Browsing by Subject "EXPRESSION"

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    A comparative analysis of EGFR-targeting antibodies for gold nanoparticle CT imaging of lung cancer.
    (PloS one, 2018-01) Ashton, Jeffrey R; Gottlin, Elizabeth B; Patz, Edward F; West, Jennifer L; Badea, Cristian T
    Computed tomography (CT) is the standard imaging test used for the screening and assessment of suspected lung cancer, but distinguishing malignant from benign nodules by CT is an ongoing challenge. Consequently, a large number of avoidable invasive procedures are performed on patients with benign nodules in order to exclude malignancy. Improving cancer discrimination by non-invasive imaging could reduce the need for invasive diagnostics. In this work we focus on developing a gold nanoparticle contrast agent that targets the epidermal growth factor receptor (EGFR), which is expressed on the cell surface of most lung adenocarcinomas. Three different contrast agents were compared for their tumor targeting effectiveness: non-targeted nanoparticles, nanoparticles conjugated with full-sized anti-EGFR antibodies (cetuximab), and nanoparticles conjugated with a single-domain llama-derived anti-EGFR antibody, which is smaller than the cetuximab, but has a lower binding affinity. Nanoparticle targeting effectiveness was evaluated in vitro by EGFR-binding assays and in cell culture with A431 cells, which highly express EGFR. In vivo CT imaging performance was evaluated in both C57BL/6 mice and in nude mice with A431 subcutaneous tumors. The cetuximab nanoparticles had a significantly shorter blood residence time than either the non-targeted or the single-domain antibody nanoparticles. All of the nanoparticle contrast agents demonstrated tumor accumulation; however, the cetuximab-targeted group had significantly higher tumor gold accumulation than the other two groups, which were statistically indistinguishable from one another. In this study we found that the relative binding affinity of the targeting ligands had more of an effect on tumor accumulation than the circulation half life of the nanoparticles. This study provides useful insight into targeted nanoparticle design and demonstrates that nanoparticle contrast agents can be used to detect tumor receptor overexpression. Combining receptor status data with traditional imaging characteristics has the potential for better differentiation of malignant lung tumors from benign lesions.
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    Comparison of the molecular properties of retinitis pigmentosa P23H and N15S amino acid replacements in rhodopsin.
    (PloS one, 2019-01) Mitchell, James; Balem, Fernanda; Tirupula, Kalyan; Man, David; Dhiman, Harpreet Kaur; Yanamala, Naveena; Ollesch, Julian; Planas-Iglesias, Joan; Jennings, Barbara J; Gerwert, Klaus; Iannaccone, Alessandro; Klein-Seetharaman, Judith
    Mutations in the RHO gene encoding for the visual pigment protein, rhodopsin, are among the most common cause of autosomal dominant retinitis pigmentosa (ADRP). Previous studies of ADRP mutations in different domains of rhodopsin have indicated that changes that lead to more instability in rhodopsin structure are responsible for more severe disease in patients. Here, we further test this hypothesis by comparing side-by-side and therefore quantitatively two RHO mutations, N15S and P23H, both located in the N-terminal intradiscal domain. The in vitro biochemical properties of these two rhodopsin proteins, expressed in stably transfected tetracycline-inducible HEK293S cells, their UV-visible absorption, their Fourier transform infrared, circular dichroism and Metarhodopsin II fluorescence spectroscopy properties were characterized. As compared to the severely impaired P23H molecular function, N15S is only slightly defective in structure and stability. We propose that the molecular basis for these structural differences lies in the greater distance of the N15 residue as compared to P23 with respect to the predicted rhodopsin folding core. As described previously for WT rhodopsin, addition of the cytoplasmic allosteric modulator chlorin e6 stabilizes especially the P23H protein, suggesting that chlorin e6 may be generally beneficial in the rescue of those ADRP rhodopsin proteins whose stability is affected by amino acid replacement.
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    Fundamental frequency and intensity mean and variability before and after two behavioral treatments for aprosodia
    (Journal of Medical Speech-Language Pathology, 2009-03-01) Jones, HN; Shrivastav, R; Wu, SS; Plowman-Prine, EK; Rosenbek, JC
    Emerging data suggest that aprosodia may be amenable to behavioral treatment. This study investigated the use of acoustic analysis of speech to quantify response to two speech treatments previously judged to have an effect based on perceptual assessment in three participants with primarily expressive aprosodia. The mean and variability of fundamental frequency (F0) and intensity (INT) during production of sentences requiring use of four different emotional tones of speech (i.e., happy, angry, sad, or neutral) was calculated before and after two mechanism-based treatments for aprosodia (i.e., TX1 and TX2). Statistical differences in F0 mean and variability were primarily observed following TX1, whereas differences in INT mean and variability were principally revealed following TX2. Additionally, significant differences in these acoustic values were noted across almost all pairwise comparisons of emotional sentence types (i.e., angry vs. sad, happy vs. sad, neutral vs. sad, angry vs. neutral, and happy vs. neutral). These preliminary data suggest that perceptual improvements in aprosodia can be measured quantitatively using acoustic analysis of speech and provide additional support for previously described behavioral treatments for this disorder. These findings also support previous reports that suggest that different emotional tones of speech are associated with differences in the acoustic speech signal. Copyright © 2009 Delmar Cengage Learning.
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    Microgravity induces proteomics changes involved in endoplasmic reticulum stress and mitochondrial protection.
    (Scientific reports, 2016-09-27) Feger, Bryan J; Thompson, J Will; Dubois, Laura G; Kommaddi, Reddy P; Foster, Matthew W; Mishra, Rajashree; Shenoy, Sudha K; Shibata, Yoichiro; Kidane, Yared H; Moseley, M Arthur; Carnell, Lisa S; Bowles, Dawn E
    On Earth, biological systems have evolved in response to environmental stressors, interactions dictated by physical forces that include gravity. The absence of gravity is an extreme stressor and the impact of its absence on biological systems is ill-defined. Astronauts who have spent extended time under conditions of minimal gravity (microgravity) experience an array of biological alterations, including perturbations in cardiovascular function. We hypothesized that physiological perturbations in cardiac function in microgravity may be a consequence of alterations in molecular and organellar dynamics within the cellular milieu of cardiomyocytes. We used a combination of mass spectrometry-based approaches to compare the relative abundance and turnover rates of 848 and 196 proteins, respectively, in rat neonatal cardiomyocytes exposed to simulated microgravity or normal gravity. Gene functional enrichment analysis of these data suggested that the protein content and function of the mitochondria, ribosomes, and endoplasmic reticulum were differentially modulated in microgravity. We confirmed experimentally that in microgravity protein synthesis was decreased while apoptosis, cell viability, and protein degradation were largely unaffected. These data support our conclusion that in microgravity cardiomyocytes attempt to maintain mitochondrial homeostasis at the expense of protein synthesis. The overall response to this stress may culminate in cardiac muscle atrophy.
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    The effects of depression and use of antidepressive medicines during pregnancy on the methylation status of the IGF2 imprinted control regions in the offspring.
    (Clinical epigenetics, 2011-10-26) Soubry, A; Murphy, Sk; Huang, Z; Murtha, A; Schildkraut, Jm; Jirtle, Rl; Wang, F; Kurtzberg, J; Demark-Wahnefried, W; Forman, Mr; Hoyo, C
    In utero exposures to environmental factors may result in persistent epigenetic modifications affecting normal development and susceptibility to chronic diseases in later life. We explored the relationship between exposure of the growing fetus to maternal depression or antidepressants and DNA methylation at two differentially methylated regions (DMRs) of the imprinted Insulin-like Growth Factor 2 (IGF2) gene. Aberrant DNA methylation at the IGF2 and neighboring H19 DMRs has been associated with deregulated IGF2 expression, childhood cancers and several chronic diseases during adulthood. Our study population is comprised of pregnant mothers and their newborns (n = 436), as part of the Newborn Epigenetics Study (NEST). A standardized questionnaire was completed and medical record data were abstracted to ascertain maternal depression and antidepressive drug use. DMR methylation levels in umbilical cord blood leukocytes were quantified using pyrosequencing. From the 436 newborns, laboratory data were obtained for 356 individuals at the IGF2 DMRs, and for 411 individuals at the H19 DMRs; about half of each group was African American or Caucasian. While overall no association between depression and methylation profiles was found, we observed a significant hypermethylation of the H19 DMRs in newborns of African American (n = 177) but not Caucasian (n = 168) mothers who reported the use of antidepressive drugs during pregnancy (β = +6.89, p = 0.01). Of note, our data reveal a race-independent association between smoking during pregnancy and methylation at the IGF2 DMR (+3.05%, p = 0.01). In conclusion, our findings suggest a race-dependent response related to maternal use of antidepressants at one of the IGF2 DMRs in the offspring.
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    Therapeutic potential of ReACp53 targeting mutant p53 protein in CRPC.
    (Prostate cancer and prostatic diseases, 2020-03) Zhang, Yaqun; Xu, Lingfan; Chang, Yan; Li, YanJing; Butler, William; Jin, Er; Wang, Aifen; Tao, Yulei; Chen, Xufeng; Liang, Chaozhao; Huang, Jiaoti
    BACKGROUNDS:p53 is a tumor suppressor that prevents cancer onset and progression, and mutations in the p53 gene cause loss of the tumor suppressor function of the protein. The mutant p53 protein in tumor cells can form aggregates which contribute to the dominant-negative effect over the wild-type p53 protein, causing loss of p53 tumor suppression or gain of novel oncogenic functions. Mutations in p53 have been implicated in the pathogenesis of primary prostate cancer (PCa), and are often detected in recurrent and metastatic disease. Thus, targeting mutant p53 may constitute an alternative therapeutic strategy for advanced PCa for which there are no other viable options. METHODS:In this study, we used immunoprecipitation, immunofluorescence, clonogenic survival, and cell proliferation assays, flow cytometric analysis and in vivo xenograft to investigate the biological effects of ReACp53, a cell-permeable peptide inhibitor of p53 aggregation, on mutant p53-carrying PCa cells. RESULTS:Our results show that ReACp53 targets amyloid aggregates of mutant p53 protein and restores the p53 nuclear function as transcriptional factor, induces mitochondrial cell death and reduces DNA synthesis of mutant p53-carrying PCa cells; ReACp53 also inhibits xenograft tumor growth in vivo. CONCLUSIONS:The data presented here suggest a therapeutic potential of targeting mutant p53 protein in advanced PCa setting, which has a clinical impact for aggressive PCa with transforming how such tumors are managed.