title: Isolation and characterization of genes associated with the anti-tumor activity of glucocorticoids.
abstract: Treatment of ST1 rat glioma cells with glucocorticoid hormones leads to complete reversion of their transformed phenotype and loss of their tumorigenic potential. In order to study the molecular basis of the anti-tumor activity of these hormones, we isolated glucocorticoid-regulated cDNA sequences associated with ST1 cells' phenotypic reversion, using suppression subtractive hybridization (SSH). DNA sequencing of the subtracted cDNA pool, cloned into the pBluescript vector, revealed three widely expressed, well known negative growth regulators, namely, thrombospondin 1, cyclin G and tyrosine phosphatase CL100, as primary targets of glucocorticoid hormones. Additionally, a gene recently described in human brain, NRP/B (nuclear restricted protein in brain) that associates with p110Rb in induction of neuronal differentiation and a new truncated transcript of the tenascin-X gene family, are also shown to be up-regulated by glucocorticoids. The products of these genes are strong candidates to be important players in glucocorticoids anti-tumor activity.
authors.affiliation: Instituto de Qui;mica, Universidade de São Paulo, C.P. 26.077, 05513-970 SP, São Paulo, Brazil.
authors.forename: Cleber Giovane
authors.initials: CG
authors.lastname: Vedoy
authors.forename: Mari Cleide
authors.initials: MC
authors.lastname: Sogayar
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism / Q000494:pharmacology*; D015152:Blotting, Northern; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic; D005938:Glucocorticoids / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D006824:Hybridization, Genetic; D006854:Hydrocortisone / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010641:Phenotype; D051381:Rats; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D018076:DNA, Complementary; D005938:Glucocorticoids; D006854:Hydrocortisone