title: Beta catenin is associated with breast cancer progression in vitro.
abstract: Cancer is induced by a series of genetic alterations that lead to changes in the normal mechanisms controlling cell proliferation, differentiation, cell death, or genomic instability. The MCF-10F, a spontaneously immortalized human breast epithelial cell line, treated with benzo(a)pyrene and then transfected with the c-Ha-ras oncogene was used in these studies. The aim was to define the phenotypic alterations associated with the carcinogenic process. Carcinogen-treated and c-Ha-ras-transfected cells showed a progression of changes in the morphology as seen by transmission electron microscopy, anchorage-independent growth, invasiveness and capability of tumor formation in the SCID mice, as well as altered oncoprotein expression. Furthermore, these cells showed an increased expression of MDM2, Int-2 (FGF-3) and beta catenin in comparison to control MCF-10F as determined by fluorescence staining coupled with confocal microscopy. The MDM2, Int-2 (FGF-3) expressions were increased in cell lines transfected with the c-Ha-ras with or without carcinogen treatment as well as the tumor cell line derived from a tumor formed in the SCID mice in comparison to control cell line MCF-10F. However, beta catenin was only increased in the most aggressive tumorigenic cell lines in comparison with MCF-10F cell line and non-transfected ones. It can be concluded that malignant progression is a stepwise process and tumor growth occurs after a series of molecular events that parallel morphological changes indicative of cell transformation.
authors.affiliation: Department of Biology and Health, Faculty of Science, Tarapaca University, Arica, Chile. gmc24@columbia.edu
authors.forename: Gloria M
authors.initials: GM
authors.lastname: Calaf
authors.forename: Maria E
authors.initials: ME
authors.lastname: Alvarado
authors.forename: Tom K
authors.initials: TK
authors.lastname: Hei
mesh_terms: D001564:Benzo(a)pyrene / Q000633:toxicity; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology*; D002471:Cell Transformation, Neoplastic; D003598:Cytoskeletal Proteins / Q000096:biosynthesis*; D018450:Disease Progression; D005260:Female; D011905:Genes, ras; D006801:Humans; D046529:Microscopy, Electron, Transmission; D015534:Trans-Activators / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured; D051176:beta Catenin
chemical_list: C495270:CTNNB1 protein, human; D003598:Cytoskeletal Proteins; D015534:Trans-Activators; D051176:beta Catenin; D001564:Benzo(a)pyrene