Exosomes derived from gemcitabine-resistant cells transfer malignant phenotypic traits via delivery of miRNA-222-3p

Abstract

BackgroundAlthough gemcitabine-based chemotherapy has been established as a core multimodal therapy for non-small cell lung cancer (NSCLC) treatment, its clinical efficacy remains limited by the development of acquired resistance following tumor metastasis and relapse. In this study, we investigated how gemcitabine-resistant (GR) cells contribute to the development of NSCLC tumor malignancy via exosome-mediated transfer of microRNAs.MethodsWe first studied the mechanism of exosome internalization via PKH-67 staining and an immunofluorescence assay, then confirmed our finding by transmission electron microscopy and western blot analysis. Candidate miRNAs were identified through microarray analysis. Thereafter, RT-PCR, MTS, Transwell and soft agar assays were performed to assess the role of exosomic miR-222-3p in vitro. A 3’ untranslated region reporter assay was applied to identify the target of miR-222-3p. A lung metastasis mouse model was constructed to evaluate tumor growth and metastasis in vivo. Finally, clinical samples were used for correlation analysis between exosomic miR-222-3p levels and patients’ response to gemcitabine.ResultsA549-GR–derived exosomes were internalized by receipt cells via caveolin- and lipid raft-dependent endocytosis, which allowed the transfer of miR-222-3p. Exosomic miR-222-3p enhanced the proliferation, gemcitabine resistance, migration, invasion, and anti-anoikis of parental sensitive cells by directly targeting the promoter of SOCS3. In addition, a higher level of exosomic miR-222-3p in sera usually predicted worse prognosis in NSCLC patients.ConclusionOur data demonstrate that exosomic-miR-222-3p functions as a principal regulator of gemcitabine resistance and malignant characteristics by targeting SOCS3. The exosomic miR-222-3p level in sera may be a potential prognostic biomarker for predicting gemcitabine sensitivity in NSCLC patients.Electronic supplementary materialThe online version of this article (doi:10.1186/s12943-017-0694-8) contains supplementary material, which is available to authorized users.

Potential role of exosomes in cancer therapy

“…In addition, the overexpression of exosomal miR‐146a‐5p could reverse the resistance of A549/DDP by targeting Atg12 to inhibit autophagy . Exosomal miR‐222‐3p functioned as a principal regulator of gemcitabine resistance and malignant characteristics by targeting SOCS3, which might be a potential prognostic biomarker for predicting gemcitabine sensitivity in NSCLC patients …”

“…24 Exosomal miR-222-3p functioned as a principal regulator of gemcitabine resistance and malignant characteristics by targeting SOCS3, which might be a potential prognostic biomarker for predicting gemcitabine sensitivity in NSCLC patients. 27…”

Extracellular vesicles: Toward a clinical application in urological cancer treatment

“…reported competition between cancer cells and the surrounding normal epithelial cells through EVs during tumor initiation . A growing body of literature has shown that EVs modulate cancer progression, such as initiation of a premetastatic niche, induction of angiogenesis, destruction of the blood–brain barrier or peritoneum, activation of cancer‐associated fibroblasts and induction of drug resistance . In addition, Ono et al .…”

Exosomes transmit T790M mutation‐induced resistance in EGFR‐mutant NSCLC by activating PI3K/AKT signalling pathway

“…[8][9][10] As mediators between cells, emerging evidences have now indicated that exosomes derived from stromal cells can potentially affect therapeutic response and induce drug resistance of cancer cells. [13][14][15] This has been recognized as a novel mechanism for the "dissemination" of drug resistance. [13][14][15] This has been recognized as a novel mechanism for the "dissemination" of drug resistance.…”

“…By directly binding to the 3′ untranslated regions (UTRs) of target mRNAs, they can deregulate or inhibit protein expression and regulate tumorigenesis, metastization and affect drug responses. 13,15 However, few studies were carried out about the roles of miRNAs transmitted by exosomes in inducing EGFR-TKI resistance in NSCLC. 18 Moreover, researches about the transfer of miR-NAs by exosomes provided reliable evidence to demonstrate the study of using miRNAs carried by exosomes as markers of drug resistance.…”