@entity1 @entity0 MCF-7/AdrVp cells display a novel multidrug resistance phenotype that is characterized by the overexpression of a 95-kDa membrane glycoprotein ( @entity9485 ) and by marked reduction in intracellular @entity4349 accumulation, without overexpression of @entity1262 or the multidrug resistance protein MRP. @entity9485 is also highly expressed in multidrug-resistant @entity1 cells derived from a @entity1 @entity151 . Deglycoslyated @entity9485 from @entity1 cells was isolated by two-dimensional gel electrophoresis and then digested with trypsin. The tryptic peptides were analyzed by mass spectrometry and microsequencing. These analyses identified @entity9485 to be identical to NCA-90, the nonspecific cross-reacting antigen related to the @entity787 ( @entity787 ). Further confirmation that @entity9485 is indeed NCA-90 was obtained by Northern and Western blot studies using probes or antibodies specific for @entity9485 , NCA-90, or @entity787 family members. Western blot studies also revealed that @entity787 itself is overexpressed in MCF-7/AdrVp cells compared to parental MCF-7/W cells. The enforced expression of NCA-90 protein in HeLa cells stably transfected with NCA-90 cDNA did not result in increased resistance of the transfected cells to @entity5699 or a decrease in @entity5699 accumulation in the transfected cells compared to cells transfected only with the expression vector. However, a recent report by H. Kawaharata et al. (Int. J. @entity5 , 72: 377-382, 1997) of diminished accumulation, retention, and @entity137 of @entity632 in EJNIH3T3 cells in which enforced expression of @entity787 was accomplished leaves open the possibility that the overexpression of @entity787 , possibly in combination with that of NCA-90, could account at least in part for the drug resistant phenotype displayed by MCF-7/AdrVp cells.

The 95-kilodalton membrane glycoprotein overexpressed in novel multidrug-resistant @entity0 cells is NCA, the nonspecific cross-reacting antigen of XXXX .

@entity1 :: ('9606', 'Species') :: ['NCI-H1688', 'human', 'Human'] @entity632 :: ('MESH:D004317', 'Chemical') :: ['doxorubicin'] @entity1262 :: ('5243', 'Gene') :: ['P-glycoprotein'] @entity137 :: ('MESH:D064420', 'Disease') :: ['cytotoxicity'] @entity0 :: ('MESH:D001943', 'Disease') :: ['breast carcinoma'] @entity4349 :: ('CHEBI:48120', 'Chemical') :: ['anthracycline'] @entity5699 :: ('MESH:D003630', 'Chemical') :: ['daunorubicin'] @entity5 :: ('MESH:D009369', 'Disease') :: ['Cancer'] @entity787 :: ('1084', 'Gene') :: ['CEA', 'carcinoembryonic antigen'] @entity9485 :: ('4683', 'Gene') :: ['p95'] @entity151 :: ('MESH:D055752', 'Disease') :: ['small cell lung carcinoma']
@entity787 :: (1084,Gene) :: ['carcinoembryonic antigen']
