CRISPR-Cas9 system: a novel and promising era of genotherapy for beta-hemoglobinopathies, hematological malignancy, and hemophilia.

Gene therapy represents a significant potential to revolutionize the field of hematology with applications in correcting genetic mutations, generating cell lines and animal models, and improving the feasibility and efficacy of cancer immunotherapy. Compared to different genetic engineering tools, clustered regularly interspaced short palindromic repeats (CRISPR) CRISPR-associated protein 9 (Cas9) emerged as an effective and versatile genetic editor with the ability to precisely modify the genome. The applications of genetic engineering in various hematological disorders have shown encouraging results. Monogenic hematological disorders can conceivably be corrected with single gene modification. Through the use of CRISPR-CAS9, restoration of functional red blood cells and hemostasis factors were successfully attained in sickle cell anemia, beta-thalassemia, and hemophilia disorders. Our understanding of hemato-oncology has been advanced via CRIPSR-CAS9 technology. CRISPR-CAS9 aided to build a platform of mutated genes responsible for cell survival and proliferation in leukemia. Therapeutic application of CRISPR-CAS9 when combined with chimeric antigen receptor (CAR) T cell therapy in multiple myeloma and acute lymphoblastic leukemia was feasible with attenuation of CAR T cell therapy pitfalls. Our review outlines the latest literature on the utilization of CRISPR-Cas9 in the treatment of beta-hemoglobinopathies and hemophilia disorders. We present the strategies that were employed and the findings of preclinical and clinical trials. Also, the review will discuss gene engineering in the field of hemato-oncology as a proper tool to facilitate and overcome the drawbacks of chimeric antigen receptor T cell therapy (CAR-T).

Hematopoietic stem cell transplant does not prevent neurological deterioration in infants with Farber disease: Case report and literature review.

Farber disease (FD) is an inherited autosomal recessive disorder of lipid metabolism. The hallmark of the disease is systemic accumulation of ceramide due to lysosomal acid ceramidase deficiency. The involvement of the central nervous system is critical in this disorder leading to rapid deterioration and death within a few years after birth. Efforts to treat patients by hematopoietic stem cell transplant (HSCT) have resulted in favorable results in the absence of neurological manifestations. We report the outcomes of HSCT in two patients with FD who received early HSCT and had neurological deterioration posttransplant. We also present a new understanding of the limitations of HSCT in FD management based on our observations of the clinical course of the two patients after therapy.

Systemic ceramide accumulation leads to severe and varied pathological consequences.

Farber disease (FD) is a severe inherited disorder of lipid metabolism characterized by deficient lysosomal acid ceramidase (ACDase) activity, resulting in ceramide accumulation. Ceramide and metabolites have roles in cell apoptosis and proliferation. We introduced a single-nucleotide mutation identified in human FD patients into the murine Asah1 gene to generate the first model of systemic ACDase deficiency. Homozygous Asah1(P361R/P361R) animals showed ACDase defects, accumulated ceramide, demonstrated FD manifestations and died within 7-13 weeks. Mechanistically, MCP-1 levels were increased and tissues were replete with lipid-laden macrophages. Treatment of neonates with a single injection of human ACDase-encoding lentivector diminished the severity of the disease as highlighted by enhanced growth, decreased ceramide, lessened cellular infiltrations and increased lifespans. This model of ACDase deficiency offers insights into the pathophysiology of FD and the roles of ACDase, ceramide and related sphingolipids in cell signaling and growth, as well as facilitates the development of therapy.

Autologous transplantation of lentivector/acid ceramidase-transduced hematopoietic cells in nonhuman primates.

Farber disease is a rare lysosomal storage disorder (LSD) that manifests due to acid ceramidase (AC) deficiencies and ceramide accumulation. We present a preclinical gene therapy study for Farber disease employing a lentiviral vector (LV-huAC/huCD25) in three enzymatically normal nonhuman primates. Autologous, mobilized peripheral blood (PB) cells were transduced and infused into fully myelo-ablated recipients with tracking for at least 1 year. Outcomes were assessed by measuring the AC specific activity, ceramide levels, vector persistence/integration, and safety parameters. We observed no hematological, biochemical, radiological, or pathological abnormalities. Hematological recovery occurred by approximately 3 weeks. Vector persistence was observed in PB and bone marrow (BM) cells by qualitative and quantitative PCR. We did not observe any clonal proliferation of PB and BM cells. Importantly, AC-specific activity was detected above normal levels in PB and BM cells analyzed post-transplantation and in spleens and livers at the endpoint of the study. Decreases of ceramide in PB cells as well as in spleen and liver tissues were seen. We expect that this study will provide a roadmap for implementation of clinical gene therapy protocols targeting hematopoietic cells for Farber disease and other LSDs.