphological alterations are poorly understood. In this study, adenocarcinoma tissues and their paired normal mucosa (n = 12) were analyzed for tight junction alterations molecular. The expression of claudin-1, -3 and -4 was upregulated 5.7-, 1.5- and 2.4-fold, respectively, in colorectal tumor tissues in comparison to the normal ones. Although tight junction remains in the cancerous epithelium, its barrier function was altered. Despite claudins overexpression, paracellular permeability to ruthenium red was increased and a significant disorganization of tight junction strands was observed in freeze fracture replicas. Whereas the functional significance of claudin overexpression in colorectal cancer is unclear, these proteins can become potential markers and targets in colorectal cancer.
authors.affiliation: Grupo de Biologia Estrutural, Divisão de Biologia Celular, Centro de Pesquisa, Instituto Nacional de Câncer, Rio de Janeiro, Brazil.
authors.forename: Silvia Souza
authors.initials: SS
authors.lastname: de Oliveira
authors.forename: Ivanir Martins
authors.initials: IM
authors.lastname: de Oliveira
authors.forename: Wanderley
authors.initials: W
authors.lastname: De Souza
authors.forename: José Andrés
authors.initials: JA
authors.lastname: Morgado-Díaz
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D015820:Cadherins / Q000378:metabolism; D062445:Claudin-1; D062465:Claudin-3; D062506:Claudin-4; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D008565:Membrane Proteins / Q000032:analysis / Q000378:metabolism*; D010539:Permeability; D012430:Ruthenium Red / Q000378:metabolism; D019108:Tight Junctions / Q000378:metabolism / Q000648:ultrastructure; D015854:Up-Regulation
chemical_list: C568108:CLDN1 protein, human; C568122:CLDN3 protein, human; C568157:CLDN4 protein, human; D015820:Cadherins; D062445:Claudin-1; D062465:Claudin-3; D062506:Claudin-4; D008565:Membrane Proteins; D012430:Ruthenium Red