Cell adhesion molecules (CAMs) are expressed ubiquitously. Each of the four families of CAMs is comprised of glycosylated, membrane-bound proteins that participate in multiple cellular processes including cell-cell communication, cell motility, inside-out and outside-in signaling, tumorigenesis, angiogenesis and metastasis. Intercellular adhesion molecule-2 (ICAM-2), a member of the immunoglobulin superfamily of CAMs, has six N-linked glycosylation sites at amino acids (asparagines) 47, 82, 105, 153, 178 and 187. Recently, we demonstrated a previously unknown function for ICAM-2 in tumor cells. We showed that ICAM-2 suppressed neuroblastoma cell motility and growth in soft agar, and induced a juxtamembrane distribution of F-actin in vitro. We also showed that ICAM-2 completely suppressed development of disseminated tumors in vivo in a murine model of metastatic NB. These effects of ICAM-2 on NB cell phenotype in vitro and in vivo depended on the interaction of ICAM-2 with the cytoskeletal linker protein alpha-actinin. Interestingly, ICAM-2 did not suppress subcutaneous growth of tumors in mice, suggesting that ICAM-2 affects the metastatic but not the tumorigenic potential of NB cells. The goal of the study presented here was to determine if the glycosylation status of ICAM-2 influenced its function in neuroblastoma cells.
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05/28/13