Effects Of Biological Behaviour Of RNA Silencing Of CXCR₄ Expression On Cocultured Jurkat Cell

Objective: Acute lymphoblastic leukemia (ALL) is one of the most frequent malignant tumour of paediatrics.Leukemia cell can generally infiltrate skeleton, liver, spleen, lymphaden and so on.A critical thing to affect children with ALL on obtaining long term survival is prevention and cure on heper-marrow leukemia.Chemotatic factor CXCR4 is ligand of stromal cell derived factor(SDF-1), which the combition of two factors can play an import part in the regulation of hematopoisis systema .SDF-1/CXCR4 axis can not only retain survival and proliferation on normal hematopoietic cell,but also on malignant cell proliferation and infiltrate blood,bone marrow,lemphaden.RNA interference (RNAi),an original technique on gene-interruption,can silmply and affectively depress definite gene expression as a specific and ultility silencing effect,aready generally used on antineoplastic gene therapy. Jurkat cell line is a kind of leukemia cell line originating from genetic of lymphatic system.The specific siRNA of CXCR4 plasmid vector was constructed and then transfected into the cultured Jurkat cell line by using RNAi technique .Reverse transcription-polymerase chain reaction (RT-PCR)was used to detect the expression of CXCR4 mRNA respectively.Cell cycle distribution and cell apoptosis were determined by flow cytometry.CXCR4 silence by siRNA can inhibit the growth of Jurkat cells through inducing apoposis and cell cycle arrest.In short,it offers a new approach to prevention and cure of ALL.Methods:.The specific siRNA was designed and chemically synthesized evidence with characteristic target sequence of CXCR4 cDNA.The Jurkat cell line were divided three groups:Group A:blank group(not adding CXCR4-siRNA , Non-silencing dsRNA and DMRIE-C),Group B:negative control group(adding Non-silencing dsRNA and DMRIE-C), Group C:purpose group(CXCR4-siRNA and DMRIE-C).The solution was diluted into concentration of 80nM. The siRNA of CXCR4 was transfected into the cultructed Jurkat cell line with DMRIE-C.After 48 hours,reverse transcription-polymerase chain reaction(RT-PCR) were used to detect the expression of CXCR4mRNA respectively.Cell cycle distribution and cell apoptosis were determined by flow cytometry.Results:The blank group and negative control group of comparison difference was not statistically significant,which purpose group comparison with was statistically significant.In comparison with those in purpose and blank group,the levers of CXCR4 mRNA were decreased highly(56.9%±1.4%vs68.3%±2.4%).The percentage of apoptosis cells in CXCR4 group was significantly higher than that in negative control group(20.7%±1.7%vs2.98%±0.3%)and the cell percentage were increased at G0/G1 (35.9%±2.0%vs18.1%±1.3%),but decreased at G2/M phase and S phase(20.1%±1.1%vs27.7%±1.5%;44.4%±3.0%vs54.2%±2.6%).Conclusions:1.RNAi technique was found to have obvious inhibitory effect on CXCR4 gene of Jurkat cell and the levers of CXCR4 mRNA of Jurkat cell was found to reduce utility.2. CXCR4 silence by the specific siRNA can inhibit the growth of Jurkat cells through inducing apoposis and cell cycle arrest.