Baseline extracellular vesicle miRNA-30c and autophagic CTCs predict chemoradiotherapy resistance and outcomes in patients with lung cancer

Concurrent chemoradiotherapy (cCRT) is the mainstay of treatment for patients diagnosed with locally advanced non-small cell lung cancer (NSCLC). One significant challenge in the effectiveness of this therapy is the potential development of resistance mechanisms, where autophagy up-regulation has been proposed as a key contributing factor. However, there is a lack of reliable biomarkers to predict outcomes on these patients. Interestingly, for addressing this gap, extracellular vesicles (EVs) and circulating tumor cells (CTCs) have emerged as potential sources of such biomarkers. In this study, we investigated EV-associated miRNAs and presence of autophagic CTCs in prospectively collected serial samples from 38 patients with stage III NSCLC undergoing cCRT. Our findings revealed that non-responders exhibited low levels of baseline EV miR-375, miR-200c, and miR-30c. In particular, EV miR-30c showed high predictive value with an area under the curve of 87.2%. Low EV miR-30c and the presence of autophagic-activated CTCs emerged as independent predictive biomarkers for shorter relapse-free survival and overall survival. Furthermore, in experimental models simulating the effects of chemo- and radiotherapy, the administration of miR-30c, either through direct transfection or encapsulation into human EVs, led to the inhibition of autophagy in these cells. This is the first report demonstrating that EV miR-30c inhibits tumor autophagy and its quantification, together with autophagic-activated CTCs, could be used as biomarkers for the stratification and monitoring of patients with NSCLC undergoing cCRT, and they may hold promising potential for guiding subsequent consolidation treatment with immunotherapy or other novel therapies based on autophagy inhibitors.

Abstract PO-063: Extracellular vesicle miRNAs and autophagic CTCs: Predictive and prognostic biomarkers in radiotherapy treated NSCLC patients

Introduction: Most non-small cell lung carcinoma (NSCLC) patients are diagnosed at advanced stages, when the prognosis is dismal. Thoracic irradiation in combination with chemotherapy have demonstrated to increase the survival of these patients, however, progression is still developed early. The failure of the treatment may be caused by inaccurate patient stratification due to the heterogeneous and evolving nature of tumors that tissue biopsy fails to reflect. Therefore, real-time predictive and prognostic biomarkers are needed to improve the survival of NSCLC patients. In this context, miRNAs are potential markers as they regulate the expression of cancer genes and can be selectively encapsulated into extracellular vesicles (EVs) by cancer cells and found in blood circulation. Similarly, circulating tumor cells (CTCs) are a key event in the metastatic process that shredded into the circulation resemble the features of the tissue of origin. Thus, CTCs can act as tissue surrogates and potential predictive and prognostic factors in these irradiated patients. Recent evidence has associated autophagy activation to an increased resistance to radiotherapy and chemotherapy. However, controversial reports showed a dual role of autophagy during tumor cell survival, thus requiring further research to be done. In this work, we aimed to identify the predictive and prognostic role of specific EV miRNAs and autophagic CTCs in advanced NSCLC patients under concomitant radio-chemotherapy. Methods: This study prospectively enrolled 38 locally advanced NSCLC patients under concomitant radio-chemotherapy (cisplatin-vinorelbine/carboplatin-taxol). Peripheral blood samples were drawn before, during, and after the treatment. CTCs were immunomagnetically isolated and autophagic activity was characterized by immunofluorescence. EVs were isolated by ultracentrifugation methods and specific miRNAs were analyzed by RT-PCR. Internal validation of the predictive model was performed by bootstrap approach. Results: The increase of EV-miR-375 and miR-200c was associated with the reduction of autophagic CTCs along the treatment (p=0.013 & p=0.025). Moreover, baseline levels of EV-miR-375, miR-200c, and miR-30c predicted the response to the treatment with an area under the curve (AUC) of 86%. The presence of autophagic CTCs and low EV-miR-30c were independent prognostic biomarkers for shorter relapse-free survival (p=0.002 & p=0.002) and overall survival (p=0.012 & p<0.001). The analysis of miRNA targets showed that miR-375, miR-200c, and mir30c regulate genes involved in autophagy and cell division such as PIK3CA, potentially modulating radio-chemotherapy resistance. Conclusion: This study reports for the first time that EV-miRNAs and autophagic CTCs are predictive and prognostic biomarkers in advanced NSCLC patients under concomitant radio- chemotherapy. Their identification could serve as tumor surrogates for a real-time treatment stratification of NSCLC patients and might also benefit new combinatory strategies based on autophagy inhibition or immunotherapy.

Citation Format: Diego de Miguel Perez, Rosario Guerrero Tejada, Alessandro Russo, Francisco Gabriel Ortega, Antonio Martínez-Única, Muthukumar Gunasekaran, Jose Antonio Lorente, Jose Exposito, Maria Jose Serrano Fernandez, Christian Rolfo. Extracellular vesicle miRNAs and autophagic CTCs: Predictive and prognostic biomarkers in radiotherapy treated NSCLC patients [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-063.

The efficacy of three-dimensional conformal radiation therapy on pain and quality of life in patients with painful bone metastases: a prospective study

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