Introduction: Adjuvant trastuzumab is a standard of care in the treatment of Human Epidermal growth factor Receptor 2 (HER2) positive early breast cancer (eBC). Initially trastuzumab could only be administered intravenously (IV), however since 2013, a subcutaneous (SC) formulation with comparable efficacy and safety profile is available and preferred by patients. Trastuzumab SC does not require pharmacy preparation and has shorter administration time.
View Article and Find Full Text PDFGene expression circuitries, which enable cells to detect precise levels within a morphogen concentration gradient, have a pivotal impact on biological processes such as embryonic pattern formation, paracrine and autocrine signalling, and cellular migration. We present the rational synthesis of a synthetic genetic circuit exhibiting band-pass detection characteristics. The components, involving multiply linked mammalian trans-activator and -repressor control systems, were selected and fine-tuned to enable the detection of 'low-threshold' morphogen (tetracycline) concentrations, in which target gene expression was triggered, and a 'high-threshold' concentration, in which expression was muted.
View Article and Find Full Text PDFCircadian clocks have long been known to be essential for the maintenance of physiological and behavioral processes in a variety of organisms ranging from plants to humans. Dysfunctions that subvert gene expression of oscillatory circadian-clock components may result in severe pathologies, including tumors and metabolic disorders. While the underlying molecular mechanisms and dynamics of complex gene behavior are not fully understood, synthetic approaches have provided substantial insight into the operation of complex control circuits, including that of oscillatory networks.
View Article and Find Full Text PDFApplications of conditional gene expression, whether for therapeutic or basic research purposes, are increasingly requiring mammalian gene control systems that exhibit far tighter control properties. While numerous approaches have been used to improve the widely used Tet-regulatory system, many applications, particularly with respect to the engineering of synthetic gene networks, will require a broader range of tightly performing gene control systems. Here, a generically applicable approach is described that utilizes intronically encoded siRNA on the relevant transregulator construct, and siRNA sequence-specific tags on the reporter construct, to minimize basal gene activity in the off-state of a range of common gene control systems.
View Article and Find Full Text PDFWith the recent development of a wide range of inducible mammalian transgene control systems it has now become possible to create functional synthetic gene networks by linking and connecting systems into various configurations. The past 5 years has thus seen the design and construction of the first synthetic mammalian gene regulatory networks. These networks have built upon pioneering advances in prokaryotic synthetic networks and possess an impressive range of functionalities that will some day enable the engineering of sophisticated inter- and intra-cellular functions to become a reality.
View Article and Find Full Text PDFIncreases in our understanding of gene function have greatly expanded the repertoire of possible genetic interventions at our disposal with the consequence that many genetic engineering applications require multiple manipulations in which target genes can be both overexpressed and silenced in a simple and co-ordinated manner. Using synthetic introns as a source of encoding short-interfering RNA (siRNA), we demonstrate that it is possible to simultaneously express both a transgene and siRNA from a single polymerase (Pol) II promoter. By encoding siRNA as an intron between two protein domains requiring successful splicing for functionality, it was possible to demonstrate that splicing was occurring, that the coding genes (exonic transgenes) resulted in functional protein, and that the spliced siRNA-containing lariat was capable of modulating expression of a separate target gene.
View Article and Find Full Text PDFThe straightforward production and dose-controlled administration of protein therapeutics remain major challenges for the biopharmaceutical manufacturing and gene therapy communities. Transgenes linked to HIV-1-derived vpr and pol-based protease cleavage (PC) sequences were co-produced as chimeric fusion proteins in a lentivirus production setting, encapsidated and processed to fusion peptide-free native protein in pseudotyped lentivirions for intracellular delivery and therapeutic action in target cells. Devoid of viral genome sequences, protein-transducing nanoparticles (PTNs) enabled transient and dose-dependent delivery of therapeutic proteins at functional quantities into a variety of mammalian cells in the absence of host chromosome modifications.
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