Noninvasive detection of breast cancer lymph node metastasis using carbonic anhydrases IX and XII targeted imaging probes.
OBJECTIVE
To develop targeted molecular imaging probes for the noninvasive detection of breast cancer lymph node metastasis.


METHODS
Six cell surface or secreted markers were identified by expression profiling and from the literature as being highly expressed in breast cancer lymph node metastases. Two of these markers were cell surface carbonic anhydrase isozymes (CAIX and/or CAXII) and were validated for protein expression by immunohistochemistry of patient tissue samples on a breast cancer tissue microarray containing 47 normal breast tissue samples, 42 ductal carcinoma in situ, 43 invasive ductal carcinomas without metastasis, 46 invasive ductal carcinomas with metastasis, and 49 lymph node macrometastases of breast carcinoma. Targeted probes were developed by conjugation of CAIX- and CAXII-specific monoclonal antibodies to a near-infrared fluorescent dye.


RESULTS
Together, these two markers were expressed in 100% of the lymph node metastases surveyed. Selectivity of the imaging probes were confirmed by intravenous injection into nude mice-bearing mammary fat pad tumors of marker-expressing cells and nonexpressing cells or by preinjection of unlabeled antibody. Imaging of lymph node metastases showed that peritumorally injected probes detected nodes harboring metastatic tumor cells. As few as 1,000 cells were detected, as determined by implanting, under ultrasound guidance, a range in number of CAIX- and CAXII-expressing cells into the axillary lymph nodes.


CONCLUSIONS
These imaging probes have potential for noninvasive staging of breast cancer in the clinic and elimination of unneeded surgery, which is costly and associated with morbidities.
Department of Molecular & Functional Imaging, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA.
Narges K
NK
Tafreshi
Marilyn M
MM
Bui
Kellsey
K
Bishop
Mark C
MC
Lloyd
Steven A
SA
Enkemann
Alexis S
AS
Lopez
Dominique
D
Abrahams
Bradford W
BW
Carter
Josef
J
Vagner
Stephen R
SR
Grobmyer
Stephen R
SR
Gobmyer
Robert J
RJ
Gillies
David L
DL
Morse
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000493:pharmacokinetics; D000951:Antigens, Neoplasm / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D001940:Breast / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000276:immunology / Q000378:metabolism; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases / Q000378:metabolism*; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis* / Q000276:immunology / Q000378:metabolism; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000175:diagnosis* / Q000276:immunology / Q000378:metabolism; D003952:Diagnostic Imaging; D005260:Female; D005455:Fluorescent Antibody Technique; D020869:Gene Expression Profiling; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D008163:Luminescent Measurements; D008207:Lymphatic Metastasis; D051379:Mice; D008819:Mice, Nude; D009361:Neoplasm Invasiveness; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D046888:Tissue Array Analysis; D014018:Tissue Distribution; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D012333:RNA, Messenger; D008156:Luciferases; C089226:CA9 protein, human; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases; C477378:carbonic anhydrase XII