The Expression And Significance Of Circadian Clock Gene Bmal1and Per2in ALL Of Children

BackgroundAcute lymphoblastic leukemia is the most common blood cancer in children,accounting for about70%of childhood leukemia, its pathogenesis is not clear untilnow.And studies have found that abnormal expression of clock genes wich controlthe circadian rhythms is associated with the occurrence of tumors.It has been provedthat abnormal expression of clock genes is exist in acute and chronic myeloidleukemia. But there is few research on the relationship between the expression ofclock gene and the occurrence of acute lymphoblastic leukemia.ObjectiveThe aim is to study the expression of Bmal1and Per2respectively in patientswith Acute lymphoblastic leukemia(ALL),to investigate the expression of clock genesin children with acute lymphoblastic leukemia, initially revealed the role of clockgenes play in the pathogenesis of acute lymphoblastic leukemia.Methods1. To select newly diagnosed ALL patients30cases for the experimental group1，and complete remission ALL patients30cases for the experimental group2， children who came to have medical examination in the outpatient30cases as thehealthy control group. The inclusion criteria of experimental group refered to the2006treatment recommendations of children with acute lymphoblastic leukemiatreatment. To be enrolled in this study,patients had to be previously untreatedwith diseases which can affect the expression of clock genes,including obesity,cardiovascular disease, other cancers and sleep cycle disorders.2. To extract2ml of peripheral venous blood from each of the experimental andcontrol group with sterile syringe fastly at06：00am, and put it into the tube withEDTA anticoagulan fastly,shake it gently.3. To separate peripheral blood mononuclear cells by density gradient centrifugation,and draw the white film.4. To extract the total RNA from peripheral blood mononuclear cells according tothe instructions of Trizol reagent, detect the purity of the extracted RNA.Tosynthesize the cDNA according to the operating step of reverse transcription kit.To detect the expressions of Bmal1mRNA and Per2mRNA by real-time PCR.Results1. The expression of Bmal1mRNA and Per2mRNA in newly diagnosed ALLpatients compared with the control group was statistically significant different(P<0.05).The expression level of Per2mRNA from newly diagnosed ALLpatients is lower than the control group;on the contrary，the expression level ofBmal1mRNA from newly diagnosed ALL patients is lower than the controlgroup.2. The expression of Bmal1mRNA and Per2mRNA in complete remission ALLpatients compared with the control group was statistically significant different(P<0.05). The expression of both of the Bmal1mRNA and Per2mRNA from thecomplete remission ALL group are reduced compared with the control group.3. The expression of Bmal1mRNA and Per2mRNA in newly diagnosed ALLpatients compared with the complete remission ALL group was statisticallysignificant different (P<0.05).The expression of both of the Bmal1mRNA and Per2mRNA from the complete remission ALL group are reduced compared withthe newly diagnosed ALL group.Conclusion1. The abnormal expression of clock genes Bmal1mRNA and Per2mRNA are existin the peripheral blood mononuclear cells from children with ALL，and may playan important role in the incidence of ALL in children;2. Chemotherapy drugs can change the expression of clock genes.