Mononuclear cells from peripheral blood of thalassemic patients were treated with morpholino oligonucleotides antisense to aberrant splice sites in mutant β-globin precursor mRNAs (pre-mRNAs). The oligonucleotides restored correct splicing and translation of β-globin mRNA, increasing the hemoglobin (Hb) A synthesis in erythroid cells from patients with IVS2–654/β E , IVS2–745/IVS2–745, and IVS2–745/IVS2–1 genotypes. The maximal Hb A level for repaired IVS2–745 mutation was ≈30% of normal; Hb A was still detectable 9 days after a single treatment with oligonucleotide. Thus, expression of defective β-globin genes was repaired and significant level of Hb A was restored in a cell population that would be targeted in clinical applications of this approach.
11 August 2020 in Accreditation and Quality Assurance
Nowadays, Quality Management tools such as failure mode and effect analysis (FMEA) are widely used throughout the aeronautical, automotive, software, food services, health care and many other industries to sustain and improve quality and safety. The increasing complexity of scientific research makes it more difficult to maintain all activities under control, in order to guarantee validity and reproducibility of results. Even in non-regulated research, scientists need to be supported with management tools that maximize study performance and outcomes, while facilitating the research process. Frequently, steps that involve human intervention are the weak links in the process. Risk analysis therefore gives considerable benefit to analytical validation, assessing and avoiding failures due to human error, potential imprecision in applying protocols, uncertainty in equipment function and imperfect control of materials. This paper describes in detail how FMEA methodology can be applied as a performance improvement tool in the field of non-regulated research, specifically on a basic Life Sciences research process. We chose as “pilot process” the selection of oligonucleotide aptamers for therapeutic purposes, as an example of a complex and multi-step process, suitable for technology transfer. We applied FMEA methodology, seeking every opportunity for error and its impact on process output, and then, a set of improvement actions was generated covering most aspects of laboratory practice, such as equipment management and staff training. We also propose a useful tool supporting the risk assessment of research processes and its outputs and that we named “FMEA strip worksheet.” These tools can help scientists working in non-regulated research to approach Quality Management and to perform risk evaluation of key scientific procedures and processes with the final aim to increase and better control efficiency and efficacy of their research.
19 December 2003 in British Journal of Haematology
The British Journal of Haematology publishes original research papers in clinical, laboratory and experimental haematology. The Journal also features annotations, reviews, short reports, images in haematology and Letters to the Editor.
Correct human β-globin mRNA has been restored in erythroid cells from transgenic mice carrying the human gene with β-globin IVS2–654 splice mutation and from thalassemia patients with the IVS2–654/βE genotype. This was accomplished in a dose- and time-dependent manner by free uptake of morpholino oligonucleotide antisense to the aberrant splice site at position 652 of intron 2 in β-globin pre-mRNA. Under optimal conditions of oligonucleotide uptake, the maximal levels of correct human β-globin mRNA and hemoglobin A in patients9 erythroid cells were 77 and 54%, respectively. These levels of correction were equal to, if not higher than, those obtained by syringe loading of the oligonucleotide into the cells. Comparison of splicing correction results with the cellular uptake of fluorescein-labeled oligonucleotide indicated that the levels of mRNA and hemoglobin A correlate well with the nuclear localization of the oligonucleotide and the degree of erythroid differentiation of cultured cells. Similar but not as pronounced results were obtained after the oligonucleotide treatment of bone marrow cells from IVS2–654 mouse. The effectiveness of the free antisense morpholino oligonucleotide in restoration of correct splicing of IVS2–654 pre-mRNA in cultured erythropoietic cells from transgenic mice and thalassemic patients suggests the applicability of this or similar compounds in in vivo experiments and possibly in treatment of thalassemia.
20 May 2015 in Accreditation and Quality Assurance
Mutations at nucleotides 654, 705, or 745 in intron 2 of the human beta-globin gene activate aberrant 3' and 5' splice sites within the intron and prevent correct splicing of beta-globin pre-mRNA, resulting in inhibition of beta-globin synthesis and in consequence beta-thalassemia. Transfection of HeLa cells expressing the 3 thalassemic mutants with modified U7 snRNA (U7.623), containing a sequence antisense to a region between the aberrant splice sites, reduced the incorrect splicing of pre-mRNA and led to increased levels of the correctly spliced beta-globin mRNA and protein. A lentiviral vector carrying the U7.623 gene was effective in restoration of correct splicing in the model cell lines for at least 6 months. Importantly, the therapeutic value of this system was demonstrated in hematopoietic stem cells and erythroid progenitor cells from a patient with IVS2-745/IVS2-1 thalassemia. Twelve days after transduction of the patient cells with the U7.623 lentiviral vector, the levels of correctly spliced beta-globin mRNA and hemoglobin A were approximately 25-fold over background. These results should be regarded as a proof of principle for lentiviral vector-based gene therapy for beta-thalassemia.