Abstract Objective To study the angiopoietin (Ang  2) in breast cancer tissue and vascular endothelial growth factor (VEGF) expression and clinical significance. Immunohistochemical SABC method detected 85 cases of breast cancer and 42 cases of breast fibroadenoma tissue Ang  2 and VEGF expression, and to evaluate the relationship between the two indicators of breast cancer clinicopathological factors. Breast cancer tissue Ang  positive rate (68.24%, 58/85) was significantly higher than that of breast adenoma (7.14%, 3/42) (P <0.0001), breast cancer tissue VEGF positive rate (57.65% 49/85) was significantly higher than that of breast adenoma (4.76%, 2/42) (P <0.0001). Ang  2 and VEGF expression and patient age and tumor size was no significant relationship (P> 0.05). III of IV breast cancer and lymph node metastasis group VEGF positive expression rate was significantly higher than I, Ⅱ breast cancer and lymph node metastasis group (P <0.0001). Ⅲ, Ⅳ stage breast cancer Ang  2 expression positive rate Ⅰ, Ⅱ stage breast cancer group (P = 0.015). Ang  2 positive lymph node metastasis group was significantly higher than the lymph node metastasis group (P <0.0001). Ang  2 and VEGF expression index correlation (P <0.05). Conclusion breast cancer tissue Ang  2 and VEGF expression abnormalities, associated with the prognosis of breast cancer.

Key words breast angiopoietin-vascular endothelial growth factor immunohistochemical methods

    The angiopoietin (angiopoietin, Ang) and vascular endothelial growth factor (vascular endothelial growth factor, VEGF) to generate a promoting factor known role in the endothelial cells of blood vessels, plays an important role in tumor angiogenesis and development The role of [1]. By immunohistochemical detection Ang  2 and VEGF expression in breast cancer, and to evaluate the relationship between the two factors with clinicopathological features.

    1 Data and methods

    1.1 Clinical data

    Collected in our hospital in September 2004 to December 2006 surgery, complete data of breast cancer, 85 cases, and in all cases no preoperative radiotherapy and chemotherapy. Patients were women, aged 32 to 74 years, with an average age of 50.80 years old, with a median age of 51 years old. Axillary lymph node metastasis were 48 cases and 37 cases without lymph node metastasis; clinical stage Ⅰ 18 cases, 51 cases of stage II, 15 stage Ⅲ, Ⅳ stage 1 cases. 42 cases of breast fibroadenoma were compared to surgical treatment of cases.

    1.2 Reagents

    Rabbit anti-Ang  2 and VEGF polyclonal antibody and SABC immunohistochemistry kit were purchased from Wuhan Boster Biological Co., Ltd., DAB chromogenic reagent purchased from Beijing Zhongshan Golden Bridge Biotechnology Co., Ltd..

    1.3 Methods

    Archive wax block to collect appropriate cases, line 5μm thick serial sections, take a HE staining and the remaining rows immunohistochemistry SABC method of dyeing. The steps in strict accordance with the kit instructions. Positive piece of each experiment are provided as a positive control, negative control antibody was replaced with PBS.

    1.4 Results judge

    Cytoplasm brownish yellow-positive cells. 10 high power field (× 400), the average number of positive cells in the light microscope count ≥ 10% the judge positive cases, less than 10% of the negative cases.

    1.5 statistical methods

    The software line statistical analysis of application SAS8.0 χ2 test, test level α = 0.05.

    2 Results

    2.1 Ang  2 and VEGF expression in breast cancer tissue and fibroadenoma

    Breast fibroadenoma and breast tissue Ang  2 positive rate was 7.14% (3/42) and 68.24% (58/85), the difference was statistically significant (χ2 = 42.0313, P <0.0001). Breast fibroadenoma and breast tissue VEGF positive rate was 4.76% (2/42) and 57.65% (49/85), the difference was statistically significant (χ2 = 32.7157, P <0.0001).

    2.2 Ang  2 and VEGF expression in breast cancer and breast cancer biology characteristics

    Table 1.

    2.3 Ang  2 and VEGF expression in breast cancer tissue.

    Ang  2 and VEGF expression were positive in 45 cases, Ang  2 and VEGF expression in 23 cases of negative Ang  2 positive expression and VEGF expression in 13 cases of negative, Ang  2 negative expression and VEGF expression in positive cases. The chi-square test differences was statistically significant (χ2 = 29.3883, P <0.0001).

    3 Discussion

    Solid tumor growth, invasion and metastasis without neovascularization, tumor angiogenesis exist not only for tumor growth and provide nutrients away metabolites, to provide a channel for the invasion and metastasis of tumor cells [2]. Angiopoietin (Ang) and vascular endothelial growth factor (VEGF) and tumor angiogenesis is closely related to the regulation of the formation of tumor blood vessels by a variety of factors.

    The angiopoietin important angiogenesis regulatory factors discovered in recent years, his family members Ang  1 and Ang  2 common receptor Tie  2 (tyrosine kinase receptor  2). Ang  1 to promote vascular endothelial cell sprouting promote vascular remodeling, mature, and to maintain the integrity of the blood vessels, the role of a stabilizing blood vessels. Ang  2 functions mainly through competitive inhibition of Ang  1 receptors Tie  combined vascular endothelial cells with surrounding support cells dissociate to form unstable vascular leakage, thereby contributing to tumor blood vessels Reconstruction and form, and provide a channel for the invasion and metastasis of tumor cells. Ang  1, Ang  2 and tumor blood vessel growth, the relationship between erosion closer [3].

    Vascular endothelial cell growth factor is another important angiogenic factors, it is a high degree of specificity of the vascular endothelial cells have mitogen a strong promoting separatism and chemokines role of vascular endothelial cells, can specifically stimulate endothelial cell proliferation, but also has to promote the role of vascular permeability, vascular endothelial cell migration and tumor metastasis in Table 1 Ang  2 and VEGF expression in breast cancer and breast cancer biological characteristics of the relationship matrix [4].

    The study found that breast cancer tissue Ang  2 and VEGF were significantly higher than in breast fibroadenomas (P <0.0001). By Caine [5] Ang  2 and VEGF expression levels in the plasma of patients with breast cancer increased significantly, Obermair [6] found that breast cancer VEGF expression was significantly higher than in normal breast tissue and fibroadenoma, Dong-ling [7] reported that breast tissue Ang  2 expression was significantly higher than in normal breast stromal tissue and breast fibroid tissue. Neovascularization activity of benign and malignant breast lesions have significant differences, suggesting that Ang  2 and VEGF and breast lesions, benign and malignant, may become one of the indicators of the biological behavior of breast tumors in clinical judgment.

    Sfiligoi [8] found that high levels of Ang  2 expression in breast cancer-prone axillary lymph node metastasis and prognostic significance. Wang et al [9] Ang  2 expression TNM staging, lymph node metastasis and distant metastasis was significantly associated. Gasparini et al [10] reported that tumor tissue abnormal expression of VEGF and prognosis of breast cancer is closely related. Tsutsui et al [11] reported that Ang  2 and VEGF positive expression in breast cancer patients, the disease-free survival time was significantly shortened. Our results show Ⅲ, Ⅳ stage breast cancer group Ang  2 and VEGF positive expression rate was significantly higher than Ⅰ, Ⅱ breast cancer group, lymph node metastasis positive group Ang  2 and VEGF positive rate was significantly higher than the lymph node negative group prompt cancer cells by generating Ang  2 and VEGF promote angiogenesis and make it easy to complete lymph node metastasis, prognostic significance.

    Our experiments found that the expression of Ang  2 and VEGF indicators were significantly correlated (P <0.05), consistent with the results of Tsutsui et al [11]. When the existence of the VEGF, Ang  2 could be antagonized by Ang  1 to promote the role of vascular structure and stability to eliminate the restrictions of vascular basement membrane and peritubular cells of blood vessel formation and increased endothelial cell VEGF sensitivity, beneficial vascular sprouting and growth . When the lack of the VEGF, Ang-2 inhibition Ang  1 favor regression of blood vessels [2,12].

    Ang  2 and VEGF expression in breast cancer tissue detected simultaneously select multiple targets antagonize tumor angiogenesis, treatment and prognosis of breast cancer is important. Currently, anti-VEGF antibody (bevacizumab) has achieved a remarkable efficacy in the treatment of colorectal metastatic cancer, cancer anti-angiogenic therapy made important progress, the drug approved by the U.S. Food and Drug Administration (FDA) approved for colorectal treatment of metastatic carcinoma [13]. Oliner et al [14] Ang  2 antibody treatment of tumor-bearing mice and found that the tumor vascular endothelial cell proliferation was inhibited tumor also was significantly reduced. Ang  2 mainly in tumor tissue and adult female reproductive system, targeting systemic side effects, there is a good prospect.