Differential Expression of Glu-Tubulin in Basal-Like Phenotype Carcinoma of the Mammary Gland

High levels of tubulin expression have been described in a variety of human malignant tumors, and glu-tubulin, in which the C-terminal tyrosine of α-tubulin is removed by tubulin carboxypeptidase. Over-expression has been reported in the malignant tumors of the mammary gland and correlated with poor prognosis immunohistochemically. Furthermore, Nielsen et al. proposed that the use of a panel of four markers (ER, HER 2, CK 5/6, and EGFR) could accurately identify basal-like phenotype carcinoma (BPC) with widely available standard pathologic tools. In our study, major prognostic factors such as patient age, tumor size, histological grade, axillary lymph node metastasis, vessel invasion, and local recurrence in BPC were not significantly different from non BP carcinoma (NBPC). However, the BPC group showed a higher ratio of distant metastasis than that of the NBPC group. In triple-negative carcinoma (TNC) cases, staining for glu-tubulin was observed in 46 cases (63.8%), which consisted of 42 of the 58 BPC patients (72.4%) and 4 of the 14 NBPC patients (28.6%). A significant association was found between the expression of glu-tubulin and BPC, but not NBPC. It seems that our findings also agree with the observation that BPC exhibits aggressive biological behavior and increases the content of glu-tubulin, which plays a greater role in migration and invasion.