BCR-ABL抑制剂STI571对慢性髓系白血病细胞株K562中SARI基因表达影响的研究

为了探讨抑癌基因SARI(suppressor of AP-1regu lated by IFN)在慢性髓系白血病(CML)中表达调控可能的分子机制,收集了46名CML患者和40名健康志愿者外周血样品,使用实时定量PCR技术检测2组人群中SARI基因的相对表达水平。在体外以CML细胞株K562为研究模型,使用BCR-ABL抑制剂STI571(im atinib)处理K562细胞,用实时定量PCR技术检测SARI基因的相对表达水平。结果表明,CML患者外周血中SARImRNA相对表达量明显低于健康志愿者,2组间具有明显的统计学差异(p<0.001)。使用STI571(2.5μm o l/L)处理K562细胞24小时后SARImRNA相对表达量明显高于未处理K562细胞,两组间差异具有显著性(p<0.001)。结论:CML患者外周血SARImRNA表达水平降低可能与该疾病的发生发展过程相关联,而且SARI基因表达下调与BCR-ABL抑制作用有关。本研究为CML患者基因治疗的研究提供了新线索。

Site discrepancy of synonymous codon usage in SARS coronavirus and other viruses in Coronaviridae

The synonymous codon usage in the translational initiation and termination regions of genes of severe acute respiratory syndrome (SARS) coronavirus and five other viruses in Coronaviridae was systematically analyzed.The results indicate that most minor codons for these coronaviruses are preferentially used in the initial and terminal region.The minor codons preferentially used in the initial region are thought to have a negative effect on gene expression,which can be explained by the minor codon modulator hypothesis.It also indicates that the minor codons preferentially used in the terminal region may regulate the level of gene expression.The proposed results strongly imply that the minor codon modulator hypothesis can be applied to both some bacteria and some viruses.

Establishment of the Eukaryotic Cell Lines for Inducible Control of SARS-CoV Nucleocapsid Gene Expression

In order to establish the eukaryotic cell lines for inducible control of SARS-CoV nucleocapsid gene expression.The recombinant plasmid of pTRE-Tight-SARS-N was constructed by using the plasmid p8S as the PCR template which contains a cDNA clone covering the nucleocapsid gene of SARS-CoV HKU-39449. Restriction enzymes digestion and sequence analysis indicated the recombinant plasmid of pTRE-Tight-SARS-N contained the nucleocapsid gene with the optimized nucleotide sequence which will improve the translation efficiency. Positive cell clones were selected by cotransfecting pTRE-Tight-SARS-N with the linear marker pPUR to BHK-21 Tet-on cells in the presence of puromycin. A set of double-stable eukaryotic cell lines (BHK-Tet-SARS-N) with inducible control of the SARS-CoV neucleocapsid gene expression was identified by using SDS-PAGE and Western-blot analysis. The expression of SARS-CoV nucleocapsid protein was tightly regulated by the varying concentration of doxcycline in the constructed double-stable cell line. The constructed BHK-Tet-SARS-N cell strains will facilitate the rescue of SARS-CoV in vitro and the further reverse genetic research of SARS-CoV.

A Method for Sea Surface Wind Field Retrieval from SAR Image Mode Data

To retrieve wind field from SAR images, the development for surface wind field retrieval from SAR images based on the improvement of new inversion model is present. Geophysical Model Functions （GMFs） have been widely applied for wind field retrieval from SAR images. Among them CMOD4 has a good performance under low and moderate wind conditions. Although CMOD5 is developed recently with a more fundamental basis, it has ambiguity of wind speed and a shape gradient of normalized radar cross section under low wind speed condition. This study proposes a method of wind field retrieval from SAR image by com-bining CMOD5 and CMOD4 Five VV-polarisation RADARSAT2 SAR images are implemented for validation and the retrieval re-suits by a combination method （CMOD5 and CMOD4） together with CMOD4 GMF are compared with QuikSCAT wind data. The root-mean-square error （RMSE） of wind speed is 0.75 m s-1 with correlation coefficient 0.84 using the combination method and the RMSE of wind speed is 1.01 m s-1 with correlation coefficient 0.72 using CMOD4 GMF alone for those cases. The proposed method can be applied to SAR image for avoiding the internal defect in CMOD5 under low wind speed condition.