title: Human breast cancer tissue expresses high level of type 1 5'-deiodinase.
abstract: Type 1 5'-deiodinase is one of two isoenzymes that participate in conversion of prohormone thyroxine into triiodothyronine (T3). A decrease in type 1 5'-deiodinase expression was observed in renal clear cell carcinoma, thyroid cancer, and lung cancer. The aim of this study was to evaluate type 1 5'-deiodinase activity and mRNA level in breast cancer tissue and non-cancerous surrounding breast tissue. Material was collected from 36 patients undergoing radical mastectomy or local tumor resection. In all non-cancerous breast tissues, type 1 50-deiodinase activity was found to be at a very low or immeasurable level, and type 1 5'-deiodinase mRNA was detected only in 2 out of the 36 samples. By contrast, 20 out of the 36 breast cancer tissues, mainly grades G1 and G2, expressed abundant type 1 5'-deiodinase activity and/or a high mRNA level. Our data demonstrated the presence of type 1 5'-deiodinase in well-differentiated breast cancer tissue. High enzymatic activity of type 1 50-deiodinase can potentially lead to an increase in the production of T3, which may affect target gene transcription, including genes responsible for energy expenditure, growth, differentiation, and proliferation.
authors.affiliation: Department of Internal Medicine and Endocrinology, Medical University of Warsaw, Banacha, Warsaw, Poland. debskim@wp.pl
authors.forename: Marcin Grzegorz
authors.initials: MG
authors.lastname: Debski
authors.forename: Janusz
authors.initials: J
authors.lastname: Pachucki
authors.forename: Michal
authors.initials: M
authors.lastname: Ambroziak
authors.forename: Wlodzimierz
authors.initials: W
authors.lastname: Olszewski
authors.forename: Ewa
authors.initials: E
authors.lastname: Bar-Andziak
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology*; D002454:Cell Differentiation; D004789:Enzyme Activation; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007453:Iodide Peroxidase / Q000235:genetics* / Q000378:metabolism; D008875:Middle Aged; D009367:Neoplasm Staging; D012333:RNA, Messenger / Q000378:metabolism; D013961:Thyroid Gland / Q000201:enzymology; D014284:Triiodothyronine / Q000096:biosynthesis
chemical_list: D012333:RNA, Messenger; D014284:Triiodothyronine; C109812:iodothyronine deiodinase type I; D007453:Iodide Peroxidase