Specific long non-coding RNAs response to occupational PAHs exposure in coke oven workers

Abstract

To explore whether the alteration of lncRNA expression is correlated with polycyclic aromatic hydrocarbons (PAHs) exposure and DNA damage, we examined PAHs external and internal exposure, DNA damage and lncRNAs (HOTAIR, MALAT1, TUG1 and GAS5) expression in peripheral blood lymphocytes (PBLCs) of 150 male coke oven workers and 60 non-PAHs exposure workers. We found the expression of HOTAIR, MALAT1, and TUG1 were enhanced in PBLCs of coke oven workers and positively correlated with the levels of external PAHs exposure (adjusted P_trend < 0.001 for HOTAIR and MALAT1, adjusted P_trend = 0.006 for TUG1). However, only HOTAIR and MALAT1 were significantly associated with the level of internal PAHs exposure (urinary 1-hydroxypyrene) with adjusted β = 0.298, P = 0.024 for HOTAIR and β = 0.090, P = 0.034 for MALAT1. In addition, the degree of DNA damage was positively associated with MALAT1 and HOTAIR expression in PBLCs of all subjects (adjusted β = 0.024, P = 0.002 for HOTAIR and β = 0.007, P = 0.003 for MALAT1). Moreover, we revealed that the global histone 3 lysine 27 trimethylation (H3K27me3) modification was positively associated with the degree of genetic damage (β = 0.061, P < 0.001) and the increase of HOTAIR expression (β = 0.385, P = 0.018). Taken together, our findings suggest that altered HOTAIR and MALAT1 expression might be involved in response to PAHs-induced DNA damage.

Keywords: 1-OHP, 1-hydroxypyrene; 1-hydroxypyrene (PubChem CID: 21387); DNA damage response; GAS5, growth arrest-specific 5; H2K27me3, histone 3 lysine 27 trimethylation; HOTAIR; HOTAIR, HOX transcript antisense RNA; Long non-coding RNA; MALAT; MALAT1, metastasis-associated lung adenocarcinoma transcript 1; PAHs, polycyclic aromatic hydrocarbons; PBLCs, peripheral blood lymphocytes; Peripheral blood lymphocytes; Polycyclic aromatic hydrocarbons; TUG1, taurine up-regulated 1; lncRNAs, long non-coding RNAs.

Fig. 1

Association between PAHs exposure and lncRNA expression in PBLCs of the subjects. The PAHs-exposed workers were divided into three subgroups as bottom, side, and top oven, where the level of PAHs exposure went up from bottom to top. LncRNA expression was tested by qRT-PCR method. The horizontal line in the box represents the median of each subgroup. (A) HOTAIR, P_trend < 0.001; (B) TUG1, P_trend = 0.002; (C) MALAT1, P_trend < 0.001; (D) GAS5, P_trend = 0.809.

Fig. 2

The correlation between urinary 1-OHP and lncRNA expression in PBLCs of all subjects. LncRNA expression levels (Y-axis) were presented as −ΔCt = −(Ct_targetgene − Ct_GAPDH − ΔCt_batchbalance). Urinary 1-OHP (X-axis) was presented as log-transformed value. (A) HOTAIR, y = 0.3431x − 13.7423, R = 0.1824, P = 0.008; (B) TUG1, y = 0.1086x − 4.7992, R = 0.1330, P = 0.054; (C) MALAT1, y = 0.1134x − 0.5052, R = 0.1840, P = 0.008; (D) GAS5, y = 0.0001x − 0.8388,R = 0.0572,P = 0. 409.

Fig. 3

Enhanced H3K27me3 modification was correlated to the degree of DNA damage and upregulation of HOTAIR expression. The modification of H3K27me3 was examined by ELISA. The degree of DNA damage was indicated by Olive tail moment (OTM) from Comet assay. LncRNA expression was tested by qRT-PCR. (A) Association of H3K27me3 modification with OTM in PBLCs of all subjects. y = 0.0606x + 9.9009, R = 0.2540, P < 0.001. (B) Association of H3K27me3 modification with HOTAIR expression in PBLCs of all subjects. y = 0.0182x + 16.5407, R = 0.1629, P = 0.018.