ABSTRACT
Objective To evaluate the expression and clinical significance of cyclin dependent kinase (CDK)-activating kinase (CAK) complex including CDK7, cyclin H and accessory protein menage a trios 1 (MAT1) in estrogen receptor-positive breast cancer.Methods A total of 40 patients with estrogen receptor-positive breast cancer from Department of Galactophore, Baoji Maternal and Child Care Service Centre of Shaanxi Province were investigated in this study.Breast cancer tissues and adjacent normal tissues were obtained from patients undergoing surgery.The mRNA expressions of CDK7, cyclin H and MAT1 in two types of tissues were measured by real-time fluorescent quantitative (qRT)-PCR, and their correlations with clinicopathologic features of patients were analyzed.Results The expressions of CDK7, cyclin H and MAT1 in cancer tissues were 2.54±0.78, 2.21±0.56 and 2.46±0.58, while those in adjacent normal tissues were 1.26±0.30, 1.16±0.42 and 1.17±0.39, and there were significantly differences between different types of tissues (t=9.654, P<0.001;t=9.433, P<0.001;t=11.741, P<0.001).The higher expressions of cyclin H and MAT1 in patients′ cancer tissues had the lower clinical stage, with significant correlations (U=3.17, P=0.01;U=2.53, P=0.01).In addition, the tumors were smaller in patients with higher expression levels of MAT1 (χ2=14.16, P=0.01).Conclusion The expressions of CAK complex CDK7, cyclin H and MAT1 are elevated in estrogen receptor-positive breast cancer patients.Cyclin H and MAT1 are closely associated with clinical grade, and MAT1 is also significantly associated with tumor size.