title: Ubenimex inhibits cell proliferation, migration and invasion in renal cell carcinoma: the effect is autophagy-associated.
abstract: Ubenimex is a low-molecular-weight dipeptide with the ability to inhibit aminopeptidase N (APN) activity, enhance the function of immunocompetent cells and confer antitumor effects. We sought to characterize the effects of ubenimex on renal cell carcinoma (RCC). The 786-O and OS-RC-2 human RCC cell lines were positive for APN expression and ubenimex decreased APN activity without affecting the expression. Ubenimex suppressed the proliferation of both cell lines in a concentration‑dependent manner, as assessed by curve growth analysis and WST-8 proliferation assay. Wound healing and Matrigel invasion assays demonstrated that the migration and invasion of the RCC cells were also markedly suppressed by ubenimex. Furthermore, ubenimex increased the mortality of both RCC cell lines as determined by the LDH cytotoxicity assay. This affect was accompanied by increased levels of LC3B with no apparent effect on Caspase3; and we observed that autophagy increased significantly after ubenimex treatment in both RCC cell lines by electron microscopy. Moreover, rapamycin enhanced the cytotoxic effect of ubenimex, while 3-methyladenine reversed the effect, indicating that ubenimex cytotoxicity occured through an autophagy-related mechanism. To further assess the potential applicability of ubenimex in the treatment of RCC, we performed immunohistochemistry using tissue microarrays representing 76 RCC patients that underwent radical nephrectomy. The results showed that APN was expressed in most, but not all of the RCC tissues and that the expression was reduced in RCC as compared to the normal kidney tissues, suggesting a potential role for APN in RCC development. Collectively, these results indicated that ubenimex inhibits proliferation, migration and invasion of RCC cells. Ubenimex may induce autophagy, which may be associated with its effect on the growth arrest and the cell death of RCC cells.
authors.affiliation: Department of Urology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, P.R. China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Urology, Weihai Municipal Hospital, Weihai, Shandong 264200, P.R. China.
authors.forename: Fang
authors.initials: F
authors.lastname: Xie
authors.affiliation: Department of Urology, QiHe People's Hospital, Dezhou, Shandong 251100, P.R. China.
authors.forename: Hafeng
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Urology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, P.R. China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Urology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, P.R. China.
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Urology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, P.R. China.
authors.forename: Liang
authors.initials: L
authors.lastname: Sun
authors.affiliation: Department of Urology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan 250021, P.R. China.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Niu
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000626:Aminopeptidases / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000378:metabolism; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D001343:Autophagy / Q000187:drug effects*; D002292:Carcinoma, Renal Cell / Q000188:drug therapy* / Q000473:pathology; D053148:Caspase 3 / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007680:Kidney Neoplasms / Q000188:drug therapy* / Q000473:pathology; D007930:Leucine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D020123:Sirolimus / Q000494:pharmacology; D014945:Wound Healing / Q000187:drug effects; D055815:Young Adult
chemical_list: D000903:Antibiotics, Antineoplastic; C025946:3-methyladenine; D000626:Aminopeptidases; D053148:Caspase 3; D007930:Leucine; C012211:ubenimex; D000225:Adenine; D020123:Sirolimus