Current Issue : January - March Volume : 2020 Issue Number : 1 Articles : 5 Articles
Pharmacotherapy as the mainstay in the management of breast cancer suffers from various\ndrawbacks, including non-targeted biodistribution, narrow therapeutic and safety windows, and\nalso resistance to treatment. Thus, alleviation of the constraints from the pharmacodynamic and\npharmacokinetic profile of classical anti-cancer drugs could lead to improvements in efficacy and\npatient survival in malignancies. Moreover, modifications in the genetic pathophysiology of cancer\nvia administration of small nucleic acids might pave the way towards higher response rates to\nchemotherapeutics. Inorganic pH-dependent carbonate apatite (CA) nanoparticles were utilized\nin this study to efficiently deliver various classes of therapeutics into cancer cells. Co-delivery of\ndrugs and genetic materials was successfully attained through a carbonate apatite delivery device.\nOn 4T1 cells, siRNAs against AKT and ERBB2 plus paclitaxel or docetaxel resulted in the largest\nincrease in anti-cancer effects compared to CA/paclitaxel or CA/docetaxel. Therefore, these ingredients\nwere selected for further in vivo investigations. Animals receiving injections of CA/paclitaxel or\nCA/docetaxel loaded with siRNAs against AKT and ERBB2 possessed significantly smaller tumors\ncompared toCA/drug-treated mice. Interestingly, synergistic interactions in target protein knock down\nwith combinations of CA/AKT/paclitaxel, CA/ERBB2/docetaxel were documented via western blotting....
CRISPR/Cas9 is a powerful tool for genome editing in cells and organisms. Nevertheless,\nintroducing directed templated changes by homology-directed repair (HDR) requires the cellular\nDNA repair machinery, such as the MRN complex (Mre11/Rad50/Nbs1). To improve the process,\nwe tailored chimeric constructs of Cas9, in which SpCas9 was fused at its N- or C-terminus to a\n126aa intrinsically disordered domain from HSV-1 alkaline nuclease (UL12) that recruits the MRN\ncomplex. The chimeric Cas9 constructs were two times more efficient in homology-directed editing of\nendogenous loci in tissue culture cells. This effect was dependent upon the MRN-recruiting activity\nof the domain and required lower amounts of the chimeric Cas9 in comparison with unmodified Cas9.\nThe new constructs improved the yield of edited cells when making endogenous point mutations\nor inserting small tags encoded by oligonucleotide donor DNA (ssODN), and also with larger\ninsertions encoded by plasmid DNA donor templates. Improved editing was achieved with both\ntransfected plasmid-encoded Cas9 constructs as well as recombinant Cas9 protein transfected as\nribonucleoprotein complexes. Our strategy was highly efficient in restoring a genetic defect in a cell\nline, exemplifying the possible implementation of our strategy in gene therapy. These constructs\nprovide a simple approach to improve directed editing....
We, and others, have previously achieved high and sustained levels of transgene expression\nfrom viral vectors, such as recombinant adeno-associated virus (rAAV). However, regulatable\ntransgene expression may be preferred in gene therapy for diseases, such as type 1 diabetes (T1D) and\nrheumatoid arthritis (RA), in which the timing and dosing of the therapeutic gene product play critical\nroles. In the present study, we generated a positive feedback regulation system for human alpha 1\nantitrypsin (hAAT) expression in the rAAV vector. We performed quantitative kinetics studies in vitro\nand in vivo demonstrating that this vector system can mediate high levels of inducible transgene\nexpression. Transgene induction could be tailored to occur rapidly or gradually, depending on the\ndose of the inducing drug, doxycycline (Dox). Conversely, after withdrawal of Dox, the silencing of\ntransgene expression occurred slowly over the course of several weeks. Importantly, rAAV delivery\nof inducible hAAT significantly prevented T1D development in non-obese diabetic (NOD) mice.\nThese results indicate that this Dox-inducible vector system may facilitate the fine-tuning of transgene\nexpression, particularly for hAAT treatment of human autoimmune diseases, including T1D....
Background: Transforming growth factor-Beta (TGF-Beta) plays a key role in bone metastasis\nformation; we hypothesized the possible involvement of TGF-Beta in the induction of cancer stem cells\n(CSCs) in the bone microenvironment (micro-E), which may be responsible for chemo-resistance.\nMethods: Mouse mammary tumor cells were implanted under the dorsal skin flap over the calvaria\nand into a subcutaneous (subQ) lesions in female mice, generating tumors in the bone and subQ\nmicro-Es. After implantation of the tumor cells, mice were treated with a TGF-Beta R1 kinase inhibitor\n(R1-Ki). Results: Treatment with R1-Ki decreased tumor volume and cell proliferation in the bone\nmicro-E, but not in the subQ micro-E. R1-Ki treatment did not affect the induction of necrosis\nor apoptosis in either bone or subQ micro-E. The number of cells positive for the CSC markers,\nSOX2, and CD166 in the bone micro-E, were significantly higher than those in the subQ micro-E.\nR1-Ki treatment significantly decreased the number of CSC marker positive cells in the bone\nmicro-E but not in the subQ micro-E. TGF-Beta activation of the MAPK/ERK and AKT pathways was\nthe underlying mechanism of cell proliferation in the bone micro-E. BMP signaling did not play a role\nin cell proliferation in either micro-E. Conclusion: Our results indicated that the bone micro-E is a key\nniche for CSC generation, and TGF-Beta signaling has important roles in generating CSCs and tumor\ncell proliferation in the bone micro-E. Therefore, it is critically important to evaluate responses to\nchemotherapeutic agents on both cancer stem cells and proliferating tumor cells in different tumor\nmicroenvironments in vivo....
Cataract is a leading cause of blindness worldwide. Currently, restoration of vision in\ncataract patients requires surgical removal of the cataract. Due to the large and increasing number\nof cataract patients, the annual cost of surgical cataract treatment amounts to billions of dollars.\nLimited access to functional human lens tissue during the early stages of cataract formation has\nhampered efforts to develop effective anti-cataract drugs. The ability of human pluripotent stem\n(PS) cells to make large numbers of normal or diseased human cell types raises the possibility that\nhuman PS cells may provide a new avenue for defining the molecular mechanisms responsible for\ndifferent types of human cataract. Towards this end, methods have been established to differentiate\nhuman PS cells into both lens cells and transparent, light-focusing human micro-lenses. Sensitive\nand quantitative assays to measure light transmittance and focusing ability of human PS cellderived\nmicro-lenses have also been developed. This review will, therefore, examine how human\nPS cell-derived lens cells and micro-lenses might provide a new avenue for development of muchneeded\ndrugs to treat human cataract....
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