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991.
992.
IGF-1R tyrosine kinase expression and dependency in clones of IGF-1R knockout cells (R-) 总被引:1,自引:0,他引:1
Rosengren L Vasilcanu D Vasilcanu R Fickenscher S Sehat B Natalishvili N Naughton S Yin S Girnita A Girnita L Axelson M Larsson O 《Biochemical and biophysical research communications》2006,347(4):1059-1066
Insulin-like growth factor 1 receptor (IGF-1R) plays many crucial roles in cancer, like anti-apoptotic activity and necessity for transformation. IGF-1R knockout cells (R-) represent a useful tool for molecular mapping of biological properties of the receptor. R- cells have been shown to be refractory to transformation by viral and cellular oncogenes, highlighting the necessity of this receptor for transformation. Surprisingly, more recent studies have shown that these cells can undergo spontaneous transformation. This observation raises the question as whether R- cells over the years have acquired some properties mimicking those of IGF-1R. Using an IGF-1R inhibitor (cyclolignan PPP) we have identified clones of R- (R-s) that are sensitive to this compound. Since, PPP is closely related to podophyllotoxin, which is an efficient microtubule inhibitor, we first investigated if such a mechanism could explain the sensitivity to PPP. However, highly purified PPP showed no or very slight tubulin binding. Further analysis of R-s revealed expression of a 90 kDa protein being reactive to IGF-1R beta-subunit antibodies. This protein was weakly but constitutively tyrosine phosphorylated and was downregulated by siRNA targeting IGF-1R. This downregulation was paralleled by decreased R-s survival. Taken together, our study suggests that clones of R- express IGF-1R activity and dependency, which in turn may explain that R- can undergo spontaneous transformation. 相似文献
993.
994.
995.
A new cell line from larval fat bodies of the bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae) 总被引:1,自引:0,他引:1
Zhang H Zhang YA Qin Q Wang Y Li X Miao L Yin Z Zhang A Qu L Ding C 《In vitro cellular & developmental biology. Animal》2006,42(10):290-293
Summary A new cell line, designated IOZCAS-Ha-I, was initiated from the fat body of larvae of Helicoverpa armigera (Lepidoptera: Noctuidae) in TNM-FH medium containing 10% fetal bovine serum. Spherical cells were predominant among the various
cell types. The cell line showed a typical lepidopteran chromosome pattern ranging from 58 to 239 chromosomes in the majority
of the cells, it was confirmed to have originated from the H. armigera by the DNA amplification-fingerprinting polymerase chain reaction (DAF-PCR) technique. The new cell line was only slightly
susceptible to the multiple nucleocapsid nuclear polyhedrosis viruses (NPV) from H. armigera. 相似文献
996.
Alter J Lou F Rabinowitz A Yin H Rosenfeld J Wilton SD Partridge TA Lu QL 《Nature medicine》2006,12(2):175-177
For the majority of Duchenne muscular dystrophy (DMD) mutations, antisense oligonucleotide (AON)-mediated exon skipping has the potential to restore a functional protein. Here we show that weekly intravenous injections of morpholino phosphorodiamidate (morpholino) AONs induce expression of functional levels of dystrophin in body-wide skeletal muscles of the dystrophic mdx mouse, with resulting improvement in muscle function. Although the level of dystrophin expression achieved varies considerably between muscles, antisense therapy may provide a realistic hope for the treatment of a majority of individuals with DMD. 相似文献
997.
This article reports the concentrations of hexachlorocyclohexanes (HCHs) and dichloro-diphenyl-trichloroethanes (DDTs) in fresh Gentoo penguin (Pygoscelis Papua) droppings deposited on the Ardley Island (62°13′S, 58°56′W), West Antarctica, and those in the island's two lake cores. In the fresh penguin droppings, metabolites were the predominant constituents of the DDT group, most likely due to the ban on DDT use in agriculture and the higher stability of the metabolites in the environment. In contrast, γ-HCH comprised 66% of the total HCHs, apparently due to the continuous use of Lindane in the Southern Hemisphere. The concentrations of HCHs and DDTs in the fresh droppings are many times higher than those in penguin plume, the latter currently being used as biomaterial for monitoring coastal contaminations in Antarctica. Results of this study indicate that penguin droppings have a good potential for use as another biomonitoring material in detecting the organochlorine pesticides and other contaminants in the maritime Antarctic. Because penguin droppings can be well preserved in lake sediments, they also provide a good and continuous historical record of these contaminants. The slight increase of DDTs since the 1990s, as observed in the aged penguin droppings in the sediment cores, suggests there have been new inputs of DDT into the Antarctic coastal ecosystem, probably from the illegal use of DDT in the Southern Hemisphere. 相似文献
998.
Caspase-9 activation is critical for intrinsic cell death. The activity of caspase-9 is increased dramatically upon association with the apoptosome, and the apoptosome bound caspase-9 is the caspase-9 holoenzyme (C9Holo). In this study, we use quantitative enzymatic assays to fully characterize C9Holo and a leucine-zipper-linked dimeric caspase-9 (LZ-C9). We surprisingly show that LZ-C9 is more active than C9Holo for the optimal caspase-9 peptide substrate LEHD-AFC but is much less active than C9Holo for the physiological substrate procaspase-3. The measured Km values of C9Holo and LZ-C9 for LEHD-AFC are similar, demonstrating that dimerization is sufficient for catalytic activation of caspase-9. The lower activity of C9Holo against LEHD-AFC may be attributed to incomplete C9Holo assembly. However, the measured Km of C9Holo for procaspase-3 is much lower than that of LZ-C9. Therefore, in addition to dimerization, the apoptosome activates caspase-9 by enhancing its affinity for procaspase-3, which is important for procaspase-3 activation at the physiological concentration. 相似文献
999.
Codon usage patterns in Nematoda: analysis based on over 25 million codons in thirty-two species 总被引:1,自引:0,他引:1
Makedonka Mitreva Michael C Wendl John Martin Todd Wylie Yong Yin Allan Larson John Parkinson Robert H Waterston James P McCarter 《Genome biology》2006,7(8):R75-19
Background
Codon usage has direct utility in molecular characterization of species and is also a marker for molecular evolution. To understand codon usage within the diverse phylum Nematoda, we analyzed a total of 265,494 expressed sequence tags (ESTs) from 30 nematode species. The full genomes of Caenorhabditis elegans and C. briggsae were also examined. A total of 25,871,325 codons were analyzed and a comprehensive codon usage table for all species was generated. This is the first codon usage table available for 24 of these organisms. 相似文献1000.
Novel gene and gene model detection using a whole genome open reading frame analysis in proteomics 总被引:4,自引:1,他引:3
Fermin D Allen BB Blackwell TW Menon R Adamski M Xu Y Ulintz P Omenn GS States DJ 《Genome biology》2006,7(4):R35-13