The Association Study Of Centrosome-related Kinases-Nek2 In Breast Precancerous & Early Breast Cancer

Objectives: To investigate the Nek2 protein expression and the Nek2 DNA copiesamplification among four groups, which are primary invasive ductal carcinoma (IDC),ductal carcinoma in situ (DCIS), precancerosis (severe ductus epithelium atypicalhyperplasia and severe papillomatosis, pre-Ca) and normal breast tissue (N),especially in precancerous lesion of breast and ductal carcinoma in situ, and withpreviously studies try to find the relationship between Nek2 and centrosome, tofurther demonstrate the role of them in oncogenesis and the feasibility of them aspotential targets for early diagnosis and gene therapy of breast cancer. Methods: 20cases of normal breast tissue, 20 cases of precancerous lesion, 20 cases of ductalcarcinoma in situ and 20 cases of infiltrative ductal carcinoma were analyzed byimmunohistochemistry and real time quantitative PCR. The correlation between themhad been detected and with the previous researches of centrosome the relationshipbetween Nek2 and centrosome had been analyzed, too. Results: The positiveexpression of Nek2 is located in the nucleus and cytoplasm, which is observed asyellow-brown staining. There is significant difference in the expression of Nek2protein among groups to be detected (x~2=25.030, P=0.000). The Nek2proteinexpression in IDC cases is higher than that in normal group (P=0.000) and pre-Cagroup (P=0.033), the Nek2 protein in DCIS cases is higher than that in normal group (P=0.000) and pre-Ca group (P=0.002), the Nek2 expression in pre-Ca group ishigher than that in normal group(P=0.033), and there is no statistically significantdifference between the Nek2 expression in IDC and DCIS groups(P=0.738). There issignificant difference in the copy numbers of Nek2 among groups to bedetected(F=28.735, p=0.000). The DNA amplification of Nek2 in IDC cases is higherthan that in normal group (P=0.000) and pre-Ca group(P=0.027); the amplificationcopies in DCIS cases is higher than that in normal group (P=0.000) and pre-Ca group(P=0.000), and there is no statistically significant difference between theamplification copies in IDC and DCIS groups (P=0.405); the copy number in pre-Cagroup is higher than that in normal group (P=0.000).The Nek2 positive proteinexpression and DNA amplification copies present a positive correlation (r=0.887,P＜0.01) among 4 groups. Conclusions: 1. The expression of Nek2 protein could bedetected by immunohistochemistry to suppose the development of tumor. 2. In theprogression of oncogenesis, the tendency ofNek2 gene amplification is similar withthe Nek2 protein expression. The gene amplification may lead to protein overexpression. 3. The changes of Nek2 and centrosome present a positive correlation.Nek2 changes were supposed to lead to premature centrosome splitting, which causethe tumorigenesis.