Expression And Clinic Significance Of Cyclin E And CDK2 In Uterine Smooth Muscle Tumors

Objective:We made a study of the expression of cyclin E and CDK2 in uterine smooth muscle tumors (USMTs) and the relation between cyclin E and CDK2 and the proliferation of uterine smooth muscle, and investigated the effect of cyclin E and CDK2 in the growth and development of uterine smooth muscle tumors (USMTs) and their clinic significance.Methods:1. Immunohistochemical technique (S-P method) was used to detect the protein expression of cyclin E, CDK2 and PCNA in 20 normal myometrium (M), 35 usual leiomyoma (UL), 18 leiomyosarcoma(LMS)and 22 borderline leiomyoma(BLM): Including 13 cellular leiomyoma (CL), 4 bizarre leiomyoma (BL) and 5 mitotically active leiomyoma (ML). Then we applied the image-analysis-system to detect the positive area of colouration and the average luminosity of cyclin E, CDK2 and PCNA respectively.2. The mRNA expression of cyclin E, CDK2 and PCNA in usual leiomyoma (UL) and normal myometrium (M) was detected by using semi-quantity reverse transcriptase polymerase chain reaction (RT-PCR) technique.Results: 1. The protein expression of cyclin E, CDK2 and PCNA in UL, BLM (including CL, BL and ML) and LMS were significantly higher than that in M and show a significant difference, P<0.05.The protein expression of cyclin E, CDK2 and PCNA in LMS were significantly higher than those in UL and BLM, P<0.05.The protein expression of cyclin E, CDK2 and PCNA in BLM were also higher than that in UL, but no statistical significance was found between UL and BLM, P>0.05. But no significant difference was found in CL, BL and ML, P>0.05.2. The mRNA expression of cyclin E, CDK2 and PCNA in UL were significantly higher than that in M and show a significant difference, P<0.05.3. There was positive correlation of cyclin E and cdk2 in USMTs, r=0.517,P<0.05. The expression of cyclin E, CDK2 and PCNA significantly increased from UL, BLM to LMS, and positive correlations were found between cyclin E and PCNA, CDK2 and PCNA, r=0.623, P<0.05; r=0.461, P<0.05.Conclusion:An abnormal elevated expression of cyclin E and cdk2 made the regulatory unbalance of cell cycle and induces excess proliferation of uterine smooth muscle cells. These may promote the growth and development of uterine leiomyoma and even progress malignant LMS. The regulatory unbalance of cyclin-CDK-CKI may be involved in the pathogenesis and development of uterine smooth muscle tumors (USMTs).