Leptin promotes human endometrial carcinoma cell proliferation by enhancing aromatase (P450arom) expression and estradiol formation.
OBJECTIVE
Leptin, a multifunctional peptide hormone encoded by the obese (ob) gene, plays an important role in modulating lipid metabolism and energy equilibrium. Leptin reportedly acts as a cell growth factor and enhances the proliferation of various tumors. We investigated the effect of leptin on aromatase (P450arom) expression and estradiol (E2) formation in a model of endometrial carcinoma.


METHODS
We established a co-culture model of endometrial fibroblasts and the Ishikawa endometrial carcinoma cell line. P450arom mRNA and protein expression were measured with RT-PCR and immunoblotting, respectively, before and after leptin treatment. The effect of leptin on estradiol formation in endometrial carcinoma cells was also detected with a radioimmunological method.


RESULTS
P450arom mRNA expression was increased in co-cultures treated with 100 ng/ml leptin (P<0.01). Estradiol synthesis was induced when androstenedione was added to the culture medium, and significantly higher estradiol concentration was observed in co-cultures treated with 100 ng/ml leptin,


CONCLUSIONS
Leptin is an important component of the microenvironment and stimulates endometrial carcinoma cell proliferation via enhancing P450arom expression and estradiol synthesis.
Department of Obstetrics and Gynecology, First Affiliated Hospital, Liaoning Medical College, Jinzhou, Liaoning, China. Electronic address: clearsky315@yahoo.com.cn.
Lili
L
Liu
Lijun
L
Wang
Jindan
J
Zheng
Gang
G
Tang
D001141:Aromatase / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D002277:Carcinoma / Q000201:enzymology* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D018920:Coculture Techniques; D016889:Endometrial Neoplasms / Q000201:enzymology* / Q000473:pathology; D004958:Estradiol / Q000096:biosynthesis*; D005260:Female; D005347:Fibroblasts / Q000201:enzymology / Q000473:pathology; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D020738:Leptin / Q000502:physiology*
D020738:Leptin; D004958:Estradiol; D001141:Aromatase
Endometrial carcinoma; Leptin; Tumor microenvironment