CAFs-Derived Exosomal miRNA-130a Confers Cisplatin Resistance of NSCLC Cells Through PUM2-Dependent Packaging.

Chemoresistance is a significant barrier to the treatment and management of non-small cell lung cancer (NSCLC). Exosomes play an essential role in intercellular communication. Understanding the mechanism underlying the role of tumor stroma, especially cancer-associated fibroblasts (CAFs), during chemoresistance would significantly contribute to the clinical application of chemotherapy agents. In this study, we demonstrated that NSCLC-derived CAFs were innately resistant to cisplatin treatment and CAFs-conditioned medium significantly promoted the survival rate of NSCLC cells after cisplatin treatment. Additionally, CAFs-derived exosomes were taken up by NSCLC cells. Moreover, exosomal miRNA-130a was transferred from CAFs to recipient NSCLC cells and knockdown of miRNA-130a reversed the effect of CAFs-derived exosomes during chemoresistance of NSCLC cells. Furthermore, pumilio homolog 2 (PUM2), a RNA-binding protein, mediated the packaging of miRNA-130a into exosomes. The overexpression and knockdown of PUM2 promoted and inhibited tumor growth of xenograft mice, respectively. Taken together, these results suggest that CAFs-derived exosomes confer cisplatin resistance of NSCLC cells through transferring miRNA-130a and that PUM2 is a critical factor for packaging miRNA-130a into exosomes. This study indicates that CAFs-derived exosomal miRNA-130a may be a potential therapeutic target for cisplatin resistance in NSCLC.

Zhang T ，Zhang P ，Li HX 《International Journal of Nanomedicine》

Cancer-associated fibroblasts secreted miR-103a-3p suppresses apoptosis and promotes cisplatin resistance in non-small cell lung cancer.

Wang H ，Huang H ，Wang L ，Liu Y ，Wang M ，Zhao S ，Lu G ，Kang X ... -  《Aging-US》

Exosomal Transfer Of Cisplatin-Induced miR-425-3p Confers Cisplatin Resistance In NSCLC Through Activating Autophagy.

Exosomes are important mediators of intercellular communication. Previously, we characterized circulating exosomal miR-425-3p as a non-invasive prognostic marker for predicting clinical response to platinum-based chemotherapy in patients with non-small cell lung cancer (NSCLC). Circulating exosomal miR-425-3p was validated by qRT-PCR in paired serum samples from NSCLC patients during the course of platinum-based chemotherapy. Cell coculture was performed to examine the effects of exosomal miR-425-3p on the sensitivity of recipient A549 cells to cisplatin. Using bioinformatics, ChIP and luciferase reporter assays, the transcription factor essential for miR-425-3p expression was identified. Autophagic activity in the recipient cells was determined by Western blot and fluorescence microscopy. Higher levels of exosomal miR-425-3p were found in serum samples from the patients in tolerance versus those at baseline. An upward trend in the expression of circulating exosomal miR-425-3p was revealed during chemotherapy. Furthermore, the expression of exosomal miR-425-3p could be induced by cisplatin in NSCLC cells. Exosomes isolated from either cisplatin-treated or cisplatin-resistant NSCLC cells conferred chemoresistance to sensitive A549 cells in a miR-425-3p-dependent manner. Cisplatin-induced c-Myc was found to directly bind the miR-425-3p promoter and transactivated its expression. Exosomal miR-425-3p facilitated autophagic activation in the recipient cells by targeting AKT1, eventually leading to chemoresistance. Our results suggest that apart from a prognostic marker of treatment response, exosomal miR-425-3p might be a potential dynamic biomarker to tailor cisplatin resistance in NSCLC patients during the treatment and represent a promising therapeutic target for therapy-resistant NSCLC.

Ma Y ，Yuwen D ，Chen J ，Zheng B ，Gao J ，Fan M ，Xue W ，Wang Y ，Li W ，Shu Y ，Xu Q ，Shen Y ... -  《International Journal of Nanomedicine》

Cisplatin-resistant NSCLC cells induced by hypoxia transmit resistance to sensitive cells through exosomal PKM2.

Hypoxia is commonly observed in solid tumors and contributes to the resistance of DNA damage drugs. However, the mechanisms behind this resistance are still unclear. In this study, we aimed to explore the effects of hypoxia-induced exosomes on non-small cell lung cancer (NSCLC). Methods: NSCLC cells were subjected to either normoxic or hypoxic conditions to assess cell survival and changes in the expression levels of key proteins. Comparative proteomics were performed to identify exosomal PKM2 in normoxic or hypoxic cisplatin-resistant NSCLC cells-derived exosomes. Functions of hypoxia induced-exosomal PKM2 in promoting cisplatin resistance to NSCLC cells were evaluated both in vitro and in vivo experiments and the molecular mechanisms of hypoxia induced-exosomal PKM2 were demonstrated using flow cytometry, immunoblotting, oxidative stress detection and histological examination. A series of in vitro experiments were performed to evaluate the function of hypoxia-induced exosomes on cancer-associated fibroblasts (CAFs). Results: Hypoxia exacerbated the cisplatin resistance in lung cancer cells due to the increased expression of PKM2 that was observed in the exosomes secreted by hypoxic cisplatin-resistance cells. We identified that hypoxia-induced exosomal PKM2 transmitted cisplatin-resistance to sensitive NSCLC cells in vitro and in vivo. Mechanistically, hypoxia-induced exosomal PKM2 promoted glycolysis in NSCLC cells to produce reductive metabolites, which may neutralize reactive oxygen species (ROS) induced by cisplatin. Additionally, hypoxia-induced exosomal PKM2 inhibited apoptosis in a PKM2-BCL2-dependent manner. Moreover, hypoxia-induced exosomal PKM2 reprogrammed CAFs to create an acidic microenvironment promoting NSCLC cells proliferation and cisplatin resistance. Conclusions: Our findings revealed that hypoxia-induced exosomes transmit cisplatin resistance to sensitive NSCLC cells by delivering PKM2. Exosomal PKM2 may serve as a promising biomarker and therapeutic target for cisplatin resistance in NSCLC.

Wang D ，Zhao C ，Xu F ，Zhang A ，Jin M ，Zhang K ，Liu L ，Hua Q ，Zhao J ，Liu J ，Yang H ，Huang G ... -  《Theranostics》

Cancer-associated fibroblast-derived exosomal microRNA-20a suppresses the PTEN/PI3K-AKT pathway to promote the progression and chemoresistance of non-small cell lung cancer.

Cancer-associated fibroblasts (CAFs) contributes to overall tumor progression. In the current survey, we explored the ability of microRNA-20a (miR-20a) within these CAF-derived exosomes to influence non-small-cell lung cancer (NSCLC) progression. Normal tissue-associated fibroblasts (NAFs) and CAFs were collected from samples of NSCLC patient tumors and paracancerous lung tissues. Exosomes derived from these cells were then characterized via Western blotting, nanoparticle tracking analyses, and transmission electron microscopy. The expression of miR-20a was assessed via qPCR and fluorescence in situ hybridization (FISH). CCK-8, EdU uptake, and colony formation assessments were used for evaluating tumor proliferation, while Hoechst staining was performed to monitor the in vitro apoptotic death of tumor cells. A model of xenograft tumor established in nude mice was also used to evaluate in vivo tumor responses. CAF-derived exosomes exhibited miR-20a upregulation and promoted NSCLC cell proliferation and resistance to cisplatin (DDP). Mechanistically, CAF-derived exosomes were discovered to transmit miR-20a to tumor cells wherein it was able to target PTEN to enhance DDP resistance and proliferation. Associated PTEN downregulation following exosome-derived miR-20a treatment enhanced PI3K/AKT pathway activation. The achieved outcomes explain that CAFs can release miR-20a-containing exosomes capable of promoting NSCLC progression and chemoresistance, highlighting this pathway as a possible therapeutic target in NSCLC.

Shi L ，Zhu W ，Huang Y ，Zhuo L ，Wang S ，Chen S ，Zhang B ，Ke B ... -  《Clinical and Translational Medicine》