Aberrant expression and possible involvement of the leptin receptor in endometrial cancer.
OBJECTIVE
Leptin and its receptor are the key players in the regulation of energy balance and body weight control. However, their roles in gynecological malignancies are mostly unclear. In this study, we analyzed the expression and possible involvement of leptin and the leptin receptor in the pathogenesis of endometrial cancer.


METHODS
Radioimmunoassay was performed to analyze the serum leptin levels in the endometrial cancer patients, while RT-PCR, immunoblotting, and immunohistochemistry techniques were applied to study the expression of leptin receptor in the endometrioid-type endometrial cancer tissues. Furthermore, BrdU labeling followed by immunofluorescent analysis was used to analyze the effect of leptin receptor overexpression on endometrial cancer cell proliferation.


RESULTS
Serum leptin levels are elevated in endometrial cancer patients, but show no significant difference to those of normal controls when normalized by body mass index. On the other hand, lower expression levels of leptin receptor short form (Ob-Ra) were observed in most endometrial cancer tissues, especially in the poorly differentiated ones, and the forced expression of Ob-Ra in RL95-2 endometrial cancer cells prevented them from entering the S-phase.


CONCLUSIONS
In summary, our data demonstrates for the first time that the leptin receptor is aberrantly expressed in endometrial cancer tissues and is possibly involved in the pathogenesis of endometrial cancer.
Yuan
Shyng-Shiou F
SS
Department of Obstetrics and Gynecology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan, ROC. yuanssf@ms33.hinet.net
Tsai
Kun-Bow
KB
Chung
Yueh-Fang
YF
Chan
Te-Fu
TF
Yeh
Yao-Tsung
YT
Tsai
Li-Yu
LY
Su
Jinu-Huang
JH
D002455:Cell Division / Q000502:physiology; D016889:Endometrial Neoplasms / Q000097:blood / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D020738:Leptin / Q000096:biosynthesis / Q000097:blood; D008875:Middle Aged; D020033:Protein Isoforms / Q000096:biosynthesis; D011863:Radioimmunoassay; D011956:Receptors, Cell Surface / Q000096:biosynthesis* / Q000502:physiology; D054411:Receptors, Leptin; D016196:S Phase / Q000502:physiology
C515448:LEPR protein, human; D020738:Leptin; D020033:Protein Isoforms; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin