Variations in HSPA1B at 6p21.3 Are Associated with Lung Cancer Risk and Prognosis in Chinese Populations

The heat shock protein Hsp70 is crucial for regulating cellular homeostasis in stressed cells. Although the tumorigenic potential and prognostic applications of Hsp70 have been widely investigated, it remains unclear whether genetic variations of the human isoforms HSPA1L, HSPA1A, and HSPA1B are associated with cancer risk and prognosis. In this study, we genotyped six tagSNPs in these genes in 1,152 paired patients with lung cancer and controls, and then validated the results in additional cohorts of 1,781 patients with lung cancer and 1,038 controls. In addition, we evaluated the associations of these tagSNPs with survival in 330 patients with advanced non-small cell lung cancer (NSCLC) with additional validation in another 331 patients with advanced NSCLC. Functions of the risk variants identified were investigated using cell-based reporter assays. We found that the HSPA1B rs6457452T allele was associated with increased lung cancer risk compared with the rs6457452C allele in both data sets and also pooled analysis (adjusted OR = 1.41; P = 2.8 x 10(-5)). The HSPA1B rs2763979TT genotype conferred poor survival outcomes for patients with advanced NSCLC in two independent cohorts and pooled analysis [adjusted hazard ratio (HR) = 1.80, 1.61, and 1.66; P = 0.013, 0.036, and 0.002, respectively]. Lastly, we also found that the rs2763979T and rs6457452T alleles were each sufficient to reduce expression of transcriptional reporter constructs, when compared with the rs2763979C and rs6457452C alleles, respectively. Taken together, our findings define that functional HSPA1B variants are associated with lung cancer risk and survival. These Hsp70 genetic variants may offer useful biomarkers to predict lung cancer risk and prognosis. Cancer Res; 71(24); 7576-86. (C) 2011 AACR.