Background: The Activated Leukocyte Cell Adhesion Mol. (ALCAM/CD166), involved in nervous system development, has been linked to tumor progression and metastasis in several tumors. No information is available on ALCAM expression in neuroblastoma, a childhood neoplasia originating from the sympathetic nervous system. Methods: ALCAM expression was analyzed by immunofluorescence and immunohistochem. on differentiated neuroblastoma cell lines and on archival specimens of stroma-poor, not MYCN amplified, resectable neuroblastoma tumors, resp. Results: ALCAM is variously expressed in neuroblastoma cell lines, is shed by metalloproteases and is cleaved by ADAM17/TACE in vitro. ALCAM is expressed in neuroblastoma primary tumors with diverse patterns of subcellular localization and is highly expressed in the neuropil area in a subgroup of cases. Tumor specimens showing high expression of ALCAM at the membrane of the neuroblast body or low levels in the neuropil area are assocd. with relapse (P=0.044 and P<0.0001, resp.). In vitro differentiated neuroblastoma cells show strong ALCAM expression on neurites, suggesting that ALCAM expression in the neuropil is related to a differentiated phenotype. Conclusion: Assessment of ALCAM localization by immunohistochem. may help to identify patients who, in the absence of neg. prognostic factors, are at risk of relapse and require a more careful follow-up.
Different subcellular localization of ALCAM molecules in neuroblastoma: Association with relapse
ROSSELLO, ARMANDO;
2010-01-01
Abstract
Background: The Activated Leukocyte Cell Adhesion Mol. (ALCAM/CD166), involved in nervous system development, has been linked to tumor progression and metastasis in several tumors. No information is available on ALCAM expression in neuroblastoma, a childhood neoplasia originating from the sympathetic nervous system. Methods: ALCAM expression was analyzed by immunofluorescence and immunohistochem. on differentiated neuroblastoma cell lines and on archival specimens of stroma-poor, not MYCN amplified, resectable neuroblastoma tumors, resp. Results: ALCAM is variously expressed in neuroblastoma cell lines, is shed by metalloproteases and is cleaved by ADAM17/TACE in vitro. ALCAM is expressed in neuroblastoma primary tumors with diverse patterns of subcellular localization and is highly expressed in the neuropil area in a subgroup of cases. Tumor specimens showing high expression of ALCAM at the membrane of the neuroblast body or low levels in the neuropil area are assocd. with relapse (P=0.044 and P<0.0001, resp.). In vitro differentiated neuroblastoma cells show strong ALCAM expression on neurites, suggesting that ALCAM expression in the neuropil is related to a differentiated phenotype. Conclusion: Assessment of ALCAM localization by immunohistochem. may help to identify patients who, in the absence of neg. prognostic factors, are at risk of relapse and require a more careful follow-up.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
