title: Differentially expressed genes and estrogen receptor status in breast cancer.
abstract: There is a large and increasing body of experimental and clinical data supporting the involvement of estrogen on the proliferation of hormone-dependent breast tumors. Estrogen acts via its receptor (ER) stimulating cellular proliferation. ER and progesterone receptor (PR), which is regulated by estrogen via ER, have been used as prognostic markers in the clinical management of breast cancer patients. The aim of the present study was the identification of tumor-associated genes differentially expressed in breast tumors regarding the presence or absence of ER and PR. Using the technique of differential display reverse transcriptase-polymerase chain reaction (DDRT-PCR) we have isolated and cloned 127 cDNA fragments that showed differential expression in either ER+/PR+ or ER-/PR- breast tumors. Sequencing analysis of these clones revealed that 119 cDNAs had homology with known sequences in the National Center of Biotechnology Information (NCBI) and 8 were novel, showing no homology to known genes. Among these differentially expressed transcripts are metabolic enzymes, ribosomal proteins, transcription factors, hypothetical proteins, cell cycle regulators, cytoskelectum related genes, cell adhesion and motility genes. Differences in gene expression profiles are likely to explain the phenotypic differences between hormone-responsive and hormone-unresponsive breast tumors.
authors.affiliation: Departamento de Radiologia, Disciplina de Oncologia da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil. nagai@usp.br
authors.forename: Maria Aparecida
authors.initials: MA
authors.lastname: Nagai
authors.forename: Nancy
authors.initials: N
authors.lastname: Ros
authors.forename: Simone Aparecida
authors.initials: SA
authors.lastname: Bessa
authors.forename: Mário
authors.initials: M
authors.lastname: Mourão Neto
authors.forename: Elisabete Cristina
authors.initials: EC
authors.lastname: Miracca
authors.forename: Maria Mitzi
authors.initials: MM
authors.lastname: Brentani
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D002455:Cell Division; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D019992:Databases as Topic; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D010641:Phenotype; D011379:Prognosis; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011960:Receptors, Estrogen / Q000096:biosynthesis*; D011980:Receptors, Progesterone / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D012313:RNA