73 research outputs found
Characteristics of AU-rich elements and involvement of the poly-(A) tail in stress-induced mRNA stabilization
[no abstract
GLUT 5 Is Not Over-Expressed in Breast Cancer Cells and Patient Breast Cancer Tissues
F18 2-Fluoro 2-deoxyglucose (FDG) has been the gold standard in positron emission tomography (PET) oncologic imaging since its introduction into the clinics several years ago. Seeking to complement FDG in the diagnosis of breast cancer using radio labeled fructose based analogs, we investigated the expression of the chief fructose transporter-GLUT 5 in breast cancer cells and human tissues. Our results indicate that GLUT 5 is not over-expressed in breast cancer tissues as assessed by an extensive immunohistochemistry study. RT-PCR studies showed that the GLUT 5 mRNA was present at minimal amounts in breast cancer cell lines. Further knocking down the expression of GLUT 5 in breast cancer cells using RNA interference did not affect the fructose uptake in these cell lines. Taken together these results are consistent with GLUT 5 not being essential for fructose uptake in breast cancer cells and tissues
Imaging Target mRNA and siRNA-Mediated Gene Silencing In Vivo with Ribozyme-Based Reporters
Noninvasive imaging of specific mRNAs in living subjects promises numerous biological and medical applications. Common strategies use fluorescently or radioactively labelled antisense probes to detect target mRNAs through a hybridization mechanism, but have met with limited success in living animals. Herewe present a novel molecular imaging approach based on the group I intron of Tetrahymena thermophila for imaging mRNA molecules in vivo. Engineered trans-splicing ribozyme reporters contain three domains, each of which is designed for targeting, splicing, and reporting. They can transduce the target mRNA into a reporter mRNA, leading to the production of reporter enzymes that can be noninvasively imaged in vivo. We have demonstrated this ribozyme-mediated RNA imaging method for imaging a mutant p53 mRNA both in single cells and noninvasively in living mice. After optimization, the ribozyme reporter increases contrast for the transiently expressed target by 180-fold, and by ten-fold for the stably expressed target. siRNA-mediated specific gene silencingof p53 expression has been successfully imaged in real time in vivo. This newribozyme-ba sed RNA reporter system should open up newavenues for in vivo RNA imaging and direct imaging of siRNA inhibition
Maltotriose-based probes for fluorescence and photoacoustic imaging of bacterial infections
AbstractCurrently, there are no non-invasive tools to accurately diagnose wound and surgical site infections before they become systemic or cause significant anatomical damage. Fluorescence and photoacoustic imaging are cost-effective imaging modalities that can be used to noninvasively diagnose bacterial infections when paired with a molecularly targeted infection imaging agent. Here, we develop a fluorescent derivative of maltotriose (Cy7-1-maltotriose), which is shown to be taken up in a variety of gram-positive and gram-negative bacterial strains in vitro. In vivo fluorescence and photoacoustic imaging studies highlight the ability of this probe to detect infection, assess infection burden, and visualize the effectiveness of antibiotic treatment in E. coli-induced myositis and a clinically relevant S. aureus wound infection murine model. In addition, we show that maltotriose is an ideal scaffold for infection imaging agents encompassing better pharmacokinetic properties and in vivo stability than other maltodextrins (e.g. maltohexose).</jats:p
Alternative medicine: therapeutic effects on gastric original signet ring carcinoma via ascorbate and combination with sodium alpha lipoate
Abstract
Background
Gastric signet ring cell carcinoma (SRCC) is an aggressive gastric adenocarcinoma with a poor prognosis when diagnosed at an advanced stage. As alternative medicine, two natural supplements (ascorbate (AA) and sodium alpha lipoate (LA)) have been shown to inhibit various cancers with mild side effects.
Methods
These two natural supplements and a series of combinations (AA&LA, AA+LA and LA + AA) were incubated with non-SRCC cells (GPM-1), patient-derived gastric origin SRCC (GPM-2), gastric-origin SRCCs (HSC-39 and KATO-3), human pancreatic (MIA PaCa-2) and ovarian (SKOV-3) cells for evaluating their therapeutic effects. Moreover, these treatments were applied in 3D-cultured organoids to reveal the feasibility of these approaches for in vivo study.
Results
Analyzing their antioxidant capabilities and dose-response curves, we observed that all four gastric cell lines, including three patient-derived cell lines were sensitive to ascorbate (~ 10 mM). The influence of ascorbate incubation time was studied, with a 16-h incubation found to be optimal for in vitro studies. Moreover, a simultaneous combination of AA and LA (AA&LA) did not significantly inhibit cell proliferation, while prior LA treatment increased the growth inhibition of AA therapy (LA + AA). Anti-cancer efficacy of AA was further confirmed in 3D-cultured SRCC (KATO-3) organoids.
Conclusions
This study highlights the potential of AA and LA + AA in treating gastric origin SRCC, and demonstrates the influence of order in which the drugs are administered.
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Imaging Target mRNA and siRNA-Mediated Gene Silencing In Vivo with Ribozyme-Based Reporters
Synthesis and Characterization of 9-(4-[18F]Fluoro-3-(hydroxymethyl)butyl)-2-(phenylthio)-6-oxopurine as a Novel PET Agent for Mutant Herpes Simplex Virus Type 1 Thymidine Kinase Reporter Gene Imaging
Positron Emission Tomography of (64)Cu-DOTA-Rituximab in a Transgenic Mouse Model Expressing Human CD20 for Clinical Translation to Image NHL
Positron emission tomography reporter gene strategy for use in the central nervous system
Significance
With any new treatment it is imperative the medical community has a way to monitor its effectiveness, tracking its location, monitoring its expression, and observing off-target effects. Gene/cell therapy is no exception. The growing number of studies creates a need to monitor them more accurately. A number of PET reporter gene systems have been reported; however, they have limitations, including regions of high endogenous gene expression in the central nervous system (CNS), low specificity, or endogenous expression of the reporter gene in microglia. One of these systems has been used in the clinical setting; however, its associated imaging agent lacks blood–brain barrier penetration. Our approach aims to overcome these limitations and facilitate monitoring of gene/cell therapy in the CNS.</jats:p
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