Heterogeneous expression of A33 in colorectal cancer: possible explanation for A33 antibody treatment failure.
The A33 protein, expressed in colorectal tumors, is a target for improving treatment of patients with colorectal cancer. Over the last decade, studies have tested anti-A33 antibody as a therapeutic agent for these patients. Preclinical results were promising, but clinical trials did not confirm positive results. Here, immunohistochemistry in colorectal cancer tissue showed that samples from well-differentiated tumors presented a strong A33 membrane staining, whereas poorly differentiated tumors and mucinous adenocarcinomas showed weak cytoplasmic and nuclear staining. Moderately differentiated tumors presented variable staining. We suggest that in future clinical trials, patients should be selected on the basis of membrane expression of A33.
aInternational Research Center Departments of bPelvic Surgery cAnatomic Pathology, AC Camargo Cancer Center dNational Institute for Science and Technology on Oncogenomics - INCITO (CNPq/MCT/FAPESP), São Paulo, Brazil.
Antuani R
AR
Baptistella
Marcos Vinicios
MV
Salles Dias
Samuel
S
Aguiar
Maria D
MD
Begnami
Vilma R
VR
Martins
D000911:Antibodies, Monoclonal / Q000627:therapeutic use; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D006801:Humans; D008562:Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism*; D017211:Treatment Failure
D000911:Antibodies, Monoclonal; C104258:GPA33 protein, human; D008562:Membrane Glycoproteins