Expression of heat shock proteins in human hepatocellular carcinoma after radiofrequency ablation in an animal model.
Since tumor cells are known to express heat shock proteins (HSPs) as a response to cellular stress, such as heat, our goal was to determine the expression of HSPs in human hepatocellular carcinoma (HCC) before and after percutaneous radiofrequency (RF) ablation using a rat model. In 12 nude rats, human HCC cells (SK-HEP-1) were inoculated subcutaneously. A total of 21 tumors were grown in the bilateral flanks of the rats. Of those, 19 were treated with percutaneous RF ablation (diameter of RF electrode, 18 gauge; RF ablation energy, 60-600 W; duration, 20-100 sec). To determine the extent of necrosis, and the cellular expression of HSP 70 and HSP 90, the tumors were excised within 6, 12 and 24 h after RF ablation, respectively. The extent of the coagulation necrosis and the expression of HSP 70 and 90 were evaluated. Linear regression analysis showed a significant correlation between the volume of coagulation necrosis and the RF energy applied. Before RF ablation, expression of HSP 70 and 90 was 0% and 0-30%, respectively. Following RF ablation, the maximum level of HSP 70 expression was 60%, and the maximum level of HSP 90 expression was 100%. The expression of HSP 70 and 90 in HCC is significantly increased by RF ablation. These findings are of particular importance in the host-tumor immune response and might be useful in forthcoming immunotherapeutical strategies.
Department of Radiology, University Hospital Vienna, Waehringer Guertel 18-20/7F, A-1090 Vienna, Austria. gerd.schueller@univie.ac.at
Gerd
G
Schueller
Joachim
J
Kettenbach
Roland
R
Sedivy
Helga
H
Bergmeister
Anton
A
Stift
Josef
J
Fried
Michael
M
Gnant
Johannes
J
Lammer
D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000628:therapy*; D017115:Catheter Ablation; D045744:Cell Line, Tumor; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D007167:Immunotherapy / Q000379:methods; D016014:Linear Models; D008113:Liver Neoplasms / Q000378:metabolism* / Q000628:therapy*; D009336:Necrosis; D009368:Neoplasm Transplantation; D051381:Rats; D011923:Rats, Nude; D013997:Time Factors
D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D006360:Heat-Shock Proteins