Polymorphisms in heat-shock protein 70 genes are associated with coal workers' pneumoconiosis in southwestern China.

BACKGROUND Heat-shock proteins (HSPs) protect cells and tissues against different types of damage. This study investigated the relationship between the genetic variation in constitutive and inducible HSP70 genes and the risk for coal workers' pneumoconiosis (CWP) among miners in southwestern China. PATIENTS AND METHODS A job exposure matrix (JEM) was used to estimate the dust exposure level of individuals. A total of 225 CWP patients and 294 healthy individuals were assessed by genotyping for the single-nucleotide polymorphisms (SNPs) of the HSP70-1 (190 G/C), HSP70-2 (1267 A/G), and HSP70-hom (2437 T/C) genes. The association between these polymorphisms and the risk for CWP was assessed. RESULTS Polymerase chain reaction-restriction fragment length polymorphism analysis revealed no statistically significant differences between the dust exposure level and the polymorphisms of HSP70-1, HSP70-2 and HSP70-hom in individuals. However, there were significant differences in the distribution of the G allele for HSP70-2 among the different categories of CWP and in the genotype frequency for HSP70-hom between CWP patients and controls. Furthermore, five HSP haplotypes of the HSP70 genes (namely GAT, GAC, GGT, CAC and CGT) were examined and the frequencies of haplotypes GAT and GGT were significantly higher in the CWP than in the control group. CONCLUSION The genotyping results of this study indicate that the G allele distribution of HSP70-2, the genotype frequency of HSP70-hom poly-morphisms and some haplotypes of the HSP70 genes are associated with the susceptibility to and severity of CWP, and may be involved in the pathogenesis and development of CWP in the southwestern Chinese Han population.