Youxue Zhang

Association Analysis of IL-17A and IL-17F Polymorphisms in Chinese Han Women with Breast Cancer

Background Research into the etiology of breast cancer has recently focused on the role of the immunity and inflammation. The proinflammatory cytokines IL-17A and IL-17F can mediate inflammation and cancer. To evaluate the influences of IL-17A and IL-17F gene polymorphisms on the risk of sporadic breast cancer, a case-control study was conducted in Chinese Han women. Methodology and Principal Findings We genotyped three single-nucleotide polymorphisms (SNPs) in IL-17A (rs2275913, rs3819025 and rs3748067) and five SNPs in IL-17F (rs7771511, rs9382084, rs12203582, rs1266828 and rs763780) to determine the haplotypes in 491 women with breast cancer and 502 healthy individuals. The genotypes were determined using the SNaPshot technique. The differences in the genotypic distribution between breast cancer patients and healthy controls were analyzed with the Chi-square test for trends. For rs2275913 in IL-17A, the frequency of the AA genotype was higher in patients than controls (P = 0.0016). The clinical features analysis demonstrated significant associations between IL-17 SNPs and tumor protein 53 (P53), progesterone receptor (PR), human epidermal growth factor receptor 2 (Her-2) and triple-negative (ER-/PR-/Her-2-) status. In addition, the haplotype analysis indicated that the frequency of the haplotype Ars2275913Grs3819025Grs3748067, located in the IL-17A linkage disequilibrium (LD) block, was higher in patients than in controls (P = 0.0471 after correction for multiple testing). Conclusions and Significance Our results suggested that SNPs in IL-17A but not IL-17F were associated with the risk of breast cancer. Both IL-17A and IL-17F gene polymorphisms may provide valuable information for predicting the prognosis of breast cancer in Chinese women.

Dysregulated expression of Slug, vimentin, and E-cadherin correlates with poor clinical outcome in patients with basal-like breast cancer

Among the different types of breast cancer, basal‐like breast cancer (BLBC) has an extremely poor prognosis due to its high rate of recurrence and metastasis. The present study aimed to investigate the correlation between the expression of Slug, E‐cadherin, and vimentin, and the clinicopathological characteristics and prognosis of patients with BLBC. We further inferred from these findings whether Slug leads to a poor prognosis in patients with BLBC through epithelial–mesenchymal transition (EMT).

Frequent low expression of chromatin remodeling gene ARID1A in breast cancer and its clinical significance.

BACKGROUND ARID1A gene encodes BAF250a which is a member of the ARID family of DNA-binding proteins and a subunit of human SWI/SNF-related complexes. Low expression of ARID1A has been correlated with specific tumor cell lines or specific pathological types of cancer tissue. The purpose of this study was to investigate the expression of ARID1A in invasive ductal breast carcinomas and to evaluate its clinicopathological characteristics and prognostic value. METHODS ARID1A mRNA expression was evaluated by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) in 40 pairs of fresh frozen breast cancer and normal breast samples. BAF250a expression was evaluated by immunohistochemistry in 112 paraffin-embedded surgical specimens of invasive breast cancers and 20 cases of matched normal breast tissues. We further analyzed the clinicopathological characteristics of ARID1A expression. Overall survival time was assessed by the Kaplan-Meier method and Cox regression model. RESULTS ARID1A mRNA expression was lower in breast cancer tissue than in corresponding normal tissue (P<0.001), and this decreased expression level was markedly associated with factors such as larger tumor size (P=0.038), higher stage (P=0.016), ER(-) (P=0.038), higher Ki-67 (P=0.025), P53 mutation (P=0.018) and ER(-)/PR(-)/Her-2(-) molecular subtype (P=0.044). With immunohistochemical staining, we showed that low BAF250a expression existed in 56% (63/112) of the breast cancers tissues. Low BAF250a expression was significantly associated with tumor stage (P=0.021), P53 (P=0.018), Ki-67 (P=0.031) and ER(-)/PR(-)/Her-2(-) molecular subtype (P=0.044). Low ARID1A expression was a predictor, not an independent, of overall survival. CONCLUSION These data suggest that low ARID1A expression is frequent in breast cancers, and we need to investigate further the role of ARID1A and SWI/SNF complexes in breast tumorigenesis, especially in triple-negative breast cancer.

Unique clinicopathological features of metaplastic breast carcinoma compared with invasive ductal carcinoma and poor prognostic indicators

BackgroundMetaplastic breast carcinoma is a rare aggressive malignant neoplasm. The purposes of this study are to review the pathologic features and clinical outcomes of metaplastic breast carcinoma compared to invasive ductal carcinoma and to evaluate the prognosis of metaplastic breast carcinoma.MethodsThe cases of 55 patients with metaplastic breast carcinomapresenting between 1991 and 2006 were analyzed and compared to the cases of 767 age-matched patients with invasive ductal carcinoma from the same time period.ResultsThe group of patients with metaplastic breast carcinoma presented with a larger tumor size, lower lymph node involvement, higher percentage of triple-negative (estrogen receptor-, progesterone receptor- and human epidermal growth factor receptor-2-negative) cases, and Ki-67 over-expression compared with the group of patients with invasive ductal carcinoma and triple-negative invasive ductal carcinomas. Patients in the metaplastic breast carcinoma group tended to have more local (often chest wall) recurrences (P = 0.038) and distant (often lung) metastases (P = 0.001) than those in the invasive ductal carcinomas group. The prognosis of metaplastic breast carcinoma was poorer than that of invasive ductal carcinoma and triple-negative invasive ductal carcinomas; the 5-year overall survival rate was 54.5% in metaplastic breast carcinoma versus 85.1% in invasive ductal carcinoma, and 73.3% in triple-negative invasive ductal carcinomas (P <0.001). The 5-year disease-free survival rate was 45.5% in metaplastic breast carcinoma versus 71.2% in invasive ductal carcinoma, and 60.3% in triple-negative invasive ductal carcinomas (P <0.001). Multivariate analysis revealed tumor size larger than 5.0 cm, lymph node involvement and Ki-67≥14% were significantly related to 5-year overall survival (P = 0.010; P = 0.010; P = 0.035) and 5-year disease-free survival (P = 0.020; P = 0.018; P = 0.049).ConclusionsMetaplastic breast carcinoma shows a poorer prognosis than both invasive ductal carcinoma and triple-negative invasive ductal carcinomas. Tumor size larger than 5.0 cm, lymph node involvement and Ki-67 ≥14% indicate a poor prognosis in patients with metaplastic breast carcinoma.

Increased expression of fibroblastic growth factor receptor 2 is correlated with poor prognosis in patients with breast cancer.

Although there is growing evidence supporting the hypothesis that fibroblast growth factor receptor 2 (FGFR2) is one of the few candidate genes linked with breast cancer susceptibility, the precise role of FGFR2 protein expression in breast cancer is still unknown. Our study examines FGFR2 protein expression in breast cancer and determines its associations with clinicopathological features and survival.

Promoter Hypermethylation of ARID1A Gene Is Responsible for Its Low mRNA Expression in Many Invasive Breast Cancers

ARID1A (AT-rich interactive domain 1A) has recently been identified as a tumor suppressor gene. Its mRNA expression is significantly low in many breast cancers; this is often associated with more aggressive phenotypes. However, the underlying molecular mechanism for its low expression has not been fully understood. This study was undertaken to evaluate the contribution of gene copy number variation, mutations, promoter methylation and histone modification to ARID1A’s low expression. 38 pairs of breast invasive ductal carcinomas and their normal breast tissue counterparts from the same patients were randomly selected for gene expression and copy number variation detection. Promoter methylation and histone modification levels were evaluated by MeDIP-qPCR and ChIP-qPCR, respectively. PCR product Sanger sequencing was carried out to detect the exon mutation rate. Twenty-two out of 38 invasive ductal carcinomas in the study (57.9%) revealed ARID1A mRNA low expression by realtime RT-PCR. The relative promoter methylation level was, significantly higher in ARID1A mRNA low expression group compared with its high expression group (p<0.001). In the low expression group, nineteen out of 22 invasive ductal carcinomas (86.4%) exhibited ARID1A promoter hypermthylation. In addition, the promoter hypermethylation was accompanied with repressive histone modification (H3K27Me3). Although five out of 38 invasive ductal carcinomas (13.2%) exhibited loss of ARID1A gene copy number by realtime PCR and nine exon novel mutations are seen from eight out of 33 invasive ductal carcinomas (24.2%), there was no statistically significant difference in both ARID1A mRNA low and high expression groups (p = 0.25,and p = 0.68, respectively). We demonstrate that promoter hypermethylation was the main culprit for ARID1A mRNA low expression in invasive ductal carcinomas. The influence of mutation and copy number variation on the expression were statistically insignificant at mRNA level, and were, therefore, not considered the main causes for ARID1A mRNA low expression in invasive breast cancer.

Fangchinoline Induces G1 Arrest in Breast Cancer Cells Through Cell-Cycle Regulation

Fangchinoline, an alkaloid derived from the dry roots of Stephaniae tetrandrine S. Moore (Menispermaceae), has been shown to possess cytotoxic, anti‐inflammatory, and antioxidant properties. In this study, we used Fangchinoline to inhibit breast cancer cell proliferation and to investigate its underlying molecular mechanisms. Human breast cancer cell lines, MCF‐7 and MDA‐MB‐231, were both used in this study. We found that Fangchinoline significantly decreased cell proliferation in a dose‐dependent manner and induced G1‐phase arrest in both cell lines. In addition, upon analysis of expression of cell cycle‐related proteins, we found that Fangchinoline reduced expression of cyclin D1, cyclin D3, and cyclin E, and increased expression of the cyclin‐dependent kinase (CDK) inhibitors, p21/WAF1, and p27/KIP1. Moreover, Fangchinoline also inhibited the kinase activities of CDK2, CDK4, and CDK6. These results suggest that Fangchinoline can inhibit human breast cancer cell proliferation and thus may have potential applications in cancer therapy. Copyright

P16 and P53 Play Distinct Roles in Different Subtypes of Breast Cancer

Breast cancers are heterogeneous and complex diseases, and subtypes of breast cancers may involve unique molecular mechanisms. The p16INK4a and p53 pathways are two of the major pathways involved in control of the cell cycle. They also play key roles in tumorigenesis. However, whether the roles of these pathways differ in the subtypes of breast cancer is unclear. Therefore, p16 and p53 expression were investigated in different breast cancer subtypes to ascertain their contributions to these cancers. A total of 400 cases of non-invasive ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC), including the major molecular subtypes luminal-A, luminal-B, Her-2, and triple-negative subtypes, and 50 cases of normal controls were compared. Luminal-A cancers expressed the lowest level of p16 among the subtypes in DCIS, and the level of p16 expression was up-regulated in the luminal-A of IDC (P<0.008). Triple-negative breast cancers were characterized by a correlation of p53 overexpression with a high level of p16 expression. Luminal lesion types with high p16 expression in DCIS were found to be more likely to develop into aggressive breast cancers, possibly promoted by p53 dysfunction. Taken together, the present study suggest that p16 expression in luminal-A breast cancers is associated with their progression from DCIS to IDC, and both p53 and p16 expressions are important for the development of triple-negative breast cancers in DCIS and IDC.

Methylation profiles of the BRCA1 promoter in hereditary and sporadic breast cancer among Han Chinese

The development of breast cancer is a multistep process associated with complex changes in host gene expression patterns including inactivation of tumor suppressor genes and activation of oncogenes. Critically, hereditary predisposition plays a significant role in cancer susceptibility. However, mutation of the BRCA1 gene is found only in the minority of hereditary breast cancer, which indicates that there might be alternative, novel mechanisms contributing to inactivation of the BRCA1 gene. Studies have shown that aberrant methylation of genomic DNA plays an important role in carcinogenesis. The aim of this study was to investigate whether DNA methylation may be an alternative mechanism for the inactivation of BRCA1 as an epigenetic modification of the genome and whether hereditary breast cancer has a different BRCA1 methylation phenotype pattern than sporadic breast cancer. The pattern of CpG island methylation within the promoter region of BRCA1 was assessed by bisulfite sequencing DNA from peripheral blood cells of 72 patients with hereditary predisposition but without BRCA1 mutations and 30 sporadic breast cancer controls. The overall methylation level in patients with hereditary predisposition was significantly lower than that in the sporadic control group. However, patients with hereditary predisposition showed a significantly higher methylation susceptibility for the sites −518 when compared to controls. These results suggest that there might be different BRCA1 promoter methylation levels and patterns in sporadic and hereditary breast cancer in peripheral blood DNA. These findings may facilitate the early diagnosis of hereditary breast cancer.

Covariation of copy number located at 16q22.1: new evidence in mammary ductal carcinoma.

Copy number variation (CNV) is crucial for gene regulation in humans. A number of studies have revealed that CNV contributes to the initiation and progression of cancer. In this study, we analysed four breast cancer cell lines and six fresh frozen tissues from patients to evaluate the CNV present in the genome using microarray-based comparative genomic hybridization (aCGH). Six genes located at 16q22.1 were analysed by real-time PCR. The real-time PCR analysis revealed that the loss of CDH1/E2F4 may be associated with worse clinical and pathological findings. Interestingly, covariation of CDH1, CDH3, CTCF and E2F4 was found to be associated with triple negative breast cancer and HER-2 receptor status. In conclusion, our study supports the idea that CNV at 16q22.1 in breast cancer is a frequent event; furthermore, it reveals the covariation of CDH1, CDH3, CTCF and E2F4. The role of the covariation is more complex than a simple additive effect of these four separate genes, which may provide a novel target for breast cancer.