Malignant transformation of mammary epithelial cells increases expression of leptin and leptin receptor.
Both normal and malignant mammary tissues have been shown to produce leptin and express leptin receptors. This study compared the expression of leptin and leptin receptor mRNA in a variety of normal and malignant mammary epithelial cell lines and observed that in general the malignant lines expressed higher levels of leptin and leptin receptor mRNA than nonmalignant lines. Furthermore, oncogenic transformation of nonmalignant cell lines increased expression of leptin and leptin receptor, with expression of ErbB2 giving particularly high levels of expression of long-form leptin receptor. In addition, nonmalignant cells exhibited little or no increase in DNA synthesis following leptin treatment, whereas oncogene-transformed cells had increased DNA synthesis in response to leptin. These effects varied among oncogenes, with ErbB2-transformed cells showing particularly high expression of leptin receptor mRNA and high response to leptin.
Sheffield
Lewis
L
Department of Dairy Science, University of Wisconsin, Madison, Wisconsin 53706, USA. lgsheffi@wisc.edu
D000818:Animals; D002460:Cell Line; D002461:Cell Line, Transformed; D002471:Cell Transformation, Neoplastic / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D020738:Leptin / Q000096:biosynthesis*; D008321:Mammary Glands, Animal / Q000378:metabolism*; D042361:Mammary Glands, Human / Q000378:metabolism*; D051379:Mice; D054411:Receptors, Leptin / Q000096:biosynthesis*
D020738:Leptin; D054411:Receptors, Leptin