Expression of centrosomal tubulins associated with DNA ploidy in breast premalignant lesions and carcinoma

Abstract

The centrosome plays an essential role in chromosomal segregation during cell division. Centrosome dysfunction might lead to aneuploidy and chromosomal instability. Invasive breast tumors with centrosome amplification often show aneuploidy.Flow cytometry (FCM) was used to examine the aneuploidy rate in 30 cases of each of the following seven tissue types: normal breast tissue, usual ductal hyperplasia, atypical ductal hyperplasia, low-grade ductal carcinoma in situ, high-grade ductal carcinoma in situ, low-grade invasive ductal carcinoma, and high-grade invasive ductal carcinoma. Centrosomal α, γ-tubulin expression was examined by FCM immunofluorescence and compared between diploid and aneuploid cells.The aneuploidy rate was 0, 6.7%, 26.7%, 30.0%, 46.7%, 56.7%, and 86.7%, respectively, in the seven tissue types. The percentage of cells expressing α- and γ-tubulins was significantly different between the seven groups, and the positive rate of α- and γ-tubulin expression in ADH, DCIS and IDC was higher than that in NBT and UDH. The percentage of cells expressing α- and γ-tubulins in the diploid state was significantly lower than that in the aneuploid state.Expression of centrosomal α- and γ-tubulins seems to be associated with DNA ploidy in breast premalignant lesions and carcinoma during the progression of breast cancer.