Expression of alpha fetoprotein messenger RNA in BEL-7404 human hepatoma cells and effect of L-4-oxalysine on the expression

Detecting carcinoma cells in peripheral blood of patients with hepatocellular carcinoma by immunomagnetic beads and rt-PCR

BACKGROUND

Increasing the sensitivity and specificity of detecting circulating carcinoma cells of patients with hepatocellular carcinoma (HCC) is very important for monitoring recurrence.

GOAL

To establish a novel method of detecting circulating carcinoma cells.

STUDY

For method development, 3 sets of controls using HCC cell line HepG2 cells were used. (A): Serial dilutions of HepG2 cells were directly used to extract total RNA for nested reverse transcription-polymerase chain reaction (RT-PCR). (B): Five milliliter of healthy blood was spiked with a serial dilution of HepG2 cells and was used for Ficoll density gradient centrifugation to recover cells. The cells were used to extract total RNA for RT-PCR. (C): After cell recovery with the same procedure as B, the cells were sorted sequentially by CD45 and Ber-EP4 immunomagnetic beads and used for RNA extraction and RT-PCR. For clinical samples, 44 patients with HCC and 7 healthy subjects were included. The alpha-fetoprotein mRNA was amplified using nested RT-PCR technique.

RESULTS

The spiking experiments using HepG2 cells showed that 10 cells in 5 mL blood could be detected by method C and an excellent dose-response to the number of spiked cells. Whereas, method B lacked any dose-response and would yield high false-positive rates. In clinical samples, the improved method led to a positive detection rate of 52.9%, 76.9%, and 92.9% in Child-Plug class A, B, and C, respectively. There was significant difference between class A and class C (P<0.05). The total positive detection rate was 72.7%.

CONCLUSIONS

Combining negative and positive immunomagnetic beads with RT-PCR technique may improve the sensitivity and specificity of detecting circulating HCC cells.

Antihepatoma effect of alpha-fetoprotein antisense phosphorothioate oligodeoxyribonucleotides in vitro and in mice

AIM: To evaluate antihepatoma effect of antisense phosphorothioate oligodeoxyribonucleotides (S-ODNs) targeted to alpha-fetoprotein (AFP) genes in vitro and in nude mice.

METHODS: AFP gene expression was examined by immunocytochemical method or enzyme-linked immunosorbent assay. Effect of S-ODNs on SMMC-7721 human hepatoma cell growth in vitro was determined using microculture tetrazolium assay. In vivo antitumor activities of S-ODNs were monitored by measuring tumor weight differences in treated and control mice bearing SMMC-7721 xenografts. Induction of cell apoptosis was evaluated by fluorescence-activated cell sorter (FACS) analysis.

RESULTS: Antisense S-ODN treatment led to reduced AFP gene expression. Specific antisense S-ODNs, but not control S-ODNs, inhibited the growth of heaptoma cells in vitro. In vivo, only antisense S-ODNs exhibited obvious antitumor activities. FACS analysis revealed that the growth inhibition by antisense S-ODNs was associated with their cell apoptosis induction.

CONCLUSION: Antisense S-ODNs targeted to AFP genes inhibit the growth of human hepatoma cells and solid hepatoma, which is related to their cell apoptosis induction.