Metabolism of @entity1426 in @entity1 XXXX cell lines.

@entity1 @entity1421 @entity117 @entity2 @entity2664 @entity1426 @entity3009 @entity460 @entity3365 @entity151
The metabolism of @entity1426 (AA) was studied in two @entity2 cell lines (NCI-H322 and NCI-H358) and two @entity151 cell lines (NCI-H69 and NCI-H128). Exogenous AA was metabolized only in the NCI-H322 and NCI-H358 cells. There was no detectable metabolism of AA in @entity1 or @entity1 cells, either in the presence or the absence of the @entity460 ionophore @entity3365 . The major metabolite of AA isolated from both NCI-H322 and NCI-H358 cells was @entity1421 ( @entity1421 ). Prostaglandin endoperoxide synthase activities, expressed as immunoreactive @entity1421 (pmol/min/mg protein), were 10.3 +/- 0.28 (SD) and 4.8 +/- 0.48 in NCI-H358 and NCI-H322 cells, respectively. The rate of production of @entity1421 by both NCI-H358 and NCI-H322 cells was linear up to 10 min. Production of @entity1421 in both cell lines was dependent upon substrate concentration and was maximal above 17 microM AA. Moreover, @entity1421 did not undergo further metabolism by either the NCI-H358 or the NCI-H322 cells. @entity117 (0.1 mM), a cyclooxygenase inhibitor, decreased @entity1421 production by 77 and 60% in NCI-H358 and NCI-H322 cells, respectively. In the presence of exogenous AA the @entity460 ionophore, @entity3365 (20 microM), stimulated @entity1421 production in NCI-H322 cells by almost 2-fold, although it did not affect @entity1421 production in the NCI-H358 cells. In contrast, @entity3365 stimulated the endogenous production of @entity1421 in both NCI-H322 and NCI-H358 cells by 4- and 9-fold respectively. In addition, both the NCI-H358 and NCI-H322 cell lines were susceptible to the cytotoxic effects of the anticancer agent @entity2664 in both a time and concentration dependent manner. In contrast, the two cell lines lacking detectable @entity3009 synthesis activity, NCI-H69 and NCI-H128 were unaffected by treatment with @entity2664 . These results illustrate that there are major differences in the abilities of @entity1 @entity2 cell lines to biosynthesize and release @entity1421 . It is conceivable that such differences might have exploitable diagnostic and/or therapeutic implications.
