Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Poly(ethylene glycol)–poly(lysine) block copolymer–ubenimex conjugate targets aminopeptidase N and exerts an antitumor effect in hepatocellular carcinoma stem cells

Abstract

Previous studies highlighted that aminopeptidase N (APN)/CD13 acts as a scavenger in the survival of hepatocellular carcinoma (HCC) stem cells by reducing reactive oxygen species (ROS) levels. Hence, it has been proposed that APN/CD13 inhibition can increase cellular ROS levels and sensitize cells to chemotherapeutic agents. Although ubenimex, also known as bestatin, competitively inhibits proteases such as APN/CD13 on the cellular membrane and it is clinically used for patients with acute myeloid leukemia and lymphedema, research has demonstrated that higher concentrations of the agent induce the death of APN/CD13+ HCC stem cells. In this study, we developed a poly(ethylene glycol)–poly(lysine) block copolymer–ubenimex conjugate (PEG-b-PLys(Ube)) to increase the efficacy of reagents in APN/CD13+ cancer stem cells. Exposure to PEG-b-PLys(Ube) increased the intracellular ROS concentration by inhibiting APN enzyme activity, permitting the induction of apoptosis and attenuation of HCC cell proliferation. In addition, PEG-b-PLys(Ube) exhibited a relatively stronger antitumor effect in mice than PEG-b-PLys alone or phosphate-buffered saline. Moreover, an isobologram analysis revealed that combinations of fluorouracil, cisplatin, or doxorubicin with PEG-b-PLys(Ube) exhibited synergistic effects. This study demonstrated that PEG-b-PLys(Ube) does not impair the properties of ubenimex and exerts a potent antitumor effect.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8

Similar content being viewed by others

References

  1. Colvin H, Mizushima T, Eguchi H, Takiguchi S, Doki Y, Mori M. Gastroenterological surgery in Japan: The past, the present and the future. Ann Gastroenterol Surg. 2017;1:5–10.

    Article  Google Scholar 

  2. Wada H, Eguchi H, Nagano H, Kubo S, Nakai T, Kaibori M, et al.Perioperative allogenic blood transfusion is a poor prognostic factor after hepatocellular carcinoma surgery: a multi-center analysis. Surg Today. 2017;48:73–9.

    Article  Google Scholar 

  3. Tomimaru Y, Wada H, Eguchi H, Tomokuni A, Hama N, Kawamoto K, et al. Clinical significance of surgical resection of metastatic lymph nodes from hepatocellular carcinoma. Surg Today. 2015;45:1112–20.

    Article  Google Scholar 

  4. Sun JH, Luo Q, Liu LL, Song GB. Liver cancer stem cell markers: progression and therapeutic implications. World J Gastroenterol. 2016;22:3547–57.

    Article  CAS  Google Scholar 

  5. Abou-Alfa GK. Hepatocellular carcinoma: molecular biology and therapy. Semin Oncol. 2006;33(6Suppl 11):S79–83.

    Article  CAS  Google Scholar 

  6. Vinogradov S, Wei X. Cancer stem cells and drug resistance: the potential of nanomedicine. Nanomed (Lond). 2012;7:597–615.

    Article  CAS  Google Scholar 

  7. Bao B, Ahmad A, Azmi AS, Ali S, Sarkar FH. Overview of cancer stem cells (CSCs) and mechanisms of their regulation: implications for cancer therapy. Curr Protoc Pharmacol. 2013;14:25. Chapter 14:Unit.

    PubMed  Google Scholar 

  8. Ji J, Wang XW. Clinical implications of cancer stem cell biology in hepatocellular carcinoma. Semin Oncol. 2012;39:461–72.

    Article  CAS  Google Scholar 

  9. Ishii H, Iwatsuki M, Ieta K, Ohta D, Haraguchi N, Mimori K, et al. Cancer stem cells and chemoradiation resistance. Cancer Sci. 2008;99:1871–7.

    Article  CAS  Google Scholar 

  10. Hu YFL. Targeting cancer stem cells: a new therapy to cure cancer patients. Am J Cancer Res. 2012;2:340–56.

    PubMed  PubMed Central  Google Scholar 

  11. Karsten U, Goletz S. What makes cancer stem cell markers different? Springerplus. 2013;2:301

    Article  Google Scholar 

  12. Ma S, Chan KW, Hu L, Lee TK, Wo JY, Ng IO, et al. Identification and characterization of tumorigenic liver cancer stem/progenitor cells. Gastroenterology. 2007;132:2542–56.

    Article  CAS  Google Scholar 

  13. Yang W, Yan HX, Chen L, Liu Q, He YQ, Yu LX, et al. Wnt/beta-catenin signaling contributes to activation of normal and tumorigenic liver progenitor cells. Cancer Res. 2008;68:4287–95.

    Article  CAS  Google Scholar 

  14. Ma S, Chan KW, Lee TK, Tang KH, Wo JY, Zheng BJ, et al. Aldehyde dehydrogenase discriminates the CD133 liver cancer stem cell populations. Mol Cancer Res. 2008;6:1146–53.

    Article  CAS  Google Scholar 

  15. Yang ZF, Ho DW, Ng MN, Lau CK, Yu WC, Ngai P, et al. Significance of CD90+cancer stem cells in human liver cancer. Cancer Cell. 2008;13:153–66.

    Article  CAS  Google Scholar 

  16. Chen MW, Hua KT, Kao HJ, Chi CC, Wei LH, Johansson G, et al. H3K9 histone methyltransferase G9a promotes lung cancer invasion and metastasis by silencing the cell adhesion molecule Ep-CAM. Cancer Res. 2010;70:7830–40.

    Article  CAS  Google Scholar 

  17. Zhu Z, Hao X, Yan M, Yao M, Ge C, Gu J, et al. Cancer stem/progenitor cells are highly enriched in CD133+CD44+population in hepatocellular carcinoma. Int J Cancer. 2010;126:2067–78.

    Article  CAS  Google Scholar 

  18. Zhao W, Wang L, Han H, Jin K, Lin N, Guo T, et al. 1B50-1, a mAb raised against recurrent tumor cells, targets liver tumor-initiating cells by binding to the calcium channel alpha2delta1 subunit. Cancer Cell. 2013;23:541–56.

    Article  CAS  Google Scholar 

  19. Oikawa T, Kamiya A, Zeniya M, Chikada H, Hyuck AD, Yamazaki Y, et al. Sal-like protein 4 (SALL4), a stem cell biomarker in liver cancers. Hepatology. 2013;57:1469–83.

    Article  CAS  Google Scholar 

  20. Liu S, Li N, Yu X, Xiao X, Cheng K, Hu J, et al. Expression of intercellular adhesion molecule 1 by hepatocellular carcinoma stem cells and circulating tumor cells. Gastroenterology. 2013;144:1031–41.

    Article  Google Scholar 

  21. Haraguchi N, Ishii H, Mimori K, Tanaka F, Ohkuma M, Kim HM, et al. CD13 is a therapeutic target in human liver cancer stem cells. J Clin Invest. 2010;120:3326–39.

    Article  CAS  Google Scholar 

  22. Wickstrom M, Larsson R, Nygren P, Gullbo J. Aminopeptidase N (CD13) as a target for cancer chemotherapy. Cancer Sci. 2011;102:501–8.

    Article  Google Scholar 

  23. Yamashita M, Wada H, Eguchi H, Ogawa H, Yamada D, Noda T, et al. A CD13 inhibitor, ubenimex, synergistically enhances the effects of anticancer drugs in hepatocellular carcinoma. Int J Oncol. 2016;49:89–98.

    Article  CAS  Google Scholar 

  24. Sekine KFH, Abe F. Induction of apoptosis by bestatin (ubenimex) in human leukemic cell lines. Leukemia. 1999;13:729–34.

    Article  CAS  Google Scholar 

  25. Osada K, Christie RJ, Kataoka K. Polymeric micelles from poly(ethylene glycol)-poly(amino acid) block copolymer for drug and gene delivery. J R Soc Interface. 2009;6(Suppl 3):S325–39.

    CAS  PubMed  PubMed Central  Google Scholar 

  26. Mishra P, Nayak B, Dey RK. PEGylation in anti-cancer therapy: An overview. Asian J Pharm Sci. 2016;11:337–48.

    Article  Google Scholar 

  27. Jhaveri AM, Torchilin VP. Multifunctional polymeric micelles for delivery of drugs and siRNA. Front Pharmacol. 2014;5:77.

    Article  Google Scholar 

  28. Look ATAR, Shapiro LH, Peiper SC. Human myeloid plasma membrane glycoprotein CD13 (gp150) is identical to aminopeptidase N. J Clin Invest. 1989;83:1299–307.

    Article  CAS  Google Scholar 

  29. Luan Y XW. The structure and main functions of aminopeptidase N. Curr Med Chem. 2007;14:639–47.

    Article  Google Scholar 

  30. Dando I, Cordani M, Dalla Pozza E, Biondani G, Donadelli M, Palmieri M. Antioxidant mechanisms and ROS-related microRNAs in cancer stem cells. Oxid Med Cell Longev. 2015;2015:425708.

    Article  Google Scholar 

  31. Yasunaga M, Fujita Y, Saito R, Oshimura M, Nakajima Y. Continuous long-term cytotoxicity monitoring in 3D spheroids of beetle luciferase-expressing hepatocytes by nondestructive bioluminescence measurement. BMC Biotechnol. 2017;17:54.

    Article  Google Scholar 

  32. Yamada N, Honda Y, Takemoto H, Nomoto T, Matsui M, Tomoda K, et al. Engineering tumour cell-binding synthetic polymers with sensing dense transporters associated with aberrant glutamine metabolism. Sci Rep. 2017;7:6077.

    Article  Google Scholar 

  33. Schwabe RF, Brenner DA. Mechanisms of Liver Injury. I. TNF-alpha-induced liver injury: role of IKK, JNK, and ROS pathways. Am J Physiol Gastrointest Liver Physiol. 2006;290:G583–9.

    Article  CAS  Google Scholar 

  34. Stange T, Kettmann U, Holzhausen H-J. Immunoelectron microscopic single and double labelling of aminopeptidase N (CD 13) and dipeptidyl peptidase IV (CD 26). Acta Histochem. 1996;98:323–31.

    Article  CAS  Google Scholar 

  35. Umezawa HAT, Suda H, Hamada M, Takeuchi TBestatin. an inhibitor of aminopeptidase B, produced by actinomycetes. J Antibiot (Tokyo). 1976;29:97–9.

    Article  CAS  Google Scholar 

  36. Bruley-Rosset MFI, Kiger N, Schulz J, Mathé G. Restoration of impaired immune functions of aged animals by chronic bestatin treatment. Immunology. 1979;38:75–83.

    CAS  PubMed  PubMed Central  Google Scholar 

  37. Terauchi M, Kajiyama H, Shibata K, Ino K, Nawa A, Mizutani S, et al. Inhibition of APN/CD13 leads to suppressed progressive potential in ovarian carcinoma cells. BMC Cancer. 2007;7:140.

    Article  Google Scholar 

  38. Takada M, Fukuoka M, Negoro S, Kusunoki Y, Matsui K, Masuda N, et al. Combination therapy with bestatin in inoperable lung cancer: a randomized trial. Acta Oncol (Madr). 2009;29:821–5.

    Article  Google Scholar 

  39. Niimoto MST, Toi M, Nishiyama M, Hirai T, Yanagawa E, Hattori T. Prospective randomized controlled study on bestatin in resectable gastric cancer--third report. Jpn J Surg. 1990;20:186–91.

    Article  CAS  Google Scholar 

  40. Kumamoto YTT, Tamiya T, Takatsuka K, Furuya S, Yokoyama E, Honma A, et al. Clinical research on prevention of recurrence of superficial bladder cancer--comparative study on clinical efficacy of bleomycin intravesical instillation and bestatin. Hinyokika Kiyo. 1985;31:1861–83.

    CAS  PubMed  Google Scholar 

  41. S. O. A review of clinical studies of bestatin. Recent Results Cancer Res. 1980;75:126–32.

    Article  Google Scholar 

  42. Hitzerd SM, Verbrugge SE, Ossenkoppele G, Jansen G, Peters GJ. Positioning of aminopeptidase inhibitors in next generation cancer therapy. Amino Acids. 2014;46:793–808.

    Article  CAS  Google Scholar 

  43. Mi P, Yanagie H, Dewi N, Yen HC, Liu X, Suzuki M, et al. Block copolymer-boron cluster conjugate for effective boron neutron capture therapy of solid tumors. J Control Release. 2017;254:1–9.

    Article  CAS  Google Scholar 

  44. Fischer DLY, Ahlemeyer B, Krieglstein J, Kissel T. In vitro cytotoxicity testing of polycations: influence of polymer structure on cell viability and hemolysis. Biomaterials. 2003;24:1121–31.

    Article  CAS  Google Scholar 

  45. Lee HJJ, Park TG. PEG grafted polylysine with fusogenic peptide for gene delivery: high transfection efficiency with low cytotoxicity. J Control Release. 2002;79:283–91.

    Article  CAS  Google Scholar 

  46. Webster R, Didier E, Harris P, Siegel N, Stadler J, Tilbury L, et al. PEGylated proteins: evaluation of their safety in the absence of definitive metabolism studies. Drug Metab Dispos. 2007;35:9–16.

    Article  CAS  Google Scholar 

  47. Rusznyak LFM, Szabo G. Lymphatics and lymph circulation. In: Youlten L, editor. Physiology and pathology. 2nd ed. Pergamon Press; Oxford, UK. 1967. p. 475–510.

  48. Tanjaya J, Zhang Y, Lee S, Shi J, Chen E, Ang P, et al. Efficacy of intraperitoneal administration of PEGylated NELL-1 for bone formation. Biores Open Access. 2016;5:159–70.

    Article  CAS  Google Scholar 

  49. Ribas A, Dummer R, Puzanov I, VanderWalde A, Andtbacka RHI, Michielin O, et al. Oncolytic virotherapy promotes intratumoral T cell infiltration and improves anti-PD-1 immunotherapy. Cell. 2017;170:1109–19.

    Article  CAS  Google Scholar 

  50. Talmadge JELB, Pennington R, Long C, Phillips H, Schneider M, Tribble H. Immunomodulatory and therapeutic properties of bestatin in mice. Cancer Res. 1986;46:4505–10.

    CAS  PubMed  Google Scholar 

  51. Yamamoto TNH, Sakon M, Wada H, Eguchi H, Kondo M, Damdinsuren B, et al. Partial contribution of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) TRAIL receptor pathway to antitumor effects of interferon-alpha 5-fluorouracil against hepatocellular carcinoma. Clin Cancer Res. 2004;10:7884–95.

    Article  CAS  Google Scholar 

  52. Ding M, Cao X, Xu HN, Fan JK, Huang HL, Yang DQ, et al. Prostate cancer-specific and potent antitumor effect of a DD3-controlled oncolytic virus harboring the PTEN gene. PLoS ONE. 2012;7:e35153.

    Article  CAS  Google Scholar 

  53. Bijnsdorp IV, Giovannetti E, Peters GJ. Analysis of drug interactions. Methods Mol Biol. 2011;731:421–34.

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank M. Ozaki and Y. Noguchi for technical assistance and the laboratory staff for their helpful discussions.

Funding

This work received financial support from grants-in-aid for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technology (grant no. 17H04282; 17K19698; 16K15615; 15H05791; P-DIRECT; P-CREATE; AMED−Japan Cancer Research Project).

Author contributions

Conception and design: RT, MK, HT, NN, HI. Development of methodology: RT, MK, NN, HI. Acquisition of the data (e.g., provided animals, acquired and managed patients, provided facilities): RT, MK, HT, TN, AA, JK, YU, KM, KA, TO, NN, HI. Analysis and interpretation of the data (e.g., statistical analysis, biostatistics, computational analysis): RT, MK, NH, YI, DY, DS, TA, TK, KK, KG, SK, TS, YD, MM, HI. Writing, review, and/or revision of the manuscript: RT, MK, HE, HT, TN, NH, HI. Study supervision: MM, HI.

Author information

Authors and Affiliations

Authors

Corresponding authors

Correspondence to Masaki Mori or Hideshi Ishii.

Ethics declarations

Conflict of interest

YD, MM, HI received Institutional endowments were received from Taiho Pharmaceutical Co., Ltd., Unitech Co., Ltd. (Chiba, Japan), IDEA Consultants, Inc. (Tokyo, Japan), and Kinshu-kai Medical Corporation (Osaka, Japan); DS, TK, TS, YD, MM received Chugai Co., Ltd., Yakult Honsha Co., Ltd., and Merck & Co., Ltd (YD, MM, TS). The remaining authors declare that they have no conflict of interest.

Electronic supplementary material

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Toshiyama, R., Konno, M., Eguchi, H. et al. Poly(ethylene glycol)–poly(lysine) block copolymer–ubenimex conjugate targets aminopeptidase N and exerts an antitumor effect in hepatocellular carcinoma stem cells. Oncogene 38, 244–260 (2019). https://doi.org/10.1038/s41388-018-0406-x

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41388-018-0406-x

Search

Quick links