0000000000725012
AUTHOR
Negusse Habtemichael
showing 2 related works from this author
The Mutation without childrenrgl Causes Ecdysteroid Deficiency in Third-Instar Larvae of Drosophila melanogaster
2000
Larvae homozygous for the recessive lethal allele without children(rgl) (woc(rgl)) fail to pupariate. Application of exogenous 20-hydroxyecdysone elicits puparium formation and pupation. Ecdysteroid titer measurements on mutant larvae show an endocrine deficiency in the brain-ring gland complex, which normally synthesizes ecdysone, resulting in a failure of the larvae to achieve a threshold whole body hormone titer necessary for molting. Ultrastructural investigation revealed extensive degeneration of the prothoracic cells of the ring gland in older larvae. The woc gene, located in polytene chromosomal region 97F, consists of 11 exons. A 6.8-kb transcript is expressed throughout development…
Inducible NO synthase confers chemoresistance in head and neck cancer by modulating survivin
2009
The dual role of the inducible NO synthase (iNOS) and NO signaling in head and neck squamous cell carcinoma (HNSCC) is a complex and can both promote or inhibit tumor progression. However, the underlying molecular mechanisms are not yet resolved in detail. We show for the first time that conditions, favoring low NO levels conferred resistance against cisplatin/taxol-induced apoptosis in HNSCC cell lines. Cytoprotection was mediated by survivin, because we observed its upregulation subsequent to low doses of the NO donors S-nitroso-N-acetyl-penicillamine (SNAP) and sodium nitroprusside (SNP) or ectopic expression of physiologic amounts of iNOS. Also, RNAi-mediated depletion of survivin block…