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.

microRNAs signature in relapse metastasis and de novo metastasis of breast cancer. A systematic review

miRNAs have been widely identified as important players in cancer development and progression. Metastasis in breast cancer can occur as relapse of a treated primary tumour or at the time of diagnosis of the tumour. The aim of this review is to show if both metastasis are different molecular entities characterised by different miRNA signatures that could be studied as specific biomarkers for each entity. For this, we systematically searched the PubMed, Scopus and Web of Science databases. After searching and reviewing the literature, a total of 30 records were included in this review. Results showed a genetic signature including a total of 5 upregulated miRNAs in metastasis compared with early stages. Of them, miR-23b and miR-200c were exclusively present in relapse metastasis. Finally, we proposed a molecular signature for future studies that can be used as a complementary tool at clinical trials for the diagnosis and characterization of metastasis.

Labeling of Extracellular Vesicles for Monitoring Migration and Uptake in Cartilage Explants

Extracellular vesicles (EVs) are used in different studies to prove their potential as a cell-free treatment due to their cargo derived from their cellular source, such as platelet lysate (PL). When used as treatment, EVs are expected to enter the target cells and effect a response from these. In this research, PL-derived EVs have been studied as a cell-free treatment for osteoarthritis (OA). Thus, a method was set up to label EVs and test their uptake on cartilage explants. PL-derived EVs are labeled with the lipophilic dye PKH26, washed twice through a column, and then tested in an in vitro inflammation-driven OA model for 5 h after particle quantification by nanoparticle tracking analysis (NTA). Hourly, cartilage explants are fixed, paraffined, cut into 6 µm sections to mount on slides, and observed under a confocal microscope. This allows verification of whether EVs enter the target cells (chondrocytes) during this period and analyze their direct effect.

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.

Proteomic analysis of circulating extracellular vesicles identifies potential markers of breast cancer progression, recurrence, and response

Proteomic profiling of circulating small extracellular vesicles (sEVs) represents a promising, noninvasive approach for early detection and therapeutic monitoring of breast cancer (BC). We describe a relatively low-cost, fast, and reliable method to isolate sEVs from plasma of BC patients and analyze their protein content by semiquantitative proteomics. sEV-enriched fractions were isolated from plasma of healthy controls and BC patients at different disease stages before and after surgery. Proteomic analysis of sEV-enriched fractions using reverse phase protein array revealed a signature of seven proteins that differentiated BC patients from healthy individuals, of which FAK and fibronectin displayed high diagnostic accuracy. The size of sEVs was significantly reduced in advanced disease stage, concomitant with a stage-specific protein signature. Furthermore, we observed protein-based distinct clusters of healthy controls, chemotherapy-treated and untreated postsurgery samples, as well as a predictor of high risk of cancer relapse, suggesting that the applied methods warrant development for advanced diagnostics.

Post-Surgery Circulating Tumor Cells and AXL Overexpression as New Poor Prognostic Biomarkers in Resected Lung Adenocarcinoma

Background: The prognosis of early stage non-small cell lung cancer (NSCLC) is quite disappointing and the benefits of adjuvant therapy are relatively small. Thus, there is an urgent need to identify novel prognostic and predictive biomarkers. Lung adenocarcinoma has distinct clinical–pathological characteristics and novel therapeutic strategies are under active evaluation in the adjuvant setting. Here, we investigated the prognostic impact of circulating tumor cells (CTCs) and gene and miRNA tissue expression in resectable NSCLC. Patients and methods: We assessed the association between CTC subpopulations and the outcome of resected early stage lung adenocarcinoma (ADC) patients at three different time-points (CTC1-3) (before surgery, after one month, and after six months) in comparison to squamous cell carcinoma (SCC). Furthermore, gene and miRNA tissue expression, immunoprofiling, and epithelial-to-mesenchymal transition (EMT) markers were correlated with outcome. Results: ADC (n = 47) and SCC (n = 50) revealed different tissue expression profiles, resulting in the presence of different CTC subpopulations. In ADC, miR-155 correlated with AXL and IL6R expression, which were related to the presence of EMT CTC1 (p = 0.014 and p = 0.004). In the multivariate analysis, CTC2 was an independent prognostic factor for relapse-free survival, and CTC3 and AXL were independent prognostic for overall survival only in ADC. Neither the surgery nor the adjuvant treatment influenced the prognosis of these patients. Conclusions: Our study elucidate the prognostic impact of tissue AXL expression and the presence of CTCs after surgery in adenocarcinoma patients. Tissue AXL expression and CTC EMT activation could potentially represent biomarkers for the stratification of ADC patients that might benefit from new adjuvant therapies.

Exosomal miRNA profile as complementary tool in the diagnostic and prediction of treatment response in localized breast cancer under neoadjuvant chemotherapy

BACKGROUND

Breast cancer patients under neoadjuvant chemotherapy includes a heterogeneous group of patients who eventually develop distal disease, not detectable by current methods. We propose the use of exosomal miRNAs and circulating tumor cells as diagnostic and predictive biomarkers in these patients.

METHODS

Fifty-three breast cancer women initially diagnosed with localized breast cancer under neoadjuvant chemotherapy were prospectively enrolled in this study. However, six of them were later re-evaluated and diagnosed as metastatic breast cancer patients by PET-CT scan. Additionally, eight healthy donors were included. Circulating tumor cells and serum exosomal miRNAs were isolated from blood samples before and at the middle of neoadjuvant therapy and exosomal miRNA levels analyzed by qPCR.

RESULTS

Before neoadjuvant therapy, exosomal miRNA-21 and 105 expression levels were higher in metastatic versus non-metastatic patients and healthy donors. Likewise, higher levels of miRNA-222 were observed in basal-like (p = 0.037) and in luminal B versus luminal A (p = 0.0145) tumor subtypes. Exosomal miRNA-222 levels correlated with clinical and pathological variables such as progesterone receptor status (p = 0.017) and Ki67 (p = 0.05). During neoadjuvant treatment, exosomal miRNA-21 expression levels directly correlated with tumor size (p = 0.039) and inversely with Ki67 expression (p = 0.031). Finally, higher levels of exosomal miRNA-21, miRNA-222, and miRNA-155 were significantly associated with the presence of circulating tumor cells.

CONCLUSION

Liquid biopsies based on exosomal miRNAs and circulating tumor cells can be a complementary clinical tool for improving breast cancer diagnosis and prognosis.