title: Thymosin beta-10 protein synthesis suppression reduces the growth of human thyroid carcinoma cells in semisolid medium.
abstract: Beta-thymosins are structurally related, highly conserved acidic polypeptides, originally isolated from calf thymus. We have recently shown that the TB10 gene is overexpressed in human thyroid carcinoma cell lines and tissues, particularly in undifferentiated thyroid carcinomas, but expressed at an undetectable level in normal thyroid cells. The precise role of thymosin beta-10 (TB10) activity in maintaining the malignant phenotype of thyroid cell lines is unknown. To investigate TB10 function and relevance in a model system we used an antisense methodology to suppress TB10 protein synthesis in two human thyroid carcinoma cell lines (NPA and ARO). The growth in soft agar of NPA and ARO cells carrying a TB10 construct in an antisense orientation was significantly reduced. Conversely, anchorage-dependent growth was unchanged in NPA and ARO cells carrying the TB10 construct in a sense orientation or carrying the backbone vector. TB10 expression also affected actin organization. In fact, stress fibers were long and thick in ARO cells in which TB10 expression was suppressed by the antisense construct. Conversely, they were scarce and short in the vector-transfected ARO cells. These data suggest that TB10 plays a critical role in the regulation of anchorage-independent growth and assembly of actin filaments.
authors.affiliation: Oncologia Sperimentale E, Istituto Nazionale dei Tumori di Napoli, Fondazione G. Pascale, Napoli, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Santelli
authors.forename: Paola Cannada
authors.initials: PC
authors.lastname: Bartoli
authors.forename: Ada
authors.initials: A
authors.lastname: Giuliano
authors.forename: Antonio
authors.initials: A
authors.lastname: Porcellini
authors.forename: Alba
authors.initials: A
authors.lastname: Mineo
authors.forename: Maria Vittoria
authors.initials: MV
authors.lastname: Barone
authors.forename: Immacolata
authors.initials: I
authors.lastname: Busiello
authors.forename: Francesco
authors.initials: F
authors.lastname: Trapasso
authors.forename: Daniela
authors.initials: D
authors.lastname: Califano
authors.forename: Alfredo
authors.initials: A
authors.lastname: Fusco
mesh_terms: D000362:Agar; D016375:Antisense Elements (Genetics) / Q000494:pharmacology; D002291:Carcinoma, Papillary; D002448:Cell Adhesion / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D003470:Culture Media / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D010641:Phenotype; D022502:Stress Fibers / Q000502:physiology; D013947:Thymosin / Q000235:genetics*; D013964:Thyroid Neoplasms; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D016375:Antisense Elements (Genetics); D003470:Culture Media; D013947:Thymosin; C039302:thymosin beta(10); D000362:Agar