Persistent alpha 1 integrin subunit expression in human neuroblastoma cell lines which overexpress N-myc and downregulate other integrin subunits

Neuroblastoma is characterized by amplification and overexpression of N-myc. N-myc down-regulates expression of the beta 1 integrin extracellular matrix receptor, however, some beta 1 was found on the surface of N-myc overexpressing neuroblastoma cell lines. It was determined that the alpha 1 subunit is expressed in the cells, associates with beta 1 and is present on the cell surface. Interestingly, the level of alpha 1 was reduced marginally when compared to beta 1. Finally, overexpression of N-myc alters cell morphology on extracellular matrix proteins with persistence of alpha 1 beta 1-dependent responses. Our work supports the conclusion that altered integrin expression may be an important factor in human neuroblastoma.