LincRNA-p21 alleviates atherosclerosis progression through regulating the miR-221/SIRT1/Pcsk9 axis

Atherosclerosis (AS) is the main aetiology of coronary heart disease, cerebral infarction and peripheral vascular disease in humans. Long-noncoding RNA (LincRNA)-p21 has been reported to participate in the development of AS. Therefore, this study was designed to investigate the mechanism of LincRNA-p21 on suppressing the development of AS. We fed ApoE^−/− mice with a high-fat diet to induce an AS mouse model where the lesion area of AS and the extent of lipid deposition were measured. The binding of LincRNA-p21 and miR-221 or miR-221 and SIRT1 was measured using a dual luciferase reporter gene assay and RIP. Following loss- and gain- function assays, CCK8, EdU, Transwell assay and scratch test were performed to determine the biological processes of human aortic endothelial cells (HAECs). miR-221 was highly expressed while SIRT1 was poorly expressed in AS. LincRNA-p21 acted as a sponge for miR-221. miR-221 targeted and negatively regulated the expression of SIRT1. LincRNA-p21 promoted the deacetylation of Pcsk9 by SIRT1 by competitively binding to miR-221, whereby promoting HAEC proliferation, migration and tube formation. In conclusion, LincRNA-p21 acted as a molecular sponge for miR-221 to promote deacetylation of the promoter region of Pcsk9 by SIRT1, therefore preventing the development of AS.     

MET inhibition enhances PARP inhibitor efficacy in castration-resistant prostate cancer by suppressing the ATM/ATR and PI3K/AKT pathways

Up to 30% of patients with metastatic castration-resistant prostate cancer (CRPC) patients carry altered DNA damage response genes, enabling the use of poly adenosine diphosphate–ribose polymerase (PARP) inhibitors in advanced CRPC. The proto-oncogene mesenchymal–epithelial transition (MET) is crucial in the migration, proliferation, and invasion of tumour cells. Aberrant expression of MET and its ligand hepatocyte growth factor is associated with drug resistance in cancer therapy. Here, we found that MET was highly expressed in human CRPC tissues and overexpressed in DU145 and PC3 cells in a drug concentration-dependent manner and is closely related to sensitivity to PARP inhibitors. Combining the PARP inhibitor olaparib with the MET inhibitor crizotinib synergistically inhibited CRPC cell growth both in vivo and in vitro. Further analysis of the underlying molecular mechanism underlying the MET suppression-induced drug sensitivity revealed that olaparib and crizotinib could together downregulate the ATM/ATR signaling pathway, inducing apoptosis by inhibiting the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway, enhancing the olaparib-induced antitumour effect in DU145 and PC3 cells. In conclusion, we demonstrated that MET inhibition enhances sensitivity of CRPC to PARP inhibitors by suppressing the ATM/ATR and PI3K/AKT pathways and provides a novel, targeted therapy regimen for CRPC.     

The FYVE Domain of Smad Anchor for Receptor Activation (SARA) Is Required to Prevent Skin Carcinogenesis,but Not in Mouse Development

Smad Anchor for Receptor Activation (SARA) has been reported as a critical role in TGF-β signal transduction by recruiting non-activated Smad2/3 to the TGF-β receptor and ensuring appropriate subcellular localization of the activated receptor-bound complex. However, controversies still exist in previous reports. In this study, we describe the expression of two SARA isoforms, SARA₁ and SARA₂, in mice and report the generation and characterization of SARA mutant mice with FYVE domain deletion. SARA mutant mice developed normally and showed no gross abnormalities. Further examination showed that the TGF-β signaling pathway was indeed altered in SARA mutant mice, with the downregulation of Smad2 protein expression. The decreasing expression of Smad2 was caused by enhancing Smurf2-mediated proteasome degradation pathway. However, the internalization of TGF-β receptors into the early endosome was not affected in SARA mutant mouse embryonic fibroblasts (MEFs). Moreover, the downregulation of Smad2 in SARA mutant MEFs was not sufficient to disrupt the diverse cellular biological functions of TGF-β signaling, including growth inhibition, apoptosis, senescence, and the epithelial-to-mesenchymal transition. Our results indicate that SARA is not involved in the activation process of TGF-β signal transduction. Using a two-stage skin chemical carcinogenesis assay, we found that the loss of SARA promoted skin tumor formation and malignant progression. Our data suggest a protective role of SARA in skin carcinogenesis.     

Self-Rotation of Cells in an Irrotational AC E-Field in an Opto-Electrokinetics Chip

The use of optical dielectrophoresis (ODEP) to manipulate microparticles and biological cells has become increasingly popular due to its tremendous flexibility in providing reconfigurable electrode patterns and flow channels. ODEP enables the parallel and free manipulation of small particles on a photoconductive surface on which light is projected, thus eliminating the need for complex electrode design and fabrication processes. In this paper, we demonstrate that mouse cells comprising melan-a cells, RAW 267.4 macrophage cells, peripheral white blood cells and lymphocytes, can be manipulated in an opto-electrokinetics (OEK) device with appropriate DEP parameters. Our OEK device generates a non-rotating electric field and exerts a localized DEP force on optical electrodes. Hitherto, we are the first group to report that among all the cells investigated, melan-a cells, lymphocytes and white blood cells were found to undergo self-rotation in the device in the presence of a DEP force. The rotational speed of the cells depended on the voltage and frequency applied and the cells'' distance from the optical center. We discuss a possible mechanism for explaining this new observation of induced self-rotation based on the physical properties of cells. We believe that this rotation phenomenon can be used to identify cell type and to elucidate the dielectric and physical properties of cells.     

Priming Effects in Boreal Black Spruce Forest Soils: Quantitative Evaluation and Sensitivity Analysis

Laboratory studies show that introduction of fresh and easily decomposable organic carbon (OC) into soil-water systems can stimulate the decomposition of soil OC (SOC) via priming effects in temperate forests, shrublands, grasslands, and agro-ecosystems. However, priming effects are still not well understood in the field setting for temperate ecosystems and virtually nothing is known about priming effects (e.g., existence, frequency, and magnitude) in boreal ecosystems. In this study, a coupled dissolved OC (DOC) transport and microbial biomass dynamics model was developed to simultaneously simulate co-occurring hydrological, physical, and biological processes and their interactions in soil pore-water systems. The developed model was then used to examine the importance of priming effects in two black spruce forest soils, with and without underlying permafrost. Our simulations showed that priming effects were strongly controlled by the frequency and intensity of DOC input, with greater priming effects associated with greater DOC inputs. Sensitivity analyses indicated that priming effects were most sensitive to variations in the quality of SOC, followed by variations in microbial biomass dynamics (i.e., microbial death and maintenance respiration), highlighting the urgent need to better discern these key parameters in future experiments and to consider these dynamics in existing ecosystem models. Water movement carries DOC to deep soil layers that have high SOC stocks in boreal soils. Thus, greater priming effects were predicted for the site with favorable water movement than for the site with limited water flow, suggesting that priming effects might be accelerated for sites where permafrost degradation leads to the formation of dry thermokarst.     

Joint analysis of longitudinal data and recurrent episodes data with application to medical cost analysis

This paper discusses regression analysis of longitudinal data in which the observation process may be related to the longitudinal process of interest. Such data have recently attracted a great deal of attention and some methods have been developed. However, most of those methods treat the observation process as a recurrent event process, which assumes that one observation can immediately follow another. Sometimes, this is not the case, as there may be some delay or observation duration. Such a process is often referred to as a recurrent episode process. One example is the medical cost related to hospitalization, where each hospitalization serves as a single observation. For the problem, we present a joint analysis approach for regression analysis of both longitudinal and observation processes and a simulation study is conducted that assesses the finite sample performance of the approach. The asymptotic properties of the proposed estimates are also given and the method is applied to the medical cost data that motivated this study.     

okemon及其在肿瘤中的研究进展

Pokemon 基因即POK 红系髓性致癌因子，也被称为FBI -1 ，LRF ，OCZF ，TIP ，它是POK 转录抑制物家族成员之一，其编 码的产物具有BTB / POZ 域和锌指结构,它是第一个被发现的可变阅读框基因ARF ( Alternative reading frame ，ARF )的特异性 转录抑制物，Pokemon 通过特异抑制ARF 转录来调控细胞周期、诱导肿瘤发生、促进肿瘤的发生发展，在一些人类肿瘤如食管鳞 癌、肺癌、结肠癌、人贲门癌、膀胱癌，前列腺癌和乳腺癌等肿瘤组织中具有较高的表达水平。Pokemon 的特殊性在于还能与其它 癌基因如Bcl-2，MDM2 等结合之后发挥作用来促进其他癌基因的活性。因此可以认为Pokemon 是肿瘤的总开关，对Pokemon 基 因的进一步研究有助于为肿瘤的诊断和治疗提供新的途径和方法。