Human breast cancer tissue expresses high level of type 1 5'-deiodinase.
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.
Debski
Marcin Grzegorz
MG
Department of Internal Medicine and Endocrinology, Medical University of Warsaw, Banacha, Warsaw, Poland. debskim@wp.pl
Pachucki
Janusz
J
Ambroziak
Michal
M
Olszewski
Wlodzimierz
W
Bar-Andziak
Ewa
E
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
D012333:RNA, Messenger; D014284:Triiodothyronine; C109812:iodothyronine deiodinase type I; D007453:Iodide Peroxidase