Telemedicine-based inspiratory muscle training and walking promotion with lung cancer survivors following curative intent therapy: a parallel-group pilot randomized trial.

PURPOSE: Following curative-intent therapy of lung cancer, many survivors experience dyspnea and physical inactivity. We investigated the feasibility, acceptability, safety, and potential efficacy of inspiratory muscle training (IMT) and walking promotion to disrupt a postulated "dyspnea-inactivity" spiral. METHODS: Between January and December 2022, we recruited lung cancer survivors from Kaiser Permanente Colorado who completed curative-intent therapy within 1-6 months into a phase-IIb, parallel-group, pilot randomized trial (1:1 allocation). The 12-week intervention, delivered via telemedicine, consisted of exercise training (IMT + walking), education, and behavior change support. Control participants received educational materials on general exercise. We determined feasibility a priori: enrollment of ≥ 20% eligible patients, ≥ 75% retention, study measure completion, and adherence. We assessed acceptability using the Telemedicine-Satisfaction-and-Usefulness-Questionnaire and safety events that included emergency department visits or hospitalizations. Patient-centered outcome measures (PCOMs) included dyspnea (University-of-California-San-Diego-Shortness-of-Breath-Questionnaire), physical activity (activPAL™ steps/day), functional exercise capacity (mobile-based-six-minute-walk-test), and health-related quality of life (HRQL, St.-George's-Respiratory-Questionnaire). We used linear mixed-effects models to assess potential efficacy. RESULTS: We screened 751 patients, identified 124 eligible, and consented 31 (25%) participants. Among 28 participants randomized (14/group), 22 (11/group) completed the study (79% retention). Intervention participants returned > 90% of self-reported activity logs, completed > 90% of PCOMs, and attended > 90% of tele-visits; 75% of participants performed IMT at the recommended dose. Participants had high satisfaction with tele-visits and found the intervention useful. There was no statistically significant difference in safety events between groups. Compared to control participants from baseline to follow-up, intervention participants had statistically significant and clinically meaningful improved HRQL (SGRQ total, symptom, and impact scores) (standardized effect size: -1.03 to -1.30). CONCLUSIONS: Among lung cancer survivors following curative-intent therapy, telemedicine-based IMT + walking was feasible, acceptable, safe, and had potential to disrupt the "dyspnea-inactivity" spiral. Future efficacy/effectiveness trials are warranted and should incorporate IMT and walking promotion to improve HRQL. TRIAL REGISTRATION: ClinicalTrials.gov NCT05059132.

Phase Ib trial of inhaled iloprost for the prevention of lung cancer with predictive and response biomarker assessment.

Introduction: Iloprost, a prostacyclin analog, has lung cancerpreventive activity in preclinical models and improved dysplasia in former smokers in a phase IIb trial. Oral iloprost is currently unavailable. We performed a phase Ib trial of inhaled iloprost in former smokers to assess tolerance and compliance. Methods: Participants self-administered nebulized iloprost (5ug) or placebo four (QID) or two (BID) times daily. As QID dose was well tolerated and due to expiration of the placebo, the BID dosing and placebo were eliminated early on in the trial. Bronchoscopy with biopsyat six standard sites was performed at treatment initiation and two months post-iloprost, with exploratory histological analysis. Bulk RNA sequencing, single cell RNA sequencing and an in vitro assay of epithelial progenitor cell iloprost response were performed on a subset of biopsies in an exploratory investigation of response mechanisms and predictive biomarkers. Results and discussion: Thirty-four of a planned 48 participants were recruited to the trial.Inhaled iloprost was well tolerated with no adverse events > grade 2. Compliance was 67% in the QID group. The trial was not powered to detect histologic response and none was found. Bulk RNA sequencing of biopsies pre/post iloprost suggest that iloprost is immunomodulatory and downregulates cell proliferation pathways. Single cell RNA sequencing showed an increase in CD8-positive T cells with upregulation of genes in interferon γ signaling. In vitro iloprost response by epithelial progenitor cells correlated with histologic response with kappa coefficient of 0.81 (95% CI 0.47, 1.0). Inhaled iloprost was well tolerated with suboptimal compliance. Molecular analysis suggested that iloprosthas immunomodulatory and antiproliferative effects.The progenitor cell iloprost response assay may be a promising avenue to develop predictive biomarkers. Clinical trial registration: https://clinicaltrials.gov/study/NCT02237183, identifier NCT02237183.

Prevalence, molecular markers, and outcome of bronchial squamous carcinoma in situ in high-risk subjects.

Bronchial squamous carcinoma in situ (CIS) is a preinvasive lesion that is thought to precede invasive carcinoma. We conducted prospective autofluorescence and white light bronchoscopy trials between 1992 and 2016 to assess the prevalence, molecular markers, and outcome of individuals with CIS and other preneoplastic bronchial lesions. Biopsies were evaluated at multiple levels and selected biopsies were tested for aneuploidy and DNA sequenced for TP53 mutation. Thirty-one individuals with CIS were identified. Twenty-two cases of CIS occurred in association with concurrent invasive carcinomas. Seven of the invasive tumors were radiographically occult. In two cases, CIS spread from the focus of invasive carcinoma into contralateral lung lobes, forming secondary invasive tumors. In nine cases, CIS occurred as isolated lesions and one progressed to invasive squamous carcinoma at the same site 40 months after discovery. In a second case, CIS was a precursor of carcinoma at a separate site in a different lobe. In seven cases CIS regressed to a lower grade or disappeared. High level chromosomal aneusomy was often associated with TP53 mutation and with invasive carcinoma. CIS most often occurs in association with invasive squamous carcinoma and may extend along the airways into distant lobes. In rare cases, CIS may be observed to directly transform into invasive carcinoma. CIS may be indicative of invasive tumor at a separate distant site. Isolated CIS may regress. Molecular changes parallel histological changes in CIS and may be used to map clonal expansion in the airways.

Lung cancer survivors' views on telerehabilitation following curative intent therapy: a formative qualitative study.

OBJECTIVES: To inform personalised home-based rehabilitation interventions, we sought to gain in-depth understanding of lung cancer survivors' (1) attitudes and perceived self-efficacy towards telemedicine; (2) knowledge of the benefits of rehabilitation and exercise training; (3) perceived facilitators and preferences for telerehabilitation; and (4) health goals following curative intent therapy. DESIGN: We conducted semi-structured interviews guided by Bandura's Social Cognitive Theory and used directed content analysis to identify salient themes. SETTING: One USA Veterans Affairs Medical Center. PARTICIPANTS: We enrolled 20 stage I-IIIA lung cancer survivors who completed curative intent therapy in the prior 1-6 months. Eighty-five percent of participants had prior experience with telemedicine, but none with telerehabilitation or rehabilitation for lung cancer. RESULTS: Participants viewed telemedicine as convenient, however impersonal and technologically challenging, with most reporting low self-efficacy in their ability to use technology. Most reported little to no knowledge of the potential benefits of specific exercise training regimens, including those directed towards reducing dyspnoea, fatigue or falls. If they were to design their own telerehabilitation programme, participants had a predominant preference for live and one-on-one interaction with a therapist, to enhance therapeutic relationship and ensure correct learning of the training techniques. Most participants had trouble stating their explicit health goals, with many having questions or concerns about their lung cancer status. Some wanted better control of symptoms and functional challenges or engage in healthful behaviours. CONCLUSIONS: Features of telerehabilitation interventions for lung cancer survivors following curative intent therapy may need to include strategies to improve self-efficacy and skills with telemedicine. Education to improve knowledge of the benefits of rehabilitation and exercise training, with alignment to patient-formulated goals, may increase uptake. Exercise training with live and one-on-one therapist interaction may enhance learning, adherence, and completion. Future work should determine how to incorporate these features into telerehabilitation.

Lung adenocarcinoma promotion by air pollutants.

A complete understanding of how exposure to environmental substances promotes cancer formation is lacking. More than 70 years ago, tumorigenesis was proposed to occur in a two-step process: an initiating step that induces mutations in healthy cells, followed by a promoter step that triggers cancer development1. Here we propose that environmental particulate matter measuring ≤2.5 µm (PM2.5), known to be associated with lung cancer risk, promotes lung cancer by acting on cells that harbour pre-existing oncogenic mutations in healthy lung tissue. Focusing on EGFR-driven lung cancer, which is more common in never-smokers or light smokers, we found a significant association between PM2.5 levels and the incidence of lung cancer for 32,957 EGFR-driven lung cancer cases in four within-country cohorts. Functional mouse models revealed that air pollutants cause an influx of macrophages into the lung and release of interleukin-1ß. This process results in a progenitor-like cell state within EGFR mutant lung alveolar type II epithelial cells that fuels tumorigenesis. Ultradeep mutational profiling of histologically normal lung tissue from 295 individuals across 3 clinical cohorts revealed oncogenic EGFR and KRAS driver mutations in 18% and 53% of healthy tissue samples, respectively. These findings collectively support a tumour-promoting role for  PM2.5 air pollutants  and provide impetus for public health policy initiatives to address air pollution to reduce disease burden.

Precision Cut Lung Slices as a Preclinical Model for Non-Small Cell Lung Cancer Chemoprevention.

Lung cancer chemoprevention is critical to addressing cancer burden in high-risk populations. Chemoprevention clinical trials rely on data from preclinical models; however, in vivo studies have high financial, technical, and staffing requirements. Precision cut lung slices (PCLS) provide an ex vivo model that maintains the structure and function of native tissues. This model can be used for mechanistic investigations and drug screenings and reduces the number of animals and time required to test hypotheses compared with in vivo studies. We tested the use of PCLS for chemoprevention studies, demonstrating recapitulation of in vivo models. Treatment of PCLS with the PPARγ agonizing chemoprevention agent iloprost produced similar effects on gene expression and downstream signaling as in vivo models. This occurred in both wild-type tissue and Frizzled 9 knockout tissue, a transmembrane receptor required for iloprost's preventive activity. We explored new areas of iloprost mechanisms by measuring immune and inflammation markers in PCLS tissue and media, and immune cell presence with immunofluorescence. To demonstrate the potential for drug screening, we treated PCLS with additional lung cancer chemoprevention agents and confirmed activity markers in culture. PCLS offers an intermediate step for chemoprevention research between in vitro and in vivo models that can facilitate drug screening prior to in vivo studies and support mechanistic studies with more relevant tissue environments and functions than in vitro models. PREVENTION RELEVANCE: PCLS could be a new model for premalignancy and chemoprevention research, and this work evaluates the model with tissue from prevention-relevant genetic and carcinogen exposed in vivo mouse models, in addition to evaluating chemoprevention agents.

Protocol for intranasal chemoprevention delivery in a urethane mouse lung cancer model.

Mouse iloprost lung cancer chemoprevention studies typically use oral delivery. Here, we present a protocol for intranasal iloprost delivery within a urethane lung adenocarcinoma mouse model. We detail steps for intraperitoneal urethane injection in mice, followed by nine-week monitoring, intranasal iloprost treatment, and lungs harvesting for analysis. This iloprost delivery approach parallels an ongoing phase II clinical trial of inhaled iloprost for lung cancer chemoprevention. This protocol diversifies options for chemoprevention studies and offers a relevant and translatable model. For complete details on the use and execution of this protocol, please refer to Sompel et al. (2022).

Loss of Frizzled 9 in Lung Cells Alters Epithelial Phenotype and Promotes Premalignant Lesion Development.

The transmembrane receptor Frizzled 9 (FZD9) is important for fetal neurologic and bone development through both canonical and non-canonical WNT/FZD signaling. In the adult lung, however, Fzd9 helps to maintain a normal epithelium by signaling through peroxisome proliferator activated receptor γ (PPARγ). The effect of FZD9 loss on normal lung epithelial cells and regulators of its expression in the lung are unknown. We knocked down FZD9 in human bronchial epithelial cell (HBEC) lines and found that downstream EMT targets and PPARγ activity are altered. We used a FZD9-/- mouse in the urethane lung adenocarcinoma model and found FZD9-/- adenomas had more proliferation, increased EMT signaling, decreased activation of PPARγ, increased expression of lung cancer associated genes, increased transformed growth, and increased potential for invasive behavior. We identified PPARγ as a transcriptional regulator of FZD9. We also demonstrated that extended cigarette smoke exposure in HBEC leads to decreased FZD9 expression, decreased activation of PPARγ, and increased transformed growth, and found that higher exposure to cigarette smoke in human lungs leads to decreased FZD9 expression. These results provide evidence for the role of FZD9 in lung epithelial maintenance and in smoking related malignant transformation. We identified the first transcriptional regulator of FZD9 in the lung and found FZD9 negative lesions are more dangerous. Loss of FZD9 creates a permissive environment for development of premalignant lung lesions, making it a potential target for intervention.

PPARgamma agonism inhibits progression of premalignant lesions in a murine lung squamous cell carcinoma model.

The N-nitroso-trischloroethylurea (NTCU)-induced mouse model of squamous lung carcinoma recapitulates human disease from premalignant dysplasia through invasive tumors, making it suitable for preclinical chemoprevention drug testing. Pioglitazone is a peroxisome proliferator-activated receptor γ (PPARγ) agonist shown to prevent lung tumors in preclinical models. We investigated pioglitazone's effect on lesion development and markers of potential preventive mechanisms in the NTCU model. Female FVB/N mice were exposed to vehicle, NTCU or NTCU + oral pioglitazone for 32 weeks. NTCU induces the appearance of basal cells in murine airways while decreasing/changing their epithelial cell makeup, resulting in development of bronchial dysplasia. H&E and keratin 5 (KRT5) staining were used to detect and grade squamous lesions in formalin fixed lungs. mRNA expression of epithelial to mesenchymal transition (EMT) markers and basal cell markers were measured by qPCR. Dysplasia persistence markers desmoglein 3 and polo like kinase 1 were measured by immunohistochemistry. Basal cell markers KRT14 and p63, club cell specific protein and ciliated cell marker acetylated tubulin were measured by immunofluorescence. Pioglitazone treatment significantly reduced squamous lesions and the presence of airway basal cells, along with increasing normal epithelial cells in the airways of NTCU-exposed mice. Pioglitazone also significantly influenced EMT gene expression to promote a more epithelial, and less mesenchymal, phenotype. Pioglitazone reduced the presence of squamous dysplasia and maintained normal airway cell composition. This work increases the knowledge of mechanistic pathways in PPARγ agonism for lung cancer interception and provides a basis for further investigation to advance this chemoprevention strategy.

Iloprost requires the Frizzled-9 receptor to prevent lung cancer.

Prevention of premalignant lesion progression is a promising approach to reducing lung cancer burden in high-risk populations. Substantial preclinical and clinical evidence has demonstrated efficacy of the prostacyclin analogue iloprost for lung cancer chemoprevention. Iloprost activates peroxisome proliferator-activated receptor gamma (PPARG) to initiate chemopreventive signaling and in vitro, which requires the transmembrane receptor Frizzled9 (FZD9). We hypothesized a Fzd 9 -/- mouse would not be protected by iloprost in a lung cancer model. Fzd 9 -/- mice were treated with inhaled iloprost in a urethane model of lung adenoma. We found that Fzd 9 -/- mice treated with iloprost were not protected from adenoma development compared to wild-type mice nor did they demonstrate increased activation of iloprost signaling pathways. Our results established that iloprost requires FZD9 in vivo for lung cancer chemoprevention. This work represents a critical advancement in defining iloprost's chemopreventive mechanisms and identifies a potential response marker for future clinical trials.

Intranasal Iloprost Prevents Tumors in a Murine Lung Carcinogenesis Model.

Lung cancer chemoprevention with the prostacyclin analogue iloprost is the most promising approach to date for intercepting progression of premalignant lung lesions in former smokers. Previous preclinical studies of iloprost used oral delivery, but a study modeling delivery directly to the target organ was needed. In vivo and in vitro studies have identified gene expression changes following iloprost treatment, including increased e-cadherin and Ppargγ and decreased COX2 and vimentin. We used tumor counts and gene expression to demonstrate the effectiveness of intranasal delivery of iloprost in a murine model of premalignant adenomas. Intranasal delivery of iloprost reduced adenoma multiplicity 14 weeks after urethane exposure in FVB/N mice compared with untreated urethane controls. Intranasal iloprost reversed urethane-induced gene expression changes in tumors and whole lung. These results correspond to previous studies of oral iloprost and in vitro treatment of human bronchial epithelial cells. This study demonstrates that intranasal delivery of iloprost in a mouse model of lung premalignant lesions is effective chemoprevention. This will be an essential tool for exploring mechanisms and outcomes of iloprost chemoprevention, along with supporting ongoing clinical trials of inhaled iloprost chemoprevention. PREVENTION RELEVANCE: Iloprost is a promising chemoprevention agent for lung cancer and this work describes a new delivery approach in vivo.

Modifiable factors associated with health-related quality of life among lung cancer survivors following curative intent therapy.

OBJECTIVE: The number of lung cancer survivors is increasing along with advances in screening, diagnosis, and treatment. Following curative intent therapy, many lung cancer survivors experience significant health-related quality of life (HRQL) impairments. We sought to identify potentially modifiable factors that contribute to the HRQL of these patients. MATERIALS AND METHODS: In this cross-sectional observational study of disease-free, stage I-IIIA lung cancer survivors following curative intent therapy, we used a conceptual model to examine factors that included behavioral, objective functional and physiologic, self-rated function and symptom burden, specific comorbidities, and non-modifiable demographic and clinical lung cancer-related characteristics. We assessed HRQL using the valid and prognostic European Organization for Research and Treatment of Cancer Quality of Life (QoL) Core 30 global health/QoL subscale. We used univariable and multivariable linear regression modeling with backward elimination of potentially modifiable and non-modifiable factors, and interpreted clinically and statistically significant, consistent, and independent modifiable factors as meaningful. RESULTS: Among 75 participants at a median of 12 months since treatment completion, the mean (standard deviation) C30 global health/QoL score was 62.7 (23.3) points (0-100 scale range). In multivariable analysis, with and without non-modifiable factors, we identified three clinically and statistically significant, consistent, and independent factors (unstandardized ß range) associated with global health/QoL: 1) abnormal exercise-induced dyspnea (-9.23 to -10.0 points); 2) impaired self-rated role function (or inability to perform work or daily activities and pursuing leisure-time activities) (-12.6 to -16.4 points); and 3) abnormal insomnia (or trouble sleeping) (-12.6 to -16.4 points). CONCLUSION: We identified meaningful modifiable factors associated with the HRQL of disease-free, stage I-IIIA lung cancer survivors following curative intent therapy. Interventions to improve the HRQL of these patients should aim to reduce exercise-induced dyspnea, improve role function - the ability to perform work and other daily including leisure-time activities, and control insomnia.

Association of Leisure-Time Physical Activity With Health-Related Quality of Life Among US Lung Cancer Survivors.

Background: Physical activity and exercise improve function, symptom control, and health-related quality of life (QoL) for many cancer survivors; however, the evidence is limited and inconsistent in lung cancer. We examined the relationship between leisure-time physical activity (LTPA) and health-related QoL in a national sample of US lung cancer survivors. Methods: We conducted a cross-sectional study using the Centers for Disease Control and Prevention Behavioral Risk Factor Surveillance System. We defined LTPA as a self-report of engaging in any physical activity or exercise such as running, calisthenics, golf, gardening, or walking for exercise in the past 30 days, health-related QoL as the number of days of having poor physical or mental health in the past 30 days, and general health status. We analyzed using multivariable logistic regressions with 95% confidence intervals (CIs). Results: Among 614 lung cancer survivors, 316 (51.5%) reported engaging in LTPA. The counts (and proportions) of participants who engaged in LTPA vs no LTPA were, respectively, 135 (42.7%) vs 63 (21.1%) for 0 days of poor physical health, 222 (70.3%) vs 174 (58.4%) for 0 days of poor mental health, and 158 (50.0%) vs 77 (25.8%) for good to excellent general health. In multivariable analyses, participating in LTPA was associated with odds ratios of 2.64 (95% CI = 1.76 to 3.96) and 1.43 (95% CI = 0.97 to 2.10) for 0 days of poor physical and mental health, respectively, and 2.61 (95% CI = 1.74 to 3.91) for good to excellent general health. Conclusions: Participating in LTPA was associated with improved health-related QoL. Interventions to promote LTPA and/or exercise-based rehabilitation may improve QoL among lung cancer survivors.

An Improved Murine Premalignant Squamous Cell Model: Tobacco Smoke Exposure Augments NTCU-Induced Murine Airway Dysplasia.

Tobacco smoke-induced squamous cell lung cancer (SCC) develops from endobronchial dysplastic lesions that progress to invasive disease. A reproducible murine model recapitulating histologic progression observed in current and former smokers will advance testing of new preventive and therapeutic strategies. Previous studies show that prolonged topical application of N-nitroso-tris-chloroethylurea (NTCU) generates a range of airway lesions in sensitive mice similar to those induced by chronic tobacco smoke exposure in humans. To improve the current NTCU model and better align it with human disease, NTCU was applied to mice twice weekly for 4-5 weeks followed by a recovery period before cigarette smoke (CS) or ambient air (control) exposure for an additional 3-6 weeks. Despite the short time course, the addition of CS led to significantly more premalignant lesions (PML; 2.6 vs. 0.5; P < 0.02) and resulted in fewer alveolar macrophages (52,000 macrophages/mL BALF vs. 68,000; P < 0.05) compared with control mice. This improved NTCU + CS model is the first murine SCC model to incorporate tobacco smoke and is more amenable to preclinical studies because of the increased number of PML, decreased number of mice required, and reduced time needed for PML development.

Impact of Proactive Integrated Care on Chronic Obstructive Pulmonary Disease.

BACKGROUND: Up to 50% of chronic obstructive pulmonary disease (COPD) patients do not receive recommended care for COPD. To address this issue, we developed Proactive Integrated Care (Proactive iCare), a health care delivery model that couples integrated care with remote monitoring. METHODS: We conducted a prospective, quasi-randomized clinical trial in 511 patients with advanced COPD or a recent COPD exacerbation, to test whether Proactive iCare impacts patient-centered outcomes and health care utilization. Patients were allocated to Proactive iCare (n=352) or Usual Care ( =159) and were examined for changes in quality of life using the St George's Respiratory Questionnaire (SGRQ), symptoms, guideline-based care, and health care utilization. FINDINGS: Proactive iCare improved total SGRQ by 7-9 units (p < 0.0001), symptom SGRQ by 9 units (p<0.0001), activity SGRQ by 6-7 units (p<0.001) and impact SGRQ by 7-11 units (p<0.0001) at 3, 6 and 9 months compared with Usual Care. Proactive iCare increased the 6-minute walk distance by 40 m (p<0.001), reduced annual COPD-related urgent office visits by 76 visits per 100 participants (p<0.0001), identified unreported exacerbations, and decreased smoking (p=0.01). Proactive iCare also improved symptoms, the body mass index-airway obstruction-dyspnea-exercise tolerance (BODE) index and oxygen titration (p<0.05). Mortality in the Proactive iCare group (1.1%) was not significantly different than mortality in the Usual Care group (3.8%; p=0.08). INTERPRETATION: Linking integrated care with remote monitoring improves the lives of people with advanced COPD, findings that may have been made more relevant by the coronavirus 2019 (COVID-19) pandemic.

A Randomized Phase II Trial of Pioglitazone for Lung Cancer Chemoprevention in High-Risk Current and Former Smokers.

Lung cancer chemoprevention, especially in high-risk former smokers, has great potential to reduce lung cancer incidence and mortality. Thiazolidinediones prevent lung cancer in preclinical studies, and diabetics receiving thiazolidinediones have lower lung cancer rates which led to our double-blind, randomized, phase II placebo-controlled trial of oral pioglitazone in high-risk current or former smokers with sputum cytologic atypia or known endobronchial dysplasia. Bronchoscopy was performed at study entry and after completing 6 months of treatment. Biopsies were histologically scored, and primary endpoint analysis tested worst biopsy scores (Max) between groups; Dysplasia index (DI) and average score (Avg) changes were secondary endpoints. Biopsies also received an inflammation score. The trial accrued 92 subjects (47 pioglitazone, 45 placebo), and 76 completed both bronchoscopies (39 pioglitazone, 37 placebo). Baseline dysplasia was significantly worse for current smokers, and 64% of subjects had mild or greater dysplasia at study entry. Subjects receiving pioglitazone did not exhibit improvement in bronchial dysplasia. Former smokers treated with pioglitazone exhibited a slight improvement in Max, while current smokers exhibited slight worsening. While statistically significant changes in Avg and DI were not observed in the treatment group, former smokers exhibited a slight decrease in both Avg and DI. Negligible Avg and DI changes occurred in current smokers. A trend toward decreased Ki-67 labeling index occurred in former smokers with baseline dysplasia receiving pioglitazone. While pioglitazone did not improve endobronchial histology in this high-risk cohort, specific lesions showed histologic improvement, and further study is needed to better characterize responsive dysplasia.

Prostacyclin and EMT Pathway Markers for Monitoring Response to Lung Cancer Chemoprevention.

Lung cancer is the leading cause of cancer death worldwide and global burden could be reduced through targeted application of chemoprevention. The development of squamous lung carcinoma has been linked with persistent, high-grade bronchial dysplasia. Bronchial histology improved in former smokers in a chemoprevention trial with the prostacyclin analogue iloprost. Prostacyclin acts through peroxisome proliferator-activated receptor gamma (PPARγ) to reverse epithelial to mesenchymal transition and promote anticancer signaling. We hypothesized that the prostacyclin signaling pathway and EMT could provide response markers for prostacyclin chemoprevention of lung cancer. Human bronchial epithelial cells were treated with cigarette smoke condensate (CSC) or iloprost for 2 weeks, CSC for 16 weeks, or CSC for 4 weeks followed by 4 weeks of CSC and/or iloprost, and RNA was extracted. Wild-type or prostacyclin synthase transgenic mice were exposed to 1 week of cigarette smoke or one injection of urethane, and RNA was extracted from the lungs. We measured potential markers of prostacyclin and iloprost efficacy in these models. We identified a panel of markers altered by tobacco carcinogens and inversely affected by prostacyclin, including PPARγ, 15PGDH, CES1, COX-2, ECADHERIN, SNAIL, VIMENTIN, CRB3, MIR34c, and MIR221 These data introduce a panel of potential markers for monitoring interception of bronchial dysplasia progression during chemoprevention with prostacyclin. Chemoprevention is a promising approach to reduce lung cancer mortality in a high-risk population. Identifying markers for targeted use is critical for success in future clinical trials of prostacyclin for lung cancer chemoprevention. Cancer Prev Res; 11(10); 643-54. ©2018 AACR.

Altered Cell-Cycle Control, Inflammation, and Adhesion in High-Risk Persistent Bronchial Dysplasia.

Persistent bronchial dysplasia is associated with increased risk of developing invasive squamous cell carcinoma (SCC) of the lung. In this study, we hypothesized that differences in gene expression profiles between persistent and regressive bronchial dysplasia would identify cellular processes that underlie progression to SCC. RNA expression arrays comparing baseline biopsies from 32 bronchial sites that persisted/progressed to 31 regressive sites showed 395 differentially expressed genes [ANOVA, FDR ≤ 0.05). Thirty-one pathways showed significantly altered activity between the two groups, many of which were associated with cell-cycle control and proliferation, inflammation, or epithelial differentiation/cell-cell adhesion. Cultured persistent bronchial dysplasia cells exhibited increased expression of Polo-like kinase 1 (PLK1), which was associated with multiple cell-cycle pathways. Treatment with PLK1 inhibitor induced apoptosis and G2-M arrest and decreased proliferation compared with untreated cells; these effects were not seen in normal or regressive bronchial dysplasia cultures. Inflammatory pathway activity was decreased in persistent bronchial dysplasia, and the presence of an inflammatory infiltrate was more common in regressive bronchial dysplasia. Regressive bronchial dysplasia was also associated with trends toward overall increases in macrophages and T lymphocytes and altered polarization of these inflammatory cell subsets. Increased desmoglein 3 and plakoglobin expression was associated with higher grade and persistence of bronchial dysplasia. These results identify alterations in the persistent subset of bronchial dysplasia that are associated with high risk for progression to invasive SCC. These alterations may serve as strong markers of risk and as effective targets for lung cancer prevention.Significance: Gene expression profiling of high-risk persistent bronchial dysplasia reveals changes in cell-cycle control, inflammatory activity, and epithelial differentiation/cell-cell adhesion that may underlie progression to invasive SCC. Cancer Res; 78(17); 4971-83. ©2018 AACR.

Targeted overexpression of prostacyclin synthase inhibits lung tumor progression by recruiting CD4+ T lymphocytes in tumors that express MHC class II.

Lung-specific overexpression of prostacyclin synthase (PGIS) decreases tumor initiation in murine lung cancer models. Prostacyclin analogs prevent lung tumor formation in mice and reverse bronchial dysplasia in former smokers. However, the effect of prostacyclin on lung cancer progression has not been well studied. We investigated the effects of pulmonary PGIS overexpression in an orthotopic immunocompetent mouse model of lung cancer using two murine lung cancer cell lines. Pulmonary PGIS overexpression significantly inhibited CMT167 lung tumor growth, increased CXCL9 expression, and increased CD4+ tumor-infiltrating lymphocytes. Immunodepletion of CD4+ T cells abolished the inhibitory effect of pulmonary PGIS overexpression on CMT167 lung tumor growth. In contrast, pulmonary PGIS overexpression failed to inhibit growth of a second murine lung cancer cell line, Lewis Lung Carcinoma (LLC) cells, and failed to increase CXCL9 expression or CD4+ T lymphocytes in LLC lung tumors. Transcriptome profiling of CMT167 cells and LLC cells recovered from tumor-bearing mice demonstrated that in vivo, CMT167 cells but not LLC cells express MHC class II genes and cofactors necessary for MHC class II processing and presentation. These data demonstrate that prostacyclin can inhibit lung cancer progression and suggest that prostacyclin analogs may serve as novel immunomodulatory agents in a subset of lung cancer patients. Moreover, expression of MHC Class II by lung cancer cells may represent a biomarker for response to prostacyclin.