Abstract:
Objective To investigate the expression and significance of β1 integrin, Rac1, and RhoA in invasive micropapillary breast carcinoma (IMPC).
Methods Immunohistochemical staining was performed to detect the expression of β1 integrin, Rac1, and RhoA in 89 patients with IMPC and 90 patients with invasive ductal carcinoma-not otherwise specified (IDC-NOS) who were treated between January 2007 and December 2008 in Tianjin Medical University Cancer Institute and Hospital. The relationship among the three proteins and the expression of β1 integrin, Rac1, and RhoA with clinicopathological features were determined.
Results β1 integrin (78.7%) and Rac1 (76.4%) were highly expressed in patients with IMPC. This expression was significantly higher than that in patients with IDC-NOS (63.3% and 54.4%). Statistical difference was found between the two groups (P < 0.05). Positive rate of RhoA (68.5%) in patients with IMPC was also statistically higher than that in patients with IDC-NOS (44.4%, P=0.001). In patients with IMPC, the expression of β1 integrin and Rac1 was positively associated with lymph node metastasis (P < 0.05), while the expression of β1 integrin was positively correlated with Rac1 expression (P=0.006). Expression of RhoA was positively correlated with lymph node involvement and ER and PR status (P < 0.05). However, no correlation was found between RhoA expression and the expression of β1 integrin and Rac1 (P>0.05).
Conclusion Thus, β1 integrin, Rac1, and RhoA were overexpressed and might play an important role in the high frequency of metastasis in patients with IMPC. These proteins could be considered as biomarkers for the prognosis and new targets for IMPC therapy.