Research article

P-LAP/IRAP-induced cell proliferation and glucose uptake in endometrial carcinoma cells via insulin receptor signaling

Kiyosumi Shibata , Hiroaki Kajiyama , Kazuhiko Ino , Akihiro Nawa , Seiji Nomura , Shigehiko Mizutani and Fumitaka Kikkawa

Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, Nagoya, Japan

author email corresponding author email

BMC Cancer 2007, 7:15doi:10.1186/1471-2407-7-15

Published:	19 January 2007

Abstract

Background

Hyperglycemia or hyperinsulinemia contributes to poorer endometrial cancer survival. It was shown that P-LAP/IRAP translocates to the plasma membrane in response to insulin stimulation. Recently, we demonstrated that P-LAP/IRAP is associated with a poor prognosis in endometrial adenocarcinoma patients. The aim of this study was to examine whether the malignant potential of endometrial cancer enhanced by P-LAP/IRAP is due to increased glucose uptake via the P-LAP/IRAP-mediated activation of insulin signaling.

Methods

We transfected P-LAP/IRAP cDNA into A-MEC cells (endometrial adenocarcinoma cell line), and A-MEC-LAP cells expressed a remarkably high level of GLUT4 proteins.

Results

³H-2-deoxyglucose uptake which responds to insulin in A-MEC-LAP cells was significantly higher than that of A-MEC-pc cells. A-MEC-LAP cells exhibited a significant growth-stimulatory effect compared to A-MEC-pc cells. A-MEC-LAP cells expressed a remarkably high level of p85PI3K protein compared to A-MEC-pc cells, and showed a higher degree of AKT phosphorylation by insulin stimulation.

Conclusion

In summary, P-LAP/IRAP was involved in the increasing malignant potential of endometrial cancer mediated by insulin. P-LAP/IRAP was suggested to be a potential new target of molecular-targeted therapy for endometrial cancer.