Basic properties and molecular mechanisms of exogenous chemical carcinogens

Quantitative structure-activity relationship and ADME prediction studies on series of spirooxindoles derivatives for anti-cancer activity against colon cancer cell line HCT-116

Forty-one derivatives of spirooxindoles, active against HCT-116 colon cancer cells, underwent pharmacophore-based 3D-QSAR analysis to understand their correlation with anti-cancer activity. The study identified a seven-point pharmacophore model (ADHHRRR1) and QSAR models, offering insights for lead optimization and novel analogue design, thus advancing anti-cancer drug discovery. This research underscores the value of molecular modeling in elucidating structure-activity relationships and enhancing drug development efforts.

Tattoos as a risk factor for malignant lymphoma: a population-based case-control study

Background

The popularity of tattoos has increased dramatically over the last few decades. Tattoo ink often contains carcinogenic chemicals, e.g., primary aromatic amines, polycyclic aromatic hydrocarbons, and metals. The tattooing process invokes an immunologic response that causes translocation of tattoo ink from the injection site. Deposition of tattoo pigment in lymph nodes has been confirmed but the long-term health effects remain unexplored. We used Swedish National Authority Registers with full population coverage to investigate the association between tattoo exposure and overall malignant lymphoma as well as lymphoma subtypes.

Methods

We performed a case-control study where we identified all incident cases of malignant lymphoma diagnosed between 2007 and 2017 in individuals aged 20-60 years in the Swedish National Cancer Register. Three random age- and sex-matched controls per case were sampled from the Total Population Register using incidence density sampling. We assessed exposure through a questionnaire in 2021, and data on potential confounders were retrieved from registers. We used multivariable logistic regression to estimate the incidence rate ratio (IRR) of malignant lymphoma in tattooed individuals.

Findings

The study population consisted of 11,905 individuals, and the response rate was 54% among cases (n = 1398) and 47% among controls (n = 4193). The tattoo prevalence was 21% among cases and 18% among controls. Tattooed individuals had a higher adjusted risk of overall lymphoma (IRR = 1.21; 95% CI 0.99-1.48). The risk of lymphoma was highest in individuals with less than two years between their first tattoo and the index year (IRR = 1.81; 95% CI 1.03-3.20). The risk decreased with intermediate exposure duration (three to ten years) but increased again in individuals who received their first tattoo ≥11 years before the index year (IRR = 1.19; 95% CI 0.94-1.50). We found no evidence of increasing risk with a larger area of total tattooed body surface. The risk associated with tattoo exposure seemed to be highest for diffuse large B-cell lymphoma (IRR 1.30; 95% CI 0.99-1.71) and follicular lymphoma (IRR 1.29; 95% CI 0.92-1.82).

Interpretation

Our findings suggested that tattoo exposure was associated with an increased risk of malignant lymphoma. More epidemiologic research is urgently needed to establish causality.

Funding

The Swedish Research Council for Health, Working Life and Welfare.

Pathological significance of heme oxygenase-1 as a potential tumor promoter in heme-induced colorectal carcinogenesis

The significance of the heme-metabolizing enzyme heme oxygenase-1 (HMOX1) in the pathogenesis of colorectal cancer (CRC) has not been fully explored. HMOX1 cytoprotection is imperative to limit oxidative stress. However, its roles in preventing carcinogenesis in response to high levels of heme are not thoroughly understood. This study reviews various mechanisms associated with the paradoxical role of HMOX1, which is advantageous for tumor growth, refractoriness, and survival of cancer cells amid oxidative stress in heme-induced CRC. The alternate role of HMOX1 promotes cell proliferation and metastasis through immune modulation and angiogenesis. Inhibiting HMOX1 has been found to reverse tumor promotion. Thus, HMOX1 acts as a conditional tumor promoter in CRC pathogenesis.

The association between ambient air pollution exposure and connective tissue sarcoma risk: a nested case-control study using a nationwide population-based database

A nationwide population-based database was utilized in a nested case-control study to explore the association between ambient air pollution exposure and the likelihood of developing connective tissue sarcoma. The study examined 280 cases of connective tissue sarcoma diagnosed between 2000 and 2012. A random sample of 1120 control subjects was selected from a subpopulation of claim records without a connective tissue sarcoma diagnosis in a 1:4 ratio. The control subjects were selected based on similar characteristics as the connective tissue sarcoma patients, including gender, birth year, and the year of diagnosis of the case group with medical records. Risk factors for connective tissue sarcoma were collected for analysis. Our data on exposure to air pollutants was collected from Taiwan's Air Quality Monitoring Network, which has been gathering air quality data from a growing network of sampling stations (now 76) throughout the country since 1997. It was discovered that the risk of connective tissue sarcoma was significantly increased by the Charlson comorbidity index (CCI), elevated levels of specific air pollution indices (e.g., total hydrocarbons (THC), fine particulate matter (PM2.5), and O3_8 (the annual mean of the daily maximum 8-h average concentration of O3), the High Pollutant Standards Index (hPSI) (the percentage of days in a given year in Taiwan where the PSI exceeds 100), and an insurable monthly wage over US$1100. Further investigation is needed to explore the involvement of these air pollutants in the formation of connective tissue sarcoma.

Computational Mechanistic Investigations of Biocatalytic Nitrenoid C-H Functionalizations via Engineered Heme Proteins

Engineered heme proteins were developed to possess numerous excellent biocatalytic nitrenoid C-H functionalizations. Computational approaches such as density functional theory (DFT), hybrid quantum mechanics/molecular mechanics (QM/MM), and molecular dynamics (MD) calculations were employed to help understand some important mechanistic aspects of these heme nitrene transfer reactions. This review summarizes advances of computational reaction pathway results of these biocatalytic intramolecular and intermolecular C-H aminations/amidations, focusing on mechanistic origins of reactivity, regioselectivity, enantioselectivity, diastereoselectivity as well as effects of substrate substituent, axial ligand, metal center, and protein environment. Some important common and distinctive mechanistic features of these reactions were also described with brief outlook of future development.

Monitoring residues of pesticides in food in Brazil: A multiscale analysis of the main contaminants, dietary cancer risk estimative and mechanisms associated

Introduction

Pesticides pose a risk for cancer development and progression. People are continuously exposed to such substances by several routes, including daily intake of contaminated food and water, especially in countries that are highly pesticide consumers and have very permissive legislation about pesticide contamination as Brazil. This work investigated the relationship among pesticides, food contamination, and dietary cancer risk.

Methods

Analyzed two social reports from the Brazilian Government: the Program for Analysis of Residues of Pesticides in Food (PARA) and The National Program for Control of Waste and Contaminants (PNCRC).

Results and discussion

First, we characterized the main pesticide residues detected over the maximum limits allowed by legislation or those prohibited for use in food samples analyzed across the country. Based on this list, we estimated the dietary cancer risks for some of the selected pesticides. Finally, we searched for data about dietary cancer risks and carcinogenic mechanisms of each pesticide. We also provided a critical analysis concerning the pesticide scenario in Brazil, aiming to discuss the food contamination levels observed from a geographical, political, and public health perspective. Exposures to pesticides in Brazil violate a range of human rights when food and water for human consumption are contaminated.

Concentration of Polycyclic Aromatic Hydrocarbons (PAHs) in Human Serum and Adipose Tissues and Stimulatory Effect of Naphthalene in Adipogenesis in 3T3-L1 Cells

Polycyclic aromatic hydrocarbons (PAHs) are one of the most prevalent classes of environmental pollutants. Some evidence shows that PAHs could be involved in human obesity. However, little is known about the distribution patterns of PAHs in human adipose tissue (AT) and the role of PAHs on adipogenesis/lipogenesis. The aims of this pilot study were to determine concentrations of 16 PAHs defined as high-priority pollutants in the plasma and adipose tissue of French and Polish bariatric patients, as well as their correlation with body mass index (BMI), plasma and AT adipokines expression levels. We finally investigated the role of naphthalene on cell proliferation, viability, and differentiation in 3T3-L1 preadipocytes. The concentration of most PAHs was similar in the three types of AT and it was significantly higher in AT as compared to plasma, suggesting bioaccumulation. Polish patients had higher PAH levels in AT than French ones. Only the concentration of naphthalene in AT was positively correlated with the BMI and serum or adipose chemerin, adiponectin and resistin expression, in French but not in Polish patients, who had significantly higher BMIs. Moreover, naphthalene exposure increased the cell proliferation of 3T3-L1 preadipocytes and lipogenesis, and increased the expression of genes involved in adipogenesis after cell differentiation. Taken together, PAHs and more particularly naphthalene could be an obesogenic molecule and increase the risk of obesity.

Mutagenesis induced by protonation of single-stranded DNA is linked to glycolytic sugar metabolism

Mutagenesis can be thought of as random, in the sense that the occurrence of each mutational event cannot be predicted with precision in space or time. However, when sufficiently large numbers of mutations are analyzed, recurrent patterns of base changes called mutational signatures can be identified. To date, some 60 single base substitution or SBS signatures have been derived from analysis of cancer genomics data. We recently reported that the ubiquitous signature SBS5 matches the pattern of single nucleotide polymorphisms (SNPs) in humans and has analogs in many species. Using a temperature-sensitive single-stranded DNA (ssDNA) mutation reporter system, we also showed that a similar mutational pattern in yeast is dependent on error-prone translesion DNA synthesis (TLS) and glycolytic sugar metabolism. Here, we further investigated mechanisms that are responsible for this form of mutagenesis in yeast. We first confirmed that excess sugar metabolism leads to increased mutation rate, which was detectable by fluctuation assay. Since glycolysis is known to produce excess protons, we then investigated the effects of experimental manipulations on pH and mutagenesis. We hypothesized that yeast metabolizing 8% glucose would produce more excess protons than cells metabolizing 2% glucose. Consistent with this, cells metabolizing 8% glucose had lower intracellular and extracellular pH values. Similarly, deletion of vma3 (encoding a vacuolar H⁺-ATPase subunit) increased mutagenesis. We also found that treating cells with edelfosine (which renders membranes more permeable, including to protons) or culturing in low pH media increased mutagenesis. Analysis of the mutational pattern attributable to 20 µM edelfosine treatment revealed similarity to the SBS5-like TLS- and glycolysis-dependant mutational patterns previously observed in ssDNA. Altogether, our results agree with multiple biochemical studies showing that protonation of nitrogenous bases can alter base pairing so as to stabilize some mispairs, and shed new light on a common form of intrinsic mutagenesis.

Intrinsic base substitution patterns in diverse species reveal links to cancer and metabolism

Analyses of large-scale cancer sequencing data have revealed that mutagenic processes can create distinctive patterns of base substitutions, called mutational signatures. Interestingly, mutational patterns resembling some of these signatures can also be observed in normal cells. To determine whether similar patterns exist more generally, we analyzed large data sets of genetic variation, including mutations from 7 model species and single nucleotide polymorphisms in 42 species, totaling >1.9 billion variants. We found that base substitution patterns for most species closely match single base substitution (SBS) mutational signature 5 in the Catalog of Somatic Mutations in Cancer (COSMIC) database. SBS5 is ubiquitous in cancers and also present in normal human cells, suggesting that similar patterns of genetic variation across so many species are likely due to conserved biochemistry. We investigated the mechanistic origins of the SBS5-like mutational pattern in Saccharomyces cerevisiae, and show that translesion DNA synthesis and sugar metabolism are directly linked to this form of mutagenesis. We propose that conserved metabolic processes in cells are coupled to continuous generation of genetic variants, which can be acted upon by selection to drive the evolution of biological entities.

Analyses of mutational patterns induced by formaldehyde and acetaldehyde reveal similarity to a common mutational signature

Formaldehyde and acetaldehyde are reactive small molecules produced endogenously in cells as well as being environmental contaminants. Both of these small aldehydes are classified as human carcinogens, since they are known to damage DNA and exposure is linked to cancer incidence. However, the mutagenic properties of formaldehyde and acetaldehyde remain incompletely understood, at least in part because they are relatively weak mutagens. Here, we use a highly sensitive yeast genetic reporter system featuring controlled generation of long single-stranded DNA regions to show that both small aldehydes induced mutational patterns characterized by predominantly C/G → A/T, C/G → T/A, and T/A → C/G substitutions, each in similar proportions. We observed an excess of C/G → A/T transversions when compared to mock-treated controls. Many of these C/G → A/T transversions occurred at TC/GA motifs. Interestingly, the formaldehyde mutational pattern resembles single base substitution signature 40 from the Catalog of Somatic Mutations in Cancer. Single base substitution signature 40 is a mutational signature of unknown etiology. We also noted that acetaldehyde treatment caused an excess of deletion events longer than 4 bases while formaldehyde did not. This latter result could be another distinguishing feature between the mutational patterns of these simple aldehydes. These findings shed new light on the characteristics of 2 important, commonly occurring mutagens.

Transcriptome analysis of human cholangiocytes exposed to carcinogenic 1,2-dichloropropane in the presence of macrophages in vitro

1,2-Dichloropropane (1,2-DCP), a synthetic organic solvent, has been implicated in causality of cholangiocarcinoma (bile duct cancer). 1,2-DCP-induced occupational cholangiocarcinoma show a different carcinogenic process compared to common cholangiocarcinoma, but its mechanism remains elusive. We reported previously that exposure of MMNK-1 cholangiocytes co-cultured with THP-1 macrophages, but not monocultured MMNK-1 cholangiocytes, to 1,2-DCP induced activation-induced cytidine deaminase (AID) expression, DNA damage and ROS production. The aim of this study was to identify relevant biological processes or target genes expressed in response to 1,2-DCP, using an in vitro system where cholangiocytes are co-cultured with macrophages. The co-cultured cells were exposed to 1,2-DCP at 0, 0.1 or 0.4 mM for 24 h, and then the cell lysates were assessed by transcriptome analysis. 1,2-DCP upregulated the expression of base excision repair genes in MMNK-1 cholangiocytes in the co-cultures, whereas it upregulated the expression of cell cycle-related genes in THP-1 macrophages. Activation of the base excision repair pathway might result from the previously observed DNA damage in MMNK-1 cholangiocytes co-cultured with THP-1 macrophages, although involvement of other mechanisms such as DNA replication, cell death or other types of DNA repair was not disproved. Cross talk interactions between cholangiocytes and macrophages leading to DNA damage in the cholangiocytes should be explored.

Age influences on the molecular presentation of tumours

Cancer is often called a disease of aging. There are numerous ways in which cancer epidemiology and behaviour change with the age of the patient. The molecular bases for these relationships remain largely underexplored. To characterise them, we analyse age-associations in the nuclear and mitochondrial somatic mutational landscape of 20,033 tumours across 35 tumour-types. Age influences both the number of mutations in a tumour (0.077 mutations per megabase per year) and their evolutionary timing. Specific mutational signatures are associated with age, reflecting differences in exogenous and endogenous oncogenic processes such as a greater influence of tobacco use in the tumours of younger patients, but higher activity of DNA damage repair signatures in those of older patients. We find that known cancer driver genes such as CDKN2A and CREBBP are mutated in age-associated frequencies, and these alter the transcriptome and predict for clinical outcomes. These effects are most striking in brain cancers where alterations like SUFU loss and ATRX mutation are age-dependent prognostic biomarkers. Using three cancer datasets, we show that age shapes the somatic mutational landscape of cancer, with clinical implications.

Toxicity and removal of parabens from water: A critical review

Parabens are biocides used as preservatives in food, cosmetics and pharmaceuticals. They possess antibacterial and antifungal activity due to their ability to disrupt cell membrane and intracellular proteins, and cause changes in enzymatic activity of microbial cells. Water, one of our most valuable natural resource, has become a huge reservoir for parabens. Halogenated parabens from chlorination/ozonation of water contaminated with parabens have shown to be even more persistent in water than other types of parabens. Unfortunately, there is dearth of data on their (halogenated parabens) presence and fate in groundwater which serves as a major source of drinking water for a huge population in developing countries. An attempt to neglect the presence of parabens in water will expose man to it through ingestion of contaminated food and water. Although there are reviews on the occurrence, fate and behaviour of parabens in the environment, they largely omit toxicity and removal aspects. This review therefore, presents recent reports on the acute and chronic toxicity of parabens, their estrogenic agonistic and antagonistic activity and also their relationship with antimicrobial resistance. This article further X-rays several techniques that have been employed for the removal of parabens in water and their drawbacks including adsorption, biodegradation, membrane technology and advanced oxidation processes (AOPs). The heterogeneous photocatalytic process (one of the AOPs) appears to be more favoured for removal of parabens due to its ability to mineralize parabens in water. However, more work is needed to improve this ability of heterogeneous photocatalysts. Perspectives that will be relevant for future scientific studies and which will drive policy shift towards the presence of parabens in our drinking waters are also offered. It is hoped that this review will elicit some spontaneous actions from water professionals, scientists and policy makers alike that will provide more data, effective technologies, and adaptive policies that will address the growing threat of the presence of parabens in our environment with respect to human health.

The Critical Importance of Molecular Biomarkers and Imaging in the Study of Electrohypersensitivity. A Scientific Consensus International Report

Clinical research aiming at objectively identifying and characterizing diseases via clinical observations and biological and radiological findings is a critical initial research step when establishing objective diagnostic criteria and treatments. Failure to first define such diagnostic criteria may lead research on pathogenesis and etiology to serious confounding biases and erroneous medical interpretations. This is particularly the case for electrohypersensitivity (EHS) and more particularly for the so-called "provocation tests", which do not investigate the causal origin of EHS but rather the EHS-associated particular environmental intolerance state with hypersensitivity to man-made electromagnetic fields (EMF). However, because those tests depend on multiple EMF-associated physical and biological parameters and have been conducted in patients without having first defined EHS objectively and/or endpoints adequately, they cannot presently be considered to be valid pathogenesis research methodologies. Consequently, the negative results obtained by these tests do not preclude a role of EMF exposure as a symptomatic trigger in EHS patients. Moreover, there is no proof that EHS symptoms or EHS itself are caused by psychosomatic or nocebo effects. This international consensus report pleads for the acknowledgement of EHS as a distinct neuropathological disorder and for its inclusion in the WHO International Classification of Diseases.

Karanjin

Karanjin [IUPAC: 3-methoxy-2-phenylfuro-(2,3-h-chrome-4-ol)], a bioactive furanoflavonoid and a potent biomolecule, was first isolated from Pongamia pinnata (L.). The crude extracts from root, leaf and seed having active constituent karanjin is highly valued in both traditional and modern knowledge systems. This review highlights, critically assesses, and presents the probable biosynthetic pathways of karanjin and its isolation methodologies with a view to actualizing its full potential. Karanjin exhibits multiple health benefits and applications, with evident anti-diabetic, anti-cancer, anti-inflammatory, anti-hyperglycemic, antioxidant, anti-colitis, anti-ulcer, and anti-Alzheimer properties. Consequently, the physiochemical properties and biological effects of karanjin have been detailed and analyzed. The efficacy of karanjin has been attenuated by toxicological studies that have proven karanjin to be non-toxic at physiological conditions as substantiated by in vitro and in vivo studies. In addition, the multiple insect repellent/insecticidal properties of karanjin and its availability as an acaricide/bio-insecticide have been reviewed. This review article underscores and endorses the immense potential for novel drug leads in various medicinal and industrial applications, suggesting a deeper insight into its metabolic fate, bioavailability, and cellular effects that await further investigations.

Gamma-radiated immunosuppressed tumor xenograft mice can be a new ideal model in cancer research

Tumor xenograft models can create a high capacity to study human tumors and discover efficient therapeutic approaches. Here, we aimed to develop the gamma-radiated immunosuppressed (GIS) mice as a new kind of tumor xenograft model for biomedical studies. First, 144 mice were divided into the control and treated groups exposed by a medical Cobalt-60 apparatus in 3, 4, and 5 Gy based on the system outputs. Then, 144 BALB/c mice were divided into four groups; healthy, xenograft, radiation, and radiation + xenograft groups. The animals in the xenograft and radiation + xenograft groups have subcutaneously received 3 × 106 MCF-7 cells 24 h post-radiation. On 3, 7, 14, and 21 days after cell injection, the animals were sacrificed. Then, the blood samples and the spleen and tumor tissues were removed for the cellular and molecular analyses. The whole-body gamma radiation had a high immunosuppressive effect on the BALB/c mice from 1 to 21 days post-radiation. The macroscopic and histopathological observations have proved that the created clusters' tumor structure resulted in the xenograft breast tumor. There was a significant increase in tumor size after cell injection until the end of the study. Except for Treg, the spleen level of CD4, CD8, CD19, and Ly6G was significantly decreased in Xen + Rad compared to the Xen alone group on 3 and 7 days. Unlike IL-4 and IL-10, the spleen level of TGF-β, INF-γ, IL-12, and IL-17 was considerably decreased in the Xen + Rad than the Xen alone group on 3 and 7 days. The spleen expressions of the VEGF, Ki67, and Bax/Bcl-2 ratio were dramatically increased in the Xen + Rad group compared to the Xen alone on 3, 7, 14, and 21 days. Our results could confirm a new tumor xenograft model via an efficient immune-suppressive potential of the whole-body gamma radiation in mice.

Improvement of obesity-associated disorders by a small-molecule drug targeting mitochondria of adipose tissue macrophages

Pro-inflammatory activation of adipose tissue macrophages (ATMs) is causally linked to obesity and obesity-associated disorders. A number of studies have demonstrated the crucial role of mitochondrial metabolism in macrophage activation. However, there is a lack of pharmaceutical agents to target the mitochondrial metabolism of ATMs for the treatment of obesity-related diseases. Here, we characterize a near-infrared fluorophore (IR-61) that preferentially accumulates in the mitochondria of ATMs and has a therapeutic effect on diet-induced obesity as well as obesity-associated insulin resistance and fatty liver. IR-61 inhibits the classical activation of ATMs by increasing mitochondrial complex levels and oxidative phosphorylation via the ROS/Akt/Acly pathway. Taken together, our findings indicate that specific enhancement of ATMs oxidative phosphorylation improves chronic inflammation and obesity-related disorders. IR-61 might be an anti-inflammatory agent useful for the treatment of obesity-related diseases by targeting the mitochondria of ATMs.

Adipose tissue macrophages are central to controlling inflammation in the context of obesity. Here the authors present a new infrared dye (IR-61) that accumulates in the mitochondria of these cells resulting in anti-inflammatory effects that counter obesity-associated pathology in mice.

Al-thamili D, Almansour AI, Arumugam N, Mohammad F. A One-Pot Three-Component Synthesis and Investigation of the In Vitro Mechanistic Anticancer Activity of Highly Functionalized Spirooxindole-Pyrrolidine Heterocyclic Hybrids

With an aim to develop more effective and affordable anticancer agents possessing a unique mechanism of action, we designed and synthesized derivatives of spirooxindole-pyrrolidine heterocyclic hybrids in good yields through a one-pot three-component (3+2) cycloaddition strategy. The synthesized compounds were characterized thoroughly for the physicochemical properties by making use of FT-IR, NMR spectroscopy, and mass spectrometry. Further, these compounds have been evaluated for the influence of anticancer activity against HepG2 cells up to 200 µg/mL concentration. The highly active molecular scaffold was tested for the in-depth mechanistic studies, and it was found that the major pathway of cell death is apoptosis which occurs through the induction of reactive oxygen species followed by the involvement of caspases.

Occurrence and AhR activity of brominated parabens in the Kitakami River, North Japan

Parabens are used as preservatives in pharmaceuticals and personal care products (PPCPs). Parabens react with aqueous chlorine, which is used in disinfection processes, leading to the formation of halogenated parabens. In the presence of Br^-, parabens and HOBr (formed via oxidation of Br^-) can react to form brominated parabens. Brominated parabens may result in pollution of river water through effluent discharge from sewage treatment plants. The present study involved measuring brominated paraben concentrations in the Kitakami River, northern Japan, which flows through urban and agricultural areas. Aryl hydrocarbon receptor (AhR) agonist activity was also assessed using a yeast (YCM3) reporter gene and HepG2 ethoxyresorufin O-deethylase (EROD) assays. Dibrominated methylparaben (Br2MP), ethylparaben (Br2EP), propylparaben (Br2PP), butylparaben (Br2BP), and benzylparaben (Br2BnP), and monobrominated benzylparaben (Br1BnP) were detected in 25-100% of river samples during the sampling period from 2017 to 2018 at median concentrations of 8.1-28 ng/L; the highest concentrations were measured during the low flow season (November) in urban areas (P < 0.01). In the yeast assay, 12 compounds exhibited AhR activity (activity relative to β-naphthoflavone; 4.4 × 10^-4-7.1 × 10^-1). All monobrominated parabens exhibited higher activity than their parent parabens, however, further bromination reduced or eliminated their activity. In the EROD assay, five compounds caused significant induction of CYP1A-dependent activity at 100 μM (P < 0.05). Monobrominated i-butylparaben (Br1iBP) and s-butylparaben (Br1sBP), Br1BnP, and Br2BP exhibited activity in both yeast and EROD assays. We found novel aspects of brominated parabens originating from PPCPs.

Sleeve gastrectomy ameliorates endothelial function and prevents lung cancer by normalizing endothelin-1 axis in obese and diabetic rats

BACKGROUND

Previous evidence has implied that obesity is an independent risk factor for developing cancer. Being closely related to obesity, type 2 diabetes mellitus provides a suitable environment for the formation and metastasis of tumors through multiple pathways. Although bariatric surgeries are effective in preventing and lowering the risk of various types of cancer, the underlying mechanisms of this effect are not clearly elucidated.

AIM

To uncover the role and effect of sleeve gastrectomy (SG) in preventing lung cancer in obese and diabetic rats.

METHODS

SG was performed on obese and diabetic Wistar rats, and the postoperative transcriptional and translational alterations of the endothelin-1 (ET-1) axis in the lungs were compared to sham-operated obese and diabetic rats and age-matched healthy controls to assess the improvements in endothelial function and risk of developing lung cancer at the postoperative 4^th, 8^th, and 12^th weeks. The risk was also evaluated using nuclear phosphorylation of H2A histone family member X as a marker of DNA damage (double-strand break).

RESULTS

Compared to obese and diabetic sham-operated rats, SG brought a significant reduction to body weight, food intake, and fasting blood glucose while improving oral glucose tolerance and insulin sensitivity. In addition, ameliorated levels of gene and protein expression in the ET-1 axis as well as reduced DNA damage indicated improved endothelial function and a lower risk of developing lung cancer after the surgery.

CONCLUSION

Apart from eliminating metabolic disorders, SG improves endothelial function and plays a protective role in preventing lung cancer via normalized ET-1 axis and reduced DNA damage.

Application of transcriptomic and microRNA profiling in the evaluation of potential liver carcinogens

Hepatocarcinogens are agents that increase the incidence of liver cancer in exposed animals or humans. It is now established that carcinogenic exposures have a widespread impact on the transcriptome, inducing both adaptive and adverse changes in the activities of genes and pathways. Chemical hepatocarcinogens have also been shown to affect expression of microRNA (miRNA), the evolutionarily conserved noncoding RNA that regulates gene expression posttranscriptionally. Considerable effort has been invested into examining the involvement of mRNA in chemical hepatocarcinogenesis and their potential usage for the classification and prediction of new chemical entities. For miRNA, there has been an increasing number of studies reported over the past decade, although not to the same degree as for transcriptomic studies. Current data suggest that it is unlikely that any gene or miRNA signature associated with short-term carcinogen exposure can replace the rodent bioassay. In this review, we discuss the application of transcriptomic and miRNA profiles to increase mechanistic understanding of chemical carcinogens and to aid in their classification.

Organochlorine pesticides induce inflammation, ROS production, and DNA damage in human epithelial ovary cells: An in vitro study

Although the etiology of ovarian cancer is not clear, certain factors are implicated in this disease, such as ovulation, gonadotropic and steroid hormones, growth factors, cytokines, environmental agents, etc. Epidemiological studies have proven environmental exposure to pesticides with an increased risk of Epithelial Ovarian Cancer (EOC); however, the molecular mechanism underlying the carcinogenic effects of pesticides in human ovary remains poorly understood. The present study aimed to study the pro-inflammatory response of organochlorine pesticides (OCPs) namely β-hexachlorocyclohexane (β-HCH), dichlorodiphenyldichloroethylene (DDE) and Dieldrin following exposure to human ovary surface epithelial cells (HOSE) for risk prediction of epithelial ovarian cancer. We found high level of Reactive oxygen species (ROS) production and DNA damage along with up-regulation of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, nuclear factor kappa B (NF-kB) and cyclooxygenase (COX)-2 expression in OCPs treated HOSE cells compared to control (DMSO). The result of the present study suggests that β-HCH, DDE, and Dieldrin exposure induce ROS and pro-inflammatory response as well as DNA damage in HOSE cells. These various results show that OCPs may account for the neoplastic transformation of HOSE cells in the ovary.

Electrohypersensitivity as a Newly Identified and Characterized Neurologic Pathological Disorder: How to Diagnose, Treat, and Prevent It

Since 2009, we built up a database which presently includes more than 2000 electrohypersensitivity (EHS) and/or multiple chemical sensitivity (MCS) self-reported cases. This database shows that EHS is associated in 30% of the cases with MCS, and that MCS precedes the occurrence of EHS in 37% of these EHS/MCS-associated cases. EHS and MCS can be characterized clinically by a similar symptomatic picture, and biologically by low-grade inflammation and an autoimmune response involving autoantibodies against O-myelin. Moreover, 80% of the patients with EHS present with one, two, or three detectable oxidative stress biomarkers in their peripheral blood, meaning that overall these patients present with a true objective somatic disorder. Moreover, by using ultrasonic cerebral tomosphygmography and transcranial Doppler ultrasonography, we showed that cases have a defect in the middle cerebral artery hemodynamics, and we localized a tissue pulsometric index deficiency in the capsulo-thalamic area of the temporal lobes, suggesting the involvement of the limbic system and the thalamus. Altogether, these data strongly suggest that EHS is a neurologic pathological disorder which can be diagnosed, treated, and prevented. Because EHS is becoming a new insidious worldwide plague involving millions of people, we ask the World Health Organization (WHO) to include EHS as a neurologic disorder in the international classification of diseases.

Ion Channel Regulation by Sex Steroid Hormones and Vitamin D in Cancer: A Potential Opportunity for Cancer Diagnosis and Therapy

Many ion channels are involved in tumor development, promoting cancer cell proliferation, migration, invasion, and survival. Accordingly, some of them have been suggested as tumor markers and novel targets for cancer therapy. Some sex steroid hormones (SSH), including estrogens and androgens, favor cancer progression. Meanwhile, other steroid hormones like vitamin D may have anticancer properties. SSH and vitamin D modulate the expression of a number of ion channels in cancer cells from hormone-sensitive tissues, including breast, ovary, prostate, and cervix. Moreover, rapid effects of SSH may be mediated by their direct action on membrane ion channels. Here, we reviewed the SSH and vitamin D regulation of ion channels involved in cancer, and analyzed the potential molecular pathways implicated. In addition, we described the potential clinical use of ion channels in cancer diagnosis and therapy, taking advantage of their regulation by SSH and vitamin D. Since SSH are considered risk factors for different types of cancer, and ion channels play important roles in tumor progression, the regulation of ion channels by SSH and vitamin D may represent a potential opportunity for early cancer diagnosis and therapeutic approaches in SSH and vitamin D sensitive tumors.

Circulating free methylglyoxal as a metabolic tumor biomarker in a rat colon adenocarcinoma model

Since the 1956 hypothesis of Otto Warburg, aerobic glycolysis has been recognized as a metabolic hallmark of cancer. Because methylglyoxal (MG) is a naturally occurring waste metabolite of glycolysis, we measured blood levels of this molecule in colon cancer-bearing rats. To compare the blood levels of free MG in cancerous and healthy animals,the present study used a dedicated tumor graft model consisting of the subcutaneous administration in syngenic BD-IX rats of a tumorigenic cell clone (PROb) and another non-tumorigenic clone (REGb) derived from the same tumor. Rats grafted with the PROb growing tumor cell clone exhibited a statistically significant increase in free MG blood levels (P=0.003), whereas rats transplanted with the REGb non-growing tumor cell clone exhibited normal MG values. The present study (first of three parts) suggests that cancer cells can produce and release free MG at higher levels than normal cells, making MG a putative novel metabolic biomarker of cancer.

The Effect of Visceral Abdominal Fat Volume on Oxidative Stress and Proinflammatory Cytokines in Subjects with Normal Weight, Overweight and Obesity

PURPOSE

The increase of visceral abdominal fat (VAF) and oxidative stress (OS) are independent predictors for cardiovascular risk. This study aimed to determine the association of VAF with proinflammatory cytokines, oxidants, antioxidants, and oxidative damage to DNA in subjects with normal weight, overweight, and obesity.

PATIENTS AND METHODS

A cross-sectional study that included 21 men and 71 women who attended for a medical check-up was conducted. Dual-energy X-ray absorptiometry (DXA) was used to measure the VAF volume. ELISA and colorimetric techniques were used for chemical analysis.

RESULTS

Low activity of superoxide dismutase (SOD) was found in overweight and obese subjects compared to the normal weight group (p=0.005). In contrast, the activity of glutathione peroxidase (GPx) was higher in the overweight and obesity groups compared to the normal weight subjects (p=0.017). The total antioxidant capacity (TAC) was also increased in the overweight group compared to the normal weight group (p=0.04). According to the volume of VAF, the levels of tumor necrosis factor alfa and interleukin 6 showed no differences between subjects with normal and high VAF. Subjects with high VAF show higher levels of 8-isoprostans compared to normal VAF group (p=0.039). Less concentration of 8-oxoguanine-DNA-N-glycosylase-1 (hOGG1) was found in the high VAF group (p=0.032) compared to the normal VAF subjects. VAF was positively correlated with lipoperoxides (LPO) (r=0.27, p<0.05) and 8-isoprostanes (r=0.25, p<0.05). We also found correlations between oxidative stress markers and anthropometric ratios for intra-abdominal fat. The waist-hip ratio was positively correlated with LPO (r=0.30, p<0.05) and TAC (r=0.24, p<0.05).

CONCLUSION

These findings suggest that the predominantly oxidative damage associated with VAF in overweight or obesity is lipoperoxidation and oxidative DNA damage. Alterations in endogenous antioxidant defenses may not be linked to the amount of VAF.

Obesity, DNA Damage, and Development of Obesity-Related Diseases

Obesity has been recognized to increase the risk of such diseases as cardiovascular diseases, diabetes, and cancer. It indicates that obesity can impact genome stability. Oxidative stress and inflammation, commonly occurring in obesity, can induce DNA damage and inhibit DNA repair mechanisms. Accumulation of DNA damage can lead to an enhanced mutation rate and can alter gene expression resulting in disturbances in cell metabolism. Obesity-associated DNA damage can promote cancer growth by favoring cancer cell proliferation and migration, and resistance to apoptosis. Estimation of the DNA damage and/or disturbances in DNA repair could be potentially useful in the risk assessment and prevention of obesity-associated metabolic disorders as well as cancers. DNA damage in people with obesity appears to be reversible and both weight loss and improvement of dietary habits and diet composition can affect genome stability.

Priming stem cells with protein kinase C activator enhances early stem cell-chondrocyte interaction by increasing adhesion molecules

BACKGROUND

Osteoarthritis (OA) can be defined as degradation of articular cartilage of the joint, and is the most common degenerative disease. To regenerate the damaged cartilage, different experimental approaches including stem cell therapy have been tried. One of the major limitations of stem cell therapy is the poor post-transplantation survival of the stem cells. Anoikis, where insufficient matrix support and adhesion to extracellular matrix causes apoptotic cell death, is one of the main causes of the low post-transplantation survival rate of stem cells. Therefore, enhancing the initial interaction of the transplanted stem cells with chondrocytes could improve the therapeutic efficacy of stem cell therapy for OA. Previously, protein kinase C activator phorbol 12-myristate 13-acetate (PMA)-induced increase of mesenchymal stem cell adhesion via activation of focal adhesion kinase (FAK) has been reported. In the present study, we examine the effect PMA on the adipose-derived stem cells (ADSCs) adhesion and spreading to culture substrates, and further on the initial interaction between ADSC and chondrocytes.

RESULTS

PMA treatment increased the initial adhesion of ADSC to culture substrate and cellular spreading with increased expression of adhesion molecules, such as FAK, vinculin, talin, and paxillin, at both RNA and protein level. Priming of ADSC with PMA increased the number of ADSCs attached to confluent layer of cultured chondrocytes compared to that of untreated ADSCs at early time point (4 h after seeding).

CONCLUSION

Taken together, the results of this study suggest that priming ADSCs with PMA can increase the initial interaction with chondrocytes, and this proof of concept can be used to develop a non-invasive therapeutic approach for treating OA. It may also accelerate the regeneration process so that it can relieve the accompanied pain faster in OA patients. Further in vivo studies examining the therapeutic effect of PMA pretreatment of ADSCs for articular cartilage damage are required.

Increased exposure to pesticides and colon cancer: Early evidence in Brazil

Environmental factors may increase colon cancer (CC) risk. It has been suggested that pesticides could play a significant role in the etiology of this malignancy. As agriculture is one of the mainstays of the Brazilian economy, this country has become the largest pesticides consumer worldwide. The CC burden is also increasing in Brazil. Herein, we examined data from the Brazilian Federal Government to determine whether CC mortality and pesticide consumption may be associated. Database of the Ministry of Health provided CC mortality data in Brazil, while pesticide usage was accessed at the website of Brazilian Institute of Environment and Renewable Natural Resources. The CC mortality in the Brazilian states was calculated as standard mortality rates (SMR). All Bayesian analysis was performed using a Markov chain Monte Carlo method in WinBUGS software. We observed that CC mortality has exhibited a steady increase for more than a decade, which correlated with the amount of sold pesticides in the country. Both observations are concentrated in the Southern and the Southeast regions of Brazil. Although ecological studies like ours have methodological limitations, the current dataset suggests the possibility that pesticide exposure may be a risk factor for CC. It warrants further investigation.

Preventive Potential of Resveratrol in Carcinogen-Induced Rat Thyroid Tumorigenesis

Thyroid cancer (TC) is the most common endocrine malignancy without reliable preventive agent. Resveratrol possesses in vitro anti-TC activities; while its effect(s) on thyroid tumorigenesis remains unknown. This study aims to address this issue using DEN/MNU/DHPN-induced rat carcinogenesis model. 50 male Sprague-Dawley rats were separated into four groups as Group-1 (5 rats); normally fed; Group-2 (15 rats); DEN/MNU/DHPN treatment only; Group-3 (15 rats) and -4 (15 rats); DEN/MNU/DHPN treatment; followed by resveratrol intragastric (IG) injection and intraperitoneal (IP) injection; respectively; in two-day intervals for 30 weeks. The results revealed that the average resveratrol concentration in thyroid tissues was 1.278 ± 0.419 nmol/g in IG group and 1.752 ± 0.398 nmol/g in IP group. The final body weights of Group-3 and Group-4 were lighter than that (p > 0.05) of Group-1; but heavier than Group-2 (p < 0.05). TC-related lesions (hyperplasia and adenomas) were found in 53.3% of Group-2; 33.3% Group-3 and 26.7% Group-4. Lower serum carcino-embryonic antigen (CEA) and thyroglobulin (Tg) levels; down-regulated expression of IL-6 and cyclooxygenase-2 (COX-2); reduction of NF-κB/p65 nuclear translocation; and elevated IkBα expression were found in the thyroid tissues of Group-3 and Group-4 in comparison with that of Group-2. These results demonstrate that IG and IP administered resveratrol efficiently reduces the frequency and severity of DEN/MNU/DHPN-caused TC-related lesions and would be of values in thyroid tumor prevention.

Molecular Genetic Characterization of Mutagenesis Using a Highly Sensitive Single-Stranded DNA Reporter System in Budding Yeast

Mutations are permanent alterations to the coding content of DNA. They are starting material for the Darwinian evolution of species by natural selection, which has yielded an amazing diversity of life on Earth. Mutations can also be the fundamental basis of serious human maladies, most notably cancers. In this chapter, I describe a highly sensitive reporter system for the molecular genetic analysis of mutagenesis, featuring controlled generation of long stretches of single-stranded DNA in budding yeast cells. This system is ~100- to ~1000-fold more susceptible to mutation than conventional double-stranded DNA reporters, and is well suited for generating large mutational datasets to investigate the properties of mutagens.

A Perspective Discussion on Rising Pesticide Levels and Colon Cancer Burden in Brazil

Agriculture is a mainstay of many developing countries’ economy, such as Brazil. According to the Food and Agriculture Organization of the United Nations, Brazil is the major global consumer of pesticides. Irrespective of the fact that the International Agency for Research on Cancer suggests that pesticides promote human cancer risk, a prospective study reports that colorectal cancer (CRC) burden will increase in developing countries by approximately 60% in the coming decades. Here, we review the literature and public data from the Brazilian Federal Government to explore why pesticides levels and new cases of colon cancer (CC) are rising rapidly in the country. CC incidence is the second most common malignancy in men and women in the South and the Southeast of Brazil. However, while these regions have almost doubled their pesticide levels and CC mortality in 14 years, the amount of sold pesticides increased 5.2-fold with a corresponding 6.2-fold increase in CC mortality in Northern and Northeastern states. Interestingly, mortality from endocrine, nutritional, and metabolic diseases are rapidly increasing, in close resemblance with the pesticide detection levels in food. Taken together, we discuss the possibility that pesticides might alter the risk of CC.

DNA Damage Tolerance by Eukaryotic DNA Polymerase and Primase PrimPol

PrimPol is a human deoxyribonucleic acid (DNA) polymerase that also possesses primase activity and is involved in DNA damage tolerance, the prevention of genome instability and mitochondrial DNA maintenance. In this review, we focus on recent advances in biochemical and crystallographic studies of PrimPol, as well as in identification of new protein-protein interaction partners. Furthermore, we discuss the possible functions of PrimPol in both the nucleus and the mitochondria.

Effects of dietary beef, pork, chicken and salmon on intestinal carcinogenesis in A/J Min/+ mice

The International Agency for Research on Cancer has classified red meat as “probably carcinogenic to humans” (Group 2A). In mechanistic studies exploring the link between intake of red meat and CRC, heme iron, the pigment of red meat, is proposed to play a central role as a catalyzer of luminal lipid peroxidation and cytotoxicity. In the present work, the novel A/J Min/+ mouse was used to investigate the effects of dietary beef, pork, chicken, or salmon (40% muscle food (dry weight) and 60% powder diet) on Apc-driven intestinal carcinogenesis, from week 3–13 of age. Muscle food diets did not differentially affect carcinogenesis in the colon (flat ACF and tumors). In the small intestine, salmon intake resulted in a lower tumor size and load than did meat from terrestrial animals (beef, pork or chicken), while no differences were observed between the effects of white meat (chicken) and red meat (pork and beef). Additional results indicated that intestinal carcinogenesis was not related to dietary n-6 polyunsaturated fatty acids, intestinal formation of lipid peroxidation products (thiobarbituric acid reactive substances, TBARS), or cytotoxic effects of fecal water on Apc^-/+ cells. Notably, the amount of heme reaching the colon appeared to be relatively low in this study. The greatest tumor load was induced by the reference diet RM1, underlining the importance of the basic diets in experimental CRC. The present study in A/J Min/+ mice does not support the hypothesis of a role of red meat in intestinal carcinogenesis.

Dietary lipids differentially modulate the initiation of experimental breast carcinogenesis through their influence on hepatic xenobiotic metabolism and DNA damage in the mammary gland

Breast cancer is the most common malignancy among women worldwide. In addition to reproductive factors, environmental factors such as nutrition and xenobiotic exposure have a role in the etiology of this malignancy. A stimulating and a potentially protective effect on experimental breast cancer has been previously described for high corn oil and high extra-virgin olive oil diets, respectively. This work investigates the effect of these lipids on the metabolism of 7,12-dimethylbenz(a)anthracene (DMBA), a polycyclic aromatic hydrocarbon that can initiate carcinogenesis and its consequences in an experimental rat breast cancer model. The PUFA n-6-enriched diet increased expression of Phase I enzymes prior to DMBA administration and raised the activity of CYP1s in the hours immediately after induction, while reducing the activity of Phase II enzymes, mainly NQO1. The levels of reactive metabolites measured in plasma by GC-MS and DMBA-DNA adducts in the mammary gland of the animals fed the high corn oil diet were also higher than in the other groups. On the other hand, the high extra-virgin olive oil diet and the control low-fat diet exhibited better coordinated Phase I and Phase II activity, with a lower production of reactive metabolites and less DNA damage in the mammary gland. The concordance between these effects and the different efficacy of the carcinogenesis process due to the dietary treatment suggest that lipids may differently modify mammary gland susceptibility or resistance to cancer initiation over the exposure to environmental carcinogens.

SUMMARY

Dietary lipids influence the initiation of DMBA-induced mammary cancer through the modulation of liver xenobiotic metabolism, formation of reactive metabolites and subsequent DNA damage in the target tissue.

Procarcinogens - Determination and Evaluation by Yeast-Based Biosensor Transformed with Plasmids Incorporating RAD54 Reporter Construct and Cytochrome P450 Genes

In Vietnam, a great number of toxic substances, including carcinogens and procarcinogens, from industrial and agricultural activities, food production, and healthcare services are daily released into the environment. In the present study, we report the development of novel yeast-based biosensor systems to determine both genotoxic carcinogens and procarcinogens by cotransformation with two plasmids. One plasmid is carrying human CPR and CYP (CYP3A4, CYP2B6, or CYP2D6) genes, while the other contains the RAD54-GFP reporter construct. The three resulting coexpression systems bearing both CPR-CYP and RAD54-GFP expression cassettes were designated as CYP3A4/CYP2B6/CYP2D6 + RAD54 systems, respectively and used to detect and evaluate the genotoxic potential of carcinogens and procarcinogens by selective activation and induction of both CPR-CYP and RAD54-GFP expression cassettes in response to DNA damage. Procarcinogens were shown to be predominantly, moderately or not bioactivated by one of the CYP enzymes and thus selectively detected by the specific coexpression system. Aflatoxin B₁ and benzo(a)pyrene were predominantly detected by the CYP3A4 + RAD54 system, while N-nitrosodimethylamine only moderately activated the CYP2B6 + RAD54 reporter system and none of them was identified by the CYP2D6 + RAD54 system. In contrast, the genotoxic carcinogen, methyl methanesulfonate, was detected by all systems.

Our yeast-reporter system can be performed in 384-well microplates to provide efficient genotoxicity testing to identify various carcinogenic compounds and reduce chemical consumption to about 53% as compared with existing 96-well genotoxicity bioassays. In association with a liquid handling robot, this platform enables rapid, cost-effective, and high-throughput screening of numerous analytes in a fully automated and continuous manner without the need for user interaction.

Chemomodulatory Potential of Flaxseed Oil Against DMBA/Croton Oil-Induced Skin Carcinogenesis in Mice

The present study was conducted to evaluate the potential of flaxseed oil to prevent chemically induced skin cancer in mice. Cancer was induced on 2-stage skin carcinogenesis model by single topical application of 7,12 dimethylbenz [a]anthracene (DMBA), as, initiator, and two weeks later it was promoted by croton oil treatment thrice a week on the dorsal surface of mice for 16 weeks. Flaxseed oil (FSO; 100µL/animal/d) was orally administered 1 week before and 1 week after DMBA application (Peri-initiation stage). The animals of the FSO-administered group showed a significant reduction in tumor incidence (76.67%), cumulative number of tumors (37), tumor yield (3.7), and tumor burden (4.81) when compared with the carcinogen-treated control animals. Biochemical parameters in skin and liver tissue such as LPO and phase I enzymes were significantly (P < .01) reduced in the FSO-treated experimental group, whereas the phase II enzymes (GST, DT-diaphorase) and antioxidant parameters (GSH, GPx, SOD, catalase, and vitamin C) exhibited a significant (P < .01) elevation when compared with the animals of the carcinogen-treated control group. Histopathological alterations in the carcinogen-treated control animals were also observed in the form of epidermal hyperplasia, keratinized pearl formation, and acanthosis in skin and tumors, whereas these were found to be reduced after FSO administration. The results of the present study demonstrate that the oral administration of FSO has the potential to modulate the levels of LPO, antioxidants, and detoxification enzymes in the DMBA-croton oil-induced skin carcinogenesis in mice.

Replicative random mutations as an unproven cause of cancer: A technical comment

A careful molecular biology, epidemiological and mathematical modelling reanalysis of the recently published study titled 'Cancer etiology. Variation in cancer risk among tissues can be explained by the number of stem cell divisions' by Cristian Tomasetti and Bert Vogelstein, which was published on January 2, 2015 in the distinguished journal Science, led to the conclusion that, contrary to the authors' claim, many cancer types are not caused by replicative random mutations. Rather than the authors' two arbitrarily individualized groups of cancer, a three-group model is herein proposed in the framework of this technical comment, considerably reducing the fraction of cancer cases hypothetically attributable to random mutations.

Mammalian models of chemically induced primary malignancies exploitable for imaging-based preclinical theragnostic research

Compared with transplanted tumor models or genetically engineered cancer models, chemically induced primary malignancies in experimental animals can mimic the clinical cancer progress from the early stage on. Cancer caused by chemical carcinogens generally develops through three phases namely initiation, promotion and progression. Based on different mechanisms, chemical carcinogens can be divided into genotoxic and non-genotoxic ones, or complete and incomplete ones, usually with an organ-specific property. Chemical carcinogens can be classified upon their origins such as environmental pollutants, cooked meat derived carcinogens, N-nitroso compounds, food additives, antineoplastic agents, naturally occurring substances and synthetic carcinogens, etc. Carcinogen-induced models of primary cancers can be used to evaluate the diagnostic/therapeutic effects of candidate drugs, investigate the biological influential factors, explore preventive measures for carcinogenicity, and better understand molecular mechanisms involved in tumor initiation, promotion and progression. Among commonly adopted cancer models, chemically induced primary malignancies in mammals have several advantages including the easy procedures, fruitful tumor generation and high analogy to clinical human primary cancers. However, in addition to the time-consuming process, the major drawback of chemical carcinogenesis for translational research is the difficulty in noninvasive tumor burden assessment in small animals. Like human cancers, tumors occur unpredictably also among animals in terms of timing, location and the number of lesions. Thanks to the availability of magnetic resonance imaging (MRI) with various advantages such as ionizing-free scanning, superb soft tissue contrast, multi-parametric information, and utility of diverse contrast agents, now a workable solution to this bottleneck problem is to apply MRI for noninvasive detection, diagnosis and therapeutic monitoring on those otherwise uncontrollable animal models with primary cancers. Moreover, it is foreseeable that the combined use of chemically induced primary cancer models and molecular imaging techniques may help to develop new anticancer diagnostics and therapeutics.

Catalytic and Biocatalytic Iron Porphyrin Carbene Formation: Effects of Binding Mode, Carbene Substituent, Porphyrin Substituent, and Protein Axial Ligand

Iron porphyrin carbenes (IPCs) are important intermediates in various chemical reactions catalyzed by iron porphyrins and engineered heme proteins, as well as in the metabolism of various xenobiotics by cytochrome P450. However, there are no prior theoretical reports to help understand their formation mechanisms and identify key information governing the binding mode, formation feasibility, and stability/reactivity. A systematic quantum chemical study was performed to investigate the effects of carbene substituent, porphyrin substituent, and axial ligand on IPC formation pathways. Results not only are consistent with available experimental data but also provide a number of unprecedented insights into electronic, steric, and H-bonding effects of various structural factors on IPC formation mechanisms. These results shall facilitate research on IPC and related systems for sustainable chemical catalysis and biocatalysis.

Selected Inflammatory and Metabolic Markers in Psoriatic Patients Treated with Goeckerman Therapy

Psoriasis is associated with metabolic activity of adipose tissue which produces pro- and anti-inflammatory adipokines. Goeckerman therapy (GT) represents an effective treatment of psoriasis. This study evaluated variation of selected inflammatory and metabolic markers during GT and the relationships between the markers, severity of the disease (PASI score), body mass, and the basic characteristics of the therapy. The study was conducted on a group of patients (n = 32) and on a control group (n = 24). Before GT, we found significantly elevated levels of proinflammatory CRP (p < 0.001) and leptin (p < 0.05) in psoriatic patients (compared to the controls). The therapy significantly decreased the levels of CRP and adiponectin. We found positive correlations between CRP and total duration of GT (p < 0.05) and CRP and the time of UV exposure (p < 0.01) and negative correlations between adiponectin and the total duration of GT (p < 0.05) and adiponectin and the application of CCT ointment (p < 0.001). From our results, we can conclude that GT causes partial reduction of both proinflammatory and anti-inflammatory markers. However, the levels of proinflammatory CRP and leptin remained significantly higher in the patients than in the control group.

Characterization of Somatic Mutations in Air Pollution-Related Lung Cancer

Air pollution has been classified as Group 1 carcinogenic to humans, but the underlying tumorigenesis remains unclear. In Xuanwei City of Yunnan Province, the lung cancer incidence is among the highest in China attributed to severe air pollution generated by combustion of smoky coal, providing a unique opportunity to dissect lung carcinogenesis of air pollution. Here we analyzed the somatic mutations of 164 non-small cell lung cancers (NSCLCs) from Xuanwei and control regions (CR) where smoky coal was not used. Whole genome sequencing revealed a mean of 289 somatic exonic mutations per tumor and the frequent C:G → A:T nucleotide substitutions in Xuanwei NSCLCs. Exome sequencing of 2010 genes showed that Xuanwei and CR NSCLCs had a mean of 68 and 22 mutated genes per tumor, respectively (p < 0.0001). We found 167 genes (including TP53, RYR2, KRAS, CACNA1E) which had significantly higher mutation frequencies in Xuanwei than CR patients, and mutations in most genes in Xuanwei NSCLCs differed from those in CR cases. The mutation rates of 70 genes (e.g., RYR2, MYH3, GPR144, CACNA1E) were associated with patients' lifetime benzo(a)pyrene exposure. This study uncovers the mutation spectrum of air pollution-related lung cancers, and provides evidence for pollution exposure-genomic mutation relationship at a large scale.

Endocrine disruptors and female cancer: Informing the patients (Review)

Pollutants altering the endocrine system, known as endocrine disruptors (ED), may modify the risk of female cancers. The carcinogenic effect of ED on humans has been confirmed by experimental studies for various substances including pesticides, DDT, dioxins, phthalates, bisphenol A, diethylstilbestrol, as well as heavy metals, but it is difficult to quantify precisely for several reasons hereby reviewed. Carcinogenesis is a complex and multifactorial mechanism that manifests itself over a long period of time, making difficult the detection of the specific contribution of the pollutants, whose absorbed dose is often unknown. The combined effect of various substances leads to complex interactions whose outcome is difficult to predict. These substances may accumulate and carry out their harmful effect on critical periods of life, probably also at doses considered harmless to an adult. ED can also have epigenetic adverse effects on the health of future generations. In conclusion, the carcinogenic effects of endocrine disruptors on female cancer types is plausible although additional studies are needed to clarify their mechanisms and entities. In the last part of the review we suggest ways to reduce ED exposure as it is mandatory to implement necessary measures to limit exposure, particularly during those periods of life most vulnerable to the impact of oncogenic environmental causes, such as the embryonic period and puberty.