Ling Yao

Cytidine Deaminase Axis Modulated by miR-484 Differentially Regulates Cell Proliferation and Chemoresistance in Breast Cancer

There has been little study of how the evolution of chemoresistance in cancer affects other aspects of disease pathogenesis. Here, we show that an important chemoresistance axis driven by cytidine deaminase (CDA) also acts to suppress cell-cycle progression by regulating cyclin E-CDK2 signaling. We found that CDA was regulated by miR-484 in a gemcitabine-resistant model of breast cancer. Elevating miR-484 expression reversed the CDA effects, thereby enhancing gemcitabine sensitivity, accelerating cell proliferation, and redistributing cell-cycle progression. Conversely, elevating CDA to restore its expression counteracted the chemosensitization and cell proliferative effects of miR-484. In clinical specimens of breast cancer, CDA expression was frequently downregulated and inversely correlated with miR-484 expression. Moreover, high expression of CDA was associated with prolonged disease-free survival in studied cohorts. Collectively, our findings established that miR-484-modulated CDA has a dual impact in promoting chemoresistance and suppressing cell proliferation in breast cancer, illustrating the pathogenic tradeoffs associated with the evolution of chemoresistance in this malignant disease.

Expression of autophagy-related proteins ATG5 and FIP200 predicts favorable disease-free survival in patients with breast cancer

Autophagy is a self-digesting process that is primarily responsible for the removal and recycling of long-lived proteins and damaged organelles to maintain the homeostasis of the cell. Recent studies have indicated dual roles for autophagy in cancer: suppression of tumor progression and promotion of survival. In this study, we sought to investigate the prognostic value of two autophagy-related proteins, autophagy-related gene 5 (ATG5) and FAK family kinase-interacting protein of 200 kDa (FIP200), in patients with operable breast cancer. More specifically, the expression of ATG5 and FIP200 was evaluated by immunohistochemistry (IHC) in surgical specimens collected from 200 patients who were diagnosed with histologically proven invasive ductal breast cancer. A stepwise Cox multivariate analysis was then performed to construct a risk prediction model. In this retrospective cohort study, both ATG5 (HR = 0.465, 95% CI 0.247-0.872, P = 0.017) and FIP200 (HR = 0.521, 95% CI 0.278-0.979, P = 0.043) correlated with prolonged disease-free survival (DFS). In a receiver operating characteristic (ROC) analysis, the addition of ATG5 and FIP200 expression led to a significantly improved area under the time-dependent ROC curve (AUC) at 3 years (0.748 versus 0.680, P < 0.001) and 5 years (0.756 versus 0.699, P < 0.001). Collectively, our findings established the prognostic significance of ATG5 and FIP200 in patients with breast cancer.

Positive expression of miR-361-5p indicates better prognosis for breast cancer patients

BACKGROUND MicroRNA-361-5p (miR-361-5p) has been reported to be tumor suppressor in colorectal, gastric and prostate cancer, but as an oncogene in cervical cancer. No previous research has focused on the expression of miR-361-5p and its exact prognostic role in breast cancer (BC). METHODS In this study, a tissue microarray (TMA)-based miRNA detection in situ hybridization (ISH) with LNA probe was used to detect miR-361-5p expression in 375 BC tissue. The expression level of miR-361-5p in BC and its potential prognostic value was investigated. RESULTS Positive miR-361-5p staining was observed in 78.7% (N=295; 78.7% positive, 21.3% negative) in the 375 cases. The clinical outcome of patients with positive miR-361-5p expression [median disease-free survival (DFS) time 95.52 months] was significantly better than that of patients (median DFS time 82.33 months) with negative miR-361-5p expression (P=0.002). Moreover, the prognostic value of miR-361-5p was most significant among patients with triple-negative breast cancer (TNBC) for DFS (P=0.004). CONCLUSIONS These results indicated that miR-361-5p expression is an independent predictive factor for better prognosis in BC.

High expression of microRNA-454 is associated with poor prognosis in triple-negative breast cancer

MicroRNA-454 (miR-454) has been reported to play an oncogenic or tumor suppressor role in most cancers. However, the clinical relevance of miR-454 in breast cancer remains unclear. We examined the expression of miR-454 in a tissue microarray containing 534 breast cancer specimens from female patients at Fudan University Shanghai Cancer Center using in situ hybridization (ISH). Of these, 250 patients formed the training set and the other 284 were the validation set. The relationship between miR-454 and clinical outcome was analyzed by the Kaplan-Meier method. High expression of miR-454 indicated worse disease-free survival (DFS) in both cohorts (P = 0.006 for training set; P = 0.010 for validation set). Furthermore, in the triple-negative breast cancer (TNBC) subtype, miR-454 was positively correlated with worse clinical outcome (P = 0.013 for training set, P = 0.014 for validation set). In addition, patients in the low miR-454 expression cohort had better response to anthracycline compared to non-anthracycline chemotherapy (P = 0.056), but this difference was not observed in the high miR-454 expression cohort. Our findings indicated that miR-454 is a potential predictor of prognosis and chemotherapy response in TNBC.

High levels of nucleolar spindle-associated protein and reduced levels of BRCA1 expression predict poor prognosis in triple-negative breast cancer

Purpose Nucleolar spindle-associated protein (NuSAP1) is an important mitosis-related protein, and aberrant NuSAP1 expression is associated with abnormal spindles and mitosis. This study investigated the prognostic value of NuSAP1 in breast cancer. Methods Two sets of tissue microarrays (TMAs) that included samples from 450 breast cancer patients were constructed, of which 250 patients were training set and the other 200 patients were validation set. Immunohistochemical staining was performed to determine the NuSAP1 levels. A Kaplan-Meier analysis was used to estimate the prognostic value of NuSAP1 in breast cancer. A stepwise Cox analysis was performed to construct a risk-prediction model for triple-negative breast cancer (TNBC). All statistical analysis was performed with SPSS software. Results There were 108 (43.5%) and 88 (44.0%) patients expressed NuSAP1 in the training set and validation set respectively. High levels of NuSAP1 expression were related to poor disease-free survival (DFS) in both training (P = 0.028) and validation (P = 0.006) cohorts, particularly in TNBC. With combination of two cohorts, both NuSAP1 (HR = 4.136, 95% CI: 1.956–8.747, P < 0.001) and BRCA1 (HR = 0.383, 95% CI: 0.160–0.915, P = 0.031) were independent prognostic indicators of DFS in TNBC. A receiver operating characteristic (ROC) analysis revealed that the combination of NuSAP1 and BRCA1 significantly improved the prognostic power compared with the traditional model (0.778 versus 0.612, P < 0.001). Conclusions Our study confirms the prognostic value of NuSAP1 in breast cancer. The combination of NuSAP1 and BRCA1 could improve the DFS prediction accuracy in TNBC.

The BMP inhibitor DAND5 in serum predicts poor survival in breast cancer

Background & Aims Breast cancer (BC) is prevalent worldwide malignant cancer. Improvements in timely and effective diagnosis and prediction are needed. As reported, secreted DAND5 is contributed to BC metastasis. We aim to assess whether DAND5 in peripheral blood serum could determine BC-specific mortality. Methods We used immunohistochemistry staining to detect DAND5 expression in our BC tissue array including 250 samples. Angiogenesis assay and xenograft mice model were used to examine the secreted DAND5 function in BC progression. Serum concentration of DAND5 was examined by ELISA in 1730 BC patients. Kaplan-Meier and adjusted Cox proportional hazards models were utilized to analyze the prognosis and survival of BC patients. Results Tissue array results showed that positive DAND5 staining cases displayed a higher likelihood of occurrence of disease events (HR=5.494; 95% CI: 1.008-2.353; P=0.048) in univariate analysis and remained the same trend in multivariate analysis (HR=2.537; 95% CI: 1.056-6.096; P=0.037). DAND5 positive patients exerted generally poor DFS (P=0.041) in the Kaplan-Meier survival analysis. Furthermore, secreted DAND5 promoted tumor growth and angiogenesis in vitro and in vivo. In addition, positive DAND5 in BC patients serum was associated with increased risk of disease events occurrence (univariate: HR=1.58; 95% CI: 1.206-2.070; P=0.001; multivariate: HR=1.4; 95% CI: 1.003-1.954; P=0.048) in univariate and multivariate survival analysis. In the Kaplan-Meier analysis, serum DAND5 positively correlated with poor DFS (P=0.001) and DDFS (P=0.002). Conclusions DAND5 was correlated with poor survival and could serve as an easily detectable serum biomarker to predict the survival of breast cancer.

An aberrant spliced transcript of focal adhesion kinase is exclusively expressed in human breast cancer.

PurposeTo clarify the roles of a new aberrantly spliced transcript of FAK that lacks exon 26 (denoted -26-exon FAK) in human breast cancers.MethodsTranscripts of FAK expressed in 102 human breast tumor tissues and 52 corresponding normal tissues were analyzed by RT-PCR and DNA sequencing, as well as agarose gel electrophoresis. The cDNA of -26-exon FAK was cloned and expressed in MCF-10A cells, and then the kinase activity, cellular localization and migration capability of FAK were examined by western blotting, immunofluorescent staining and migration assays, respectively. The expression levels of FAK were analyzed by western blotting in MCF-7 cells treated with TNF-α or in MCF-10A cells upon serum deprivation. The MCF-10A cells transfected with a plasmid expressing -26-exon FAK were cultured in serum-free medium and cell apoptosis was analyzed by flow cytometry.ResultsThe -26-exon FAK transcript was exclusively present in human breast tumor tissues and the encoded protein possessed the same kinase activity, cellular localization and cell migration-promoting ability as wild-type FAK. In MCF-7 cells treated with TNF-α, and in MCF-10A cells upon serum deprivation, the -26-exon FAK was resistant to proteolysis while wild-type FAK was largely cleaved. In addition, the -26-exon FAK, but not wild-type FAK, inhibited cell apoptosis.ConclusionsThe -26-exon FAK transcript, which is exclusively expressed in human breast tumor tissues, encodes a protein that possesses the same kinase activity and biological function as the wild-type FAK, but because it is resistant to the caspase-mediated cleavage that induces the proteolysis of the wild-type form, it ultimately prevents apoptosis.

ID2 predicts poor prognosis in breast cancer, especially in triple-negative breast cancer, and inhibits E-cadherin expression

Background Inhibitors of DNA-binding (ID) proteins are known as important modulators in the regulation of cell proliferation and differentiation. This study sought to investigate the prognostic value of ID proteins in breast cancer. Methods The prognostic role of ID proteins in human breast cancer was investigated in 250 breast cancers, via tissue microarrays. The messenger (m)RNA and protein levels of E-cadherin were examined by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and Western blotting, in cells overexpressing IDs. Dual-luciferase report assay was used to investigate the potential mechanism, and a migration assay was performed to investigate the influence of IDs on cell migratory activity. Results The survival analysis with Kaplan–Meier and Cox regression showed that ID2 expression level, which correlated with estrogen receptor status and E-cadherin abundance, served as an independent prognostic factor for disease-free survival (DFS) (P=0.013). The prognostic value of ID2 for DFS was most significant in triple-negative breast cancer patients (P=0.009). We also found that ID2 was negatively correlated with E-cadherin expression by correlation analysis (P=0.020, Pearson’s R=−0.155). Subsequently, we explored the biological rationale and uncovered that the enforced expression of ID proteins could suppress E-cadherin expression significantly, thus increasing the migration ability of mammary epithelial cells. Then using a combination of ID2 and E-cadherin expression, the patients were classified into four subgroups with different DFS (P=0.023). Conclusion The overexpression of ID2 can be used as a prognostic marker in breast cancer patients, especially in triple-negative breast cancer patients. ID proteins were still, unexpectedly, revealed to inhibit E-cadherin abundance.

Elevated miR-301a expression indicates a poor prognosis for breast cancer patients

Although microRNA-301a (miR-301a) has been reported to function as an oncogene in many human cancers, there are limited data regarding miR-301a and breast tumours. In this study, we first detected the expression of miR-301a using an in situ hybridization (ISH) -based classification system in 380 samples of BC tissue, including both non-TNBC (triple-negative breast cancer) and TNBC specimens. Our results suggest that analysing miR-301a expression in breast tissue biopsy specimens at the time of diagnosis could have the potential to identify patients who might be candidates for active surveillance. We validated our results that higher expression of miR-301a is associated with a decreased OS in independent public breast cancer databases, such as TCGA and METABRIC, using the online webtool Kaplan-Meier Plotter, which provided additional powerful evidence to confirm the prognostic value of miR-301a. MiR-301a may serve as a potential therapeutic target for patients with breast cancer. According to our results, miR-301a should be considered, and novel therapeutic options are needed to target this aggressive miR-301a-positive type of breast cancer to reduce recurrence and the mortality rate.

MicroRNA-493 is a prognostic factor in triple-negative breast cancer

Breast cancer is one of the most common malignant diseases in women. Triple‐negative breast cancer (TNBC) shows higher aggressiveness and recurrence rates than other subtypes, and there are no effective targets or tailored treatments for TNBC patients. Thus, finding effective prognostic markers for TNBC could help clinicians in their ability to care for their patients. We used tissue microarrays (TMAs) to detect microRNA‐493 (miR‐493) expression in breast cancer samples. A miRCURY LNA detection probe specific for miR‐493 was used in in situ hybridization assays. Staining results were reviewed by two independent pathologists and classified as high or low expression of miR‐493. Kaplan–Meier survival plots and multivariate Cox analysis were carried out to clarify the relationship between miR‐493 and survival. In the Kaplan–Meier analysis, patients with high miR‐493 expression had better disease‐free survival than patients with low miR‐493 expression. After adjusting for common clinicopathological factors in breast cancer, the expression level of miR‐493 was still a significant prognostic factor in breast cancer. Further subtype analysis revealed that miR‐493 expression levels were only significantly prognostic in TNBC patients. These results were validated in the Molecular Taxonomy of Breast Cancer International Consortium database for overall survival. We proved the prognostic role of miR‐493 in TNBC by using one of the largest breast cancer TMAs available and validated it in a large public RNA sequencing database.