Noriko Abe

Upregulated Annexin A1 promotes cellular invasion in triple-negative breast cancer

Annexin A1 (ANXA1) is a calcium-dependent phospholipid-linked protein, involved in anti-inflammatory effects, regulation of cellular differentiation, proliferation and apoptosis. While many studies have investigated the ANXA1 expression in various tumor types, the role of ANXA1 is not fully understood. Therefore, in the present study, we evaluated the ANXA1 expression in 211 breast cancer patients and compared the levels with clinicopathological factors. ANXA1 was positively expressed in 31 (14.7%) of the 211 cases in our cohort, and these positive cases were associated with triple-negative breast cancer (TNBC) (P=0.007) and venous invasion (P=0.028). The in vitro cell experiment found that the MDA-MB-231 cell line, which is a TNBC cell line, highly expressed ANXA1. Using this cell line, the functional role of ANXA1 in breast cancer was revealed and the knockdown of ANXA1 by specific siRNA demonstrated a significant reduction in cellular invasion. Further experiments indicated that ANXA1 was induced by hypoxia with hypoxia-inducible factor-1α induction. These results suggested that ANXA1, which enhanced breast cancer invasion and metastasis under hypoxia, were significantly associated with the worst patient outcome. This is particularly noted in TNBC, the group of breast cancer with the worst outcome for which new therapeutic implications are required.

Myeloid-derived suppressor cells are increased and correlated with type 2 immune responses, malnutrition, inflammation, and poor prognosis in patients with breast cancer

Myeloid-derived suppressor cells (MDSCs) have been identified in the majority of patients and experimental mice with tumors by their suppression of T cell activation. MDSCs have also been reported to be associated with chronic inflammation. In advanced cancer, the T helper (Th) cell balance tends to shift from Th1 to Th2 predominance, and immune function, including cell-mediated immunity, is impaired by cytokines produced by Th2 cells. The present study examined the correlations between MDSC levels and inflammation, immune suppression, malnutrition, and poor prognosis in 155 patients with breast cancer. The levels of MDSCs in preoperative patients and in patients with recurrent breast cancer were significantly higher compared with postoperative patients, patients with recurrent breast cancer who received chemotherapy and healthy volunteers. The MDSC levels of preoperative patients were significantly positively correlated with interleukin (IL)-6 production by peripheral blood mononuclear cells (PBMCs), the neutrophil/lymphocyte ratio and C-reactive protein, and were negatively correlated with the production of interferon-γ and IL-12, serum concentration of rapid turnover protein, and the stimulation index. These patients were divided into two groups based on the levels of MDSCs. In preoperative patients with MDSC levels >1.0% of total PBMCs, the overall survival of patients with stage IV disease was significantly shorter compared with other disease stages, and was also significantly shorter compared with patients with MDSC levels <1.0% of total PBMCs. Thus, the MDSC levels of preoperative patients may function as a good prognostic indicator, particularly in patients with advanced breast cancer.

Immunogenic tumor cell death induced by chemotherapyin patients with breast cancer and esophageal squamous cell carcinoma

It has been reported that chemo-radiotherapy can induce immunogenic tumor cell death (ICD), which triggers T-cell immunity mainly mediated by high-mobility group box 1 protein (HMGB1) and calreticulin. However, there is still limited information to support this theory relating to chemotherapy alone. In the present study, the expression of HMGB1 and calreticulin was evaluated by immunohistochemistry in pre-treatment biopsy specimens and surgically resected specimens, which were obtained from patients with breast cancer (n=52) and esophageal squamous cell carcinoma (ESCC) (n=8) who had been treated with neoadjuvant chemotherapy (NAC). We also analyzed HMGB1 and calreticulin expression in breast cancer cell lines treated with chemotherapeutic drugs. As a result, both HMGB1 and calreticulin expression levels were significantly upregulated after NAC in both breast cancer and ESCC tissues. However, no significant correlation was observed between HMGB1 expression and pathological response after NAC or between HMGB1 expression and patient survival. Furthermore, although overall survival in the high infiltration group of CD8-positive T cells was significantly superior to that in the low infiltration group in breast cancer patients, there were no correlations between the number of CD8-positive T cells and HMGB1 or calreticulin expression levels. In addition, chemotherapeutic drugs induced upregulation of HMGB1 and calreticulin in all tested cell lines. Our findings indicate that chemotherapy alone can significantly induce ICD regardless of the degree of pathological response after chemotherapy.

Clinicopathological significance of lymphangiogenesis detected by immunohistochemistry using D2-40 monoclonal antibody in breast cancer.

To elucidate the association between the lymphangiogenesis and clinicopathological factors including the survival in breast cancer, 91 Japanese patients with breast cancer were investigated.　The lymphangiogenesis was evaluated by the count of lymph vessel density (LVD) with immunohistochemical method using D2-40 monoclonal antibody, a specific marker for lymphatic endothelial cells.D2-40-positive lymph vessels were detected in 87 of 91 cases, and were mainly distributed in the peritumoral lesions or around the tumor edge.　There was a significant difference in disease-free survival (DFS) and overall survival (OS) between patients with high LVD and with low LVD (p=0.02, 0.01, respectively, log-rank test).　In addition, LVD significantly correlated with the following clinicopathological factors: menopausal status (p<0.01), tumor size (p<0.01), lymph-node status (p=0.01) lymphatic vessel invasion (LVI) (p<0.01), blood vessel invasion (BVI) (p=0.03) and estrogen receptor status (ER) (p=0.02).Those data suggest that D2-40 monoclonal antibody is a useful marker for evaluating the LVD and its evaluation is helpful to predict the survival in breast cancer.

Pathological aspects of the intraductal spread of breast cancer

The intraductal spread of breast cancer is a major cause of local recurrence following breast-conserving therapy. To properly understand this pathology, three-dimensional (3D) cancer localization within the mammary ductal–lobular system (MDLS) is necessary. To this end we generated computer-assisted 3D reconstructions of all MDLSs using 2-mm-thick serial sections of surgically resected specimens. We then analyzed the characteristics of intraductal spread of breast cancer. In our study of quadrantectomy specimens from patients with primary invasive breast carcinoma, the intraductal spread of breast cancer was found to be continuous from the invasive tumor and spreading along the mammary glandular tree. The pattern is categorized into three types: the central type, the peripheral type, and the extensive type. The central type was found to be most common. A 3D analysis of total mastectomy specimen from a patient with primary non-invasive breast carcinoma revealed regional intraductal spread extending within and filling a single MDLS. The analysis also revealed the presence of ductal anastomoses connecting adjacent MDLSs. These ductal anastomoses were found to be an anatomical risk factor for extensive intraductal spread of breast cancer across multiple MDLSs. To minimize residual non-invasive components of breast carcinoma in the conserved breast, which is strongly associated with the outcome of local control of breast-conserving therapy, it is necessary to determine the optimum surgical margins in a flexible, patient-specific manner. This determination should be based on anatomical characteristics of the MDLS, such as those identified in the present study.

Decreased expression of CADM1 and CADM4 are associated with advanced stage breast cancer

Cell adhesion molecule (CADM) genes encode immunoglobulin superfamily molecules, which are involved in cell-cell adhesion in a number of human epithelia. Through the maintenance of epithelia, CADM genes protect against malignant conversion and metastasis. Whilst numerous in vitro studies have investigated the molecular characteristics of CADM1 and CADM4 and in vivo studies have investigated CADM1 and CADM4 expression in a number of tumor types, the roles of CADM1 and CADM4 have yet to be elucidated. Therefore, in the present study, CADM1 and CADM4 expression levels were evaluated using immunohistochemistry staining in 208 patients with breast cancer and compared with clinicopathological factors. CADM1 and CADM4 expression levels were negative in 160 (76.9%) and 166 (79.8%) of the 208 cases, respectively. The lack of expression in these cases was associated with advanced tumor stage, suggesting that inactivation of CADM1 and CADM4 promotes breast cancer development. The prognostic role of CADM1 and CADM4 in breast cancer was also evaluated and the expression of CADM1 and CADM4 were not associated with cancer-specific survival or overall survival rate in the cohort of patients in the present study. Whilst these results suggested that CADM1 and CADM4 possess tumor suppressive roles, further functional experiments are required to address the important mechanisms involving CADM1 and CADM4.

IL-17 and VEGF are increased and correlated to systemic inflammation, immune suppression, and malnutrition in patients with breast cancer:

Relationships between inflammation and innate immunity in cancer are widely accepted today; however, the precise cell mechanisms mediating these relationships have not yet been elucidated. Interleukin (IL)-17 is a proinflammatory cytokine that has been reported to induce inflammation in patients with autoimmune diseases. Myeloid-derived suppressor cells (MDSC) may contribute to the negative regulation of immune responses during cancer and inflammation. Vascular endothelial growth factor (VEGF) is reported to have multiple biological actions including increasing vascular permeability, neovascularization, and possible inhibition of immune function in malignant diseases. This study investigated the status of systemic inflammation and immune suppression associated with IL-17 and VEGF in patients with breast cancer. IL-17 production and the serum levels of VEGF were also increased in advanced stages of the disease. The production of IL-12, which induces Th1 cells, and the stimulation index (SI), which is a marker of cell-mediated immune function, were both shown to decrease along with disease advancement. Also, the production of IL-17 and the VEGF levels were both positively correlated with the levels of MDSC, the neutrophil-to-lymphocyte ratio (NLR), and C-reactive protein (CRP), and were inversely correlated with IL-12 production and the SI. Nutritional markers, including prealbumin (PA), transferrin (TF), and retinol-binding protein (RBP), were also shown to be significantly lower in patients with high production of IL-17 or high levels of VEGF. These data clearly showed that IL-17 and VEGF, whose levels correlated with each other and with those of MDSC, were significantly associated with disease advancement, systemic inflammation, suppression of cell-mediated immunity including Th1 induction, and malnutrition.