Guvenc Tuna Bilge, Cleary Margot P, Demirel Pinar B, Dogan Soner
Biophysics, Yeditepe University Faculty of Medicine, İstanbul, TUR.
Food Science and Nutrition, University of Minnesota Hormel Institute, Austin, USA.
Cureus. 2020 Jan 22;12(1):e6737. doi: 10.7759/cureus.6737.
Leptin, an adipocytokine, is secreted from various tissues including the liver. The roles of both leptin and leptin receptor (ObR) in numerous pathophysiological conditions including mammary tumor (MT) development have been reported. However, the roles of leptin signaling-related proteins in the liver have not been reported previously in MT development. The objective of this study was to examine the expression levels of leptin and ObR in liver tissue of a transgenic breast cancer mouse model to investigate whether the roles of leptin in MT development are systemic or local. MMTV-TGF-α transgenic female mice were fed ad-libitum from week 10 up to week 74. Protein expression levels of leptin and ObR were measured in liver tissues of 74-week-old MMTV-TGF-α mice with and without MT by western blot. Serum leptin and insulin levels were measured using a enzyme-linked immunosorbent assay. Protein expression levels of leptin and ObR were similar in mice with MT compared to the ones without MT. Serum leptin and insulin levels were also not significantly different between the two groups. These results indicate that the effects of leptin signaling in MT development might be important at a local tissue level, such as mammary fat pad, and not as important at a systemic level.
瘦素是一种脂肪细胞因子，由包括肝脏在内的多种组织分泌。瘦素和瘦素受体（ObR）在包括乳腺肿瘤（MT）发展在内的众多病理生理状况中的作用已有报道。然而，瘦素信号相关蛋白在肝脏中在MT发展方面的作用此前尚未见报道。本研究的目的是检测转基因乳腺癌小鼠模型肝脏组织中瘦素和ObR的表达水平，以研究瘦素在MT发展中的作用是全身性的还是局部性的。MMTV-TGF-α转基因雌性小鼠从第10周开始自由进食直至第74周。通过蛋白质印迹法检测74周龄有或无MT的MMTV-TGF-α小鼠肝脏组织中瘦素和ObR的蛋白质表达水平。使用酶联免疫吸附测定法检测血清瘦素和胰岛素水平。与无MT的小鼠相比，有MT的小鼠中瘦素和ObR的蛋白质表达水平相似。两组之间血清瘦素和胰岛素水平也无显著差异。这些结果表明，瘦素信号在MT发展中的作用可能在局部组织水平（如乳腺脂肪垫）很重要，而在全身水平则不那么重要。
