Different Expression Of Cell Cycle Related Genes And Clinico-Pathological Significance Of DNA Ploidy Detecion In Breast Neoplasm

Objectives:To investigate the differentially expression of cell-cycle related genes and the clinico-pathological significance of DEK overexpression and DNA ploidy analysis in breast cancer.Materials and Methods:Total 144 cases of paraffin embedded breast lesion blocks, including 93 cases of breast cancers,31 cases of ductal carcinoma in situ (DCIS),20 cases of normal breast tissues, were selected from Department of Pathology, Yanbian Tumor Hospital and Samsung Medical Center (South Korea) in the period of 2001-2006. Additionally, the fresh tissues including 8 of breast cancers, 1 of fibroadenoma,1 of breast adenosis and 2 of normal breast specimens, which were provided by Yanbian Tumor Hospital, were also involved in this study. Gene expression (copy number) was detected by SNP gene chip, and DEK protein expression and DNA ploidy analysis were performed by immunohistochemistry and flow cytometry, respectively.Results:SNP gene chip results showed that the copy number of DEK, CDK2, CyclinD1, CDK4, P27, E2F1, E2F3, and PLK1 were up-regulated, while Ezrin, P21, P16, TP53, CDC25A, RBI, CDK1 were down-regulated. DNA ploidy analysis showed that all 5 of normal tissues,1 of fibroadenoma and 1 of breast adenosis were DNA diploidy, however,39.4%(13/33) of invasive breast carcinoma and 16.7%(2/12) of DCIS showed DNA aneuploidy, and the percent of DNA aneuploidy significantly higher in lymph node metastastic breast cancers (57.1%,8/14) than in non-metastatic breast cancers (26.3%,5/19) (P<0.05). Immunohistochemical staining showed that DEK protein was located in the nucleus. The positive rate of DEK protein expression were 94.6%in breast carcinoma,87.1%in DCIS,20.0%in normal breast tissues, respectively (P<0.05), and the strongly positive rate of DEK protein were 74.2%in breast carcinoma,51.6%in DCIS, and 0%in normal breast tissues, respectively (P<0.01). Also, we found that the overexpression of DEK protein had no correlation with the expression of ER, PR and the pathological grading. The positive rate of DEK were 85.7%(36/42) and 79.5%(31/39) in breast carcinoma with ER, PR-negative, 64.7%(33/51) and 70.4%(38/54) with ER, PR-positive (P>0.05). Additionally, the strongly positive rate were 84.2%(16/19),73.8%(31/42) and 68.8%(22/32) in the gradel,2 and 3, respectively (P>0.05).Conclusions:A variety of cell cycle related genes and proteins involved in the pathogenesis of breast cancer. The detection of DEK protein expression played an important role for early diagnosis of breast cancer, and DNA aneuploidy had closely relationship with the prognosis of breast cancer.