title: Up-regulated expression of low molecular weight protein tyrosine phosphatases in different human cancers.
abstract: Protein tyrosine phosphorylation, mediated by the balanced action of tyrosine kinases and phosphatases, contributes to the regulation of the growth, migration, and invasion of normal and malignant cells. Among tyrosine phosphatases, low molecular weight protein tyrosine phosphatases (LMW-PTP) have been recognized as a possible "positive factor" in tumour onset and progression. The aim of this work was to assess whether LMW-PTP are differentially expressed in normal and malignant tissues. Using real-time PCR analysis we evaluated the expression levels of total LMW-PTP mRNA in surgical samples of breast, colon and lung cancers (63, 60, and 58, respectively), and in their paired adjacent not affected tissues. Moreover, the same analysis was carried out on a group of neuroblastomas (25 cases). Significant correlations between LMW-PTP overexpression and the most common clinical-pathological features of cancers exist. In colon cancer and neuroblastoma increased total LMW-PTP mRNA expression correlates with unfavourable outcome. While LMW-PTP mRNA expression increases in tumour samples, the relative contribution of the different isoforms does not change. Our findings indicate that LMW-PTP can be considered an oncogene as it is overexpressed in different tumour types and suggests that LMW-PTP enhanced expression is generally prognostic for a more aggressive cancer.
authors.affiliation: Department of Biochemical Sciences of the University of Florence, viale Morgagni 50, 50134 Firenze, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Malentacchi
authors.forename: Riccardo
authors.initials: R
authors.lastname: Marzocchini
authors.forename: Stefania
authors.initials: S
authors.lastname: Gelmini
authors.forename: Claudio
authors.initials: C
authors.lastname: Orlando
authors.forename: Mario
authors.initials: M
authors.lastname: Serio
authors.forename: Giampietro
authors.initials: G
authors.lastname: Ramponi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Raugei
mesh_terms: D017398:Alternative Splicing; D001943:Breast Neoplasms / Q000201:enzymology; D003110:Colonic Neoplasms / Q000201:enzymology; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D006801:Humans; D008175:Lung Neoplasms / Q000201:enzymology; D009369:Neoplasms / Q000201:enzymology*; D009447:Neuroblastoma / Q000201:enzymology; D016133:Polymerase Chain Reaction; D017027:Protein Tyrosine Phosphatases / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D012189:Retrospective Studies; D016019:Survival Analysis; D015854:Up-Regulation
chemical_list: D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; C490429:ACP1 protein, human; D017027:Protein Tyrosine Phosphatases