3 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:740-750.

Cell-penetrating peptides (CPPs), also known as protein transduction domains, are a class of diverse peptides with 5-30 amino acids. CPPs are divided into cationic, amphipathic and hydrophobic CPPs. They are able to carry small molecules, plasmid DNA, small interfering RNA, proteins, viruses, imaging agents and other various nanoparticles across the cellular membrane, resulting in internalization of the intact cargos. However, the mechanisms of CPP internalization remain to be elucidated. Recently, CPPs have received considerable attention due to their high transduction efficiency and low cytotoxicity. These peptides have a significant potential for diagnostic and therapeutic applications, such as delivery of fluorescent or radioactive compounds for imaging, delivery of peptides and proteins for therapeutic application, and delivery of molecules into induced pluripotent stem cells for directing differentiation. The present study reviews the classifications and transduction mechanisms of CPPs, as well as their potential applications.

B7-H4, another member of costimulatory molecule, has been shown to be overexpressed in multiple types of tumors, including hepatocellular carcinoma (HCC). However, the specific biological role of B7-H4 in HCC still needs to be further explored. In this study, we observed that B7-H4 was highly overexpressed in HCC tissues and cells, and its overexpression strongly correlated with patient's TNM stage, overall survival and early recurrence. Downregulation of B7-H4 significantly suppressed cell growth, invasion, and stemness of HCC by inducing apoptosis in the in vitro experiment. In addition, depletion of B7-H4 could help restore CD8+ T anti-tumor immunity by elevating the expression and secretion levels of CD107a, granzyme A, granzyme B, perforin and IFN-γ. In a xenografted mouse model of HCC, stable depletion of B7-H4 resulted in significantly smaller mean tumor volume and less mean tumor weight after 30 days of growth, compared to the control group. Together, our results provide insights into the diverse functions of B7-H4 involved in the pathogenesis, recurrence and anti-tumor immunity of HCC, indicating B7-H4 as a novel and effective approach for future treatment strategies that benefits anticancer therapy.

The specificities of the methods were similar. The sensitivity of RT-LAMP was ~10-fold higher than that of LAMP for detecting Mtb. Unlike LAMP, RT-LAMP could identify viable bacteria, and was able to detect a single copy of Mtb. Among SCM, LAMP, and RT-LAMP, the latter is the most suitable for wide use in the lower-level hospitals and clinics of China for detecting Mtb in sputum samples.