Variations of serum alpha fetoprotein afp levels in hepatocellular carcinoma patients and cell lines are likely due to the differential activity of enhancer/silencer elements that control AFP. To understand the potential mechanism underlying the differential expression of AFP, we have examined the sequence of the AFP promoter in HCC.
Three novel SNPs in the promoter region of the AFP gene , which have not been previously reported, were found at positions −330, −401 and −692. The level of serum alpha fetoprotein was significantly higher in HCC patients with the CT genotype of 330 SNP or the AG genotype of the 401 SNP. The genotype of CG in 692 SNP was also associated with a significant elevated level of serum alpha fetoprotein , and further this genotype appeared to be associated with the high risk of HCC development. 401 SNP and 692 SNP were located at the positions of known binding sites for transcription factors that have a role in the production of alpha fetoprotein and the growth of tumors .
The novel polymorphisms identified in the promoter region of the AFP gene may be pathologically significant in HCC.
Department of Surgery, The Chinese University of Hong Kong , Prince of Wales Hospital, Shatin, New Territories, Hong Kong