Abnormal expression of Nek2 and β-catenin in breast carcinoma: Clinicopathological correlations

Department of Breast Cancer Pathology and Research Laboratory of Tianjin Medical University, China.
Histopathology (Impact Factor: 3.45). 10/2011; 59(4):631-42. DOI: 10.1111/j.1365-2559.2011.03941.x
Source: PubMed


NIMA-related kinase 2 (Nek2) and β-catenin are important centrosome regulatory factors. The aim of this study was to detect the possible disparity in their expression among normal breast tissue, invasive ductal carcinoma (IDC), concomitant ductal carcinoma in situ (DCIS), and pure DCIS, and to explore its correlation with clinicopathological factors.
We used immunohistochemistry to detect protein expression of Nek2 and β-catenin in breast cancer tissues from 60 cases of pure DCIS, 348 cases of IDC and 137 cases of concomitant DCIS with that in normal breast tissues from the same 137 concomitant DCIS patients as controls. As compared with normal tissue, expression of Nek2 and β-catenin in the cytoplasm was significantly increased in IDC and DCIS (P < 0.05), and variation in expression was also observed in different grades of IDC (P < 0.01). Also, cytoplasmic expression of Nek2 and and of β-catenin were correlated with each other in IDC and DCIS (P < 0.01). In addition, they were both related to Ki67 immunoreactivity (P < 0.05). Furthermore, our study also revealed a correlation between their expression and some clinicopathological factors. We found that Nek2 cytoplasmic expression was associated with grade and tumour size (P < 0.01) in IDC, whereas β-catenin cytomembrane expression showed significant variation with grades, TNM stages, lymphoid node status, oestrogen receptor status, and molecular subtype (P < 0.05); a difference in expression was also observed between IDC and DCIS (P < 0.05). Also, β-catenin cytoplasmic expression was associated with TNM stage (P < 0.05). Expression of Nek2 at the mRNA level was detected in 50 pairs of breast cancer specimens and matched normal tissues by reverse transcriptase polymerase chain reaction, and the result showed increased expression in IDC.
This study suggests that abnormal expression of Nek2 and β-catenin might be one of the mechanisms of tumorigenesis, especially of abnormal tumour proliferation. They may represent new potential targets for therapeutic intervention.

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    • "In our current filtering of 1q genes related to survival, CENPF (HR = 1.616; p-value = 4.90E-05) ranked first followed by NEK2 (HR = 1.641; p-value = 0.000163) which demonstrates the reliability of the strategy and the results obtained in the study. Commonality with most of the short-listed genes (CENPF, KIF14, NEK2, CKS1B and ASPM) is their positive association with proliferation marker Ki-67 [26,27,30,45,46], thereby, indicating their possible role in cell cycle related dysregulations and the resultant proliferation of breast cancer cells. However, it has been reported that simultaneous 1q gain/16q loss was related to low Ki-67 level (low proliferation) and high p27 expression of breast cancer cells [17]. "
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