alexa The PI3K Akt inhibitor LY294002 reverses BCRP-mediated drug resistance without affecting BCRP translocation.
Pharmaceutical Sciences

Pharmaceutical Sciences

Journal of Developing Drugs

Author(s): Imai Y, Yoshimori M, Fukuda K, Yamagishi H, Ueda Y

Abstract Share this page

Abstract Cellular responses toward cytotoxic drugs are influenced by crosstalk between oncogenic signals and resistance mechanisms. Inhibition of the PI3K/Akt pathway is effective in sensitizing cancer cells of various organs, although the mechanisms largely remain to be elucidated. Breast cancer resistance protein (BCRP)/ABCG2, a drug efflux pump, confers resistance to multiple anticancer agents such as SN-38 and topotecan. Previous studies reported that inhibition of the PI3K/Akt pathway, by gene knockout or PI3K inhibitors, modulated BCRP-mediated drug transport via BCRP translocation in hematopoietic stem cells, renal polarized cells and glioma stem-like cells of mammals. In this study, we assessed the effects of PI3K inhibitors, LY294002 and wortmannin, on BCRP-mediated anticancer drug resistance of human cancer MCF-7 and A431 cells. LY294002, but not wortmannin, reversed the BCRP-mediated SN-38 and topotecan resistance. LY294002 treatment did not affect total or cell surface BCRP levels as determined by western blotting and flow cytometry but blocked BCRP-mediated topotecan efflux in a dose-dependent manner. Immunohistochemical analyses also demonstrated unchanged cellular BCRP distribution. BCRP overexpression in MCF-7 and A431 cells did not confer LY294002 resistance, suggesting that LY294002 is not a transported substrate of BCRP. LY294002 is a derivative of quercetin, a member of flavonoids. Taken together, these results suggest that LY294002 inhibits BCRP-mediated drug transport not by BCRP translocation through the PI3K/Akt signal but putatively as a competitive inhibitor in a major subset of cancer cells. Due to its dual effects, LY294002 could be a lead compound for developing more effective and tolerable reagents for cancer treatment. This article was published in Oncol Rep and referenced in Journal of Developing Drugs

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords