Lung Cancer Pathogenesis Associated With Wood Smoke Exposure

Controlled human exposures: a review and comparison of the health effects of diesel exhaust and wood smoke

One of the most pressing issues in global health is air pollution. Emissions from traffic-related air pollution and biomass burning are two of the most common sources of air pollution. Diesel exhaust (DE) and wood smoke (WS) have been used as models of these pollutant sources in controlled human exposure (CHE) experiments. The aim of this review was to compare the health effects of DE and WS using results obtained from CHE studies. A total of 119 CHE-DE publications and 25 CHE-WS publications were identified for review. CHE studies of DE generally involved shorter exposure durations and lower particulate matter concentrations, and demonstrated more potent dysfunctional outcomes than CHE studies of WS. In the airways, DE induces neutrophilic inflammation and increases airway hyperresponsiveness, but the effects of WS are unclear. There is strong evidence that DE provokes systemic oxidative stress and inflammation, but less evidence exists for WS. Exposure to DE was more prothrombotic than WS. DE generally increased cardiovascular dysfunction, but limited evidence is available for WS. Substantial heterogeneity in experimental methodology limited the comparison between studies. In many areas, outcomes of WS exposures tended to trend in similar directions to those of DE, suggesting that the effects of DE exposure may be useful for inferring possible responses to WS. However, several gaps in the literature were identified, predominantly pertaining to elucidating the effects of WS exposure. Future studies should strongly consider performing head-to-head comparisons between DE and WS using a CHE design to determine the differential effects of these exposures.

Indoor wood-burning from stoves and fireplaces and incident lung cancer among Sister Study participants

BACKGROUND AND AIM

Epidemiological studies conducted mostly in low- and middle-income countries have found a positive association between household combustion of wood and lung cancer. However, most studies have been retrospective, and few have been conducted in the United States where indoor wood-burning usage patterns differ. We examined the association of exposure to indoor wood smoke from fireplaces and stoves with incident lung cancer in a U.S.-wide cohort of women.

METHODS

We included 50,226 women without prior lung cancer participating in the U.S.-based prospective Sister Study. At enrollment (2003-2009), women reported frequency of use of wood-burning stoves and/or fireplaces in their longest-lived adult residence. Cox regression was used to estimate adjusted hazard ratios (HRadj) and 95 % confidence intervals (CI) for the association between indoor wood-burning fireplace/stove use and incident lung cancer. Lung cancer was self-reported and confirmed with medical records.

RESULTS

During an average 11.3 years of follow-up, 347 medically confirmed lung cancer cases accrued. Overall, 62.3 % of the study population reported the presence of an indoor wood-burning fireplace/stove at their longest-lived adult residence and 20.6 % reported annual usage of ≥30 days/year. Compared to those without a wood-burning fireplace/stove, women who used their wood-burning fireplace/stove ≥30 days/year had an elevated rate of lung cancer (HRadj = 1.68; 95 % CI = 1.27, 2.20). In never smokers, positive associations were seen for use 1-29 days/year (HRadj = 1.64; 95 % CI = 0.87, 3.10) and ≥30 days/year (HRadj = 1.99; 95 % CI = 1.02, 3.89). Associations were also elevated across all income groups, in Northeastern, Western or Midwestern U.S. regions, and among those who lived in urban or rural/small town settings.

CONCLUSIONS

Our prospective analysis of a cohort of U.S. women found that increasing frequency of wood-burning indoor fireplace/stove usage was associated with incident lung cancer, even among never smokers.

Cancer Epidemiology in the Northeastern United States (2013-2017)

We tested the hypotheses that adult cancer incidence and mortality in the Northeast region and in Northern New England (NNE) were different than the rest of the United States, and described other related cancer metrics and risk factor prevalence. Using national, publicly available cancer registry data, we compared cancer incidence and mortality in the Northeast region with the United States and NNE with the United States overall and by race/ethnicity, using age-standardized cancer incidence and rate ratios (RR). Compared with the United States, age-adjusted cancer incidence in adults of all races combined was higher in the Northeast (RR, 1.07; 95% confidence interval [CI] 1.07-1.08) and in NNE (RR 1.06; CI 1.05-1.07). However compared with the United States, mortality was lower in the Northeast (RR, 0.98; CI 0.98-0.98) but higher in NNE (RR, 1.05; CI 1.03-1.06). Mortality in NNE was higher than the United States for cancers of the brain (RR, 1.16; CI 1.07-1.26), uterus (RR, 1.32; CI 1.14-1.52), esophagus (RR, 1.36; CI 1.26-1.47), lung (RR, 1.12; CI 1.09-1.15), bladder (RR, 1.23; CI 1.14-1.33), and melanoma (RR, 1.13; CI 1.01-1.27). Significantly higher overall cancer incidence was seen in the Northeast than the United States in all race/ethnicity subgroups except Native American/Alaska Natives (RR, 0.68; CI 0.64-0.72). In conclusion, NNE has higher cancer incidence and mortality than the United States, a pattern that contrasts with the Northeast region, which has lower cancer mortality overall than the United States despite higher incidence.

Significance

These findings highlight the need to identify the causes of higher cancer incidence in the Northeast and the excess cancer mortality in NNE.

Matrix Metalloproteinases and Stress Hormones in Lung Cancer Progression

Several matrix metalloproteinases (MMPs) and psychological stress are associated with poor cancer prognosis. The current work goal was to determine MMPs' and stress hormones' blood concentrations from lung adenocarcinoma (LAC) patients. Patients were divided into the following groups: tobacco smokers (TS), wood smoke-exposed (W), passive smokers (PS), TS exposed to wood smoke (TW), and patients with no recognizable risk factor (N). MMPs, tissue inhibitors of metalloproteinases (TIMPs), adrenaline, noradrenaline, and cortisol blood concentrations were measured by ELISA. Zymography and Western blot assays were performed to determine MMP-2 and MMP-9 active and latent forms. MMP-2, MMP-3, MMP-9, and TIMP-1 blood concentrations, and MMP-9 gelatinase activity were augmented, while MMP-12, MMP-14, and TIMP-2 were diminished in LAC patients. Cortisol was increased in LAC samples. Adrenaline concentrations were higher in W, TS, and TW, and noradrenaline was increased in W and N groups. Positive correlations were observed among cortisol and TIMP-1 (r s = 0.392) and TIMP-2 (r s = 0.409) in the W group and between noradrenaline and MMP-2 (r s = 0.391) in the N group. MMPs' blood concentration increments can be considered as lung cancer progression markers. Although stress hormones were also augmented, only weak correlations were observed between them and MMPs and TIMPs.

The impact of industrialization on malignant neoplastic disease of bone in England: A study of medieval and industrial samples

OBJECTIVE

The increasing prevalence of malignant disease has been associated with shifts in environmental, socioeconomic, and lifestyle risk factors as well as increased adult lifespan. We examine the relationship between malignant neoplasms affecting bone, age and industrialization.

MATERIALS

Pre-existing skeletal data from 11 medieval (1066-1547, n = 8973) and 14 industrial (1700-1890, n = 4748) cemeteries (N = 13,721) from England.

METHODS

Context number, sex, age-at-death, evidence of skeletal malignancy, and diagnosis were collated. The data were compared using chi square, Kolmogorov-Smirnov tests and logistic regression (α = 0.01).

RESULTS

There was a statistically significant increase in skeletal malignancy from 0.06 % in the medieval sample to 0.36 in the industrial sample (p < 0.001). Age had a strong relationship with malignancy (p = 0.003), sex did not (p = 0.464). Logistic regression revealed that time-period (p < 0.001) was a stronger predictor of skeletal malignancy than age-at-death (p = 0.002).

CONCLUSION

Our results confirm that even with the temporal increase in adult human lifespan the increase of malignant neoplasms of bone between the medieval and industrial time periods is still statistically significant.

SIGNIFICANCE

The augmented exposure to carcinogens and pollution during the Industrial Revolution had a strong effect on an individual's susceptibility to developing malignant disease of bone.

LIMITATIONS

This meta-analysis relies upon previously gathered data and diagnosis from a large number of researchers and did not include radiographic or CT screening. Only malignant neoplasms that affected bone could be included.

SUGGESTIONS FOR FURTHER RESEARCH

Increasing excavation and analysis of post-medieval cemeteries will provide more data. Multimethod approaches (radiography, CT, Micro-CT and histology) are encouraged.

Chemotherapy- and Immune-Related Gene Panel in Prognosis Prediction and Immune Microenvironment of SCLC

Small-cell lung cancer (SCLC) is a highly proliferative, invasive lung cancer with poor prognosis. Chemotherapy is still the standard first-line treatment for SCLC, but many patients relapse due to chemoresistance. Along with advances in immunology, it is essential to investigate potential indicators of the immune response and the prognosis of SCLC. Using bioinformatics analysis, we identified 313 differentially expressed genes (DEGs) in SCLC and normal lung samples, and we found that four upregulated genes (TOP2A, CDKN2A, BIRC5, and MSH2) were associated with platinum resistance, while immune-related genes (HLA family genes) were downregulated in SCLC. Then, a prognostic prediction model was constructed for SCLC based on those genes. Immune cell infiltration analysis showed that antigen presentation was weak in SCLC, and TOP2A expression was negatively correlated with CD8+ T cells, while HLA-ABC expression was positively correlated with M1 macrophages, memory B cells, and CD8+ T cells. We also found that TOP2A was related to poor prognosis and inversely correlated with HLA-ABC, which was verified with immunohistochemical staining in 151 SCLC specimens. Our study findings indicated that TOP2A may be a potential prognosis indicator and a target to reverse the immunosuppressive tumor microenvironment of SCLC.

Failure to EGFR-TKI-based therapy and tumoural progression are promoted by MEOX2/GLI1-mediated epigenetic regulation of EGFR in the human lung cancer

BACKGROUND

Mesenchyme homeobox-2 (MEOX2)-mediated regulation of glioma-associated oncogene-1 (GLI1) has been associated with poor overall survival, conferring chemoresistance in lung cancer. However, the role of MEOX2/GLI1 in resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs)-based therapy remains unexplored in human lung cancer.

METHODS

Functional assays using genetic silencing strategy by short hairpin RNAs, as well as cytotoxic (tetrazolium dye MTT) and clonogenic assays, were performed to evaluate MEOX2/GLI1-induced malignancy capacity in lung cancer cells. Further analysis performed includes western blot, qPCR and ChIP-qPCR assays to identify whether MEOX2/GLI1 promote EGFR/AKT/ERK activation, as well as EGFR overexpression through epigenetic mechanisms. Finally, preclinical tumour progression in vivo and progression-free disease interval analyses in patients treated with EGFR-TKI were included.

RESULTS

Overexpressed MEOX2/GLI1 in both EGFR wild-type and EGFR/KRAS-mutated lung cancer cells were detected and involved in the activation/expression of EGFR/AKT/ERK biomarkers. In addition, MEOX2/GLI1 was shown to be involved in the increased proliferation of tumour cells and resistance capacity to cisplatin, EGFR-TKIs (erlotinib and AZD9291 'osimertinib'), AZD8542-SMO, and AZD6244-MEKK1/2. In addition, we identified that MEOX2/GLI1 promote lung tumour cells progression in vivo and are clinically associated with poorer progression-free disease intervals. Finally, both MEOX2 and GLI1 were detected to be epigenetically involved in EGFR expression by reducing both repressive markers polycomb-EZH2 and histone H3K27me3, but, particularly, increasing an activated histone profile H3K27Ac/H3K4me3 at EGFR-gene enhancer-promoter sequences that probably representing a novel EGFR-TKI-based therapy resistance mechanism.

CONCLUSION

MEOX2/GLI1 promote resistance to cisplatin and EGFR-TKI-based therapy in lung cancer cells, modulating EGFR/AKT/ERK signalling pathway activation, as well as inducing an aberrant epigenetic modulation of the EGFR-gene expression in human lung cancer.

An Overview of Lung Cancer in Women and the Impact of Estrogen in Lung Carcinogenesis and Lung Cancer Treatment

Lung cancer incidence and mortality have significantly increased in women worldwide. Lung adenocarcinoma is the most common form of lung cancer globally. This type of lung cancer shows differences by sex, including the mutational burden, behavior, clinical characteristics, and response to treatment. The effect of sex on lung cancer patients' survival is still controversial; however, lung adenocarcinoma is considered a different disease in women and men. Moreover, lung adenocarcinoma is strongly influenced by estrogen and is also different depending on the hormonal status of the patient. Young pre-menopausal women have been explored as an independent group. They presented in more advanced stages at diagnosis, exhibited more aggressive tumors, and showed poor survival compared to men and post-menopausal women, supporting the role of sex hormones in this pathology. Several reports indicate the estrogen's role in lung carcinogenesis and tumor progression. Thus, there are currently some clinical trials testing the efficacy of antihormonal therapy in lung cancer treatment. This mini review shows the updated data about lung cancer in women, its characteristics, the etiological factors that influence carcinogenesis, and the critical role of estrogen in lung cancer and treatment.

The effects of everyday-life exposure to polycyclic aromatic hydrocarbons on biological age indicators

BACKGROUND

Further knowledge on modifiable aging risk factors is required to mitigate the increasing burden of age-related diseases in a rapidly growing global demographic of elderly individuals. We explored the effect of everyday exposure to polycyclic aromatic hydrocarbons (PAHs), which are fundamental constituents of air pollution, on cellular biological aging. This was determined via the analysis of leukocyte telomere length (LTL), mitochondrial DNA copy number (LmtDNAcn), and by the formation of anti-benzo[a]pyrene diolepoxide (B[a]PDE-DNA) adducts.

METHODS

The study population consisted of 585 individuals living in North-East Italy. PAH exposure (diet, indoor activities, outdoor activities, traffic, and residential exposure) and smoking behavior were assessed by questionnaire and anti-B[a]PDE-DNA by high-performance-liquid-chromatography. LTL, LmtDNAcn and genetic polymorphisms [glutathione S-transferase M1 and T1 (GSTM1; GSTT1)] were measured by polymerase chain reaction. Structural equation modelling analysis evaluated these complex relationships.

RESULTS

Anti-B[a]PDE-DNA enhanced with PAH exposure (p = 0.005) and active smoking (p = 0.0001), whereas decreased with detoxifying GSTM1 (p = 0.021) and in females (p = 0.0001). Subsequently, LTL and LmtDNAcn reduced with anti-B[a]PDE-DNA (p = 0.028 and p = 0.018), particularly in males (p = 0.006 and p = 0.0001). Only LTL shortened with age (p = 0.001) while elongated with active smoking (p = 0.0001). Besides this, the most significant determinants of PAH exposure that raised anti-B[a]PDE-DNA were indoor and diet (p = 0.0001), the least was outdoor (p = 0.003).

CONCLUSION

New findings stemming from our study suggest that certain preventable everyday life exposures to PAHs reduce LTL and LmtDNAcn. In particular, the clear association with indoor activities, diet, and gender opens new perspectives for tailored preventive measures in age-related diseases.

CAPSULE

Everyday life exposure to polycyclic aromatic hydrocarbons reduces leukocyte telomere length and mitochondrial DNA copy number through anti-B[a]PDE-DNA adduct formation.

Wood smoke black carbon from Indigenous traditional cultural activities in a subarctic Cree community

Indoor concentrations of black carbon (BC) were measured when wood was burned for traditional cultural activities in a study in a Cree community located in subarctic Canada. The study also included an intervention using a propane-fuelled heater to mitigate in situ BC. Mass concentrations of BC were measured in a game-smoking tent for 39 days and in hunting cabins on the west coast of James Bay, Canada, for 8 days. Five-minute averaged BC mass concentration (N = 12,319) data were recorded and assessed using optimised noise-reduction averaging. Mean BC mass concentrations were lower in hunting cabins (mean = 8.25 micrograms per cubic metre (µg m⁻³)) and higher in the game-smoking tent (mean = 15.46 µg m⁻³). However, excessive BC peaks were recorded in the game-smoking tent (maximum = 3076.71 µg m⁻³) when the fire was stoked or loaded. The intervention with the propane heater in a hunting cabin yielded a 90% reduction in measured BC mass concentrations. We do not presume that exposure to BC is of concern in hunting cabins with appropriate wood-burning appliances that are well-sealed and vent outside. In game-smoking tents, we advise that persons take intermittent breaks outside of the tent for fresh air.

Long noncoding RNA PART1 promotes progression of non-small cell lung cancer cells via JAK-STAT signaling pathway

Non‐small cell lung cancer (NSCLC), the major type of lung cancer, becomes the greatest threat to the life of people. Growing evidence shows prostate androgen‐regulated transcript 1 (PART1) is considered as effective markers for prostate cancer, and has been shown to be associated with poor prognosis of NSCLC. However, the tumorigenic mechanism of PART1 in NSCLC remains to be investigated. In this study, we found that the expression of PART1 was robustly induced in NSCLC tissues and cell lines. Functional studies established that overexpression of PART1 could promote NSCLC cell proliferation, migration, and invasion, while interference of PART1 inhibited NSCLC progression. Our results also identified miR‐635 as a novel target of PART1, whose expression was inhibited by PART1 in NSCLC cell lines. Moreover, gain‐ and loss‐of‐function studies revealed that PART1 could sponge miR‐635 and increase the expression of Janus kinase (JAK) and signal transducer and activator of transcription proteins (STATs). Finally, we deciphered the molecular mechanism by which PART1 contributed to promotion of NSCLC cell progression via phosphorylation and activation of JAK‐STAT signaling pathway. The animal experiment further confirmed that interference of NSCLC could suppress in vivo tumorigenic ability of NSCLC with favorable pharmacological activity via inactivation of JAK‐STAT signaling pathway. In conclusion, our findings clarified the biologic significance of PART1/miR‐635/JAK‐STAT axis in NSCLC progression and provided novel evidence that PART1 may be a new potential therapeutic target for the treatment of NSCLC.

JNK1/2 represses Lkb1-deficiency-induced lung squamous cell carcinoma progression

Mechanisms of lung squamous cell carcinoma (LSCC) development are poorly understood. Here, we report that JNK1/2 activities attenuate Lkb1-deficiency-driven LSCC initiation and progression through repressing ΔNp63 signaling. In vivo Lkb1 ablation alone is sufficient to induce LSCC development by reducing MKK7 levels and JNK1/2 activities, independent of the AMPKα and mTOR pathways. JNK1/2 activities is positively regulated by MKK7 during LSCC development. Pharmaceutically elevated JNK1/2 activities abates Lkb1 dependent LSCC formation while compound mutations of Jnk1/2 and Lkb1 further accelerate LSCC progression. JNK1/2 is inactivated in a substantial proportion of human LSCC and JNK1/2 activities positively correlates with survival rates of lung, cervical and head and neck squamous cell carcinoma patients. These findings not only determine a suppressive role of the stress response regulators JNK1/2 on LSCC development by acting downstream of the key LSCC suppresser Lkb1, but also demonstrate activating JNK1/2 activities as a therapeutic approach against LSCC.

LKB1 is frequently mutated in lung squamous cell carcinomas. Here, the authors show that sole LKB1 depletion is sufficient to drive the development of this cancer, where downstream defective MKK7-JNK1/2 signalling activates the ∆Np63/p63 pathway to induce subsequent epithelial cells transformation and tumour progression.

ERS/ATS workshop report on respiratory health effects of household air pollution

Exposure to household air pollution (HAP) from solid fuel combustion affects almost half of the world population. Adverse respiratory outcomes such as respiratory infections, impaired lung growth and chronic obstructive pulmonary disease have been linked to HAP exposure. Solid fuel smoke is a heterogeneous mixture of various gases and particulates. Cell culture and animal studies with controlled exposure conditions and genetic homogeneity provide important insights into HAP mechanisms. Impaired bacterial phagocytosis in exposed human alveolar macrophages possibly mediates several HAP-related health effects. Lung pathological findings in HAP-exposed individuals demonstrate greater small airways fibrosis and less emphysema compared with cigarette smokers. Field studies using questionnaires, air pollution monitoring and/or biomarkers are needed to better establish human risks. Some, but not all, studies suggest that improving cookstove efficiency or venting emissions may be associated with reduced respiratory symptoms, lung function decline in women and severe pneumonia in children. Current studies focus on fuel switching, stove technology replacements or upgrades and air filter devices. Several governments have initiated major programmes to accelerate the upgrade from solid fuels to clean fuels, particularly liquid petroleum gas, which provides research opportunities for the respiratory health community.

Epigenomic study identifies a novel mesenchyme homeobox2-GLI1 transcription axis involved in cancer drug resistance, overall survival and therapy prognosis in lung cancer patients

Several homeobox-related gene (HOX) transcription factors such as mesenchyme HOX-2 (MEOX2) have previously been associated with cancer drug resistance, malignant progression and/or clinical prognostic responses in lung cancer patients; however, the mechanisms involved in these responses have yet to be elucidated. Here, an epigenomic strategy was implemented to identify novel MEOX2 gene promoter transcription targets and propose a new molecular mechanism underlying lung cancer drug resistance and poor clinical prognosis. Chromatin immunoprecipitation (ChIP) assays derived from non-small cell lung carcinomas (NSCLC) hybridized on gene promoter tiling arrays and bioinformatics analyses were performed, and quantitative, functional and clinical validation were also carried out. We statistically identified a common profile consisting of 78 gene promoter targets, including Hedgehog-GLI1 gene promoter sequences (FDR≤0.1 and FDR≤0.2). The GLI-1 gene promoter region from -2,192 to -109 was occupied by MEOX2, accompanied by transcriptionally active RNA Pol II and was epigenetically linked to the active histones H3K27Ac and H3K4me3; these associations were quantitatively validated. Moreover, siRNA genetic silencing assays identified a MEOX2-GLI1 axis involved in cellular cytotoxic resistance to cisplatinum in a dose-dependent manner, as well as cellular migration and proliferation. Finally, Kaplan-Maier survival analyses identified significant MEOX2-dependent GLI-1 protein expression associated with clinical progression and poorer overall survival using an independent cohort of NSCLC patients undergoing platinum-based oncological therapy with both epidermal growth factor receptor (EGFR)-non-mutated and EGFR-mutated status. In conclusion, this is the first study to investigate epigenome-wide MEOX2-transcription factor occupation identifying a novel overexpressed MEOX2-GLI1 axis and its clinical association with platinum-based cancer drug resistance and EGFR-tyrosine kinase inhibitor (TKI)-based therapy responses in NSCLC patients.

Gene-expression profiles in lung adenocarcinomas related to chronic wood smoke or tobacco exposure

BACKGROUND

Tobacco-smoke is the major etiological factor related to lung cancer. However, other important factor is chronic wood smoke exposure (WSE). Approximately 30 % of lung cancer patients in Mexico have a history of WSE, and present different clinical, pathological and molecular characteristics compared to tobacco related lung cancer, including differences in mutational profiles. There are several molecular alterations identified in WSE associated lung cancer, however most studies have focused on the analysis of changes in several pathogenesis related proteins.

METHODS

Our group evaluated gene expression profiles of primary lung adenocarcinoma, from patients with history of WSE or tobacco exposure. Differential expression between these two groups were studied through gene expression microarrays.

RESULTS

Results of the gene expression profiling revealed 57 statistically significant genes (p < 0.01). The associated biological functional pathways included: lipid metabolism, biochemistry of small molecules, molecular transport, cell morphology, function and maintenance. A highlight of our analysis is that three of the main functional networks represent 37 differentially expressed genes out of the 57 found. These hubs are related with ubiquitin C, GABA(A) receptor-associated like protein; and the PI3K/AKT and MEK/ERK signaling pathways.

CONCLUSION

Our results reflect the intrinsic biology that sustains the development of adenocarcinoma related to WSE and show that there is a different gene expression profile of WSE associated lung adenocarcinoma compared to tobacco exposure, suggesting that they arise through different carcinogenic mechanisms, which may explain the clinical and mutation profile divergences between both lung adenocarcinomas.

Different mutation profiles and clinical characteristics among Hispanic patients with non-small cell lung cancer could explain the "Hispanic paradox"

OBJECTIVE

Sixteen percent of US population is Hispanic, mostly Mexican. Recently, two independent American reports demonstrated a higher overall survival (OS) in Hispanic populations compared with non-Hispanic-white populations (NHW) with non-small-cell lung cancer (NSCLC), even when most Hispanic patients are diagnosed at advanced disease stages and have lower income status. We analyzed the clinical, pathological, and molecular characteristics as well as outcomes in a cohort of NSCLC Hispanic patients from the National Cancer Institute of Mexico that could explain this "Hispanic Paradox".

MATERIAL AND METHODS

A cohort of 1260 consecutive NSCLC patients treated at the National Cancer Institute of Mexico from 2007 to 2014 was analyzed. Their clinical-pathological characteristics, the presence of EGFR and KRAS mutations and the prognosis were evaluated.

RESULTS

Patients presented with disease stages II, IIIa, IIIb and IV at rates of 0.6, 4.8, 18.4 and 76.3%, respectively. NSCLC was associated with smoking in only 56.5% of the patients (76.7% of male vs. 33.0% of female patients). Wood smoke exposure (WSE) was associated with 37.2% of the cases (27.3% in men vs. 48.8% in women). The frequency of EGFR mutations was 27.0% (18.5% in males vs. 36.9% in females, p<0.001) and the frequency for KRAS mutations was 10.5% (10.3% men vs. 10.1% in women p=0.939). The median OS for all patients was 23.0 [95% CI 19.4-26.2], whereas for patients at stage IV, it was 18.5 months [95% CI 15.2-21.8]. The independent factors associated with the OS were the ECOG, disease stage, EGFR and KRAS mutation status.

CONCLUSION

The high frequency of EGFR mutations and low frequency of KRAS mutations in Hispanic populations and different prevalence in lung cancer-related-developing risk factors compared with Caucasian populations, such as the lower frequency of smoking exposure and higher WSE, particularly in women, might explain the prognosis differences between foreign-born-Hispanics, US-born-Hispanics and NHWs.

Increased oxidative DNA damage and decreased expression of base excision repair proteins in airway epithelial cells of women who cook with biomass fuels

To investigate whether biomass burning causes oxidative DNA damage and alters the expression of DNA base excision repair (BER) proteins in airway cells, sputum samples were collected from 80 premenopausal rural biomass-users and 70 age-matched control women who cooked with liquefied petroleum gas. Compared with control the airway cells of biomass-users showed increased DNA damage in alkaline comet assay. Biomass-users showed higher percentage of cells expressing oxidative DNA damage marker 8-oxoguanine and lower percentages of BER proteins OGG1 and APE1 by immunocytochemical staining. Reactive oxygen species (ROS) generation was doubled and level of superoxide dismutase was depleted significantly among biomass-users. The concentrations of particulate matters were higher in biomass-using households which positively correlated with ROS generation and negatively with BER proteins expressions. ROS generation was positively correlated with 8-oxoguanine and negatively with BER proteins suggesting cooking with biomass is a risk for genotoxicity among rural women in their child-bearing age.

On the antiquity of cancer: evidence for metastatic carcinoma in a young man from ancient Nubia (c. 1200 BC)

Cancer, one of the world’s leading causes of death today, remains almost absent relative to other pathological conditions, in the archaeological record, giving rise to the conclusion that the disease is mainly a product of modern living and increased longevity. This paper presents a male, young-adult individual from the archaeological site of Amara West in northern Sudan (c. 1200BC) displaying multiple, mainly osteolytic, lesions on the vertebrae, ribs, sternum, clavicles, scapulae, pelvis, and humeral and femoral heads. Following radiographic, microscopic and scanning electron microscopic (SEM) imaging of the lesions, and a consideration of differential diagnoses, a diagnosis of metastatic carcinoma secondary to an unknown soft tissue cancer is suggested. This represents the earliest complete example in the world of a human who suffered metastatic cancer to date. The study further draws its strength from modern analytical techniques applied to differential diagnoses and the fact that it is firmly rooted within a well-documented archaeological and historical context, thus providing new insights into the history and antiquity of the disease as well as its underlying causes and progression.

Lung cancer mutations and use of targeted agents in Hispanics

Hispanic/Latinos (H/L) are expected to grow to over 24% of the USA population by 2050 and lung cancer is the number one cause of cancer death among H/L men. Due to the information that is becoming available via genetic testing, lung cancer molecular profiling is allowing for increasing application of personalized lung cancer therapies. However, to benefit the most people, development of these therapies and genetic tests must include research on as many racial and ethnic groups as possible. The purpose of this review is to bring attention to the fact that the mutations driving lung cancer in H/Ls differ in frequency and nature relative to the non-Hispanic White (WNH) majority that dominate current databases and participate in clinical trials that test new therapies. Clinical trials using new agents targeting genetic alterations (driver mutations) in lung cancer have demonstrated significant improvements in patient outcomes (for example, gefitinib, erlotinib or crizotinib for lung adenocarcinomas harboring EGFR mutations or EML4-ALK fusions, respectively). The nature and frequencies of some lung cancer driver mutations have been shown to be considerably different among racial and ethnic groups. This is particularly true for H/Ls. For example, several reports suggest a dramatic shift in the mutation pattern from predominantly KRAS in a WNH population to predominantly EGFR in multiple H/L populations. However, these studies are limited, and the effects of racial and ethnic differences on the incidence of mutations in lung cancer remain incompletely understood. This review serves as a call to address this problem.

miR-150 promotes the proliferation of lung cancer cells by targeting P53

Lung cancer is one of the most common causes for cancer-related death. Previous studies suggested that uncontrolled cell proliferation induced by activation of pro-cancer genes or inhibition of cancer suppressor genes plays an important role in the pathogenesis of lung cancer. Here, we demonstrate that miR-150 is aberrantly upregulated in lung cancer tissue and negatively correlates with the expression of the proapoptotic gene p53 but not EGR2. We show that miR-150 specifically targets the 3'-UTR of p53 and regulates its expression. Inhibition of miR-150 effectively delays cell proliferation and promotes apoptosis, accompanied by increased p53 protein expression. Our data reveals the mechanisms underlying miR-150 regulated lung cancer pathogenesis, which might be beneficial for lung cancer therapy.

Indoor air contaminants and their impact on respiratory pathologies

Humans spend a considerable amount of their time breathing air inside enclosed spaces in which, due to various sources, there may be contaminants that deteriorate the air quality. This is an important risk factor for the health of the general population. This review evaluates the contaminants that are present in the air of indoor air spaces, describing the sources that generate them as well as the physiopathological mechanisms and the diseases that they may cause in the respiratory system.

Differences in plasma MMPs and TIMPs protein expression and chemotherapy response in patients with tobacco- or wood-smoke-induced lung cancer

BACKGROUND

One of the risk factors associated with lung cancer in never-smoker patients is wood smoke exposure (WS). However, information about its clinical and molecular characteristics remains scant.

OBJECTIVE

This was to analyze--in plasma from patients with tobacco- or wood-smoke-induced lung cancer--whether the enzymatic activity and concentration of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) differ, and to determine whether there was a correlation between these indicators of the metastatic potential and the first-line chemotherapy response.

METHODS

Patients were classified according to lung cancer associated with: the smoking of tobacco (T), WS and where no association with a known risk factor (N) could be established. The gelatinase activity of plasma MMP was analyzed by radiolabeled substrate degradation and zymography assay. Protein expression of MMPs and TIMPs was evaluated by Western blot densitometry analysis.

RESULTS

The 26.9% WS patients had a better response to therapy in comparison with the T group (OR = 4.9, 95% CI = 1.25-20.15; p = 0.019). The lowest gelatinase activity was observed in WS subjects, in comparison with T and N subjects (96.7 ± 15.9, 182.9 ± 31.5 and 163.3 ± 22.7 µg of degraded gelatin/mg of incubated plasma protein, respectively; p < 0.025); this enzymatic activity corresponded to MMP-2. The highest MMP-2, MMP-9, MT1-MMP and TIMP-1 plasma levels were observed in T subjects.

CONCLUSION

Tobacco and wood smoke have different effects on MMP and TIMP synthesis and gelatinase activity, directly influencing lung cancer metastatic potential and chemotherapy response.

Chronic inhalation of biomass smoke is associated with DNA damage in airway cells: involvement of particulate pollutants and benzene

This study examined whether indoor air pollution from biomass fuel burning induces DNA damage in airway cells. For this, sputum cells were collected from 56 premenopausal rural women who cooked with biomass (wood, dung, crop residues) and 49 age-matched controls who cooked with cleaner liquefied petroleum gas. The levels of particulate matters with diameters of less than 10 and 2.5 µm (PM(10) and PM(2.5)) in indoor air were measured using a real-time aerosol monitor. Benzene exposure was monitored by measuring trans,trans-muconic acid (t,t-MA) in urine by HPLC-UV. DNA damage was examined by alkaline comet assay in sputum cells. Generation of reactive oxygen species (ROS) and level of superoxide dismutase (SOD) in sputum cells were measured by flow cytometry and spectrophotometry, respectively. Compared with controls, biomass users had 4 times higher tail percentage DNA, 37% more comet tail length and 5 times more Olive tail moment (p < 0.001) in inflammatory and epithelial cells in sputum, suggesting extensive DNA damage. In addition, women who cooked with biomass had 6 times higher levels of urinary t,t-MA and 2-fold higher levels of ROS generation concomitant with 28% depletion of SOD. Indoor air of biomass-using households had 2-4 times more PM(10) and PM(2.5) than that of controls. After controlling potential confounders, positive association was found between DNA damage parameters, particulate pollution, urinary t,t-MA and ROS. Thus, long-term exposure to biomass smoke induces DNA damage in airway cells and the effect was probably mediated, at least in part, by oxidative stress generated by inhaled particulate matter and benzene.

Long-term exposure to biomass fuel and its relation to systolic and diastolic biventricular performance in addition to obstructive and restrictive lung diseases

BACKGROUND

Previous studies have demonstrated an increased risk for cardiovascular events and pulmonary disease in patients with biomass fuel exposure (BFE). However, biventricular heart function has yet to be investigated in these patients. Left ventricular (LV) myocardial performance index (LVMPI), which is an index of global ventricular function, incorporates ejection, isovolumic relaxation, and contraction times. In this study, pulmonary function and biventricular heart function were investigated in nonsmoking female patients with BFE.

METHODS

Our study population consisted of 46 female patients with BFE (group 1) and 31 control subjects (group 2). Pulmonary function tests and transthoracic echocardiographic examination were performed. Right ventricular myocardial performance index (RVMPI) and LVMPI were obtained by tissue Doppler imaging echocardiography (TDI).

RESULTS

BFE caused obstructive and restrictive spirometric impairments. RVMPI was higher in group 1 (0.55 ± 0.07) than group 2 (0.46 ± 0.06) (P = 0.042) and LVMPI was higher in group 1 (0.54 ± 0.08) than group 2 (0.47 ± 0.05) (P = 0.032). Also, pulmonary artery systolic pressure was higher in group 1 than group 2 (P = 0.02).

CONCLUSIONS

BFE causes both obstructive and/or restrictive lung disease and systolic and diastolic biventricular dysfunction. Nonetheless, long-term studies are needed to understand on BFE-related ventricular dysfunctions and to document subsequent cardiovascular events.

Indoor air pollution as a lung health hazard: focus on populous countries

PURPOSE OF REVIEW

Indoor air pollution (IAP) resulting from the use of solid fuel for cooking and heating is a significant public health concern in developing countries. Recent studies have attempted to better characterize the epidemiology of IAP in respiratory diseases and develop technologies for reducing this IAP exposure.

RECENT FINDINGS

Evidence showed that IAP resulting from solid fuel smoke is a causative or contributory factor to acute respiratory infection, chronic obstructive lung disease, asthma, lung cancer and tuberculosis. Evidence also showed that health education, improvements in household ventilation and area distribution, improvements in stoves and changes of the fuels for cooking and heating can reduce IAP.

SUMMARY

Evidence of impacts of IAP on respiratory system disease is strong. Although some technologies can improve indoor air quality in households, improving it in households is still an urgent and high-priority task. Longitudinal studies using different methods of exposure assessment that include both chemical measurements and activity data, with longer follow-up and larger samples, are needed. Any program for the prevention of IAP must be based on what is acceptable to the community, and the effects of the intervention must be evaluated.

Environmental risk factors for lung cancer in Iran: a case-control study

BACKGROUND

Lung cancer remains the leading cause of cancer death in the world. In Iran, lung cancer is one of the five leading tumours and its incidence has been increasing steadily in both men and women. There is a paucity of data from Iran on risk factors for lung cancer. We evaluated environmental risk factors for lung cancer in a case-control study in five hospitals of Tehran.

METHODS

Between October 2002 and October 2005, 242 (178 male, 64 female) patients with histologically confirmed lung cancer and two controls for each patient (242 hospital controls and 242 visiting healthy controls) matched for age, sex and place of residence were interviewed using a structured questionnaire on potential risk factors for lung cancer, including environmental and occupational exposures. Associations between risk factors and lung cancer were assessed using conditional logistic regression.

RESULTS

Smokers were 66.5% of all cases (85.4% of men and 14.1% of women) and smoking was the strongest correlate of lung cancer in multivariate analysis [odds ratio (OR) 5.4, 95% confidence interval (CI) 3.2-8.9]. Occupational exposures to inorganic dusts (OR 4.2, 95% CI 2.8-6.7), chemical compounds (OR = 3.4, 95% CI 2.1-5.6) and heavy metals (OR 3.0, 95% CI 1.3-7.0) were also independent risk factors for lung cancer.

CONCLUSIONS

In our study, smoking was the principal risk factor for lung cancer. However, preventable exposures in the environment, including occupational settings, should not be ignored.

Comparative study of respiratory symptoms and lung function alterations in patients with chronic obstructive pulmonary disease related to the exposure to wood and tobacco smoke

OBJECTIVE

To describe and analyze clinical symptoms and spirometric alterations of patients with chronic obstructive pulmonary disease (COPD) and history of exposure to wood and tobacco smoke.

METHODS

We retrospectively evaluated data related to 170 patients distributed into 3 groups: 34 exposed only to wood smoke, 59 patients exposed only to tobacco smoke and 77 patients exposed to both.

RESULTS

The groups did not differ significantly in terms of age (p = 0.225) or degree of exposure, considering each type of exposure in isolation or in combination (p = 0.164 and p = 0.220, respectively). Females predominated in the group exposed to wood smoke. There were no differences among the groups regarding respiratory symptoms (p > 0.05), and moderate dyspnea predominated in the three groups (p = 0.141). The group exposed to wood smoke presented higher percentages of forced expiratory volume in one second/forced vital capacity ratio and of forced expiratory volume in one second (p < 0.05). Positive results on bronchodilator testing occurred more frequently in the group exposed to tobacco smoke. The percentage of severe and extremely severe obstruction was significantly higher in the group exposed to tobacco smoke (44.1%) than in that exposed to wood smoke (11.8%; p = 0.006).

CONCLUSIONS

Respiratory symptoms and pulmonary function alterations consistent with COPD were observed in the groups of patients exposed to wood smoke. However, those alterations were not as significant as the alterations observed in the groups exposed to tobacco smoke. This study emphasizes the importance of prospective studies in evaluating the risk of wood-smoke-related COPD in Brazil, as well as the need for preventive measures in this area.

Health effects of subchronic exposure to environmental levels of hardwood smoke

Hardwood smoke is a contributor to both ambient and indoor air pollution. As part of a general health assessment of multiple anthropogenic source emissions conducted by the National Environmental Respiratory Center, a series of health assays was conducted on rodents exposed to environmentally relevant levels of hardwood smoke. This article summarizes the study design and exposures, and reports findings on general indicators of toxicity, bacterial clearance, cardiac function, and carcinogenic potential. Hardwood smoke was generated from an uncertified wood stove, burning wood of mixed oak species. Animals were exposed to clean air (control) or dilutions of whole emissions based on particulate (30, 100, 300, and 1000 micromg/m3). F344 rats, SHR rats, strain A/J mice, and C57BL/6 mice were exposed by whole-body inhalation 6 h/day, 7 days/wk, for either 1 wk or 6 mo. Effects of exposure on general indicators of toxicity, bacterial clearance, cardiac function, and carcinogenic potential were mild. Exposure-related effects included increases in platelets and decreases in blood urea nitrogen and serum alanine aminotransferase. Several other responses met screening criteria for significant exposure effects but were not consistent between genders or exposure times and were not corroborated by related parameters. Pulmonary histopathology revealed very little accumulation of hardwood smoke particulate matter. Parallel studies demonstrated mild exposure effects on bronchoalveolar lavage parameters and in a mouse model of asthma. In summary, the results reported here show few and only modest health hazards from short-term to subchronic exposures to realistic concentrations of hardwood smoke.

Oncogene and tumor-suppressor gene products as serum biomarkers in occupational-derived lung cancer

Since lung cancer is the most frequent occupational cancer and one of the leading causes of cancer mortality in the world, it is one of the biggest challenges for research. In the literature, there are inconsistent results regarding the utility of the serum biomarkers p53, anti-p53 antibodies, EGF receptor or Ras. Based on the published results, routine use of these biomarkers for detection of occupationally derived lung carcinomas is not currently recommended. In this review, we summarize the literature and discuss the relevance of these oncogene and tumor-suppressor gene products as serum biomarkers in occupational-derived lung cancer.

Determinants of anti-benzo[a]pyrene diol epoxide-DNA adduct formation in lymphomonocytes of the general population

We evaluated determinants of anti-benzo[a]pyrenediolepoxide-(B[a]PDE)-DNA adduct formation (adduct induced by the ultimate carcinogenic metabolite of B[a]P) in lymphomonocytes of subjects environmentally exposed to low doses of polycyclic aromatic hydrocarbons (PAHs) (B[a]P). Our study population consisted of 585 Caucasian subjects, all municipal workers living in North-East Italy and recruited during their periodic check-ups after informed consent. PAH (B[a]P) exposure was assessed by questionnaire. Anti-B[a]PDE-DNA levels were measured by HPLC fluorescence analysis. We found that cigarette smoking (smokers (22%) versus non-smokers, p<0.0001), dietary intake of PAH-rich meals (> or =52 (38%) versus <52 times/year, p<0.0001), and outdoor exposure (> or =4 (19%) versus <4h/day; p=0.0115) significantly influenced adduct levels. Indoor exposure significantly increased the frequency of positive subjects (> or =0.5 adducts/10(8) nucleotides; chi(2) for linear trend, p=0.051). In linear multiple regression analysis the major determinants of increased DNA adduct levels (ln values) were smoking (t=6.362, p<0.0001) and diet (t=4.035, p<0.0001). In this statistical analysis, indoor and outdoor exposure like other factors of PAH exposure had no influence. In non-smokers, the influence of diet (p<0.0001) and high indoor exposure (p=0.016) on anti-B[a]PDE-DNA adduct formation became more evident, but not that of outdoor exposure, as was confirmed by linear multiple regression analysis (diet, t=3.997, p<0.0001 and high indoor exposure, t=2.522, p=0.012). This study indicates that anti-B[a]PDE-DNA adducts can be detected in the general population and are modulated by PAH (B[a]P) exposure not only with smoking - information already known from studies with limited number of subjects - but also with dietary habits and high indoor exposure. In non-smokers, these two factors are the principal determinants of DNA adduct formation. The information provided here seems to be important, since DNA adduct formation in surrogate tissue is an index of genotoxic exposure also in target organs (e.g., lung) and their increase may also be predictive of higher risk for PAH-related cancers.

Survival of patients with chronic obstructive pulmonary disease due to biomass smoke and tobacco

RATIONALE

Women exposed chronically to biomass develop airflow limitation, as tobacco smokers do, but their clinical profile and survival have not been described in detail.

OBJECTIVE

To determine the clinical profile, survival, and prognostic factors of chronic obstructive pulmonary disease associated with biomass exposure and tobacco smoking.

METHODS

During a 7-yr period (1996-2003), a consecutive series of 520 patients were recruited and followed up at the COPD Clinic of the National Institute of Respiratory Diseases. Prognostic factors of survival were evaluated taking into account the interaction between sex and exposure.

MEASUREMENTS

Spirometry, arterial blood gases and oxygen saturation, body mass index, exercise capacity, and health-related quality of life were performed at baseline. The main outcome was survival.

MAIN RESULTS

A total of 481 patients were followed up. The patients in the biomass group, mainly women (84%), were older and shorter and had a greater body mass index than those in the tobacco group (p < 0.0001). Airflow obstruction was more severe in smokers (p < 0.001). Quality of life and distance walked showed similar abnormalities in both groups. In the multivariable Cox regression analysis including an interaction term exposure-sex, we found that age (relative risk [RR], 1.02; 95% confidence interval [CI], 1.02-1.07), FEV(1) as percentage of predicted (RR, 0.96; 95% CI, 0.96-0.99), body mass index (RR, 0.95; 95% CI, 0.90-1.01), and oxygen saturation (RR, 0.96; 95% CI, 0.92-0.99) were predictors of mortality but not exposure or sex.

CONCLUSIONS

Women exposed domestically to biomass develop chronic obstructive pulmonary disease with clinical characteristics, quality of life, and increased mortality similar in degree to that of tobacco smokers.