Foodborne Mycotoxins as Molecular and Epigenetic Carcinogens: Biochemical Mechanisms and Toxicological Implications

Mycotoxins are toxic secondary metabolites produced predominantly by fungal genera, such as Aspergillus, Fusarium, and Penicillium, and represent major foodborne contaminants responsible for chronic human exposure worldwide. While aflatoxin B1 (AFB1) is a well-established hepatocarcinogen, increasing evidence indicates that multiple mycotoxins contribute to tumorigenesis across diverse organ systems through shared biochemical and molecular mechanisms. At the molecular level, mycotoxins undergo cytochrome P450-mediated bioactivation, generating reactive intermediates that induce DNA adduct formation, oxidative stress, genomic instability, and disruption of redox homeostasis. These events converge on dysregulation of key signaling pathways governing cell-cycle control, apoptosis, immune surveillance, and epigenetic regulation, including aberrant DNA methylation, histone modification, and non-coding RNA expression. Importantly, emerging data support a "dual-hit" paradigm in which mycotoxin exposure synergizes with oncogenic viral infections, such as hepatitis B virus (HBV), human papillomavirus (HPV), and Epstein-Barr virus (EBV), amplifying genotoxic stress, immune evasion, and epigenetic instability. This review synthesizes current mechanistic insights into mycotoxin-induced carcinogenesis, emphasizing molecular toxicological endpoints that link exposure to cancer risk. In addition, advances in biosensing, detoxification, and preventive strategies are discussed, highlighting the need for mechanism-driven interventions to mitigate mycotoxin-associated carcinogenicity and its public health burden.