TY - JOUR
T1 - Cell death triggered by alpha-emitting 213Bi-immunoconjugates in HSC45-M2 gastric cancer cells is different from apoptotic cell death
AU - Seidl, Christof
AU - Schröck, Hedwig
AU - Seidenschwang, Sabine
AU - Beck, Roswitha
AU - Schmid, Ernst
AU - Abend, Michael
AU - Becker, Karl Friedrich
AU - Apostolidis, Christos
AU - Nikula, Tuomo K.
AU - Kremmer, Elisabeth
AU - Schwaiger, Markus
AU - Senekowitsch-Schmidtke, Reingard
N1 - Funding Information:
Acknowledgements. We would like to thank Ralf Bogumil (Cipher-gen Biosystems) for conducting the SELDI-TOF mass spectrometric analyses. We also thank Martin W. Brechbiel (NIH, USA) for providing SCN-CHX-A″-DTPA chelate and Kazuyoshi Yanagihara (National Cancer Center Research Institute, Tokyo, Japan) for providing the HSC45-M2 stomach cancer cell line. We are grateful to Ramon Carlos-Marquez and Roger Molinet (Institute for Transuranium Elements, Karlsruhe, Germany) for the preparation of the 225Ac/213Bi generator systems. The work was supported by grant SE 962/2 of the Deutsche Forschungsgemeinschaft.
PY - 2005/3
Y1 - 2005/3
N2 - Purpose: Radioimmunotherapy with α-particle-emitting nuclides, such as 213Bi, is a promising concept for the elimination of small tumour nodules or single disseminated tumour cells. The aim of this study was to investigate cellular damage and the mode of cell death triggered by 213Bi-immunoconjugates. Methods: Human gastric cancer cells (HSC45-M2) expressing d9-E-cadherin were incubated with different levels of activity of 213Bi-d9MAb targeting d9-E-cadherin and 213Bi-d8MAb, which does not bind to d9-E-cadherin. Micronucleated (M) cells, abnormal (A) cells and apoptotic (A) [(MAA)] cells were scored microscopically in the MAA assay following fluorescent staining of nuclei and cytoplasm. Chromosomal aberrations were analysed microscopically following Giemsa staining. The effect of z-VAD-fmk, known to inhibit apoptosis, on the prevention of cell death was investigated following treatment of HSC45-M2 cells with sorbitol as well as 213Bi-d9MAb. Activation of caspase 3 after incubation of HSC45-M2 cells with both sorbitol and 213Bi-d9MAb was analysed via Western blotting. Results: Following incubation of HSC45-M2 human gastric cancer cells expressing d9-E-cadherin with 213Bi-d9MAb the number of cells killed increased proportional to the applied activity concentration. Microscopically visible effects of α-irradiation of HSC45-M2 cells were formation of micronuclei and severe chromosomal aberrations. Preferential induction of these lesions with specific 213Bi-d9MAb compared with unspecific 213Bi-d8MAb (not targeting d9-E-cadherin) was not observed if the number of floating, i.e. unbound 213Bi- immunoconjugates per cell exceeded 2×104, most likely due to intense crossfire. In contrast to sorbitol-induced cell death, cell death triggered by 213Bi-immunoconjugates was independent of caspase 3 activation and could not be inhibited by z-VAD-fmk, known to suppress the apoptotic pathway. Conclusion: 213Bi-immunoconjugates seem to induce a mode of cell death different from apoptosis in HSC45-M2 cells.
AB - Purpose: Radioimmunotherapy with α-particle-emitting nuclides, such as 213Bi, is a promising concept for the elimination of small tumour nodules or single disseminated tumour cells. The aim of this study was to investigate cellular damage and the mode of cell death triggered by 213Bi-immunoconjugates. Methods: Human gastric cancer cells (HSC45-M2) expressing d9-E-cadherin were incubated with different levels of activity of 213Bi-d9MAb targeting d9-E-cadherin and 213Bi-d8MAb, which does not bind to d9-E-cadherin. Micronucleated (M) cells, abnormal (A) cells and apoptotic (A) [(MAA)] cells were scored microscopically in the MAA assay following fluorescent staining of nuclei and cytoplasm. Chromosomal aberrations were analysed microscopically following Giemsa staining. The effect of z-VAD-fmk, known to inhibit apoptosis, on the prevention of cell death was investigated following treatment of HSC45-M2 cells with sorbitol as well as 213Bi-d9MAb. Activation of caspase 3 after incubation of HSC45-M2 cells with both sorbitol and 213Bi-d9MAb was analysed via Western blotting. Results: Following incubation of HSC45-M2 human gastric cancer cells expressing d9-E-cadherin with 213Bi-d9MAb the number of cells killed increased proportional to the applied activity concentration. Microscopically visible effects of α-irradiation of HSC45-M2 cells were formation of micronuclei and severe chromosomal aberrations. Preferential induction of these lesions with specific 213Bi-d9MAb compared with unspecific 213Bi-d8MAb (not targeting d9-E-cadherin) was not observed if the number of floating, i.e. unbound 213Bi- immunoconjugates per cell exceeded 2×104, most likely due to intense crossfire. In contrast to sorbitol-induced cell death, cell death triggered by 213Bi-immunoconjugates was independent of caspase 3 activation and could not be inhibited by z-VAD-fmk, known to suppress the apoptotic pathway. Conclusion: 213Bi-immunoconjugates seem to induce a mode of cell death different from apoptosis in HSC45-M2 cells.
KW - Alpha-emitter Bi
KW - Caspase 3 activation
KW - Chromosomal aberrations
KW - MAA assay
KW - Tumour-specific antibody
UR - http://www.scopus.com/inward/record.url?scp=20244384731&partnerID=8YFLogxK
U2 - 10.1007/s00259-004-1653-3
DO - 10.1007/s00259-004-1653-3
M3 - Article
C2 - 15791436
AN - SCOPUS:20244384731
SN - 1619-7070
VL - 32
SP - 274
EP - 285
JO - European Journal of Nuclear Medicine and Molecular Imaging
JF - European Journal of Nuclear Medicine and Molecular Imaging
IS - 3
ER -
