Roles of Adiponectin Signaling Related Proteins in Mammary Tumor Development

Objective: This study aims to investigate the expression levels of adiponectin signaling related proteins in mammary tissue, liver and breast cancer tissue in mice. Adiponectin, an adipocytokine, is secreted from adipose tissue and has been documented to have roles in diabetes, inflammation, and cancer development. In particular, levels of serum adiponectin are inversely associated with obesity and a decrease in serum adiponectin levels have been reported to be associated with breast cancer. There are two adiponectin receptor subtypes, AdipoR1 and AdipoR2, which have been identified in mammalian tissues, including human cancer cell lines and also in human mammary tumors. However, the role of adiponectin receptors in breast cancer development remains to be established. Methods: In this study, MMTV-TGF-α transgenic mice were fed from week 10 up to week 74 of age. Expression levels of adiponectin, AdipoR1 and AdipoR2 proteins were measured in the mammary fat pad (MFP), mammary tumor (MT) and liver tissues from 74 weeks old MMTV-TGF-α transgenic mice with and without MT using Western Blot. Adiponectin levels were measured using ELISA assay. Bulgular: Adiponektin ve AdipoR1 protein ekspresyon seviyeleri MT gelistiren farelerde, MT gelistirmeyen farelere gore anlamli olarak daha azdi. Fakat, MT-pozitif ve MT-negatif farelerin MT ve MFP dokularindaki AdipoR2 proteininin ekspresyon seviyeleri benzerdi. MT-pozitif ve MT-negatif farelerin karaciger dokusundaki adiponectin, AdipoR1 ve AdipoR2 protein ekspresyon seviyeleri de benzerdi. Ek olarak, MT-pozitif ve MT-negatif farelerin serum adiponectin seviyeleri benzerdi. Sonuc: Bu sonuclar adiponektin ve reseptorlerinin analiz edilen dokuya spesifik bagimli olarak duzenlendigini isaret etmektedir. Ayrica, AdipoR1 ve adiponectin MT gelisiminde onemli rol oynuyor olabilir.