TY - JOUR
T1 - Radiolabeled human monoclonal antibody 067-213 has the potential for noninvasive quantification of cd73 expression
AU - Sudo, Hitomi
AU - Tsuji, Atsushi B.
AU - Sugyo, Aya
AU - Kurosawa, Gene
AU - Kurosawa, Yoshikazu
AU - Alexander, David
AU - Tsuda, Hiroyuki
AU - Saga, Tsuneo
AU - Higashi, Tatsuya
N1 - Funding Information:
Funding: This work was in part supported by KAKENHI (18K07778, 18H02774, 17K10497) and the Princess Takamatsu Cancer Research Fund (17-24907).
PY - 2020/4/1
Y1 - 2020/4/1
N2 - Background: CD73 is an ectonucleotidase regulating extracellular adenosine concentration and plays an important role in adenosine-mediated immunosuppressive pathways. The efficacy of CD73-targeted therapy depends on the expression levels of CD73; therefore, monitoring CD73 status in cancer patients would provide helpful information for selection of patients who would benefit from CD73-targeted therapy. Here, we evaluated the ability of111 In-labeled antibody 067-213, which has high affinity for human CD73, to act as a noninvasive imaging probe. Methods: Cell binding and competitive inhibition assays for111 In-labeled 067-213 were conducted using MIAPaCa-2 (high CD73 expression) and A431 (low CD73 expression) cells. For in vivo assessments, biodistribution and SPECT/CT studies were conducted in MIAPaCa-2 and A431 tumor-bearing mice. To estimate the absorbed dose in humans, biodistribution and SPECT/CT studies were conducted in healthy rats. Results:111 In-labeled 067-213 bound to MIAPaCa-2 and A431 cells in a CD73-dependent manner and the affinity loss after111In-labeling was limited. Biodistribution and SPECT/CT studies with111 In-labeled 067-213 in mice showed high uptake in MIAPaCa-2 tumors and lower uptake in A431 tumors. In rats, the probe did not show high uptake in normal organs, including endogenously CD73-expressing organs. The estimated absorbed doses in humans were reasonably low. Conclusions:111 In-labeled 067-213 showed CD73-expression-dependent tumor uptake and low uptake in normal organs and tissues. Radiolabeled 067-213 holds promise as an imaging probe for noninvasive evaluation of CD73 expression levels in patients. Our data encourage further clinical studies to clarify a role for CD73 monitoring in patients receiving CD73-targeted immune therapy.
AB - Background: CD73 is an ectonucleotidase regulating extracellular adenosine concentration and plays an important role in adenosine-mediated immunosuppressive pathways. The efficacy of CD73-targeted therapy depends on the expression levels of CD73; therefore, monitoring CD73 status in cancer patients would provide helpful information for selection of patients who would benefit from CD73-targeted therapy. Here, we evaluated the ability of111 In-labeled antibody 067-213, which has high affinity for human CD73, to act as a noninvasive imaging probe. Methods: Cell binding and competitive inhibition assays for111 In-labeled 067-213 were conducted using MIAPaCa-2 (high CD73 expression) and A431 (low CD73 expression) cells. For in vivo assessments, biodistribution and SPECT/CT studies were conducted in MIAPaCa-2 and A431 tumor-bearing mice. To estimate the absorbed dose in humans, biodistribution and SPECT/CT studies were conducted in healthy rats. Results:111 In-labeled 067-213 bound to MIAPaCa-2 and A431 cells in a CD73-dependent manner and the affinity loss after111In-labeling was limited. Biodistribution and SPECT/CT studies with111 In-labeled 067-213 in mice showed high uptake in MIAPaCa-2 tumors and lower uptake in A431 tumors. In rats, the probe did not show high uptake in normal organs, including endogenously CD73-expressing organs. The estimated absorbed doses in humans were reasonably low. Conclusions:111 In-labeled 067-213 showed CD73-expression-dependent tumor uptake and low uptake in normal organs and tissues. Radiolabeled 067-213 holds promise as an imaging probe for noninvasive evaluation of CD73 expression levels in patients. Our data encourage further clinical studies to clarify a role for CD73 monitoring in patients receiving CD73-targeted immune therapy.
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U2 - 10.3390/ijms21072304
DO - 10.3390/ijms21072304
M3 - Article
C2 - 32225110
AN - SCOPUS:85082732964
VL - 21
JO - International Journal of Molecular Sciences
JF - International Journal of Molecular Sciences
SN - 1661-6596
IS - 7
M1 - 2304
ER -