The effect of radiofrequency ablation with sublethal temperature on the stem cells of hepatocellular carcinoma / 介入放射学杂志

ABSTRACT

Objective To study the effect of radiofrequency ablation (RFA) with sublethal temperature on the production of liver cancer stem cells (LCSCs) and on the expression of LCSCs-related transcriptional factors.Methods Mouse hepl-6 hepatoma cell line and clinical samples of patients with hepatocellular carcinoma (HCC) were used to test the expressions of LCSCs-related markers and transcriptional factors.Results Different temperatures were used to stimulate Hep1-6 cells,and it was proved that the temperature of 45℃ was a sublethal temperature that could not induce cell death.Flow cytometry testing showed that treatment with 45℃ could obviously increase CD13+,CD44+,CD90 and CD133+ Hep1-6 cells,suggesting that treatment with 45℃ could increase the production of above mentioned types of LCSCs in hep1-6 cells.Real-time quantitative polymerase chain reaction (RT-qPCR) assay indicated that the temperature of 45℃could cause significant increase in CD13,CD90 and CD133 mRNA.In all 5 HCC patients,CD13 mRNA in the recurrent HCC lesions was remarkably increased,CD133 mRNA was increased in 4 patients with recurrent HCC,and CD90 mRNA was increased in only one patient with recurrent HCC.Flow cytometry testing revealed that CD13+ LCSCs were strikingly increased in 4 recurrent HCC patients,while CD133+LCSC was increased in only one patient,suggesting that more close correlation existed between the increase of CD13+ LCSCs and the temperature of 45℃.RT-qPCR assay showed that in 4 recurrent HCC patients with increased CD13+ LCSC,the Sox2 and Stat2 among 13 LCSCs-related transcriptional factors were obviously increased.Flow cytometry testing showed that 45℃ treatment also increased the expression of Sox2 and Stat1 mRNA in Hep1-6 cells.Finally,Sox2 and Stat1 could be knockdown by siRNAs,indicating that both Sox2 and Stat1 transcriptional factors were involved in 45℃-induced production of CD13+ LCSCs in Hep1-6 cells.Conclusion In RFA therapy,the use of sublethal temperature of 45℃ can increase CD13+LCSCs,which is related to the promotion of Sox2 and Stat1 expression.The results of this study can be used for reference in the research of liver cancer recurrence.