[Advances in the biological characteristics and stem maintenance mechanisms of tumor stem cells].

Tumor is one of the most serious diseases that threaten human health and social development, and it is the second most common cause of death worldwide. The latest statistics show that malignant tumors have surpassed cardiovascular disease as the leading cause of death in developed countries. Drug resistance, metastasis, and recurrence of tumors continue to present urgent challenges in clinical treatment. Tumor stem cells (TSCs) are a specific subset of cells that possess high capabilities of self-renewal, differentiation potential, tumorigenicity and drug resistance. They are resistant to non-specific treatment methods such as chemotherapy and radiotherapy, and play a crucial role in tumor initiation, metastasis, drug resistance, and recurrence. The surface markers, stemness maintenance mechanisms, microenvironment, and metabolic reprogramming of TSCs have become areas of intense research focus. The latest research results provide novel targets and strategies for the identification of TSCs and targeted therapy. This paper reviews the surface markers (CD133, CD44, etc.), self-renewal and epithelial mesenchymal transition (EMT) signaling pathways (Wnt/ß-catenin, Hedgehog, etc.), microenvironment characteristics, metabolic reprogramming (glycolysis, oxidative phosphorylation, etc.) and their roles in the initiation, development, metastasis and drug resistance of TSCs.

Duplex Identification of Staphylococcus aureus by Aptamer and Gold Nanoparticles.

Staphylococcus aureus is the top common pathogen causing infections and food poisoning. Identification of S. aureus is crucial for the disease diagnosis and regulation of food hygiene. Herein, we report an aptamer-AuNPs based method for duplex identification of S. aureus. Using AuNPs as an indicator, SA23, an aptamer against S. aureus, can well identify its target from Escherichia coli, Listeria monocytogenes and Pseudomonas aeruginosa. Furthermore, we find citrate-coated AuNPs can strongly bind to S. aureus, but not bind to Salmonella enterica and Proteus mirabilis, which leads to different color changes in salt solution. This colorimetric response is capable of distinguishing S. aureus from S. enteritidis and P. mirabilis. Thus, using the aptasensor and AuNPs together, S. aureus can be accurately identified from the common pathogens. This duplex identification system is a promising platform for simple visual identification of S. aureus. Additionally, in the aptasensing process, bacteria are incubated with aptamers and then be removed before the aptamers adding to AuNPs, which may avoid the interactions between bacteria and AuNPs. This strategy can be potentially applied in principle to detect other cells by AuNPs-based aptasensors.