Over-expression of bone sialoprotein enhances bone @entity3 of @entity1 XXXX cells in a @entity19 model.

@entity1 @entity0 @entity5 @entity19 @entity16240 @entity79 @entity5154 @entity3 @entity2834
Bone sialoprotein ( @entity16240 ) is a major non-collagenous protein found almost exclusively in bone and other mineralized tissues including enamel, dentin and cementum. Although a role for @entity16240 in mineralization has been indicated, @entity16240 also appears to function in patho-physiological processes, including the @entity3 of @entity0 cells to bone. The purpose of this study was to determine the role of @entity16240 in the homing of @entity5 cells and to provide insights into the role of @entity16240 in physiological as well as pathological processes. We established cultures of MDA-231 @entity0 cells stably transfected with DNA constructs of pIRES2-EGFP (green fluorescent protein) expressing @entity1 @entity16240 ( @entity16240 ) cDNA (231BSP) under a @entity2834 promoter, or with an antisense sequence of @entity16240 cDNA (231BSPAS), or with an empty vector as a control (231EV). These 3 cell groups were selected for @entity5154 resistance using G418 and analyzed by flow cytometry for GFP expression. The resultant cultured cells expressed different levels of @entity16240 as detected by RT-PCR and Western blot. Among the three, 231BSP expressed the highest levels of @entity16240 while 231BSPAS expressed the lowest. The capacity of the @entity5 cells to metastasize to bone was determined in @entity19 (5 in each group) by intra-cardiac injection of the cells from the 3 different groups. Four weeks after inoculation, radiological examination revealed that all the 5 @entity19 in the 231BSP cell group had developed osteolytic bone @entity3 . In the 231BSPAS group only 1 @entity19 demonstrated metastatic @entity79 while 3 out of 5 @entity19 in the control group (231EV) developed metastatic lesions in the bone. These results strongly suggest that @entity16240 over-expression in @entity1 @entity5 cells can enhance bone @entity3 of MDA-231 cells whereas repressed expression of @entity16240 , using antisense @entity16240 cDNA, inhibits this effect in a @entity19 model.
