LYP, a novel bestatin derivative, inhibits cell growth and suppresses APN/CD13 activity in human ovarian carcinoma cells more potently than bestatin.
LYP is a bestatin dimethylaminoethyl ester which inhibits aminopeptidase N (APN/CD13). Our goal in this study was to evaluate LYP as a candidate compound for cancer treatment, beginning by studying its inhibitory effects on tumors and then comparing it to bestatin. Experiments were performed on human ovarian carcinoma (OVCA) ES-2 and SKOV-3 cell lines, which have high and low levels of APN/CD13 respectively. LYP effectively inhibited ES-2 cell growth as estimated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and the trypan blue dye-exclusion test. LYP significantly suppressed APN/CD13 activity on the surface of ES-2 cells as measured by quantifying the enzymatic cleavage of the substrate L-leucine-p-nitroanilide. The inhibitory effects of LYP were greater than those of bestatin at the same concentrations. In contrast, LYP was a weak inhibitor of SKOV-3 cell growth, suggesting that LYP may inhibit ES-2 cell growth via suppression of APN/CD13. Inhibition of APN/CD13 expression was also demonstrated with immunofluorescent flow cytometry and Western blot analysis. Inhibitory effects of LYP were confirmed by using a mouse model in which LYP delayed the growth of ES-2 xenografts in mice after 2 weeks of LYP injections. Inhibition of APN/CD13 expression was demonstrated in the ES-2 xenografts using Western blot analysis. The inhibitory effects of LYP on the ES-2 xenografts were stronger than those of bestatin. These results suggest that LYP has a powerful inhibitory effect on the growth of OVCA cells and that the mechanism may be via a decrease in the expression of APN/CD13.
Gao
Jian-Jun
JJ
Department of Pharmacology, School of Pharmaceutical Sciences, Shandong University, Jinan, China.
Gao
Zu-Hua
ZH
Zhao
Cui-Rong
CR
Yuan
Yi
Y
Cui
Shu-Xiang
SX
Zhang
Xiao-Fan
XF
Cheng
Yan-Na
YN
Xu
Wen-Fang
WF
Tang
Wei
W
Qu
Xian-Jun
XJ
D000818:Animals; D018826:CD13 Antigens / Q000037:antagonists & inhibitors* / Q000378:metabolism; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D049109:Cell Proliferation / Q000187:drug effects; D004952:Esters; D005260:Female; D006801:Humans; D007930:Leucine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D051379:Mice; D010051:Ovarian Neoplasms / Q000097:blood / Q000201:enzymology* / Q000473:pathology*; D023041:Xenograft Model Antitumor Assays
D004952:Esters; C561026:LYP compound; D018826:CD13 Antigens; D007930:Leucine; C012211:ubenimex