This Article Full Text Full Text (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Touraine, P. Articles by Kelly, P. A. Search for Related Content PubMed PubMed Citation Articles by Touraine, P. Articles by Kelly, P. A.

Increased Expression of Prolactin Receptor Gene Assessed by Quantitative Polymerase Chain Reaction in Human Breast Tumors Versus Normal Breast Tissues

INSERM Unité 344, Faculté Medecine Necker (Ph.T., J-F.M., F.L., M-C.P.V., P.A.K.), 75730 Paris Cedex 15, France; Institut Curie (B.Z., A.N.), 75005 Paris, France; Clinique St. Jean de Dieu (J-C.D.), 75007 Paris, France; Département d’Endocrinologie, Hôpital Necker (C.M., F.K.), Paris, France; Laboratoire d’Explorations Hormonales, Hôpital Necker (C.T.), 75015 Paris, France

Address all correspondence and requests for reprints to: Philippe Touraine, INSERM Unité 344, Faculté Medecine Necker, 156 rue de Vaugirard, 75730 Paris Cedex 15, France.

The role of PRL in human breast tumorigenesis is not well understood. One of the limitations is the difficulty of accurately measuring PRL receptors (PRLR) in human tissues. We established a quantitative PCR method (Q-PCR) in T-47D human breast cancer cells and applied it to 29 patients, 25 of whom presented with either cancer or fibroadenoma. Four patients underwent a mammoplasty, and normal epithelial cells were cultured before Q-PCR. In T-47D cells, 31 x 10⁶ messenger RNA molecules were detected per microgram of total RNA. In all patients, expression of the PRLR gene was detected, varying from 1500 to 1 x 10⁶ molecules/µg of RNA in normal tissues and from 4500 to 34.7 x 10⁶ molecules/µg of RNA in tumors. PRLR expression was always greater in tumor than in normal contiguous tissue and similar in cultured mammary epithelial cells and normal breast tissues. Estradiol and progesterone receptor-negative tumors expressed low levels of PRLR transcripts, similar to normal breast tissue from menopausal women. Immunocytochemical analysis of PRLR confirmed stronger staining in almost all tumor samples compared with normal tissues. A messenger RNA encoding locally produced human PRL was also identified by RT-PCR in every sample tested. Our results confirm PRLR gene expression in all tissues studied, and moreover, indicate that this expression is increased in human breast tumors vs. normal contiguous tissues.