Base editors: development and applications in biomedicine / 医学前沿

Base editor (BE) is a gene-editing tool developed by combining the CRISPR/Cas system with an individual deaminase, enabling precise single-base substitution in DNA or RNA without generating a DNA double-strand break (DSB) or requiring donor DNA templates in living cells. Base editors offer more precise and secure genome-editing effects than other conventional artificial nuclease systems, such as CRISPR/Cas9, as the DSB induced by Cas9 will cause severe damage to the genome. Thus, base editors have important applications in the field of biomedicine, including gene function investigation, directed protein evolution, genetic lineage tracing, disease modeling, and gene therapy. Since the development of the two main base editors, cytosine base editors (CBEs) and adenine base editors (ABEs), scientists have developed more than 100 optimized base editors with improved editing efficiency, precision, specificity, targeting scope, and capacity to be delivered in vivo, greatly enhancing their application potential in biomedicine. Here, we review the recent development of base editors, summarize their applications in the biomedical field, and discuss future perspectives and challenges for therapeutic applications.

Recent studies on dilated cardiomyopathy caused by TTN mutations in children / 中国当代儿科杂志

The mutations of TTN gene that encodes titin are the most common mutation type among the genetic causes of dilated cardiomyopathy (DCM). This article reviews the worldwide studies on potential molecular pathogenesis (transcription, post-translational modification, etc.), clinical phenotypes, and gene therapies of pediatric DCM caused by TTN mutations, with the hope of providing a reference for the precision treatment of pediatric DCM caused by TTN mutations.

Therapeutics in paediatric genetic diseases: Current and future landscape

There are more than 7,000 paediatric genetic diseases (PGDs) but less than 5% have treatment options. Treatment strategies targeting different levels of the biological process of the disease have led to optimal health outcomes in a subset of patients with PGDs, where treatment is available. In the past 3 decades, there has been rapid advancement in the development of novel therapies, including gene therapy, for many PGDs. The therapeutic success of treatment relies heavily on knowledge of the genetic basis and the disease mechanism. Specifically, gene therapy has been shown to be effective in various clinical trials, and indeed, these trials have led to regulatory approvals, paving the way for gene therapies for other types of PGDs. In this review, we provide an overview of the treatment strategies and focus on some of the recent advancements in therapeutics for PGDs.

Terapia genética de injeção intravítrea de rAAV2-ND4 para neuropatia óptica hereditária de Leber: uma revisão sistemática / rAAV2-ND4 intravitreal injection gene therapy for Leber's hereditary optic neuropathy: a systematic review

RESUMO A neuropatia óptica hereditária de Leber é uma doença mitocondrial hereditária neurodegenerativa. A taxa potencial de recuperação espontânea é controversa na literatura. A terapia genética tem sido estudada como suporte aos pacientes. O objetivo desta revisão foi avaliar qualitativamente a segurança, os efeitos adversos e a eficácia da terapia gênica disponível. Trata-se de uma revisão sistemática de artigos indexados nas bases de dados PubMed®, Biblioteca Virtual em Saúde, SciELO, Cochrane, ScienceDirect, Scopus e Lilacs no primeiro semestre de 2021. Os critérios de inclusão e filtros foram: artigos relacionados ao tema, estudos randomizados, ensaios clínicos, trabalhos em humanos, últimos 5 anos, nas línguas portuguesa, inglesa e espanhola e texto completo disponível gratuitamente. Os parâmetros de exclusão foram: artigos duplicados, fuga ao tema, artigos de revisão, trabalhos não disponíveis e que fugiam aos critérios de inclusão. O coeficiente de kappa foi 0,812. A terapia não apresentou efeitos adversos sérios em nenhum dos artigos selecionados, e os efeitos menores sofreram 100% de remissão espontânea após o tratamento. Apesar de NAbs terem sido encontrados no soro de alguns pacientes, não houve associação entre a resposta imune adaptativa e a injeção do vetor viral. O tratamento foi eficaz na melhora da acuidade e campo visual. Vários estudos confirmaram a eficácia da terapia gênica, em doses baixas e médias, na melhora da acuidade visual e também sobre os efeitos adversos comuns relacionados à altas doses. A resposta imune humoral e a variação dos NAbs no soro foi citada em mais de um artigo. A terapia foi eficaz na melhora da acuidade visual e os efeitos adversos que surgiram foram tratados facilmente. No entanto, a resposta imune humoral ainda precisa ser estudada.

ABSTRACT Leber's Hereditary Optic Neuropathy (LHON) is an inherited neurodegenerative mitochondrial disease. The potential rate of spontaneous recovery is controversial in the literature. Gene therapy has been studied to support patients. The objective of this review was to qualitatively assess the safety, adverse effects, and efficacy of available gene therapy. This is a systematic review of articles indexed in PubMed®, VHL, SciELO, Cochrane, ScienceDirect, Scopus, and Lilacs databases, in the first half of 2021. Inclusion criteria and filters were: articles related to the topic, randomized studies, clinical trials, work in humans, last 5 years, in Portuguese, English, and Spanish and full text available for free. The exclusion parameters were: duplicate articles, not related to the topic, review articles, not available works, and works that did not meet the inclusion criteria. The kappa coefficient was 0.812. The therapy had no serious adverse effects in any of the selected articles, and minor effects experienced 100% spontaneous remission after treatment. Although NAbs were found in the serum of some patients, there was no association between the adaptive immune response and the injection of the viral vector. The treatment was effective in improving acuity and visual field. Several studies have confirmed the effectiveness of gene therapy, at low and medium doses, in improving visual acuity and also on common adverse effects related to high doses. The humoral immune response and the variation in serum NAbs was cited in more than one article. The therapy was effective in improving visual acuity and the adverse effects that arose were easily treated. However, the humoral immune response still needs to be studied.

Antibióticos innovadores contra la farmacorresistencia bacteriana obtenido por tecnología de edición genética CRISPR/Cas9 / Innovative antibiotics against bacterial drug resistance obtained by CRISPR/cas9 gene editing technology

Introducción: El aumento de la resistencia a los antimicrobianos constituye actualmente una peligrosa amenaza para la salud. Ante este problema global de falta de antimicrobianos, es perentorio intervenir de forma coordinada e idear fórmulas para incentivar la investigación a nivel internacional. Objetivo: Realizar una revisión actualizada sobre las causas y mecanismos de la resistencia a los antibióticos y la adaptación del sistema CRISPR/Cas para el desarrollo de innovadores antimicrobianos como parte esencial de una estrategia altamente específica en el tratamiento de infecciones producidas por bacterias resistentes. Métodos: Se realizó una revisión documental, se empleó la bibliografía nacional e internacional especializada publicada en los últimos 5 años. Se utilizó el motor de búsqueda Google Académico y se consultaron artículos de libre acceso en las bases de datos Pubmed, SciELO, LILACS, CUMED y HINARI, en el período comprendido entre marzo de 2020 hasta el mes de enero de 2021. Se revisaron un total de 41 artículos. Las consultas se hicieron en inglés y español. Para la búsqueda se tuvo en cuenta las palabras clave: eligobióticos; resistencia a antibióticos; CRISPR/Cas. Resultados: La evidencia recopilada sustenta que muchas enfermedades son inducidas por alteraciones del equilibrio de la microbiota humana y la técnica de edición genética CRISPR/Cas permitirá el desarrollo de novedosos antibióticos como los eligobióticos que eliminarán las bacterias patógenas multirresistentes y dejarán intacto el microbioma. Conclusiones: el esclarecimiento de los enigmas de la microbiota y su diseño con terapia génica permitirán el progreso de innovadores antibióticos con empleo del sistema CRISPR/Cas que ineludiblemente modificarán la práctica médica para siempre(AU)

Introduction: The increase in antimicrobial resistance is currently a dangerous threat to health. Faced with this global problem of lack of antimicrobials, it is imperative to intervene in a coordinated manner and devise formulas to encourage research at the international level. Objective: To review on the update causes and mechanisms of antibiotic resistance and the adaptation of CRISPR/Cas system for the development of innovative antimicrobials as an essential part of a highly specific strategy in the treatment of infections caused by resistant bacteria. Methods: A documentary review was carried out in the specialized national and international bibliography published in the last 5 years. Google Scholar search engine was used and free access articles were consulted in Pubmed, SciELO, LILACS, CUMED and HINARI databases, from March 2020 to January 2021. A total of 41 articles were retrieved. The consultations were made in English and Spanish. For the search, we took into account the keywords eligobiotics, antibiotic resistance, CRISPR/Cas. Results: The reviewed evidence supports that many diseases are induced by alterations in the balance of the human microbiota; and CRISPR/Cas gene editing technique will allow the development of novel antibiotics such as eligobiotics that will eliminate multi-resistant pathogenic bacteria and leave the microbiome intact. Conclusions: The clarification of the enigmas of the microbiota and its design with gene therapy will allow the progress of innovative antibiotics using CRISPR/Cas system that will inevitably change medical practice forever(AU)

Farmacoterapia da atrofia muscular espinhal / Pharmacotherapy of spinal muscular atrophy

Realizar uma revisão bibliográfica sobre os medicamentos específicos empregados no tratamento da Atrofia Muscular Espinhal (AME), uma doença genética neurodegenerativa caracterizada por fraqueza nos membros e atrofia muscular. Revisão narrativa de literatura, realizada por meio de um estudo descritivo, com abordagem qualitativa, baseada em estudos por meio de uma seleção classificatória de pesquisas sobre a farmacoterapia da AME. Os fármacos aprovados para o tratamento da AME fazem parte do arsenal da terapia gênica: nusinersena, onasemnogeno abeparvoveque e risdiplam. Com exceção do onasemnogeno abeparvoveque, utilizado em dose única, os demais devem ser utilizados pelo resto da vida. Todos eles, de maneiras distintas, elevam os níveis da proteína SMN (sobrevivência do neurônio motor), cuja deficiência leva à morte dos neurônios motores, causando aos sintomas progressivos da AME. Estes medicamentos apresentam custo elevado e são pouco acessíveis, sendo que apenas o nusinersena é disponibilizado pelo SUS. No momento as alternativas de tratamento farmacológico são escassas e de difícil acesso e a cura, apesar dos esforços da ciência, ainda está distante da realidade. No entanto, a terapia gênica se mostra como um diferencial para o tratamento e controle da AME, representando uma inovação e esperança para os pacientes com esta doença

Nanobubbles: A Novel Targeted Drug Delivery System

Abstract Nanobubbles are nanometer size bubbles having different constituents of varying physicochemical characteristic for the inner core and outer shell. Nanobubbles are mainly fabricated to improve the stability, bioavailability and improve the biodistribution of the delivered drug to the specific targeted site. Their small sizes bubbles allow the possibility of extravasation from blood vessels into the surrounding tissues and ultrasound-targeted site-specific release with minimal invasiveness. Nanobubbles are developing as important contrast agents for imaging and carriers for drug delivery at targeted region. Sonication is the primary method for preparation of nanobubbles followed by thin-layer evaporation, high shear emulsification, mechanical agitation and coacervation or coalescence. With exposure to ultrasound/extracorporeal shock waves, the drug is liberated from the nanobubbles into the target cells. This review paper is an effort to reveal the different formulation development techniques briefly and varying shell and core content for developing nanobubbles.

Optimization of β-globin Stable Expression Using the Third Generation Lentiviral Vector for β-thalassemia Therapy / 中国实验血液学杂志

OBJECTIVE@#To provide a research basis for a safe and effective cell therapy for β-thalassemia through optimization of HS4 region of the third generation lentiviral vector for stable expression of β-globin.@*METHODS@#The human β-globin HS4 region in the third generation lentiviral expression vector was optimized to construct the lenti-HBB, and the transcription and translation of β-globin gene were analyzed by RT-PCR and Western blot after the transduction of lenti-HBB in MEL cell line. Furthermore, the erythroid differentiation of CD34+ cells which were transduced lentiviral virus carrying human β-globin from normal human umbilical cord blood cells and peripheral blood cells of patients with β-thalassemia major were confirmed by colony formation assay, cell smear assay and flow cytometry. The safety and effectiveness of the optimized lenti-HBB were verified by NSG mouse in vivo test.@*RESULTS@#The human β-globin was expressed stably in the MEL cells, and CD34+ cells from health umbilical cord blood as well as PBMC from patient with β-thalassemia major transduced with lenti-HBB could be differentiated to mature red blood cells. The β-globin expression and differentiation in CD34+ cells were demonstrated successfully in the NSG mouse for about 35 months after post-transplant.@*CONCLUSION@#Stable β-globin expression through the optimization of HS4 from CD34+ in the third generation lentiviral vector is safe and effective for patients with severe β-thalassemia and other β-globin abnormal diseases.

O estado da arte das síndromes autoinflamatórias associadas à criopirina / The state of the art of cryopyrin-associated periodic syndromes

As síndromes autoinflamatórias associadas à criopirina (CAPS) compreendem um grupo espectral de doenças raras autoinflamatórias. Todas estas doenças estão relacionadas ao inflamassoma NLRP3, sendo que de 50-60% dos pacientes apresentam mutações ao longo do gene NLRP3. Clinicamente, febre recorrente associada à urticária neutrofílica e outros sintomas sistêmicos são o grande marco clínico, comum a todo o espectro. O bloqueio da interleucina-1 trouxe grande alívio ao tratamento destas desordens, mas variações na resposta clínica podem ser observadas, principalmente nos espectros mais graves. Neste trabalho os autores trazem uma revisão do estado da arte das doenças autoinflamatórias CAPS. Foi realizado levantamento de literatura e, ao final, 49 artigos restaram como base para construção do texto final. O trabalho traz de forma narrativa os principais pontos relacionados a imunofisiopatologia, manifestação clínica, diagnóstico, tratamento, complicações e novas armas diagnósticas, e terapia gênica.

Cryopyrin-associated periodic syndromes (CAPS) comprise a spectrum of rare autoinflammatory disorders. They are all related to the NLRP3 inflammasome, and 50-60% of the patients harbor mutations along the NLRP3 gene. Clinically, recurrent fever associated with neutrophilic urticaria and other systemic symptoms are a hallmark of all the disorders in the spectrum. Biologic drugs that can block interleukin-1 were a milestone for the treatment of such rare diseases, although variability in clinical response to this therapeutic intervention were observed, especially in those affected by severe phenotypes. In this paper, the authors provide a state-of-the-art review of CAPS. A literature search was performed and, finally, 49 articles remained for the construction of the final manuscript. The article presents a narrative review focused on the topics related to immune pathophysiology, clinical manifestations, diagnosis, treatment, complications and new therapeutic options, and gene therapy.

Limitations and advances in new treatments and future perspectives of corneal blindness / Limitações e avanços em novos tratamentos e perspectivas futuras na cegueira corneal

ABSTRACT This review is intended to describe the therapeutic approaches for corneal blindness, detailing the steps and elements involved in corneal wound healing. It also presents the limitations of the actual surgical and pharmacological strategies used to restore and maintain corneal transparency in terms of long-term survival and geographic coverage. In addition, we critically review the perspectives of anabolic agents, including vitamin A, hormones, growth factors, and novel promitotic and anti-inflammatory modulators, to assist corneal wound healing. We discuss the studies involving nanotechnology, gene therapy, and tissue reengineering as potential future strategies to work solely or in combination with corneal surgery to prevent or revert corneal blindness.(AU)

RESUMO O presente trabalho traz uma revisão das abordagens terapêuticas para a cegueira da córnea. O estudo detalha as etapas e os elementos envolvidos na cicatrização da córnea. Ele mostra as limitações das estratégias cirúrgicas e farmacológicas usadas para restaurar e manter a transparência da córnea em termos de sobrevida a longo prazo e alcance geográfico. As perspectivas dos agentes anabólicos, incluindo vitamina A, hormônios, fatores de crescimento e novos moduladores pró-mitóticos e anti-inflamatórios para auxiliar a cicatrização da ferida na córnea, são revisadas criticamente. Aqui, apresentamos estudos envolvendo nanotecnologia, terapia gênica e reengenharia de tecidos como possíveis estratégias futuras para atuar de maneira isolada ou combinada com a cirurgia da córnea para prevenir ou reverter a cegueira corneana.(AU)

Leucemia linfoide crónica: aspectos citogenéticos y moleculares / Chronic Lymphoid Leukemia: cytogenetic and molecular aspects

Introducción: La leucemia linfoide crónica es un trastorno linfoproliferativo caracterizado por la acumulación de linfocitos pequeños de aspecto maduro en sangre periférica, médula ósea y tejidos linfoides con un período de vida prolongado. Presenta una gran variabilidad clínica y genética. Objetivo: Describir los aspectos citogenéticos y moleculares de la leucemia linfoide crónica. Métodos: Se realizó revisión de la literatura en inglés y español, a través del sitio web PubMed y el motor de búsqueda Google académico, de artículos publicados en los últimos 5 años. Se hizo un análisis y resumen de la bibliografía revisada. Desarrollo: En la leucemia linfoide crónica están presentes alteraciones citogenéticas frecuentes como la deleción de los cromosomas 13q, 11q y 17p, así como la trisomía 12, que unido al conocimiento del estado mutacional del gen de la región variable de la cadena pesada de la inmunoglobulina, y otras mutaciones somáticas en diferentes genes, así como a variables clínicas y de laboratorio permiten la estratificación pronóstica de los pacientes. Conclusiones: El diagnóstico a través de los estudios citogenéticos convencionales estimulados con mitógenos, la hibridación in situ por fluorescencia y la secuenciación génica permite una mayor comprensión de la biología de la enfermedad, así como tomar decisiones terapéuticas más personalizadas(AU)

Introduction: Chronic B lymphoid leukemia is a lymphoproliferative disorder characterized by the accumulation of small, mature-looking lymphocytes in peripheral blood, bone marrow and lymphoid tissues with a long life span. It has great clinical and genetic variability. Objective: To describe the cytogenetic and molecular aspects of the disease. Methods: A review of the literature in English and in Spanish was carried out, in the PubMed website and using the search engine of Google Scholar, for articles published in the last five years. We performed analysis and summary of the reviewed bibliography. Development: In chronic lymphoid leukemia, frequent cytogenetic alterations are present such as deletion of chromosomes 13q, 11q and 17p, as well as trisomy 12, which together with the knowledge of the mutational status of the gene for the variable region of the immunoglobulin heavy chain and other somatic mutations in different genes, as well as clinical and laboratory variables allows prognostic stratification of patients. Conclusions: Diagnosis through conventional mitogen-stimulated cytogenetic studies, fluorescence in situ hybridization and gene sequencing allow a better understanding of the biology of the disease, as well as making more personalized therapeutic decisions(AU)

Treatment of patients with immunodeficiency: Medication, gene therapy, and transplantation

Abstract Objectives: To provide an overview of drug treatment, transplantation, and gene therapy for patients with primary immunodeficiencies. Source of data: Non-systematic review of the literature in the English language carried out at PubMed. Synthesis of data: The treatment of patients with primary immunodeficiencies aims to control their disease, especially the treatment and prevention of infections through antibiotic prophylaxis and/or immunoglobulin replacement therapy. In several diseases, it is possible to use specific medications for the affected pathway with control of the condition, especially in autoimmune or autoinflammatory processes associated with inborn immunity errors. In some diseases, treatment can be curative through hematopoietic stem cell transplantation (HSCT); more recently, gene therapy has opened new horizons through new technologies. Conclusions: Immunoglobulin replacement therapy remains the main therapeutic tool. Precision medicine with specific drugs for altered immune pathways is already a reality for several immune defects. Advances in the management of HSCT and gene therapy have expanded the capacity for curative treatments in patients with primary immunodeficiencies.

Global publication trends in ophthalmic genetics and gene therapy research: A Scientometric analysis / Tendências globais de publicação de pesquisas sobre genética oftálmica e terapia genética: uma análise cientométrica

ABSTRACT Objective: A scientometric analysis produced in ophthalmic genetics and gene therapy research is lacking. The purpose of this study is to present a holistic analysis of ophthalmic genetics literature. Methods: The data used in this study were obtained from the Web of Science (WoS) Core Collection. All published documents between 1975-2019 were included. The data exported from WoS enabled the extensive details of ophthalmic genetics related literature including countries, institutions, authors, citations and keywords. Scientometric network maps of keywords and also country and institution co-authorships were created with free software. Global contributions of the countries to the ophthalmic genetics literature were shown by a graphic. Results: The search query revealed a total of 2322 documents. Most of the documents were original articles (75.75%). USA was the leading country by producing 45.39% of all documents in ophthalmic genetics research followed by UK, Germany, China and France. Pennsylvania University was the most contributing institution in the literature (5.25%) followed by University College London and Moorfields Eye Hospital. The average citations per item was 29.4. The most used keywords over a 40-year period were 'family', 'cell', 'photoreceptor' and 'expression'. Conclusions: USA and UK dominated the ophthalmic genetics research. A substantial increase in the number of published documents in this field were observed after 2010.

RESUMO Objetivo: A literatura carece de análise cienciométrica produzida em genética oftálmica e de pesquisa em terapia genética. O objetivo deste estudo é apresentar uma análise holística da literatura genética oftálmica. Métodos: Os dados utilizados neste estudo foram obtidos na base de dados Web of Science (WoS) Core Collection. Todos os documentos publicados entre 1975 e 2019 foram incluídos na análise. Os dados exportados da WoS viabilizaram acesso a amplos detalhes da literatura relacionada à genética oftálmica, incluindo países, instituições, autores, citações e palavras-chave. Mapas de rede cienciométrica foram criados por meio de software gratuito, com base em palavras-chave e em coautorias de países e instituições. As contribuições globais dos países para a literatura sobre genética oftálmica foram apresentadas em gráfico. Resultados: a busca por pesquisas revelou um total de 2.322 documentos cuja maioria eram artigos originais (75,75%). Os EUA foram o país que mais produziu artigos sobre o tema, com 45,39% de todos os documentos em pesquisa genética oftálmica; ele foi seguido pelo Reino Unido, Alemanha, China e França. A Universidade da Pensilvânia foi a instituição que mais contribuiu para a literatura (5,25%), e foi seguida pela University College London e pelo Moorfields Eye Hospital. A média de citações por item foi de 29,4. As palavras-chave mais usadas em um período de 40 anos foram 'família', 'célula', 'fotorreceptor' e 'expressão'. Conclusões: Os EUA e o Reino Unido dominaram a pesquisa em genética oftálmica. Após 2010, observou-se um aumento substancial no número de documentos publicados nessa área.

CRISPR-Cas, el editor de genes / CRISPR, gene editor

El término CRISPR, por su acrónimo en inglés refiere a Clustered Regularly Interspaced Short Palindromic Repeats, es decir, repeticiones palindrómicas cortas, agrupadas y regularmente esparcidas, por sus características en el genoma, pertenece naturalmente al sistema de defensa de bacterias y arqueas. Este ha sido adaptado biotecnológicamente para la edición del ADN de células eucariotas, incluso de células humanas. El sistema CRISPR-Cas para editar genes consta, en forma generalizada, de dos componentes: una proteína nucleasa (Cas) y un ARN guía (sgRNA). La simplicidad del complejo lo hace una herramienta molecular reprogramable capaz de ser dirigida y de editar cualquier sitio en un genoma conocido. Su principal foco son las terapias para enfermedades hereditarias monogénicas y para el cáncer. Sin embargo, además de editor de genes, la tecnología CRISPR se utiliza para edición epigenética, regulación de la expresión génica y método de diagnóstico molecular. Este artículo tiene por objetivo presentar una revisión de las aplicaciones de la herramienta molecular CRISPR-Cas, particularmente en el campo biomédico, posibles tratamientos y diagnósticos, y los avances en investigación clínica, utilizando terapia génica con CRISPR/Cas más relevantes hasta la fecha. (AU)

CRISPR are Clustered Regularly Interspaced Short Palindromic Repeats, which naturally belong to the defense system of bacteria and archaea. It has been biotechnologically adapted for editing the DNA of eukaryotic cells, including human cells. The CRISPR-Cas system for editing genes generally consists of two components, a nuclease protein (Cas) and a guide RNA (sgRNA). The simplicity of the complex makes it a reprogrammable molecular tool capable of being targeted and editing any site in a known genome. Its main focus is therapies for monogenic inherited diseases and cancer. However, in addition to gene editor, CRISPR technology is used for epigenetic editing, regulation of gene expression, and molecular diagnostic methods. This article aims to present a review of the applications of the CRISPR-Cas molecular tool, particularly in the biomedical field, possible treatments and diagnoses, and the advances in clinical research, using the most relevant CRISPR-Cas gene therapy to date. (AU)

An epidermal growth factor motif of developmental endothelial locus 1 protein inhibits efficient angiogenesis in explanted squamous cell carcinoma in vivo

ABSTRACT Background: Cancer gene therapy using a nonviral vector is expected to be repeatable, safe, and inexpensive, and to have long-term effectiveness. Gene therapy using the E3 and C1 (E3C1) domain of developmental endothelial locus-1 (Del1) has been shown to improve prognosis in a mouse transplanted tumor model. Objective: In this study, we examined how this treatment affects angiogenesis in mouse transplanted tumors. Materials and methods: Mouse transplanted tumors (SCCKN human squamous carcinoma cell line) were injected locally with a nonviral plasmid vector encoding E3C1 weekly. Histochemical analysis of the transplanted tumors was then performed to assess the effects of E3C1 on prognosis. Results: All mice in the control group had died or reached an endpoint within 39 days. In contrast, one of ten mice in the E3C1 group had died by day 39, and eight of ten had died or reached an endpoint by day 120 (p < 0.01). Enhanced apoptosis in tumor stroma was seen on histochemical analyses, as was inhibited tumor angiogenesis in E3C1-treated mice. In addition, western blot analysis showed decreases in active Notch and HEY1 proteins. Conclusion: These findings indicate that cancer gene therapy using a nonviral vector encoding E3C1 significantly improved life-span by inhibiting tumor angiogenesis. (REV INVEST CLIN. 2021;73(1):39-51)

The use of miR122 and its target sequence in adeno-associated virus-mediated trichosanthin gene therapy / 中西医结合学报

OBJECTIVE@#Plant-derived cytotoxic transgene expression, such as trichosanthin (tcs), regulated by recombinant adeno-associated virus (rAAV) vector is a promising cancer gene therapy. However, the cytotoxic transgene can hamper the vector production in the rAAV producer cell line, human embryonic kidney (HEK293) cells. Here, we explored microRNA-122 (miR122) and its target sequence to limit the expression of the cytotoxic gene in the rAAV producer cells.@*METHODS@#A miR122 target (122T) sequence was incorporated into the 3' untranslated region of the tcs cDNA sequence. The firefly luciferase (fluc) transgene was used as an appropriate control. Cell line HEK293-mir122 was generated by the lentiviral vector-mediated genome integration of the mir122 gene in parental HEK293 cells. The effects of miR122 overexpression on cell growth, transgene expression, and rAAV production were determined.@*RESULTS@#The presence of 122T sequence significantly reduced transgene expression in the miR122-enriched Huh7 cell line (in vitro), fresh human hepatocytes (ex vivo), and mouse liver (in vivo). Also, the normal liver physiology was unaffected by delivery of 122T sequence by rAAV vectors. Compared with the parental cells, the miR122-overexpressing HEK293-mir122 cell line showed similar cell growth rate and expression of transgene without 122T, as well as the ability to produce liver-targeting rAAV vectors. Fascinatingly, the yield of rAAV vectors carrying the tcs-122T gene was increased by 77.7-fold in HEK293-mir122 cells. Moreover, the tcs-122T-containing rAAV vectors significantly reduced the proliferation of hepatocellular carcinoma cells without affecting the normal liver cells.@*CONCLUSION@#HEK293-mir122 cells along with the 122T sequence provide a potential tool to attenuate the cytotoxic transgene expression, such as tcs, during rAAV vector production.

Research Progress on Gene Therapy for β-thalassemia---Review / 中国实验血液学杂志

β-thalassemia is a monogenetic inherited hemolytic anemia, which results in a series of pathophysiological changes due to partial or complete inhibition of the synthesis of β-globin chain. The curative therapy for this disease is to reconstitute hematopoiesis, and transplantation with genetically modified autologous hematopoietic stem cells can avoid the major difficulties of traditional allogeneic hematopoietic stem cell transplantation，such as HLA matching and immune rejection. β-thalassemia gene therapy strategies mainly include gene integration and genome editing. The former relies on the development of lentiviral vectors and adds a fully functional HBB gene to the chromosome; the latter rapidly develops with the research of specific nuclease which can repair the HBB gene in situ. In this review, the latest progress of the two strategies in gene therapy of β-thalassemia is summarized.

CRISPR/Cas: a Nobel Prize award-winning precise genome editing technology for gene therapy and crop improvement / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Since it was first recognized in bacteria and archaea as a mechanism for innate viral immunity in the early 2010s, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) has rapidly been developed into a robust, multifunctional genome editing tool with many uses. Following the discovery of the initial CRISPR/Cas-based system, the technology has been advanced to facilitate a multitude of different functions. These include development as a base editor, prime editor, epigenetic editor, and CRISPR interference (CRISPRi) and CRISPR activator (CRISPRa) gene regulators. It can also be used for chromatin and RNA targeting and imaging. Its applications have proved revolutionary across numerous biological fields, especially in biomedical and agricultural improvement. As a diagnostic tool, CRISPR has been developed to aid the detection and screening of both human and plant diseases, and has even been applied during the current coronavirus disease 2019 (COVID-19) pandemic. CRISPR/Cas is also being trialed as a new form of gene therapy for treating various human diseases, including cancers, and has aided drug development. In terms of agricultural breeding, precise targeting of biological pathways via CRISPR/Cas has been key to regulating molecular biosynthesis and allowing modification of proteins, starch, oil, and other functional components for crop improvement. Adding to this, CRISPR/Cas has been shown capable of significantly enhancing both plant tolerance to environmental stresses and overall crop yield via the targeting of various agronomically important gene regulators. Looking to the future, increasing the efficiency and precision of CRISPR/Cas delivery systems and limiting off-target activity are two major challenges for wider application of the technology. This review provides an in-depth overview of current CRISPR development, including the advantages and disadvantages of the technology, recent applications, and future considerations.

Progress in Gene Therapy of Sickle Cell Disease Based on Hemoglobin F--Review / 中国实验血液学杂志

Sickle cell disease (SCD) is a single gene genetic disease, which seriously threatens the life span and quality of patients. On the basis of the pathogenesis of SCD and the alternative therapy based on fetal hemoglobin F (HbF), the research progress of transcription factors involved in the regulation of HbF gene expression, such as BCL11A, ZBTB7A, KLF-1, c-MYB and SOX6, as well as the application of CRISPR / Cas9, TALEN, zinc finger nuclease and other gene editing technologies in this field has been made, providing a solid theoretical basis for the exploration of new treatment schemes for β- like hemoglobin diseases, such as sickle cell disease and β- thalassemia.

Anti-micro rna-221 a promising genetic therapy of oral squamous cell carcinoma (scc-25)

Abstract Micro-RNA-221(miR-221) is one of oncogenic miRNAs that plays a vital role in the development and progression of oral cancers. The aim of this study is to introduce a new gene therapy for oral squamous cell carcinoma by blocking the expression of oncogenic miR-221 by its inhibitor. The present work was performed on squamous cell carcinoma cell line SCC-25 and anti-miR-221 was delivered to the cells using an ultrasound micro bubbles. Assessment of the effect of miR-221 inhibitor on SCC-25 cells was done using MTT assay, cell cycle analysis and apoptosis detection. In addition, reverse transcription-polymerase chain reaction was also used to detect the expression -miR-221 and its target genes. Using ANOVA, statistical analysis of the results showed significant inhibition of cell viability with and induction of cell apoptosis of SCC-25 cell line after transfection. Moreover, the expression of miR-221, Epidermal growth factor receptor (EGFR) and CDKNIB/p27 were downregulated without significant difference. Transfection of SCC-25 by inhibitor of miR-221 resulting in blockage of its expression leading to arresting of tumor growth. These results proved the effective role of micro-RNA inhibitors as novel therapeutic agent for oral cancers.

Resumo Micro-RNA-221 (miR-221) é um dos miRNAs oncogênicos que desempenham um papel vital no desenvolvimento e progressão de carcinomas orais. O objetivo deste estudo é apresentar uma nova terapia gênica para o carcinoma epidermóide oral por meio do bloqueio da expressão do miR-221 oncogênico por seu inibidor. O presente trabalho foi realizado na linhagem de células de carcinoma de células escamosas SCC-25 e o anti-miR-221 foi administrado às células usando micro-bolhas de ultrassom. A avaliação do efeito do inibidor miR-221 em células SCC-25 foi feita usando ensaio de MTT, análise do ciclo celular e detecção de apoptose. Além disso, a reação em cadeia da polimerase com transcrição reversa também foi usada para detectar a expressão -miR-221 e seus genes-alvo. Usando ANOVA, a análise estatística dos resultados mostrou inibição significativa da viabilidade celular e indução da apoptose celular da linhagem celular SCC-25 após a transfecção. Além disso, a expressão de miR-221, receptor do fator de crescimento epidérmico (EGFR) e CDKNIB/p27 foram regulados para baixo sem diferença significativa. A transfecção de SCC-25 por inibidor de miR-221 resultou no bloqueio de sua expressão, levando à interrupção do crescimento do tumor. Esses resultados comprovaram o papel eficaz dos inibidores de micro-RNA como novo agente terapêutico para carcinomas orais.