Table 1.

In vitro studies on the effects of Pb on the expression of DNA repair-related genes.

Test System	Substance	Treatment	DNA Repair Gene	Method	Result	Reference
Mouse embryonic stem (mES) cells	Lead acetate	0.02 mg/mL for 1 h	OGG1, Top3a, Rad18	RT-PCR	Significant down-regulation	Gadhia et al. (2012) [9]
CL3 human lung cancer cells	Lead acetate	10–100 µM for 30 min, and 24 h	APE1	Western blot	Significant increase in APE1 protein level in a dose-dependent manner	Wang et al. (2013) [34]
Stem cells from dental origin	Lead nitrate	160 µM for 24 h	ERCC3, XRCC4, RAD51	RT-PCR	No significant change	Abdullah et al. (2014) [33]
Lymphoblastoid TK6 cells	Lead acetate	120 µM for6–24 h	XRCC1, hOGG-1, BRCA1, XPD	Western blot	Significant decreases in protein levels of XRCC1 at 12 h; hOGG-1 at 6, 12, and 24 h; BRCA1 at 12 and 24 h; and XPD at 6 and 12 h	Liu et al. (2018) [31]
Roots of A. cepa var. agrogarum	Lead nitrate	5.0 and 15.0 µM for 12 h	POLD1	RT-PCR and MS	Significant down-regulation	Lyu et al. (2020) [32]

RT-PCR: reverse transcription-polymerase chain reaction; MS: mass spectrometry; OGG1: 8-oxoguanine DNA glycosylase 1; Top3a: DNA topoisomerase 3-alpha; Rad18: E3 ubiquitin-protein ligase RAD18; APE1: AP endonuclease; ERCC3: Excision Repair 3; XRCC4: X-ray repair cross-complementing protein 4; RAD51: RAD51 Recombinase; XRCC1: X-ray repair cross-complementing protein 1; BRCA1; Breast Cancer gene 1; XPD: xeroderma pigmentosum group D; and POLD1: DNA Polymerase Delta 1.