Background: Cancer stem cells (CSCs) are believed to be ‘seed cell’ in cancer recurrence and metastasis. MicroRNAs (miRNAs) can play an important role in the progression of primary tumor towards metastasis by regulating the epithelial-mesenchymal transition (EMT). The goal of this study was to investigate the effect of miRNA-200c overexpression on the EMT, tumorigenicity and metastasis of epithelial ovarian cancer (EOC) CSCs. Methods: The EOC CD117⁺CD44⁺CSCs were isolated from the human ovarian cancer cell line SKOV3 by using a magnetic-activated cell sorting system, and the lentivirus miR-200c transduced CSCs were then selected for the study. The assays of colony forming, wound healing, cellular migration in vitro and tumor progression in vivo were performed. Results: The miR-200c expression was reduced in the CD117⁺CD44⁺CSCs compared with the non-CD117⁺CD44⁺CSCs. However, the stable overexpression of the miR-200c in the CD117⁺CD44⁺CSCs resulted in a significant down-regulation of ZEB-1 and the Vimentin expression, an upregulation of the E-cadherin expression as well as a decrease of colony forming, migratory and invasion in vitro. Importantly, the miR-200c overexpression significantly inhibited the CD117⁺CD44⁺CSCs xenograft growth and lung metastasis in vivo in nude mice by inhibition of the EMT. In addition, the down-regulation of ZEB-1 showed the same efficacy as the miR-200c overexpression in the CD117⁺CD44⁺CSCs. Conclusion: These findings from this study suggest that the miR-200c overexpression may be considered a critical approach for the EOC CD117⁺CD44⁺CSCs in clinical trials.

Background: Cancer stem cells (CSCs) are thought to be capable of surviving conventional chemotherapeutic treatments because the cells have more resistant to anticancer drugs than common cancer cells. Most in vitro studies in experimental cancer cells have been done in a two-dimensional (2D) monocultures, while accumulating evidence suggests that cancer cells behave differently when they are grown within a three-dimensional (3D) culture system. Results: The CD44⁺CD117⁺cells isolated from human epithelial ovarian cancer SKOV-3 cell line using magnetic-activated cell sorting were found to grow faster than the SKOV-3 cells in the 3D culture and in the nude mice. Anticancer drugs 5FU, docetaxel, cisplatin, and carboplatin were seen to inhibit growth of the CD44⁺CD117⁺ cells by 50% in the 2D culture with IC₅₀ concentration, whereas, in the 3D culture, the four drugs inhibited the cell growth by only 34.4%, 40.8%, 34.8% and 21.9% at 3D one, respectively. Effect of paclitaxel on the CD44⁺CD117⁺cell viability indicated that fewer cells underwent apoptosis in 3D culture than that in 2D one. In addition, anticancer drugs markedly increased the expression of ABCG2 and ABCB1 of CD44⁺CD117⁺cells in 3D culture. Conclusion: Our assay demonstrated that human epithelial ovarian cancer CD44⁺CD117⁺cells possessed the properties of CSCs that exhibited more chemoresistance in the 3D culture than that of in 2D one. The 3D culture provides a realistic model for study of the CSC response to anticancer drugs.

The human umbilical cord mesenchymal stem cells (hUCMSCs) have the ability to migrate into tumors and therefore have been considered as an alternative source of mesenchymal progenitors for the therapy of malignant diseases. The present study was aimed to investigate effect of hUCMSCs as vehicles for a constant source of transgenic interleukin-21 (IL-21) on ovarian cancer in vivo.

Emerging evidence indicates that dysregulated long intervening non-coding RNA (lincRNA) HOTAIR correlates highly with tumor invasion and metastasis but a link between the high expression of HOTAIR and the metastatic cascade of cancer stem cells (CSCs) needs to be further studied. The purpose of this study was to investigate the effect of down-regulated HOTAIR expression on tumorgeniesis and metastasis of epithelial ovarian cancer (EOC) CSCs. CD117+CD44+CSCs were isolated from human EOC SKOV3 cell line by using a magnetic-activated cell sorting system, and were then transfected with the expression vector-based small hairpin RNA targeting HOTAIR; the stably transfected cells were selected for the study. Colony-forming, wound-healing, cellular metastasis and tumorigenicity assays were performed. The results demonstrated that the HOTAIR expression in clinical EOC tissues and SKOV3 CD117+CD44+CSCs was higher than in SKOV3 tumor tissues and non-CD117+CD44+CSCs. The CD117+CD44+-shHOTAIR showed an inhibited HOTAIR expression, reduced cell migration and invasion than CD117+CD44+- scramble, suggesting the inhibition of an epithelial-mesenchymal transition. Moreover, the downregulated HOTAIR expression in CD117+CD44+ CSCs significantly decreased the tumor growth and lung metastasis in xenograft mice. Our findings demonstrated the shHOTAIR-mediated down-regulation of the HOTAIR expression in CD117+CD44+ CSCs can be a promising new opportunity for future clinical trials.

Salmonella typhimurium is a pathogenic gram-negative bacterium, which is found primarily in the intestinal lumen. It often causes diarrhea in infants and young children and leads to food poisoning. Drug resistance of Salmonella typhimurium presented serious complications in clinical patients. In this study, we investigated the antibiotic susceptibility of Salmonella typhimurium standard strain L forms to the third and forth generation cephalosporins, in order to control and eliminate Salmonella typhimurium L forms in infection treatment. Salmonella typhimurium L forms were induced by β-lactam antibiotic cefazolin in the culture medium of bacterial L forms. The antibiotic susceptibility of Salmonella typhimurium L forms was analyzed by K-B drug susceptibility testing. The change trend of drug susceptibility and resistance of Salmonella typhimurium L forms was obtained in accordance with USA clinical and laboratory standards institute (CLSI) evaluation data and statistical analysis. Drug resistance of Salmonella typhimurium L forms showed little increasing trend compared with their parent bacteria. The L form inhibition zone was smaller than in the parent bacteria. However, the drug susceptibility of L forms of Salmonella typhimurium to the third and forth generation cephalosporins remained sensitive.The antibiotic susceptibility of Salmonella typhimurium L forms to the third and forth generation cephalosporins remains sensitive, and the combined use of multi-antibiotics is a convenient and effective method to reduce Salmonella typhimurium L forms occurrence.