The Clinical Value Of Expression Of Cyclin B1 In Adult Patients With Acute Leukemia

Objective: To investigate the clinical values of expression of cyclin Bl in adult patients with acute leukemia (AL) The significant characteristic of acute leukemia is out of control in cells prolife -ration. Cyclin Bl plays an important role in promoting cells into mitosis. It acts as a regulator of cyclin Bl-p34cdc2 complex. P21cipl is a partner of the WAF1 families, which is able to inhibit active the complexes, overexpression and non-sequence expression of cyclin Bl protein has been reported in several acute leukemia cell lines, but little is known about the gene expression of cyclin Bl and its function in clinical AL patients. Through our investigation, we try to find out the function and clinical value of cyclin B1 in adult acute leukemia.Methods: The proteins expression of cyclin B1 p21 pi70 and CD34 were measured in 85 adult de novo acute leukemia patients' bone marrow samples 10 samples of continue complete remission (CCR) patients and 17 normal controls (NC) with flow cytometric analysis. The mRNA expression of cyclin Bl, p21, MRP, proliferation cell nuclear antigen ( PCNA ) topoisomerase II ( TOPOII ) andbcl-2 in them were measured by semi quantify reverse transcription polymers chain reaction (RT-PCR). Results: 1 Flow cytometric analysis results1.1 cyclin Bl protein expression in de novo AL patients (M=21.4%) was significant higher then NC (M=2.6%) (PO.001), there was no difference between AL and ALL (P=0.638). In the relapse AL patients, expression of cyclin Bl (M=l 1.4%) was higher than NC(P<0.05) but was lower than AL(P<0.01), there was no difference between the remission cases(M=3.6%) and NC(.P=0.21).The same as between CCR patients(M=2.8%)and NC(P=0.694).1.2 The p21 protein expression in De novo AL patients (M=6.2%)was significant higher then NC(M=2.5%) (P< 0.01), AML and All group had no difference (P=0.366).1.3 All patients whose cyclin Bl overexpresed had non-sequence expression of cyclin Bl(high express in Gi/S phase).2 Semi RT-PCR resultrthe expression of cyclin B1 mRNA in De novo AL patients(M=0.543) was significantly higher then NC(M=0) (P<0.01), but there was no difference between AML and ALL(P=0.763). In the relapse AL patients, (M=0.376) was higher than NC(P<0.05) but was lower than AL(jP<0.01), there was no difference between the remission cases, CCR patients (M=0) and NC(P>0.05).3 A negative correlation between the protein expression levels of cyclin Bl and p21 was observed (r=-0.266 PO.05), and so was the relationship between their gene expression.The cyclin Bl and p21 gene expression and corresponding protein expression were generally correlated (rcyciin Bi-0.620, rp21=0.356).4 The cyclin Bl protein expression and proliferation index (PI) levels, the cyclin Bl and PCNA gene expression levels were generally correlation (rPI=0.7314, rPcNA=0.7152).5 Remission rate (CR+PR) was higher in high cyclin Bl expression patients (43/64,67.18%)than that in normal cyclin Bl expression patients (6/21, 28.57?o)(P<0.01). Cyclin Bl was an important influential factor of CCR (b= 1.9401 r=0.2091 PO.001 (cox regression analysis)) and remission rate(b=05.8457 r=0.3279 P<0.005).The relapse rate was higher in high express cyclin Bl patients (17/40,42.05%) than that in normal cyclin Bl expression patients(l/7,14.29%) (P<0.01). Higher expression of cyclin Bl may have longer survival ratio.6 In non-drug resistance group, the cyclin Bl expression (M=22.6%) was higher then the drug resistance group ( M=14.3% ) (P<0.05). There was general correlationbetween cyclin B1 and TOPOII a TOPOIIP (rTOPOII . =0.472, r TOPOM e =0.683 P<0.01).In resistance patients .There was no correlation between cyclin Bl and p170 MRP bcl-2.Conclusion: Overexpression of cyclin Bl and abnormal coordinated expression pattern of cyclin B1 and p21 may be implicated occurrence and progression for AL. Expression of cyclin Bl was the most important avail factor for AL patients in overall survival, remission phases.