Apatinib, a selective VEGFR2 inhibitor, improves the delivery of chemotherapeutic agents to tumors by normalizing tumor vessels in LoVo colon cancer xenograft mice


Tumor vascular normalization has been proposed as a therapeutic strategy for malignant neoplasms, which can also interpret the synergistic effect of anti-angiogenesis agents combined with chemotherapy. Apatinib (Apa), a highly selective VEGFR2 inhibitor, attracts much attentions due to its encouraging anticancer activity, especially in the clinical trials of combined treatment. In this study, we investigated whether Apa could promote vascular normalization in tumor in a certain time window. Mice bearing LoVo colon cancer xenograft were orally administrated Apa (150 mg kg−1 per day) for 5, 7, 10, or 12 days. Apa significantly inhibited tumor growth and decreased the microvessel density. Using multi-photon microscopy and electron microscopy, we found that Apa improved tumor vessel morphology by pruning distorted vessel branches and decreased the gap between endothelial cells after a 7-day treatment. Furthermore, Apa decreased vessel leakage and increased pericyte coverage on vascular endothelial cells, suggesting that tumor vessels were more mature and integrated. The intratumoral distribution of adriamycin (ADR) in Apa group was improved from day 7 to 10 without change in plasma drug concentration. Tumor blood perfusion was also increased in this window, and the expression of hypoxia induced factor 1α was downregulated, suggesting the effect of Apa on alleviating tumor hypoxic micro-environment. In conclusion, Apa may improve the effective perfusion of tumor vessels and increase the intratumoral distribution of ADR in a certain time window via normalizing tumor vessels. This normalization window (7 to 10 days of treatment) may contribute to develop a regimen of combined medication in clinic use of Apa.

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  1. 1.

    Hanahan D, Weinberg RA. Hallmarks of cancer: the next generation. Cell. 2011;144:646–74.

  2. 2.

    Folkman J. Tumor angiogenesis: therapeutic implications. N Engl J Med. 1971;285:1182–86.

  3. 3.

    Rao N, Lee YF, Ge R. Novel endogenous angiogenesis inhibitors and their therapeutic potential. Acta Pharmacol Sin. 2015;36:1177–90.

  4. 4.

    Miao Z, Feng J, Ding J. Newly discovered angiogenesis inhibitors and their mechanisms of action. Acta Pharmacol Sin. 2012;33:1103–11.

  5. 5.

    Jain RK. Normalizing tumor vasculature with anti-angiogenic therapy: a new paradigm for combination therapy. Nat Med. 2001;7:987–89.

  6. 6.

    Dickson PV, Hamner JB, Sims TL, Fraga CH, Ng CY, Rajasekeran S, et al. Bevacizumab-induced transient remodeling of the vasculature in neuroblastoma xenografts results in improved delivery and efficacy of systemically administered chemotherapy. Clin Cancer Res. 2007;13:3942–50.

  7. 7.

    Tolaney SM, Boucher Y, Duda DG, Martin JD, Seano G, Ancukiewicz M, et al. Role of vascular density and normalization in response to neoadjuvant bevacizumab and chemotherapy in breast cancer patients. Proc Natl Acad Sci USA. 2015;112:14325–30.

  8. 8.

    Jain RK. Antiangiogenesis strategies revisited: from starving tumors to alleviating hypoxia. Cancer Cell. 2014;26:605–22.

  9. 9.

    Goel S, Duda DG, Xu L, Munn LL, Boucher Y, Fukumura D, et al. Normalization of the vasculature for treatment of cancer and other diseases. Physiol Rev. 2011;91:1071–21.

  10. 10.

    Arjaans M, Schröder CP, Oosting SF, Dafni U, Kleibeuker JE, de Vries EG. VEGF pathway targeting agents, vessel normalization and tumor drug uptake: from bench to bedside. Oncotarget. 2016;7:21247.

  11. 11.

    Franco M, Man S, Chen L, Emmenegger U, Shaked Y, Cheung AM, et al. Targeted anti–vascular endothelial growth factor receptor-2 therapy leads to short-term and long-term impairment of vascular function and increase in tumor hypoxia. Cancer Res. 2006;66:3639–48.

  12. 12.

    Dobosz M, Ntziachristos V, Scheuer W, Strobel S. Multispectral fluorescence ultramicroscopy: three-dimensional visualization and automatic quantification of tumor morphology, drug penetration, and antiangiogenic treatment response. Neoplasia. 2014;16:1W1–13W7.

  13. 13.

    Tian S, Quan H, Xie C, Guo H, Lü F, Xu Y, et al. YN968D1 is a novel and selective inhibitor of vascular endothelial growth factor receptor‐2 tyrosine kinase with potent activity in vitro and in vivo. Cancer Sci. 2011;102:1374–80.

  14. 14.

    Li J, Qin S, Xu J, Guo W, Xiong J, Bai Y, et al. Apatinib for chemotherapy-refractory advanced metastatic gastric cancer: results from a randomized, placebo-controlled, parallel-arm, phase II trial. J Clin Oncol. 2013;31:3219–25.

  15. 15.

    Li F, Zhu T, Cao B, Wang J, Liang L. Apatinib enhances antitumour activity of EGFR-TKIs in non-small cell lung cancer with EGFR-TKI resistance. Eur J Cancer. 2017;84:184–92.

  16. 16.

    Song Z, Lin Y, Xia Zhang CF, Lu Y, Gao Y, Dong C. Cyclic RGD peptide-modified liposomal drug delivery system for targeted oral apatinib administration: enhanced cellular uptake and improved therapeutic effects. Int J Nanomed. 2017;12:1941–58.

  17. 17.

    Peng QX, Han YW, Zhang YL, Hu J, Fan J, Fu SZ, et al. Apatinib inhibits VEGFR-2 and angiogenesis in an in vivo murine model of nasopharyngeal carcinoma. Oncotarget. 2017;8:52813.

  18. 18.

    Tong X, Wang F, Liang S, Zhang X, He JH, Chen XG, et al. Apatinib (YN968D1) enhances the efficacy of conventional chemotherapeutical drugs in side population cells and ABCB1-overexpressing leukemia cells. Biochem Pharmacol. 2012;83:586–97.

  19. 19.

    Mi Y, Liang Y, Huang H, Zhao HY, Wu CP, Wang F, et al. Apatinib (YN968D1) reverses multidrug resistance by inhibiting the efflux function of multiple ATP-binding cassette transporters. Cancer Res. 2010;70:7981–91.

  20. 20.

    Zhang M, Tian Z, Sun Y. Successful treatment of ovarian cancer with apatinib combined with chemotherapy: a case report. Medicine. 2017;96:e8570.

  21. 21.

    Luo C, Shen J, Ying J, Fang X, Wang X, Fu Z, et al. Case report of a KIT-mutated melanoma patient with an excellent response to apatinib and temozolomide combination therapy. OncoTargets Ther. 2017;10:4553–7.

  22. 22.

    Wilson WR, Hay MP. Targeting hypoxia in cancer therapy. Nat Rev Cancer. 2011;11:393–410.

  23. 23.

    Winkler F, Kozin SV, Tong RT, Chae SS, Booth MF, Garkavtsev I, et al. Kinetics of vascular normalization by VEGFR2 blockade governs brain tumor response to radiation: role of oxygenation, angiopoietin-1, and matrix metalloproteinases. Cancer Cell. 2004;6:553–63.

  24. 24.

    Li N, Zheng D, Wei X, Jin Z, Zhang C, Li K. Effects of recombinant human endostatin and its synergy with cisplatin on circulating endothelial cells and tumor vascular normalization in A549 xenograft murine model. J Cancer Res Clin. 2012;138:1131–44.

  25. 25.

    Vangestel C, Van de Wiele C, Van Damme N, Staelens S, Pauwels P, Reutelingsperger CP, et al. 99mTc-(CO) 3 His-annexin A5 micro-SPECT demonstrates increased cell death by irinotecan during the vascular normalization window caused by bevacizumab. J Nucl Med. 2011;52:1786–94.

  26. 26.

    Bekes I, Friedl TWP, Köhler T, Möbus V, Janni W, Wöckel A, et al. Does VEGF facilitate local tumor growth and spread into the abdominal cavity by suppressing endothelial cell adhesion, thus increasing vascular peritoneal permeability followed by ascites production in ovarian cancer. Mol Cancer. 2016;15:13.

  27. 27.

    Gavard J. Endothelial permeability and VE-cadherin: a wacky comradeship. Cell Adhes Migr. 2013;7:465–71.

  28. 28.

    Tolaney SM, Boucher Y, Duda DG, Martin JD, Seano G, Ancukiewicz M, et al. Role of vascular density and normalization in response to neoadjuvant bevacizumab and chemotherapy in breast cancer patients. Proc Natl Acad Sci USA. 2015;112:14325–30.

  29. 29.

    Zhang L, Takara K, Yamakawa D, Kidoya H, Takakura N. Apelin as a marker for monitoring the tumor vessel normalization window during antiangiogenic therapy. Cancer Sci. 2016;107:36–44.

  30. 30.

    Matsumoto S, Batra S, Saito K, Yasui H, Choudhuri R, Gadisetti C, et al. Antiangiogenic agent sunitinib transiently increases tumor oxygenation and suppresses cycling hypoxia. Cancer Res. 2011;71:6350–9.

  31. 31.

    Jain RK. An indirect way to tame cancer. Sci Am. 2014;310:46.

  32. 32.

    Chauhan VP, Boucher Y, Ferrone CR, Roberge S, Martin JD, Stylianopoulos T, et al. Compression of pancreatic tumor blood vessels by hyaluronan is caused by solid stress and not by interstitial fluid pressure. Cancer Cell. 2014;26:14–5.

  33. 33.

    Chauhan VP, Martin JD, Liu H, Lacorre DA, Jain SR, Kozin SV, et al. Angiotensin inhibition enhances drug delivery and potentiates chemotherapy by decompressing tumour blood vessels. Nat Commun. 2013;4:2516.

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This research was financially supported by National Science Foundation of China (81573496, 81773989, 81530098, and 81573494), China “Creation of New Drugs” Key Technology Projects (2015ZX09501001), Jiangsu Province Nature Science Foundation (BK20160076), Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYLX16_1203), and the Project Program of State Key Laboratory of Natural Medicines, China Pharmaceutical University (SKLNMZZCX201608). We also appreciated the help from Dr. Lei He (Southeast University, China) for her kindly assists on working with multi-photon laser scanning microscope.

Author contributions

FZ and G-jW designed the research. KZ, J-wZ, and FZ performed the research and wrote the paper. J-wZ, Q-yW, W-yL, J-iL, LY, M-mC, S-yN, and Q-yC participated in parts of the research. Competing interests: The authors declare no competing interests.

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Correspondence to Guang-ji Wang or Fang Zhou.

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  • apatinib
  • anti-angiogenesis
  • tumor vessel
  • normalization window
  • combined therapy
  • adriamycin
  • colon cancer.

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