Mingli Sun

Activation of STAT3 is involved in malignancy mediated by CXCL12-CXCR4 signaling in human breast cancer

The chemokine receptor CXCR4 and signal transducer and activator of transcription 3 (STAT3) play an important role in breast cancer malignancy and metastasis. However, it remains unknown whether STAT3 can be activated by CXCR4 in human breast cancer. The expression levels of CXCR4, STAT3 and p-STAT3 in 208 breast cancer tissues and 26 tumor-adjacent tissues were examined by immunohistochemistry. Flow cytometry, western blot analysis and immunoprecipitation were used to study activation of STAT3 by CXCL12-CXCR4 signaling in human breast cancer cell lines. The expression levels of CXCR4, STAT3 and p-STAT3 were higher in the breast cancer samples than these levels in the tumor-adjacent samples. The combined expression of CXCR4 and p-STAT3 was correlated with TNM stage, tumor size, lymph node metastasis and histological grade of breast cancer. In the breast cancer cells, CXCL12 treatment increased the expression of p-STAT3. The CXCR4 antagonist AMD3100 and the Janus kinase 2 (JAK2) antagonist AG490 inhibited the CXCL12-induced increase in the phosphorylation of STAT3. Furthermore, CXCL12 promoted direct binding of JAK2 to CXCR4. Our findings suggest that activation of the JAK2/STAT3 pathway via CXCL12-CXCR4 signaling plays an important role in breast cancer malignancy and metastasis. Targeting the CXCL12-CXCR4/JAK2/STAT3 signaling pathway may be a potential therapeutic strategy for the treatment of breast cancer.

DNA methyltransferase 1/3a overexpression in sporadic breast cancer is associated with reduced expression of estrogen receptor-alpha/breast cancer susceptibility gene 1 and poor prognosis.

DNA methyltransferases (DNMTs), including DNMT1, 3a, and 3b, play an important role in the progression of many malignant tumors. However, it remains unclear whether expression of DNMTs is associated with the development of breast cancer. This study aimed to explore the clinical significance of DNMT proteins in sporadic breast cancer. We investigated the expression of DNMT1, 3a, and 3b in 256 breast cancer and 36 breast fibroadenoma, using immunohistochemistry. The expression of DNMT1 and 3a was significantly higher in breast cancer than in fibroadenoma. In breast cancer, the expression of DNMT1 was significantly correlated with lymph node metastasis (P = 0.020), and the expression of DNMT3a and 3b was significantly correlated with advanced clinical stages (P = 0.046 and 0.012, respectively). Overexpression of DNMT1/3a was correlated with promoter hypermethylation and reduced expression of ERα and BRCA1. The expression levels of DNMT1 or DNMT3a were associated with a significantly shorter DFS or OS in a subgroup of breast cancer patients (patients with the age ≤50 years old, ERα‐negative status, or HER2‐postive status). The expression of DNMT1 or a combined expression of DNMT1 and 3a was associated with poor prognosis in patients who received chemotherapy and endocrine therapy, but not in patients who received chemotherapy alone. These findings suggest that DNMT1 and 3a may be involved in the progression and prognosis of sporadic breast cancer.

MiR-487a Promotes TGF-β1-induced EMT, the Migration and Invasion of Breast Cancer Cells by Directly Targeting MAGI2.

Tumor metastasis is a complex and multistep process and its exact molecular mechanisms remain unclear. We attempted to find novel microRNAs (miRNAs) contributing to the migration and invasion of breast cancer cells. In this study, we found that the expression of miR-487a was higher in MDA-MB-231breast cancer cells with high metastasis ability than MCF-7 breast cancer cells with low metastasis ability and the treatment with transforming growth factor β1 (TGF-β1) significantly increased the expression of miR-487a in MCF-7 and MDA-MB-231 breast cancer cells. Subsequently, we found that the transfection of miR-487a inhibitor significantly decreased the expression of vimentin, a mesenchymal marker, while increased the expression of E-cadherin, an epithelial marker, in both MCF-7 cells and MDA-MB-231 cells. Also, the inactivation of miR-487a inhibited the migration and invasion of breast cancer cells. Furthermore, our findings demonstrated that miR-487a directly targeted the MAGI2 involved in the stability of PTEN. The down-regulation of miR-487a increased the expression of p-PTEN and PTEN, and reduced the expression of p-AKT in both cell lines. In addition, the results showed that NF-kappaB (p65) significantly increased the miR-487a promoter activity and expression, and TGF-β1 induced the increased miR-487a promoter activity via p65 in MCF-7 cells and MDA-MB-231 cells. Moreover, we further confirmed the expression of miR-487a was positively correlated with the lymph nodes metastasis and negatively correlated with the expression of MAGI2 in human breast cancer tissues. Overall, our results suggested that miR-487a could promote the TGF-β1-induced EMT, the migration and invasion of breast cancer cells by directly targeting MAGI2.

Combined expression of ezrin and E-cadherin is associated with lymph node metastasis and poor prognosis in breast cancer

Ezrin and E-cadherin have been known to play a role in tumor metastasis. However, the association between the expression of ezrin and E-cadherin in breast cancer patients remains unclear. In the present study, we investigated the expression of ezrin and E-cadherin in 275 breast cancer and 80 control patients with benign hyperplasia, using tissue microarray-based immunohistochemistry (IHC). Ezrin expression was higher, while that of E-cadherin was lower in breast cancer than in control samples. Ezrin expression was negatively correlated with E-cadherin expression in a subpopulation of breast cancer patients with a high expression of ezrin [ezrin(high)] and a low expression of E-cadherin [E-cad(low)]. The cytoplasmic expression of E-cadherin [E-cad(c)] occurred significantly more frequently in ezrin(high) breast cancer than in ezrin(low) breast cancer. The expression level of ezrin was significantly higher in breast cancer with E-cad(c) than that with a membrane expression of E-cadherin [E-cad(m)]. Ezrin(high) or E-cad(low) expression was more associated with lymph node metastasis, and shorter overall survival (OS) and disease-free survival (DFS) in breast cancer patients. E-cad(c) was more associated with lymph node metastasis and shorter OS and DFS compared with E-cad(m). The combined expression of ezrin(high) and E-cad(low) or ezrin(high) and ezrin(c) was more associated with lymph node metastasis and poor prognosis. In addition, the multivariate Cox regression analysis revealed that lymph node metastasis and ezrin(high) expression were independent prognostic factors for shorter OS and DFS in breast cancer patients. The results of the present study suggested that ezrin promotes breast cancer metastasis via the regulation of E-cadherin expression.

Ano1/TMEM16A Overexpression Is Associated with Good Prognosis in PR-Positive or HER2-Negative Breast Cancer Patients following Tamoxifen Treatment.

The calcium-activated chloride channel Ano1 (TMEM16A) is overexpressed in many tumors. Although Ano1 overexpression is found in breast cancer due to 11q13 amplification, it remains unclear whether signaling pathways are involved in Ano1 overexpression during breast cancer tumorigenesis in vivo. Estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) have been known to contribute to breast cancer progression. It is unclear whether Ano1 is associated with clinical outcomes in breast cancer patients with different ER, PR and HER2 status. In the present study, we investigated the Ano1 expression in 431 patients with invasive ductal breast carcinoma and 46 patients with fibroadenoma, using immunohistochemistry, and analyzed the association between Ano1 expression and clinical characteristics and outcomes of breast cancer patients with different ER, PR, and HER2 status. Ano1 was overexpressed in breast cancer compared with fibroadenoma. Ano1 was significantly more associated with breast cancer with the lower clinical stage (stage I or II), or triple-negative status. Mostly importantly, Ano1 overexpression was associated with good prognosis in patients with the PR-positive or HER2-negative status, and in patients following tamoxifen treatment. Multivariate Cox regression analysis showed that Ano1 overexpression was a prognostic factor for longer overall survival in PR-positive or HER2-negative patients, and a predictive factor for longer overall survival in patients following tamoxifen treatment. Our findings suggest that Ano1 may be a potential marker for good prognosis in PR-positive or HER2-negative patients following tamoxifen treatment. The PR and HER2 status defines a subtype of breast cancer in which Ano1 overexpression is associated with good prognosis following tamoxifen treatment.

Suppression of 2,4-dinitrochlorobenzene-induced atopic dermatitis by extract of Bacillus Calmette-Guerin

Bacillus Calmette-Guerin extract (BCGE) has been proven to be clinically effective for anaphylactic disease, infectious diseases and cancer. In this study, we investigated the effect of the intramuscular application of BCGE on 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD). We established an AD model in BALB/c mice by repeated local exposure of DNCB to the ear and dorsal skin. Following intramuscular application of BCGE, the ear thickness, mast cell infiltration, serum total immunoglobulin E (IgE) and histamine level were measured. In addition, levels of interleukin (IL)-4, IL-13, interferon (IFN)-γ and tumor necrosis factor (TNF)-α in the ears were assayed. BCGE reduced AD symptoms based on ear thickness, dermatitis score, histopathological analysis and serum IgE levels. In addition, BCGE inhibited mast cell infiltration into the ear and elevation of serum histamine, increased IFN-γ level and suppressed IL-4, IL-13 and TNF-α levels in the ears. Furthermore, BCGE attenuated the NF-κBp65 expression in the nuclear extract of the ear tissue. Taken together, our results demonstrated that intramuscular application of BCGE exerts beneficial effects on the symptoms of AD suggesting that BCGE may be a candidate for the treatment of AD.

Attenuating effects of omega-3 fatty acids (Omegaven) on irradiation-induced intestinal injury in mice.

Gastrointestinal injury is a major cause of death following exposure to high levels of irradiation, and no effective treatments are currently available. In this study, we examined the effect of omega-3 fatty acids (Omegaven) on intestinal injury of BALB/c mice induced by irradiation. Intravenously administered 3 days prior to irradiation for 7 consecutive days, Omegaven was shown to improve survival, intestinal morphology including villous height, crypt height and mucosal thickness and the intestinal proliferation compared with saline control. Omegaven also normalized the levels of circulating tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), attenuated the increase of diamino oxidase (DAO) activity and malondialdehyde (MDA) level and recovered the decrease of superoxide dismutase (SOD) activity. Meanwhile, Omegaven attenuated the myelosuppression caused by irradiation. In conclusion, our results suggest that Omegaven enhanced the survival of irradiated mice and minimized the effects of radiation on gastrointestinal injury.

Combined expression of aldehyde dehydrogenase 1A1 and β-catenin is associated with lymph node metastasis and poor survival in breast cancer patients following cyclophosphamide treatment

This study investigated the expression of ALDH1A1 and β-catenin in breast cancer patients, and analyzed the correlation of their combined expression with clinicopathological features, chemotherapeutic responses, and prognosis of breast cancer patients. In total 276 human breast cancer tissues and 80 benign hyperplasia tissues were included. The expression of ALDH1A1 and β-catenin was examined using tissue microarray-based immunohistochemistry. ROC curve analysis was performed to determine an optimal cut-off score for the expression of ALDH1A1 and β-catenin, based on the survival status of breast cancer patients. Survival probabilities were estimated by the Kaplan-Meier method. ALDH1A1 expression was higher, but β-catenin showed no significant difference in breast cancer samples compared to controls. Compared with the membrane expression of β-catenin [β-catenin(m)], the cytoplasmic expression of β-catenin [β-catenin(c)] occurred significantly more frequently in breast cancer with the high expression of ALDH1A1 [ALDH1A1(high)] than in breast cancer with the low expression of ALDH1A1 [ALDH1A1(low)] (P=0.014). The expression level of ALDH1A was significantly higher in β-catenin(c) breast cancer than in β-catenin(m) breast cancer (P=0.020). ALDH1A1(high) expression or β-catenin(c) expression alone was associated with lymph node metastasis, and worse clinical outcome in breast cancer patients, especially in patients receiving cyclophosphamide treatment. Combined expression of ALDH1A1(high) and β-catenin(c) was associated with lymph node metastasis, poor outcome, and resistance to cyclophosphamide treatment. β-catenin may regulate ALDH1A1 expression in a subtype of breast cancer with ALDH1A1(high) and β-catenin(c) expression. ALDH1A1(high) and β-catenin

Poly(ADP‑ribose) polymerase‑3 overexpression is associated with poor prognosis in patients with breast cancer following chemotherapy

Double strand breaks induced by genotoxic agents, if inappropriately repaired, will cause cell death or induce cancer. Poly(ADP-ribose) polymerase-3 (PARP-3) serves a role in double strand break repair, and may be involved in tumorigenesis. To the best of our knowledge, the role of PARP-3 in breast cancer has not yet been examined. In the present study, the expression of PARP-3 was investigated in 493 breast cancer samples and 54 tumor-adjacent control samples using tissue-microarray-based immunohistochemistry. PARP-3 expression was higher in breast cancer samples compared with control samples. PARP-3 overexpression was significantly associated with histological grade II–III (P=0.012). In addition, PARP-3 overexpression was significantly associated with shorter disease-free survival (DFS; P=0.027) time and exhibited a tendency toward shorter overall survival (OS; P=0.183) time in patients with breast cancer compared with patients with lower PARP-3 expression, particularly in BRCA1-positive patients (P=0.004 for disease-free survival and P=0.095 for OS). Multivariate Cox regression analysis indicated that PARP-3 was an independent prognostic factor in patients with breast cancer. Furthermore, it was revealed that PARP-3 overexpression was associated with shorter survival time in patients with cyclophosphamide/doxorubicin or epirubicin/5-fluorouracil (CAF/CEF) chemotherapy compared with low PARP-3 expression, but not in patients with CAF/CEF + docetaxel chemotherapy. The present study suggested that PARP-3 may be used as a biomarker for predicting the clinical outcome of patients receiving chemotherapy, and targeting PARP-3 may be a potential therapeutic strategy for the treatment of breast cancer.