Trametinib sensitizes KRAS-mutant lung adenocarcinoma tumors to PD-1/PD-L1 axis blockade via Id1 downregulation.

BACKGROUND: The identification of novel therapeutic strategies to overcome resistance to the MEK inhibitor trametinib in mutant KRAS lung adenocarcinoma (LUAD) is a challenge. This study analyzes the effects of trametinib on Id1 protein, a key factor involved in the KRAS oncogenic pathway, and investigates the role of Id1 in the acquired resistance to trametinib as well as the synergistic anticancer effect of trametinib combined with immunotherapy in KRAS-mutant LUAD. METHODS: We evaluated the effects of trametinib on KRAS-mutant LUAD by Western blot, RNA-seq and different syngeneic mouse models. Genetic modulation of Id1 expression was performed in KRAS-mutant LUAD cells by lentiviral or retroviral transductions of specific vectors. Cell viability was assessed by cell proliferation and colony formation assays. PD-L1 expression and apoptosis were measured by flow cytometry. The anti-tumor efficacy of the combined treatment with trametinib and PD-1 blockade was investigated in KRAS-mutant LUAD mouse models, and the effects on the tumor immune infiltrate were analyzed by flow cytometry and immunohistochemistry. RESULTS: We found that trametinib activates the proteasome-ubiquitin system to downregulate Id1 in KRAS-mutant LUAD tumors. Moreover, we found that Id1 plays a major role in the acquired resistance to trametinib treatment in KRAS-mutant LUAD cells. Using two preclinical syngeneic KRAS-mutant LUAD mouse models, we found that trametinib synergizes with PD-1/PD-L1 blockade to hamper lung cancer progression and increase survival. This anti-tumor activity depended on trametinib-mediated Id1 reduction and was associated with a less immunosuppressive tumor microenvironment and increased PD-L1 expression on tumor cells. CONCLUSIONS: Our data demonstrate that Id1 expression is involved in the resistance to trametinib and in the synergistic effect of trametinib with anti-PD-1 therapy in KRAS-mutant LUAD tumors. These findings suggest a potential therapeutic approach for immunotherapy-refractory KRAS-mutant lung cancers.

A novel [89Zr]-anti-PD-1-PET-CT to assess response to PD-1/PD-L1 blockade in lung cancer.

Background: Harnessing the anti-tumor immune system response by targeting the program cell death protein (PD-1) and program cell death ligand protein (PD-L1) axis has been a major breakthrough in non-small cell lung cancer (NSCLC) therapy. Nonetheless, conventional imaging tools cannot accurately assess response in immunotherapy-treated patients. Using a lung cancer syngeneic mouse model responder to immunotherapy, we aimed to demonstrate that [89Zr]-anti-PD-1 immuno-PET is a safe and feasible imaging modality to assess the response to PD-1/PD-L1 blockade in NSCLC. Materials and methods: A syngeneic mouse model responder to anti-PD-1 therapy was used. Tumor growth and response to PD-1 blockade were monitored by conventional 2-deoxy-2-[18F]fluoro-D-glucose ([18F]-FDG) PET scans. Additionally, tumor lymphocyte infiltration was analyzed by the use of an [89Zr]-labeled anti-PD-1 antibody and measured as 89Zr tumor uptake. Results: Conventional [18F]-FDG-PET scans failed to detect the antitumor activity exerted by anti-PD-1 therapy. However, [89Zr]-anti-PD-1 uptake was substantially higher in mice that responded to PD-1 blockade. The analysis of tumor-infiltrating immune cell populations and interleukins demonstrated an increased anti-tumor effect elicited by activation of effector immune cells in PD-1-responder mice. Interestingly, a positive correlation between [89Zr]-anti-PD-1 uptake and the proportion of tumor-infiltrating lymphocytes (TILs) was found (Cor = 0.8; p = 0.001). Conclusion: Our data may support the clinical implementation of immuno-PET as a promising novel imaging tool to predict and assess the response of PD-1/PD-L1 inhibitors in patients with NSCLC.

Presence of Activated (Phosphorylated) STAT3 in Radiation Necrosis Following Stereotactic Radiosurgery for Brain Metastases.

Brain radiation necrosis (RN) is a subacute or late adverse event following radiotherapy, involving an exacerbated inflammatory response of the brain tissue. The risk of symptomatic RN associated with stereotactic radiosurgery (SRS) as part of the treatment of brain metastases (BMs) has been a subject of recent investigation. The activation of the signal transducer and activator of transcription 3 (STAT3) was shown in reactive astrocytes (RA) associated with BMs. Given that the pathophysiological mechanisms behind RN are not fully understood, we sought to investigate the role of STAT3 among other inflammatory markers in RN development. A mouse model of RN using clinical LINAC-based SRS was designed to induce brain necrosis with the administration of 50 Gy in a single fraction to the left hemisphere using a circular collimator of 5 mm diameter. Immunohistochemistry and multiplex staining for CD4, CD8, CD68, GFAP, and STAT3 were performed. For validation, eleven patients with BMs treated with SRS who developed symptomatic RN and required surgery were identified to perform staining for CD68, GFAP, and STAT3. In the mouse model, the RN and perinecrotic areas showed significantly higher staining for F4/80+ and GFAP+ cells, with a high infiltration of CD4 and CD8 T-lymphocytes, when compared to the non-irradiated cerebral hemisphere. A high number of GFAP+pSTAT3+ and F4/80+pSTAT3+ cells was found in the RN areas and the rest of the irradiated hemisphere. The analysis of human brain specimens showed that astrocytes and microglia were actively phosphorylating STAT3 in the areas of RN and gliosis. Phosphorylated STAT3 is highly expressed in the microglia and RA pertaining to the areas of brain RN. Targeting STAT3 via inhibition represents a promising strategy to ameliorate symptomatic RN in BM patients undergoing SRS.

The high-throughput atomization of polymer solutions for fiber synthesis in a single step aided with corona ionizers.

Polymer microfibers are ubiquitous structures across virtually all technological fields. Their applications include, for instance, filter media, tissue regeneration, wound healing and dressing, and reinforcement materials. The most effective methods for fabrication of fibrous micro and nanomaterials rely on electric fields to spin a liquid jet into an ultrafine thread that rapidly dries up forming a fiber. Continuous spinning and collection leads to formation of fiber mats. Here we report a robust yet simple approach for the massive production of liquid threads, which upon acquiring electrical charges in-flight are collected downstream in the form of fibers. The entire process takes place on-line in a single step. The liquid threads are produced through the fragmentation of a polymer solution bulk due to a turbulent interaction of a gas-liquid interface in the interior of an engineered device, a so-called Flow Blurring atomizer. The particularity of this approach consists precisely in such vigorous interaction, at the micrometer scale, which triggers a bubbly motion in the interior of the device, that is a "micro-mixing". Subsequently, the threads are passed through ionized air currents, at ambient conditions, and then stretched to sub-micrometer dimensions by electric fields. Polyvinylpyrrolidone (PVP) as well as carbon nanotubes (CNTs) or graphene oxide sheets (GOSs)-containing PVP fibers, with diameters in the range 100-900 nm, were synthesized via this approach. In the cases studied herein the method was operated at liquid flow rates (i.e. production rates) of 0.2 mL/min but it could be readily increased up to a few tens of mL/min. The method requires further improvement and optimization, nevertheless it is a promising alternative for mass production of polymer fibers.

Estrogen Receptor and Immune Checkpoint Inhibitors: New Partners in Lung Cancer?

The influence of sex on immunotherapy response in patients with non-small cell lung cancer (NSCLC) had been studied with no clear conclusions. An article in this issue reports that a key determinant of response is not sex but the existence of a 17ß-estradiol/ERα/PDL1 signaling loop in NSCLC. This intriguing result opens new therapeutic options. See related article by Anobile et al., p. 3958.

Integrating a micro-mixing mechanism and on-line thermal processing for the large-scale ejection of polymeric liquid threads for producing ultrafine fibers.

Micro/nanofibers are structures that nowadays have a wide range of cutting-edge applications including energy generation and storage devices, smart textiles, cell growth, and tissue engineering. These fibrous materials are mostly produced from polymer solutions spun, under laminar flow conditions, into nanofibers by external forces. However, the turbulent interaction of gas-liquid interfaces offers an innovative approach for the high-throughput production of nanofibers. Here, we present Flow Blurring (FB), a solely pneumatic approach for the massive production of liquid threads of polymer solutions, which relies on a micro-mixing mechanism that triggers a turbulent motion capable of fragmenting a viscous flow. The as-ejected threads are subsequently processed thermally, on-line in a single-step, thus producing micro/nanofibers that form mats. The method operates with relatively large liquid flow rates, equivalent of a high production rate, and is thus suitable for industrial production of engineered nanomaterials. In this work, we used solutions of poly(vinyl alcohol) (PVA) to study its ejection and fragmentation dynamics through computational fluid dynamics (CFD) simulations. In addition, the physics underlying the regulation of the liquid flow rate in FB atomizers are proposed. Fibers with typical diameters in the range 400-800 nm were produced by online heating of the liquid threads. Liquid ejection experiments were performed under different operating conditions thus verifying the capability of the method for synthesizing submicrometer-sized fibers with high uniformity and production rates suitable for scaling up.

Cancer Cell-Intrinsic Alterations Associated with an Immunosuppressive Tumor Microenvironment and Resistance to Immunotherapy in Lung Cancer.

Despite the great clinical success of immunotherapy in lung cancer patients, only a small percentage of them (<40%) will benefit from this therapy alone or combined with other strategies. Cancer cell-intrinsic and cell-extrinsic mechanisms have been associated with a lack of response to immunotherapy. The present study is focused on cancer cell-intrinsic genetic, epigenetic, transcriptomic and metabolic alterations that reshape the tumor microenvironment (TME) and determine response or refractoriness to immune checkpoint inhibitors (ICIs). Mutations in KRAS, SKT11(LKB1), KEAP1 and TP53 and co-mutations of these genes are the main determinants of ICI response in non-small-cell lung cancer (NSCLC) patients. Recent insights into metabolic changes in cancer cells that impose restrictions on cytotoxic T cells and the efficacy of ICIs indicate that targeting such metabolic restrictions may favor therapeutic responses. Other emerging pathways for therapeutic interventions include epigenetic modulators and DNA damage repair (DDR) pathways, especially in small-cell lung cancer (SCLC). Therefore, the many potential pathways for enhancing the effect of ICIs suggest that, in a few years, we will have much more personalized medicine for lung cancer patients treated with immunotherapy. Such strategies could include vaccines and chimeric antigen receptor (CAR) cells.

PTEN Loss Confers Resistance to Anti-PD-1 Therapy in Non-Small Cell Lung Cancer by Increasing Tumor Infiltration of Regulatory T Cells.

Immunotherapy resistance in non-small cell lung cancer (NSCLC) may be mediated by an immunosuppressive microenvironment, which can be shaped by the mutational landscape of the tumor. Here, we observed genetic alterations in the PTEN/PI3K/AKT/mTOR pathway and/or loss of PTEN expression in >25% of patients with NSCLC, with higher frequency in lung squamous carcinomas (LUSC). Patients with PTEN-low tumors had higher levels of PD-L1 and PD-L2 and showed worse progression-free survival when treated with immunotherapy. Development of a Pten-null LUSC mouse model revealed that tumors with PTEN loss were refractory to antiprogrammed cell death protein 1 (anti-PD-1), highly metastatic and fibrotic, and secreted TGFß/CXCL10 to promote conversion of CD4+ lymphocytes into regulatory T cells (Treg). Human and mouse PTEN-low tumors were enriched in Tregs and expressed higher levels of immunosuppressive genes. Importantly, treatment of mice bearing Pten-null tumors with TLR agonists and anti-TGFß antibody aimed to alter this immunosuppressive microenvironment and led to tumor rejection and immunologic memory in 100% of mice. These results demonstrate that lack of PTEN causes immunotherapy resistance in LUSCs by establishing an immunosuppressive tumor microenvironment that can be reversed therapeutically. SIGNIFICANCE: PTEN loss leads to the development of an immunosuppressive microenvironment in lung cancer that confers resistance to anti-PD-1 therapy, which can be overcome by targeting PTEN loss-mediated immunosuppression.

Targeted siRNA lipid nanoparticles for the treatment of KRAS-mutant tumors.

K-RAS is a highly relevant oncogene that is mutated in approximately 90% of pancreatic cancers and 20-25% of lung adenocarcinomas. The aim of this work was to develop a new anti-KRAS siRNA therapeutic strategy through the engineering of functionalized lipid nanoparticles (LNPs). To do this, first, a potent pan anti-KRAS siRNA sequence was chosen from the literature and different chemical modifications of siRNA were tested for their transfection efficacy (KRAS knockdown) and anti-proliferative effects on various cancer cell lines. Second, a selected siRNA candidate was loaded into tLyp-1 targeted and non-targeted lipid nanoparticles (LNPs). The biodistribution and antitumoral efficacy of selected siRNA-loaded LNP-prototypes were evaluated in vivo using a pancreatic cancer murine model (subcutaneous xenograft CFPAC-1 tumors). Our results show that tLyp-1-tagged targeted LNPs have an enhanced accumulation in the tumor compared to non-targeted LNPs. Moreover, a significant reduction in the pancreatic tumor growth was observed when the anti-KRAS siRNA treatment was combined with a classical chemotherapeutic agent, gemcitabine. In conclusion, our work demonstrates the benefits of using a targeting approach to improve tumor accumulation of siRNA-LNPs and its positive impact on tumor reduction.

An experimental study of liquid micro-jets produced with a gas dynamic virtual nozzle under the influence of an electric field.

The results of an experimental study of micro-jets produced with a gas dynamic virtual nozzle (GDVN) under the influence of an electric field are provided and discussed for the first time. The experimental study is performed with a 50% volume mixture of water and ethanol, and nitrogen focusing gas. The liquid sample and gas Reynolds numbers range from 0.09-5.4 and 0-190, respectively. The external electrode was positioned 400-500 µm downstream of the nozzle tip and an effect of electric potential between the electrode and the sample liquid from 0-7 kV was investigated. The jetting parametric space is examined as a function of operating gas and liquid flow rates, outlet chamber pressure, and an external electric field. The experimentally observed jet diameter, length and velocity ranged from 1-25 µm, 50-500 µm and 0.5-10 m/s, respectively. The jetting shape snapshots were processed automatically using purposely developed computer vision software. The velocity of the jet was calculated from the measured jet diameter and the sample flow rate. It is found that micro-jets accelerate in the direction of the applied electric field in the downstream direction at a constant acceleration as opposed to the standard GDVNs. New jetting modes were observed, where either the focusing gas or the electric forces dominate, encouraging further theoretical and numerical studies towards optimized system design. The study shows the potential to unlock a new generation of low background sample delivery for serial diffraction measurements of weakly scattering objects.

Evaluation of trefoil factor 3 as a non-invasive biomarker of gastric intestinal metaplasia and gastric cancer in a high-risk population.

BACKGROUND: Adenocarcinoma is preceded by chronic atrophic gastritis, gastric intestinal metaplasia and dysplasia. Trefoil factor 3 (TFF3) is a peptide secreted by goblet cells, which is abundantly present in intestinal metaplasia. AIM: To evaluate the utility of serum TFF3 as a non-invasive biomarker for the diagnosis of intestinal metaplasia and gastric cancer. METHODS: Single-center, cross-sectional study of 274 patients who consecutively underwent upper gastrointestinal endoscopy with gastric biopsies (updated Sydney system). TFF3 levels were measured in serum by a commercial ELISA kit. Patients with normal histology or chronic atrophic gastritis without intestinal metaplasia comprised the control group. In addition, 14 patients with invasive gastric cancer were included as a reference group. The association between TFF3 levels and intestinal metaplasia was assessed by logistic regression. RESULTS: Patients with intestinal metaplasia (n=110) had a higher median TFF3 level as compared to controls (n=164), 13.1 vs. 11.9ng/mL, respectively (p=0.024). Multivariable logistic regression showed a no significant association between TFF3 levels and intestinal metaplasia (OR=1.20; 95%CI: 0.87-1.65; p-trend=0.273). The gastric cancer group had a median TFF3 level of 20.5ng/mL, and a significant association was found (OR=3.26; 95%CI: 1.29-8.27; p-trend=0.013). CONCLUSION: Serum levels of TFF3 do not discriminate intestinal metaplasia in this high-risk Latin American population. Nevertheless, we confirmed an association between TFF3 levels and invasive gastric cancer.

In Vivo Analysis of Tumor-Associated Macrophages in the Tumor Microenvironment.

In most solid cancers, tumor-associated macrophages (TAMs) infiltrating the tumor microenvironment (TME) represent a major population of immunosuppressive cells. This correlates with poor prognosis and resistance to antitumoral therapies, including immune checkpoint inhibitors. Although initial preclinical studies were primarily meant to deplete macrophages in the TME or prevent their recruitment at tumor sites, recent evidence has indicated that the reprogramming of macrophages into cytotoxic effectors might be more beneficial in eliciting an effective antitumor immune response. Taking this into consideration, the comprehensive analysis of the phenotype and function of macrophages in the TME, and their interaction with cancer cells or other immune cells, has become of paramount importance in oncological research. Accordingly, here we explain the experimental procedures for the in vivo evaluation of tumor progression and response to therapy, with a particular focus on the detailed analysis of TAMs and related immune cells in the TME by flow cytometry, RNA analysis, and multiplex immunophenotyping. The output generated through these experiments allow researchers to test the efficacy of new therapeutic strategies on targeting.

Polymeric nanocapsules loaded with poly(I:C) and resiquimod to reprogram tumor-associated macrophages for the treatment of solid tumors.

Background: In the tumor microenvironment (TME), tumor-associated macrophages (TAMs) play a key immunosuppressive role that limits the ability of the immune system to fight cancer. Toll-like receptors (TLRs) ligands, such as poly(I:C) or resiquimod (R848) are able to reprogram TAMs towards M1-like antitumor effector cells. The objective of our work has been to develop and evaluate polymeric nanocapsules (NCs) loaded with poly(I:C)+R848, to improve drug stability and systemic toxicity, and evaluate their targeting and therapeutic activity towards TAMs in the TME of solid tumors. Methods: NCs were developed by the solvent displacement and layer-by-layer methodologies and characterized by dynamic light scattering and nanoparticle tracking analysis. Hyaluronic acid (HA) was chemically functionalized with mannose for the coating of the NCs to target TAMs. NCs loaded with TLR ligands were evaluated in vitro for toxicity and immunostimulatory activity by Alamar Blue, ELISA and flow cytometry, using primary human monocyte-derived macrophages. For in vivo experiments, the CMT167 lung cancer model and the MN/MCA1 fibrosarcoma model metastasizing to lungs were used; tumor-infiltrating leukocytes were evaluated by flow cytometry and multispectral immunophenotyping. Results: We have developed polymeric NCs loaded with poly(I:C)+R848. Among a series of 5 lead prototypes, protamine-NCs were selected based on their physicochemical properties (size, charge, stability) and in vitro characterization, showing good biocompatibility on primary macrophages and ability to stimulate their production of T-cell attracting chemokines (CXCL10, CCL5) and to induce M1-like macrophages cytotoxicity towards tumor cells. In mouse tumor models, the intratumoral injection of poly(I:C)+R848-protamine-NCs significantly prevented tumor growth and lung metastasis. In an orthotopic murine lung cancer model, the intravenous administration of poly(I:C)+R848-prot-NCs, coated with an additional layer of HA-mannose to improve TAM-targeting, resulted in good antitumoral efficacy with no apparent systemic toxicity. While no significant alterations were observed in T cell numbers (CD8, CD4 or Treg), TAM-reprogramming in treated mice was confirmed by the relative decrease of interstitial versus alveolar macrophages, having higher CD86 expression but lower CD206 and Arg1 expression in the same cells, in treated mice. Conclusion: Mannose-HA-protamine-NCs loaded with poly(I:C)+R848 successfully reprogram TAMs in vivo, and reduce tumor progression and metastasis spread in mouse tumors.

Massive production of fibroin nano-fibrous biomaterial by turbulent co-flow.

Among the different polymers (proteins, polysaccharides, etc.) that make up natural fibers, fibroin is a protein produced by silk spinning animals, which have developed an optimized system for the conversion of a highly concentrated solution of this protein into high-performance solid fibers. This protein undergoes a self-assembly process in the silk glands that result from chemical gradients and by the application of mechanical stresses during the last step of the process. In the quest for a process that could mimic natural spinning at massive scales, we have discovered that turbulence offers a novel and promising solution: a turbulent liquid jet can be formed by a chemically green and simple coagulating liquid (a diluted solution of acetic acid in etanol) co-flowing with a concentrated solution of fibroin in water by the use of a Flow Blurring nebulizer. In this system, (a) the co-flowing coagulant liquid extracts water from the original protein solution and, simultaneously, (b) the self-assembled proteins are subjected to mechanical actions, including splitting and stretching. Given the non-negligible produced content with the size and appearance of natural silk, the stochastic distribution of those effects in our process should contain the range of natural ones found in animals. The resulting easily functionalizable and tunable one-step material is 100% biocompatible, and our method a perfect candidate to large-scale, low-cost, green and sustainable processing of fibroin for fibres and textiles.

IL-6/STAT3 signaling in tumor cells restricts the expression of frameshift-derived neoantigens by SMG1 induction.

BACKGROUND: The quality and quantity of tumor neoantigens derived from tumor mutations determines the fate of the immune response in cancer. Frameshift mutations elicit better tumor neoantigens, especially when they are not targeted by nonsense-mediated mRNA decay (NMD). For tumor progression, malignant cells need to counteract the immune response including the silencing of immunodominant neoantigens (antigen immunoediting) and promoting an immunosuppressive tumor microenvironment. Although NMD inhibition has been reported to induce tumor immunity and increase the expression of cryptic neoantigens, the possibility that NMD activity could be modulated by immune forces operating in the tumor microenvironment as a new immunoediting mechanism has not been addressed. METHODS: We study the effect of SMG1 expression (main kinase that initiates NMD) in the survival and the nature of the tumor immune infiltration using TCGA RNAseq and scRNAseq datasets of breast, lung and pancreatic cancer. Different murine tumor models were used to corroborate the antitumor immune dependencies of NMD. We evaluate whether changes of SMG1 expression in malignant cells impact the immune response elicited by cancer immunotherapy. To determine how NMD fluctuates in malignant cells we generated a luciferase reporter system to track NMD activity in vivo under different immune conditions. Cytokine screening, in silico studies and functional assays were conducted to determine the regulation of SMG1 via IL-6/STAT3 signaling. RESULTS: IL-6/STAT3 signaling induces SMG1, which limits the expression of potent frameshift neoantigens that are under NMD control compromising the outcome of the immune response. CONCLUSION: We revealed a new neoantigen immunoediting mechanism regulated by immune forces (IL-6/STAT3 signaling) responsible for silencing otherwise potent frameshift mutation-derived neoantigens.

Tumor-Intrinsic Nuclear ß-Catenin Associates with an Immune Ignorance Phenotype and a Poorer Prognosis in Head and Neck Squamous Cell Carcinomas.

Activation of WNT/ß-catenin signaling has been associated with a non-T-cell-inflamed tumor microenvironment (TME) in several cancers. The aim of this work was to investigate the relationship between ß-catenin signaling and TME inflammation in head and neck squamous cell carcinomas (HNSCCs). Membrane and nuclear ß-catenin expression, PD-L1 expression, and CD8+ tumor-infiltrating lymphocyte (TIL) density were jointly evaluated by immunohistochemistry in a series of 372 HPV-negative HNSCCs. Membrane ß-catenin levels decreased in carcinomas compared to the normal epithelium. Positive nuclear ß-catenin was detected in 50 tumors (14.3%) and was significantly associated with a low CD8+ TIL density (168 cells/mm2 versus 293 cells/mm2 in nuclear-ß-catenin-negative cases; p = 0.01) and a tendency for a lower expression of PD-L1, resulting in association with a noninflamed TME (i.e., type II, immunological ignorance). Multivariate Cox analysis further demonstrated that low infiltration by CD8+ TILs (HR = 1.6, 95% CI = 1.19-2.14, p = 0.002) and nuclear ß-catenin expression (HR = 1.47, 95% CI = 1.01-2.16, p = 0.04) were both independently associated with a poorer disease-specific survival. In conclusion, tumor-intrinsic nuclear ß-catenin activation is associated with a non-inflamed TME phenotype and a poorer prognosis, thereby suggesting a possible implication as an immune exclusion mechanism for a subset of HNSCC patients.

Translation of a tissue epigenetic signature to circulating free DNA suggests BCAT1 as a potential noninvasive diagnostic biomarker for lung cancer.

Lung cancer patients are diagnosed at late stages when curative treatments are no longer possible; thus, molecular biomarkers for noninvasive detection are urgently needed. In this sense, we previously identified and validated an epigenetic 4-gene signature that yielded a high diagnostic performance in tissue and invasive pulmonary fluids. We analyzed DNA methylation levels using the ultrasensitive digital droplet PCR in noninvasive samples in a cohort of 83 patients. We demonstrated that BCAT1 is the candidate that achieves high diagnostic efficacy in circulating DNA derived from plasma (area under the curve: 0.85). Impact of potentially confounding variables was also explored.

DSTYK inhibition increases the sensitivity of lung cancer cells to T cell-mediated cytotoxicity.

Lung cancer remains the leading cause of cancer-related death worldwide. We identify DSTYK, a dual serine/threonine and tyrosine non-receptor protein kinase, as a novel actionable target altered in non-small cell lung cancer (NSCLC). We also show DSTYK's association with a lower overall survival (OS) and poorer progression-free survival (PFS) in multiple patient cohorts. Abrogation of DSTYK in lung cancer experimental systems prevents mTOR-dependent cytoprotective autophagy, impairs lysosomal biogenesis and maturation, and induces accumulation of autophagosomes. Moreover, DSTYK inhibition severely affects mitochondrial fitness. We demonstrate in vivo that inhibition of DSTYK sensitizes lung cancer cells to TNF-α-mediated CD8+-killing and immune-resistant lung tumors to anti-PD-1 treatment. Finally, in a series of lung cancer patients, DSTYK copy number gain predicts lack of response to the immunotherapy. In summary, we have uncovered DSTYK as new therapeutic target in lung cancer. Prioritization of this novel target for drug development and clinical testing may expand the percentage of NSCLC patients benefiting from immune-based treatments.

YES1 Is a Druggable Oncogenic Target in SCLC.

INTRODUCTION: SCLC is an extremely aggressive subtype of lung cancer without approved targeted therapies. Here we identified YES1 as a novel targetable oncogene driving SCLC maintenance and metastasis. METHODS: Association between YES1 levels and prognosis was evaluated in SCLC clinical samples. In vitro functional experiments for proliferation, apoptosis, cell cycle, and cytotoxicity were performed. Genetic and pharmacologic inhibition of YES1 was evaluated in vivo in cell- and patient-derived xenografts and metastasis. YES1 levels were evaluated in mouse and patient plasma-derived exosomes. RESULTS: Overexpression or gain/amplification of YES1 was identified in 31% and 26% of cases, respectively, across molecular subgroups, and was found as an independent predictor of poor prognosis. Genetic depletion of YES1 dramatically reduced cell proliferation, three-dimensional organoid formation, tumor growth, and distant metastasis, leading to extensive apoptosis and tumor regressions. Mechanistically, YES1-inhibited cells revealed alterations in the replisome and DNA repair processes, that conferred sensitivity to irradiation. Pharmacologic blockade with the novel YES1 inhibitor CH6953755 or dasatinib induced marked antitumor activity in organoid models and cell- and patient-derived xenografts. YES1 protein was detected in plasma exosomes from patients and mouse models, with levels matching those of tumors, suggesting that circulating YES1 could represent a biomarker for patient selection/monitoring. CONCLUSIONS: Our results provide evidence that YES1 is a new druggable oncogenic target and biomarker to advance the clinical management of a subpopulation of patients with SCLC.