Hypoxia-induced exosomes contribute to a more aggressive and chemoresistant ovarian cancer phenotype: a novel mechanism linking STAT3/Rab proteins.
Oncogene
; 37(28): 3806-3821, 2018 07.
Article
en En
| MEDLINE
| ID: mdl-29636548
ABSTRACT
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.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Contexto en salud:
6_ODS3_enfermedades_notrasmisibles
Problema de salud:
6_endocrine_disorders
/
6_ovary_cancer
Asunto principal:
Neoplasias Ováricas
/
Resistencia a Antineoplásicos
/
Proteínas de Unión al GTP rab
/
Factor de Transcripción STAT3
/
Exosomas
/
Hipoxia
Límite:
Animals
/
Female
/
Humans
Idioma:
En
Revista:
Oncogene
Asunto de la revista:
BIOLOGIA MOLECULAR
/
NEOPLASIAS
Año:
2018
Tipo del documento:
Article
País de afiliación:
Estados Unidos