Benzo[a]pyrene in Moscow road dust: pollution levels and health risks

TGFBR2 as a prognostic marker and therapeutic target in benzo(a)pyrene-associated esophageal cancer: insights from multi-omics analysis

BACKGROUND

Benzo(a)pyrene (BaP) is an environmental pollutant linked to several cancers, including esophageal cancer (ESCA). Understanding its impact on gene expression and associated molecular pathways in ESCA is crucial for developing targeted therapies.

METHODS

Using the TCGA-ESCA dataset, we identified differentially expressed genes (DEGs) related to BaP exposure. Enrichment analyses and protein-protein interaction (PPI) network construction were performed to explore the biological significance of these DEGs. Molecular docking studies assessed the interactions between BaP and core subnetwork genes. Survival analysis and immune cell infiltration analysis were conducted to evaluate the prognostic value of TGFBR2. Chemotherapy drug sensitivity was analyzed based on TGFBR2 expression levels.

RESULTS

We identified 5757 DEGs in ESCA, with 33 genes linked to both BaP exposure and ESCA. Enrichment analyses revealed significant pathways, including p53 signaling and apoptosis. Key genes (ACTB, CDKN2A, TGFBR2) were verified for their differential expression. Molecular docking demonstrated strong BaP binding to several core proteins. High TGFBR2 expression correlated with better survival, enhanced immune infiltration, and altered sensitivity to chemotherapeutic agents.

CONCLUSION

Our study highlights the molecular mechanisms by which BaP influences ESCA, with TGFBR2 emerging as a potential prognostic marker and therapeutic target. These insights pave the way for personalized treatments in BaP-induced esophageal carcinogenesis.

Contamination assessment and source identification of metals and metalloids in submicron road dust (PM1) in Moscow Megacity

The content of 39 metals and metalloids (MMs) in submicron road dust (PM1 fraction) was studied in the traffic zone, residential courtyards with parking lots, and on pedestrian roads in parks in Moscow. The geochemical profiles of PM1 vary slightly between different types of roads and courtyards but differ significantly from those in parks. In Moscow, compared to other cities worldwide, submicron road dust contains less As, Sb, Mo, Cr, Cd, Sn, Tl, Ca, Rb, La, Y, U, but more Cu, Zn, Co, Fe, Mn, Ti, Zr, Al, V. Relative to the upper continental crust, PM1 is highly enriched in Sb, Zn, Cd, Cu, W, Sn, Bi, Mo, Pb. In the courtyards, where contact between pollutants and the population is most frequent and occurs over an extended period, the level of PM1 pollution with MMs (from strong to extreme) is comparable to that on large roads. Source identification was conducted using correlations, elemental ratios, and absolute principal component analysis with multiple linear regression (APCA-MLR). In the traffic zone, non-exhaust and exhaust vehicle emissions contribute significantly to the MM concentrations in PM1 (especially for Bi, Sb, Sn, V, Fe, Cu, W, Mo); soil particles, abrasion of steel surfaces, industrial emissions, tire and road wear with carbonate dust resuspension contribute less. In the courtyards, the contribution of the road wear with carbonate dust resuspension and soil particles increases by up to 16% due to the poor condition of the road surface, frequent construction works, and large contact areas of roads with soils. In parks, the contribution of anthropogenic sources sharply decreases by 20-48% due to the increased soil resuspension rate. The spatial distribution pattern of MMs in submicron road dust should aid in the development of more effective road surface washing strategies, ultimately minimizing the risk to public health.

Baseline concentrations and quantitative health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in relation to particle grain size in street dust of Warsaw Poland

Total concentrations, toxicity, and health risks of 16 polycyclic aromatic hydrocarbons (PAH) in street dust from Warsaw (Poland) in 6 granulometric fractions were investigated. Street dust was collected from 149 sampling points distributed among Area 1 (central districts, left bank of the Vistula River, mostly traffic-related pollution) and Area 2&3 (suburb area, mostly residential, right bank of the river). Street dust was investigated before ("all") and after separating into 5 size-dependent samples: (1-0.8 mm) "0.8", (0.8-0.6 mm) "0.6", (0.6-0.4 mm) "0.4", (0.4-0.2 mm) "0.2", and (below 0.2 mm) " < 0.2". ΣPAH mean concentration was 3.21 mg/kg for Area 1 and 0.89 mg/kg for Area 2&3. ∑BaPTPE values calculated collectively for Area 1&2&3 were observed to be 318.3, 83.5, 131.1, 81.4, 164.3, and 339.7 ng/g for "all", "0.6", "0.4", "0.2", and " < 0.2", respectively. Significant differences in ∑BaPTPE values were observed between fractions and specific areas. The cancer risk levels for children and adults, for all particulate size fractions, were comparable for dermal contact and by ingestion and ranged from 10-5 to 10-4, whereas the cancer risk levels via inhalation always ranged from 10-10 to 10-8. Therefore, inhalation of resuspended street dust is almost negligible compared to other pathways. Environmental implication. Street dust pollution in cities is one of the most important issues in the world and it negatively affects the quality of the environment and people's health. This study contributed to filling the gap in knowledge about the characteristics of PAH contaminants in the subject of the grain size of street dust from Poland and assessing the potential health risks. Therefore, our work has provided new significant information on PAH pollution, methods of measuring PAHs content and assessing the risk to human health, which may be useful to the scientific community, policymakers, and the general public.

Human CYP1A1-activated aneugenicity of aflatoxin B1 in mammalian cells and its combined effect with benzo(a)pyrene

Aflatoxin B1 (AFB1) is the most toxic mycotoxin and a proven human carcinogen that requires metabolic activation, known by cytochrome P450 (CYP) 1A2 and 3A4. Previous evidence showed that AFB1 is activated by human recombinant CYP1A1 expressed in budding yeast. Yet, the toxicity, in particular the genotoxicity of the reactive metabolites formed from AFB1 remains unclear. Humans could be exposed to both AFB1 and benzo(a)pyrene (BaP) simultaneously, thus we were interested in their combined genotoxic effects subsequent to metabolic activation by CYP1A1. In this study, molecular docking of AFB1 to human CYP1A1 indicated that AFB1 is valid as a substrate. In the incubations with AFB1 in human CYP1A1-expressed microsomes, AFM1 as a marking metabolite of AFB1 was detected. Moreover, AFB1 induced micronucleus formation in a Chinese hamster V79-derived cell line and in a human lung epithelial BEAS-2B cell line, both expressing recombinant human CYP1A1, V79-hCYP1A1 and 2B-hCYP1A1 cells, respectively. Immunofluorescence of centromere protein B stained micronuclei was dominant in AFB1-treated BEAS-2B cells exposed to AFB1, suggesting an aneugenic effect. Moreover, AFB1 elevated the levels of ROS, 8-OHdG, AFB1-DNA adduct, and DNA breaks in 2B-hCYP1A1 cells, compared with those in the parental BEAS-2B cells. Meanwhile, AFB1 increased CYP1A1, RAD51, and γ-H2AX protein levels in 2B-hCYP1A1 cells, which were attenuated by the CYP1A1 inhibitor bergamottin. Co-exposure of AFB1 with BaP increased 8-OHdG, RAD51, and γ-H2AX levels (indicating DNA damage). In conclusion, AFB1 could be activated by human CYP1A1 for potent aneugenicity, which may be further enhanced by co-exposure to BaP.

Mechanisms and targeted reversion/prevention of hepatic fibrosis caused by the non-hereditary toxicity of benzo(a)pyrene

The effect of long term exposure to low concentrations of environmental pollutants on hepatic disorders is a major public health concern worldwide. Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants. In recent years, an increasing number of studies have focused on the deleterious effects of low concentrations of PAHs in the initiation or exacerbation of the progression of chronic liver disease. However, the underlying molecular mechanisms and effective intervention methods remain unclear. Here, we found that in hepatocytes, a low concentration of benzo(a)pyrene (B[a]P, an indicator of PAHs) chronic exposure continuously activated 14-3-3η via an epigenetic accumulation of DNA demethylation. As a "switch like" factor, 14-3-3η activated its downstream PI3K/Akt signal, which in turn promoted vascular endothelial growth factor (VEGF) production and secretion. As the characteristic fibrogenic paracrine factor regulated by B[a]P/14-3-3η, VEGF significantly induced the neovascularization and activation of hepatic stellate cells, leading to the development of hepatic fibrosis. Importantly, targeted 14-3-3η by using its specific inhibitor invented by our lab could prevent B[a]P-induced hepatic fibrosis, and could even reverse existent hepatic fibrosis caused by B[a]P. The present study not only revealed novel mechanisms, but also proposed an innovative approach for the targeted reversion/prevention of the harmful effects of exposure to PAHs on chronic liver disease.