Quantitation of alpha-fetoprotein messenger RNA for early detection of recurrent hepatocellular carcinoma: A prospective pilot study

AFP mRNA level in enriched circulating tumor cells from hepatocellular carcinoma patient blood samples is a pivotal predictive marker for metastasis

Circulating tumor cells (CTCs) quantification may be helpful for evaluating cancer dissemination, predicting prognosis and assessing therapeutic effectiveness and safety. In the present study, CTCs from blood samples of 72 patients with hepatocellular carcinoma (HCC) were enriched with anti-EpCAM nanoparticles. AFP mRNA level was detected by nested polymerase chain reaction (PCR) after enrichment of CTCs from HCC blood samples at 0, 3, 6, 9 and 12 months after hepatectomy, respectively. AFP mRNA expression in CTCs was positive in 43 patients (59.7%) and negative in 29 patients (40.3%) before hepatectomy. Among 43 patients with positive AFP mRNA expression in CTCs before hepatectomy, 10 and 11 were diagnosed as intrahepatic/extrahepatic metastasis before and after hepatectomy, respectively. In addition, these 21 patients with metastasis had persisting positive AFP mRNA of CTCs during the whole tested year. Specifically, 3 patients with AFP mRNA negative in CTCs before hepatectomy changed to be positive at 6 and 9 months, and 2 of them were diagnosed as metastasis 12 months after hepatectomy. We conclude that the positive AFP mRNA of CTCs can be a pivotal predictor for HCC metastasis before and after hepatectomy. The release of AFP expression from hepatocellular carcinoma cells into circulation must be a major source of HCC metastasis.

Novel alpha-fetoprotein-V messenger RNA isoforms in humans

It has been demonstrated that several messenger RNA (mRNA) isoforms have been transcribed from the alpha-fetoprotein (AFP) gene. In rats, it was reported that the novel exon, termed the exon V, exists between the exons 7 and 8, and the novel mRNA isoform (termed AFP-V mRNA) is synthesized using the exon V. In this study, a reverse transcription-polymerase chain reaction was performed and quantitative analysis was done on the AFP mRNA to identify the exon V and the AFP-V mRNA in humans. As a result, 2 novel exons, the exons VA and VB, were identified. Furthermore, 3 novel AFP mRNAs, the AFP-V1, -V2, and -V3 mRNA, were demonstrated to be expressed through alternative splicing. Expression of the AFP-V2 mRNA isoform and the wild-type mRNA was differentially regulated, implying that the AFP-V mRNA isoforms could be used in diagnosis and classification of hepatocellular carcinoma and ovarian carcinoma.