Of miR-27a was associated with shorter disease-free survival and overall survival of breast cancer patients. Both of the univariate analyses and multivariate analyses indicated that miR-27a expression was an Pluripotin site independent prognostic factor for breast cancer progression. Several recent studies have demonstrated that the expression of miR-27a is up-regulated in several types of solid tumors, including colon, gastric, cervical and breast cancers [10,12,24,26]. The widespread overexpression of miR-27a in cancer has led to the belief that miR-27a is an oncogenic microRNA. Cell culture and animal experiments support this speculation, showing that the down-regulation of 
miR-27a expression can suppress cell proliferation and slow tumor growth. In gastric cancer cells, the reduction of miR-27a inhibited cell growth in both in vitro and nude mice assays [27]. MiR-27a might mediate cell proliferation by the regulation of cyclin D1 and p21. In addition, it could promote the migration of pancreatic cancer cells by targetingTable 2. Univariate and Multivariate Analyses of Different Prognostic Parameters on Breast Cancer Disease-free Survival Rates.Univariate analyses P Age Menopause Histological grade T-stage N-stage ER status PR status Her-2 status miR-27a ZBTB10 0.893 0.915 0.745 0.000 0.016 0.935 0.333 0.055 0.001 0.000 Regression coefficient (SE) 20.05 (0.371) 0.048(0.449) 0.095 (0.291) 1.151(0.292) 0.497(0.207) 20.038(0.463) 0.72(0.744) 0.84(0.437) 1.728(0.513) 21.846(0.485)Multivariate analyses P Relative risk 95 Confidence interval0.3.1.653?.0.054 0.012 0.025 0.4.778 3.373 3.573 0.0.973?3.478 1.300?.750 1.176?0.860 0.089?.(SE) standard error; multivariate analysis; Cox proportional hazard regression model, stepwise forward LR. doi:10.1371/journal.pone.0051702.tMiR-27a as a Predictor of Invasive Breast CancerTable 3. Univariate and Multivariate Analyses of Overall Survival Rates in Patients with Breast Cancers by Cox-Regression Analysis.Univariate analyses P Age Menopause Histological grade T-stage N-stage ER status PR status Her-2 status miR-27a ZBTB10 0.851 0.872 0.721 0.000 0.016 0.958 0.358 0.028 0.001 0.000 Regression coefficient (SE) 20.068 (0.361) 0.072(0.45) 0.104(0.292) 1.2(0.293) 0.494(0.204) 20.024(0.463) 0.684(0.744) 0.977(0.443) 1.739(0.513) 21.774(0.484)Multivariate analyses P Relative risk 95 23727046 Confidence interval0.3.1.645?.0.4.1.665?2.(SE) standard error; multivariate analysis; Cox proportional hazard regression model, stepwise forward LR. doi:10.1371/journal.pone.0051702.tSprouty2 [28] and increase 24786787 endothelial cell sprouting by regulating the expression of the angiogenesis inhibitor semaphorin 6A (SEMA6A) [29]. In addition, miR-27a plays an important role in mediating drug resistance by targeting multiple drug-resistance related genes. MiR-27a modulated MDR1/P-glycoprotein expression in human ovarian cancer cells by targeting HIPK2 [15] and could reverse the multidrug resistance of esophageal squamous cell carcinoma through regulation of MDR1 and apoptosis [14]. This study focused on the potential relationship between the expression level of miR-27a and various clinicopathological characteristics of breast cancer patients, as well as disease-free survival and overall survival. It is worth noting that high levels of miR-27a appear to be significantly correlated with tumor size, lymph node metastases, distant metastasis and poor PS 1145 web prognosis in patients with breast cancer. MiR-27a was up-regulated in patients presenting with metastase.Of miR-27a was associated with shorter disease-free survival and overall survival of breast cancer patients. Both of the univariate analyses and multivariate analyses indicated that miR-27a expression was an independent prognostic factor for breast cancer progression. Several recent studies have demonstrated that the expression of miR-27a is up-regulated in several types of solid tumors, including colon, gastric, cervical and breast cancers [10,12,24,26]. The widespread overexpression of miR-27a in cancer has led to the belief that miR-27a is an oncogenic microRNA. Cell culture and animal experiments support this speculation, showing that the down-regulation of miR-27a expression can suppress cell proliferation and slow tumor growth. In gastric cancer cells, the reduction of miR-27a inhibited cell growth in both in vitro and nude mice assays [27]. MiR-27a might mediate cell proliferation by the regulation of cyclin D1 and p21. In addition, it could promote the migration of pancreatic cancer cells by targetingTable 2. Univariate and Multivariate Analyses of Different Prognostic Parameters on Breast Cancer Disease-free Survival Rates.Univariate analyses P Age Menopause Histological grade T-stage N-stage ER status PR status Her-2 status miR-27a ZBTB10 0.893 0.915 0.745 0.000 0.016 0.935 0.333 0.055 0.001 0.000 Regression coefficient (SE) 20.05 (0.371) 0.048(0.449) 0.095 (0.291) 1.151(0.292) 0.497(0.207) 20.038(0.463) 0.72(0.744) 0.84(0.437) 1.728(0.513) 21.846(0.485)Multivariate analyses P Relative risk 95 Confidence interval0.3.1.653?.0.054 0.012 0.025 0.4.778 3.373 3.573 0.0.973?3.478 1.300?.750 1.176?0.860 0.089?.(SE) standard error; multivariate analysis; Cox proportional hazard regression model, stepwise forward LR. doi:10.1371/journal.pone.0051702.tMiR-27a as a Predictor of Invasive Breast CancerTable 3. Univariate and Multivariate Analyses of Overall Survival Rates in Patients with Breast Cancers by Cox-Regression Analysis.Univariate analyses P Age Menopause Histological grade T-stage N-stage ER status PR status Her-2 status miR-27a ZBTB10 0.851 0.872 0.721 0.000 0.016 0.958 0.358 0.028 0.001 0.000 Regression coefficient (SE) 20.068 (0.361) 0.072(0.45) 0.104(0.292) 1.2(0.293) 0.494(0.204) 20.024(0.463) 0.684(0.744) 0.977(0.443) 1.739(0.513) 21.774(0.484)Multivariate analyses P Relative risk 95 23727046 Confidence interval0.3.1.645?.0.4.1.665?2.(SE) standard error; multivariate analysis; Cox proportional hazard regression model, stepwise forward LR. doi:10.1371/journal.pone.0051702.tSprouty2 [28] and increase 24786787 endothelial cell sprouting by regulating the expression of the angiogenesis inhibitor semaphorin 6A (SEMA6A) [29]. In addition, miR-27a plays an important role in mediating drug resistance by targeting multiple drug-resistance related genes. MiR-27a modulated MDR1/P-glycoprotein expression in 
human ovarian cancer cells by targeting HIPK2 [15] and could reverse the multidrug resistance of esophageal squamous cell carcinoma through regulation of MDR1 and apoptosis [14]. This study focused on the potential relationship between the expression level of miR-27a and various clinicopathological characteristics of breast cancer patients, as well as disease-free survival and overall survival. It is worth noting that high levels of miR-27a appear to be significantly correlated with tumor size, lymph node metastases, distant metastasis and poor prognosis in patients with breast cancer. MiR-27a was up-regulated in patients presenting with metastase.
