Monitoring with circulating tumor cells in the perioperative setting of patients with surgically treated stages I-IIIA NSCLC.

Background: Surgery is regarded as the treatment's cornerstone for early stage and locally advanced non-small cell lung cancer (NSCLC) whenever the tumor is considered resectable. Liquid biopsy is one of the most promising research areas in oncology in the last 10 years, providing a useful non-invasive tool to detect and monitor cancer. The prognostic value of circulating tumor cells (CTCs) has been studied in different cancer types and had been related with a higher risk of relapse and worse prognosis. The aim of this study is to evaluate the prognostic value of CTC detection in patients with stage I-IIIA NSCLC treated with surgery. Methods: We conducted a prospective, single-center study of 180 consecutive patients with resected and pathological confirmed stage I to IIIA (TNM AJCC/UICC 8th edition) NSCLC. Patients' blood samples were processed and CTCs were characterized before and after the surgery. A cohort of patients had CTC determination after chemotherapy and surgery. Cut-off points were established in 1 and 5 CTCs for statistical analysis. Results: A proportion of 76.7% had at least 1 CTC before the surgery, and 30.6% had 5 or more, while 55.9% had at least 1 CTC after surgery, and 8.3% had 5 or more. We found no correlation between preoperative CTC detection for a cut-off of 5 with neither overall survival (OS) [hazard ratio (HR): 0.99, P=0.887], disease-free survival (DFS) (HR: 0.95, P=0.39) nor relapse (32.7% vs. 28.8%, P=0.596). We also did not find a correlation between postoperative CTCs detection for a cut-off of 5 with either OS (HR: 1.01, P=0.808), DFS (HR: 0.95, P=0.952) or relapse (26.7% vs. 29.5%, P=0.83). The mean change in the number of CTCs over time between preoperative and postoperative samples was 2.13, with a standard deviation of 6.78. Conclusions: Despite the large cohort of patients included in this study, CTC monitoring in the perioperative setting was not correlated with relapse, DFS or OS in our study, and therefore cannot be recommended as a reliable biomarker for minimal residual disease (MRD) after surgery.

Clinical and molecular parameters associated to pneumonitis development in non-small-cell lung cancer patients receiving chemoimmunotherapy from NADIM trial.

BACKGROUND: Pneumonitis (Pn) is one of the main immune-related adverse effects, having a special importance in lung cancer, since they share affected tissue. Despite its clinical relevance, Pn development remains an unpredictable treatment adverse effect, whose mechanisms are mainly unknown, being even more obscure when it is associated to chemoimmunotherapy. METHODS: In order to identify parameters associated to treatment related Pn, we analyzed clinical variables and molecular parameters from 46 patients with potentially resectable stage IIIA non-small-cell lung cancer treated with neoadjuvant chemoimmunotherapy included in the NADIM clinical trial (NCT03081689). Pn was defined as clinical or radiographic evidence of lung inflammation without alternative diagnoses, from treatment initiation to 180 days. RESULTS: Among 46 patients, 12 developed Pn (26.1%). Sex, age, smoking status, packs-year, histological subtype, clinical or pathological response, progression-free survival, overall survival and number of nivolumab cycles, were not associated to Pn development. Regarding molecular parameters at diagnosis, Pn development was not associated to programmed death ligand 1, TPS, T cell receptor repertoire parameters, or tumor mutational burden. However, patients who developed Pn had statistically significant lower blood median levels of platelet to monocyte ratio (p=0.012) and teratocarcinoma-derived growth factor 1 (p=0.013; area under the curve (AUC) 0.801), but higher median percentages of natural killers (NKs) (p=0.019; AUC 0.786), monocytes (p=0.017; AUC 0.791), MSP (p=0.006; AUC 0.838), PARN (p=0.017; AUC 0.790), and E-Cadherin (p=0.022; AUC 0.788). In addition, the immune scenario of Pn after neoadjuvant treatment involves: high levels of neutrophils and NK cells, but low levels of B and T cells in peripheral blood; increased clonality of intratumoral T cells; and elevated plasma levels of several growth factors (EGF, HGF, VEGF, ANG-1, PDGF, NGF, and NT4) and inflammatory cytokines (MIF, CCL16, neutrophil gelatinase-associated lipocalin, BMP-4, and u-PAR). CONCLUSIONS: Although statistically underpowered, our results shed light on the possible mechanisms behind Pn development, involving innate and adaptative immunity, and open the possibility to predict patients at high risk. If confirmed, this may allow the personalization of both, the surveillance strategy and the therapeutic approaches to manage Pn in patients receiving chemoimmunotherapy.

Blood biomarkers associated to complete pathological response on NSCLC patients treated with neoadjuvant chemoimmunotherapy included in NADIM clinical trial.

BACKGROUND: Immunotherapy is being tested in early-stage non-small cell lung cancer (NSCLC), and achieving higher rates of complete pathological responses (CPR) as compared to standard of care. Early identification of CPR patients has vital clinical implications. In this study, we focused on basal peripheral immune cells and their treatment-related changes to find biomarkers associated to CPR. METHODS: Blood from 29 stage IIIA NSCLC patients participating in the NADIM trial (NCT03081689) was collected at diagnosis and post neoadjuvant treatment. More than 400 parameters of peripheral blood mononuclear cells (PBMCs) phenotype and plasma soluble factors were analyzed. RESULTS: Neoadjuvant chemoimmunotherapy altered more than 150 immune parameters. At diagnosis, 11 biomarkers associated to CPR were described, with an area under the ROC curve >0.70 and p-value <.05. CPR patients had significantly higher levels of CD4+ PD-1+ cells, NKG2D, and CD56 expression on T CD56 cells, intensity of CD25 expression on CD4+ CD25hi+ cells and CD69 expression on intermediate monocytes; but lower levels of CD3+ CD56- CTLA-4+ cells, CD14++ CD16+ CTLA-4+ cells, CTLA-4 expression on T CD56 cells and lower levels of b-NGF, NT-3, and VEGF-D in plasma compared to non-CPR. Post treatment, CPR patients had significantly higher levels of CD19 expression on B cells, BCMA, 4-1BB, MCSF, and PARC and lower levels of MPIF-1 and Flt-3L in plasma compared to non-CPR. CONCLUSIONS: Patients achieving CPR seem to have a distinctive peripheral blood immune status at diagnosis, even showing different immune response to treatment. These results reinforce the different biology behind CPR and non-CPR responses.

Cisplatin resistance involves a metabolic reprogramming through ROS and PGC-1α in NSCLC which can be overcome by OXPHOS inhibition.

BACKGROUND: Platinum-based chemotherapy remains the standard of care for most lung cancer cases. However chemoresistance is often developed during the treatment, limiting clinical utility of this drug. Recently, the ability of tumor cells to adapt their metabolism has been associated to resistance to therapies. In this study, we first described the metabolic reprogramming of Non-Small Cell Lung Cancer (NSCLC) in response to cisplatin treatment. METHODS: Cisplatin-resistant versions of the A549, H1299, and H460 cell lines were generated by continuous drug exposure. The long-term metabolic changes, as well as, the early response to cisplatin treatment were analyzed in both, parental and cisplatin-resistant cell lines. In addition, four Patient-derived xenograft models treated with cisplatin along with paired pre- and post-treatment biopsies from patients were studied. Furthermore, metabolic targeting of these changes in cell lines was performed downregulating PGC-1α expression through siRNA or using OXPHOS inhibitors (metformin and rotenone). RESULTS: Two out of three cisplatin-resistant cell lines showed a stable increase in mitochondrial function, PGC1-α and mitochondrial mass with reduced glycolisis, that did not affect the cell cycle. This phenomenon was confirmed in vivo. Post-treatment NSCLC tumors showed an increase in mitochondrial mass, PGC-1α, and a decrease in the GAPDH/MT-CO1 ratio. In addition, we demonstrated how a ROS-mediated metabolism reprogramming, involving PGC-1α and increased mitochondrial mass, is induced during short-time cisplatin exposure. Moreover, we tested how cells with increased PGC-1a induced by ZLN005 treatment, showed reduced cisplatin-driven apoptosis. Remarkably, the long-term metabolic changes, as well as the metabolic reprogramming during short-time cisplatin exposure can be exploited as an Achilles' heel of NSCLC cells, as demonstrated by the increased sensitivity to PGC-1α interference or OXPHOS inhibition using metformin or rotenone. CONCLUSION: These results describe a new cisplatin resistance mechanism in NSCLC based on a metabolic reprogramming that is therapeutically exploitable through PGC-1α downregulation or OXPHOS inhibitors.

Cancer-associated fibroblasts modify lung cancer metabolism involving ROS and TGF-ß signaling.

Lung cancer is a major public health problem due to its high incidence and mortality rate. The altered metabolism in lung cancer is key for the diagnosis and has implications on both, the prognosis and the response to treatments. Although Cancer-associated fibroblasts (CAFs) are one of the major components of the tumor microenvironment, little is known about their role in lung cancer metabolism. We studied tumor biopsies from a cohort of 12 stage IIIA lung adenocarcinoma patients and saw a positive correlation between the grade of fibrosis and the glycolysis phenotype (Low PGC-1α and High GAPDH/MT-CO1 ratio mRNA levels). These results were confirmed and extended to other metabolism-related genes through the in silico data analysis from 73 stage IIIA lung adenocarcinoma patients available in TCGA. Interestingly, these relationships are not observed with the CAFs marker α-SMA in both cohorts. To characterize the mechanism, in vitro co-culture studies were carried out using two NSCLC cell lines (A549 and H1299 cells) and two different fibroblast cell lines. Our results confirm that a metabolic reprogramming involving ROS and TGF-ß signaling occurs in lung cancer cells and fibroblasts independently of α-SMA induction. Under co-culture conditions, Cancer-Associated fibroblasts increase their glycolytic ability. On the other hand, tumor cells increase their mitochondrial function. Moreover, the differential capability among tumor cells to induce this metabolic shift and also the role of the basal fibroblasts Oxphos Phosphorylation (OXPHOS) function modifying this phenomenon could have implications on both, the diagnosis and prognosis of patients. Further knowledge in the mechanism involved may allow the development of new therapies.

Prognostic value of quantitative ctDNA levels in non small cell lung cancer patients.

BACKGROUND: Circulating tumor DNA (ctDNA) levels correlate well with tumor bulk. In this paper we aim to estimate the prognostic value of the dynamic quantification of ctDNA levels. MATERIALS AND METHODS: A total of 251 serial plasma samples from 41 non-small-cell lung cancer patients who carried an activating EGFR mutation were analysed by digital PCR. For survival analysis, ctDNA levels were computed as a time-dependent covariate. RESULTS: Dynamic ctDNA measurements had prognostic significance (hazard ratio for overall survival and progression free survival according to p.T790M mutant allele frequency; 2.676 and 2.71 respectively; P < 0.05). In the same way, patients with p.T790M-negative or unchanging or decreasing plasma levels of sensitizing EGFR mutation were 12 and 4.8 times more likely to maintain response or stable disease, respectively, than patients in which the opposite occurred (P < 0.05).On average, the p.T790M mutation was detected in plasma 51 days before the assessment of progression disease by CT-scan. Finally, ctDNA outperformed CTCs for assessing tumor progression (P = 0.021). CONCLUSIONS: The appearance or increase in a unit of the p.T790M allele frequency almost triples the risk of death and progression. This information can be used to design clinical trials aiming to estimate whether T790M positive patients should start second line treatment based on molecular data rather than imaging data.

PGC-1alpha levels correlate with survival in patients with stage III NSCLC and may define a new biomarker to metabolism-targeted therapy.

Lung cancer remains the leading cause of cancer-related death worldwide, with one-third diagnosed with locally advanced (stage III) disease. Preoperative induction chemo-radiotherapy is key for the treatment of these patients, however conventional cisplatin based approaches has apparently reached a plateau of effectiveness. In the search for new therapies, the targeting of tumor metabolism is revealed as an interesting option to improve the patient's responses. Here we describe the importance of PGC-1alpha and GAPDH/MT-CO1 ratio levels as surrogates of the Warburg effect from a series of 28 stage III NSCLC patients, on PFS, OS and PET uptake. Moreover, our results show a great variability between tumors of different individuals, ranging from very glycolytic to more OXPHOS-dependent tumors, which compromises the success of therapies directed to metabolism. In this sense, using 3 different cell lines, we describe the relevance of Warburg effect on the response to metabolism-targeted therapies. Specifically, we show that the inhibitory effect of metformin on cell viability depends on cell's dependence on the OXPHOS system. The results on cell lines, together with the results of PGC-1alpha and GAPDH/MT-CO1 as biomarkers on patient's biopsies, would point out what type of patients would benefit more from the use of these drugs.

Concordance between circulating tumor cells and clinical status during follow-up in anaplastic lymphoma kinase (ALK) non-small-cell lung cancer patients.

BACKGROUND: The identification of anaplastic lymphoma kinase (ALK) rearrangements is found in approximately 5% of non-small-cell lung cancers (NSCLCs). However, the development of liquid biopsies as a diagnostic tool is less developed in these cases. This study investigates the use of CTCs during treatment, together with an extended follow-up to correlate with clinical evolution. PATIENTS AND METHODS: A total of 13 patients out of a cohort of 212 patients with lung adenocarcinoma, presented ALK rearrangements (6%) confirmed by tumor biopsy. A total of 60 serial blood samples were collected from these patients who were prospectively enrolled in the study. RESULTS: All patients had a positive CTC count at baseline (mean = 3). The median follow-up was 9 months (range 1-17 months). Three patients underwent surgery and their CTC counts decreased after the procedure but still remained detectable. After radiotherapy, 3 cases showed an average decrease of 5 CTCs. A total of 6 patients were treated with ALK inhibitors and a partial response was observed in 3 of them, who also presented decreased CTC counts. The other 3 patients presented primary resistance, and their CTC counts were higher than those obtained prior to progression. CONCLUSION: We believe that the use of CTCs for dynamic monitoring of NSCLC with ALK rearrangement and to detect disease persistence or recurrence may be a reliable technique. CTC counts may also have potential use to monitor the efficacy of ALK inhibitors, facilitating detection of resistance to treatment.

APRIL promotes breast tumor growth and metastasis and is associated with aggressive basal breast cancer.

APRIL (a proliferation-inducing ligand) is a cytokine of the tumor necrosis factor family associated mainly with hematologic malignancies. APRIL is also overexpressed in breast carcinoma tissue lesions, although neither its role in breast tumorigenesis nor the underlying molecular mechanism is known. Here, we show that several breast cancer cell lines express APRIL and both its receptors, B cell maturation antigen (BCMA) and transmembrane activator and CAML-interactor (TACI), independently of luminal or basal tumor cell phenotype, and that the mitogen-activated protein kinases p38, ERK1/2, and JNK1/2 are activated in response to APRIL. The inflammatory stimulus poly I:C, a toll-like receptor (TLR) 3 ligand, enhanced APRIL secretion. Silencing experiments decreased cell proliferation, demonstrating that APRIL is a critical autocrine factor for breast tumor growth. Studies of 4T1 orthotopic breast tumors in APRIL transgenic mice showed that an APRIL-enriched environment increased tumor growth and promoted lung metastasis associated with enhanced tumor cell proliferation; BCMA and TACI expression suggests that both participate in these processes. We detected APRIL, BCMA and TACI in human luminal, triple-negative breast carcinomas and HER2 breast carcinomas, with increased levels in more aggressive basal tumors. APRIL was observed near Ki67(+) nuclei and was distributed heterogeneously in the cancer cells, in the leukocyte infiltrate, and in the myoepithelial layer adjacent to the tumor area; these results imply that APRIL provides proliferation signals to tumor cells through paracrine and autocrine signaling. Our study identifies participation of APRIL signaling in breast cancer promotion; we propose impairment of this pathway as a potential therapeutic strategy.

Tumor-derived exosomes are enriched in ΔNp73, which promotes oncogenic potential in acceptor cells and correlates with patient survival.

Tumor-derived exosomes are emerging as local and systemic cell-to-cell mediators of oncogenic information through the horizontal transfer of mRNAs, microRNAs and proteins during tumorigenesis. The exosomal content has been described as biologically active when taken up by the recipient cell. Identifying the specific molecular cargo of exosomes will help to determine their function in specific steps of the tumorigenic process. Here we evaluate whether ΔNp73 is selectively packaged in tumor-derived exosomes, its function in the acceptor cells in vitro and in vivo and its prognosis potential in cancer. ΔNp73 messenger is enriched in tumor-derived exosomes, suggesting its active sorting in these microvesicles. We observed the transmission of this exosome cargo to different cell types and how it confers proliferation potential and chemoresistance to the acceptor cells in vitro and in animal models. Finally, our data support the potential prognostic value of exosomal ΔNp73 in colon cancer patients.

Novel lambda FRET spectral confocal microscopy imaging method.

We report a highly specific, sensitive, and robust method for analyzing fluorescence resonance energy transfer (FRET) based on spectral laser scanning confocal microscopy imaging. The lambda FRET (lambdaFRET) algorithm comprises imaging of a FRET sample at multiple emission wavelengths rendering a FRET spectrum, which is separated into its donor and acceptor components to obtain a pixel-based calculation of FRET efficiency. The method uses a novel off-line precalibration procedure for spectral bleed-through correction based on the acquisition of reference reflection images, which simplifies the method and reduces variability. LambdaFRET method was validated using structurally characterized FRET standards with variable linker lengths and stoichiometries designed for this purpose. LambdaFRET performed better than other well-established methods, such as acceptor photobleaching and sensitized emission-based methods, in terms of specificity, reproducibility, and sensitivity to distance variations. Moreover, lambdaFRET analysis was unaffected by high fluorochrome spectral overlap and cellular autofluorescence. The lambdaFRET method demonstrated outstanding performance in intra- and intermolecular FRET analysis in both fixed and live cell imaging studies.

MT1-MMP proinvasive activity is regulated by a novel Rab8-dependent exocytic pathway.

MT1-matrix metalloproteinase (MT1-MMP) is one of the most critical factors in the invasion machinery of tumor cells. Subcellular localization to invasive structures is key for MT1-MMP proinvasive activity. However, the mechanism driving this polarized distribution remains obscure. We now report that polarized exocytosis of MT1-MMP occurs during MDA-MB-231 adenocarcinoma cell migration into collagen type I three-dimensional matrices. Polarized trafficking of MT1-MMP is triggered by beta1 integrin-mediated adhesion to collagen, and is required for protease localization at invasive structures. Localization of MT1-MMP within VSV-G/Rab8-positive vesicles, but not in Rab11/Tf/TfRc-positive compartment in invasive cells, suggests the involvement of the exocytic traffic pathway. Furthermore, constitutively active Rab8 mutants induce MT1-MMP exocytic traffic, collagen degradation and invasion, whereas Rab8- but not Rab11-knockdown inhibited these processes. Altogether, these data reveal a novel pathway of MT1-MMP redistribution to invasive structures, exocytic vesicle trafficking, which is crucial for its role in tumor cell invasiveness. Mechanistically, MT1-MMP delivery to invasive structures, and therefore its proinvasive activity, is regulated by Rab8 GTPase.