TUSC1, a Putative Tumor Suppressor Gene,Reduces Tumor Cell Growth In Vitro and Tumor Growth In Vivo

We previously reported the identification of TUSC1 (Tumor Suppressor Candidate 1), as a novel intronless gene isolated from a region of homozygous deletion at D9S126 on chromosome 9p in human lung cancer. In this study, we examine the differential expression of TUSC1 in human lung cancer cell lines by western blot and in a primary human lung cancer tissue microarray by immunohistochemical analysis. We also tested the functional activities and mechanisms of TUSC1 as a tumor suppressor gene through growth suppression in vitro and in vivo. The results showed no expression of TUSC1 in TUSC1 homozygously deleted cells and diminished expression in some tumor cell lines without TUSC1 deletion. Interestingly, the results from a primary human lung cancer tissue microarray suggested that higher expression of TUSC1 was correlated with increased survival times for lung cancer patients. Our data demonstrated that growth curves of tumor cell lines transfected with TUSC1 grew slower in vitro than those transfected with the empty vector. More importantly, xenograph tumors in nude mice grew significantly slower in vivo in cells stably transfected with TUSC1 than those transfected with empty vector. In addition, results from confocal microscopy and immunohistochemical analyses show distribution of TUSC1 in the cytoplasm and nucleus in tumor cell lines and in normal and tumor cells in the lung cancer tissue microarray. Taken together, our results support TUSC1 has tumor suppressor activity as a candidate tumor suppressor gene located on chromosome 9p.     

Splicing of a cap-proximal human Papillomavirus 16 E6E7 intron promotes E7 expression, but can be restrained by distance of the intron from its RNA 5' cap

Human papillomavirus 16 (HPV16) E6E7 pre-mRNA is bicistronic and has an intron in the E6 coding region with one 5' splice site and two alternative 3' splice sites, which produce E6(*)I and E6(*)II, respectively. If this intron remains unspliced, the resulting E6E7 mRNA expresses oncogenic E6. We found for the first time that the E6E7 pre-mRNA was efficiently spliced in vitro only when capped and that cellular cap-binding factors were involved in the splicing. The cap-dependent splicing of the E6E7 pre-mRNA was extremely efficient in cervical cancer-derived cells, producing mostly E6(*)I, but inefficient in cells transfected with a common retrovirus expression vector, pLXSN16E6E7, due to the large size of this vector's exon 1. Further studies showed that efficient splicing of the E6E7 pre-mRNA depends on the distance of the cap-proximal intron from the RNA 5' cap, with an optimal distance of less than 307nt in order to facilitate better association of U1 small nuclear RNA with the intron 5' splice site. The same was true for splicing of human beta-globin RNA. Splicing of the E6E7 RNA provided more E7 RNA templates and promoted E7 translation, whereas a lack of RNA splicing produced a low level of E7 translation. Together, our data indicate that the distance between the RNA 5' cap and cap-proximal intron is rate limiting for RNA splicing. HPV16 E6E7 pre-mRNA takes advantage of its small cap-proximal exon to confer efficient splicing for better E7 expression.     

Cytokine Profile in Human Eyes: Contribution of a New Cytokine Combination for Differential Diagnosis between Intraocular Lymphoma or Uveitis

Primary intraocular lymphoma (PIOL), also called primary vitreoretinal lymphomas, often masquerades as uveitis. This misdiagnosis can result in subsequent brain involvement and oculocerebral lymphoma (OCL). In this study, we sought to characterize the helper T-cell type 1 (Th1)/Th2 cytokine profile in vitreous samples from patients with PIOL, OCL, uveitis and controls with non-inflammatory disease. Vitreous and aqueous humor samples from 87 patients with PIOL (n = 30), OCL (n = 12), uveitis (n = 34), and retinal detachment (RD) without hemorrhage (n = 11) were analyzed and their concentrations of interleukin (IL)-2, IL-4, IL-6, IL-10, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α were determined by flow cytometric bead arrays (CBA). The IL-10 levels determined by CBA were compared with those by ELISA. IL-10 concentrations measured by CBA and ELISA were highly correlated. IL-2, IL-4, and TNFα were not detected in any sample. The only cytokine detected at a significant level in samples from RD vitreous was IL-6. The IL-10/IL-6 ratio, as previously reported, was slightly higher in PIOL than in uveitis samples, but not for all patients. Cytokine profiles from PIOL and OCL samples did not differ. The combination of the IL-10/IL-6 and IL-10/IFNγ ratios was highly informative for discriminating PIOL/OCL from uveitis samples and for therapeutic follow up of PIOL. This strategy might be very helpful as an initial screening to rule out PIOL in patients thought to have uveitis.     

Fluid–structure interaction (FSI) simulation for studying the impact of atherosclerosis on hemodynamics,arterial tissue remodeling,and initiation risk of intracranial aneurysms

The biomechanical and hemodynamic effects of atherosclerosis on the initiation of intracranial aneurysms (IA) are not yet clearly discovered. Also, studies for the observation of hemodynamic variation due to atherosclerotic stenosis and its impact on arterial remodeling and aneurysm genesis remain a controversial field of vascular engineering. The majority of studies performed are relevant to computational fluid dynamic (CFD) simulations. CFD studies are limited in consideration of blood and arterial tissue interactions. In this work, the interaction of the blood and vessel tissue because of atherosclerotic occlusions is studied by developing a fluid and structure interaction (FSI) analysis for the first time. The FSI presents a semi-realistic simulation environment to observe how the blood and vessels' structural interactions can increase the accuracy of the biomechanical study results. In the first step, many different intracranial vessels are modeled for an investigation of the biomechanical and hemodynamic effects of atherosclerosis in arterial tissue remodeling. Three physiological conditions of an intact artery, the artery with intracranial atherosclerosis (ICAS), and an atherosclerotic aneurysm (ACA) are employed in the models with required assumptions. Finally, the obtained outputs are studied with comparative and statistical analyses according to the intact model in a normal physiological condition. The results show that existing occlusions in the cross-sectional area of the arteries play a determinative role in changing the hemodynamic behavior of the arterial segments. The undesirable variations in blood velocity and pressure throughout the vessels increase the risk of arterial tissue remodeling and aneurysm formation.

     

Regulatory T cells control uveoretinitis induced by pathogenic Th1 cells reacting to a specific retinal neoantigen

In many clinical cases, uveitis develops secondary to an infection. This could result from peripheral activation followed by ocular penetration and reactivation of T cells specific for microbial Ags expressed in the retina. To gain insights into the pathophysiology of uveitis, we developed a new mouse model based on stable retinal expression of influenza virus hemagglutinin (HA) neoantigen by adeno-associated virus-mediated gene transfer. One month thereafter, we adoptively transferred HA-specific T cells, which were activated in vitro or in vivo. Intraocular inflammation was clinically and histologically observed in all animals within 15 days. The ocular infiltrate was composed mostly of macrophages and HA-specific T cells with a proinflammatory cytokine profile. Depletion of CD4(+)CD25(+) regulatory T cells exacerbated the disease, whereas HA-specific CD4(+)CD25(+) T cells given i.v. controlled the disease. This novel model should allow to better study the pathophysiology and therapeutic of uveitis.     

Finite element modeling of shape memory polyurethane foams for treatment of cerebral aneurysms

In this paper, a thermo-mechanical analysis of shape memory polyurethane foams (SMPUFs) with aiding of a finite element model (FEM) for treating cerebral aneurysms (CAs) is introduced. Since the deformation of foam cells is extremely difficult to observe experimentally due to their small size, a structural cell-assembly model is established in this work via finite element modeling to examine all-level deformation details. Representative volume elements of random equilateral Kelvin open-cell microstructures are adopted for the cell foam. Also, a user-defined material subroutine (UMAT) is developed based on a thermo-visco-elastic constitutive model for SMPUFs, and implemented in the ABAQUS software package. The model is able to capture thermo-mechanical responses of SMPUFs for a full shape memory thermodynamic cycle. One of the latest treatments of CAs is filling the inside of aneurysms with SMPUFs. The developed FEM is conducted on patient-specific basilar aneurysms treated by SMPUFs. Three sizes of foams are selected for the filling inside of the aneurysm and then governing boundary conditions and loadings are applied to the foams. The results of the distribution of stress and displacement in the absence and presence of the foam are compared. Due to the absence of similar results in the specialized literature, this paper is likely to fill a gap in the state of the art of this problem and provide pertinent results that are instrumental in the design of SMPUFs for treating CAs.