Table 1.

Specific groups of carcinogens and their DNA damaging mechanisms

Groups	Carcinogens	Mechanisms of DNA damage	References
Radiation	UVA	Direct formation of DNA lesions, oxidation, and damage to DNA repair proteins	[38]
	UVB	↑ CPDs	[39]
	IR	↑ DSBs, secondary effects: generation of abasic sites and SSBs	[40]
PAH	B[a]P	↑ B[a]P diol epoxidation (BPDE) and BPDE–DNA adducts	[41]
	DMBA	↑ Covalent adducts with DNA, formation of depurinated abasic sites within DNA	[42]
HAA	PhIP	↑ DNA adducts: PhIP-C8-dG	[37]
	IQ	↑ IQ-DNA adducts	[43, 44]
N-nitroso-compounds	NDMA	↑ DNA adducts, the conversion into methylamines and induction of o-methylguanine	[45]
Drugs	DXR	↑ DNA DSBs and DNA adducts, ↑ oxygen free radicals	[46]
	MMC	Alkylation DNA, generation DNA cross-links	[47]
	DES	↑ DES-DNA adducts (3′-OH-DES-6′-N3Ade and 3′-OH-DES-6′-N7Gua)	[48]
	ETP	Topoisomerase II inhibitor, ↑ DNA DSBs	[49]
Alkylating agents	MNU/NMU	↑ DNA methylation adducts O(6)-methylguanine, minor products: O2-methylcytosine (O2MeC) and O2-methylthymine (O2MeT)	[50, 51]
	AOM	Mutation in exon 3of Ctnnb gene, constitutive activation of the Wnt pathway	[52]
Mycotoxins	AFB1	↑ AFB1-DNA adducts (AFB1-N(7)-guanine)	[53, 54]
Environmental	Arsenic	DNA repair inhibition, gene expression alterations via epigenetic modifications	[55]

PAH polycyclic aromatic hydrocarbon; HAA heterocyclic aromatic amines; UVA ultraviolet A; UVB ultraviolet B; IR ionising radiation; B[a]P benzo[a]pyrene; DMBA 7,12-dimethylbenz[a]anthracene; PhIP 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine; IQ 2-amino-3-methylimidazo[4,5-f]quinoline; NDMA N-nitrosodimethylamine; DXR doxorubicin; MMC mitomycin C; DES diethylstilbestrol; ETP etoposide; MNU/NMU N-methyl-N-nitrosourea; AOM azoxymethane; AFB1 aflatoxin B1; CPDs cyclobutane pyrimidine dimers; DSBs double-strand breaks; SSBs single-strand breaks

↑increase/induce