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As one of the most widely used anti-diabetic drugs for type II diabetes, metformin has been shown to exhibit anti-cancer activity in recent years. Epidermal growth factor (EGF) and its receptor, EGFR, play important roles in cancer metastasis in various tumors, including breast cancer. Epithelial-mesenchymal transition (EMT) is a critical process for cancer invasion and metastasis. In this study, we use EGF as a metastatic inducer to investigate the effect of metformin on cancer cell migration, invasion and EMT.Human breast cancer MCF-7 cells were exposed to EGF with or without metformin or N-acetyl cysteine (NAC). The effects of metformin on breast cancer cell proliferation were analyzed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The production of reactive oxygen species (ROS) was tested using 2,7-dichlorodihydrofluorecein diacetate (DCFH-DA). The migratory and invasive abilities of tumor cells were analyzed using wound healing assay and transwell invasion assay, respectively. The expressions of E-cadherin, N-cadherin and Snail were tested using real-time quantitative polymerase chain reaction (qRT-PCR) and western blotting at mRNA and protein levels. The activation of protein kinase B (Akt) and nuclear factor kappa B (NF-κB) were measured by western blotting.Our results showed that metformin inhibited breast cancer cell proliferation in a dose-dependent manner with or without EGF. EGF-induced alterations in cell morphology that are characteristic of EMT were reversed by metformin. Metformin also inhibited the EGF-modulated expression of E-cadherin, N-cadherin and Snail and further suppressed cell invasion and migration. In addition, metformin suppressed EGF-induced phosphorylation of Akt and NF-κB. ROS is involved in EGF-induced cancer invasion and activation of phosphatidylinositol 3-kinase (PI3K)/Akt/NF-κB pathway.Taken together, these data indicate that metformin suppresses EGF-induced breast cancer cell migration, invasion and EMT through the inhibition of the PI3K/Akt/NF-κB pathway. These results provide a novel mechanism to explain the role of metformin as a potent anti-metastatic agent in breast cancer cells.

Objective Skill competence is essential for nursing students and experiential teaching method has become increasingly popular in China's nursing education. To systematically evaluate the effects of experiential teaching method on the development of nursing students’ skill competence, and to provide evidence for nursing education. Methods The China National Knowledge Infrastructure, VIP, Wanfang Data, PubMed, and Web of Science databases were searched from their inception until November 28, 2019. We screened the studies according to inclusion and exclusion criteria, extracted the data, and assessed the quality. Then, a meta-analysis was conducted. Results Totally 15 studies were included, and 1,633 nursing students were analyzed by Review Manager5.3 and Stata15.1 software. The results show that the experiential teaching method can significantly improve nursing students’ nursing skills such as training (SMD = 1.05, 95% CI: 0.95–1.16, P = 0.000), learning interest (ES = 0.93, 95% CI: 0.79–1.06), ability to analyze and solve problems (ES = 0.75, 95% CI: 0.55–0.94), ability to judge and innovative thinking (ES = 1.01, 95% CI: 0.77–1.25), abilities of understanding and perception (ES = 0.59, 95% CI: 0.34–0.83), and teaching satisfaction (ES = 1.26, 95% CI: 1.13–1.4). Conclusions The results suggest that the experiential teaching method is more effective for the nursing students’ skill competence than traditional teaching in China. However, due to the heterogeneity and bias risk, a large sample and high-quality studies are needed in future to confirm its effectiveness.

This study examined the association between hector battifora mesothelial antigen-1 (HBME-1) expression and papillary thyroid carcinoma (PTC). A total of 206 patients were enrolled in the current study including 96 PTC patients and 110 patients with benign thyroid nodules (BTN). Immunohistochemistry (Envision) were performed to assess the expression of HBME-1. Receiver operating characteristic curve (ROC) curves were applied to evaluate the diagnostic tumor node metastasis (TNM) value of HBME-1. Specimens from 96 patients with PTC and 110 patients with BTC were reviewed. HBME-1 was positively immunostained in PTC tissue, which was significantly higher than that in BTN tissues (77.1 vs. 5.77 %, P 0.05). Immunohistochemistry also identified that HBME-1 expression did not show any statistically significant differences based on gender, age, tumor size, TNM stage, and lymph node metastasis (P 0.05). Importantly, HBME-1 expression was correlated with infiltration levels and differential levels in PTC (both P 0.05). HBME-1 was found to have high sensitivity (94.5 %) and specificity (77.08 %) for PTC diagnosis. Moreover, HBME-1 had a high specificity (83.33 %) at identifying the differential levels of PTC, but a low sensitivity (22.92 %). The sensitivity and specificity of HBME-1 identifying the infiltration levels of PTC were, respectively, 72.70 and 72.00 %. HBME-1 was highly expressed in PTC tissues, and HBME-1 can serve as a potential biomarker in the diagnosis of PTC.