Risk of nasopharyngeal carcinoma associated with polymorphic lactotransferrin haplotypes

Lactotransferrin (LTF) is a component of the nonspecific immune system, having antimicrobial properties against bacteria, fungi, and several viruses. The gene coding for LTF is polymorphic, with the occurrence of several common alleles in the general population. Our previous study found that LTF inhibited nasopharyngeal carcinoma (NPC) cell proliferation in vitro and in vivo. To better understand one possible mechanism of LTF-mediated antitumor activity in NPC cells, in the present study, we investigated the distribution of LTF gene polymorphisms (rs1126477, rs1126478, rs2073495, and rs9110) in NPC and revealed whether these polymorphisms were associated with LTF gene expression. It was found that rs2073495 and rs9110 were correlated significantly with NPC. The frequency of CC genotype was higher and GG or TT genotype was lower, in NPC patients compared with that in the control group (P < 0.05, χ(2) = 8.73 and 9.33, respectively). CC genotype is the risk factor for NPC. Haplotype analyses indicated that NPC patients had lower rate of 'A-G-G-T' haplotype (constructed with rs1126477, rs1126478, rs2073495, and rs9110) compared with controls (P = 4.12 × 10(-6) < 0.001, χ(2) = 21.25). The population with 'A-G-G-T' haplotype had 0.322-fold risk to be NPC. The expression of LTF gene was high in NPC tissues and control tissues with 'A-G-G-T' haplotype compared with these without its. These findings suggested that rs2073495 and rs9110 could play important roles in NPC physiological processes.