38 research outputs found
Specific DNA-RNA Hybrid Recognition by TAL Effectors
SummaryThe transcription activator-like (TAL) effector targets specific host promoter through its central DNA-binding domain, which comprises multiple tandem repeats (TALE repeats). Recent structural analyses revealed that the TALE repeats form a superhelical structure that tracks along the forward strand of the DNA duplex. Here, we demonstrate that TALE repeats specifically recognize a DNA-RNA hybrid where the DNA strand determines the binding specificity. The crystal structure of a designed TALE in complex with the DNA-RNA hybrid was determined at a resolution of 2.5 Å. Although TALE repeats are in direct contact with only the DNA strand, the phosphodiester backbone of the RNA strand is inaccessible by macromolecules such as RNases. Consistent with this observation, sequence-specific recognition of an HIV-derived DNA-RNA hybrid by an engineered TALE efficiently blocked RNase H-mediated degradation of the RNA strand. Our study broadens the utility of TALE repeats and suggests potential applications in processes involving DNA replication and retroviral infections
Photoredox-catalyzed reaction as a powerful tool for rapid natural product Gem -dimethylation modification: discovery of potent anti-cancer agents with improved druggability
Tylophorine has diverse biological activities; however, the stability, solubility, and central nervous system toxicity have severely limited use of tylophorine. The gem -dimethyl group is an organic chemistry functional group that consists of two methyl groups bonded to the same carbon atom. This feature has gained significant attention in medicinal chemistry due to its unique properties and potential applications in drug design. We applied a new photoredox methodology to tylophorine modification, resulting in a series of gem-dimethyl tylophorine analogues. Among the analogues, compound 4b demonstrated promising activity against a wide range of tumor cell lines and exhibited significantly improved drug-like properties, including enhanced solubility and stability. Compound 4b showed an exceptional inhibitory effect (7.8 nM) against a C481S mutation-induced ibrutinib-resistant non-Hodgkin’s lymphoma cell line, as well as primary tumor cell lines obtained from patients. Importantly, compound 4b exhibited significantly reduced anti-proliferative activity against the normal cell line tested, indicating the potential for an enhanced therapeutic window for compound 4b . Based on these early-stage data, we believe that our study provides a solid foundation for the development of new therapeutic agents for potential drug-resistant cancer treatment in the near future
A Magnetic Bead-Integrated Chip for the Large Scale Manufacture of Normalized esiRNAs
The chemically-synthesized siRNA duplex has become a powerful and widely used tool for RNAi loss-of-function studies, but suffers from a high off-target effect problem. Recently, endoribonulease-prepared siRNA (esiRNA) has been shown to be an attractive alternative due to its lower off-target effect and cost effectiveness. However, the current manufacturing method for esiRNA is complicated, mainly in regards to purification and normalization on a large-scale level. In this study, we present a magnetic bead-integrated chip that can immobilize amplification or transcription products on beads and accomplish transcription, digestion, normalization and purification in a robust and convenient manner. This chip is equipped to manufacture ready-to-use esiRNAs on a large-scale level. Silencing specificity and efficiency of these esiRNAs were validated at the transcriptional, translational and functional levels. Manufacture of several normalized esiRNAs in a single well, including those silencing PARP1 and BRCA1, was successfully achieved, and the esiRNAs were subsequently utilized to effectively investigate their synergistic effect on cell viability. A small esiRNA library targeting 68 tyrosine kinase genes was constructed for a loss-of-function study, and four genes were identified in regulating the migration capability of Hela cells. We believe that this approach provides a more robust and cost-effective choice for manufacturing esiRNAs than current approaches, and therefore these heterogeneous RNA strands may have utility in most intensive and extensive applications
Engineered Maturation Approaches of Human Pluripotent Stem Cell-Derived Ventricular Cardiomyocytes
Heart diseases such as myocardial infarction and myocardial ischemia are paroxysmal and fatal in clinical practice. Cardiomyocytes (CMs) differentiated from human pluripotent stem cells provide a promising approach to myocardium regeneration therapy. Identifying the maturity level of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) is currently the main challenge for pathophysiology and therapeutics. In this review, we describe current maturity indicators for cardiac microtissue and microdevice cultivation technologies that accelerate cardiac maturation. It may provide insights into regenerative medicine, drug cardiotoxicity testing, and preclinical safety testing
Integration of Cancer Gene Co-expression Network and Metabolic Network To Uncover Potential Cancer Drug Targets
Cell metabolism is critical for cancer
cell transformation and
progression. In this study, we have developed a novel method, named
Met-express, that integrates a cancer gene co-expression network with
the metabolic network to predict key enzyme-coding genes and metabolites
in cancer cell metabolism. Met-express successfully identified a group
of key enzyme-coding genes and metabolites in lung, leukemia, and
breast cancers. Literature reviews suggest that approximately 33–53%
of the predicted genes are either known or suggested anti-cancer drug
targets, while 22% of the predicted metabolites are known or high-potential
drug compounds in therapeutic use. Furthermore, experimental validations
prove that 90% of the selected genes and 70% of metabolites demonstrate
the significant anti-cancer phenotypes in cancer cells, implying that
they may play important roles in cancer metabolism. Therefore, Met-express
is a powerful tool for uncovering novel therapeutic biomarkers
Integration of Cancer Gene Co-expression Network and Metabolic Network To Uncover Potential Cancer Drug Targets
Cell metabolism is critical for cancer
cell transformation and
progression. In this study, we have developed a novel method, named
Met-express, that integrates a cancer gene co-expression network with
the metabolic network to predict key enzyme-coding genes and metabolites
in cancer cell metabolism. Met-express successfully identified a group
of key enzyme-coding genes and metabolites in lung, leukemia, and
breast cancers. Literature reviews suggest that approximately 33–53%
of the predicted genes are either known or suggested anti-cancer drug
targets, while 22% of the predicted metabolites are known or high-potential
drug compounds in therapeutic use. Furthermore, experimental validations
prove that 90% of the selected genes and 70% of metabolites demonstrate
the significant anti-cancer phenotypes in cancer cells, implying that
they may play important roles in cancer metabolism. Therefore, Met-express
is a powerful tool for uncovering novel therapeutic biomarkers
Integration of Cancer Gene Co-expression Network and Metabolic Network To Uncover Potential Cancer Drug Targets
Cell metabolism is critical for cancer
cell transformation and
progression. In this study, we have developed a novel method, named
Met-express, that integrates a cancer gene co-expression network with
the metabolic network to predict key enzyme-coding genes and metabolites
in cancer cell metabolism. Met-express successfully identified a group
of key enzyme-coding genes and metabolites in lung, leukemia, and
breast cancers. Literature reviews suggest that approximately 33–53%
of the predicted genes are either known or suggested anti-cancer drug
targets, while 22% of the predicted metabolites are known or high-potential
drug compounds in therapeutic use. Furthermore, experimental validations
prove that 90% of the selected genes and 70% of metabolites demonstrate
the significant anti-cancer phenotypes in cancer cells, implying that
they may play important roles in cancer metabolism. Therefore, Met-express
is a powerful tool for uncovering novel therapeutic biomarkers
MicroRNAs Targeting Nox2
Copyright © 2017 by the American Physiological Society.DOI: 10.1152/ajpheart.00685.2016Myocardial infarction (MI) is the most common cause of heart failure. Excessive production of reactive oxygen species plays a key role in the pathogenesis of cardiac remodeling after MI. NADPH with Nox2 as the catalytic subunit is a major source of superoxide production and expression is significantly increased in the infarcted myocardium, especially by infiltrating macrophages. While microRNAs (miRNAs) are potent regulators of gene expression, and play an important role in heart disease, there still lacks efficient ways to identify miRNAs that target important pathological genes for treating MI. Thus, the overall objective was to establish a miRNA screening and delivery system for improving heart function after MI using Nox2 as a critical target
Barcoded Microchips for Biomolecular Assays
Multiplexed
assay of analytes is of great importance for clinical
diagnostics and other analytical applications. Barcode-based bioassays
with the ability to encode and decode may realize this goal in a straightforward
and consistent manner. We present here a microfluidic barcoded chip
containing several sets of microchannels with different widths, imitating
the commonly used barcode. A single barcoded microchip can carry out
tens of individual protein/nucleic acid assays (encode) and immediately
yield all assay results by a portable barcode reader or a smartphone
(decode). The applicability of a barcoded microchip is demonstrated
by human immunodeficiency virus (HIV) immunoassays for simultaneous
detection of three targets (anti-gp41 antibody, anti-gp120 antibody,
and anti-gp36 antibody) from six human serum samples. We can also
determine seven pathogen-specific oligonucleotides by a single chip
containing both positive and negative controls