No abstract

High-risk human papillomaviruses (HR-HPVs) are consistently associated with human cervical cancer Additionally, the early oncoproteins of HPVs E5, E6 and E7 are known to contribute to tumor progression. The role of E5 is still nebulous. In this study, we aimed to explore the mechanism of E5 action during the human cervical carcinogenesis process. We created four cell models overexpressing HPV16 or HPV18 E5 (HPV16/18 E5) and investigated their ability to proliferate, along with their metastatic characteristics such as migration and invasion. The expression of HPV16/18 E5 protein in various cell lines was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR). In addition, we compared the levels of phosphorylated paxillin as well as E-cadherin in cell models and controls by western blot analysis. Finally, we assessed the tumor growth rate of human cervical cancer cells overexpressing HPV16/18 E5 in vivo. We discovered that the expression of HPV16/18 E5 consistently increased the malignant potential of various human cervical cancer cells compared with the primary counterparts. We demonstrated the involvement of HPV16/18 E5 in proliferation, migration, invasion and regulation of the actin cytoskeleton in human cervical cancer cells. In particular we discovered that HPV16/18 E5 overexpression in human cervical cancer cells correlated with higher levels of paxillin proteins phosphorylated on tyrosine residues and with the downregulation of E-cadherin. Importantly, injection of HPV16/18 E5-overexpressing human cervical cancer cells into mice increased both HPV-and non-HPV-derived tumor growth. Collectively, our data indicate that HPV16/18 E5 influences progression of the human cervical cancer malignant phenotype. This study provides new insights into HPV16/18 E5 as a possible agent that may have an impact on the therapeutic strategies targeting human cervical cancer.

Aims: The embryonic stem cell-derived cardiomyocytes (ES-CM) is one of the promising cell sources for repopulation of damaged myocardium. However, ES-CMs present immature structure, which impairs their integration with host tissue and functional regeneration. This study used murine ES-CMs as an in vitro model of cardiomyogenesis to elucidate the effect of puerarin, the main compound found in the traditional Chinese medicine the herb Radix puerariae, on t-tubule development of murine ES-CMs. Methods: Electron microscope was employed to examine the ultrastructure. The investigation of transverse-tubules (t-tubules) was performed by Di-8-ANEPPS staining. Quantitative real-time PCR was utilized to study the transcript level of genes related to t-tubule development. Results: We found that long-term application of puerarin throughout cardiac differentiation improved myofibril array and sarcomeres formation, and significantly facilitated t-tubules development of ES-CMs. The transcript levels of caveolin-3, amphiphysin-2 and junctophinlin-2, which are crucial for the formation and development of t-tubules, were significantly upregulated by puerarin treatment. Furthermore, puerarin repressed the expression of miR-22, which targets to caveolin-3. Conclusion: Our data showed that puerarin facilitates t-tubule development of murine ES-CMs. This might be related to the repression of miR-22 by puerarin and upregulation of Cav3, Bin1 and JP2 transcripts.

Aims: Previous studies have shown the dramatic changes in electrical properties of murine fetal cardiomyocytes, while details on inward rectifier potassium current (IK1) are still seldom discussed. Thus we aimed to characterize the functional expression and functional role of IK1 in murine fetal ventricular cardiomyocytes. Methods: Whole cell patch clamp was applied to investigate the electrophysiological properties of IK1. Quantitative real-time PCR, western blotting and double-label immunofluorescence were further utilized to find out the molecular basis of IK1. Results: Compared to early developmental stage (EDS), IK1 at late developmental stage (LDS) displayed higher current density, stronger rectifier property and faster activation kinetics. It was paralleled with the downregulation of Kir2.3 and the upregulation of Kir2.1/Kir2.2. IK1 contributed to maintain the maximum diastolic potential (MDP), late repolarization phase (LRP) as well as the action potential duration (APD). However, the contribution to MDP and velocity of LRP did not change significantly with maturation. Conclusions: During fetal development, the switch of IK1 subtypes from Kir2.1/Kir2.3 to Kir2.1 resulted in the dramatic changes in IK1 electrophysiological properties.