Interactive Effect of Bisphenol A (BPA) Exposure with -22G/C Polymorphism in LOX Gene on the Risk of Osteosarcoma

BACKGROUND: Osteosarcomas have many established risk factors, both genetic and environmental, but by themselves these explain only part of the total cancer incidence. Bisphenol A (BPA) is an environmental estrogen associated with risk of several kinds of tumour. The lysyl oxidase gene (LOX) may also contribute to risk of tumours including osteosarcomas. Here, we investigated possible interactions of BPA and a LOX polymorphism on the risk of osteosarcoma. METHOD: The present hospital-based case-control study included 106 cancer patients and 112 controls from a Chinese population. Internal burden of BPA exposure was assessed using high-performance liquid chromatography-mass spectrometry (HPLC-MS) method. Genotypes were determined using PCR-RFLP methods. RESULTS: Compared with those in low BPA exposure group, subjects with BPA more than or equal to median value had significant increased risk of osteosarcoma among subjects who carried GC or CC genotypes. A significant interaction with BPA level and the -22 G/C polymorphism was observed for osteosarcoma overall, osteosarcoma affecting knee and osteosarcoma affecting hip, as P(forinteraction) = 0.036 for osteosarcoma overall; P(forinteraction) = 0.024 for osteosarcoma affecting knee; and P(forinteraction) = 0.017 for osteosarcoma affecting hip. CONCLUSIONS: The results suggest that BPA exposure interacts with the -22 G/C polymorphism of the LOX gene to increase the risk of osteosarcoma.