title: Tumor-specific immunity induced by cryoablation in a murine renal cell carcinoma model.
abstract: OBJECTIVE
  To evaluate tumor-specific immunity and define the mechanisms involved in the cryoimmunologic response, we compared the tumor control efficacy and immunologic responses of cryoablation with those of surgical excision in a tumor rechallenge model.
  
  
  METHODS
  Sixty BALB/c mice with RENCA tumors that were generated in the left flank area underwent cryoablation or radical excision. The mice successfully treated were rechallenged with RENCA or an undifferentiated colon carcinoma cell line, CT26, in the contralateral right flank area. The recurrence rate after tumor rechallenge in each group was then observed. To assess the immunologic response of each treatment modality, fluorescent-activated cell sorting (FACS) analysis and a cytotoxicity assay using (51)Cr release were performed.
  
  
  RESULTS
  After reinoculation of the RENCA cells, the rate of tumor growth was significantly higher in the surgical excision group than in the cryoablation group (94.4% vs. 11.1%, p=0.001). In the cryoablation group, the tumor growth rate was significantly increased after rechallenge of CT26 cells compared with RENCA (94.1% vs. 11.1%, p=0.001). The cryoablation group showed an elevated CD3, CD4, CD8 T, and natural killer cell count in the FACS analysis and also showed significantly increased cytotoxicity in the (51)Cr release assay compared with the excision group.
  
  
  CONCLUSIONS
  These results showed that cryoablation, compared to surgical resection, was more effective in preventing tumor growth after rechallenge with RENCA cells and that this response was tumor-specific, because the CT26 cells did not have the same effect.
authors.affiliation: Department of Urology, Korea University Anam Hospital, Seoul, Korea.
authors.forename: Hyung Keun
authors.initials: HK
authors.lastname: Kim
authors.affiliation: Department of Urology, Korea University Anam Hospital, Seoul, Korea.
authors.forename: Jong Hyun
authors.initials: JH
authors.lastname: Pyun
authors.affiliation: Department of Urology, Korea University Anam Hospital, Seoul, Korea.
authors.forename: Seok
authors.initials: S
authors.lastname: Cho
authors.affiliation: Department of Urology, Korea University Anam Hospital, Seoul, Korea.
authors.forename: Sung Gu
authors.initials: SG
authors.lastname: Kang
authors.affiliation: Department of Urology, Korea University Anam Hospital, Seoul, Korea.
authors.forename: Jeong Gu
authors.initials: JG
authors.lastname: Lee
authors.affiliation: Department of Urology, Korea University Anam Hospital, Seoul, Korea.
authors.forename: Je Jong
authors.initials: JJ
authors.lastname: Kim
authors.affiliation: Department of Urology, Korea University Anam Hospital, Seoul, Korea.
authors.forename: Jun
authors.initials: J
authors.lastname: Cheon
authors.affiliation: Department of Urology, Korea University Guro Hospital, Seoul, Korea.
authors.forename: Hong Seok
authors.initials: HS
authors.lastname: Park
authors.affiliation: Department of Urology, Korea University Anam Hospital, Seoul, Korea.
authors.forename: Seok Ho
authors.initials: SH
authors.lastname: Kang
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002292:Carcinoma, Renal Cell / Q000276:immunology* / Q000473:pathology / Q000601:surgery*; D016923:Cell Death; D003452:Cryosurgery / Q000379:methods*; D003602:Cytotoxicity, Immunologic; D004195:Disease Models, Animal; D007680:Kidney Neoplasms / Q000276:immunology* / Q000473:pathology / Q000601:surgery*; D018655:Lymphocyte Count; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology; D008807:Mice, Inbred BALB C; D009364:Neoplasm Recurrence, Local / Q000276:immunology; D009368:Neoplasm Transplantation
keywords: Animal models; Cryosurgery; Immunity; Renal cell carcinoma