Hypericin-based photodynamic therapy induces surface exposure of damage-associated molecular patterns like HSP70 and calreticulin
Surface-exposed HSP70 and calreticulin are damage-associated molecular patterns (DAMPs) crucially involved in modulating the success of cancer therapy. Photodynamic therapy (PDT) involves the administration of a photosensitising (PTS) agent followed by visible light-irradiation. The reactive oxygen species that are thus generated directly kill tumours by damaging their microvasculature and inducing a local inflammatory reaction. PDT with the PTS photofrin is associated with DAMPs exposure, but the same is not true for other PTSs. Here, we show that when cancer cells are treated with hypericin-based PDT (Hyp-PDT), they surface-expose both HSP70 and calreticulin (CRT). Induction of CRT exposure was not accompanied by co-exposure of ERp57, but this did not compromise the ability of the exposed CRT to regulate the phagocytosis of Hyp-PDT-treated cancer cells by dendritic cells. Interestingly, we found that Hyp-PDT-induced CRT exposure (in contrast to anthracycline-induced CRT exposure) was independent of the presence of ERp57. Our results indicate that Hyp-PDT is a potential anti-cancer immunogenic modality.
KeywordsCalreticulin HSP70 Photodynamic therapy Hypericin Cancer DAMPs
Damage-associated molecular pattern(s)
Surface externalised-Heat shock protein 70
Heat shock proteins
Hypericin-based photodynamic therapy
We thank Dr. Peter Carmeliet (Vesalius Research Center, VIB, Leuven, Belgium) for the CT26 cells and Dr. Natalio Garbi (German Cancer Research Center, Heidelberg, Germany) for the ERp57 WT and KO MEF cells. This work was supported by a project from the Fund for Scientific Research Flanders (FWO-Vlaanderen, G.0728.10 to P.A. and D.V.K). Research in Agostinis’ group is supported by grants from the K.U.Leuven (GOA/11/009) and FWO-Vlaanderen (G.0661.09). This paper presents research results of the IAP6/18, funded by the Interuniversity Attraction Poles Programme, initiated by the Belgian State, Science Policy Office. D.V.K. is paid by a fellowship from FWO-Vlaanderen. Research in Vandenabeele’s group is supported by VIB and Ghent University (GROUP-ID consortium of the UGent MRP initiative), FWO-Vlaanderen (G.0875.11 and G.0973.11), Federal Research Program (IAP 6/18), European Research Program FP6 ApopTrain (MRTN-CT-035624), FP7 Apo-Sys 200767, and the Euregional PACTII. P.V. holds a Methusalem grant (BOF09/01M00709) from the Flemish Government. We thank Jan Piessens for the technical support. We also thank Dr. Esther Buytaert for her help and contribution to the experiments. We would like to thank Dr. Amin Bredan for excellent editing of the manuscript.
Conflict of interest
The authors declare that they have no conflict of interest.
- 3.Obeid M, Tesniere A, Ghiringhelli F, Fimia GM, Apetoh L, Perfettini JL, Castedo M, Mignot G, Panaretakis T, Casares N, Metivier D, Larochette N, van Endert P, Ciccosanti F, Piacentini M, Zitvogel L, Kroemer G (2007) Calreticulin exposure dictates the immunogenicity of cancer cell death. Nat Med 13(1):54–61. doi: 10.1038/nm1523 PubMedCrossRefGoogle Scholar
- 6.Agostinis P, Berg K, Cengel KA, Foster TH, Girotti AW, Gollnick SO, Hahn SM, Hamblin MR, Juzeniene A, Kessel D, Korbelik M, Moan J, Mroz P, Nowis D, Piette J, Wilson BC, Golab J (2011) Photodynamic therapy of cancer: an update. CA Cancer J Clin 61(4):250–281. doi: 10.3322/caac.20114 PubMedCrossRefGoogle Scholar
- 13.Korbelik M, Zhang W, Merchant S (2011) Involvement of damage-associated molecular patterns in tumor response to photodynamic therapy: surface expression of calreticulin and high-mobility group box-1 release. Cancer Immunol Immunother. doi: 10.1007/s00262-011-1047-x
- 14.Gardai SJ, McPhillips KA, Frasch SC, Janssen WJ, Starefeldt A, Murphy-Ullrich JE, Bratton DL, Oldenborg PA, Michalak M, Henson PM (2005) Cell-surface calreticulin initiates clearance of viable or apoptotic cells through trans-activation of LRP on the phagocyte. Cell 123(2):321–334. doi: 10.1016/j.cell.2005.08.032 PubMedCrossRefGoogle Scholar
- 15.Panaretakis T, Kepp O, Brockmeier U, Tesniere A, Bjorklund AC, Chapman DC, Durchschlag M, Joza N, Pierron G, van Endert P, Yuan J, Zitvogel L, Madeo F, Williams DB, Kroemer G (2009) Mechanisms of pre-apoptotic calreticulin exposure in immunogenic cell death. EMBO J 28(5):578–590. doi: 10.1038/emboj.2009.1 PubMedCrossRefGoogle Scholar
- 16.Buytaert E, Callewaert G, Hendrickx N, Scorrano L, Hartmann D, Missiaen L, Vandenheede JR, Heirman I, Grooten J, Agostinis P (2006) Role of endoplasmic reticulum depletion and multidomain proapoptotic BAX and BAK proteins in shaping cell death after hypericin-mediated photodynamic therapy. FASEB J 20(6):756–758. doi: 10.1096/fj.05-4305fje PubMedGoogle Scholar
- 17.Vantieghem A, Assefa Z, Vandenabeele P, Declercq W, Courtois S, Vandenheede JR, Merlevede W, de Witte P, Agostinis P (1998) Hypericin-induced photosensitization of HeLa cells leads to apoptosis or necrosis. Involvement of cytochrome c and procaspase-3 activation in the mechanism of apoptosis. FEBS Lett 440(1–2):19–24. doi: S0014-5793(98)01416-1 PubMedCrossRefGoogle Scholar
- 20.Panaretakis T, Joza N, Modjtahedi N, Tesniere A, Vitale I, Durchschlag M, Fimia GM, Kepp O, Piacentini M, Froehlich KU, van Endert P, Zitvogel L, Madeo F, Kroemer G (2008) The co-translocation of ERp57 and calreticulin determines the immunogenicity of cell death. Cell Death Differ 15(9):1499–1509. doi: 10.1038/cdd.2008.67 PubMedCrossRefGoogle Scholar