Increased steady-state levels of alpha-fetoprotein mRNA in hepatocellular carcinoma: an analysis by in situ hybridization

Association of Common Variants in HNF1A Gene with Serum AFP Level in Healthy Chinese Individuals and HCC Patients

Although alpha-fetoprotein (AFP) is a widely used tumor marker in hepatocellular carcinoma (HCC), 40% of newly diagnosed patients do not have an elevated AFP level. Research has revealed that mutations in the HNF1A binding site of the AFP gene promoter cause significantly elevated serum AFP levels in patients with hereditary persistence of AFP. This study investigated the relationship between HNF1A genetic variants and serum AFP levels. We examined the association between the HNF1A-rs1169288 (A/C), rs2464196 (G/A), and rs1169310 (C/T) polymorphisms and AFP levels in a healthy Chinese population (n = 1010) and HCC patients (n = 185). Single nucleotide polymorphisms were genotyped by the amplification refractory mutation system combined with TaqMan probe in real-time PCR. The serum AFP concentrations were measured using the Architect i2000 immunochemistry analyzer. In healthy individuals, serum AFP levels were significantly lower with the rs2464196-AA and rs1169310-TT genotypes. Similar significant differences were observed in HCC patients. Moreover, in HCC patients, the distribution frequencies of rs2464196-AA+AG and rs1169310-TT+TC among those with AFP ≤ 20 ng/ml or ≤400 ng/ml were significantly lower than those in patients with AFP > 20 ng/ml or >400 ng/ml. Among all subjects, those carrying the HNF1A-rs2464196-A or rs1169310-T allele tended to have low levels of AFP. However, the HNF1A-rs1169288 polymorphism showed no significant association with the serum AFP level. These findings provide new insight into the genetic determinants of serum AFP level and can aid the differential diagnosis of HCC patients with low serum AFP.

A promoter region of the midkine gene that is frequently expressed in human hepatocellular carcinoma can activate a suicide gene as effectively as the alpha-fetoprotein promoter

We examined the expression of the midkine (MK) and alpha-fetoprotein (AFP) genes in 15 paired human specimens obtained from hepatocellular carcinoma (HCC) and the corresponding noncancerous regions of the same patients. A total of 14 HCC but none of the noncancerous specimens were positive for the MK mRNA. In contrast, three HCC specimens and one corresponding noncancerous sample out of the three AFP-positive HCC cases expressed the AFP gene. A 2.3-kb genomic fragment in the regulatory region of the MK gene could activate a fused reporter gene in both AFP-producing and -nonproducing HCC lines, and the MK fragment-mediated transcriptional activity was comparable to the AFP enhancer-linked AFP promoter in AFP-producing cell lines. The AFP-producing but not AFP-nonproducing HCC cell lines that were transfected with the MK promoter-linked herpes simplex virus-thymidine kinase (HSV-TK) gene became susceptible to a prodrug ganciclovir to a similar degree of the HCC transfected with the enhancer-linked AFP promoter-fused HSV-TK gene. These data suggest that the MK promoter can activate a therapeutic gene preferentially in HCC and is as useful as the AFP promoter in clinical settings.