Résumé
<p><b>OBJECTIVE</b>To investigate the effect of CXCR4 gene on the proliferation, adhesion, invasion and tumorigenicity of a human monocytic leukemic cell line SHI-1.</p><p><b>METHODS</b>The lentivirus vector silencing the expression of CXCR4 was constructed for infection of SHI-1 cells silencing expression of CXCR4 in SHI-1 cells. The expression of CXCR4, MMP-2 and MMP-9 was detected by real time PCR. The expression of CXCR4 on membrane of SHI-1 cells was detected by flow cytometry. The SHI-1 cell proliferation ability was detected by MTT. The co-culture system of the leukemia cells and bone marrow stromal cells was used to detect the adhesion and migration ability of leukemia cells. SHI-1 cells were inoculated subcutaneously in nude mice to investigate the growth ability in vivo.</p><p><b>RESULTS</b>After SHI-1 cells were infected by lentivirus silencing expression of CXCR4, the expression of CXCR4 mRNA in SHI-1 CXCR-4i cells decreased by 76% as compared with expression of SHI-1/NC of negative control virus, the expression of CXCR4 on membrane of SHI-1/CXCR4i obviously downregulated; the expression of MMP-2 and MMP-9 in SHI-1/CXCRi cells also declined by 63% and 62% respectively; the proliferation ability of SHI-1/CXCR4i in vitro did not obviously changed, but the adhesion and trans-matrigel invasion ability significantly decreased, the SHI-1/CXCR4i cells could not form neoplasm subcutaneously in mice, but the SHI-1 and SHI-1/NC cells could form neoplasm subcutaneously in mice, and there was no significant difference in volumn of neoplasm mass.</p><p><b>CONCLUSION</b>The silencing expression of CXCR4 can decline the adhesion and migration ability of SHI-1 cells, and can completely suppress the formation of neoplasm subcutaneously, so the CXCR4 may serve as a target for treating leukemia.</p>
Sujets)
Animaux , Humains , Souris , Adhérence cellulaire , Lignée cellulaire tumorale , Prolifération cellulaire , Techniques de coculture , Lentivirus , Leucémie aigüe monoblastique , Anatomopathologie , Matrix metalloproteinase 2 , Métabolisme , Matrix metalloproteinase 9 , Métabolisme , Cellules souches mésenchymateuses , Souris nude , Invasion tumorale , Interférence par ARN , ARN messager , Récepteurs CXCR4 , Génétique , Transduction du signalRésumé
Objective To estimate the life expectancy of persons with physical disabilities in China based on data related to representative national disability.Methods Life table technique was used to estimate the life expectancy and its standard error by various characteristics on the basis of average mortality rates from the monitoring cases during 2007-2010.Results (1)Females were expected to live longer than males.The life expectancy at birth for females was 63 years with standard error(SE)=2.6 while for males it was 55 years(SE=3.1).(2)Persons aged 35-50 in urban areas had higher life expectancy than those in rural areas.(3)Life expectancy of persons with mild disability [62.5 years(SE=2.4)] was higher than that of persons with severe disability[42 years(SE=5.4)].(4)Life expectancies of persons with physical disability were much lower than that of the Chinese general population.Gaps of male and female life expectancy at birth were 17.1 years and 12.7 years,respectively.Conclusion Persons with physical disability had higher mortality and actions should be taken to improve their life expectancy,accordingly.