Lung cancer is mainly caused by smoking, but the quantitative relations between smoking and histologic subtypes of lung cancer remain inconclusive. By using one of the largest lung cancer datasets ...ever assembled, we explored the impact of smoking on risks of the major cell types of lung cancer. This pooled analysis included 13,169 cases and 16,010 controls from Europe and Canada. Studies with population controls comprised 66.5% of the subjects. Adenocarcinoma (AdCa) was the most prevalent subtype in never smokers and in women. Squamous cell carcinoma (SqCC) predominated in male smokers. Age‐adjusted odds ratios (ORs) were estimated with logistic regression. ORs were elevated for all metrics of exposure to cigarette smoke and were higher for SqCC and small cell lung cancer (SCLC) than for AdCa. Current male smokers with an average daily dose of >30 cigarettes had ORs of 103.5 (95% confidence interval (CI): 74.8–143.2) for SqCC, 111.3 (95% CI: 69.8–177.5) for SCLC and 21.9 (95% CI: 16.6–29.0) for AdCa. In women, the corresponding ORs were 62.7 (95% CI: 31.5–124.6), 108.6 (95% CI: 50.7–232.8) and 16.8 (95% CI: 9.2–30.6), respectively. Although ORs started to decline soon after quitting, they did not fully return to the baseline risk of never smokers even 35 years after cessation. The major result that smoking exerted a steeper risk gradient on SqCC and SCLC than on AdCa is in line with previous population data and biological understanding of lung cancer development.
The aim of this study was to evaluate platelet activation in gastric cancer patients with regard to histopathological classification and the presence of distant metastases, by using platelet ...morphological parameters: MPV, L-PLT, MPC, as well as quantitative evaluation of surface receptor expression: CD41a, CD61, CD42b, CD62P, by flow cytometry at the resting state and after TRAP activation. In gastric cancer patients higher values of MPV and LP, as well as decreased MPC values were determined. Quantitative evaluation of surface antigen expression also revealed higher number of CD41a, CD61 and CD62P molecules, as compared with the platelets in the control group. Significant decrease of CD42b molecules' number after TRAP incubation, and the increased CD41a, CD61 and CD62P expression also point to the retained reactivation capacity of platelets. Good correlation between morphological parameters and the number of CD62P molecules indicates the usefulness of routine tests in evaluation of platelet activation.
Diesel motor exhaust is classified by the International Agency for Research on Cancer as probably carcinogenic to humans. The epidemiologic evidence is evaluated as limited because most studies lack ...adequate control for potential confounders and only a few studies have reported on exposure-response relationships.
Investigate lung cancer risk associated with occupational exposure to diesel motor exhaust, while controlling for potential confounders.
The SYNERGY project pooled information on lifetime work histories and tobacco smoking from 13,304 cases and 16,282 controls from 11 case-control studies conducted in Europe and Canada. A general population job exposure matrix based on ISCO-68 occupational codes, assigning no, low, or high exposure to diesel motor exhaust, was applied to determine level of exposure.
Odds ratios of lung cancer and 95% confidence intervals were estimated by unconditional logistic regression, adjusted for age, sex, study, ever-employment in an occupation with established lung cancer risk, cigarette pack-years, and time-since-quitting smoking. Cumulative diesel exposure was associated with an increased lung cancer risk highest quartile versus unexposed (odds ratio 1.31; 95% confidence interval, 1.19-1.43), and a significant exposure-response relationship (P value < 0.01). Corresponding effect estimates were similar in workers never employed in occupations with established lung cancer risk, and in women and never-smokers, although not statistically significant.
Our results show a consistent association between occupational exposure to diesel motor exhaust and increased risk of lung cancer. This association is unlikely explained by bias or confounding, which we addressed by adjusted models and subgroup analyses.
Background
The role of human papillomavirus (HPV) in the causation of esophageal squamous cell carcinoma is unclear. We examined the associations between esophageal squamous cell carcinoma and 28 ...centrally measured HPV serological markers in serum from six existing case-control studies conducted in regions with differing background risks of esophageal cancer.
Methods
We used centralized multiplex serology to test serum samples from 1561 case subjects and 2502 control subjects from six case-control studies for antibodies to the major HPV capsid protein (L1) and/or the early proteins E6 and/or E7 of eight high-risk, two low-risk, and four cutaneous HPV types. Study-specific odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using conditional logistic regression with adjustment for smoking, alcohol consumption, and other potential confounders. Pooled odds ratios and 95% confidence intervals were calculated using either a linear mixed-effects approach or a joint fixed-effects approach. All statistical tests were two-sided.
Results
We found statistically significant associations between esophageal squamous cell carcinoma and antibodies to E6 for HPV16 (OR = 1.89, 95% CI = 1.09 to 3.29, P = .023) and HPV6 (OR = 2.53, 95% CI = 1.51 to 4.25, P < .001) but not for other tested HPV types. There were no statistically significant associations between esophageal squamous cell carcinoma and antibodies to E7 for any of the tested HPV types. Simultaneous seropositivity for HPV16 E6 and E7 was rare (four case subjects, two control subjects; OR = 5.57, 95% CI = 0.90 to 34.35; P = .064). We also found statistically significant associations between esophageal squamous cell carcinoma and capsid antibodies for the high-risk mucosal type HPV33 L1 (OR = 1.30, 95% CI = 1.00 to 1.69; P = .047) and the low-risk mucosal types HPV6 (OR = 1.22, 95% CI = 1.05 to 1.42; P = .010) and HPV11 (OR = 1.30, 95% CI = 1.09 to 1.56, P = .0036).
Conclusions
We found limited serological evidence of an association between esophageal squamous cell carcinoma and HPV in the populations studied. Although HPV does not appear to be an important risk factor for esophageal squamous cell carcinoma, we cannot exclude the possibility that certain HPV types may be involved in a small subset of cancers.
Little is known about the biochemical "machinery" responsible for the morphological features of apoptosis, although the cytoskeleton is presumed to be involved. Using flow cytometry, polyacrylamide ...gel electrophoresis, and fluorescence microscopy, we show that apoptosis induced by ultraviolet (UV) irradiation or 80 micrograms/ml etoposide correlates with early transient polymerization and later depolymerization of filamentous (F)-actin and dramatic changes in visible microfilament organization. Depolymerization of F-actin began before the formation of apoptotic bodies and was ultimately composed of decreases in both the detergent-insoluble (40%) and detergent-soluble (50%) pools of F-actin. Dihydrocytochalasin B (H2CB), which blocked apoptotic body formation, depolymerized F-actin in the detergent-insoluble pool only. Visually, H2CB treatment disrupted microfilament organization, resulting in short, brightly stained microfilaments dispersed throughout the cytoplasm. In contrast, apoptotic cells contained a network of fine microfilaments with bright staining concentrated at the site of apoptotic body formation. Together, these results suggest that reorganization of the microfilament network is necessary for the formation of apoptotic bodies and that depolymerization of F-actin may also be a necessary component of the process of apoptosis.
Cell death due to necrosis results in acute inflammation, while death by apoptosis generally does not. The effect of adenosine triphosphate (ATP) on the pattern of cell death induced by oxidants was ...examined in bovine endothelial cells. ATP levels were altered by hydrogen peroxide (H
2O
2), glutamine (Gln), and metabolic inhibition (MI), to determine if necrosis can be shifted to apoptosis during oxidant injury. The form of cell death was determined by fluorescence microscopic techniques and the pattern of DNA degradation on agarose gels. ATP levels were measured using the luciferase–luciferin assay. Apoptosis occurred with 100 μM H
2O
2 without an alteration in ATP levels. ATP was significantly lowered with 5 mM H
2O
2, and necrosis occurred. MI, in combination with 100 μM H
2O
2, decreased ATP and resulted in necrosis. MI alone, however, did not cause cell death. Gln partially restored ATP levels in cells injured with 5 mM H
2O
2 and resulted in a significant increase in apoptosis. DNA laddering on agarose gels confirmed the apoptotic changes seen by fluorescence microscopy. In summary, a threshold level of ATP 25% of basal levels is required for apoptosis to proceed after oxidant stress, otherwise necrosis occurs. Agents like glutamine that enhance ATP levels in oxidant-stressed cells may be potent means of shifting cell death during inflammation to the noninflammatory form of death—apoptosis.
Sulfur Mustard (SM) is a vesicant or blistering chemical warfare agent, for which there still is no effective therapy. Endothelial cells are one of the major cellular targets for SM. The mechanism of ...endothelial cell death during SM injury is poorly understood. We studied the effect of exposure of endothelial cells to 0–1000 μMSM over the time course of 2–24 hr to determine the role of apoptotic and necrotic patterns of cell death in endothelial injury induced by SM. SM concentrations ≤250 μMinduced exclusively apoptosis which was observed after 5 hr in 30% of endothelial cells. Exposure to SM concentrations ≥500 μMcaused apoptosis and necrosis to the same extent in 60–85% of all cells after 5 to 6 hr. Necrosis was accompanied by a significant (∼50%) depletion of intracellular ATP, while in apoptotic cells ATP remained at the level similar to healthy cells. Interestingly, disruption of the long actin filament stress fibers and rounding of cells preceded other features of apoptosis—DNA fragmentation, membrane budding, and apoptotic body formation. In apoptotic cells, microfilaments formed constricted perinuclear bands, which were not observed in necrotic cells. Pretreatment with 50 mMN-acetyl-L-cysteine (NAC), a sulfhydryl donor and antioxidant, nearly eliminated the apoptotic features of cell death but did not prevent necrosis in response to SM. NAC pretreatment alone induced reorganization of actin filaments into an enhanced network of long stress fibers instead of a dominant cortical band of actin. NAC pretreatment prevented loss of cell adherence and cell rounding following exposure to 250 μMSM. The effect of NAC on cytoskeletal organization and its ability to eliminate SM-induced apoptosis suggests that actin filament organization may be an important element in cellular susceptibility to apoptotic stimuli.
The Human Cell Atlas is a large international collaborative effort to map all cell types of the human body. Single-cell RNA sequencing can generate high-quality data for the delivery of such an ...atlas. However, delays between fresh sample collection and processing may lead to poor data and difficulties in experimental design.
This study assesses the effect of cold storage on fresh healthy spleen, esophagus, and lung from ≥ 5 donors over 72 h. We collect 240,000 high-quality single-cell transcriptomes with detailed cell type annotations and whole genome sequences of donors, enabling future eQTL studies. Our data provide a valuable resource for the study of these 3 organs and will allow cross-organ comparison of cell types. We see little effect of cold ischemic time on cell yield, total number of reads per cell, and other quality control metrics in any of the tissues within the first 24 h. However, we observe a decrease in the proportions of lung T cells at 72 h, higher percentage of mitochondrial reads, and increased contamination by background ambient RNA reads in the 72-h samples in the spleen, which is cell type specific.
In conclusion, we present robust protocols for tissue preservation for up to 24 h prior to scRNA-seq analysis. This greatly facilitates the logistics of sample collection for Human Cell Atlas or clinical studies since it increases the time frames for sample processing.
Elevated levels of reactive nitrogen species, alteration in redox balance and deregulated redox signaling are common hallmarks of cancer progression and chemoresistance. However, depending on the ...cellular context, distinct reactive nitrogen species are also hypothesized to mediate cytotoxic activity and are thus used in anticancer therapies. We present here the dual face of nitric oxide and its derivatives in cancer biology. Main derivatives of nitric oxide, such as nitrogen dioxide and peroxynitrite cause cell death by inducing protein and lipid peroxidation and/or DNA damage. Moreover, they control the activity of important protein players within the pro- and anti-apoptotic signaling pathways. Thus, the control of intracellular reactive nitrogen species may become a sophisticated tool in anticancer strategies.
•Nitric oxide derivatives mediate the cytotoxic effect of nitric oxide.•Post-translational modifications induced by nitric oxide derivatives regulate cancer cell death or survival.•Genotoxic effect of nitric oxide is mediated by nitric oxide derivatives.•Nitrated fatty acids as anticancer agents.•2-methoxyestradiol, metabolite of 17β-estradiol, is a intracellular inducer of nitro-oxidative stress in cancer cells.
Although endothelial cells and keratinocytes appear to be the primary cellular targets of sulfur mustard (SM), the role of the nuclear enzyme poly (ADP-ribose) polymerase (PARP) in SM-induced ...vesication has not been clearly defined. PARP is thought to play a crucial role in DNA repair mechanisms following exposure to alkylating agents like SM. Using a combination of fluorescence microscopy and biochemical assays, we tested the hypothesis that SM causes activation of PARP in endothelial cells and keratinocytes with subsequent loss of nicotinamide adenine dinucleotide (NAD) and depletion of adenosine triphosphate (ATP) levels. To determine if PARP activation accounts for SM-induced vesication, keratinocyte adherence and permeability of endothelial monolayers were measured as in vitro correlates of vesication. As early as 2 to 3 h after exposure to SM concentrations as low as 250 microM, dramatic changes were induced in keratinocyte morphology and microfilament architecture. Exposure to 500 microM SM induced a fourfold increase in PARP activity in endothelial cells, and a two- to threefold increase in keratinocytes. SM induced a dose-related loss of NAD+ in both endothelial cells and keratinocytes. ATP levels fell to approximately 50% of control levels in response to SM concentrations >/=500 microM. SM concentrations >/=250 microM significantly reduced keratinocyte adherence as early as 3 h after exposure. Endothelial monolayer permeability increased substantially with concentrations of SM >250 microM. These observations support the hypothesis that the pathogenic events necessary for SM-induced vesication (i.e., capillary leak and loss of keratinocyte adherence) at higher vesicating doses of SM (>/=500 microM) may depend on NAD loss with PARP activation and subsequent ATP-dependent effects on microfilament architecture. Vesication developing as a result of exposure to lower concentrations of SM presumably occurs by mechanisms that do not depend on loss of cellular ATP (e.g., apoptosis and direct SM-mediated damage to integrins and the basement membrane).
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