Cellular and plasma fibronectins are heterodimers consisting of similar but not identical polypeptides. The differences between fibronectin subunits are due in part to the variability of internal primary sequences. This results from alternative splicing in at least two regions (ED and IIICS) of the pre‐mRNA. The complete primary structure of human fibronectin, including most of the internal variations, has been determined by sequencing a series of overlapping cDNA clones. In total, they covered 7692 nucleotides and represented the mRNA sequence coding from the amino terminus of the mature protein to the poly(A) tail. The deduced amino acid sequence of fibronectin has been analysed in terms of the arrangement of internal homologies and the different binding domains.

A potent tyrosine kinase inhibitor, lavendustin A [1], has been isolated from a butyl acetate extract of Streptomyces griseolavendus culture filtrate. It inhibits epidermal growth factor receptor-associated tyrosine kinase with an IC50 of 4.4 ng/ml, which is about 50 times more inhibitory than erbstatin. It does not inhibit protein kinase A or C. Its structure, determined by spectral data and total synthesis, is novel, having a tertiary amine in the center with substituted benzyl and phenyl groups. Lavendustin A competes with ATP and is noncompetitive with the peptide. Its structure-activity relationship is discussed.

The present data revealed significant a contribution of the AT1-R/NF-kappaB pathway to diabetes-induced retinal inflammation, providing a mechanistic reason for targeting AT1-R or NF-kappaB in the treatment of diabetic retinopathy.

Caspase-3(-like) proteases play important roles in controlling mammalian apoptosis. However, the downstream events from the caspase-3(-like) protease activation to death of cells are still unclear. Previously, we reported that hydrogen peroxide (H 2 O 2 ) was generated by the activation of caspase-3(-like) proteases in the process of tyrosine kinase inhibitor-induced apoptosis in human small cell lung carcinoma Ms-1 cells. In the present study, we examined whether generation of H 2 O 2 is a critical event for the apoptotic pathway downstream of caspase-3(-like) protease activation by various anticancer drugs. Anticancer drugs such as camptothecin, vinblastine, inostamycin, and adriamycin induced activation of caspase-3(-like) proteases and apoptosis. Generation of H 2 O 2 was commonly detected after treatment with each of the four anticancer drugs, and scavenging of H 2 O 2 caused cells to fail to undergo apoptosis. Moreover, anticancer drug-induced H 2 O 2 production was inhibited not only by an inhibitor of caspase-3(-like) proteases but also by diphenyleneiodonium chloride, an inhibitor of flavonoid-containing enzymes such as NADPH oxidase. However, activation of caspase-3(-like) proteases was not inhibited by diphenyleneiodonium chloride. These findings suggest that activation of caspase-3(-like) proteases by various anticancer drugs causes generation of H 2 O 2 presumably through the activation of NADPH oxidase, thereby inducing apoptosis.

We previously designed and synthesized an NF-B inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), that showed anti-inflammatory activity in vivo. In the present study we looked into its mechanism of inhibi-

High expression of CD30 and JunB is characteristic of tumor cells in anaplastic large cell lymphoma (ALCL) and Hodgkin lymphoma (HL). Possible interactions of CD30 and JunB were examined in this study. We found that the CD30 promoter in tumor cells of both nucleophosmin (NPM)-anaplastic lymphoma kinase (ALK)-positive and NPM-ALK-negative ALCL and HL is regulated by a constitutively active CD30-extracellular signal-regulated kinase (ERK) 1/2 mitogen-activated protein kinase (MAPK). Phosphorylation of ERK1/2 MAPK was confirmed in nuclei of tumor cells in both ALCL and HL. CD30-ERK1/2 MAPK signals induce JunB expression, which maintains high activity of the CD30 promoter. JunB induction seems to be largely independent of nuclear factor KB in ALCL and HL. These results show a common mechanism of CD30 overexpression in ALCL and HL, although the outcome of CD30 signaling differs between NPM-ALK-positive ALCL and NPM-ALK-negative ALCL, cutaneous ALCL, and HL as we recently reported. (Cancer Res 2005; 65(17): 7628-34)

(−)-DHMEQ, a newly designed NF-B inhibitor, inhibited RANKL-induced osteoclast differentiation in mouse BMMs through downregulation of the induction of NFATc1, an essential transcription factor of osteoclastogenesis.Introduction: Bone destruction is often observed in advanced case of rheumatoid arthritis and neoplastic diseases, including multiple myeloma. Effective and nontoxic chemotherapeutic agents are expected for the suppression of these bone destructions. RANKL induces activation of NF-B and osteoclastogenesis in bone marrow-derived monocyte/macrophage precursor cells (BMMs). Targeted disruption or pharmacological suppression of NF-B result in impaired osteoclastogenesis, but how NF-B is involved in the regulation of osteoclastogenesis is not known. Materials and Methods:The effect of (−)-dehydroxymethylepoxyquinomicin [(−)-DHMEQ] on osteoclast differentiation was studied using a culture system of mouse BMMs stimulated with RANKL and macrophage colony-stimulating factor. The mechanism of the inhibition was studied by biochemical analysis such as immunoblotting and retroviral transfer experiments. Results: (−)-DHMEQ strongly inhibited RANKL-induced NF-B activation in BMMs and inhibited RANKL-induced formation of TRACP+ multinucleated cells. Interestingly, (−)-DHMEQ specifically inhibited the RANKL-induced expression of NFATc1 but not the expressions of TRAF6 or c-fos. Inhibition of osteoclast differentiation by (−)-DHMEQ was rescued by overexpression of NFATc1, suggesting that the inhibition is not caused by a toxic effect. Moreover, pit formation assays showed that (−)-DHMEQ also inhibited the bone-resorbing activity of mature osteoclasts. Conclusion:The inhibition of NF-B suppresses osteoclastogenesis by downregulation of NFATc1, suggesting that NFATc1 expression is regulated by NF-B in RANKL-induced osteoclastogenesis. Our results also indicate the possibility of (−)-DHMEQ becoming a new therapeutic strategy against bone erosion.

Background-Choroidal neovascularization (CNV) is a critical pathogenesis in age-related macular degeneration, the most common cause of blindness in the developed countries. The aim of the current study was to investigate the effect of lutein supplementation on the development of the murine model of laser-induced CNV together with underlying molecular mechanisms. Methods and Results-Mice were orally pretreated with lutein daily from 3 days before laser photocoagulation untill the end of the study. The index of CNV volume was significantly suppressed by the treatment with lutein, compared with vehicle-treated animals. Lutein treatment led to significant inhibition of macrophage infiltration into CNV and of the in vivo and in vitro expression of inflammation-related molecules including vascular endothelial growth factor, monocyte chemotactic protein Ϫ1, and intercellular adhesion molecule-1. Importantly, lutein suppressed IB-␣ degradation and nuclear translocation of nuclear factor (NF)-B p65 both in vivo and in vitro. Additionally, the development of CNV was significantly suppressed by inhibiting NF-B p65 nuclear translocation, to the levels seen in the lutein treatment. Conclusions-Lutein treatment led to significant suppression of CNV development together with inflammatory processes including NF-B activation and subsequent upregulation of inflammatory molecules, providing molecular evidence of potential validity of lutein supplementation as a therapeutic strategy to suppress CNV. (Arterioscler Thromb Vasc Biol.