TWIST1 is a critical downstream target of the HGF/MET pathway and is required for MET driven acquired resistance in oncogene driven lung cancer

MET amplification/mutations are important targetable oncogenic drivers in NSCLC, however, acquired resistance is inevitable and the majority of patients with targetable MET alterations fail to respond to MET tyrosine kinase inhibitors (TKIs). Furthermore, MET amplification is among the most common mediators of TKI resistance. As such, novel therapies to target MET pathway and overcome MET TKI resistance are clearly needed. Here we show that the epithelial-mesenchymal transition (EMT) transcription factor, TWIST1 is a key downstream mediator of HGF/MET induced resistance through suppression of p27 and targeting TWIST1 can overcome resistance. We found that TWIST1 is overexpressed at the time of TKI resistance in multiple MET-dependent TKI acquired resistance PDX models. We have shown for the first time that MET directly stabilized the TWIST protein leading to TKI resistance and that TWIST1 was required for MET-driven lung tumorigenesis as well as could induce MET TKI resistance when overexpressed. TWIST1 mediated MET TKI resistance through suppression of p27 expression and genetic or pharmacologic inhibition of TWIST1 overcame TKI resistance in vitro and in vivo. Our findings suggest that targeting TWIST1 may be an effective therapeutic strategy to overcome resistance in MET-driven NSCLC as well as in other oncogene driven subtypes in which MET amplification is the resistance mechanism.

Male sex and pretreatment weight loss are associated with poor outcome in patients with advanced non-small cell lung cancer treated with immunotherapy: a retrospective study

The influence of sex and body mass index (BMI) on the efficacy of immune checkpoint inhibitors (ICIs) in advanced non-small cell lung cancer (NSCLC) patients remains unclear. We conducted a retrospective study to evaluate the relationship between sex, BMI, pretreatment weight loss (PWL), and clinical outcomes in 399 stage IV NSCLC patients treated with ICIs using data abstracted from medical records. Multivariable Cox proportional hazards models were used to assess the impact on overall survival and progression-free survival. Females were significantly more likely to experience immune-related adverse events and had a significantly lower risk of death compared to males in our patient cohort. In stratified analyses, the latter was limited to those receiving first-line monotherapy. BMI was overall not significantly associated with outcome. However, underweight patients had a significantly higher risk of both progression and death compared to normal weight patients in the first-line monotherapy group. When stratified by sex, underweight males had a significantly higher risk of progression and death compared to normal weight males. This was not observed among females. Those with PWL had overall significantly worse outcomes compared to those without. In stratified analyses, PWL was associated with significantly worse OS in both females and males. Stratified by treatment, the worse outcome was limited to those receiving ICI monotherapy. In summary, utilizing real-world data, this study suggests that male sex, being underweight, and PWL negatively impact ICI efficacy in NSCLC patients. Therapeutic approaches to improve ICI outcomes in underweight patients and those with PWL should be investigated.

Abstract A019: Targeting STAT3 for lung cancer prevention

Former smokers have an elevated risk of lung cancer and account for a large proportion of newly diagnosed lung cancer. Former smokers with airway dysplasia have received modest benefit in randomized chemoprevention trials, while active smokers have not. More effective chemoprevention agents for former smokers at risk for lung cancer are needed. We previously reported that a cyclic double-stranded DNA oligonucleotide STAT3 decoy (CS3D) administered intravenously (IV) had strong anti-tumor effects in lung cancer xenograft models and was also effective as a chemoprevention agent using a tobacco carcinogen (NNK)-induced lung cancer mouse model that mimics “ex-smokers”. CS3D prevents the binding of activated STAT3 dimers to the promoter of target genes and induces p-STAT3 degradation. Our goal was to develop a clinically applicable direct delivery method of CS3D to the lungs. Using fluorescently tagged CS3D, we evaluated the feasibility and determined the optimal dosing schedule of CS3D administered intratracheally (IT, a mimic of human inhalation) compared to IV in mice. IT delivery 3 times/week provided a high initial drug level that was cleared from the lungs within a few hours, while IV dosing provided lower initial drug levels but persisted up to 8 hrs, with CS3D accumulation over time in the lungs. While the pharmacodynamic effect was also greater with systemic dosing, IT delivery produced inhibition of the STAT3 pathway. Phosphorylated STAT3, VEGF, IL6 and Ki67 expression in NNK-induced lung preneoplasias was down-modulated by IT CS3D delivery after 4 weeks of treatment compared to the mutant oligonucleotide (CS3M), confirming our previous findings with IV delivery. We also demonstrated that CS3D delivered IT altered the pulmonary environment by promoting a pro-inflammatory, anti-tumor response in myeloid cells of the lung directly, or by acting on tumor and stromal components to establish an immune-reactive tumor-microenvironment. No toxicities were found during IT or IV treatment and no organ abnormalities were detected by either regimen. A long-term chemoprevention study of CS3D delivered IT in the ex-smoker lung cancer murine model is underway. Our findings suggest that blocking STAT3 may be a useful strategy for lung cancer prevention, and may involve both inhibition of oncogenic signaling and enhanced anti-tumor immunity.

Citation Format: Jill M. Siegfried, Adam C. Soloff, Autumn Gaither Davis, Amy A. Powers, Seth H. Eisenberg, Laura P. Stabile. Targeting STAT3 for lung cancer prevention [abstract]. In: Proceedings of the Second Biennial NCI Meeting: Translational Advances in Cancer Prevention Agent Development (TACPAD); 2022 Sep 7-9. Philadelphia (PA): AACR; Can Prev Res 2022;15(12 Suppl_2): Abstract nr A019.

Abstract 1091: TWIST1 inhibition overcomes resistance to tyrosine kinase inhibitors in MET driven non-small cell lung cancer

Background: The mesenchymal-epidermal transition (cMET/MET) tyrosine kinase receptor and its ligand, the hepatocyte growth factor (HGF) are overexpressed in a large percentage of non-small cell lung cancers (NSCLCs) and MET mutation and/or amplification leads to oncogene addiction in small subset of NSCLC. In addition, MET amplification is an established mechanism of resistance to EGFR and other oncogenic targeted TKIs. Several MET-inhibitors have been developed and two MET TKIs have been approved for MET exon 14 skipping mutant NSCLC and have shown activity against MET amplified NSCLC. However, long-term efficacy of MET TKIs is limited as acquired resistance is inevitable. HGF overexpression has been identified as one of the mechanisms of resistance to MET TKIs in MET-altered NSCLC, but the mechanism(s) by which the HGF-MET pathway causes resistance are poorly understood. Here, we investigated the requirement of the EMT-transcription factor, TWIST1 in HGF-mediated resistance to MET TKIs and the role of TWIST1 in de-novo and acquired resistance to MET TKIs.

Methods: TWIST1 expression was measured in wild type and TWIST1 over expressing cell lines in presence and absence of HGF. TWIST1 was inhibited with shRNA and harmine. Apoptosis was assessed via immunoblotting and cleaved caspase 3 staining. We utilized MET altered (mutant/amplified) NSCLC cell lines, patient derived xenografts and a novel transgenic mouse model of Hgf, Twist1 overexpressing lung cancer to evaluate TWIST1 as a driver of MET TKI resistance.

Results: We found that HGF induced TWIST1 expression and MET TKI treatment decreased TWIST1 expression through a post-translational mechanism. Re-expression of TWIST1 led to MET TKI resistance in MET amplified or MET mutant cell lines. Conversely, genetic and pharmacological inhibition of TWIST1 sensitizes to MET inhibition and overcame HGF-mediated MET TKI resistance and MET amplification mediated EGFR TKI resistance in vitro and in vivo. Furthermore, the role of TWIST1 in HGF/MET lung tumorigenesis was evaluated both in human NSCLC xenografts and an Hgf-driven NSCLC mouse model. Genetic inhibition of TWIST1 in MET mutant or amplified cell lines prevented tumor growth in vivo. Furthermore, TWIST cooperated with Hgf in a CCSP-Hgf (CH) mice model that constitutively overexpresses Hgf in the lung and develops NSCLC after treatment with the tobacco carcinogen, 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone (NNK) was utilized. We demonstrated that the Twist1 overexpressing CHT (CCSP-rtTA/CCSP-Hgf/Twist1-tetO-luc) mice developed significantly larger and more aggressive tumors as compared to CH and CCSP-rtTA/Twist1-tetO-luc (CT) mice and that continued TWIST1 expression was required for these tumors.

Conclusions: Our findings suggest that targeting TWIST1 may be an effective therapeutic strategy to overcome HGF-MET-driven resistance in MET-driven NSCLC.

Citation Format: Vinod Kumar, Zachary A. Yochum, Princey Devadassan, Eric Huang, Ethan Miller, Vasavi Ayyala, Laura P. Stabile, Timothy F. Burns, Purva H. Rumde. TWIST1 inhibition overcomes resistance to tyrosine kinase inhibitors in MET driven non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1091.

Estrogen Receptor ß in Cancer: To ß(e) or not to ß(e)?

Estrogen receptors (ERs) are known to play an important role in the proper development of estrogen-sensitive organs, as well as in the development and progression of various types of cancer. ERα, the first ER to be discovered, has been the focus of most cancer research, especially in the context of breast cancer. However, ERβ expression also plays a significant role in cancer pathophysiology, notably its seemingly protective nature and loss of expression with oncogenesis and progression. Although ERβ exhibits antitumor activity in breast, ovarian, and prostate cancer, its expression is associated with disease progression and worse prognosis in lung cancer. The function of ERβ is complicated by the presence of multiple isoforms and single nucleotide polymorphisms, in addition to tissue-specific functions. This mini-review explores current literature on ERβ and its mechanism of action and clinical implications in breast, ovarian, prostate, and lung cancer.

Abstract 2218: MET alterations are enriched in lung adenocarcinoma brain metastases and define a distinct molecular and transcriptomic subtype

Lung cancer has the highest incidence of metastases to the brain, with up to 40% of non-small cell lung cancer (NSCLC) patients developing brain metastases (BM). There is a critical need to develop novel treatments to effectively prevent and treat NSCLC BM. MET is a receptor tyrosine kinase that upon binding hepatocyte growth factor (HGF), mediates proliferation, epithelial-mesenchymal transition (EMT), invasion, angiogenesis and metastasis. Recent studies have suggested that the MET pathway may be a significant determinant of metastatic potential to the brain. We evaluated 125 lung adenocarcinoma (LUAD) BM and 477 primary LUAD for MET amplification (amp) by FISH (MET/CEP > 2) as well as other molecular alterations using targeted next-generation sequencing in a subset of LUAD BM (N=74) and primary LUAD (N=171) samples, including 13 paired primary and brain sets. We identified a significant enrichment of MET amp in LUAD BM (19%) compared to primary LUAD (3%; p<0.00001) or liver metastases (4%, N=80; p=0.002). High MET amp (MET/CEP7 ratio >5) was present in 6.5% of BM compared to 1.3% of primary LUAD cases (p=0.0006). In matched samples, BM-specific MET amp was observed. Non-exon 14 skipping MET activating mutations were also significantly more frequent in LUAD BM (22%) compared to primary LUAD (12%; p=0.05), as well as TP53, KRAS, SMAD4, APC, RB1, RET, ABL1, ALK, and VHL variants (adj. p values <0.02). VHL and IDH1 mutations were significantly increased in MET altered compared to non-MET altered BM. In addition, KRAS Q61X variants were more common in LUAD BM compared to LUAD and specifically more common in MET amp BM. We also examined MET activation in paired tumors using an HGF-MET proximity binding, dual-antibody assay. MET expression was increased in the majority of BM compared to the paired LUAD, and there were brain-specific MET activation was observed. RNASeq analysis identified distinct gene signatures in MET amplified (N=11) versus non-MET amplified (N=24) LUAD BM, including upregulation of the EMT and glycolytic pathways. We validated the importance of the EMT transcription factor, TWIST1 in MET-driven NSCLC tumorigenesis preclinically and confirmed activation of the glycolytic pathway in MET amplified NSCLC. Finally, non-invasive strategies to detect brain-specific MET alterations will be needed to identify BM patients who can benefit from MET inhibitors. Therefore, we examined 277 metastatic NSCLC patients that underwent standard of care circulating tumor DNA testing with the Guardant360 platform, and found that both MET mutation and/or amp were more frequently detected in LUAD patients with BM (p=0.04). Together, we show that over a third of LUAD BM patients have MET alterations compared to primary LUAD and may be responsive to MET inhibitors. Further, our liquid biopsy approach may allow us to identify BM-specific alterations for patient selection in clinical trials.

Citation Format: Timothy F. Burns, Sanja Dacic, Maria A. Velez, Ashwin Somasundaram, Saveri Bhattacharya, Anish Chakka, Zachary A. Yochum, Jingxiao Jin, Ethan Miller, Brenda F. Kurland, Riyue Bao, Danielle P. Normolle, Sameer Agnihotri, Uma R. Chandran, Laura P. Stabile. MET alterations are enriched in lung adenocarcinoma brain metastases and define a distinct molecular and transcriptomic subtype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2218.

The effect of sex and BMI on outcomes in patients with metastatic non-small cell lung cancer treated with immunotherapy

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Background: Recent studies suggest that among non-small cell lung cancer (NSCLC) patients treated with immunotherapy (IT), those who are male and/or have higher body mass index (BMI) benefit most; however, the role of other factors such as pretreatment weight loss is not clear. We conducted a retrospective study to further characterize the relationship between sex, BMI and response to IT in NSCLC. Methods: Patients with stage IV NSCLC treated with IT between 2017 and 2019 at UPMC Hillman Cancer Center were included. Demographic and clinical data were obtained from medical records. Chi-square test was used to compare baseline patient characteristics, best response (CR, PR and SD vs. PD), and presence of immune-related adverse events (iRAEs) between BMI and sex categories. Cox proportional hazards models were used to assess the effect of BMI and sex on progression free survival (PFS) and overall survival (OS). Analyses were conducted overall as well as stratified by treatment regime (1st line monotherapy, non-1st line monotherapy, and concurrent chemotherapy). Results: The study population consisted of 297 patients; 50.2% female (N=149), 87.8% white (N=261), and mean age at IT initiation 68 yrs (range: 36-91 yrs). Median follow-up time: 21 months. At IT initiation, 27 patients were underweight (BMI <18.5), 107 normal weight (BMI 18.5-24.9), 96 overweight (BMI 25-29.9), and 67 obese (BMI ≥30). Among underweight patients, weight loss pretreatment (≥10 lbs) was significantly more common ( P=0.02), and response to IT significantly worse (33% vs 61% good response; P=0.005) compared to those with BMI ≥18.5. No significant difference in response was observed between normal, overweight and obese patients, nor between men and women. The presence of iRAEs did not differ by BMI or sex. Females had better OS than males [HR (95%CI): 0.65 (0.47-0.90)] but PFS was similar. In stratified analyses, better OS among females was limited to the concurrent chemotherapy group [0.52 (0.30-0.92)]. Overall, underweight patients had worse OS than those with BMI ≥18.5 [1.71 (1.01-2.92)]; this was not significant after adjusting for pretreatment weight loss [1.48 (0.87-2.53)]. No difference was observed in OS and PFS between normal, overweight and obese patients. In stratified analyses, underweight individuals had worse OS [4.12 (1.55-10.94)] and PFS [3.87 (1.44-10.38)] than those with BMI ≥18.5 when treated with 1st line monotherapy. Weight loss pretreatment was independently associated with worse OS [2.20 (1.51-3.20)] and PFS [1.47 (1.05-2.05)]. Conclusions: In contrast to prior reports, NSCLC patients receiving IT did not benefit from higher BMI or male sex. Females treated with concurrent chemotherapy had improved OS, and pretreatment weight loss was an indicator of poor prognosis. Further study is required to understand the pathobiology behind these predictors.

Syngeneic tobacco carcinogen-induced mouse lung adenocarcinoma model exhibits PD-L1 expression and high tumor mutational burden

Human lung adenocarcinoma (LUAD) in current or former smokers exhibits a high tumor mutational burden (TMB) and distinct mutational signatures. Syngeneic mouse models of clinically relevant smoking-related LUAD are lacking. We established and characterized a tobacco-associated, transplantable murine LUAD cell line, designated FVBW-17, from a LUAD induced by the tobacco carcinogen 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone in the FVB/N mouse strain. Whole-exome sequencing of FVBW-17 cells identified tobacco-associated KrasG12D and Trp53 mutations and a similar mutation profile to that of classic alkylating agents with a TMB greater than 500. FVBW-17 cells transplanted subcutaneously, via tail vein, and orthotopically generated tumors that were histologically similar to human LUAD in FVB/N mice. FVBW-17 tumors expressed programmed death ligand 1 (PD-L1), were infiltrated with CD8+ T cells, and were responsive to anti-PD-L1 therapy. FVBW-17 cells were also engineered to express green fluorescent protein and luciferase to facilitate detection and quantification of tumor growth. Distant metastases to lung, spleen, liver, and kidney were observed from subcutaneously transplanted tumors. This potentially novel cell line is a robust representation of human smoking-related LUAD biology and provides a much needed preclinical model in which to test promising new agents and combinations, including immune-based therapies.

Interplay between estrogen and Stat3/NF-κB-driven immunomodulation in lung cancer

K-ras mutant lung adenocarcinoma (LUAD) is the most common type of lung cancer, displays abysmal prognosis and is tightly linked to tumor-promoting inflammation, which is increasingly recognized as a target for therapeutic intervention. We have recently shown a gender-specific role for epithelial Stat3 signaling in the pathogenesis of K-ras mutant LUAD. The absence of epithelial Stat3 in male K-ras mutant mice (LR/Stat3Δ/Δ mice) promoted tumorigenesis and induced a nuclear factor-kappaB (NF-κB)-driven pro-tumor immune response while reducing tumorigenesis and enhancing anti-tumor immunity in female counterparts. In the present study, we manipulated estrogen and NF-κB signaling to study the mechanisms underlying this intriguing gender-disparity. In LR/Stat3Δ/Δ females, estrogen deprivation by bilateral oophorectomy resulted in higher tumor burden, an induction of NF-κB-driven immunosuppressive response, and reduced anti-tumor cytotoxicity, whereas estrogen replacement reversed these changes. On the other hand, exogenous estrogen in males successfully inhibited tumorigenesis, attenuated NF-κB-driven immunosuppression and boosted anti-tumor immunity. Mechanistically, genetic targeting of epithelial NF-κB activity resulted in reduced tumorigenesis and enhanced the anti-tumor immune response in LR/Stat3Δ/Δ males, but not females. Our data suggest that estrogen exerts a context-specific anti-tumor effect through inhibiting NF-κB-driven tumor-promoting inflammation and provide insights into developing novel personalized therapeutic strategies for K-ras mutant LUAD.

Randomized, phase II study of ficlatuzumab with or without cetuximab in patients with pan-refractory, recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC)

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Background: Patients with pan-refractory R/M HNSCC, with clinical resistance to cytotoxic therapy, anti-EGFR molecular targeting, and immunotherapy, have poor survival. An established tumor-intrinsic resistance mechanism to cetuximab, an anti-EGFR IgG1 monoclonal antibody (mAb), is activation of the hepatocyte growth factor (HGF)/cMet pathway, which converges with the EGFR network at both the PI3K/Akt and MAPK nodes allowing for reciprocal compensation. Moreover, over-expression of HGF in the tumor microenvironment is immunosuppressive. Convergent data suggest that HGF/cMet pathway inhibition concurrent with EGFR blockade may overcome cetuximab resistance. We previously reported a Phase I study of ficlatuzumab, a humanized anti-HGF IgG1 mAb, with cetuximab in cetuximab-resistant R/M HNSCC. The combination showed promising safety, overall response rate (ORR) and progression-free survival (PFS). Preliminary biomarker analyses showed that high circulating cMet was associated with poor PFS whereas serum Veristrat, a proteomic classifier associated with worse prognosis in the setting of anti-EGFR monotherapy, was not. An increase in total peripheral T cells, particularly the CD8+ subset, was associated with treatment response while progression was associated with expansion of a unique myeloid population. We designed a follow-on randomized phase II trial evaluating ficlatuzumab with or without cetuximab in pan-refractory, R/M HNSCC with signaling and immune correlatives. Methods: This is a multicenter phase II trial with a randomized, non-comparative, two-arm design (ficlatuzumab 20 mg/kg with or without cetuximab 500 mg/m2 every 2 weeks) in patients with pan-refractory R/M HNSCC. Key eligibility criteria include: R/M HNSCC; cetuximab resistance (progression during or within 6 months of cetuximab-radiation or palliative cetuximab); platinum resistance; prior exposure to anti-PD1 mAb; ECOG 0-1; consent to baseline research biopsy. The primary objective is to evaluate the efficacy of each arm as measured by PFS. To test the hypothesis that either regimen improves historical PFS from 2 to 3.33 months requires 66 eligible patients. Key secondary endpoints are ORR and survival. Mechanistic biomarkers include tumor HGF/cMet pathway activation, tumor and peripheral immune profiles, soluble cMet, and serum Veristrat. Thirty-five of 66 subjects have enrolled at 6 centers. A Bayesian continuous monitoring rule for futility has not been triggered for either arm. Clinical trial information: NCT03422536 .

Influence of Estrogen on the NSCLC Microenvironment: A Comprehensive Picture and Clinical Implications

Lung cancer mortality represents the leading cause of cancer related deaths in the United States and worldwide. Almost half of these deaths occur in female patients, making lung cancer the most common cause of cancer mortality in women with a higher annual mortality rate than breast, uterine, and ovarian cancers combined. The distinct epidemiological, histological and biological presentation of non-small cell lung cancer (NSCLC) in women combined with extensive preclinical data have demonstrated that the female sex hormone β-estradiol (E2) plays an important role in NSCLC tumorigenesis, prognosis, and treatment response. Estrogen receptors are widely expressed on stromal and immune cells, and estrogen-linked signaling pathways are known to be involved in regulating the response of both the innate and adaptive immune system. Immune evasion has been recognized as a “hallmark” of cancer and immunotherapy has re-defined standard of care treatment for NSCLC. Despite these advancements, the low response rates observed in patients treated with immune checkpoint inhibitors has led to a search for mediators of immunosuppression and ways to augment the action of these agents. We focus on emerging data describing sex differences that modulate immunotherapy efficacy in NSCLC, immunosuppressive properties of E2 that lead to a pro-tumor microenvironment (TME), and the translational potential of altering the immune microenvironment by targeting the estrogen signaling pathway. E2-induced modulation affects multiple cell types within the TME, including cancer-associated fibroblasts, tumor infiltrating myeloid cells, and tumor infiltrating lymphocytes, all of which interplay with lung tumor cells via E2 and estrogen receptor engagement, ultimately shaping the TME that may, in part, be responsible for the sex-based disparities observed in NSCLC. An improved understanding of the role of the estrogen pathway in NSCLC anti-cancer immunity may lead to novel therapeutic approaches for altering the TME to improve the efficacy of immunotherapy agents.

The Impact of Estrogen in the Tumor Microenvironment

Tumor immune escape is now a hallmark of cancer development, and therapies targeting these pathways have emerged as standard of care. Specifically, immune checkpoint signal blockade offers durable responses and increased overall survival. However, the majority of cancer patients still do not respond to checkpoint blockade immune therapy leading to an unmet need in tumor immunology research. Sex-based differences have been noted in the use of cancer immunotherapy suggesting that sex hormones such as estrogen may play an important role in tumor immune regulation. Estrogen signaling already has a known role in autoimmunity, and the estrogen receptor can be expressed across multiple immune cell populations and effect their regulation. While it has been well established that tumor cells such as ovarian carcinoma, breast carcinoma, and even lung carcinoma can be regulated by estrogen, research into the role of estrogen in the regulation of tumor-associated immune cells is still emerging. In this chapter, we discuss the role of estrogen in the tumor immune microenvironment and the possible immunotherapeutic implications of targeting estrogen in cancer patients.

Development of flow cytometry assays for measuring cell-membrane enzyme activity on individual cells

Background: Cell-membrane expressing enzymes such as ADAM (a disintegrin and metalloproteinase) superfamily members are thought to be key catalysts of vital cellular functions. To directly measure these enzymes and determine their association with particular cells and functions, individual-cell membrane-bound enzyme activity assays are required, but unavailable.

Methods: We developed two such assays, using a fluorescence resonance energy transfer (FRET) peptide substrate (FPS) and flow cytometry. One assay measured live-cell natural processing of FPS and binding of its fluorescent product onto individual-cell membrane-bound enzymes. The other assay measured processing of specifically-bound and glutaraldehyde-crosslinked FPS, and consequent generation of its coupled fluorescent product onto individual-cell membrane-bound enzymes.

Results: Confocal-microscopy imaging indicated that proteolytic processing of FPS selectively occurred on and labeled cell membrane of individual cells. The new assays measured specific increases of cell-associated FPS fluorescent product in substrate-concentration-, temperature- and time-dependent manners. A large proportion of processed FPS fluorescent products remained cell-associated after cell washing, indicating their binding to cell-membrane expressing enzymes. The assays measured higher levels of cell-associated FPS fluorescent product on wild-type than ADAM10-knockout mouse fibroblasts and on human monocytes than lymphocytes, which correlated with ADAM10 presence and expression levels on cell membrane, respectively. Furthermore, the enzyme activity assays could be combined with fluorescent anti-ADAM10 antibody staining to co-label and more directly associate enzyme activity and ADAM10 protein levels on cell membrane of individual cells.

Conclusions: We report on two novel assays for measuring cell-membrane anchored enzyme activity on individual cells, and their potential use to directly study specific biology of cell-surface-expressing proteases.

Induction of Lung Tumors and Mutational Analysis in FVB/N Mice Treated with the Tobacco Carcinogen 4-(Methylnitrosamino)-1-(3-Pyridyl)-1-Butanone

Lung cancer remains the leading cause of cancer-related deaths worldwide. In order to understand lung cancer biology and evaluate novel therapeutic strategies, preclinical mouse models have been developed that mimic early and advanced-stage lung cancer. Among autochthonous models, carcinogen-induced systems are valuable preclinical tools since tobacco smoking remains the number one risk factor for lung tumor development. Among the several thousand chemicals within cigarette smoke, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a potent carcinogen with tumorigenic effects described in both mice and humans. Herein, we describe the methodology for inducing lung tumors in mice using the tobacco carcinogen NNK and subsequent lung fixation for quantitative assessment of tumor development and analysis of oncogenic mutations in tumors.

The estrogen pathway as a modulator of response to immunotherapy

Lung cancer is the leading cause of cancer deaths worldwide, with a 5-year survival rate of about 18%. Thus, there is a great need for novel therapeutic approaches to treat non-small-cell lung cancer (NSCLC). Immune checkpoint inhibitors (ICIs) have improved outcomes for a subset of patients, especially those with high programmed death-ligand 1 expression and/or high tumor mutational burden, but have failed in the majority of patients. Increasing evidence suggests that the estrogen signaling pathway may be a therapeutic target in metastatic NSCLC and that the estrogen pathway may play a role in sex-based responses to ICIs. This report will review the epidemiologic, preclinical and clinical data on the estrogen pathway in NSCLC, its implications in sex-based responses to ICIs and the potential use of antiestrogen therapy in combination with ICIs.

A preliminary analysis of interleukin-1 ligands as potential predictive biomarkers of response to cetuximab

BACKGROUND

The epidermal growth factor receptor (EGFR) monoclonal IgG1 antibody cetuximab is approved for first-line treatment of recurrent and metastatic (R/M) HNSCC as a part of the standard of care EXTREME regimen (platinum/5-fluorouracil/cetuximab). This regimen has relatively high response and disease control rates but is generally not curative and many patients will experience recurrent disease and/or metastasis. Therefore, there is a great need to identify predictive biomarkers for recurrence and disease progression in cetuximab-treated HNSCC patients to facilitate patient management and allow for treatment modification. The goal of this work is to assess the potential of activating interleukin-1 (IL-1) ligands (IL-1 alpha [IL-1α], IL-1 beta [IL-1β]) as predictive biomarkers of survival outcomes in HNSCC patients treated with cetuximab-based chemotherapy.

METHODS

Baseline gene, serum and tumor expression of interleukin-1 (IL-1) ligands were analyzed from The Cancer Genome Atlas (TCGA) database or clinical trials of cetuximab-based therapies and interrogated for associations with clinical outcome data.

RESULTS

High tumor gene expression of IL-1β was associated with a more favorable overall survival in cetuximab-treated HNSCC patients but not in non-cetuximab-treated patients. In HNSCC patients treated with cetuximab-based chemotherapy, higher gene and circulating levels of IL-1α and IL-1β were correlated with a more favorable progression free survival compared to patients with low or undetectable levels of IL-1 ligands.

CONCLUSIONS

These findings suggest that IL-1 ligands may function as predictive biomarkers for tumor response to cetuximab-based chemotherapy in HNSCC patients and warrants further investigation and validation in larger clinical studies.

Targeting the Temporal Dynamics of Hypoxia-Induced Tumor-Secreted Factors Halts Tumor Migration

Targeting microenvironmental factors that foster migratory cell phenotypes is a promising strategy for halting tumor migration. However, lack of mechanistic understanding of the emergence of migratory phenotypes impedes pharmaceutical drug development. Using our three-dimensional microtumor model with tight control over tumor size, we recapitulated the tumor size-induced hypoxic microenvironment and emergence of migratory phenotypes in microtumors from epithelial breast cells and patient-derived primary metastatic breast cancer cells, mesothelioma cells, and lung cancer xenograft cells. The microtumor models from various patient-derived tumor cells and patient-derived xenograft cells revealed upregulation of tumor-secreted factors, including matrix metalloproteinase-9 (MMP9), fibronectin (FN), and soluble E-cadherin, consistent with clinically reported elevated levels of FN and MMP9 in patient breast tumors compared with healthy mammary glands. Secreted factors in the conditioned media of large microtumors induced a migratory phenotype in nonhypoxic, nonmigratory small microtumors. Subsequent mathematical analyses identified a two-stage microtumor progression and migration mechanism whereby hypoxia induces a migratory phenotype in the initialization stage, which then becomes self-sustained through a positive feedback loop established among the tumor-secreted factors. Computational and experimental studies showed that inhibition of tumor-secreted factors effectively halts microtumor migration despite tumor-to-tumor variation in migration kinetics, while inhibition of hypoxia is effective only within a time window and is compromised by tumor-to-tumor variation, supporting our notion that hypoxia initiates migratory phenotypes but does not sustain it. In summary, we show that targeting temporal dynamics of evolving microenvironments, especially tumor-secreted factors during tumor progression, can halt tumor migration. SIGNIFICANCE: This study uses state-of-the-art three-dimensional microtumor models and computational approaches to highlight the temporal dynamics of tumor-secreted microenvironmental factors in inducing tumor migration.

The HGF-MET signaling pathway is enriched in LUAC brain metastases

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Background: Brain metastases occur in over 40% of non-small cell lung cancer (NSCLC) patients leading to a poor prognosis. c-Met (MET) is a receptor tyrosine kinase that upon binding hepatocyte growth factor (HGF), mediates proliferation, epithelial-mesenchymal transition (EMT), invasion, angiogenesis and metastasis. We have previously shown that the EMT transcription factor, TWIST1 is required for proliferation in MET driven NSCLC. Therefore, the HGF/MET/TWIST1 pathway may be a significant determinant of metastatic potential to the brain. Methods: We evaluated 125 lung adenocarcinoma (LUAC) brain metastases for MET amplification by FISH as well as other molecular alterations using targeted next generation sequencing in a subset of brain metastases (N = 74) and primary LUAC (N = 171) samples including 13 paired primary and brain sets. MET activation was examined in paired tumors using a HGF-MET proximity binding, dual-antibody assay (VeraTag; Monogram Biosciences). TWIST1 and EMT markers in the paired sets were measured by immunohistochemistry. Results: Compared to primary LUAC, we found that 17 pathogenic variants including TP53, SMAD4, RB1, RET, APC, ALK, FGFR3, EGFR, STK11 and MET alterations were significantly more common in LUAC brain metastases (adj. p values ≤ 0.02). Specifically, MET amplification was significantly enriched in LUAC brain metastases (23/125, 19%) compared to 2-4% in non-brain metastatic and primary sites. Among paired samples, 2/13 brain metastases had MET amplification that was not found in the primary tumor. MET mutations were also present in 16/74 brain cases (22%) compared to 9% (16/171) observed in the lung. VHL mutations were associated with MET altered cases compared to non- MET altered cases. MET expression was increased in the majority of brain metastases compared to the paired LUAC and there were 3 cases with brain specific MET activation. We found that TWIST1 was induced by HGF and determined response to MET TKIs in vitro. Among paired samples, TWIST1 was increased in brain metastases compared to primary LUAC in a subset of cases. Further analyses of TWIST1 and EMT markers is ongoing. Conclusions: Over a third of brain metastases have MET alterations compared to primary LUAC and may be responsive to MET inhibitors.

Randomized phase II study of fulvestrant and erlotinib compared with erlotinib alone in patients with advanced or metastatic non-small cell lung cancer

OBJECTIVES

This open-label, randomized phase II trial evaluated antitumor efficacy of an antiestrogen, fulvestrant, in combination with human epidermal growth factor receptor (EGFR) inhibitor, erlotinib, in advanced non-small cell lung cancer (NSCLC) patients.

MATERIALS AND METHODS

Patients with advanced or metastatic NSCLC, ECOG 0-2, previous chemotherapy unless patient refusal, and no prior EGFR-directed therapy were randomized 2:1 to erlotinib 150 mg oral daily plus 500 mg intramuscular fulvestrant on day 1, 15, 29 and every 28 days thereafter or erlotinib alone 150 mg oral daily. The primary end point was objective response rate (ORR); secondary endpoints included progression free survival (PFS) and overall survival (OS).

RESULTS

Among 106 randomized patients, 100 received at least one dose of study drug. ORR was 16.4% (11 of 67 patients) for the combination versus 12.1% (4 of 33 patients) for erlotinib (p = 0.77). PFS median 3.5 versus 1.9 months [HR = 0.86, 95% CI (0.52-1.43), p = 0.29] and OS median 9.5 versus 5.8 months [HR = 0.92, 95% CI (0.57-1.48), p = 0.74] numerically favored the combination. In an unplanned subset analysis, among EGFR wild type patients (n = 51), but not EGFR mutant patients (n = 17), median PFS was 3.5 versus 1.7 months [HR = 0.35, 95% CI (0.14-0.86), p = 0.02] and OS was 6.2 versus 5.2 months [HR = 0.72, 95% CI (0.35-1.48), p = 0.37] for combined therapy versus erlotinib, respectively. Notably, EGFR WT patients were more likely to be hormone receptor-positive (either estrogen receptor α- and/or progesterone receptor-positive) compared to EGFR mutant patients (50% versus 9.1%, respectively) (p = 0.03). Treatment was well tolerated with predominant grade 1-2 dermatologic and gastrointestinal adverse effects.

CONCLUSION

Addition of fulvestrant to erlotinib was well tolerated, with increased activity noted among EGFR wild type patients compared to erlotinib alone, albeit in an unplanned subset analysis.

Abstract 5889: TWIST1 is a key mediator of HGF-MET-driven resistance to targeted therapies in EGFR mutant and MET-driven lung cancer

The c-Met (MET) receptor and its ligand, hepatocyte growth factor (HGF), have been shown to mediate epithelial-mesenchymal transition (EMT), proliferation, invasion, motility, and angiogenesis. The HGF/MET pathway is frequently altered in non-small cell lung cancer (NSCLC) and has emerged as a targetable oncogenic driver, as patients with MET amplification and/or mutations have demonstrated marked responses to the MET tyrosine kinase inhibitor (TKI), crizotinib. However, long-term efficacy of MET TKIs is limited as acquired resistance is inevitable and almost half of patients with MET alterations fail to respond to MET TKIs. HGF overexpression has been identified as a mechanism of resistance to both MET and EGFR TKIs in MET altered and EGFR mutant NSCLC. Furthermore, MET amplification has been implicated in EGFR TKI resistance. However, the mechanism(s) by which the HGF-MET pathway causes resistance are poorly understood. We have previously shown that the EMT-transcription factor, TWIST1, is required for MET-driven NSCLC. Here, we investigated the requirement of TWIST1 in HGF-mediated resistance to MET and EGFR TKIs and the role of TWIST1 in de novo and acquired resistance to MET and EGFR TKIs. We found that HGF treatment induced EMT in NSCLC cell lines and increased TWIST1 protein expression through a post-translational mechanism. We demonstrated that targeting TWIST1 pharmacologically with the TWIST1 inhibitor, harmine, overcame HGF-mediated resistance to both MET and EGFR TKIs in MET and EGFR-driven NSCLC. This suggests that TWIST1 is specifically required for HGF-mediated resistance to targeted therapies. We also found that TWIST1 is overexpressed in a subset of MET and EGFR altered cell lines and TWIST1 overexpression was sufficient to cause resistance to MET and EGFR TKIs. In MET-driven and EGFR mutant cell lines that express TWIST1 and are resistant to targeted therapies, we demonstrated that harmine treatment resensitized resistant cells to MET and EGFR TKIs, respectively. To investigate the role of TWIST1 overexpression in Hgf-driven lung cancer, we utilized a CCSP-Hgf (CH) mouse model that constitutively overexpresses Hgf in the lung and develops crizotinib-sensitive tumors following treatment with the tobacco carcinogen, nicotine-derived nitrosamine ketone (NNK). We demonstrated that the Twist1 overexpressing CTH (CCSP-rtTA/Twist1-tetO-luc/CCSP-Hgf) mice developed significantly larger tumors in response to NNK as compared to CH and CCSP-rtTA/Twist1-tetO-luc (CT) mice. In summary, we established that HGF-regulated TWIST1 expression and that TWIST1 expression is required for resistance to MET and EGFR TKIs in the presence and absence of HGF overexpression. These studies suggest that targeting TWIST1 may be an effective therapeutic strategy to overcome HGF-MET-driven resistance in EGFR mutant NSCLC as well as MET TKI resistance in MET-driven NSCLC.

Citation Format: Zachary A. Yochum, Suman Chatterjee, Eric H. Huang, Deena M. Maurer, Myriam A. Attar, Sanja Dacic, Laura P. Stabile, Timothy F. Burns. TWIST1 is a key mediator of HGF-MET-driven resistance to targeted therapies in EGFR mutant and MET-driven lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5889.

ADAM10 Sheddase Activity is a Potential Lung-Cancer Biomarker

Background: Increases in expression of ADAM10 and ADAM17 genes and proteins are inconsistently found in cancer lesions, and are not validated as clinically useful biomarkers. The enzyme-specific proteolytic activities, which are solely mediated by the active mature enzymes, directly reflect enzyme cellular functions and might be superior biomarkers than the enzyme gene or protein expressions, which comprise the inactive proenzymes and active and inactivated mature enzymes. Methods: Using a recent modification of the proteolytic activity matrix analysis (PrAMA) measuring specific enzyme activities in cell and tissue lysates, we examined the specific sheddase activities of ADAM10 (ADAM10sa) and ADAM17 (ADAM17sa) in human non-small cell lung-carcinoma (NSCLC) cell lines, patient primary tumors and blood exosomes, and the noncancerous counterparts. Results: NSCLC cell lines and patient tumors and exosomes consistently showed significant increases of ADAM10sa relative to their normal, inflammatory and/or benign-tumor controls. Additionally, stage IA-IIB NSCLC primary tumors of patients who died of the disease exhibited greater increases of ADAM10sa than those of patients who survived 5 years following diagnosis and surgery. In contrast, NSCLC cell lines and patient tumors and exosomes did not display increases of ADAM17sa. Conclusions: This study is the first to investigate enzyme-specific proteolytic activities as potential cancer biomarkers. It provides a proof-of-concept that ADAM10sa could be a biomarker for NSCLC early detection and outcome prediction. To ascertain that ADAM10sa is a useful cancer biomarker, further robust clinical validation studies are needed.

Interaction between the estrogen receptor and fibroblast growth factor receptor pathways in non-small cell lung cancer

The estrogen receptor (ER) promotes non-small cell lung cancer (NSCLC) proliferation. Since fibroblast growth factors (FGFs) are known regulators of stem cell markers in ER positive breast cancer, we investigated whether a link between the ER, FGFs, and stem cell markers exists in NSCLC. In lung preneoplasias and adenomas of tobacco carcinogen exposed mice, the anti-estrogen fulvestrant and/or the aromatase inhibitor anastrozole blocked FGF2 and FGF9 secretion, and reduced expression of the stem cell markers SOX2 and nanog. Mice administered β-estradiol during carcinogen exposure showed increased FGF2, FGF9, SOX2, and Nanog expression in airway preneoplasias. In normal FGFR1 copy number NSCLC cell lines, multiple FGFR receptors were expressed and secreted several FGFs. β-estradiol caused enhanced FGF2 release, which was blocked by fulvestrant. Upon co-inhibition of ER and FGFRs using fulvestrant and the pan-FGFR inhibitor AZD4547, phosphorylation of FRS2, the FGFR docking protein, was maximally reduced, and enhanced anti-proliferative effects were observed. Combined AZD4547 and fulvestrant enhanced lung tumor xenograft growth inhibition and decreased Ki67 and stem cell marker expression. To verify a link between ERβ, the predominant ER in NSCLC, and FGFR signaling in patient tumors, mRNA analysis was performed comparing high versus low ERβ expressing tumors. The top differentially expressed genes in high ERβ tumors involved FGF signaling and human embryonic stem cell pluripotency. These results suggest interaction between the ER and FGFR pathways in NSCLC promotes a stem-like state. Combined FGFR and ER inhibition may increase the efficacy of FGFR inhibitors for NSCLC patients lacking FGFR genetic alterations.

Preclinical Evidence for Combined Use of Aromatase Inhibitors and NSAIDs as Preventive Agents of Tobacco-Induced Lung Cancer

INTRODUCTION

A hormonal role in NSCLC development is well documented. We previously showed that the aromatase inhibitor (AI) anastrozole decreased development of tobacco carcinogen-induced lung tumors in a murine lung cancer prevention model and that aromatase and estrogen receptor were expressed in pulmonary inflammatory cells.

METHODS

We utilized a tobacco carcinogen-induced lung tumor mouse model by treatment with 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone (NNK), to determine whether an AI combined with nonsteroidal anti-inflammatory drugs results in greater lung tumor prevention effects compared to single-agent treatment.

RESULTS

Combination of anastrozole (0.1 mg/kg/d) with aspirin (25 mg/kg/d) after NNK exposure resulted in significantly fewer and smaller lung tumors than did single-agent treatments and was accompanied by maximum decreases in circulating β-estradiol (E2) and interleukin-6, tumor-infiltrating macrophages, and tumoral Ki67, phospho-mitogen-activated protein kinase, phospho-signal transducer and activator of transcription 3, and interleukin-17A expression. Preneoplasia arising after combination treatment showed the lowest Sox-2 expression, suggesting an inhibitory effect on proliferative capacity in the airways by blocking both E2 and inflammation. Anastrozole combined with ibuprofen instead of aspirin also showed enhanced antitumor effects. Moreover, male mice treated with NNK that received E2 in their drinking water showed greater levels of pulmonary macrophages and inflammatory markers than did the control, confirming an E2 effect on inflammation in the microenvironment.

CONCLUSIONS

Our results suggest a benefit to joint targeting of the estrogen and inflammatory pathways for NSCLC prevention. Combining AIs with nonsteroidal anti-inflammatory drugs reduces circulating E2, proinflammatory cytokines, and macrophage recruitment in the lung microenvironment after tobacco exposure. This strategy could be particularly effective in women who have underlying pulmonary inflammatory diseases.

ATM protein is deficient in over 40% of lung adenocarcinomas

Lung cancer is the leading cause of cancer-related mortality in the USA and worldwide, and of the estimated 1.2 million new cases of lung cancer diagnosed every year, over 30% are lung adenocarcinomas. The backbone of 1^st-line systemic therapy in the metastatic setting, in the absence of an actionable oncogenic driver, is platinum-based chemotherapy. ATM and ATR are DNA damage signaling kinases activated at DNA double-strand breaks (DSBs) and stalled and collapsed replication forks, respectively. ATM protein is lost in a number of cancer cell lines and ATR kinase inhibitors synergize with cisplatin to resolve xenograft models of ATM-deficient lung cancer. We therefore sought to determine the frequency of ATM loss in a tissue microarray (TMA) of lung adenocarcinoma. Here we report the validation of a commercial antibody (ab32420) for the identification of ATM by immunohistochemistry and estimate that 61 of 147 (41%, 95% CI 34%-50%) cases of lung adenocarcinoma are negative for ATM protein expression. As a positive control for ATM staining, nuclear ATM protein was identified in stroma and immune infiltrate in all evaluable cases. ATM loss in lung adenocarcinoma was not associated with overall survival. However, our preclinical findings in ATM-deficient cell lines suggest that ATM could be a predictive biomarker for synergy of an ATR kinase inhibitor with standard-of-care cisplatin. This could improve clinical outcome in 100,000's of patients with ATM-deficient lung adenocarcinoma every year.

Caveolin-1 promotes the tumor suppressor properties of oncogene-induced cellular senescence

Oncogene-induced senescence (OIS) is considered a powerful tumor suppressor mechanism. Caveolin-1 acts as a scaffolding protein to functionally regulate signaling molecules. We demonstrate that a lack of caveolin-1 expression inhibits oncogenic K-Ras (K-Ras^G12V)-induced premature senescence in mouse embryonic fibroblasts and normal human bronchial epithelial cells. Oncogenic K-Ras induces senescence by limiting the detoxification function of MTH1. We found that K-Ras^G12V promotes the interaction of caveolin-1 with MTH1, which results in inhibition of MTH1 activity. Lung cancer cells expressing oncogenic K-Ras have bypassed the senescence barrier. Interestingly, overexpression of caveolin-1 restores cellular senescence in both A549 and H460 lung cancer cells and inhibits their transformed phenotype. In support of these findings, our in vivo data demonstrate that overexpression of oncogenic K-Ras (K-Ras^G12D) induces cellular senescence in the lung of wildtype but not caveolin-1-null mice. A lack of K-Ras^G12D-induced premature senescence in caveolin-1-null mice results in the formation of more abundant lung tumors. Consistent with these data, caveolin-1-null mice overexpressing K-Ras^G12D display accelerated mortality. Finally, our animal data were supported by human sample analysis in which we show that caveolin-1 expression is dramatically down-regulated in lung adenocarcinomas from lung cancer patients, both at the mRNA and protein levels, and that low caveolin-1 expression is associated with poor survival. Together, our data suggest that lung cancer cells escape oncogene-induced premature senescence through down-regulation of caveolin-1 expression to progress from premalignant lesions to cancer.

Modification of proteolytic activity matrix analysis (PrAMA) to measure ADAM10 and ADAM17 sheddase activities in cell and tissue lysates

Increases in expression of ADAM10 and ADAM17 genes and proteins have been evaluated, but not validated as cancer biomarkers. Specific enzyme activities better reflect enzyme cellular functions, and might be better biomarkers than enzyme genes or proteins. However, no high throughput assay is available to test this possibility. Recent studies have developed the high throughput real-time proteolytic activity matrix analysis (PrAMA) that integrates the enzymatic processing of multiple enzyme substrates with mathematical-modeling computation. The original PrAMA measures with significant accuracy the activities of individual metalloproteinases expressed on live cells. To make the biomarker assay usable in clinical practice, we modified PrAMA by testing enzymatic activities in cell and tissue lysates supplemented with broad-spectrum non-MP enzyme inhibitors, and by maximizing the assay specificity using systematic mathematical-modeling analyses. The modified PrAMA accurately measured the absence and decreases of ADAM10 sheddase activity (ADAM10sa) and ADAM17sa in ADAM10^-/- and ADAM17^-/- mouse embryonic fibroblasts (MEFs), and ADAM10- and ADAM17-siRNA transfected human cancer cells, respectively. It also measured the restoration and inhibition of ADAM10sa in ADAM10-cDNA-transfected ADAM10^-/- MEFs and GI254023X-treated human cancer cell and tissue lysates, respectively. Additionally, the modified PrAMA simultaneously quantified with significant accuracy ADAM10sa and ADAM17sa in multiple human tumor specimens, and showed the essential characteristics of a robust high throughput multiplex assay that could be broadly used in biomarker studies. Selectively measuring specific enzyme activities, this new clinically applicable assay is potentially superior to the standard protein- and gene-expression assays that do not distinguish active and inactive enzyme forms.

Abstract 1005: Interaction between the estrogen receptor and fibroblast growth factor receptor pathways in non-small cell lung cancer

The estrogen receptor (ER) promotes cell proliferation in non-small cell lung cancer (NSCLC). Since fibroblast growth factors (FGFs) are known regulators of stem cell markers in ER positive breast cancer, we investigated whether a link between the estrogen pathway, FGFs, and stem cell markers could be demonstrated in NSCLC animal models, human cells lines and tumor tissue. In the lungs of female FVB/N mice exposed to the tobacco carcinogen 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone, NNK, treatment with the anti-estrogen fulvestrant and/or the aromatase inhibitor anastrozole blocked secretion of both FGF2 and FGF9, and reduced expression of the stem cell markers SOX2 and nanog. These effects were observed in the normal airway epilthelium as well as in both lung preneoplasias and lung adenomas. To investigate the effects of β-estradiol (E2), male mice were administered E2 in the drinking water during exposure to NNK for 4 weeks. In this mouse model, the incidence of carcinogen-induced lung preneoplasias increased 1.8-fold (p&lt;0.05) with E2 exposure accompanied by increased expression of FGF2, FGF9, SOX2, and nanog in airway preneoplasias demonstrating a relationship between activation of the FGF pathway in the lungs, expansion of cells with a stem cell phenotype, and promotion of pre-cancerous changes. In FGFR1 normal copy number NSCLC cell lines that express multiple FGFR family members and secrete several FGFs, E2 treatment caused a significant increase (up to 4-fold; p&lt;0.05) in release of FGF2, an effect that was completely blocked by fulvestrant. Treatment with fulvestrant also resulted in a 30% reduction in phosphorylation of fibroblast growth factor receptor substrate 2, the FGFR docking protein. Upon co-inhibition of ER and FGFRs using fulvestrant and the pan-FGFR inhibitor AZD4547, significantly enhanced (p&lt;0.01) anti-proliferative effects were observed in FGFR1 normal copy number NSCLC cells that show low sensitivity to FGFR inhibitors as single agents. In NSCLC xenografts, the combination of AZD4547 (daily 12.5 mg/kg) and fulvestrant (30 mg/kg twice weekly) resulted in a significantly greater inhibition (67-85% decrease; p&lt;0.05) of tumor growth and decreased expression of Ki67 and stem cell markers compared to each single agent treatment. Furthermore, tumor histology appeared more differentiated and up to a 25% decrease in malignant cellularity was observed with combination treatment compared to each single agent treatment. In NSCLC patient tumors, high ERB expression correlated with high FGFR1 expression (p&lt;0.001). Taken together, these results suggest that interaction between the ER and FGFR pathways in NSCLC promotes a stem-like state. Combining an FGFR inhibitor with an ER pathway inhibitor could be exploited to increase the efficacy of FGFR inhibitors for NSCLC patients who lack FGFR genetic alterations. Supported by P50 CA090440 and the V-Foundation.

Citation Format: Laura P. Stabile, Natalie J. Rothenberger, Mariya Farooqui, Sanja Dacic, Jill M. Siegfried. Interaction between the estrogen receptor and fibroblast growth factor receptor pathways in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1005. doi:10.1158/1538-7445.AM2017-1005

Phase I study of the anti-HGF monoclonal antibody (mAb), ficlatuzumab, and cetuximab in cetuximab-resistant, recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC)

6038

Background: Cetuximab, an anti-EGFR mAb, is approved for R/M HNSCC but only a minority benefits. Activation of cMet, the receptor for hepatocyte growth factor (HGF), overcomes EGFR inhibition in preclinical models and high serum HGF is associated with resistance in patients (pts). We conducted a phase I trial evaluating the combination of cetuximab and ficlatuzumab, an IgG1 anti-HGF mAb, in pts with cetuximab-resistant, R/M HNSCC. Methods: In this Narayana k-in-a-row phase I design, cetuximab 500 mg/m2 was administered every 2 weeks. Ficlatuzumab dose tiers were 10 mg/kg (tier 1) or 20 mg/kg IV every 2 weeks (tier 2), with inter-patient escalation or de-escalation based on cumulative dose-limiting toxicities (DLT). The recommended phase II dose (RP2D) was set at tier 2 if no DLTs were observed after 8 enrolled pts; expansion continued to n = 12. Key eligibility criteria: R/M HNSCC; recurrence within 6 months of cetuximab-radiation or progression during/within 6 months of palliative cetuximab; ECOG PS 0-1. Candidate biomarkers included serum Veristrat, a proteomic classifier in lung cancer where “good” predicts benefit from anti-EGFR therapy and “poor” indicates resistance and poor prognosis. Results: From Sept 2015–June 2016, 12 pts were enrolled and treated. Primary site: 1 oral cavity; 3 oropharynx (1 p16+); 2 hypopharynx; 5 larynx; 1 external auditory canal. Platinum-refractory: 11/12. Veristrat: 8 poor; 4 good. Three pts were treated at tier 1 and 9 at tier 2. No DLTs were observed. Grade 3 adverse events included: edema (1), hypoalbuminemia (1), infection (2), thromboembolic event (2). Median PFS and OS at RP2D were 6.0 mos (90% CI = 2.0 mos–not reached) and 8.2 mos (90% CI = 2.7 mos–not reached), respectively. Response rate was 17% (90% CI = 0–28%): 2/12 partial response (PR); 1/3 at 10 mg/kg; 1/9 at 20mg/kg. Clinical benefit rate (PR + stable disease) was 67%. Veristrat was not associated with PFS. Conclusions: The RP2D is cetuximab 500 mg/m2 and ficlatuzumab 20 mg/kg every 2 weeks. This well-tolerated combination demonstrated promising activity in pts with poor prognosis, cetuximab-resistant R/M HNSCC. Phase II testing is justified. Clinical trial information: NCT02277197.

Alterations in the Β-catenin pathway in non-small cell lung cancer to define a distinct molecular subtype with prognostic and therapeutic implications

11584

Background: The treatment of non-small cell lung cancer (NSCLC) has been revolutionized by the development of targeted therapy for distinct molecular subsets. Activation of the β-catenin pathway is essential for colorectal carcinoma tumorigenesis and has been implicated in hepatocellular, thyroid and ovarian cancer. The β-catenin pathway is involved in the cell adhesion complex and Wnt signaling. While mutations in this pathway have been reported in NSCLC and β-catenin overexpression correlates with worse survival, its role in lung tumorigenesis is poorly understood. Methods: We performed targeted next generation sequencing using the Ion Torrent Hotspot Cancer Panel v.2 on tumor tissue from 244 NSCLC patients in which we have defined key demographic and clinical parameters including stage and survival. This cohort contained 91 Stage I cases with mRNA expression data using an Illumina platform. Co-occurrence of genes in the β-catenin pathway and 27 other genes in the panel were assessed by Fisher’s exact test, with Benjamini-Hochberg adjustment for multiple comparisons. Results: Seventeen of 244 tumors had mutations in the β-catenin pathway (APC, CTNNB1, and NOTCH1): 10/170 non-squamous NSCLC (6%, 95% CI 3%-10%), and 7/70 squamous NSCLC (10%, 95% CI 5%-19%). The rate of EGFR and RB1 mutations was higher in tumors with b-catenin pathway mutation (5/17 and 2/17) than in those without (13/227 and 0/227, adjusted p = 0.06 for both). The presence of an APC mutation was also associated with higher mRNA expression of the pro-survival protein, BCL2 (n = 91; 5/41 vs. 0/50, unadjusted p = 0.022, adjusted p = 0.3). Furthermore, APC mutations were more frequently observed in tumors with higher levels of EMT markers (high VIM 8% vs. low VIM 0%, unadjusted p = 0.16) and EMT transcription factors (10% vs. low expression 2%, unadjusted p = 0.16). Finally, we observed a trend toward worse overall survival in non-squamous tumors with mutations in the β-catenin pathway (n = 170, log rank test p = 0.07). Conclusions: These studies suggest that tumors with b-catenin pathway alterations are defined by a more mesenchymal and potentially drug resistant subtype which portends a poor prognosis.

Phase 1/2 study of rilotumumab (AMG 102), a hepatocyte growth factor inhibitor, and erlotinib in patients with advanced non-small cell lung cancer

BACKGROUND

Activation of the mesenchymal-epidermal transition factor (MET) tyrosine kinase and its ligand, hepatocyte growth factor (HGF), is implicated in resistance to epidermal growth factor receptor (EGFR) inhibitors. In this phase 1/2 trial, rilotumumab (an anti-HGF antibody) combined with erlotinib was evaluated in patients with metastatic, previously treated non-small cell lung cancer.

METHODS

In phase 1, a dose de-escalation design was adopted with rilotumumab starting at 15 mg/kg intravenously every 3 weeks and oral erlotinib 150 mg daily. In phase 2, the disease control rate (DCR) (according to Response Evaluation Criteria in Solid Tumors) of the combination was evaluated using a Simon 2-stage design. The biomarkers examined included 10 plasma-circulating molecules associated with the EGFR and MET pathways.

RESULTS

Without indications for de-escalation, the recommended phase 2 dose was dose level 0. Overall, 45 response-evaluable patients were enrolled (13 with squamous carcinoma, 32 with adenocarcinoma; 2 had confirmed EGFR mutations, 33 had confirmed wild-type [WT] EGFR, and 7 had KRAS mutations). The DCR for all patients was 60% (90% confidence interval [CI], 47.1%-71.3%). Median progression-free survival was 2.6 months (90% CI, 1.4-2.7 months), and median overall survival was 6.6 months (90% CI, 5.6-8.9 months). Among patients with WT EGFR, the DCR was 60.6% (90% CI, 46.3%-73.3%), median progression-free survival was 2.6 months (90% CI, 1.4-2.7 months), and median overall survival was 7.0 months (90% CI, 5.6-13.4 months). Elevated baseline levels of neuregulin 1 were associated with longer progression-free survival (hazard ratio, 0.41; 95% CI, 0.19-0.87), whereas elevated amphiregulin levels were associated with more rapid progression (hazard ratio, 2.14; 95% CI, 1.48-3.08).

CONCLUSIONS

Combined rilotumumab and erlotinib had an acceptable safety profile, and the DCR met the prespecified criteria for success. In the EGFR WT group, the DCR exceeded published reports for erlotinib alone. High circulating levels of neuregulin 1 may indicate sensitivity to this combination. Cancer 2017;123:2936-44. © 2017 American Cancer Society.

MAP4K4 is a novel MAPK/ERK pathway regulator required for lung adenocarcinoma maintenance

About 76% of patients with lung adenocarcinoma harbor activating mutations in the receptor tyrosine kinase (RTK)/RAS/RAF pathways, leading to aberrant activation of the mitogen-activated protein kinase (MAPK) pathways particularly the MAPK/ERK pathway. However, many lung adenocarcinomas lacking these genomic mutations also display significant MAPK pathway activation, suggesting that additional MAPK pathway alterations remain undetected. This study has identified serine/threonine kinase mitogen-activated protein 4 kinase 4 (MAP4K4) as a novel positive regulator of MAPK/ERK signaling in lung adenocarcinoma. The results showed that MAP4K4 was drastically elevated in lung adenocarcinoma independently of KRAS or EGFR mutation status. Knockdown of MAP4K4 inhibited proliferation, anchorage-independent growth and migration of lung adenocarcinoma cells, and also inhibited human lung adenocarcinoma xenograft growth and metastasis. Mechanistically, we found that MAP4K4 activated ERK through inhibiting protein phosphatase 2 activity. Our results further showed that downregulation of MAP4K4 prevented ERK reactivation in EGFR inhibitor erlotinib-treated lung adenocarcinoma cells. Together, our findings identify MAP4K4 as a novel MAPK/ERK pathway regulator in lung adenocarcinoma that is required for lung adenocarcinoma maintenance.

Hepatocyte Growth Factor/c-Met Signaling in Head and Neck Cancer and Implications for Treatment

Aberrant signaling of the hepatocyte growth factor (HGF)/c-Met pathway has been identified as a promoter of tumorigenesis in several tumor types including head and neck squamous cell carcinoma (HNSCC). Despite a relatively low c-Met mutation frequency, overexpression of HGF and its receptor c-Met has been observed in more than 80% of HNSCC tumors, with preclinical and clinical studies linking overexpression with cellular proliferation, invasion, migration, and poor prognosis. c-Met is activated by HGF through a paracrine mechanism to promote cellular morphogenesis enabling cells to acquire mesenchymal phenotypes in part through the epithelial-mesenchymal transition, contributing to metastasis. The HGF/c-Met pathway may also act as a resistance mechanism against epidermal growth factor receptor (EGFR) inhibition in advanced HNSCC. Furthermore, with the identification of a biologically distinct subset of HNSCC tumors acquired from human papillomavirus (HPV) infection that generally portends a good prognosis, high expression of HGF or c-Met in HPV-negative tumors has been associated with worse prognosis. Dysregulated HGF/c-Met signaling results in an aggressive HNSCC phenotype which has led to clinical investigations for targeted inhibition of this pathway. In this review, HGF/c-Met signaling, pathway alterations, associations with clinical outcomes, and preclinical and clinical therapeutic strategies for targeting HGF/c-Met signaling in HNSCC are discussed.

Myeloid STAT3 Promotes Lung Tumorigenesis by Transforming Tumor Immunosurveillance into Tumor-Promoting Inflammation

One of the most fundamental and challenging questions in the cancer field is how immunity in patients with cancer is transformed from tumor immunosurveillance to tumor-promoting inflammation. Here, we identify the transcription factor STAT3 as the culprit responsible for this pathogenic event in lung cancer development. We found that antitumor type 1 CD4⁺ T-helper (Th1) cells and CD8⁺ T cells were directly counter balanced in lung cancer development with tumor-promoting myeloid-derived suppressor cells (MDSCs) and suppressive macrophages, and that activation of STAT3 in MDSCs and macrophages promoted tumorigenesis through pulmonary recruitment and increased resistance of suppressive cells to CD8⁺ T cells, enhancement of cytotoxicity toward CD4⁺ and CD8⁺ T cells, induction of regulatory T cell (Treg), inhibition of dendritic cells (DC), and polarization of macrophages toward the M2 phenotype. The deletion of myeloid STAT3 boosted antitumor immunity and suppressed lung tumorigenesis. These findings increase our understanding of immune programming in lung tumorigenesis and provide a mechanistic basis for developing STAT3-based immunotherapy against this and other solid tumors. Cancer Immunol Res; 5(3); 257-68. ©2017 AACR.

Expression of PAM50 Genes in Lung Cancer: Evidence that Interactions between Hormone Receptors and HER2/HER3 Contribute to Poor Outcome

Non–small cell lung cancers (NSCLCs) frequently express estrogen receptor (ER) β, and estrogen signaling is active in many lung tumors. We investigated the ability of genes contained in the prediction analysis of microarray 50 (PAM50) breast cancer risk predictor gene signature to provide prognostic information in NSCLC. Supervised principal component analysis of mRNA expression data was used to evaluate the ability of the PAM50 panel to provide prognostic information in a stage I NSCLC cohort, in an all-stage NSCLC cohort, and in The Cancer Genome Atlas data. Immunohistochemistry was used to determine status of ERβ and other proteins in lung tumor tissue. Associations with prognosis were observed in the stage I cohort. Cross-validation identified seven genes that, when analyzed together, consistently showed survival associations. In pathway analysis, the seven-gene panel described one network containing the ER and progesterone receptor, as well as human epidermal growth factor receptor (HER)2/HER3 and neuregulin-1. NSCLC cases also showed a significant association between ERβ and HER2 protein expression. Cases positive for HER2 expression were more likely to express HER3, and ERβ-positive cases were less likely to be both HER2 and HER3 negative. Prognostic ability of genes in the PAM50 panel was verified in an ERβ-positive cohort representing all NSCLC stages. In The Cancer Genome Atlas data sets, the PAM50 gene set was prognostic in both adenocarcinoma and squamous cell carcinoma, whereas the seven-gene panel was prognostic only in squamous cell carcinoma. Genes in the PAM50 panel, including those linking ER and HER2, identify lung cancer patients at risk for poor outcome, especially among ERβ-positive cases and squamous cell carcinoma.

Abstract LB-079: Effect of diet-induced obesity on tobacco carcinogen-induced lung carcinogenesis in mice

Obesity has been shown to increase breast cancer risk by causing inflammation through altered estrogen signaling. Whether obesity plays a similar role in lung carcinogenesis is currently not known. However, the role of estrogen signaling in the development and progression of lung cancer is well-established and the inflammation-estrogen signaling axis may underlie the link between obesity and lung cancer risk as well. We used a preclinical animal model to determine the role of diet-induced obesity in promoting lung carcinogenesis and inflammation caused by tobacco carcinogen exposure [4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone; NNK] and the ability of estrogen pathway and/or inflammatory inhibitors to reduce this effect. Female FVB/N mice were administered a high fat (HF; 60kcal% fat; N = 67) or low fat (LF; 10kcal% fat; N = 66) diet ad libitum starting 2 weeks before NNK exposure until sacrifice. NNK was administered for 4 weeks, followed by a 4 week holding period for preneoplasia development. Subsequently, placebo, the aromatase inhibitor anastrozole (0.1mg/kg; p.o. daily) and/or aspirin (25mg/kg; p.o. daily) treatment was administered for 13 weeks after which lung tumors and blood biomarkers were evaluated. Poisson regression was used to assess differences in tumor number and mixed-effects models for differences in tumor size. Overall, the LF diet resulted in more tumors per animal (HF mean number of tumors 8.8, range 1-16; LF mean number of tumors 11.5, range 5-20), but signficantly larger tumors were observed in the HF fed mice compared to LF fed mice in all four treatment groups (HF mean tumor size 0.60 mm2, range 0.05-12.24 mm2; LF mean tumor size 0.37 mm2, range 0.06-2.14 mm2) which correlated with increased tumor Ki67 expression. Anastrozole and aspirin as single agents were significantly more effective at decreasing tumor number in HF fed mice compared to LF fed mice; however, the combined treatment was equally effective in both dietary groups. Inflammatory cell count in bronchoalveolar lavage fluid, tumor infiltrating inflammatory cells and tumor aromatase, COX-2 and nuclear factor kappa-B expression were all increased in HF compared to LF fed mice. This increased inflammatory response may be responsible for the observed increase in tumor size in the HF fed mice. In addition, levels of circulating inflammatory cytokines such as IL-6, IL-10 and TNF-α were significantly down-modulated by anastrozole and also by combined treatment in LF fed mice but not in HF fed mice. These results suggest that while dietary fat may not affect lung cancer incidence, a HF diet may contribute to lung tumor progression potentially through dysregulation of the inflammation-estrogen signaling axis. Supported by R21 CA184611.

Citation Format: Brenda Diergaarde, Beatriz Kanterewicz, Mary E. Rothstein, Autumn Gaither-Davis, Shira R. Abberbock, Brenda F. Kurland, Laura P. Stabile. Effect of diet-induced obesity on tobacco carcinogen-induced lung carcinogenesis in mice. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-079.

Abstract CT119: Phase II study of dasatinib in combination with cetuximab in recurrent/metastatic head and neck squamous cell carcinoma

Preclinical data indicate that activation of Src family kinases (SFKs) provides a mechanism for circumventing epidermal growth factor receptor (EGFR) targeting in head and neck squamous cell carcinoma (HNSCC). We performed a Simon two-stage, phase II trial combining dasatinib and cetuximab in patients with recurrent/metastatic HNSCC and analyzed candidate blood and tumor biomarkers for association with response. Significant biomarkers were evaluated in additional cetuximab-treated cohorts to evaluate specificity of association with response. Patients received 150 mg daily dasatinib three days after the loading dose of cetuximab; daily dasatinib and weekly cetuximab were continued until progressive disease (PD). Responses were assessed after 6 weeks and every 12 weeks thereafter until PD. Before and after treatment serum levels of interleukin-6 (IL6), transforming growth factor-alpha (TGF-α), hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) were measured by ELISA. Phospho-SFK levels were evaluated in pretreatment archived tumor specimens. Cell line models of HNSCC were assessed for in vitro cell viability following cetuximab-dasatinib treatment and the effects of IL6 modulation on treatment response. Fourteen patients were enrolled and treated during the first stage. The median treatment duration was 47 days. Thirteen patients were evaluable for response: 6 had stable disease (SD) and 7 had PD. No partial or complete response was observed; enrollment was halted according to the pre-specified futility rule. Low baseline serum IL6 levels (&lt;17.85 pg/ml) were associated with clinical benefit, including prolonged SD (p = 0.028) and improved survival (p = 0.009) while other analyzed blood and tissue biomarkers showed no association with clinical outcomes. Low serum IL6 was also associated with SD in analyses of IL6 levels in a separate phase I trial of dasatinib-cetuximab (p = 0.013, n = 14), but IL6 levels were not associated with clinical benefit in a third trial of recurrent/metastatic HNSCC patients treated with cetuximab plus bevacizumab. Enhanced in vitro cell death was observed with combined cetuximab-dasatinib compared to treatment with either agent alone; addition of IL6-containing media abrogated the enhanced killing of HNSCC cell lines by combined cetuximab-dasatinib. Clinical benefit from the dasatinib-cetuximab combination was more likely among patients with low baseline serum IL6 levels. Increased baseline IL6 may activate EGFR- and SFK-independent STAT3 signaling, bypassing dual blockade and conferring resistance to the combined treatment regimen. Post hoc comparisons among cetuximab-containing trials for recurrent/metastatic HNSCC point to low serum IL6 as a candidate predictive marker specific for combined cetuximab-dasatinib, and preclinical studies support IL6 as a modifier of cetuximab-dasatinib response.

Citation Format: Laura P. Stabile, Ann Marie Egloff, Pei Zhou, William E. Gooding, Jennifer R. Grandis, Julie E. Bauman. Phase II study of dasatinib in combination with cetuximab in recurrent/metastatic head and neck squamous cell carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT119.

Survey for human polyomaviruses in cancer

Over the past 8 years, the discovery of 11 new human polyomaviruses (HPyVs) has revived interest in this DNA tumor virus family. Although HPyV infection is widespread and largely asymptomatic, one of these HPyVs, Merkel cell polyomavirus (MCV), is a bona fide human tumor virus. JC virus (JCV), BK virus, HPyV7, and trichodysplasia-spinulosa virus (TSV) can cause nonneoplastic diseases in the setting of immunosuppression. Few specific reagents are available to study the biology of the newly discovered HPyVs. We developed a pan-HPyV-screening method using a cocktail of 3 antibodies that, when combined, recognize T antigen proteins of all HPyVs. We validated detection characteristics of the antibody cocktail by immunoblotting and immunohistochemistry and screened 1,184 cases, including well-defined diseases and tumor tissue microarrays. This assay robustly detected MCV, TSV, JCV, and HPyV7 in etiologically related diseases. We further identified WU polyomavirus in a case of chronic lymphocytic lymphoma-associated bronchitis. Except for scattered, incidentally infected cells in 5% of lung squamous cell carcinomas and colon adenocarcinomas, a broad panel of tumor tissues was largely negative for infection by any HPyV. This method eliminates known HPyVs as suspected causes of cancers investigated in this study. Pan-HPyV survey can be applied to identify diseases associated with recently discovered polyomaviruses.

Abstract 2181: Differential expression of genes related to autoimmunity and metabolism in Stage I NSCLC from patients with COPD

Chronic obstructive pulmonary disease increases lung cancer risk 3-fold, but individuals with COPD may not qualify for lung cancer screening if their age or smoking histories do not meet eligibility criteria. Genomics might reveal genes differentially active in lung tumors from COPD patients, identifying pathways associated with lung cancer in the COPD setting. We used mRNA profiling to identify differences in Stage I non-small cell lung cancers (NSCLC) from patients with and without COPD. COPD was determined by pre-surgery Pulmonary Function Tests (PFTs); the GOLD score was calculated from FEV1 and FVC measurements. Stage I cases were chosen to minimize effect of tumor burden on PFTs. After extraction of mRNA from frozen tumor specimens (71 adenocarcinoma and 24 squamous cell carcinoma), the Illumina HT-12 v4 BeadChip was used to measure mRNA expression. All cases passed RNA quality checks, had not received neo-adjuvant therapy, and had pre-surgical PFT results. 44% of cases were GOLD II-IV (COPD positive) and 56% were GOLD 0-I (COPD negative). In an unbiased examination using the limma R package, 5,789 probes showed expression above background and variation in expression. These probes were compared in COPD positive and negative tumors; no probes were significantly different after multiple comparisons adjustment. In an examination of KEGG pathways by gene set enrichment analysis (GSEA) using a t-test or a linear model that adjusted for age, race, sex and smoking status, 31 pathways (17 in squamous cell and 14 in adenocarcinoma) were identified that were differentially expressed between COPD positive and negative tumors (p value &lt; 0.025 in a 2-tailed test). There was no overlap in significant KEGG Pathways between the two histologies. In squamous cell carcinoma, DNA Replication and Mismatch Repair were repressed in COPD positive tumors, while many Autoimmunity and Infection pathways were activated. In adenocarcinoma, COPD positive tumors showed repression of metabolic pathways including P450, fatty acid, and pentose metabolism. Ingenuity pathway analysis predicted upstream regulators that are reported to control differentially expressed genes contained in the significant KEGG pathways. In squamous cell lung carcinoma, IL27 (p = 2.96 E-36, activation score 3.00), interferon gamma (p = 1.65 E-58, activation score 5.57), and tumor necrosis factor (p = 2.01 E-44, activation score 3.92) were the three top upstream regulators. In adenocarcinoma, PPAR alpha/RXRA (p = 4.83 E -15, inhibition score -2.84), TP53 (p = 3.63 E-08, inhibition score -2.06), and HNF1A (p = 3.88 -08, inhibition score -2.59) were the top three upstream regulators. Results show that distinct pathways are affected by COPD in lung squamous cell and adenocarcinoma, and identify potential biomarkers such as IL27 that may drive squamous cell carcinoma development, while loss of PPAR activity may drive adenocarcinoma, in smokers with COPD. Supported by P50 CA090440.

Citation Format: Jill M. Siegfried, Kan Shang, Cavan Reilly, Laura P. Stabile. Differential expression of genes related to autoimmunity and metabolism in Stage I NSCLC from patients with COPD. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2181. doi:10.1158/1538-7445.AM2015-2181

Abstract 1861: Estrogen modulation of fibroblast growth factor signaling in non-small cell lung cancer

The estrogen signaling pathway induces proliferation in non-small cell lung cancer (NSCLC) and represents a novel therapeutic target for lung cancer. Estrogen receptor β (ERβ) is the predominant ER isoform in lung cancer and we have previously shown that high cytoplasmic ERβ combined with low progesterone receptor (PR) expression is a poor prognostic marker for NSCLC patients. To further elucidate the biological differences between ERβ high/PR low versus ERβ low/PR high expressing lung tumors, a mRNA microarray analysis using the Illumina HT-12 V4 Bead Chip platform was performed using RNA extracted from 64 cases. 165 genes were differentially expressed between these two groups at P&lt;001. Fibroblast growth factor receptor 1 (FGFR1) was a highly over-expressed gene associated with ERβ high tumors (2.1-fold, P&lt;0.004), while the decoy receptor for FGFR ligands, fibroblast growth factor receptor like-1 (FGFR5), was down-regulated (0.54-fold, P&lt;0.0001). Ingenuity Pathway analysis revealed a network among the 165 differentially expressed genes that linked FGFR1 and FGFR5 to the ER. To analyze cross-talk between the FGF and E2 pathways, we determined the FGF/FGFR profile in a panel of three FGFR1 amplified and five non-amplified NSCLC cell lines. FGF2, 3, 10, and 19 were the most highly secreted FGFs in the cell line panel. FGFR1 amplified cells secreted statistically more FGF3, 6 and 10 compared to non-amplified cells. β-estradiol (E2) induced secretion of FGF2 in a cell line without FGFR1 amplification. FGFR3 and 5 were ubiquitously expressed across all cell lines while FGFR1, 2 and 4 expression was higher in amplified cell lines. There was no relationship between ERβ protein expression and FGFR1 amplification status or FGFR1-5 protein expression. Because FGF signaling has been shown to increase stem cell-like phenotypes in breast cancer, we determined basal and E2-stimulated expression of the stem cell markers, SOX2 and OCT4. Basal SOX2 and OCT4 were more highly expressed in FGFR1 amplified cells compared to non-amplified cells. SOX2 and OCT4 protein expression were increased by E2 treatment in FGFR1 non-amplified cells, with lesser effects in FGFR1 amplified H520 cells. SOX2 expression was also down-regulated in lung sections from mice treated with a combination of the anti-estrogen fulvestrant and the aromatase inhibitor anastrozole. Finally, we have shown that in FGFR1 non-amplified cells, the anti-proliferative effect of a pan-FGFR inhibitor, AZD4547, can be enhanced in the presence of the anti-estrogen fulvestrant. These results suggest that there is an interaction between the estrogen and FGF signaling pathways in lung cancer and provides a rationale for combination treatment of NSCLC tumors. Further characterization of the molecular types of NSCLC that will benefit from joint therapy is warranted. This work was supported by P50 CA090440.

Citation Format: Laura P. Stabile, Natalie J. Rothenberger, Marjorie Romkes, Lisa Koodie, Mariya Farooqui, Sanja Dacic, Jill M. Siegfried. Estrogen modulation of fibroblast growth factor signaling in non-small cell lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1861. doi:10.1158/1538-7445.AM2015-1861

Abstract 608: Targeting the estrogen pathway in a male mouse model of lung tumor prevention

A hormonal role in the pathology of lung cancer is well documented. We have shown that the aromatase inhibitor anastrozole and the anti-estrogen fulvestrant effectively inhibited tobacco carcinogen-induced lung tumorigenesis in a female mouse model of lung cancer prevention. Additionally, we have shown that inflammatory cells that infiltrate the lungs in response to carcinogens may be a source of estrogen synthesis, and have confirmed aromatase and estrogen receptor expression in a pure macrophage population of differentiated THP-1 cells. These results suggest that targeting the estrogen pathway may be beneficial for both treatment and prevention of lung cancer. There is no sex difference in expression of estrogen-related markers or in relation of these markers to survival in lung cancer patients, suggesting that both men and women may benefit from hormonal therapy. We hypothesized that aromatase activity is a factor in lung cancer development regardless of sex. Since testosterone can serve as an estrogen precursor, we determined whether blocking estrogen action is a feasible lung tumor prevention strategy in male mice. To standardize the amount of estrogen in each animal, orchiectomized male mice were utilized and exogenous testosterone was administered via slow release pellets or daily androstendione injections. Under these conditions, testosterone or androstendione is converted to estrogen through aromatase. The tobacco carcinogen NNK (24mg) was administered in weeks 1-4 followed by a holding period for preneoplasia development. Placebo or anastrozole (0.1mg/kg; p.o. daily) treatment was administered in weeks 9-21. Treatment group (10-11 mice per group) differences were assessed by Poisson regression for number of tumors, and by linear mixed models for tumor size. Anastrozole inhibited the mean number of NNK induced lung tumors per animal by 23% in orchiectomized male mice without hormonal supplementation (placebo treatment mean= 11; range= 8-13 vs anastrozole mean= 8; range= 6-10; p=0.11), by 62.5% in mice supplemented with testosterone (placebo treatment mean= 8; range= 6-11 vs anastrozole mean= 3; range= 2-4; p&lt;0.001) and by 55% in mice supplemented with androstendione (placebo treatment mean= 12, range= 9-16 vs anastrozole mean= 5; range= 4-7; p&lt;0.001). In intact male mice with no hormonal manipulation, anastrozole inhibited lung tumor formation by 33% (p=0.001). Fulvestrant also showed a significant decrease in lung tumors regardless of hormonal status. Tumor number was decreased in general by testosterone suggesting that testosterone may have an inhibitory effect on lung tumor formation. Tumor size was also decreased by anastrozole and fulvestrant under all experimental conditions. Tumor Ki67 and serum β-estradiol levels at sacrifice were significantly decreased by anastrozole. These results suggest that hormonal therapies may benefit male lung cancer patients. Supported by P50CA090440 and the Lung Cancer Research Foundation.

Citation Format: Laura P. Stabile, Mary E. Rothstein, Brenda F. Kurland, Diana Cunningham, Matthew Orlowski, Jill M. Siegfried. Targeting the estrogen pathway in a male mouse model of lung tumor prevention. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 608. doi:10.1158/1538-7445.AM2014-608

Pan-erbB inhibition potentiates BRAF inhibitors for melanoma treatment

The BRAF inhibitor vemurafenib is currently used for treating patients with BRAF V600E mutant melanoma. However, the responses to vemurafenib are generally partial and of relatively short duration. Recent evidence suggests that activation of the epidermal growth factor receptor (EGFR)/erbB signaling pathway may be responsible for the development of BRAF inhibitor resistance in melanoma patients. In this study, we characterized the erbB family of receptors and ligands in melanoma cell lines and examined whether targeting both BRAF and erbB provided enhanced antitumor activity in BRAF mutant melanoma. Variable levels of erbB2, erbB3, and truncated erbB4 were expressed in both BRAF wildtype and mutant melanoma cells with no significant differences between wildtype and mutant lines. EGFR was rarely expressed. Neuregulin 3 and neuregulin 4 were the major erbB ligands released by melanoma cells. Multi-erbB targeting with the irreversible tyrosine kinase inhibitor canertinib exerted a more effective growth inhibitory effect in both BRAF wildtype and mutant melanoma cells compared with the single-erbB or dual-erbB targeting inhibitors, gefitinib, erlotinib, and lapatinib. Canertinib inhibited both EGF-induced and neuregulin 1-induced erbB downstream signaling in both mutant and wildtype cell lines. However, canertinib induced apoptosis and sub-G1 arrest only in mutant cells. Canertinib statistically increased the antiproliferative effects of vemurafenib in the BRAF mutant melanoma cell lines while little or no enhanced effect was observed with the combination treatment in the wildtype cell lines. A combined inhibition strategy targeting BRAF together with multiple erbB family kinases is potentially beneficial for treating BRAF V600E mutant melanoma. Wildtype BRAF melanoma may also benefit from a multi-erbB kinase inhibitor.

Targeting the estrogen pathway for the treatment and prevention of lung cancer

The estrogen signaling pathway is involved in the biology of non-small-cell lung cancer and represents a novel therapeutic target for lung cancer. This is supported by epidemiological evidence, preclinical studies and recent data from clinical trials. Antiestrogens and inhibitors of estrogen synthesis have been shown to inhibit lung tumor growth as well as prevent lung tumorigenesis in preclinical models both in vitro and in vivo. Two clinical trials testing the effectiveness of hormonal strategies in advanced non-small-cell lung cancer have recently been completed with promising results. Future work in this field should focus on identification of patients that would benefit from hormone modulators so that they can be used earlier in the course of disease or for chemoprevention.

Estrongenic steroid hormones in lung cancer

It is becoming increasingly clear that steroid hormones are involved in the biology of many organs outside the reproductive system. Evidence has been accumulating since the mid 1990s that the lung contains receptors for both estrogen and progesterone and that these hormones have some role in lung development, pulmonary inflammation, and lung cancer. The estrogen receptor β (ERβ) is the major ER expressed in lung tissues, while inflammatory cells capable of infiltrating the lung are reported to express both ERα and ERβ. Although there is evidence in animals of preferential effects of ERβ in the lungs of females, human lung tumors from males also contain ERβ-positive cells and express aromatase, the enzyme that converts testosterone to estrogens. This review will discuss current literature findings on the role of the ERs and the progesterone receptor (PR), as well CYP19 (aromatase), the rate-limiting enzyme in the synthesis of estrogen, in lung cancer.

Genetic variation in ESR2 and estrogen receptor-beta expression in lung tumors

OBJECTIVE

To investigate the association between inherited variation in the estrogen receptor beta (ERβ) gene (ESR2) and ERβ lung tumor expression, a phenotype that possibly affects survival differently in men and women.

METHODS

We genotyped 135 lung cancer patients for 22 ESR2 single nucleotide polymorphisms (SNPs) and measured nuclear and cytoplasmic ERβ expression by immunohistochemistry (IHC) in their primary lung tumor. Distributing Allred ERβ IHC scores according to ESR2 genotype classified under a dominant genetic model, we used rank sum tests to identify ESR2 SNPs significantly associated (p<0.05) with ERβ expression.

RESULTS

35%, 35%, and 29% of lung tumors showed no/low (Allred<6), intermediate (Allred 6-7), and maximal (Allred 8) cytoplasmic ERβ expression, whereas 13%, 27%, and 60% showed no/low, intermediate, and maximal nuclear ERβ expression. For SNPs rs8021944, rs1256061 and rs10146204, ERβ expression was higher according to the rank sum test in lung tumors from patients with at least one minor allele. For each of these three SNPs, the odds of maximal (Allred 8) relative to no/low (Allred<6) ERβ expression was 3-fold higher in tumors from patients with at least one minor allele than in tumors from patients homozygous for the common allele.

CONCLUSION

Inherited variability in ESR2 may determine ERβ lung tumor expression.

Abstract 4664: Result of TORI L-03, a randomized, multicenter phase II clinical trial of erlotinib (E) or E + fulvestrant (F) in previously treated advanced non-small cell lung cancer (NSCLC)

Background: EGFR inhibition is an established therapy for previously treated NSCLC. Estrogen receptors (ER) and aromatase are expressed in most NSCLC specimens in both men and women. In preclinical models, estrogen stimulates NSCLC growth, an effect blocked by F, a pure ER antagonist. Preclinical models show enhanced anti-tumor effects by combining EGFR inhibitors with F.

Methods: We conducted a Phase II clinical study to evaluate whether addition of F enhances antitumor efficacy of E. Men and women with advanced NSCLC and &gt; 1 prior chemotherapy regimen (unless patient refused) were randomized 2:1 to receive E (150 mg PO qd) + F (500 mg IM q2wk x 3, then q4wk) or E alone. Stratification for gender and ECOG (0, 1 vs. 2) was performed. Response rate (RR) was the primary endpoint. Secondary endpoints included progression free survival (PFS), overall survival (OS) and correlation between clinical endpoints and tumor tissue and blood-based biomarkers.

Results: 106 patients (pts) were randomized from March 2006 to June 2010. 100 (evaluated population) received E +/- F. E + F was well tolerated, with adverse events well balanced between arms. For E + F and E respectively, RR (23.6% vs. 14.8%, p = 0.35), PFS [1.9 vs. 1.8 months, hazard ratio (HR) 0.85, 95% confidence interval 0.55, 1.33] and OS [9.4 vs. 5.7 months, HR 0.96 (0.6, 1.55)] were similar between arms. EGFR mutational data could be obtained on 69 pts. EGFR mutations were more prevalent in the E arm (35% vs. 20%). EGFR mutations strongly predicted best response, PFS and OS (p &lt; 0.0002 for each). RR, PFS and OS were similar among EGFR mutants between arms in this small subset (17 patients). Among the 52 pts with EGFR WT tumors, 3 partial responses (PR) were seen with E + F vs. none for E alone. Clinical benefit rate [CBR (RR + stable disease): 54.8% vs. 8.3%, p = 0.0056] was significantly higher among pts with WT tumors treated with E + F. Trends were observed in favor of E + F in PFS [2.0 vs. 1.6 months, HR 0.56 (0.29, 1.07)] and OS [7.4 vs. 5.9 months, HR 0.69 (0.36, 1.31)].

Conclusion: E + F was well tolerated in previously treated NSCLC pts, including men and pre- and post-menopausal women. The study showed a high RR (23.6%) for E + F, that was not adequately explained by EGFR mutations. Among EGFR WT pts, a significantly higher CBR that included 3 PRs was seen with trends towards improved PFS and OS with E + F as compared to E alone. Evaluation of tumor tissue biomarkers (including ER-α and -β, aromatase), blood estrogen levels and EGFR ligands known to be induced by ER signaling is ongoing to determine NSCLC subpopulations most likely to benefit from antiestrogens. [Supported by 1K23CA149079, P50 CA090440, V Foundation for Cancer Research, Jonsson Comprehensive Cancer Center, Wolfen Family Lung Cancer Research Program, Stiles Program in Oncology, National Lung Cancer Partnership and One Ball Matt Memorial Golf Tournament]

Citation Format: Edward B. Garon, Jill M. Siegfried, Steven M. Dubinett, Robert M. Elashoff, David J. Park, Rupesh J. Parikh, Ravi Patel, Eddie H. Hu, Karen L. Reckamp, Brad Adams, Diego Martinez, He-Jing Wang, Fairooz Kabbinavar, Sanja Dacic, Meghan Brennan, Isett Laux, Diana C. Marquez-Garban, Laura P. Stabile, Dennis J. Slamon, Richard J. Pietras. Result of TORI L-03, a randomized, multicenter phase II clinical trial of erlotinib (E) or E + fulvestrant (F) in previously treated advanced non-small cell lung cancer (NSCLC). [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4664. doi:10.1158/1538-7445.AM2013-4664