RESUMEN
Early diagnosis and prognosis of cancer progression through biomarker profiling are crucial in managing colon cancer patients. Our research aimed to investigate the expression of miR-101-3p, miR-106a-5p, and miR-326 in tumor and adjacent healthy tissues of colon cancer patients and determine their potential diagnostic utility. This study included 40 patients divided into four groups according to the TNM staging classification. MiRNA expression was analyzed using qRT-PCR. The results showed that miR-101-3p, miR-106a-5p, and miR-326 are overexpressed in adjacent healthy tissues but decrease in advanced cancer stages. MiR-106a-5p and miR-326 are strongly correlated with colon cancer severity. These findings suggest that miRNA profiling could be useful for early diagnosis and prognosis in colon cancer management.
RESUMEN
Strategies to improve hematopoietic stem and progenitor cell (HSPC) mobilization from the bone marrow can have a pivotal role in addressing iatrogenic bone-marrow insufficiency from chemo(radio)therapy and overcoming peripheral blood stem cell transplantation (PBSCT) limitations such as insufficient mobilization. Granulocyte-colony stimulating factor (G-CSF) represents the standard mobilization strategy for HSPC and has done so for more than three decades since its FDA approval. Its association with non-G-CSF agents is often employed for difficult HSPC mobilization. However, obtaining a synergistic effect between the two classes is limited by different timing and mechanisms of action. Based on our previous in vitro results, we tested the mobilization potential of human chorionic gonadotropin (HCG), alone and in combination with G-CSF in vivo in a murine study. Our results show an improved mobilization capability of the combination, which seems to act synergistically in stimulating hematopoiesis. With the current understanding of the dynamics of HSPCs and their origins in more primitive cells related to the germline, new strategies to employ the mobilization of hematopoietic progenitors using chorionic gonadotropins could soon become clinical practice.
Asunto(s)
Trasplante de Células Madre de Sangre Periférica , Humanos , Animales , Ratones , Factor Estimulante de Colonias de Granulocitos/farmacología , Modelos Animales de Enfermedad , Células Madre Hematopoyéticas/metabolismo , Gonadotropina Coriónica/farmacologíaRESUMEN
miRNAs are a class of noncoding RNAs with gene regulation properties, and they function as key factors in cell homeostasis. The interaction of miRNAs with their target mRNAs is largely considered to rely on sequence complementarity; however, some evidence indicates that mature miRNAs can adopt diverse conformations with implications for their function. Using the oncogenic miR-181 family as a study model, we suggest that a potential relationship between the primary sequence and secondary structure of miRNAs may have an impact on the number and spectrum of targeted cellular transcripts. We further emphasize that specific alterations in miR-181 primary sequences might impose certain constraints on target gene selection compared with the wild-type sequences, leading to the targeting of new transcripts with upregulated function in cancer.
Asunto(s)
MicroARNs , Neoplasias , Humanos , MicroARNs/genética , MicroARNs/química , ARN Mensajero/genética , Neoplasias/genética , Neoplasias/terapia , Regulación de la Expresión GénicaRESUMEN
Circular RNAs (circRNAs) have gained recent attraction due to their functional versatility and particular structure connected to human diseases. Current investigations are focused on the interplay between their ability to sponge smaller species of RNAs, such as microRNAs (miRNAs), thus influencing their regulatory activity on gene expression and protein templates. Therefore, their reported implication in various biological processes axis has resulted in an accumulating number of studies. While the testing and annotation methods of novel circular transcripts are still under development, there is still a plethora of transcript candidates suitable for investigation in human disease. The discordance in the literature regarding the approaches used in circRNAs quantification and validation methods, especially regarding qRT-PCR, the current golden standard procedure, leads to high result variability and undermines the replicability of the studies. Therefore, our study will offer several valuable insights into bioinformatic data for experimental design for circRNA investigation and in vitro aspects. Specifically, we will highlight key aspects such as circRNA database annotation divergent primer design and several processing steps, such as RNAse R treatment optimization and circRNA enrichment assessment. Additionally, we will provide insights into the exploration of circRNA-miRNA interactions, a prerequisite for further functional investigations. With this, we aim to contribute to the methodological consensus in a currently expanding field with possible implications for assessing therapeutic targets and biomarker discovery.
Asunto(s)
MicroARNs , ARN Circular , Humanos , ARN Circular/genética , MicroARNs/genética , MicroARNs/metabolismo , Reacción en Cadena de la Polimerasa , Biología Computacional/métodos , Redes Reguladoras de Genes , Perfilación de la Expresión Génica/métodosRESUMEN
Semaphorins are regulatory molecules that are linked to the modulation of several cancer processes, such as angiogenesis, cancer cell invasiveness and metastasis, tumor growth, as well as cancer cell survival. Semaphorin (SEMA) activity depends on the cancer histotypes and their particularities. In broad terms, the effects of SEMAs result from their interaction with specific receptors/co-receptors - Plexins, Neuropilins and Integrins - and the subsequent effects upon the downstream effectors (e.g. PI3K/AKT, MAPK/ERK). The present article serves as an integrative review work, discussing the broad implications of semaphorins in cancer, focusing on cell proliferation/survival, angiogenesis, invasion, metastasis, stemness, and chemo-resistance/response whilst highlighting their heterogeneity as a family. Herein, we emphasized that semaphorins are largely implicated in cancer progression, interacting with the tumor microenvironment components. Whilst some SEMAs (e.g. SEMA3A, SEMA3B) function widely as tumor suppressors, others (e.g. SEMA3C) act as pro-tumor semaphorins. The differences observed in terms of the biological structure of SEMAs and the particularities of each cancer histotypes require that each semaphorin be viewed as a unique entity, and its roles must be researched accordingly. A more in-depth and comprehensive view of the molecular mechanisms that promote and sustain the malignant behavior of cancer cells is of utmost importance.
Asunto(s)
Neoplasias , Semaforinas , Humanos , Fosfatidilinositol 3-Quinasas , Neoplasias/patología , Neuropilinas/química , Semaforina-3A , Microambiente TumoralRESUMEN
The increasing burden on human malignant diseases became a major concern for healthcare practitioners, that must deal with tumor relapse and the inability to efficiently treat metastasis, in addition to side effects. Throughout the decades, many therapeutic strategies have been employed to improve the clinical outcomes of cancer patients and great efforts have been made to develop more efficient and targeted medicines. The malignant cell is characterized by genetic and epigenetic modifications, therefore targeting those specific drivers of carcinogenesis is highly desirable. Among the genome editing technologies, CRISPR/Cas9 stood as a promising candidate for cancer treatment alternatives, due to its low complexity design. First described as a defense mechanism of bacteria against invading foreign DNA, later it was shown that CRISPR components can be engineered to target specific DNA sequences in a test tube, a discovery that was awarded later with the Nobel Prize in chemistry for its rapid expansion as a reliable genome editing tool in many fields of research, including medicine. The present paper aims of describing CRISPR/Cas9 potential targets for malignant disorders, and the approaches used for achieving this goal. Aside from preclinical studies, we also present the clinical trials that use CRISPR-based technology for therapeutic purposes of cancer. Finally, a summary of the presented studies adds a more focused view of the therapeutic value CRISPR/Cas9 holds and the associated shortcomings.
Asunto(s)
Sistemas CRISPR-Cas , Edición Génica , Sistemas CRISPR-Cas/genética , ADN , Epigénesis Genética , Humanos , Recurrencia Local de Neoplasia/genéticaRESUMEN
A variety of medical procedures are classified as aerosol generating. However there is no consensus on whether some procedures such as nasopharyngeal swabbing can generate aerosols. During specimen collection, the contact of the nasopharyngeal swab with the respiratory mucosa often triggers defense reflexes such as sneezing and coughing, which generate airborne particles. The accumulation and persistence of a viral load from infectious aerosols for hours after their generation can represent a threat for increased spread of infection. Prospective observational cohort study in individuals tested for RT-PCR SARS-CoV-2 from July to October 2020. Participants were evaluated for the prevalence of aerosol generating events (AGEs) triggered by the nasopharyngeal swabbing. We used descriptive statistics to analyze the data set and the chi-square test for AGE comparison between sexes. Among 1239 individuals, we reported 264 in which AGEs were triggered by the specimen collection. 97 individuals tested positive for SARS-CoV-2, of which 20 presented AGEs. There were no significant differences in the occurrence of AGEs by age, but significant differences have been identified between sex and the occurrence of AGEs both in the SARS-CoV-2 negative and SARS-CoV-2 positive individuals. The prevalence of coughing or sneezing triggered by the nasopharyngeal swabbing was high among tested individuals. Testing facilities should ensure adequate availability of personal protective equipment (PPE) for the testing personnel, ensure appropriate ventilation of the rooms, and develop additional strategies to limit the risk of contamination of other participants to the testing session from potentially infectious and persistent aerosols.
Asunto(s)
COVID-19 , Pandemias , Aerosoles , COVID-19/diagnóstico , COVID-19/epidemiología , Tos/etiología , Humanos , Nasofaringe , Estudios Prospectivos , SARS-CoV-2 , EstornudoRESUMEN
Oral cancer is a common human malignancy that still maintains an elevated mortality rate despite scientific progress. Tumorigenesis is driven by altered gene expression patterns of proto-oncogenes and tumor-suppressor genes. MicroRNAs, a class of short non-coding RNAs involved in gene regulation, seem to play important roles in oral cancer development, progression, and tumor microenvironment modulation. As properties of microRNAs render them stable in diverse liquid biopsies, together with their differential expression signature in cancer cells, these features place microRNAs at the top of promising biomarkers for diagnostic and prognostic values. In this review, we highlight eight expression levels and functions of the most relevant microRNAs involved in oral cancer development, progression, and microenvironment sustainability. Furthermore, we emphasize the potential of using these small RNA species as non-invasive biomarkers for the early detection of oral cancerous lesions. Conclusively, we highlight the perspectives and limitations of microRNAs as novel diagnostic tools, as well as therapeutic models.
Asunto(s)
MicroARNs/genética , Neoplasias de la Boca/genética , Neoplasias de la Boca/patología , Biomarcadores de Tumor/genética , Carcinogénesis/genética , Expresión Génica/genética , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Biopsia Líquida , MicroARNs/metabolismo , Neoplasias de la Boca/metabolismo , Pronóstico , Transcriptoma/genética , Microambiente TumoralRESUMEN
Nongonadal tissues express luteinizing hormone-chorionic gonadotropin receptors (LHCG-R) which are essential for their growth during fetal development. Adult mesenchymal stem/stromal cells (MSCs) have been shown to express functional LHCG-R outside pregnancy conditions, making them susceptible to hCG stimulation. In the present study we tested the effect of hCG treatment on bone marrow (BM) derived adherent stem cells in vitro, isolated from a parous women, mother of male sons, in order to evaluate its effect on maternal MSCs and in the same time on fetal microchimeric stem cells (FMSCs), to better understand the outcomes of this safe and affordable treatment on cell proliferation and expression of pluripotency genes. Our study highlights the beneficial effects of hCG exposure on gene regulation in bone marrow adherent stem cells through the upregulation of pluripotency genes and selection of more primitive mesenchymal stem cells with a better differentiation potential. Validation of these effects on MSCs and FMSCs long after parturition in vivo represents a close perspective as it could set the premises of a new mobilization strategy for the stem cell transplantation procedures in the clinical setting.
Asunto(s)
Células de la Médula Ósea/citología , Quimerismo/efectos de los fármacos , Gonadotropina Coriónica/farmacología , Células Madre Fetales/citología , Células Madre Fetales/inmunología , Tolerancia Inmunológica/efectos de los fármacos , Regeneración/efectos de los fármacos , Adipocitos/citología , Adipocitos/efectos de los fármacos , Células de la Médula Ósea/efectos de los fármacos , Adhesión Celular/efectos de los fármacos , Técnicas de Cultivo de Célula , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/genética , Proliferación Celular/efectos de los fármacos , Separación Celular , Condrocitos/citología , Condrocitos/efectos de los fármacos , Femenino , Células Madre Fetales/efectos de los fármacos , Células Madre Fetales/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Osteogénesis/efectos de los fármacos , Osteogénesis/genéticaRESUMEN
BACKGROUND: Bladder cancer (BC) is a common urothelial malignancy, characterized by a high recurrence rate. The biology of bladder cancer is complex and needs to be deciphered. The latest evidence reveals the critical role of the non-coding RNAs, particularly microRNAs (miRNAs), as vital regulatory elements in cancer. METHOD: We performed a miRNAs microarray using paired tissues (tumor and adjacent normal bladder tissue), followed by the validation with qRT-PCR of five selected transcripts. Additional next-generation sequencing investigation established the interconnection among the altered miRNAs and mutated genes. Based on the overlapping between TCGA data and data obtained in the study, we focused on the systematic identification of altered miRNAs and genes mutated involved in bladder cancer tumorigenesis and progression. RESULTS: By overlapping the miRNAs expression data, the two patient cohorts, we identified 18 miRNAs downregulated and, 187 miRNAs upregulated. qRT-PCR validation was completed using a selected panel of two downregulated (miR-139-5p and miR-143-5p) and three up-regulated miRNAs (miR-141b, miR-200 s or miR-205). Altered miRNAs patterns are interrelated to bladder tumorigenesis, allowing them to be used for the development of novel diagnostic and prognostic biomarkers. Three EMT-related upregulated miRNAs have an essential role in the molecular mechanisms, specifically key processes underlying tumorigenesis, invasion and metastasis. Using the Ampliseq Cancer Panel kit and Ion Torrent PGM Next-Generation Sequencing an increased mutation rate for TP53, FGFR3, KDR, PIK3CA and ATM were observed, but the mutational status for only TP53 was correlated to the survival rate. The miRNAs pattern, along with the gene mutation pattern attained, can assist for better patient diagnosis. CONCLUSION: This study thereby incorporates miRNAs as critical players in bladder cancer prognosis, where their altered gene expression profiles have a critical biological function in relationship with tumor molecular phenotype. The miRNA-mRNA regulatory networks identified in BC are ripe for exploitation as biomarkers or targeted therapeutic strategies.
Asunto(s)
Perfilación de la Expresión Génica/métodos , Redes Reguladoras de Genes , MicroARNs/genética , Neoplasias de la Vejiga Urinaria/genética , Progresión de la Enfermedad , Transición Epitelial-Mesenquimal , Femenino , Regulación Neoplásica de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos , Masculino , PronósticoRESUMEN
[This corrects the article DOI: 10.18632/oncotarget.24637.].
RESUMEN
Cancer, and particularly colon cancer, is associated with an increasing number of cases resistant to chemotherapy. One approach to overcome this, and to improve the prognosis and outcome of patients, is the use of adjuvant therapy alongside the standard chemotherapy regiment. In the present study, the effect of deuterium-depleted water (DDW) as a potential modulator of adjuvant therapy on DLD-1 colorectal cancer models was assessed. A number of functionality assays were performed, including MTT, apoptosis and autophagy, and mitochondrial activity and senescence assays, in addition to assessing the capacity to modify the pattern of released miRNA via microarray technology. No significant effect on cell viability was identified, but an increase in mitochondrial activity and a weak pro-apoptotic effect were observed in the treated DLD-1 cells cultured in DDW-prepared medium compared with those grown in standard conditions (SC). Furthermore, the findings revealed the capacity of DDW medium to promote senescence to a higher degree compared with SC. The exosome-released miRNA pattern was significantly modified for the cells maintained in DDW compared with those maintained in SC. These findings suggest that DDW may serve as an adjuvant treatment; however, a better understanding of the underlying molecular mechanism of action will be useful for developing novel and efficient therapeutic strategies, in which the transcriptomic pattern serves an important role.
RESUMEN
Chimeric antigen receptor-modified T cells (CAR-T cells) and donor lymphocyte infusion (DLI) are important protocols in lymphocyte engineering. CAR-T cells have emerged as a new modality for cancer immunotherapy due to their potential efficacy against hematological malignancies. These genetically modified receptors contain an antigen-binding moiety, a hinge region, a transmembrane domain, and an intracellular costimulatory domain resulting in lymphocyte T cell activation subsequent to antigen binding. In present-day medicine, four generations of CAR-T cells are described depending on the intracellular signaling domain number of T cell receptors. DLI represents a form of adoptive therapy used after hematopoietic stem cell transplant for its anti-tumor and anti-infectious properties. This article covers the current status of CAR-T cells and DLI research in the intensive care unit (ICU) patient, including the efficacy, toxicity, side effects and treatment.
RESUMEN
Chimeric antigen receptor (CAR) T-cell technology has seen a rapid development over the last decade mostly due to the potential that these cells may have in treating malignant diseases. It is a generally accepted principle that very few therapeutic compounds deliver a clinical response without treatment-related toxicity, and studies have shown that CAR T-cells are not an exception to this rule. While large multinational drug companies are currently investigating the potential role of CAR T-cells in hematological oncology, the potential of such cellular therapies are being recognized worldwide as they are expected to expand in the patient to support the establishment of the immune memory, provide a continuous surveillance to prevent and/or treat a relapse, and keep the targeted malignant cell subpopulation in check. In this article, we present the possible advantages of using CAR T-cells in treating acute lymphoblastic leukemia, presenting the technology and the current knowledge in their preclinical and early clinical trial use. Thus, this article first presents the main present-day knowledge on the standard of care for acute lymphoblastic leukemia. Afterward, current knowledge is presented about the use of CAR T-cells in cancer immunotherapy, describing their design, the molecular constructs, and the preclinical data on murine models to properly explain the background for their clinical use. Last, but certainly not least, this article presents the use of CAR T-cells for the immunotherapy of B-cell acute lymphoblastic leukemia, describing both their potential clinical advantages and the possible side effects.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Inmunoterapia Adoptiva/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Receptores Quiméricos de Antígenos/inmunología , Linfocitos T/trasplante , Animales , Sistemas CRISPR-Cas/genética , Ingeniería Celular/métodos , Modelos Animales de Enfermedad , Ingeniería Genética/métodos , Enfermedad Injerto contra Huésped/inmunología , Enfermedad Injerto contra Huésped/prevención & control , Humanos , Inmunoterapia Adoptiva/efectos adversos , Ratones , Leucemia-Linfoma Linfoblástico de Células Precursoras/inmunología , Receptores Quiméricos de Antígenos/genética , Trasplante de Células Madre , Linfocitos T/inmunología , Resultado del TratamientoRESUMEN
With an increasing prevalence in the human population, cancer has become one of the most investigated fields of medicine. Among the potential targets for cancer therapy is the tumor suppressor gene TP53, which is found in a mutated state in approximately 50% of human cancers and is often associated with poor prognosis. We propose a novel, highly tumor-specific delivery system for TP53, based on the CRISPR/Cas9 genome editing technology. This system will restore the normal p53 phenotype in tumor cells by replacing the mutant TP53 gene with a functional copy, leading to sustained expression of p53 protein and tumor regression.
Asunto(s)
Sistemas CRISPR-Cas , Edición Génica/métodos , Terapia Genética/métodos , Neoplasias/terapia , Proteína p53 Supresora de Tumor/genética , Animales , Proteína 9 Asociada a CRISPR , Modelos Animales de Enfermedad , Vectores Genéticos , Humanos , Ratones , Mutación , Neoplasias/genética , PronósticoRESUMEN
With the expansion of the microbiology field of research, a new genome editing tool arises from the biology of bacteria that holds the promise of achieving precise modifications in the genome with a simplicity and versatility that surpasses previous genome editing methods. This new technique, commonly named CRISPR/Cas9, led to a rapid expansion of the biomedical field; more specifically, cancer characterization and modeling have benefitted greatly from the genome editing capabilities of CRISPR/Cas9. In this paper, we briefly summarize recent improvements in CRISPR/Cas9 design meant to overcome the limitations that have arisen from the nuclease activity of Cas9 and the influence of this technology in cancer research. In addition, we present challenges that might impede the clinical applicability of CRISPR/Cas9 for cancer therapy and highlight future directions for designing CRISPR/Cas9 delivery systems that might prove useful for cancer therapeutics.
RESUMEN
Triple-negative breast cancer (TNBC) is a heterogeneous group of tumours characterised by lack of expression of oestrogen-, progesterone- and human epidermal growth factor receptors. TNBC, which represents approximately 15% of all mammary tumours, has a poor prognosis because of an aggressive behaviour and the lack of specific treatment. Accordingly, TNBC has become a major focus of research into breast cancer and is now classified into several molecular subtypes, each with a different prognosis. Pathological angiogenesis occurs at a late stage in the proliferation of TNBC and is associated with invasion and metastasis; there is an association with metabolic syndrome. Semaphorins are a versatile family of proteins with multiple roles in angiogenesis, tumour growth and metastasis and may represent a clinically useful focus for therapeutic targeting in this type of breast cancer. Another important field of investigation into the control of pathological angiogenesis is related to the expression of noncoding RNA (ncRNA) - these molecules can be considered as a therapeutic target or as a biomarker. Several molecular agents for intervening in the activity of different signalling pathways are being explored in TNBC, but none has so far proved effective in clinical trials and the disease continues to pose a defining challenge for clinical management as well as innovative cancer research.
Asunto(s)
Neovascularización Patológica , Neoplasias de la Mama Triple Negativas/etiología , Neoplasias de la Mama Triple Negativas/metabolismo , Inhibidores de la Angiogénesis/farmacología , Inhibidores de la Angiogénesis/uso terapéutico , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Estudios Clínicos como Asunto , Evaluación Preclínica de Medicamentos , Femenino , Perfilación de la Expresión Génica/métodos , Regulación Neoplásica de la Expresión Génica , Humanos , Síndrome Metabólico/metabolismo , Síndrome Metabólico/patología , Neovascularización Patológica/tratamiento farmacológico , Neovascularización Patológica/genética , Neovascularización Patológica/metabolismo , Proteoma , Proteómica/métodos , ARN no Traducido/genética , Semaforinas/genética , Semaforinas/metabolismo , Transducción de Señal , Neoplasias de la Mama Triple Negativas/diagnóstico , Neoplasias de la Mama Triple Negativas/terapiaRESUMEN
The function of the epithelial Na+ channel from the apical membrane of many Na+ transporting epithelia is modulated by various chemical compounds from the extracellular space, such as heavy metals, protons or chloride ions. We have studied the effect of extracellular Cd2+ on the function of the epithelial Na+ channel (ENaC) in heterologously expressed Xenopus laevis oocytes and Na+-transporting epithelia. We assayed channel function as the amiloride-sensitive sodium current (I(Na)). Cd2+ rapidly and voltage-independently inhibited INa in oocytes expressing αßγ Xenopus ENaC (xENaC). The extracellular Cd2+ inhibited Na+ transport and showed no influence on ENaC trafficking, as revealed by concomitant measurements of the transepithelial current, conductance and capacitance in Na+-transporting epithelia. Instead, amiloride inhibition was noticeably diminished in the presence of Cd2+ on the apical membrane. Using molecular modeling approaches, we describe the amiloride binding sites in rat and xENaC structures, and we present four putative binding sites for Cd2+. These results indicate that ENaC functions as a sensor for external Cd2+.
Asunto(s)
Cadmio/administración & dosificación , Canales Epiteliales de Sodio/química , Canales Epiteliales de Sodio/fisiología , Oocitos/fisiología , Sodio/metabolismo , Animales , Sitios de Unión , Células Cultivadas , Relación Dosis-Respuesta a Droga , Canales Epiteliales de Sodio/efectos de los fármacos , Activación del Canal Iónico/efectos de los fármacos , Activación del Canal Iónico/fisiología , Modelos Químicos , Simulación del Acoplamiento Molecular , Oocitos/efectos de los fármacos , Unión Proteica , Xenopus laevisRESUMEN
The emergence of genetic engineering at the beginning of the 1970's opened the era of biomedical technologies, which aims to improve human health using genetic manipulation techniques in a clinical context. Gene therapy represents an innovating and appealing strategy for treatment of human diseases, which utilizes vehicles or vectors for delivering therapeutic genes into the patients' body. However, a few past unsuccessful events that negatively marked the beginning of gene therapy resulted in the need for further studies regarding the design and biology of gene therapy vectors, so that this innovating treatment approach can successfully move from bench to bedside. In this paper, we review the major gene delivery vectors and recent improvements made in their design meant to overcome the issues that commonly arise with the use of gene therapy vectors. At the end of the manuscript, we summarized the main advantages and disadvantages of common gene therapy vectors and we discuss possible future directions for potential therapeutic vectors.