MicroRNAs （miRNAs） are endogenous, small, non-coding RNAs, which are capable of silencing gene expression at the post-transcriptional level. In this study, we report that miR-205 is significantly underexpressed in b...MicroRNAs （miRNAs） are endogenous, small, non-coding RNAs, which are capable of silencing gene expression at the post-transcriptional level. In this study, we report that miR-205 is significantly underexpressed in breast tumor compared to the matched normal breast tissue. Similarly, breast cancer cell lines, including MCF-7 and MDA-MB- 231, express a lower level miR-205 than the non-malignant MCF-10A cells. Of interest, ectopic expression of miR-205 significantly inhibits cell proliferation and anchorage independent growth, as well as cell invasion. Furthermore, miR- 205 was shown to suppress lung metastasis in an animal model. Finally, western blot combined with the luciferase reporter assays demonstrate that ErbB3 and vascular endothelial growth factor A （VEGF-A） are direct targets for miR-205, and this miR-205-mediated suppression is likely through the direct interaction with the putative miR-205 binding site in the 3＇-untranslated region （3＇-UTR） of ErbB3 and VEGF-A. Together, these results suggest that miR- 205 is a tumor suppressor in breast cancer.展开更多
Metabolism of S-nitrosoglutathione （GSNO）, a major biologically active nitric oxide （NO） species, is catalyzed by the evolutionally conserved GSNO reductase （GSNOR）. Previous studies showed that the Arabidopsis ...Metabolism of S-nitrosoglutathione （GSNO）, a major biologically active nitric oxide （NO） species, is catalyzed by the evolutionally conserved GSNO reductase （GSNOR）. Previous studies showed that the Arabidopsis GSNOR1/ HOT5 gene regulates salicylic acid signaling and thermotolerance by modulating the intracellular S-nitrosothiol level. Here, we report the characterization of the Arabidopsisparaquat resistant2-1 （par2-1） mutant that shows an anti-cell death phenotype. The production of superoxide in par2-1 is comparable to that of wild-type plants when treated by paraquat （1,1＇-dimethyl-4,4＇-bipyridinium dichloride）, suggesting that PAR2 acts downstream of superoxide to regulate cell death. PAR2, identified by positional cloning, is shown to be identical to GSNOR1/HOT5. The par2-1 mutant carries a missense mutation in a highly conserved glycine, which renders the mutant protein unstable. Compared to wild type, par2-1 mutant has a higher NO level, as revealed by staining with 4,5-diaminofluorescein diacetate. Consistent with this result, wild-type plants treated with an NO donor display resistance to paraquat. Interestingly, the GSNOR1/HOT5/PAR2 protein level, other than its steady-state mRNA level, is induced by paraquat, but is reduced by NO donors. Taken together, these results suggest that GSNOR1/HOT5/PAR2 plays an important role in regulating cell death in plant cells through modulating intracellular NO level.展开更多
Mukerjee and Wu（2001） employed projective geometry theory to find the wordlength pattern of a regular mixed factorial design in terms of its complementary set, but only for the numbers of words of length 3 or 4. In ...Mukerjee and Wu（2001） employed projective geometry theory to find the wordlength pattern of a regular mixed factorial design in terms of its complementary set, but only for the numbers of words of length 3 or 4. In this paper, by introducing a concept of consulting design and based on the connection between factorial design theory and coding theory, we obtain some combinatorial identities that relate the wordlength pattern of a regular mixed-level （2^r）2^n factorial design to that of its consulting design. Consequently, a general rule for identifying minimum aberration （2^r）2^n factorial designs through their consulting designs is established. It is an improvement and generalization of the related result in Mukerjee and Wu（2001）.展开更多
Long-period acceleration spectra determined by seismic safety evaluation for project sites are generally lower than that given by relative code spectra.In this paper,we discuss the recurrence periods corresponding to ...Long-period acceleration spectra determined by seismic safety evaluation for project sites are generally lower than that given by relative code spectra.In this paper,we discuss the recurrence periods corresponding to the code spectra of different periods,by using ground motion attenuation laws for sites of types Ⅰ and Ⅲ.We show the results that the longer the periods of code spectra are commonly the more conservative the seismic level is.As for the project examples in this paper,when the periods are longer than 3.7 or 5.2 seconds for sites of types Ⅰ or Ⅲ,the recurrence periods corresponding to the code spectra are longer than 5000 years.We suggest that some problems need to be further discussed,including the reliability of the present attenuation laws,the performance of those project structures that suffer long period seismic waves and have been designed according to the conservative codes,and the effects of ground motion parameters such as velocity and displacement on seismic design.展开更多
文摘MicroRNAs （miRNAs） are endogenous, small, non-coding RNAs, which are capable of silencing gene expression at the post-transcriptional level. In this study, we report that miR-205 is significantly underexpressed in breast tumor compared to the matched normal breast tissue. Similarly, breast cancer cell lines, including MCF-7 and MDA-MB- 231, express a lower level miR-205 than the non-malignant MCF-10A cells. Of interest, ectopic expression of miR-205 significantly inhibits cell proliferation and anchorage independent growth, as well as cell invasion. Furthermore, miR- 205 was shown to suppress lung metastasis in an animal model. Finally, western blot combined with the luciferase reporter assays demonstrate that ErbB3 and vascular endothelial growth factor A （VEGF-A） are direct targets for miR-205, and this miR-205-mediated suppression is likely through the direct interaction with the putative miR-205 binding site in the 3＇-untranslated region （3＇-UTR） of ErbB3 and VEGF-A. Together, these results suggest that miR- 205 is a tumor suppressor in breast cancer.
基金We thank Dr Gary Loake （University of Edinburgh, UK） for providing gsnor1-3 seeds. We are grateful to Drs Chuanyou Li, Shuhua Yang and Yiqin Wang for critically reading the manuscript. This study was supported by grants from the National Natural Science Foundation of China （30330360）, the Ministry of Science and Technology of China （2006AA 10A 112） and the Chinese Academy of Sciences （KSCX2-YW-N-015）.
文摘Metabolism of S-nitrosoglutathione （GSNO）, a major biologically active nitric oxide （NO） species, is catalyzed by the evolutionally conserved GSNO reductase （GSNOR）. Previous studies showed that the Arabidopsis GSNOR1/ HOT5 gene regulates salicylic acid signaling and thermotolerance by modulating the intracellular S-nitrosothiol level. Here, we report the characterization of the Arabidopsisparaquat resistant2-1 （par2-1） mutant that shows an anti-cell death phenotype. The production of superoxide in par2-1 is comparable to that of wild-type plants when treated by paraquat （1,1＇-dimethyl-4,4＇-bipyridinium dichloride）, suggesting that PAR2 acts downstream of superoxide to regulate cell death. PAR2, identified by positional cloning, is shown to be identical to GSNOR1/HOT5. The par2-1 mutant carries a missense mutation in a highly conserved glycine, which renders the mutant protein unstable. Compared to wild type, par2-1 mutant has a higher NO level, as revealed by staining with 4,5-diaminofluorescein diacetate. Consistent with this result, wild-type plants treated with an NO donor display resistance to paraquat. Interestingly, the GSNOR1/HOT5/PAR2 protein level, other than its steady-state mRNA level, is induced by paraquat, but is reduced by NO donors. Taken together, these results suggest that GSNOR1/HOT5/PAR2 plays an important role in regulating cell death in plant cells through modulating intracellular NO level.
文摘Mukerjee and Wu（2001） employed projective geometry theory to find the wordlength pattern of a regular mixed factorial design in terms of its complementary set, but only for the numbers of words of length 3 or 4. In this paper, by introducing a concept of consulting design and based on the connection between factorial design theory and coding theory, we obtain some combinatorial identities that relate the wordlength pattern of a regular mixed-level （2^r）2^n factorial design to that of its consulting design. Consequently, a general rule for identifying minimum aberration （2^r）2^n factorial designs through their consulting designs is established. It is an improvement and generalization of the related result in Mukerjee and Wu（2001）.
基金The project is sponsored under the Key Scientific Researchand Development Programof Zhejiang Province(2005C23075),China
文摘Long-period acceleration spectra determined by seismic safety evaluation for project sites are generally lower than that given by relative code spectra.In this paper,we discuss the recurrence periods corresponding to the code spectra of different periods,by using ground motion attenuation laws for sites of types Ⅰ and Ⅲ.We show the results that the longer the periods of code spectra are commonly the more conservative the seismic level is.As for the project examples in this paper,when the periods are longer than 3.7 or 5.2 seconds for sites of types Ⅰ or Ⅲ,the recurrence periods corresponding to the code spectra are longer than 5000 years.We suggest that some problems need to be further discussed,including the reliability of the present attenuation laws,the performance of those project structures that suffer long period seismic waves and have been designed according to the conservative codes,and the effects of ground motion parameters such as velocity and displacement on seismic design.
