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Radiation Hormesis in Cancer
Published in T. D. Luckey, Radiation Hormesis, 2020
In a rare challenge experiment, intratracheal instillation of benzopyrene into rats which had chronically inhaled low levels of 239PO2 gave clear evidence that the two carcinogens were synergistic.614 Inhalation of the PuO2 alone rarely caused fatal cancers; the combination of PuO2 plus bensopyrene was lethal.
The Head and Neck
Published in E. George Elias, CRC Handbook of Surgical Oncology, 2020
Carcinoma of the nasopharynx has a predominance in the Chinese. Kwangtung Providence, including Hong Kong, had a high incidence. However, this is noted in the native Chinese, and is extremely rare in the white population living in the same area. Cooking fumes and smoke may also increase the incidence combined with the racial potential. Such fumes contain benzopyrene and other aromatic hydrocarbons. Another factor could be hereditary, as there is a higher frequency of developing this disease among relatives of patients with squamous cell carcinoma of the nasopharynx. A viral etiology has been proposed as some studies have suggested a relationship between Epstein-Barr virus and nasopharyngeal cancer.
Neoplasia
Published in C. Simon Herrington, Muir's Textbook of Pathology, 2020
It is now generally acknowledged that cigarette smoking is responsible for at least a quarter of cancer deaths, especially from cancers of the lung, larynx, oral cavity, and to a lesser extent breast, colorectum, blood, bladder, liver, pancreas and stomach. Most of the effects are due to direct contact with carcinogens in smoke, but these are also absorbed into the blood, circulated and excreted through the kidneys. Many carcinogens are present in smoke, including benzopyrene, other polycyclic hydrocarbons, and dimethylnitrosamine. There is a direct relationship between the number of cigarettes smoked and the risk of lung cancer and, although stopping smoking reduces this risk, its effects are not completely reversible.
The association between urinary polycyclic aromatic hydrocarbon metabolites and atopic triad by age and body weight in the US population
Published in Journal of Dermatological Treatment, 2022
Sooyoung Kim, Kathryn A. Carson, Anna L. Chien
The underlying mechanisms for the association between PAHs and atopic diseases have been investigated. On a cellular level, PAHs are potent ligands for the aryl hydrocarbon receptor (AhR), a transcription factor expressed in keratinocytes and melanocytes. In an experimental study, epicutaneous application of diesel exhaust particles activates AhR in keratinocytes and upregulate Artn expression, whose product is a neurotrophic factor artemin that is responsible for epidermal hyper-innervation that leads to hypersensitivity and pruritus in atopic dermatitis-like phenotype mice (46). In addition, atopic dermatitis-related genes, Tslp and IL-33, were upregulated after exposure to benzopyrene via AhR activation (46). Studies have shown that PAHs from diesel emission induce a cascade of oxidative stress and mitochondrial damage (47). The exposure to PAHs skewed immune responses toward a Th2 profile, which favors B-cell production of IgE and eosinophils that promote allergic inflammation (48–51). In a study of 256 atopic children (with asthma and/or allergic rhinitis), ambient PAH exposure increased total IgE level, induced epigenetic modifications in FoxP3, a key atopy-related gene, and impaired regulatory T cell function (52).
Anti-Tumor Effect of Vitamin D Combined with Calcium on Lung Cancer: A Systematic Review and Meta-Analysis
Published in Nutrition and Cancer, 2021
Kang Sun, Minghao Zuo, Qin Zhang, Keyi Wang, Dongdong Huang, Honghe Zhang
In addition to the above, vitamin D was also significantly related to lung cancer. Although the lung was not regarded as an organ to metabolize vitamin D, Hansdottir et al. (54) found that airway epithelial cells could transform inactive 25(OH)D3 to 1,25(OH)2D3 that triggered downstream autoimmunity effect through up-regulating the cathelicidin antimicrobial peptide gene and the toll-like receptor. Obviously, lung cancer is a smoking-related cancer, since benzopyrene produced by cigarette combustion is a mutagen and carcinogen. And the work by Matsunawa et al. (13) illustrated that the combination of benzopyrene and VDR enhanced the expression of VDR target gene cytochrome P-45024A1, which inactivated 1,25(OH)2D3. Consequently, high-circulating vitamin D can antagonize the carcinogenic effect of Benzopyrene.
A comprehensive review of cytochrome P450 2E1 for xenobiotic metabolism
Published in Drug Metabolism Reviews, 2019
Jingxuan Chen, Sibo Jiang, Jin Wang, Jwala Renukuntla, Suman Sirimulla, Jianjun Chen
CYP2E1*6 polymorphism is in intron 6 of the gene, related to a nucleotide change, T7632A (Neafsey et al. 2009). Allele and genotype frequencies of CYP2E1*6 vary in different populations. The *6 polymorphism in Asian populations occurs more frequently than in healthy European people, except Northeast Indians (0.8%) (Deka et al. 2010; Kayaalti and Soylemezoglu 2010; Shahriary et al. 2012). The frequency of the variant (12%) in Turkey, is similar to some Asians including Kazakhs (14.5%), Tamilians (15.9%), and Iranians (16.0%), but higher than in other Europeans (4.3%–8.7%) (Arici and Ozhan 2017). It has been reported that there is no significant association between this polymorphism and the susceptibility of urinary cancer (Fang et al. 2017). However, the children who experience high benzopyrene exposure and the variant are associated with increased risk of doctor-diagnosed asthma (Choi et al. 2017).