Enhancing NSCLC recurrence prediction with PET/CT habitat imaging, ctDNA, and integrative radiogenomics-blood insights.

While we recognize the prognostic importance of clinicopathological measures and circulating tumor DNA (ctDNA), the independent contribution of quantitative image markers to prognosis in non-small cell lung cancer (NSCLC) remains underexplored. In our multi-institutional study of 394 NSCLC patients, we utilize pre-treatment computed tomography (CT) and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) to establish a habitat imaging framework for assessing regional heterogeneity within individual tumors. This framework identifies three PET/CT subtypes, which maintain prognostic value after adjusting for clinicopathologic risk factors including tumor volume. Additionally, these subtypes complement ctDNA in predicting disease recurrence. Radiogenomics analysis unveil the molecular underpinnings of these imaging subtypes, highlighting downregulation in interferon alpha and gamma pathways in the high-risk subtype. In summary, our study demonstrates that these habitat imaging subtypes effectively stratify NSCLC patients based on their risk levels for disease recurrence after initial curative surgery or radiotherapy, providing valuable insights for personalized treatment approaches.

Distinct patterns of auto-reactive antibodies associated with organ-specific immune-related adverse events.

The roles of preexisting auto-reactive antibodies in immune-related adverse events (irAEs) associated with immune checkpoint inhibitor therapy are not well defined. Here, we analyzed plasma samples longitudinally collected at predefined time points and at the time of irAEs from 58 patients with immunotherapy naïve metastatic non-small cell lung cancer treated on clinical protocol with ipilimumab and nivolumab. We used a proteomic microarray system capable of assaying antibody reactivity for IgG and IgM fractions against 120 antigens for systemically evaluating the correlations between auto-reactive antibodies and certain organ-specific irAEs. We found that distinct patterns of auto-reactive antibodies at baseline were associated with the subsequent development of organ-specific irAEs. Notably, ACHRG IgM was associated with pneumonitis, anti-cytokeratin 19 IgM with dermatitis, and anti-thyroglobulin IgG with hepatitis. These antibodies merit further investigation as potential biomarkers for identifying high-risk populations for irAEs and/or monitoring irAEs during immunotherapy treatment. Trial registration: ClinicalTrials.gov identifier: NCT03391869.

EMT activates exocytotic Rabs to coordinate invasion and immunosuppression in lung cancer.

Epithelial-to-mesenchymal transition (EMT) underlies immunosuppression, drug resistance, and metastasis in epithelial malignancies. However, the way in which EMT orchestrates disparate biological processes remains unclear. Here, we identify an EMT-activated vesicular trafficking network that coordinates promigratory focal adhesion dynamics with an immunosuppressive secretory program in lung adenocarcinoma (LUAD). The EMT-activating transcription factor ZEB1 drives exocytotic vesicular trafficking by relieving Rab6A, Rab8A, and guanine nucleotide exchange factors from miR-148a-dependent silencing, thereby facilitating MMP14-dependent focal adhesion turnover in LUAD cells and autotaxin-mediated CD8+ T cell exhaustion, indicating that cell-intrinsic and extrinsic processes are linked through a microRNA that coordinates vesicular trafficking networks. Blockade of ZEB1-dependent secretion reactivates antitumor immunity and negates resistance to PD-L1 immune checkpoint blockade, an important clinical problem in LUAD. Thus, EMT activates exocytotic Rabs to drive a secretory program that promotes invasion and immunosuppression in LUAD.

A phase I trial of the pan-ERBB inhibitor neratinib combined with the MEK inhibitor trametinib in patients with advanced cancer with EGFR mutation/amplification, HER2 mutation/amplification, HER3/4 mutation or KRAS mutation.

PURPOSE: Aberrant alterations of ERBB receptor tyrosine kinases lead to tumorigenesis. Single agent therapy targeting EGFR or HER2 has shown clinical successes, but drug resistance often develops due to aberrant or compensatory mechanisms. Herein, we sought to determine the feasibility and safety of neratinib and trametinib in patients with EGFR mutation/amplification, HER2 mutation/amplification, HER3/4 mutation and KRAS mutation. METHODS: Patients with actionable somatic mutations or amplifications in ERBB genes or actionable KRAS mutations were enrolled to receive neratinib and trametinib in this phase I dose escalation trial. The primary endpoint was determination of the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT). Secondary endpoints included pharmacokinetic analysis and preliminary anti-tumor efficacy. RESULTS: Twenty patients were enrolled with a median age of 50.5 years and a median of 3 lines of prior therapy. Grade 3 treatment-related toxicities included: diarrhea (25%), vomiting (10%), nausea (5%), fatigue (5%) and malaise (5%). The MTD was dose level (DL) minus 1 (neratinib 160 mg daily with trametinib 1 mg, 5 days on and 2 days off) given 2 DLTs of grade 3 diarrhea in DL1 (neratinib 160 mg daily with trametinib 1 mg daily). The treatment-related toxicities of DL1 included: diarrhea (100%), nausea (55.6%) and rash (55.6%). Pharmacokinetic data showed trametinib clearance was significantly reduced leading to high drug exposures of trametinib. Two patients achieved stable disease (SD) ≥ 4 months. CONCLUSION: Neratinib and trametinib combination was toxic and had limited clinical efficacy. This may be due to suboptimal drug dosing given drug-drug interactions. TRIAL REGISTRATION ID: NCT03065387.

IL6 Mediates Suppression of T- and NK-cell Function in EMT-associated TKI-resistant EGFR-mutant NSCLC.

PURPOSE: Patients with advanced non-small cell lung cancer (NSCLC) harboring activating EGFR mutations are initially responsive to tyrosine kinase inhibitors (TKI). However, therapeutic resistance eventually emerges, often via secondary EGFR mutations or EGFR-independent mechanisms such as epithelial-to-mesenchymal transition. Treatment options after EGFR-TKI resistance are limited as anti-PD-1/PD-L1 inhibitors typically display minimal benefit. Given that IL6 is associated with worse outcomes in patients with NSCLC, we investigate whether IL6 in part contributes to this immunosuppressed phenotype. EXPERIMENTAL DESIGN: We utilized a syngeneic genetically engineered mouse model (GEMM) of EGFR-mutant NSCLC to investigate the effects of IL6 on the tumor microenvironment and the combined efficacy of IL6 inhibition and anti-PD-1 therapy. Corresponding in vitro studies used EGFR-mutant human cell lines and clinical specimens. RESULTS: We identified that EGFR-mutant tumors which have oncogene-independent acquired resistance to EGFR-TKIs were more mesenchymal and had markedly enhanced IL6 secretion. In EGFR-mutant GEMMs, IL6 depletion enhanced activation of infiltrating natural killer (NK)- and T-cell subpopulations and decreased immunosuppressive regulatory T and Th17 cell populations. Inhibition of IL6 increased NK- and T cell-mediated killing of human osimertinib-resistant EGFR-mutant NSCLC tumor cells in cell culture. IL6 blockade sensitized EGFR-mutant GEMM tumors to PD-1 inhibitors through an increase in tumor-infiltrating IFNγ+ CD8+ T cells. CONCLUSIONS: These data indicate that IL6 is upregulated in EGFR-mutant NSCLC tumors with acquired EGFR-TKI resistance and suppressed T- and NK-cell function. IL6 blockade enhanced antitumor immunity and efficacy of anti-PD-1 therapy warranting future clinical combinatorial investigations.

Inhibition of the Phosphatidylinositol-3 Kinase Pathway Using Bimiralisib in Loss-of-Function NOTCH1-Mutant Head and Neck Cancer.

BACKGROUND: PI3K/mTOR inhibition leads to apoptosis of NOTCH1-mutant head and neck squamous cell carcinoma (HNSCC) cells. We tested the efficacy of the PI3K/mTOR inhibitor bimiralisib in patients with NOTCH1-mutant HNSCC. METHODS: Patients with recurrent/metastatic NOTCH1-mutant HNSCC who had progressed during chemotherapy and immunotherapy received bimiralisib until unacceptable toxicity or progression. To assess whether NOTCH1 mutations can be detected in blood, we measured circulating tumor DNA (ctDNA). To assess activated NOTCH1 protein levels, we quantitated cleaved NOTCH1 (cl-NOTCH) by immunohistochemistry. RESULTS: Eight patients were treated, and 6 were evaluable for response. The objective response rate was 17%. For all 8 patients, median progression-free and overall survival was 5 and 7 months, respectively. Bimiralisib was well tolerated, with expected hyperglycemia. Pharmacokinetic values were consistent with published studies. NOTCH1 mutations were detected in 83.3% of ctDNA. Staining for tumor cl-NOTCH1 was negative. The trial closed early due to sponsor insolvency. CONCLUSION: Although the trial was small, outcomes with bimiralisib were better than the historical standard of care; Results will need to be confirmed in a larger trial. The lack of cl-NOTCH1 was consistent with loss-of-function mutations and validated our mutation function algorithm. The ability to detect NOTCH1 mutations in blood will help future studies. (ClinicalTrials.gov Identifier: NCT03740100).

Surgical approach does not influence changes in circulating immune cell populations following lung cancer resection.

INTRODUCTION: The multimodal management of operable non-small cell lung cancer (NSCLC) continues to evolve rapidly. The immune milieu allowing for immunotherapeutic benefit can be affected by multiple parameters including clinicopathologic and genetic. Surgery induced physiological changes has received attention for modulating and affecting post-operative oncotaxis and immunosuppression. Here, we sought to investigate how surgical stress influences phenotype of peripheral blood mononuclear cells (PBMCs) in patients with NSCLC who underwent lobectomy. METHODS: Blood was prospectively collected from patients with Stage IA-IIIA NSCLC undergoing lung resection between 2016 and 2018. Samples were obtained pre-operatively, 24 h and 4 weeks after surgery. PBMCs were isolated and subject to high-dimensional flow cytometry, analyzing a total of 115 cell populations with a focus on myeloid cells, T cell activation, and T cell trafficking. We further evaluated how surgical approach influenced post-operative PBMC changes, whether the operation was conducted in an open fashion with thoracotomy, or with minimally invasive Video Assisted Thoracoscopic Surgery (VATS). RESULTS: A total of 76 patients met the inclusion criteria (Open n = 55, VATS n = 21). Surgical resection coincided with a decrease in T lymphocyte populations, including total CD3+ T cells, CD8+ T cells, and T effector memory cells, as well as an increase in monocytic myeloid-derived suppressor cells (mMDSC). Post-operative changes in PBMC populations were resolved after 4 weeks. Surgical-induced changes in immune populations were equivalent in patients undergoing open thoracotomy and VATS. DISCUSSION: Surgical stress resulted in transient reduction in T cells and T effector memory cells, and increase of mMDSC following resection in NSCLC patients. The immune profile modulation was similar regardless of surgical approach. These findings suggest that surgical approach does not seem to affect mononuclear cell lines obtained from peripheral blood. Thus, the decision regarding surgical approach should be patient centered, rather than based on post-operative treatment response optimization.

Clinical Outcomes in Non-Small-Cell Lung Cancer Patients Treated With EGFR-Tyrosine Kinase Inhibitors and Other Targeted Therapies Based on Tumor Versus Plasma Genomic Profiling.

PURPOSE: To compare clinical outcomes in a cohort of patients with advanced non-small-cell lung cancer (NSCLC) with targetable genomic alterations detected using plasma-based circulating tumor DNA (ctDNA) or tumor-based next-generation sequencing (NGS) assays treated with US Food and Drug Administration-approved therapies at a large academic research cancer center. METHODS: A retrospective review from our MD Anderson GEMINI database identified 2,224 blood samples sent for ctDNA NGS testing from 1971 consecutive patients with a diagnosis of advanced NSCLC. Clinical, treatment, and outcome information were collected, reviewed, and analyzed. RESULTS: Overall, 27% of the ctDNA tests identified at least one targetable mutation and 73% of targetable mutations were EGFR-sensitizing mutations. Among patients treated with first-line epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) therapies, there were no significant differences in progression-free survival of 379 days and 352 days (P value = .41) with treatment based on tissue (n = 40) or ctDNA (n = 40), respectively. Additionally, there were no differences in progression-free survival or objective response rate among those with low (n = 8, 0.01%-0.99%) versus high (n = 16, ≥ 1%) levels of ctDNA of the targetable mutation as measured by variant allele frequency (VAF). Overall, there was excellent testing concordance (n = 217 tests) of > 97%, sensitivity of 91.7%, and specificity of 99.7% between blood-based ctDNA NGS and tissue-based NGS assays. CONCLUSION: There were no significant differences in clinical outcomes among patients treated with approved EGFR-TKIs whose mutations were identified using either tumor- or plasma-based comprehensive profiling and those with very low VAF as compared with high VAF, supporting the use of plasma-based profiling to guide initial TKI use in patients with metastatic EGFR-mutant NSCLC.

Neoadjuvant nivolumab or nivolumab plus ipilimumab in operable non-small cell lung cancer: the phase 2 randomized NEOSTAR trial.

Ipilimumab improves clinical outcomes when combined with nivolumab in metastatic non-small cell lung cancer (NSCLC), but its efficacy and impact on the immune microenvironment in operable NSCLC remain unclear. We report the results of the phase 2 randomized NEOSTAR trial (NCT03158129) of neoadjuvant nivolumab or nivolumab + ipilimumab followed by surgery in 44 patients with operable NSCLC, using major pathologic response (MPR) as the primary endpoint. The MPR rate for each treatment arm was tested against historical controls of neoadjuvant chemotherapy. The nivolumab + ipilimumab arm met the prespecified primary endpoint threshold of 6 MPRs in 21 patients, achieving a 38% MPR rate (8/21). We observed a 22% MPR rate (5/23) in the nivolumab arm. In 37 patients resected on trial, nivolumab and nivolumab + ipilimumab produced MPR rates of 24% (5/21) and 50% (8/16), respectively. Compared with nivolumab, nivolumab + ipilimumab resulted in higher pathologic complete response rates (10% versus 38%), less viable tumor (median 50% versus 9%), and greater frequencies of effector, tissue-resident memory and effector memory T cells. Increased abundance of gut Ruminococcus and Akkermansia spp. was associated with MPR to dual therapy. Our data indicate that neoadjuvant nivolumab + ipilimumab-based therapy enhances pathologic responses, tumor immune infiltrates and immunologic memory, and merits further investigation in operable NSCLC.

Genotype-Specific Differences in Circulating Tumor DNA Levels in Advanced NSCLC.

INTRODUCTION: Plasma-based circulating tumor DNA (ctDNA) is an established biomarker for molecular profiling with emerging applications in disease monitoring in multiple tumor types, including, NSCLC. However, determinants of ctDNA shedding and correlation with tumor burden are incompletely understood, particularly in advanced-stage disease. METHODS: We retrospectively analyzed ctDNA-based and tissue-based genomic data and imaging from 144 patients with NSCLC. Tumor burden was quantified with computed tomography (CT) and brain magnetic resonance imaging for the overall cohort and 18F-fludeoxyglucose positron emission tomography-CT in a subset of patients. RESULTS: There was a moderate but statistically significant correlation between ctDNA variant allele frequency and multiple imaging measures of tumor burden such as CT volume (rho = 0.34, p ≤ 0.0001) and metabolic tumor volume (rho = 0.36, p = 0.003). This correlation was strongest in KRAS-mutant tumors (rho = 0.56, p ≤ 0.001), followed by TP53 mutants (rho = 0.43, p ≤ 0.0001), and weakest in EGFR-mutated (EGFR+) tumors (rho = 0.24, p = 0.077). EGFR+ tumors with EGFR copy number gain had significantly higher variant allele frequency than EGFR+ without copy number gain (p ≤ 0.00001). In multivariable analysis, TP53 and EGFR mutations, visceral metastasis, and tumor burden were independent predictors of increased ctDNA shedding. CONCLUSIONS: Levels of detectable ctDNA were affected not only by tumor burden but also by tumor genotype. The genotype-specific differences observed may be due to variations in DNA shedding and cellular turnover. These findings have implications for the emerging use of ctDNA in NSCLC disease monitoring and early detection.

Evolution of Genomic and T-cell Repertoire Heterogeneity of Malignant Pleural Mesothelioma Under Dasatinib Treatment.

PURPOSE: Malignant pleural mesothelioma (MPM) is considered an orphan disease with few treatment options. Despite multimodality therapy, the majority of MPMs recur and eventually become refractory to any systemic treatment. One potential mechanism underlying therapeutic resistance may be intratumor heterogeneity (ITH), making MPM challenging to eradicate. However, the ITH architecture of MPM and its clinical impact have not been well studied. EXPERIMENTAL DESIGN: We delineated the immunogenomic ITH by multiregion whole-exome sequencing and T-cell receptor (TCR) sequencing of 69 longitudinal MPM specimens from nine patients with resectable MPM, who were treated with dasatinib. RESULTS: The median total mutation burden before dasatinib treatment was 0.65/Mb, similar with that of post-dasatinib treatment (0.62/Mb). The median proportion of mutations shared by any given pair of two tumor regions within the same tumors was 80% prior to and 83% post-dasatinib treatment indicating a relatively homogenous genomic landscape. T-cell clonality, a parameter indicating T-cell expansion and reactivity, was significantly increased in tumors after dasatinib treatment. Furthermore, on average, 82% of T-cell clones were restricted to individual tumor regions, with merely 6% of T-cell clones shared by all regions from the same tumors indicating profound TCR heterogeneity. Interestingly, patients with higher T-cell clonality and higher portion of T cells present across all tumor regions in post-dasatinib-treated tumors had significantly longer survival. CONCLUSIONS: Despite the homogeneous genomic landscape, the TCR repertoire is extremely heterogeneous in MPM. Dasatinib may potentially induce T-cell response leading to improved survival.

Peripheral cytokines are not influenced by the type of surgical approach for non-small cell lung cancer by four weeks postoperatively.

OBJECTIVES: The influence of surgical approach on systemic inflammatory response and the subsequent oncologic impact for non-small cell lung cancer is debated. We aimed to measure the effects of thoracic surgical approach on peripheral cytokine milieu over time. METHODS: Patients undergoing primary lung resection without neoadjuvant therapy (2016-2018) were evaluated. A panel of 43 cytokines, angiogenic factors, and inflammatory molecules (CAFs) were evaluated in peripheral blood preoperatively, at 24 -hs and 4-weeks postoperatively. Differences between CAFs in patients undergoing thoracotomy versus video-assisted thoracoscopic surgery (VATS) at all timepoints were assessed using Student's t-test. RESULTS: 76 patients with available peripheral CAF panels met inclusion criteria. Thoracotomy was performed in 53 (70 %) patients while VATS was undertaken in 23 (30 %). Upon examination of known inflammatory CAFs, including IL-1ß, IL-6, IL-8, IL-10, IFN-γ, and soluble (s) CD27, no differences were detected at 24 h or 4 weeks postoperatively between surgical groups. Examination of trends over time did not demonstrate any temporal derangements for these CAFs, with return to baseline levels by 4 weeks postoperatively for both groups. Evaluation of soluble (s) checkpoint molecules, including sPD-1, sPD-L1, sTIM-3, and sCTLA-4, did not reveal any differences in the immediate postoperative or long-term recovery period. CONCLUSIONS: Peripheral immune profiles following pulmonary resection do not appear to differ between VATS and thoracotomy postoperatively. CAF fluctuations are transient and recover rapidly. These results, at the peripheral cytokine level, suggest that the surgical approach for lung cancer is unlikely to alter the effectiveness of novel immune-modulating systemic therapies, although more studies are needed to validate these findings.

Programmed Death-Ligand 1 Heterogeneity and Its Impact on Benefit From Immune Checkpoint Inhibitors in NSCLC.

INTRODUCTION: Programmed death-ligand 1 (PD-L1) expression may vary in different disease sites and at different time points of the disease course. We aimed to investigate PD-L1 heterogeneity and its usefulness as a predictive value for immune checkpoint inhibitor (ICI) therapy in patients with NSCLC. METHODS: PD-L1 expression was analyzed in 1398 patients with NSCLC. The predictive value of PD-L1 for ICIs in 398 patients with metastatic NSCLC was assessed. RESULTS: PD-L1 was significantly associated with biopsy sites (p = 0.004). Adrenal, liver, and lymph node (LN) metastases had the highest PD-L1 expression as a continuous variable and at 1% or 50% cutoff. PD-L1 expression was lower in bone and brain metastases. Among 112 patients with two specimens tested, 55 (49%) had major changes in PD-L1 falling into different clinically relevant categories (<1%, 1%-49%, ≥50%) at different time points. Previous ICI therapy was associated with significant decrease in PD-L1 compared with treatment-naive counterparts (p = 0.015). Patients with metastatic NSCLC treated with ICI (n = 398) were divided into three cohorts on the basis of biopsy sites: lung (n = 252), LN (n = 85), and distant metastasis (n = 61). Higher PD-L1 in lung or distant metastasis specimens was associated with higher response rate, longer progression-free survival, and overall survival. However, PD-L1 in LN biopsies was not associated with either response or survival. CONCLUSIONS: PD-L1 varies substantially across different anatomical sites and changes during the clinical course. PD-L1 from different biopsy sites may have different predictive values for benefit from ICIs in NSCLC.

Neutrophil expansion defines an immunoinhibitory peripheral and intratumoral inflammatory milieu in resected non-small cell lung cancer: a descriptive analysis of a prospectively immunoprofiled cohort.

BACKGROUND: The biological underpinnings of the prognostic and predictive significance of a relative neutrophilia in patients with non-small lung cancer (NSCLC) are undefined. We sought to comprehensively examine the relationships between circulating and intratumoral neutrophil populations and features of the immune contexture in patients undergoing NSCLC resection. METHODS: Preoperative soluble cytokine and angiogenic factors; tumor multiplex immunofluorescence; RNA, whole exome, and T-cell receptor sequencing; and flow cytometry were analyzed for relationships with populations of circulating (from complete blood counts) and intratumoral neutrophils (transcriptional signatures) in a prospectively enrolled resected NSCLC cohort (n=66). In a historical cohort (n=1524), preoperative circulating neutrophil and lymphocyte counts were analyzed for associations with overall survival (OS). RESULTS: Circulating neutrophil populations were positively correlated with increased tumor burden, and surgical tumor resection was followed by a subsequent reduction in peripheral neutrophil counts. Expansion of the circulating neutrophil compartment was associated with increased levels of pro-granulopoietic (IL-1ß, IL-17A, TNFα, IL-6) and TH2-associated (IL-5, IL-13) cytokines. Tumors with high intratumoral neutrophil burden were marked by a blunted T-cell response characterized by reduced expression of cytotoxic T-cell genes (CD8A, CD8B, GZMA, GZMB), decreased CD3+CD8+ cell infiltration, and diminished expression of IFNγ-related genes. The associations between increased intratumoral neutrophil burden and reduced CD3+CD8+ infiltration persisted after adjustment for tumor size, histology, mutational burden, and PD-L1 expression. In 1524 patients, elevated preoperative circulating neutrophil count was independently associated with worse OS (main effect HR 1.82, 95% CI 1.24 to 2.68, p=0.002). CONCLUSIONS: Our findings demonstrate that neutrophil expansion reflects protumorigenic and immunosuppressive processes that manifest as worse OS in patients undergoing NSCLC resection. These results justify further investigation of therapeutic strategies targeting neutrophil-associated immune evasion.

Membrane-Binding Cooperativity and Coinsertion by C2AB Tandem Domains of Synaptotagmins 1 and 7.

Synaptotagmin-1 (Syt-1) and synaptotagmin-7 (Syt-7) contain analogous tandem C2 domains, C2A and C2B, which together sense Ca2+ to bind membranes and promote the stabilization of exocytotic fusion pores. Syt-1 triggers fast release of neurotransmitters, whereas Syt-7 functions in processes that involve lower Ca2+ concentrations such as hormone secretion. Syt-1 C2 domains are reported to bind membranes cooperatively, based on the observation that they penetrate farther into membranes as the C2AB tandem than as individual C2 domains. In contrast, we previously suggested that the two C2 domains of Syt-7 bind membranes independently, based in part on measurements of their liposome dissociation kinetics. Here, we investigated C2A-C2B interdomain cooperativity with Syt-1 and Syt-7 using directly comparable measurements. Equilibrium Ca2+ titrations demonstrate that the Syt-7 C2AB tandem binds liposomes lacking phosphatidylinositol-4,5-bisphosphate (PIP2) with greater Ca2+ sensitivity than either of its individual domains and binds to membranes containing PIP2 even in the absence of Ca2+. Stopped-flow kinetic measurements show differences in cooperativity between Syt-1 and Syt-7: Syt-1 C2AB dissociates from PIP2-free liposomes much more slowly than either of its individual C2 domains, indicating cooperativity, whereas the major population of Syt-7 C2AB has a dissociation rate comparable to its C2A domain, suggesting a lack of cooperativity. A minor subpopulation of Syt-7 C2AB dissociates at a slower rate, which could be due to a small cooperative component and/or liposome clustering. Measurements using an environment-sensitive fluorescent probe indicate that the Syt-7 C2B domain inserts deeply into membranes as part of the C2AB tandem, similar to the coinsertion previously reported for Syt-1. Overall, coinsertion of C2A and C2B domains is coupled to cooperative energetic effects in Syt-1 to a much greater extent than in Syt-7. The difference can be understood in terms of the relative contributions of C2A and C2B domains toward membrane binding in the two proteins.

Targeted Tissue and Cell-Free Tumor DNA Sequencing of Advanced Lung Squamous-Cell Carcinoma Reveals Clinically Significant Prevalence of Actionable Alterations.

BACKGROUND: Major guidelines do not recommend routine molecular profiling of lung squamous-cell carcinoma (LUSC) because the prevalence of actionable alterations is thought to be low. Increased utilization of next-generation sequencing (NGS), particularly with cell-free circulating tumor DNA, facilitates reevaluation of this premise. PATIENTS AND METHODS: We retrospectively evaluated the prevalence of actionable alterations in 2 distinct LUSC cohorts totaling 492 patients. A total of 410 consecutive patients with stage 3B or 4 LUSC were tested with a targeted cell-free circulating DNA NGS assay, and 82 patients with LUSC of any stage were tested with a tissue NGS cancer panel. RESULTS: In the overall cohort, 467 patients (94.9%) had a diagnosis of LUSC, and 25 patients (5.1%) had mixed histology with a squamous component. A total of 10.5% of the LUSC subgroup had somatic alterations with therapeutic relevance, including in EGFR (2.8%), ALK/ROS1 (1.3%), BRAF (1.5%), and MET amplification or exon 14 skipping (5.1%). Sixteen percent of patients with mixed histology had an actionable alteration. In the LUSC subgroup, 3 evaluable patients were treated with targeted therapy for an actionable alteration; all of them experienced partial response. CONCLUSION: In this large, real-world LUSC cohort, we observed a clinically significant prevalence of actionable alterations. Accurate local histopathologic assessment in advanced-stage LUSC can be challenging. Further evaluation of the genomic landscape in this setting is warranted to potentially identify underappreciated treatment options.

COPD-Type lung inflammation promotes K-ras mutant lung cancer through epithelial HIF-1α mediated tumor angiogenesis and proliferation.

Chronic obstructive pulmonary disease (COPD), an inflammatory disease of the lung, is an independent risk factor for lung cancer. Lung tissues obtained from human smokers with COPD and lung cancer demonstrate hypoxia and up-regulated hypoxia inducible factor-1 (HIF-1). HIF-1 activation is the central mechanism for controlling the cellular response to hypoxia during inflammation and tumor development. These facts suggest a link between COPD-related airway inflammation, HIF-1, and lung cancer. We have previously established a mouse model of COPD-like airway inflammation that promotes lung cancer in a K-ras mutant mouse model (CC-LR). Here we show that tumors in the CC-LR model have significantly elevated levels of HIF-1α and HIF-1 activity. To determine the tumor-promoting functions of HIF-1 in CC-LR mice, the gene Hif1a which encodes HIF-1α and is required for HIF-1 activity, was disrupted in the lung epithelium of CC-LR animals. Airway epithelial specific HIF-1α deficient mice demonstrated significant reductions in lung surface tumor numbers, tumor angiogenesis, and tumor cell proliferation in the absence or presence of COPD-like airway inflammation. In addition, when CC-LR mice were bred with transgenic animals that overexpress a constitutively active mutant form of human HIF-1α in the airway epithelium, both COPD- and adenocarcinoma-like phenotypes were observed. HIF-1α overexpressing CC-LR mice had significant emphysema, and they also showed potentiated tumorigenesis, angiogenesis, and cell proliferation accompanied by an invasive metastatic phenotype. Our gain and loss of function studies support a key role for HIF-1α in the promotion of lung cancer by COPD-like inflammation.

The HGF/c-MET Pathway Is a Driver and Biomarker of VEGFR-inhibitor Resistance and Vascular Remodeling in Non-Small Cell Lung Cancer.

Purpose: Resistance to VEGFR inhibitors is a major obstacle in the treatment of non-small cell lung cancer (NSCLC). We investigated the cellular mechanisms mediating resistance of NSCLCs to VEGFR tyrosine kinase inhibitors.Experimental Design: We generated murine models of human NSCLC and performed targeted inhibition studies with the VEGFR TKIs cediranib and vandetanib. We used species-specific hybridization of microarrays to compare cancer (human) and stromal (mouse) cell transcriptomes of TKI-sensitive and -resistant tumors. We measured tumor microvascular density and vessel tortuosity to characterize the effects of therapy on the tumor vascular bed. Circulating cytokine and angiogenic factor levels in patients enrolled in VEGFR TKI trials were correlated with clinical outcomes.Results: Murine xenograft models of human lung adenocarcinoma were initially sensitive to VEGFR TKIs, but developed resistance to treatment. Species-specific microarray analysis identified increased expression of stromal-derived hepatocyte growth factor (HGF) as a candidate mediator of TKI resistance and its receptor, c-MET, was activated in cancer cells and tumor-associated stroma. A transient increase in hypoxia-regulated molecules in the initial response phase was followed by adaptive changes resulting in a more tortuous vasculature. Forced HGF expression in cancer cells reduced tumor sensitivity to VEGFR TKIs and produced tumors with tortuous blood vessels. Dual VEGFR/c-MET signaling inhibition delayed the onset of the resistant phenotype and prevented the vascular morphology alterations. In patients with cancer receiving VEGFR TKIs, high pretreatment HGF plasma levels correlated with poorer survival.Conclusions: HGF/c-MET pathway mediates VEGFR inhibitor resistance and vascular remodeling in NSCLC. Clin Cancer Res; 23(18); 5489-501. ©2017 AACR.

Hepatotoxicity with Vismodegib: An MD Anderson Cancer Center and Research on Adverse Drug Events and Reports Project.

BACKGROUND: On 30 January 2012, the US FDA approved vismodegib (Erivedge®, Genentech, CA, USA) for the management of both metastatic and locally advanced basal cell carcinoma. OBJECTIVE: Our objective was to identify evidence of hepatotoxicity with vismodegib in the FDA Adverse Event Reporting System (FAERS) in treated patients in two National Cancer Institute Comprehensive Cancer Centers. METHODS: FAERS was searched for reports dated 1 January 2009 through 31 December 2015 using terms including hedgehog pathway and vismodegib and hepatic-related terms such as liver, jaundice, and hepatitis, among others. Disproportionality analyses with estimates of proportional reporting ratio and empirical Bayesian geometric mean were conducted. A comprehensive literature review was conducted, and the clinical databases at the University of Texas MD Anderson Cancer Center and Robert H. Lurie Comprehensive Cancer Center of Northwestern University were searched. RESULTS: Two cases of severe liver dysfunction were published (Common Terminology Criteria for Adverse Events [CTCAE] class III), and 94 reports of adverse events (AEs) were detected in FAERS, 35 of which were serious AEs. Safety notifications related to hepatotoxicity have not been issued by the manufacturer or the FDA, although vismodegib is listed in LiverTox and the European Medicines Agency website. CONCLUSION: We identified a detectable safety signal for hepatotoxicity for vismodegib within 4 years of FDA approval. Vismodegib should be used in patients with severe liver disease only after careful consideration, and concomitant hepatotoxic medications should be avoided. Rapid dissemination of such safety concerns is expected to result in fewer serious hepatotoxic AEs and more optimal outcomes for patients with cancer receiving vismodegib.

A Randomized Phase II Trial of Short-Course Androgen Deprivation Therapy With or Without Bevacizumab for Patients With Recurrent Prostate Cancer After Definitive Local Therapy.

PURPOSE: Patients with recurrent prostate cancer after local treatment make up a heterogeneous population for whom androgen deprivation therapy (ADT) is the usual treatment. The purpose of this randomized phase II trial was to investigate the efficacy and toxicity of short-course ADT with or without bevacizumab in men with hormone-sensitive prostate cancer. PATIENTS AND METHODS: Eligible patients had an increasing prostate-specific antigen (PSA) of ≤ 50 ng/mL and PSA doubling time of less than 18 months. Patients had either no metastases or low burden, asymptomatic metastases (lymph nodes < 3 cm and five or fewer bone metastases). Patients were randomly assigned 2:1 to a luteinizing hormone-releasing hormone agonist, bicalutamide and bevacizumab or ADT alone, for 6 months. The primary end point was PSA relapse-free survival (RFS). Relapse was defined as a PSA of more than 0.2 ng/mL for prostatectomy patients or PSA of more than 2.0 ng/mL for primary radiation therapy patients. RESULTS: Sixty-six patients received ADT + bevacizumab and 36 received ADT alone. Patients receiving ADT + bevacizumab had a statistically significant improvement in RFS compared with patients treated with ADT alone (13.3 months for ADT + bevacizumab v 10.2 months for ADT alone; hazard ratio, 0.47; 95% CI, 0.29 to 0.77; log-rank P = .002). Hypertension was the most common adverse event in patients receiving ADT + bevacizumab (36%). CONCLUSION: ADT combined with bevacizumab resulted in an improved RFS for patients with hormone-sensitive prostate cancer. Long-term follow-up is needed to determine whether some patients have a durable PSA response and are able to remain off ADT for prolonged periods. Our data provide rationale for combining vascular endothelial growth factor-targeting therapy with ADT in hormone-sensitive prostate cancer.