title: Immunogenicity of 56 degrees C and UVC-treated prostate cancer is associated with release of HSP70 and HMGB1 from necrotic cells.
abstract: BACKGROUND
  Prostate hyperthermia and photodynamic therapy can be delivered by a variety of procedures which result in a wide range of temperatures and light energy and cause different kinds of cell death.
  
  
  METHODS
  We have addressed the immunogenic effect of heating and UVC irradiation on the prostate cancer (PCa) cell line LNCaP, by studying the release of Danger Associated Molecule Pattern (DAMP) molecules HSP70 and HMGB1 and the dendritic cell (DC) antigen-presenting efficiency.
  
  
  RESULTS
  Intracellular upmodulation and extracellular release of HSP70 were inversely correlated. Mild temperatures (43-47 degrees C) induced an early increase of intracellular HSP70, whereas the highest temperature (56 degrees C) induced its extrusion from the cell. Likewise, UVC caused an immediate migration of HSP70 into the cell medium in the absence of any intracellular modulation. 56 degrees C and UVC also induced a robust release of HMGB1. The release of DAMP molecules was closely associated with post-apoptotic membrane damage, as shown by double Annexin V/propidium iodide staining, whereas beta-tubulin, a structural component of cell membranes, was specifically induced by 56 degrees C heating. Tumor uptake strongly impaired the cytokine-driven maturation of DCs and 56 degrees C heating led to a significant recovery of CD83 and CCR7 DC maturation markers, but did not influence the antigen cross-presentation activity. On the contrary, UVC-treated LNCaP had negligible effects on DC maturation, but increased the cross-priming of tumor specific CTL.
  
  
  CONCLUSIONS
  These data may be of use in the design of effective non-surgical PCa ablations that combine tumor destruction with long lasting immunity.
authors.affiliation: Laboratory of Tumor Immunology, Department of Internal Medicine, University of Turin, Turin, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Brusa
authors.forename: Elisa
authors.initials: E
authors.lastname: Migliore
authors.forename: Stefano
authors.initials: S
authors.lastname: Garetto
authors.forename: Mariagrazia
authors.initials: M
authors.lastname: Simone
authors.forename: Lina
authors.initials: L
authors.lastname: Matera
mesh_terms: D017951:Antigen Presentation / Q000276:immunology / Q000528:radiation effects; D014408:Biomarkers, Tumor / Q000378:metabolism; D045744:Cell Line, Tumor; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism / Q000528:radiation effects; D005720:Gamma Rays; D024243:HMGB1 Protein / Q000302:isolation & purification / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D006979:Hyperthermia, Induced; D008297:Male; D009336:Necrosis / Q000276:immunology / Q000378:metabolism / Q000532:radiotherapy; D011471:Prostatic Neoplasms / Q000276:immunology* / Q000532:radiotherapy / Q000628:therapy; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology / Q000276:immunology; D014404:Tubulin / Q000096:biosynthesis; D014466:Ultraviolet Rays
chemical_list: D014408:Biomarkers, Tumor; D024243:HMGB1 Protein; D018840:HSP70 Heat-Shock Proteins; D014404:Tubulin