Deployment-related Cigarette Smoking Behaviors and Pulmonary Function Among U.S. Veterans.

INTRODUCTION: The effects of smoking on lung function among post-9/11 Veterans deployed to environments with high levels of ambient particulate matter are incompletely understood. MATERIALS AND METHODS: We analyzed interim data (04/2018-03/2020) from the Veterans Affairs (VA) Cooperative Studies Program #595, "Service and Health Among Deployed Veterans". Veterans with ≥1 land-based deployments enrolled at 1 of 6 regional Veterans Affairs sites completed questionnaires and spirometry. Multivariable linear regression models assessed associations between cigarette smoking (cumulative, deployment-related and non-deployment-related) with pulmonary function. RESULTS: Among 1,836 participants (mean age 40.7 ± 9.6, 88.6% male), 44.8% (n = 822) were ever-smokers (mean age 39.5 ± 9.5; 91.2% male). Among ever-smokers, 86% (n = 710) initiated smoking before deployment, while 11% (n = 90) initiated smoking during deployment(s). Smoking intensity was 50% greater during deployment than other periods (0.75 versus 0.50 packs-per-day; P < .05), and those with multiple deployments (40.4%) were more likely to smoke during deployment relative to those with single deployments (82% versus 74%). Total cumulative pack-years (median [IQR] = 3.8 [1, 10]) was inversely associated with post-bronchodilator FEV1%-predicted (-0.82; [95% CI] = [-1.25, -0.50] %-predicted per 4 pack-years) and FEV1/FVC%-predicted (-0.54; [95% CI] = [-0.78, -0.43] %-predicted per 4 pack-years). Deployment-related pack-years demonstrated similar point estimates of associations with FEV1%-predicted (-0.61; [95% CI] = [-2.28, 1.09]) and FEV1/FVC%-predicted (-1.09; [95% CI] = [-2.52, 0.50]) as non-deployment-related pack-years (-0.83; [95% CI] = [-1.26, -0.50] for FEV1%-predicted; -0.52; [95% CI] = [-0.73, -0.36] for FEV1/FVC%-predicted). CONCLUSIONS: Although cumulative pack-years smoking was modest in this cohort, an inverse association with pulmonary function was detectable. Deployment-related pack-years had a similar association with pulmonary function compared to non-deployment-related pack-years.

Knowledge Gaps and Research Priorities in Immune Checkpoint Inhibitor-related Pneumonitis. An Official American Thoracic Society Research Statement.

Rationale: Immune checkpoint inhibitors (ICIs) have revolutionized cancer care but are associated with unique adverse events, including potentially life-threatening pneumonitis. The diagnosis of ICI-pneumonitis is increasing; however, the biological mechanisms, clinical and radiologic features, and the diagnosis and management have not been well defined.Objectives: To summarize evidence, identify knowledge and research gaps, and prioritize topics and propose methods for future research on ICI-pneumonitis.Methods: A multidisciplinary group of international clinical researchers reviewed available data on ICI-pneumonitis to develop and refine research questions pertaining to ICI-pneumonitis.Results: This statement identifies gaps in knowledge and develops potential research questions to further expand knowledge regarding risk, biologic mechanisms, clinical and radiologic presentation, and management of ICI-pneumonitis.Conclusions: Gaps in knowledge of the basic biological mechanisms of ICI-pneumonitis, coupled with a precipitous increase in the use of ICIs alone or combined with other therapies, highlight the importance in triaging research priorities for ICI-pneumonitis.

Lung carcinoma progression and survival versus amino- and carboxyl-parathyroid hormone-related protein expression.

PURPOSE: Expression of the carboxyl PTHrP region of parathyroid hormone-related protein (PTHrP) is a positive prognostic indicator in women with lung cancer, but amino PTHrP is a negative indicator in other lung cancer patients. This project investigated whether PTHrP could be expressed as predominantly amino PTHrP or carboxyl PTHrP in individual lung carcinomas. It also assessed domain-specific effects on cancer progression and patient survival. METHODS: PTHrP immunoreactivities were analyzed versus survival in a human lung cancer tissue microarray (TMA). Growth was compared in athymic mice for isogenic lung carcinoma xenografts differing in expression of amino and carboxyl PTHrP domains. RESULTS: In the TMA, 33 of 99 patient tumors expressed only one PTHrP domain, while 54 expressed both. By Cox regression, the hazard ratio for cancer-specific mortality (95% confidence interval) was 2.6 (1.28-5.44) for amino PTHrP (P = 0.008) and 0.6 (0-2.58) for carboxyl PTHrP (P = 0.092). Xenografts of H358 lung adenocarcinoma cells that overexpressed amino PTHrP grew twice as fast as isogenic low PTHrP tumors in athymic mice, but growth of tumors expressing amino plus carboxyl PTHrP was not significantly different than growth of the control tumors. In summary, the presence of amino PTHrP signifies worse prognosis in lung cancer patients. In mouse xenografts, this effect was abrogated if carboxyl PTHrP was also present. CONCLUSION: Amino PTHrP and carboxyl PTHrP can vary independently in different lung carcinomas. Carboxyl PTHrP may temper the stimulatory effect of amino PTHrP on cancer progression.

Parathyroid-hormone-related protein signaling mechanisms in lung carcinoma growth inhibition.

Parathyroid hormone-related protein (PTHrP) inhibits proliferation of several lung cancer cell lines, but the signaling mechanism has not been established. This study tested the hypotheses that growth inhibition is mediated through the PTHrP receptor, PTH1R, and that the process is modified by ERK activation. PTHrP-positive and negative clones of H1944 lung adenocarcinoma cells underwent stable PTH1R knockdown with lentiviral shRNA or transient transfection with ERK1 and ERK2 siRNA. Alternatively, cells were treated with 8-CPT cAMP, 8-CPT 2'-O-methyl cAMP, and N-6-phenyl cAMP analogs. H1944 cells expressing ectopic PTHrP showed 20-40% decrease in proliferation compared to the PTHrP-negative cells in the presence of normal levels of PTH1R (P < 0.01). PTH1R knockdown eliminated this difference and increased cell proliferation regardless of PTHrP status. The three cAMP analogs each inhibited proliferation over 5 days by 30-40%. ERK2 knockdown inhibited proliferation of PTHrP-positive cells alone and in combination with ERK1 knockdown. The growth inhibition mediated by cAMP analogs was unaffected by ERK1 knockdown. In conclusion, ectopic expression of PTHrP 1-87 inhibits H1944 cell proliferation. PTH1R knockdown blocks this effect and stimulates proliferation, indicating that the ligand exerts anti-mitogenic effects. cAMP, the second messenger for PTH1R also inhibits proliferation and activates ERK. PTHrP growth inhibition may be opposed by concomitant ERK activation.

Prognostic implications of parathyroid hormone-related protein in males and females with non--small-cell lung cancer.

BACKGROUND: Non-small-cell lung carcinoma immunoreactivity for parathyroid hormone-related protein has been associated with increased survival in female patients but not in male patients. The current investigation attempted to substantiate this finding in 2 new patient groups. METHODS: Patients were divided into groups with and without immunoreactivity for a carboxyl-terminal parathyroid hormone-related protein epitope assessed in deparaffinized sections by a blinded observer. One group included 85 female patients with stage I lung cancer, and the second group had 48 female and 66 male patients with stage I-IV lung cancer. Survival times were compared by the log-rank test between groups separated by tumor parathyroid hormone-related protein status. RESULTS: Parathyroid hormone-related protein was present in 70%-80% of the patients, independent of sex, stage, and smoking history. In the females with stage I lung cancer, parathyroid hormone-related protein increased median survival from 25 to 60 months (P < .05). In the second group, parathyroid hormone-related protein expression increased 48-month disease-free survival of female lung cancer patients from 44% to 63% (P < .05), but had no effect in male patients. Parathyroid hormone-related protein remained a significant, independent predictor when evaluated together with other covariates by Cox multivariate regression. CONCLUSION: This study verifies that parathyroid hormone-related protein is a sex-dependent survival factor for non-small-cell lung carcinoma, that it correlates with disease-free survival, and that the association with survival holds for women with early-stage disease as well as more advanced cancer. Thus, the protein could find use as a prognostic indicator and could be a target for therapy.

Combinatorial library discovery of small molecule inhibitors of lung cancer proliferation and parathyroid hormone-related protein expression.

PTHrP (parathyroid hormone-related protein) is abnormally expressed in a substantial majority of lung cancers, especially non-small cell lung cancers, and plays a key role in tumor progression. Thus, this oncoprotein could be a target for treating patients with lung cancer. This study screened combinatorial libraries of heterocyclic amines for inhibitory effects on PTHrP expression and cell proliferation. Two libraries of over 780,000 bis-cyclic thiourea and guanidine compounds each were tested in BEN lung carcinoma cells. The number of PTHrP inhibitors and the magnitude of the reduction in PTHrP were greater for thioureas. Selected lead thiourea compounds decreased cell PTHrP protein content in dose-dependent fashion, reduced relative abundance of PTHrP mRNA, decreased transcripts derived from the PTHrP P3 promoter and reduced activity of a full length PTHrP promoter luciferase construct. Similar effects on PTHrP mRNA were observed in A549 and H441 lung adenocarcinoma cells and in H727 lung carcinoid cells. However, the compounds only inhibited PTHrP protein levels in BEN cells and H727 cells. The compounds reduced the rate of cell proliferation in BEN cells and H727 cells, but not in lines that showed no inhibition of PTHrP protein. These results suggest that cyclic thiourea compounds inhibit PTHrP expression mediated by the P3 promoter, which is widely used in the majority of PTHrP-expressing cells, and that they may inhibit growth of lung cancer cells through the same mechanism. Further work will be necessary to investigate their mechanism for effects on growth of PTHrP-positive tumors in vivo.

Cell cycle actions of parathyroid hormone-related protein in non-small cell lung carcinoma.

Parathyroid hormone-related protein (PTHrP), a paraneoplastic protein expressed by two-thirds of human non-small cell lung cancers, has been reported to slow progression of lung carcinomas in mouse models and to lengthen survival of patients with lung cancer. This study investigated the effects of ectopic expression of PTHrP on proliferation and cell cycle progression of two human lung adenocarcinoma cell lines that are normally PTHrP negative. Stable transfection with PTHrP decreased H1944 cell DNA synthesis, measured by thymidine incorporation, bromodeoxyuridine uptake, and MTT proliferation assay. A substantial fraction of PTHrP-positive cells was arrested in or slowly progressing through G1. Cyclin D2 and cyclin A2 protein levels were 60-70% lower in PTHrP-expressing cells compared with control cells (P < 0.05, N = 3 independent clones per group), while expression of p27(Kip1), a cyclin-dependent kinase inhibitor, was increased by 35 +/- 9% (mean +/- SE, P < 0.05) in the presence of PTHrP. Expression of other cyclins, including cyclins D1 and D3, and cyclin-dependent kinases was unaffected by PTHrP. PTHrP did not alter the phosphorylation state of Rb, but decreased cyclin-dependent kinase (CDK) 2-cyclin A2 complex formation. Ectopic expression of PTHrP stimulated ERK phosphorylation. In MV522 cells, PTHrP had similar effects on DNA synthesis, cyclin A2 expression, pRb levels, CDK2-cyclin A2 association, and ERK activation. In summary, PTHrP appears to slow progression of lung cancer cells into S phase, possibly by decreasing activation of CDK2. Slower cancer cell proliferation could contribute to slower tumor progression and increased survival of patients with PTHrP-positive lung cancer.

Parathyroid hormone-related protein varies with sex and androgen status in nonsmall cell lung cancer.

BACKGROUND: In nonsmall cell lung cancer, tumor parathyroid hormone-related protein (PTHrP) expression predicts longer survival in women but not in men. To explain the sex-dependent survival effect, the authors proposed that hormonal influences decrease PTHrP in men versus women, that PTHrP inhibits tumor growth, and that the effect is greater in women than in men. The objectives of this study were to compare lung carcinoma PTHrP expression and carcinoma growth in male and female mice and to determine whether gonadal steroids regulate PTHrP in lung cancer cells. METHODS: Tumor PTHrP content was measured by immunoassay, and tumor burden was assessed with multiple measures in BEN squamous cell orthotopic lung carcinomas in athymic mice. In addition, lung adenocarcinoma PTHrP messenger RNA (mRNA) values determined by microarray analyses were compared between men and women. Cultured lung cancer cells were assayed for PTHrP after treatment with estradiol or R1881, a synthetic androgen. RESULTS: Lung carcinomas contained approximately 3 times more PTHrP in female mice than in male mice. Similarly, levels of PTHrP mRNA were significantly greater in adenocarcinomas from patients who were women than from patients who were men. Male mice had greater tumor burden than female mice. Androgen treatment reduced PTHrP in 3 lung cancer lines. Estradiol had no effect. Testosterone treatment also reduced lung carcinoma PTHrP in female mice. CONCLUSIONS: Lung carcinomas in females expressed more PTHrP than in males possibly because of negative regulation by androgens in males. Female mice with higher tumor PTHrP content had significantly less tumor burden than male mice, supporting the hypothesis that PTHrP inhibits tumor growth.