Complementation of diverse HIV-1 Env defects through cooperative subunit interactions: a general property of the functional trimer

<p>Abstract</p> <p>Background</p> <p>The HIV-1 Env glycoprotein mediates virus entry by catalyzing direct fusion between the virion membrane and the target cell plasma membrane. Env is composed of two subunits: gp120, which binds to CD4 and the coreceptor, and gp41, which is triggered upon coreceptor binding to promote the membrane fusion reaction. Env on the surface of infected cells is a trimer consisting of three gp120/gp41 homo-dimeric protomers. An emerging question concerns cooperative interactions between the protomers in the trimer, and possible implications for Env function.</p> <p>Results</p> <p>We extended studies on cooperative subunit interactions within the HIV-1 Env trimer, using analysis of functional complementation between coexpressed inactive variants harboring different functional deficiencies. In assays of Env-mediated cell fusion, complementation was observed between variants with a wide range of defects in both the gp120 and gp41 subunits. The former included gp120 subunits mutated in the CD4 binding site or incapable of coreceptor interaction due either to mismatched specificity or V3 loop mutation. Defective gp41 variants included point mutations at different residues within the fusion peptide or heptad repeat regions, as well as constructs with modifications or deletions of the membrane proximal tryptophan-rich region or the transmembrane domain. Complementation required the defective variants to be coexpressed in the same cell. The observed complementation activities were highly dependent on the assay system. The most robust activities were obtained with a vaccinia virus-based expression and reporter gene activation assay for cell fusion. In an alternative system involving Env expression from integrated provirus, complementation was detected in cell fusion assays, but not in virus particle entry assays.</p> <p>Conclusion</p> <p>Our results indicate that Env function does not require every subunit in the trimer to be competent for all essential activities. Through cross-talk between subunits, the functional determinants on one defective protomer can cooperatively interact to trigger the functional determinants on an adjacent protomer(s) harboring a different defect, leading to fusion. Cooperative subunit interaction is a general feature of the Env trimer, based on complementation activities observed for a highly diverse range of functional defects.</p

Upregulation of CENP-H in tongue cancer correlates with poor prognosis and progression

<p>Abstract</p> <p>Background</p> <p>Centromere protein H (CENP-H) is one of the fundamental components of the human active kinetochore. Recently, CENP-H was identified to be associated with tumorigenesis. This study was aimed to investigate the clinicopathologic significance of CENP-H in tongue cancer.</p> <p>Methods</p> <p>RT-PCR, real time RT-PCR and Western blot were used to examine the expression of CENP-H in tongue cancer cell lines and biopsies. CENP-H protein level in paraffin-embedded tongue cancer tissues were tested by immunohistochemical staining and undergone statistical analysis. CENP-H-knockdown stable cell line was established by infecting cells with a retroviral vector pSuper-retro-CENP-H-siRNA. The biological function of CENP-H was tested by MTT assay, colony formation assay, and Bromodeoxyuridine (BrdU) incorporation assay.</p> <p>Results</p> <p>CENP-H expression was higher in tongue cancer cell lines and cancer tissues (T) than that in normal cell and adjacent noncancerous tongue tissues (N), respectively. It was overexpressed in 55.95% (94/168) of the paraffin-embedded tongue cancer tissues, and there was a strong correlation between CENP-H expression and clinical stage, as well as T classification. CENP-H can predict the prognosis of tongue cancer patients especially those in early stage. Depletion of CENP-H can inhibit the proliferation of tongue cancer cells (Tca8113) and downregulate the expression of Survivin.</p> <p>Conclusion</p> <p>These findings suggested that CENP-H involves in the development and progression of tongue cancer. CENP-H might be a valuable prognostic indicator for tongue cancer patients within early stage.</p

MicroRNA Dysregulation in the Spinal Cord following Traumatic Injury

Spinal cord injury (SCI) triggers a multitude of pathophysiological events that are tightly regulated by the expression levels of specific genes. Recent studies suggest that changes in gene expression following neural injury can result from the dysregulation of microRNAs, short non-coding RNA molecules that repress the translation of target mRNA. To understand the mechanisms underlying gene alterations following SCI, we analyzed the microRNA expression patterns at different time points following rat spinal cord injury

The changing landscape of phase II/III metastatic sarcoma clinical trials—analysis of ClinicalTrials.gov

Abstract Background Well-designed clinical trials are of great importance in validating novel treatments and ensuring an evidence-based approach for sarcoma. This study aimed to provide a comprehensive landscape of the characteristics of metastatic or advanced sarcoma clinical trials using the substantial resource of the ClincialTrials.gov database. Methods We identified 260,755 trials registered with ClinicalTrials.gov in the last 20 years, and 277 of them were eligible for inclusion. The baseline characteristics were ascertained for each trial. The trials were systematically reviewed to validate their classification into 96 trials registered before 2008 and 181 trials registered between 2008 and 2017. Results We found that in the last decade, metastatic and advanced sarcoma trials were predominantly phase II-III studies (p = 0.048), were more likely to be ≥2 arms (17.7% vs 35.3%, respectively; p = 0.007), and were more likely to use randomized (13.5% vs 30.4%; p = 0.002) and double-blinded (2.1% vs 9.4%; p = 0.024) assignment than trials registered before 2008. Furthermore, in the last 10-year period, metastatic sarcoma trials were more likely to be conducted in Asia. Treatment involving target therapy and immunotherapy were more common (71.8% vs 37.5%; p < 0.001) than in previous years. Conclusions Our data showed provocative changes in the sarcoma landscape and demonstrated that the incidence of clinical trials with target therapy and immunotherapy is increasing. These findings emphasize the desperate need for novel strategies, including target therapy and immunotherapy, to improve the outcomes for patients with advanced sarcoma

Neural activity associated with cognitive regulation in heroin users: A fMRI study

Previous research has found heroin addicts to be impulsive. This study employed functional magnetic resonance imaging technology to investigate the differences between heroin addicts and normal controls in neural activity associated with cognitive regulation of behavior. Twenty-one Chinese men participated in this study, 11 of whom were newly admitted heroin-addicted patients and 10 of whom were healthy volunteers. In the experimental task, the subjects were required to first identify the correct directions of arrowheads and then give the opposite answers. Behaviorally, the heroin-dependent patients took a much shorter time to complete the more demanding second part of the task but committed more errors than the normal controls. This pattern of behavior, characteristic of people who are disinhibited and who tend to be impulsive, was consistent with previous reports of impulsivity observed in people who have abused heroin. The neural activity of the patients that was associated with performing the experimental task of cognitive regulation was different to that of the normal controls in terms of the pattern of prefrontal activation, the attenuation of activity in the anterior cingulate, and the additional recruitment of the right inferior parietal region. This study is the first that seeks to understand the neural activity associated with impulsive behavior in people who abuse heroin. The pattern of imaging data obtained resembled the pattern of data observed in immature brains attempting to exercise cognitive control of behavior. Further theoretical and clinical implications of the findings are discussed. © 2005 Elsevier Ireland Ltd. All rights reserved.link_to_subscribed_fulltex

Fluorescent-based single-strand conformation polymorphism/heteroduplex capillary electrophoretic mutation analysis of the p53 gene

Fluorescent-based single-strand conformation polymorphism (F-SSCP) analysis with capillary electrophoresis (CE) is the most common method for the detection of mutation because of its high sensitivity and resolution. In this study, we prepared an inexpensive linear polyacrylamide (LPA), and successfully applied it to CE-SSCP analysis and tandem CESSCP/heteroduplex analysis (HA) of the P53 gene on an ABI capillary genetic analyzer. A comparison of the sieving capabilities of a homemade LPA and commercial polydimethylacrylamide (PDMA) demonstrates that the homemade LPA has a higher resolution, a shorter analysis time, and is more suitable for tandem SSCP/HA than commercial PDMA. To show the usefulness, mutations of P53 gene exon 7 - 8 in 37 tumor samples were investigated by using homemade LPA. The results indicate that 10 mutations were found in 9 of 37 cases; the majority of P53 mutations were missense mutations, and 70% were located in exon 7, which plays an important role in neoplastic progression in human tumorigenesis

A favorable outcome of advanced dermatofibrosarcoma protuberans under treatment with sunitinib after imatinib failure

Wei Xiao,1,2 Yi Que,1,2 Ruiqing Peng,1,2 Ya Ding,1,2 Jingjing Zhao,1,2 Xizhi Wen,1,2 Desheng Weng,1,2 Xiaoshi Zhang,1,2 Yuanxiang Guan,2,3,* Xing Zhang1,2,* 1Melanoma and Sarcoma Medical Oncology Unit, Sun Yat-sen University Cancer Center, Guangzhou, People&rsquo;s Republic of China; 2State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, People&rsquo;s Republic of China; 3Department of Gastric Surgery, Sun Yat-sen University Cancer Center, Guangzhou, People&rsquo;s Republic of China *These authors equally contributed to the work Abstract: While traditional cytotoxic agents play a limited role in advanced dermatofibrosarcoma protuberans (DFSP), the treatment of sunitinib for patients with advanced DFSP after imatinib failure is not well defined. The objective of this case report was to analyze the relationship between molecular mechanisms and clinical outcomes of sunitinib treatment in patients with advanced DFSP after imatinib failure. In this case report, a 37-year-old man suffered from advanced DFSP progression after surgical operation, microwave ablation, and chemotherapy. The immunohistochemistry in this patient revealed abundant expression of platelet-derived growth factor receptor-beta on tumor cells, which is one of the drug targets of sunitinib. The nucleotide sequence analysis revealed COL1A1-PDGFB fusion transcripts in this patient. Thus, we treated the patient with sunitinib, a multi-targeted tyrosine kinase inhibitor, after imatinib failure. After treatment with sunitinib, the patient exhibited a partial response and 9 months&rsquo; progression-free survival without significant adverse drug effects. In our case, the patient with advanced DFSP experienced a favorable outcome in 9-months&rsquo; progression-free survival and a significant improvement of quality of life without serious side effects after sunitinib treatment. Therefore, sunitinib could serve as another treatment option for patients with advanced DFSP. Keywords: COL1A1-PDGFB fusion gene, dermatofibrosarcoma protuberans, platelet-derived growth factor receptor-beta, sunitini

A pilot study of functional magnetic resonance imaging of the brain during manual and electroacupuncture stimulation of acupuncture point (LI-4 Hegu) in normal subjects reveals differential brain activation between methods

Objectives: To characterize the brain activation patterns evoked by manual and electroacupuncture on normal human subjects.Design: We used functional magnetic resonance imaging (fMRI) to investigate the brain regions involved in electroacupuncture and manual acupuncture needle stimulation. A block design was adopted for the study. Each functional run consists of 5 minutes, starting with 1-minute baseline and two 1-minute stimulation, the interval between the two stimuli was 1 minute. Four functional runs were performed on each subject, two runs for electroacupuncture and two runs for manual acupuncture. The order of the two modalities was randomized among subjects. During the experiment, acupuncture needle manipulation was performed at Large Intestine 4 (LI4, Hegu) on the left hand. For each subject, before scanning started, the needle was inserted perpendicular to the skin surface to a depth of approximately 1.0 cm. Electroacupuncture stimulation was delivered using a continuous rectangular wave form (pulse width 30 ms) at a frequency of 3 Hz. For manual acupuncture, the needle was rotated manually clockwise and counterclockwise at a rate of about 180 times per minute (3 Hz).Subjects: Eleven right-handed, normal, healthy volunteer adults, 6 male and 5 female, ages 21-64 participated in the experiment.Results: Results showed that electroacupuncture mainly produced fMRI signal increases in precentral gyrus, postcentral gyrus/inferior parietal lobule, and putamen/insula; in contrast, manual needle manipulation produced prominent decreases of fMRI signals in posterior cingulate, superior temporal gyrus, putamen/insula.Conclusion: These results indicate that different brain networks are involved during manual and electroacupuncture stimulation. It suggests that different brain mechanisms may be recruited during manual and electroacupuncture.Objectives: To characterize the brain activation patterns evoked by manual and electroacupuncture on normal human subjects