Cancer metastasis is the main cause of death in breast cancer (BC) patients. Therefore, prediction and treatment of metastasis is critical for enhancing the survival of BC patients. In this study, we aimed to identify biomarkers that can predict metastasis of BC and elucidate the underlying mechanism of the functional involvement of such markers in metastasis. miRNA expression profile was analyzed using a custom microarray system in 422 BC tissues. The relationship between the upregulated miR-665, metastasis and survival of BC was analyzed and verified in another set of 161 BC samples. The biological function of miR-665 in BC carcinogenesis was explored with in vitro and in vivo methods. The target gene of miR-665 and its signaling cascade were also analyzed. There are 399 differentially expressed miRNAs between BC and noncancerous tissues, of which miR-665 is the most upregulated miRNA in the BC tissues compared with non-tumor breast tissues ( P < 0.001). The expression of miR-665 predicts metastasis and poor survival in 422 BC patients, which is verified in another 161 BC patients and 2323 BC cases from online databases. Ectopic miR-665 expression promotes epithelial–mesenchymal transition (EMT), proliferation, migration and invasion of BC cells, and increases tumor growth and metastasis of BC in mice. Bioinformatics, luciferase assay and other methods showed that nuclear receptor subfamily 4 group A member 3 (NR4A3) is a target of miR-665 in BC. Mechanistically, we demonstrated that miR-665 promotes EMT, invasion and metastasis of BC via inhibiting NR4A3 to activate MAPK/ERK kinase (MEK) signaling pathway. Our study demonstrates that miR-665 upregulation is associated with metastasis and poor survival in BC patients, and mechanistically, miR-665 enhances progression of BC via NR4A3/MEK signaling pathway. This study provides a new potential prognostic biomarker and therapeutic target for BC patients.

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Dysregulation of TRIM29 has been reported to be involved in tumorigenesis, but the role of TRIM29 in cervical cancer is unclear. In this study, we first examined TRIM29 expression and found that TRIM29 mRNA and protein expression was upregulated in cervical cancer tissues when compared with the matched adjacent cervical tissues. We further detected TRIM29 protein with immunohistochemistry in 150 paraffin-embedded samples from early-stage cervical cancer patients. The results showed that high expression of TRIM29 was significantly associated with pelvic lymph node metastasis (p=0.002), advanced FIGO stage (p=0.026) and post-operative recurrence (p<0.001). Patients with high expression of TRIM29 had a shorter overall survival (HR 5.042, p<0.001) and disease-free survival (HR 4.260, p<0.001). TRIM29 was proven to be an independent prognostic factor for cervical cancer patients. When endogenous TRIM29 expression was knocked down by siRNAs, cell proliferation, colony formation, migration and invasion in cervical cancer cell lines HeLa and SiHa were obviously inhibited. Meanwhile, TRIM29 knockdown increased E-cadherin expression but decreased the expression of N-cadherin and β-Catenin, which indicated that TRIM29 could promote epithelial-mesenchymal transition (EMT). Mechanically, knockdown of TRIM29 enhanced GSK-3β protein expression and inhibited the expression of β-Catenin and C-myc proteins. GSK-3β is a key upstream suppressor of β-Catenin and c-myc expression is an indicator of Wnt/β-Catenin activity. Therefore, these results demonstrate that TRIM29 promotes tumor progression by activating Wnt/β-Catenin signaling. In conclusion, TRIM29 is overexpressed and associated with survival of early-stage cervical cancer, indicating that TRIM29 may be a potential prognostic biomarker and therapeutic target for cervical cancer.

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Abstract. Lung cancer is the most frequent cause of mortality in cancer patients; non-small-cell lung cancer (NSCLC) accounts for ~80% of lung cancer cases. MicroRNAs (miRNAs) have been revealed to perform an important role in cancer development and progression. Based on a custom miRNA microarray analysis of patients with NSCLC, miRNA-615-3p (miR-615-3p) downregulation was identified in NSCLC tissues compared with normal lung tissues, which suggested that miR-615-3p acted as a tumor suppressor in lung cancer. The overexpression of miR-615-3p was then validated using 40 pairs of NSCLC and adjacent normal tissue samples using a TaqMan reverse transcription-quantitative polymerase chain reaction assay. In order to investigate the tumor suppressor function of miR-615-3p, the ectopic expression of miR-615-3p in the NSCLC A549, H1299 and H1650 cell lines was established. The results revealed that overexpressed miR-615-3p markedly inhibited cell proliferation and colony formation in the 3 NSCLC cell lines compared with the cells overexpressing the negative control sequence (NC). Additional investigation revealed that miR-615-3p overexpression significantly induced apoptosis and cell cycle arrest at the G1 phase in the A549, H1299 and H1650 cell lines compared with the cells overexpressing NC. Finally, ectopic expression of miR-615-3p was found to repress the cell migration and invasion of the 3 lung cancer cell lines. The results of the present study demonstrate, for the first time, that miR-615-3p functions as a tumor suppressor in NSCLC, and may be a novel potential molecular therapeutic target for patients with NSCLC.

Abstract. MicroRNAs are important in cancer development and progression. In the present study, the clinical significance and function of microRNA-711 (miR-711) expression in breast cancer were investigated. The expression level of miR-711 was analyzed in breast cancer tissue samples using reverse transcription-quantitative polymerase chain reaction. Cell proliferation, colony formation, apoptosis and Transwell assays were performed in breast cancer cell lines transfected with miR-711 mimics or inhibitors, or control sequence. miR-711 was found to be upregulated in 30 formalin-fixed paraffin-embedded breast cancer tissue samples compared with paired non-cancerous breast tissues (P<0.05). Furthermore, a higher miR-711 expression was demonstrated to be associated with poor overall and disease-free survival times in 161 breast cancer patients, and miR-711 was identified as an independent prognostic factor using multivariate Cox regression analysis. In vitro, overexpression of miR-711 resulted in a significant increase in proliferation, colony formation, migration and invasion of breast cancer cells. By contrast, downregulating miR-711 inhibited cell proliferation, colony formation, migration and invasion and enhanced the rate of apoptosis of breast cancer cells. To the best of our knowledge, the present study is the first to demonstrate that miR-711 is an independent prognostic factor and serves an important oncogenic function in breast cancer, suggesting that miR-711 is a potential biomarker of prognosis and a molecular therapeutic target in breast cancer. IntroductionBreast cancer is the most common cancer and the leading cause of cancer-associated mortality in women worldwide (1). Breast cancer mortality rates have decreased in North America and several European countries over the past 25 years, principally due to earlier detection and improved treatments (2,3). However, in numerous African and Asian countries, the incidence and mortality rates have increased (4). Therefore, mortality from breast cancer remains a significant health issue globally. In general, the primary risk factors for breast cancer in women are old age (>50 years) and circulating estrogen (5). There are two strategies for enhancing the survival of breast cancer patients: Early detection and appropriate treatment. Primary treatments include surgery, radiotherapy, chemotherapy, endocrine therapy and targeted therapy. Studies have shown that the integrated use of a variety of treatments is advantageous to the prognosis of breast cancer patients (6). At present, formulation of a treatment plan, including surgery and adjuvant therapy, is primarily based on clinical stage and the presence of several limited biomarkers, including estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2 (6). However, the tumor-node-metastasis staging system and these biomarkers do not meet the requirements for personalized therapy and/or precise therapy. Identifying biomarkers for precisely predicting prognosis or for future targeted thera...

MicroRNAs (miRNAs) have been documented as critical regulators in ischemia/reperfusion-induced neuronal death. A better understanding of miRNA-mediated molecular mechanisms in ischemia/reperfusion-induced neuronal death may provide therapeutic targets for cerebral ischemia/reperfusion injury. A growing body of evidence suggests that miR-429 is a apoptosis-related miRNA that is also induced by hypoxia. However, whether miR-429 is involved in regulating neuronal apoptosis during cerebral ischemia/reperfusion injury remains unclear. In this study, the effect of miR-429 on oxygen-glucose deprivation and reoxygenation (OGD/R)-induced neuronal injury was investigated in vitro. The results showed that miR-429 expression levels were upregulated in cultured neurons with OGD/R treatment. The downregulation of miR-429 significantly alleviated OGD/R-induced neuronal injury, whereas upregulation of miR-429 aggravated it. Bioinformatic analysis showed that miR-429 could directly target the 3'-untranslated region of GATA-binding protein 4 (GATA4), which was verified by dual-luciferase reporter assay. Moreover, we found that miR-429 negatively regulated GATA4 expression. Overexpression of GATA4 also significantly alleviated OGD/R-induced neuronal injury. However, knockdown of GATA4 partially reversed the protective effect induced by miR-429 downregulation. Overall, our data showed that downregulation of miR-429 protected neurons against OGD/R-induced injury by promoting GATA4 and suggested a potential therapeutic target for the treatment of cerebral ischemia/reperfusion injury.

Background: Studies have showed that MicroRNA (miRNA) plays an important role in cancer development and progression. We aimed to identify signature for predicting prognosis and response to treatment in breast cancer, which would help in making treatment decisions. Patients and Methods: We retrospectively analyzed miRNA expression profiles by a custom miRNA microarray in 422 archived paraffin-embedded breast cancers and 62 non-cancer breast tissues obtained from the Department of Pathology, Sun Yat-Sen University Cancer Center (Guangzhou, China). The patients with breast cancer were randomly divided into training set (211samples) and test set (211samples). The miRNA signature identified in training set was verified in test set and further confirmed by qRT-PCR method in another independent set including 161 breast cancers acquired from a different medical center. Results: A signature consisting of 36 miRNAs that were differently expressed between breast cancer and breast tissue was established in training set with an accuracy of 99.5% for distinguishing breast cancer from non-cancer breast tissues. The 36-miRNA signature was corroborated in test set with the same accuracy (99.5%). Then 5 miRNAs, which were significantly associated with patient survival, were constructed a signature and used to compute risk score in training set. Patients were divided into high- or low-risk group using the median risk score as a cutoff. Survival analysis showed that patients with high risk scores had poor prognosis in the training set, which was confirmed in the test set and independent set. This 5-miRNA signature was proven to be an independent prognostic predictor and could significantly improve the prognostic accuracy of TNM staging system. More important, the 5-miRNA signature could predict response to chemotherapy/radiotherapy in breast cancer patients after radical mastectomy. Conclusion: We identified a 36-miRNA signature that could distinguish breast cancer from non-tumor breast tissue, and a 5-miRNA signature that could predict survival and response to treatment, which could guide neoadjuvant therapy in breast cancer patients. The results in this study suggest that 5-miRNA signature will have a huge potential clinical implication in management of patients with breast cancer. Funding: National Natural Science Foundation of China/Joint Research Fund for Oversea Scholar (Grant No: 81228104 to Yibing Kang and Hui-Yun Wang). Citation Format: Jing-Ye Hu, Jun Tang, Wei Yi, Rong Deng, Mei-Yin Zhang, Guo-Liang Huang, Hui-Zhong Zhang, Jie-Hua He, X.F. Steven Zheng, Yibing Kang, Hui-Yun Wang. A 5-microRNA signature for prediction of prognosis and response to treatment in breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4013. doi:10.1158/1538-7445.AM2015-4013