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Hypoxia-induced exosomes contribute to a more aggressive and chemoresistant ovarian cancer phenotype: a novel mechanism linking STAT3/Rab proteins

Oncogenevolume 37pages38063821 (2018) | Download Citation


Hypoxia-mediated tumor progression, metastasis, and drug resistance are major clinical challenges in ovarian cancer. Exosomes released in the hypoxic tumor microenvironment may contribute to these challenges by transferring signaling proteins between cancer cells and normal cells. We observed that ovarian cancer cells exposed to hypoxia significantly increased their exosome release by upregulating Rab27a, downregulating Rab7, LAMP1/2, NEU-1, and also by promoting a more secretory lysosomal phenotype. STAT3 knockdown in ovarian cancer cells reduced exosome release by altering the Rab family proteins Rab7 and Rab27a under hypoxic conditions. We also found that exosomes from patient-derived ascites ovarian cancer cell lines cultured under hypoxic conditions carried more potent oncogenic proteins—STAT3 and FAS that are capable of significantly increasing cell migration/invasion and chemo-resistance in vitro and tumor progression/metastasis in vivo. Hypoxic ovarian cancer cells derived exosomes (HEx) are proficient in re-programming the immortalized fallopian tube secretory epithelial cells (FT) to become pro-tumorigenic in mouse fallopian tubes. In addition, cisplatin efflux via exosomes was significantly increased in ovarian cancer cells under hypoxic conditions. Co-culture of HEx with tumor cells led to significantly decreased dsDNA damage and increased cell survival in response to cisplatin treatment. Blocking exosome release by known inhibitor Amiloride or STAT3 inhibitor and treating with cisplatin resulted in a significant increase in apoptosis, decreased colony formation, and proliferation. Our results demonstrate that HEx are more potent in augmenting metastasis/chemotherapy resistance in ovarian cancer and may serve as a novel mechanism for tumor metastasis, chemo-resistance, and a point of intervention for improving clinical outcomes.

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  1. 1.

    Finger EC, Giaccia AJ. Hypoxia, inflammation, and the tumor microenvironment in metastatic disease. Cancer Metastas Rev. 2010;29:285–93.

  2. 2.

    Lengyel E. Ovarian cancer development and metastasis. Am J Pathol. 2010;177:1053–64.

  3. 3.

    Selvendiran K, Bratasz A, Kuppusamy ML, Tazi MF, Rivera BK, Kuppusamy P. Hypoxia induces chemoresistance in ovarian cancer cells by activation of signal transducer and activator of transcription 3. Int J Cancer. 2009;125:2198–204.

  4. 4.

    SEER Stat Fact Sheets: Ovary Cancer (2015).

  5. 5.

    Holmes D. Ovarian cancer: beyond resistance. Nature. 2015;527:S217.

  6. 6.

    Kulbe H, Chakravarty P, Leinster DA, Charles KA, Kwong J, Thompson RG, et al. A dynamic inflammatory cytokine network in the human ovarian cancer microenvironment. Cancer Res. 2012;72:66–75.

  7. 7.

    Beach A, Zhang HG, Ratajczak MZ, Kakar SS. Exosomes: an overview of biogenesis, composition and role in ovarian cancer. J Ovarian Res. 2014;7:14.

  8. 8.

    Dorayappan KDP, W J, Saini U, Bixel K, Riley M, Zingarelli R, Wanner R, Cohn D, Selvendiran K. Hypoxia-facilitated exosomal release from ovarian cancer cells is regulated by STAT3 and is associated with increased metastatic tumor burden. Gynecol Oncol. 2016;141(Supp.1):66.

  9. 9.

    Azmi AS, Bao B, Sarkar FH. Exosomes in cancer development, metastasis, and drug resistance: a comprehensive review. Cancer Metastas- Rev. 2013;32:623–42.

  10. 10.

    Zhang HG, Grizzle WE. Exosomes: a novel pathway of local and distant intercellular communication that facilitates the growth and metastasis of neoplastic lesions. Am J Pathol. 2014;184:28–41.

  11. 11.

    Vaksman O, Trope C, Davidson B, Reich R. Exosome-derived miRNAs and ovarian carcinoma progression. Carcinogenesis. 2014;35:2113–20.

  12. 12.

    Teng Y, Ren Y, Hu X, Mu J, Samykutty A, Zhuang X, et al. MVP-mediated exosomal sorting of miR-193a promotes colon cancer progression. Nat Commun. 2017;8:14448.

  13. 13.

    Au Yeung CL, Co NN, Tsuruga T, Yeung TL, Kwan SY, Leung CS, et al. Exosomal transfer of stroma-derived miR21 confers paclitaxel resistance in ovarian cancer cells through targeting APAF1. Nat Commun. 2016;7:11150.

  14. 14.

    Su SA, Xie Y, Fu Z, Wang Y, Wang JA, Xiang M. Emerging role of exosome-mediated intercellular communication in vascular remodeling. Oncotarget. 2017;8:25700–12.

  15. 15.

    Chen Y, Zeng C, Zhan Y, Wang H, Jiang X, Li W. Aberrant low expression of p85alpha in stromal fibroblasts promotes breast cancer cell metastasis through exosome-mediated paracrine Wnt10b. Oncogene. 2017;36:4692–705.

  16. 16.

    Ostrowski M, Carmo NB, Krumeich S, Fanget I, Raposo G, Savina A, et al. Rab27a and Rab27b control different steps of the exosome secretion pathway. Nat Cell Biol. 2010;12:19–30.

  17. 17.

    Kirkegaard T, Jaattela M. Lysosomal involvement in cell death and cancer. Biochim Et Biophys Acta. 2009;1793:746–54.

  18. 18.

    Kallunki T, Olsen OD, Jaattela M. Cancer-associated lysosomal changes: friends or foes? Oncogene. 2013;32:1995–2004.

  19. 19.

    Safaei R, Larson BJ, Cheng TC, Gibson MA, Otani S, Naerdemann W, et al. Abnormal lysosomal trafficking and enhanced exosomal export of cisplatin in drug-resistant human ovarian carcinoma cells. Mol Cancer Ther. 2005;4:1595–604.

  20. 20.

    McCann GA, Naidu S, Rath KS, Bid HK, Tierney BJ, Suarez A, et al. Targeting constitutively-activated STAT3 in hypoxic ovarian cancer, using a novel STAT3 inhibitor. Oncoscience. 2014;1:216–28.

  21. 21.

    Saini U, Naidu S, ElNaggar AC, Bid HK, Wallbillich JJ, Bixel K, et al. Elevated STAT3 expression in ovarian cancer ascites promotes invasion and metastasis: a potential therapeutic target. Oncogene. 2016;36:168–81.

  22. 22.

    Kahlert C, Kalluri R. Exosomes in tumor microenvironment influence cancer progression and metastasis. J Mol Med. 2013;91:431–7.

  23. 23.

    Kalluri R. The biology and function of exosomes in cancer. J Clin Investig. 2016;126:1208–15.

  24. 24.

    Hoshino A, Costa-Silva B, Shen TL, Rodrigues G, Hashimoto A, Tesic Mark M, et al. Tumour exosome integrins determine organotropic metastasis. Nature. 2015;527:329–35.

  25. 25.

    Kucharzewska P, Christianson HC, Welch JE, Svensson KJ, Fredlund E, Ringner M, et al. Exosomes reflect the hypoxic status of glioma cells and mediate hypoxia-dependent activation of vascular cells during tumor development. Proc Natl Acad Sci USA. 2013;110:7312–7.

  26. 26.

    Leca J, Martinez S, Lac S, Nigri J, Secq V, Rubis M, et al. Cancer-associated fibroblast-derived annexin A6 + extracellular vesicles support pancreatic cancer aggressiveness. J Clin Investig. 2016;126:4140–56.

  27. 27.

    Yogalingam G, Bonten EJ, van de Vlekkert D, Hu H, Moshiach S, Connell SA, et al. Neuraminidase 1 is a negative regulator of lysosomal exocytosis. Dev Cell. 2008;15:74–86.

  28. 28.

    Vanlandingham PA, Ceresa BP. Rab7 regulates late endocytic trafficking downstream of multivesicular body biogenesis and cargo sequestration. J Biol Chem. 2009;284:12110–24.

  29. 29.

    Kreuzaler PA, Staniszewska AD, Li W, Omidvar N, Kedjouar B, Turkson J, et al. Stat3 controls lysosomal-mediated cell death in vivo. Nat Cell Biol. 2011;13:303–9.

  30. 30.

    Wang T, Gilkes DM, Takano N, Xiang L, Luo W, Bishop CJ, et al. Hypoxia-inducible factors and RAB22A mediate formation of microvesicles that stimulate breast cancer invasion and metastasis. Proc Natl Acad Sci USA. 2014;111:E3234–3242.

  31. 31.

    Liang B, Peng P, Chen S, Li L, Zhang M, Cao D, et al. Characterization and proteomic analysis of ovarian cancer-derived exosomes. J Proteomics. 2013;80:171–82.

  32. 32.

    Shender VO, Pavlyukov MS, Ziganshin RH, Arapidi GP, Kovalchuk SI, Anikanov NA, et al. Proteome-metabolome profiling of ovarian cancer ascites reveals novel components involved in intercellular communication. Mol Cell Proteomics. 2014;13:3558–71.

  33. 33.

    Sceneay J, Smyth MJ, Moller A. The pre-metastatic niche: finding common ground. Cancer Metastas Rev. 2013;32:449–64.

  34. 34.

    Costa-Silva B, Aiello NM, Ocean AJ, Singh S, Zhang H, Thakur BK, et al. Pancreatic cancer exosomes initiate pre-metastatic niche formation in the liver. Nat Cell Biol. 2015;17:816–26.

  35. 35.

    Lobb RJ, Lima LG, Moller A. Exosomes: Key mediators of metastasis and pre-metastatic niche formation. Semin Cell Dev Biol. 2017;67:3–10.

  36. 36.

    Grange C, Tapparo M, Collino F, Vitillo L, Damasco C, Deregibus MC, et al. Microvesicles released from human renal cancer stem cells stimulate angiogenesis and formation of lung premetastatic niche. Cancer Res. 2011;71:5346–56.

  37. 37.

    Graves LE, Ariztia EV, Navari JR, Matzel HJ, Stack MS, Fishman DA. Proinvasive properties of ovarian cancer ascites-derived membrane vesicles. Cancer Res. 2004;64:7045–9.

  38. 38.

    Kanlikilicer P, Rashed MH, Bayraktar R, Mitra R, Ivan C, Aslan B, et al. Ubiquitous release of exosomal tumor suppressor miR-6126 from ovarian cancer cells. Cancer Res. 2016;76:7194–207.

  39. 39.

    Safaei R, Katano K, Larson BJ, Samimi G, Holzer AK, Naerdemann W, et al. Intracellular localization and trafficking of fluorescein-labeled cisplatin in human ovarian carcinoma cells. Clin Cancer Res. 2005;11(Pt 1):756–67.

  40. 40.

    Saini U, Naidu S, ElNaggar AC, Bid HK, Wallbillich JJ, Bixel K, et al. Elevated STAT3 expression in ovarian cancer ascites promotes invasion and metastasis: a potential therapeutic target. Oncogene. 2017;36:168–81.

  41. 41.

    Rath KS, Naidu SK, Lata P, Bid HK, Rivera BK, McCann GA, et al. HO-3867, a safe STAT3 inhibitor, is selectively cytotoxic to ovarian cancer. Cancer Res. 2014;74:2316–27.

  42. 42.

    Chacko SM, Ahmed S, Selvendiran K, Kuppusamy ML, Khan M, Kuppusamy P. Hypoxic preconditioning induces the expression of prosurvival and proangiogenic markers in mesenchymal stem cells. Am J Physiol Cell Physiol. 2010;299:C1562–70.

  43. 43.

    Zhang W, Peng P, Kuang Y, Yang J, Cao D, You Y, et al. Characterization of exosomes derived from ovarian cancer cells and normal ovarian epithelial cells by nanoparticle tracking analysis. Tumour Biol. 2016;37:4213–21.

  44. 44.

    Savina A, Vidal M, Colombo MI. The exosome pathway in K562 cells is regulated by Rab11. J Cell Sci. 2002;115(Pt 12):2505–15.

  45. 45.

    Gupta S, Knowlton AA. HSP60 trafficking in adult cardiac myocytes: role of the exosomal pathway. Am J Physiol Heart Circ Physiol. 2007;292:H3052–6.

  46. 46.

    Gao M, Kim YK, Zhang C, Borshch V, Zhou S, Park HS, et al. Direct observation of liquid crystals using cryo-TEM: specimen preparation and low-dose imaging. Microsc Res Tech. 2014;77:754–72.

  47. 47.

    ElNaggar AC, Saini U, Naidu S, Wanner R, Sudhakar M, Fowler J, et al. Anticancer potential of diarylidenyl piperidone derivatives, HO-4200 and H-4318, in cisplatin resistant primary ovarian cancer. Cancer Biol Ther. 2016;17:1107–15.

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We thank Dr. Zhang Liwen, PhD for proteomic analysis using Fusion Orbitrap instrument at OSU supported by NIH Award Number Grant S10 OD018056; Dr. Xiaokui Mo, Ph.D for analysis of Bioinformatics data; and Dr. Min Gao, Ph.D, Kent University for TEM analysis. Confocal images presented in this manuscript were generated using the services of the Campus Microscopy and Imaging Facility at OSU supported in part by grant P30 CA016058, National Cancer Institute, Bethesda, MD. We also thank Dr. John Olesik, Trace Element Research laboratory at OSU who helped us to quantify the Cisplatin concentration in exosomes by ICP-Mass Spectrometry; Dr. John Hays for his willingness to pre-review this manuscript and provide valuable comments and suggestions; Dr. Matthew Ringel, MD and his laboratory member Dr. Moto Saji for their invaluable help in exosome isolation protocols; and Brentley Smith, GYN/ONC fellow at OSU, Graduate students Dongju Park and Christopher Koivisto, Medical student Rashmi Madhukar, and Undergraduate student Maria Riley, for the IHC, cell culture, and basic assay help. This work was funded by Ovarian Cancer Research Fund (OCRF), NCI RO1-CA176078 grant (to KS and DEC) and KOH ovarian cancer foundation grant to KDPD.

Author contributions

KS, KDPD, and DEC designed all experiments. KDPD and RW performed most of the in vitro and in vivo studies, exosome isolation, STAT3 knockdown experiments, patient ascites cell characterization, cisplatin measurement, and analyzed the data collected. JJW and RZ collected patient ascites and performed WB. AAS performed the tumor histopathology. US performed the transfection work. KDPD, JJW, DEC, and KS wrote, edited, and proofread the manuscript.

Author information


  1. Division of Gynecologic Oncology, Comprehensive Cancer Center, The Ohio State University Wexner Medical Center, Columbus, OH, USA

    • Kalpana Deepa Priya Dorayappan
    • , Ross Wanner
    • , Uksha Saini
    • , Roman Zingarelli
    • , David E. Cohn
    •  & Karuppaiyah Selvendiran
  2. Department of OB/GYN, Division of Gynecologic Oncology, Georgia Cancer Center, Augusta University, Augusta, GA, USA

    • John J. Wallbillich
  3. Department of Pathology, Gynecologic Oncology, Comprehensive Cancer Center, The Ohio State University Wexner Medical Center, Columbus, OH, USA

    • Adrian A. Suarez


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The authors declare that they have no conflict of interest.

Corresponding author

Correspondence to Karuppaiyah Selvendiran.

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