TY - JOUR
T1 - Detection of irradiation-induced, membrane heat shock protein 70 (Hsp70) in mouse tumors using Hsp70 Fab fragment
AU - Stangl, Stefan
AU - Themelis, George
AU - Friedrich, Lars
AU - Ntziachristos, Vasilis
AU - Sarantopoulos, Athanasios
AU - Molls, Michael
AU - Skerra, Arne
AU - Multhoff, Gabriele
N1 - Funding Information:
The study was supported by multimmune GmbH (Munich, Germany), the Deutsche Forschungsgemeinschaft (SFB-824/1; DFG Cluster of Excellence, Munich Center of Advanced Photonics), the Bundesministerium für Bildung und Forschung (BMBF-MOBITUM, 01EZ0826; Kompetenzverbund Strahlenforschung, 03NUK007E; Spitzencluster m4, 01EX1021C; Innovative Therapies, 01GU0823) and the European Union (EU-CARDIORISK, FP7 211403). The authors want to thank Anett Lange for excellent editorial assistance.
PY - 2011/6
Y1 - 2011/6
N2 - Background and purpose: The major stress-inducible heat shock protein 70 (Hsp70) is frequently overexpressed in highly aggressive tumors, and elevated intracellular Hsp70 levels mediate protection against apoptosis. Following therapeutic intervention, such as ionizing irradiation, translocation of cytosolic Hsp70 to the plasma membrane is selectively increased in tumor cells and therefore, membrane Hsp70 might serve as a therapy-inducible, tumor-specific target structure. Materials and methods: Based on the IgG1 mouse monoclonal antibody (mAb) cmHsp70.1, we produced the Hsp70-specific recombinant Fab fragment (Hsp70 Fab), as an imaging tool for the detection of membrane Hsp70 positive tumor cells in vitro and in vivo. Results: The binding characteristics of Hsp70 Fab towards mouse colon (CT26) and pancreatic (1048) carcinoma cells at 4 °C were comparable to that of cmHsp70.1 mAb, as determined by flow cytometry. Following a temperature shift to 37 °C, Hsp70 Fab rapidly translocates into subcellular vesicles of mouse tumor cells. Furthermore, in tumor-bearing mice Cy5.5-conjugated Hsp70 Fab, but not unrelated IN-1 control Fab fragment (IN-1 ctrl Fab), gradually accumulates in CT26 tumors between 12 and 55 h after i.v. injection. Conclusions: In summary, the Hsp70 Fab provides an innovative, low immunogenic tool for imaging of membrane Hsp70 positive tumors, in vivo.
AB - Background and purpose: The major stress-inducible heat shock protein 70 (Hsp70) is frequently overexpressed in highly aggressive tumors, and elevated intracellular Hsp70 levels mediate protection against apoptosis. Following therapeutic intervention, such as ionizing irradiation, translocation of cytosolic Hsp70 to the plasma membrane is selectively increased in tumor cells and therefore, membrane Hsp70 might serve as a therapy-inducible, tumor-specific target structure. Materials and methods: Based on the IgG1 mouse monoclonal antibody (mAb) cmHsp70.1, we produced the Hsp70-specific recombinant Fab fragment (Hsp70 Fab), as an imaging tool for the detection of membrane Hsp70 positive tumor cells in vitro and in vivo. Results: The binding characteristics of Hsp70 Fab towards mouse colon (CT26) and pancreatic (1048) carcinoma cells at 4 °C were comparable to that of cmHsp70.1 mAb, as determined by flow cytometry. Following a temperature shift to 37 °C, Hsp70 Fab rapidly translocates into subcellular vesicles of mouse tumor cells. Furthermore, in tumor-bearing mice Cy5.5-conjugated Hsp70 Fab, but not unrelated IN-1 control Fab fragment (IN-1 ctrl Fab), gradually accumulates in CT26 tumors between 12 and 55 h after i.v. injection. Conclusions: In summary, the Hsp70 Fab provides an innovative, low immunogenic tool for imaging of membrane Hsp70 positive tumors, in vivo.
KW - Binding characteristics
KW - Hsp70 Fab fragment
KW - In vivo imaging
KW - Tumor mouse model
UR - http://www.scopus.com/inward/record.url?scp=79960369894&partnerID=8YFLogxK
U2 - 10.1016/j.radonc.2011.05.051
DO - 10.1016/j.radonc.2011.05.051
M3 - Article
C2 - 21704400
AN - SCOPUS:79960369894
SN - 0167-8140
VL - 99
SP - 313
EP - 316
JO - Radiotherapy and Oncology
JF - Radiotherapy and Oncology
IS - 3
ER -