Search Results (244)

Obesity is increasingly recognized as a complex systemic disorder rather than a simple consequence of excess energy intake and fat accumulation. This review presents a systems biology framework that examines how obesity-driven disruption of inter-organ communication networks contributes to chronic disease susceptibility, with particular emphasis on colorectal cancer (CRC). Disrupted signaling among the brain, adipose tissue, liver, skeletal muscle, gut, and immune system generates maladaptive feedback loops that promote chronic metabolic inflammation (metaflammation), loss of physiological resilience, and progressive metabolic dysfunction. Within this framework, obesity is redefined as a network disease characterized by neuroendocrine dysregulation, adipose tissue remodeling, immune dysfunction, impaired organ crosstalk, and alterations in the gut microbiome. A central feature of this dysregulation is persistent low-grade inflammation driven by immune-metabolic reprogramming and sustained activation of inflammatory pathways. Obesity-associated metaflammation is further linked to accelerated biological aging through mechanisms involving cellular senescence, mitochondrial dysfunction, oxidative stress, and impaired metabolic resilience. These interconnected processes create a tumor-promoting environment by enhancing oncogenic signaling, disrupting intestinal barrier integrity, altering microbial and metabolic signaling, impairing immune surveillance, and promoting epithelial dysfunction, thereby increasing susceptibility to CRC. The review also examines how behavioral, circadian, environmental, and socioeconomic factors influence metabolic health and cancer risk. Finally, emerging translational opportunities, including biomarker-guided risk stratification, precision prevention, metabolic network restoration, and integrative lifestyle and pharmacological interventions, are discussed. Collectively, this review reframes obesity as a whole-body regulatory disorder and provides an integrated conceptual framework linking metabolism, inflammation, aging, and colorectal carcinogenesis to inform future prevention and therapeutic strategies. Full article

Polycyclic aromatic hydrocarbons (PAHs) represent a major class of ubiquitous environmental pollutants, posing significant risks to ecosystems and human health due to their persistence, toxicity, and potential for bioaccumulation. This review provides a comprehensive synthesis of current scientific knowledge on PAHs, integrating insights from chemical kinetics, environmental fate, and toxicological mechanisms. The fundamental structural chemistry of PAHs and its direct influence on their physicochemical properties and environmental properties are discussed. The major anthropogenic and natural sources of PAHs are detailed, alongside the chemical kinetics behind their formation during incomplete combustion and their transformation in environmental media. Unlike previous reviews that address PAH sources, remediation, or health effects as separate topics, this review uniquely traces the mechanistic continuum from molecular formation kinetics through physicochemical partitioning and environmental transport to toxicological endpoints, providing a causally linked framework for understanding how structural properties ultimately determine biological outcomes. A central focus is placed on the environmental fate and transport of PAHs across atmospheric, aquatic, and terrestrial compartments, highlighting processes such as gas–particle partitioning, sediment accumulation, and long-range transport. The review further elucidates the complex toxicological pathways of PAHs, including metabolic activation to reactive intermediates, DNA adduct formation, oxidative stress, and their roles in carcinogenesis and other systemic health effects. The analysis reveals strong scientific consensus on the carcinogenic mechanism of parent PAHs via CYP450-mediated metabolic activation to diol-epoxide intermediates while identifying critical areas of uncertainty: the current regulatory framework based on 16 priority PAHs underestimates total carcinogenic risk by a factor of 2–5, mixture toxicology remains poorly characterized, and dose–response relationships for non-cancer endpoints (cardiovascular, neurodevelopmental, immunotoxic) lack the quantitative data needed for robust risk assessment. Finally, human exposure pathways and health risk characterization approaches are discussed, highlighting the need for cumulative, mixture-based assessment frameworks. Full article

The thyroid gland is particularly vulnerable to the effects of environmental pollutants, due to its high vascularization, dependence on iodine uptake, and intrinsic oxidative environment required for hormone biosynthesis. Therefore, environmental exposure to heavy metals (HMs) and endocrine-disrupting chemicals (EDCs) has emerged as a potential contributor to thyroid dysfunction and carcinogenesis. Despite increasing interest, the clinical relevance of these exposures remains incompletely defined. Available epidemiological data suggest heterogeneous associations across EDCs and HMs classes. While evidence is more consistent for some pollutants, for other compounds it remains limited. Furthermore, while experimental studies provide strong mechanistic support for the key pathways linking environmental exposure to thyroid dysfunction and carcinogenesis, the clinical interpretation of epidemiological data is constrained by important methodological limitations. This narrative review aims to integrate current epidemiological and experimental evidence on the role of HMs and EDCs in thyroid diseases, including both non-neoplastic disorders and thyroid cancer, examining their environmental distribution, exposure pathways, and biological effects. Full article

Background: Oral squamous cell carcinoma (OSCC) remains a major public health challenge, particularly in South Asian populations where environmental exposures such as tobacco and areca nut consumption contribute significantly to disease burden. Although genomic studies have improved understanding of oral cancer biology, population-specific genomic data from high-risk Indian populations remain limited. This study aimed to characterize the genomic landscape of OSCC using whole-exome sequencing (WES) of fresh biopsy specimens obtained from patients residing along the southwest coast of Karnataka, India. Methods: Paired tumor and adjacent normal tissues from ten OSCC samples (total n = 20 samples) were subjected to WES to identify somatic and germline-associated variants. Matched tumor–normal comparative analysis, variant annotation, and population frequency assessment using established genomic databases, including gnomAD, were performed to characterize the mutational profile. The findings were further compared with a previously analyzed regional cohort comprising 66 OSCC patients to evaluate recurrence patterns and population relevance. Results: The analysis identified a broad background of recurrent germline-associated variants alongside a comparatively limited number of tumor-specific somatic mutations, consistent with the expected predominance of constitutional genetic variation relative to acquired coding alterations in tumor samples. Recurrent variants were observed in genes associated with DNA repair, immune signaling, inflammatory responses, and pharmacogenomic pathways, including XRCC1, ITPKB, ABCB1, and OPRM1, whereas somatic alterations were primarily detected in established cancer-associated genes such as TP53, CDKN2A, and TERT. Conclusions: Several recurrent variants demonstrated high frequencies in South Asian populations, suggesting that they may represent recurrent population-associated variants of potential biological or pharmacogenomic relevance that require validation in larger cohorts. KEGG pathway enrichment analysis identified pathways related to cancer, chemical carcinogenesis, metabolic regulation, and xenobiotic response. Overall, these findings provide preliminary insights into the population-specific genomic characteristics of OSCC in this regional cohort and highlight the need for larger validation studies to determine the biological significance and reproducibility of these findings. Full article

The active vitamin D metabolite, 1,25-dihydroxycholecalciferol [1,25(OH)₂D], exerts its biological effects through binding to the vitamin D receptor (VDR), a ligand-activated transcription factor regulating the expression of genes involved in calcium and phosphate homeostasis, immune modulation, and cell proliferation and differentiation. In addition to direct transcriptional regulation, 1,25(OH)₂D signaling also involves epigenetic mechanisms. A total of 90 studies were included in this narrative review, comprising experimental studies (n = 45), observational studies (n = 17), population-based studies (n = 8), interventional studies (n = 15), and mixed-design studies (n = 5). Experimental studies in cell cultures and animal models demonstrate that 1,25(OH)₂D may affect several major epigenetic regulatory pathways, including chromatin remodeling, DNA methylation, histone modifications, and the expression of non-coding RNAs, particularly microRNAs. Preclinical evidence suggests that the epigenetic actions of 1,25(OH)₂D are involved in metabolic regulation, immune responses, bone development, fibrotic processes, carcinogenesis, ageing, and fetal programming. However, evidence from observational studies and randomized controlled trials remains limited and inconclusive. Some studies have reported alterations in miRNA expression, methylation of selected loci, and epigenetic age markers. The clinical relevance of 1,25(OH)₂D–mediated epigenetic regulation has not yet been fully established. The interpretation of available findings is limited by substantial heterogeneity in study populations, exposure and intervention protocols, environmental factors, interindividual variability in response to vitamin D supplementation associated with genetic polymorphisms and methylation status, and the restricted range of analyzed cell types. This subject requires randomized controlled trials integrating molecular endpoints with clinically relevant outcomes. Full article

The rising incidence of early-onset colorectal cancer (CRC) remains incompletely explained despite extensive investigation into genetic, environmental and metabolic factors. Emerging evidence suggests that infectious agents may contribute to colorectal carcinogenesis. A recent study by Tehrani et al. demonstrated the presence of Mycobacterium avium subspecies paratuberculosis (MAP) in a majority of colorectal cancer lesions and in approximately half of precancerous lesions, providing a critical epidemiologic anchor. MAP, a zoonotic intracellular pathogen long associated with Crohn’s disease, exhibits biological features consistent with inflammation-driven carcinogenesis, including persistence, immune modulation and systemic dissemination. Mechanistically, MAP infection may promote tumorigenesis through chronic mucosal inflammation, epithelial barrier disruption and activation of human endogenous retroviruses (HERVs) linking persistent infection to genomic instability. Detection of MAP in early lesions argues against secondary colonization and supports a potential initiating or promoting role. Within a One Health framework, MAP represents a plausible, pleiotropic and potentially modifiable contributor to CRC. While causality remains unproven, the convergence of epidemiologic association, mechanistic plausibility and early lesion involvement warrants rigorous investigation. Full article

Background: Radon exposure is the second most important risk factor for lung cancer after tobacco smoking and represents a significant but often underestimated public health problem. Due to the absence of specific clinical manifestations at early stages, the identification of molecular biomarkers reflecting early radon-induced carcinogenic processes is of particular importance. The aim of this study was to identify protein biomarkers associated with radon exposure in lung cancer patients residing in settlements of the Akmola and North Kazakhstan regions of Kazakhstan. Methods: Indoor radon exposure was assessed using CR-39 detectors to measure radon concentrations in residential dwellings during summer and autumn periods. The study included 57 lung cancer patients and 73 control subjects residing in areas characterized by varying levels of radon exposure. Plasma samples were collected and analyzed using liquid chromatography–tandem mass spectrometry (LC–MS/MS) to identify differentially expressed proteins associated with lung cancer and radon exposure. Statistical analyses were performed to evaluate differences between groups and associations between radon exposure and molecular biomarkers. Results: Seasonal variability in indoor radon concentrations was observed, with several settlements demonstrating levels exceeding international reference values. Proteomic analysis identified multiple proteins differentially expressed between lung cancer patients and controls, as well as between radon-exposed and non-exposed lung cancer patients. Several proteins involved in inflammation, lipid metabolism, oxidative stress, and immune regulation pathways demonstrated significant differences in expression levels, suggesting potential associations with radon-induced carcinogenic mechanisms. LC–MS/MS proteomic profiling identified multiple differentially expressed proteins associated with lung cancer and radon exposure after false discovery rate correction. Proteins involved in inflammation, oxidative stress, immune regulation, and lipid metabolism, including ORM2, AZGP1, PRDX2, IRF7, and APOC3, demonstrated significant expression differences between radon-exposed and low-exposure groups. Conclusions: The identified protein biomarkers demonstrated significant associations with both radon exposure and lung cancer status, indicating their potential relevance for early detection and risk assessment of radon-induced lung cancer. The integration of environmental exposure assessment with proteomic profiling may provide new insights into the molecular mechanisms of radon-associated carcinogenesis and support the development of preventive strategies. Full article

Biomolecular condensates in the cytoplasm and nucleus contribute to carcinogenesis through aberrant signaling by assorted transcription factors and fusion oncoproteins. Oral cancer, which is highly prevalent worldwide, frequently occurs in a U-shaped “high-risk” zone (floor of mouth, side of tongue, and anterior fauces) which forms the path of liquid transit through the mouth. We previously reported that environmental stresses of saliva-like hypotonicity and beverage-like temperature changes triggered cycles of disassembly/reassembly of biomolecular condensates of GFP-tagged human myxovirus resistance protein (MxA; alias Mx1) in oral cancer cells. In the present study, we identified some of the constituents of GFP-MxA cytoplasmic condensates in oral cells. These condensates were isolated from interferon (IFN)-λ1-treated GFP-MxA expressing OECM1 human oral cancer cells using magnetic bead-based immunoisolation. Unbiased peptide identification confirmed the presence of MxA/Mx1 peptides; however, the strongest intensity was for the BACH1 transcription factor family. Immunofluorescence analyses confirmed the association of BACH1 and the family member Nrf2 with cytoplasmic human GFP-MxA condensates. Moreover, GFP-BACH1 and GFP-Nrf2 colocalized with cytoplasmic human HA-MxA condensates in transiently transfected OECM1 cells. Western blot assays confirmed the presence of BACH1 and Nrf2 proteins in complexes isolated using anti-MxA pAb. As much as BACH1 and Nrf2 regulate oxidative stress response genes, it was remarkable that immunofluorescence assays revealed the presence of heme oxygenase 1 (HO1)—a downstream redox regulator—in GFP-MxA condensates. However, these condensates were devoid of p62, KEAP1 and Cul3. In terms of aberrant function, in live cells, the Nrf2 transcription factor underwent rapid disassembly and reassembly cycles driven by saliva-like hypotonicity, and was also disassembled by sulforaphane. The data highlight the unexpected intersections in oral cells between MxA condensates and BACH1, Nrf2 and HO1—proteins well known to be involved in pathways regulating cellular responses to environmental and oxidative stresses, antiviral defense, oral epithelial dysplasia, and cancer progression and metastases. Full article

CRC remains a major cause of cancer-related morbidity and mortality worldwide. In recent years, the gut microbiota has gained increasing attention in CRC research. Intestinal microbes are not passive bystanders in tumor development. They may promote persistent inflammation, disrupt epithelial barrier integrity, alter microbial metabolites, and affect host immune and signaling pathways. Emerging evidence also suggests that microbiota-related metabolites and microbial functional alterations may influence host epigenetic regulation, including DNA methylation and chromatin-associated signaling, thereby further shaping colorectal carcinogenesis. Together, these changes can create a microenvironment that favors tumor initiation and progression. Several bacterial species, including Fusobacterium nucleatum, Parvimonas micra, and Peptostreptococcus anaerobius, have been repeatedly associated with CRC. In contrast, beneficial commensal microbes and their metabolites, especially short-chain fatty acids, may help maintain intestinal homeostasis and limit tumor-promoting processes. Because the gut microbiota is strongly shaped by diet, lifestyle, and environmental exposure, regional differences are also relevant. This is particularly important in Sichuan, China, where distinctive dietary habits and environmental features may influence microbial patterns associated with CRC risk and disease behavior. This review summarizes the main mechanisms linking the gut microbiota to CRC, examines the regional context of Sichuan, China, and discusses current and emerging clinical strategies. These include dietary intervention, probiotics, fecal microbiota transplantation, and microbiome-informed approaches to prevention, diagnosis, and treatment. Full article

The pancreas is an organ with two functions: endocrine and exocrine. The proper functioning of the pancreas depends on many factors. One of these is trace elements—precise control of trace element homeostasis is important for both the endocrine and exocrine parts. This review provides a comprehensive summary of current knowledge regarding the role of trace elements: iron (Fe), copper (Cu), cobalt (Co), iodine (I), manganese (Mn), zinc (Zn), silver (Ag), cadmium (Cd), mercury (Hg), lead (Pb), and selenium (Se) in pancreatic physiology and their influence on the pathogenesis of key diseases of this organ, such as diabetes (DM), acute (AP) and chronic pancreatitis (CP), autoimmune pancreatitis (AIP), and pancreatic cancer (PC). Trace elements, including Fe, Cu, Zn, Se, and Mn, play a fundamental role in maintaining endocrine and exocrine homeostasis, participating in insulin synthesis, stabilizing digestive enzymes, and the functioning of antioxidant systems. It has been demonstrated that disturbances in their concentrations lead to the activation of pathological molecular pathways, including oxidative stress, chronic inflammation, and beta-cell apoptosis. In the context of diabetes, excess Fe promotes ferroptosis, whilst exposure to heavy metals such as Cd, Pb, and Hg induces insulin resistance and pancreatic islet dysfunction. In the course of pancreatitis, elements such as Zn and Se exhibit protective potential by stabilizing tissue barriers, whereas toxic metals impair ion transport, exacerbating fibrotic processes. Furthermore, analysis of available data indicates a significant association between heavy metal accumulation and pancreatic carcinogenesis, driven by DNA damage and oncogene modulation. Understanding pancreatic metallomics opens new prospects for early diagnosis, environmental prevention, and the development of targeted therapeutic strategies that restore the body’s micronutrient balance. Full article

Background/Objectives: Radon exposure has recently been associated with asthma morbidity, including increased airway inflammation and school absenteeism in children, though limited data on underlying biological mechanisms exist. Interleukin-6 (IL-6), a pleiotropic cytokine implicated in both Type 2-low airway inflammation and radon-related lung carcinogenesis, may represent a key mechanistic link between radon exposure and asthma morbidity. We aimed to evaluate the association between indoor radon exposure and plasma IL-6 levels in children with asthma and whether this relationship differs by allergic sensitization status. Methods: We analyzed baseline data from the School Inner-City Asthma Study, a prospective cohort of children aged 4–13 years with persistent asthma. Monthly indoor radon concentrations at each participant’s residential ZIP Code Tabulation Area were estimated using a validated spatiotemporal prediction model. Plasma IL-6 was measured from baseline blood samples. Multivariable linear mixed-effects models with random intercepts for school were used to assess the association between radon exposure and IL-6, adjusting for demographic, clinical, and socioeconomic covariates. Effect modification by allergic sensitization was evaluated using an interaction term. Results: Among 144 participants, 62.5% were allergen-sensitized. The median home radon concentration was 46.6 Bq/m³ (range 30.7–99.9), and the mean plasma IL-6 was 0.22 pg/mL (SD 0.41). A significant interaction was observed between radon exposure and allergic sensitization status (β-interaction = −0.012; p = 0.014), indicating differential effects by phenotype. Among non-sensitized children, higher radon exposure was associated with increased IL-6 levels (β = 0.0088; p = 0.044), corresponding to a 0.32 pg/mL rise in IL-6 per 37 Bq/m³ increase in radon. No significant association was observed among sensitized children. Conclusions: Indoor radon exposure is associated with higher plasma IL-6 levels in non-sensitized children with asthma, suggesting a potential IL-6–mediated pathway linking radon exposure to asthma morbidity in the Type 2-low phenotype. These findings highlight heterogeneity in environmental asthma responses and support further investigation into radon mitigation as a modifiable factor to improve asthma outcomes. IL-6 may serve as a biomarker to identify children most susceptible to radon-related airway inflammation, guiding personalized mitigation strategies and targeted interventions to improve asthma outcomes. Future studies should incorporate direct home radon measurements, comprehensive endotyping panels, and longitudinal biomarker sampling to validate these findings and elucidate whether IL-6 trans-signaling pathways mediate radon-induced airway injury in non-allergic asthma. Full article

Colorectal cancer (CRC) is a multifactorial disease influenced by genetic and environmental factors. The endothelial nitric oxide synthase (eNOS) gene, involved in nitric oxide (NO) production, is associated with carcinogenesis. This study aimed to evaluate the association between eNOS −786T>C and G894T polymorphisms and CRC susceptibility in an Algerian population. Genotype and allele frequencies were analyzed, and associations were assessed using odds ratios (ORs) and 95% confidence intervals (CIs). For −786T>C polymorphism, the CC genotype was significantly more frequent in patients than in controls (37.33% vs. 21.67%) and was associated with increased risk of CRC (OR = 2.15, 95% CI: 1.21–3.88, p = 0.004), whereas the TT genotype showed a protective effect (OR = 0.41, 95% CI: 0.20–0.81, p = 0.005). Regarding the G894T polymorphism, the TT genotype was significantly associated with increased susceptibility to CRC (44.67% vs. 8.33%; OR = 8.88, 95% CI: 4.19–15.40, p < 0.001), while the GG genotype was protective (OR = 0.18, 95% CI: 0.10–0.32, p < 0.001). Allelic analysis confirmed that the C and T alleles were risk factors. Furthermore, eNOS polymorphisms were significantly associated with tumor location. In conclusion, the eNOS −786T>C and G894T polymorphisms are significantly associated with CRC susceptibility in the Algerian population and could serve as potential genetic biomarkers. Full article

Background and Objectives: Gastric cancer remains a leading cause of cancer-related mortality worldwide and develops through complex interactions between environmental factors, microbial dysbiosis, and host molecular pathways. Although Helicobacter pylori infection is a well-established risk factor, emerging evidence suggests that broader alterations in the gastric microbiome may also contribute to carcinogenesis. However, the associations between gastric cancer-associated microbial taxa and host gene expression profiles remain insufficiently characterized. This study aimed to identify host gene signatures associated with gastric cancer-related microbial taxa through a descriptive analysis integrating microbiome-derived taxa with transcriptome data. Materials and Methods: Microbial taxa associated with gastric cancer were systematically retrieved from the Disbiome database. Taxon set enrichment analysis (TSEA) was performed using the MicrobiomeAnalyst platform to identify host genes associated with gastric cancer-associated taxa. Importantly, TSEA relies on healthy reference data from the Human Microbiome Project and does not establish gastric cancer-specific interactions or causal relationships. Gene expression levels were subsequently evaluated using The Cancer Genome Atlas (TCGA) PanCancer stomach adenocarcinoma (STAD) dataset by comparing tumor and matched normal gastric tissues. Gene interaction network and transcription factor (TF) enrichment analyses were conducted to explore predicted regulatory relationships. Results: Among 64 microbial taxa associated with gastric cancer, 43 were reported as elevated. After removing overlapping taxa across studies, 37 elevated and 21 reduced taxa were retained for analysis. TSEA identified 11 host genes associated with gastric cancer-related microbial taxa. Transcriptomic analysis demonstrated significant downregulation of DPP6 and DLG2, while KDM4D, USP34, and VDR were significantly upregulated in gastric cancer tissues compared with normal controls. Network and TF enrichment analyses revealed predicted co-expression and co-localization patterns among these genes, suggesting their potential involvement in immune-related processes, epigenetic regulation, and cellular organization. Conclusions: This descriptive study identifies distinct host gene expression signatures associated with gastric cancer-associated microbial dysbiosis. This study is purely associative and hypothesis-generating; no causal or mechanistic inferences are made. TSEA used healthy reference data and therefore does not reflect gastric cancer-specific host–microbe interactions. The findings provide a basis for future hypothesis-driven research but require validation in independent cohorts. Full article

Accounting for over 1.2 million new diagnoses worldwide in 2022, non-melanoma skin cancer (NMSC) represents the most common human cancer, predominantly manifesting as basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). NMSC serves as a powerful natural model for studying how environmental exposure, the exposome, reprograms the epigenome to drive carcinogenesis. Chronic ultraviolet radiation (UVR), the dominant risk factor, induces DNA damage and inflammation that dysregulate epigenetic enzymes (e.g., DNMTs, HDACs). These effects are layered with perturbations from β-HPV infection and cutaneous dysbiosis, altering DNA methylation, histone modifications, and non-coding RNA and miRNA expression in a multistep carcinogenic process. This review synthesizes the central role of epigenetic regulation as the critical interface between genetic susceptibility and cumulative exposome factors in NMSC pathogenesis. We integrate how UVR, HPV, and inflammation converge to remodel the keratinocyte epigenome. Finally, we evaluate the translational potential of this knowledge for refined risk stratification through epigenetic biomarkers and discuss emerging therapeutic strategies, including epidrugs, that target these dysregulated pathways for advanced NMSC management. Full article

Cervical cancer (CC) is a complex, multistep process involving various viral, molecular, cellular, endogenous, and environmental events that transform normal cervical epithelium into a malignant tumor through a cascade of events. The contribution of high-risk human papillomavirus (HPV) to cancer is significant but involves many additional mechanisms such as oxidative stress (OS), arrested apoptosis of non-functional intraepithelial neoplastic cells, senescence-associated secretory phenotype (SASP), and the final epithelial–mesenchymal transition (EMT) of cervical epithelial neoplasia (CIN) cells. While high-risk HPV oncoproteins E6 and E7 are widely recognized as the primary triggers of CC, the critical role of E6 in degrading the p53 regulatory protein, thereby inhibiting the apoptosis of reactive oxygen species (ROS)-damaged neoplastic cells, is frequently underappreciated in the gynecological literature. Arrested apoptosis of non-functional neoplastic intraepithelial cells is a key event in cervical carcinogenesis and the biological basis of CIN progression via SASP senescence and ultimately EMT. While recent reviews touched upon each of the reviewed aspects, this review aims to provide a general understanding of all links in this complex molecular-biological chain, from HPV infection, oxidative stress, arrested apoptosis, SASP, and EMT. Beyond providing an encompassing primer for clinical researchers, we additionally review potential oxidative stress-related markers for shifting the classic diagnostic and therapeutic paradigms of CIN and cervical cancer. Full article