We have shown that lysophosphatidylcholine (lyso-PC) increases endothelial nitric-oxide synthase (eNOS) expression at the transcriptional level (Zembowicz, A., Tang, J.-L., and Wu, K. K. (1995) J. Biol. Chem. 270, 17006 -17010). To elucidate the mechanism by which lyso-PC increases the eNOS transcription, we identified Sp1 sites at ؊104 to ؊90 and PEA3 sites at ؊40 to ؊24 as being involved in lyso-PC-induced promoter activity. Site-directed mutagenesis of Sp1 sites resulted in a marked reduction of basal and lyso-PC-induced activity whereas PEA3 site mutation abrogated response to lyso-PC. Band shift assays revealed that lyso-PC augmented Sp1 binding activity. Pretreatment of cells or nuclear extracts with okadaic acid reduced the Sp1 binding activity. Furthermore, okadaic acid treatment abrogated the lyso-PC induced promoter augmentation. Lyso-PC increased the nuclear extract protein phosphatase 2A (PP2A) activity, which was suppressed by okadaic acid treatment. These results suggest that lyso-PC up-regulates eNOS transcription by a PP2A-dependent increase in Sp1 binding activity. Nitric oxide (NO)1 is an important mediator of diverse physiological and pathological processes, including vasodilation, cytotoxicity, and neurotransmission (1-4). Its biosynthesis is catalyzed by nitric-oxide synthase (NOS). Three isoforms of NOS, i.e. neuronal NOS (nNOS or NOS-I), inducible-NOS (iNOS or NOS-II), and endothelial-NOS (eNOS or NOS-III) have been identified and characterized (5-7). NOS-I and -III are constitutively expressed. The inducible form is expressed by stimulation with several inflammatory and mitogenic mediators (8, 9). Altered endothelial NO productions have been implicated in several important cardiovascular disorders: hypertension, atherosclerotic heart disease, and diabetes. The mechanism by which NO synthesis is deranged in these disorders remained unclear. Although NOS-III is considered to be a housekeeping gene, recent studies have provided evidence to suggest that NOS-III is induced by shear stress (10), physical exercise (11), hypoxia (12), estrogen treatment (13), lysophosphatidylcholine (lyso-PC or LPC), and low levels of oxidized low density lipoprotein (14, 15). These findings imply that induction of NOS-III plays an important role in protecting vascular integrity under stress. Work from our laboratory has shown that lyso-PC increases NOS-III expression at the transcriptional level (14). However, the mechanism by which lyso-PC and other inducing agents increase NOS-III gene transcription remains to be elucidated.The 5Ј-flanking region of human eNOS gene has been cloned and sequenced (16). The region adjacent to the transcription initiation sites is TATA-less and GC-rich. Functional analysis of the promoter activity conferred by the 5Ј-flanking region has shown that a canonical Sp1 site situated between Ϫ104 to Ϫ90 is required for the basal promoter activity (17). However, it is unclear whether this site is involved in lyso-PC-induced transcriptional activation. The purpose of this study is to ident...

From 1986 to 1998, 26 (23%) of 114 adult acute lymphoblastic leukemia (ALL) patients and 11 (4%) of 328 pediatric patients were found to have Philadelphia (Ph) chromosome. In the 30 patients with available data at diagnosis, 18 (60%) had extra-chromosomal abnormalities. They included 1q duplication (5/18, 28%), supernumerary Ph chromosome (4/18, 22%), 9p abnormalities (3/18, 17%), 7q deletion/monosomy 7 (3/18, 17%), trisomy 19 (1/18, 6%), and trisomy 8 (1/18, 6%). Excluding those with specific cytogenetic changes, only one patient had hyperdiploid karyotype with more than 50 chromosomes. The incidence of 1q duplication was higher and that of hyperdiploidy was lower in this study than has been previously reported. There was no prognostic implication of these additional cyto-