Association of Genetic Polymorphisms, mRNA Expression of p53 and p21 with Chronic Benzene Poisoning in a Chinese Occupational Population

DOI: 10.1158/1055-9965.EPI-09-0140 Published June 2009

Article Figures & Data

Table 1.

Characteristics of selected demographic and exposure variables in CBP cases and controls

Table 2.

Genotypes for genetic polymorphisms in p53 and p21 and their effects on risk of CBP

Genotype	Cases (%)*	Controls (%)*	OR (95% CI)	OR_adj. (95% CI)^†
P53 intron 3^‡
WW	280 (94.6)	258 (92.8)	1.00	1.00
WM	16 (5.4)	20 (7.2)	0.74 (0.37-1.45)	% (0.22-1.58)
MM	0 (0.00)	0 (0.0)	–	–
WM+MM	16 (5.4)	20 (7.2)	0.74 (0.37-1.47)	% (0.22-1.58)
P53 C119G
CC	56 (18.7)	51 (17.8)	1.00	1.00
CG	144 (48.0)	142 (49.5)	0.92 (0.59-1.44)	1.04 (0.58-1.87)
GG	100 (33.3)	94 (32.8)	0.97 (0.60-1.55)	0.87 (0.46-1.63)
CG+GG	244 (81.3)	236 (82.2)	0.94 (0.62-1.43)	0.97 (0.55-1.69)
P53 IVS6+62 G>A
GG	272 (89.8)	265 (90.1)	1.00	1.00
GA	31 (10.2)	29 (9.9)	1.04 (0.61-1.78)	1.28 (0.63-2.57)
AA	0 (0.00)	0 (0.0)	–	–
GA+AA	31 (10.2)	29 (9.9)	1.04 (0.61-1.78)	1.28 (0.63-2.57)
P21 C98A
CC	100 (33.0)	65 (22.5)	1.00	1.00
CA	158 (52.2)	173 (59.9)	0.59 (0.41-0.87)^§	0.48 (0.29-0.79)^§
AA	45 (14.9)	51 (17.6)	0.57 (0.35-0.95)^∥	0.67 (0.33-1.35)
CA+AA	203 (67.0)	224 (77.5)	0.59 (0.41-0.85)^§	0.51 (0.32-0.83)^§
P21 C70T
CC	66 (21.9)	45 (15.4)	1.00	1.00
CT	104 (34.6)	107 (36.6)	0.66 (0.42-1.06)	0.56 (0.29-1.06)
TT	131 (43.5)	140 (48.0)	0.64 (0.41-1.00)^∥	0.51 (0.28-0.94)^∥
CT+TT	235 (78.1)	247 (84.6)	0.65 (0.43-0.99)^∥	0.53 (0.29-0.95)^∥

↵* Data missing due to failure in DNA amplification.
↵† ORs were adjusted for potential confounders including gender, cigarette smoking, alcohol consumption, exposure duration, and intensity of benzene exposure.
↵‡ WW, wild-type homozygous; WM, wild-type/mutant heterozygous; MM, mutant homozygous.
↵§ P < 0.01.
↵∥ P < 0.05.

Table 3.

Haplotypes/diplotypes of p53 and the odds of chronic benzene poisoning

Haplotype/Diplotypes*	Cases (%)^†	Controls (%)^†	OR (95% CI)	χ²	P
Haplotype
WCC	233 (38.1)	222 (37.6)	1.00
WGC	345 (56.4)	335 (56.8)	0.98 (0.77-1.24)	0.02	0.876
MCA	13 (2.1)	16 (2.7)	0.77 (0.36-1.65)	0.44	0.505
WCA	14 (2.3)	12 (2.0)	1.11 (0.50-2.46)	0.07	0.794
Diplotypes
WCC/WCC	45 (15.1)	44 (15.2)	1.00
WCC/WGC	132 (44.3)	126 (43.5)	1.02 (0.63-1.66)	0.01	0.922
WGC/WGC	95 (31.9)	92 (31.7)	1.01 (0.61-1.67)	0.00	0.970
Other diplotypes^‡	26 (8.7)	28 (9.6)	0.91 (0.46-1.79)	0.08	0.780

Table 4.

Haplotypes/diplotypes of p21 and the odds of chronic benzene poisoning

Haplotype/Diplotypes*	Cases (%)^†	Controls (%)^†	OR (95% CI)	χ²	P
Haplotype
CC	224 (37.2)	184 (31.5)
AT	235 (39.0)	267 (45.7)
AC	131 (21.8)	120 (20.6)
CT	12 (2.0)	13 (2.2)
Diplotypes
CC/CC	60 (19.9)	37 (12.7)	1.00
CC/AT	75 (24.9)	91 (31.2)	0.51 (0.30-0.85)	6.81	0.009
CC/CT	26 (8.6)	15 (5.1)	1.07 (0.50-2.28)	0.30	0.863
AT/AT	39 (13.0)	48 (16.4)	0.50 (0.28-0.90)	5.35	0.021
AT/CT	79 (26.3)	79 (27.1)	0.62 (0.37-1.03)	3.41	0.065
Other diplotypes^‡	22 (7.3)	22 (7.5)	0.62 (0.30-1.27)	1.75	0.186

Table 5.

Demographic characteristics of the study subjects

Variables	Nonexposed	Benzene-exposed	CBP
Number	37	38	39
Age (y)	45.4 ± 5.9*	33.0 ± 7.3	33.4 ± 7.8
Male (%)	15 (34.9)	22 (57.9)	22 (56.4)
Current smoker (%)	14 (32.6)	14 (36.8)	12 (30.8)
Current alcohol user (%)	12 (27.9)	14 (36.8)	19 (48.7)

Table 6.
p53 and p21 mRNA expression (2^-ΔCt × 10³) in the study subjects
Gene Nonexposed (n= 37) Benzene-exposed (n = 38) CBP (n = 39)
p53 16.40 (9.62, 26.83) 2.16 (0.92, 4.03)* 1.61 (0.33, 4.07)*
p21 4.02 (2.39, 5.05) 4.05 (1.79, 7.49) 3.90 (1.32, 8.52)
↵* P < 0.001 (robust multiple regression analysis).