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Skin cancer is one of the most widespread cancers, with a significant global health effect. UV-induced DNA damage in skin cells triggers them to grow and proliferate out of control, resulting in cancer development. Two common types of skin cancer include melanoma skin cancer (MSC) and non-melanoma skin cancer (NMSC). Melanoma is the most lethal form of skin cancer, and NMSC includes basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and other forms. The incidence of skin cancer is increasing in part owing to a demographic shift toward an aging population, which is more prone to NMSC, imposing a considerable financial strain on public health services. The introduction of immunostimulatory approaches for cancer cell eradication has led to significant improvements in skin cancer treatment. Over the last three decades, monoclonal antibodies have been used as powerful human therapeutics besides scientific tools, and along with the development of monoclonal antibody production and design procedures from chimeric to humanized and then fully human monoclonal antibodies more than 6 monoclonal antibodies have been approved by the food and drug administration (FDA) and have been successful in skin cancer treatment. In this review, we will discuss the epidemiology, immunology, and therapeutic approaches of different types of skin cancer.
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The successful outcomes of chimeric antigen receptor (CAR) T-cell therapy in treating hematologic cancers have increased the previously unprecedented excitement to use this innovative approach in treating various forms of human cancers. Although researchers have put a lot of work into maximizing the effectiveness of these cells in the context of solid tumors, few studies have discussed challenges and potential strategies to overcome them. Restricted trafficking and infiltration into the tumor site, hypoxic and immunosuppressive tumor microenvironment (TME), antigen escape and heterogeneity, CAR T-cell exhaustion, and severe life-threatening toxicities are a few of the major obstacles facing CAR T-cells. CAR designs will need to go beyond the traditional architectures in order to get over these limitations and broaden their applicability to a larger range of malignancies. To enhance the safety, effectiveness, and applicability of this treatment modality, researchers are addressing the present challenges with a wide variety of engineering strategies as well as integrating several therapeutic tactics. In this study, we reviewed the antigens that CAR T-cells have been clinically trained to recognize, as well as counterstrategies to overcome the limitations of CAR T-cell therapy, such as recent advances in CAR T-cell engineering and the use of several therapies in combination to optimize their clinical efficacy in solid tumors.
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Neoplasias , Receptores Quiméricos de Antígenos , Humanos , Inmunoterapia Adoptiva , Antígenos de Neoplasias , Linfocitos T , Microambiente TumoralRESUMEN
INTRODUCTION: Graft-versus-host disease (GvHD) is a life-threatening syndrome commonly associated with hematopoietic stem cell transplantation (HSCT). Preventing the incidence of GVHD after HSCT along with minimizing long-term immunosuppression is currently under investigation with regulatory T cells (Tregs). As Tregs are a low-frequency population and the yield of all memory Tregs is not sufficient for clinical application, an initial Treg expansion is essential. METHODS: Thirty milliliters of peripheral blood from the ß-thalassemia major (beta-TM) patients and healthy controls were obtained and Tregs were isolated using MACS. Isolated cells were cultured in the presence of rapamycin and rIL-2 followed by activated with anti-CD3/CD28-coated beads. To evaluate Treg plasticity, expanded Tregs were cultured in a medium containing IL1ß, IL6, TGFß, and IL2, with or without 500 nM rapamycin for 72 h. To assess the functional properties of Tregs, CFSE dilution assays were performed to evaluate the ability of in vivo expanded Tregs from beta-TM patients. Statistical analysis was performed using paired t-test and independent t-test, with the aid of SPSS version 12.0. p-value ≤0.05 was considered significant. RESULTS: The percentage of Tregs isolated from the control group was significantly higher than the Tregs isolated from patients (p-value = 0.01), which is probably due to the iron overload in beta-TM patients as a result of continuous blood transfusion. Also, the percentage of Tregs after 5 days of expansion had a significant increase in both groups compared to before expansion (p-value = 0.03). Our results also showed that the expansion of Tregs after 72 h in the presence of inflammatory cytokines and in the absence of rapamycin led to the increase in the intracellular expression of IL-17 (p-value = 0.01), while intracellular expression of IL-17 remained low following the addition of 100 nM rapamycin to the culture medium (pvalue = 0.073). The results of the functional evaluation of expanded Tregs showed relatively differences in both patient and control groups. Thus, expanded Tregs inhibited the proliferation of responder T cells in a dose-dependent manner in the control group (p-value = 0.028), while in the patient group this inhibitory effect was not significant (p-value = 0.055). CONCLUSION: Tregs isolated from beta-TM patients have poorer inhibitory performance than Tregs isolated from healthy individuals. Also, we concluded that rapamycin stabilizes the Treg population by inhibiting the production of IL-17, all necessitating the administration of appropriate immunosuppressive drugs in patients receiving Treg therapy.
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Enfermedad Injerto contra Huésped , Talasemia beta , Humanos , Linfocitos T Reguladores/metabolismo , Citocinas/metabolismo , Interleucina-17/metabolismo , Talasemia beta/terapia , Talasemia beta/metabolismo , Sirolimus/farmacología , Sirolimus/metabolismo , Enfermedad Injerto contra Huésped/metabolismo , Enfermedad Injerto contra Huésped/prevención & controlRESUMEN
BACKGROUND: Aquaporins are channel proteins, form pores in the membrane of biological cells to facilitate the transcellular and transepithelial water movement. The role of Aquaporins in carcinogenesis has become an area of interest. In this study, we aimed to investigate the effects of adipose-derived mesenchymal stem cells secreted exosomes on the expression of aquaporin 5 and EGFR genes in the HCT-116 tumor cell line. METHODS AND RESULTS: Surface antigenic profile of Ad-MSCs was evaluated using specific markers. Exosomes were purified from the Ad-MSc supernatant while the quality and the shape of isolated exosomes were assessed by western blot and transmission electron microscopy (TEM) respectively. HCT-116 cells were co-cultured with MSC-conditioned medium (MSC-CM) and/or with 100 µg/ml of MSC-derived exosomes for 48 h and. Real-time PCR was carried out to determine the expression of aquaporin5 and EGFR in HCT-116. Relative expression levels were calculated using the 2-ΔΔct method. Our result showed that AQP5 and EGFR mRNA levels were significantly reduced in CM and/or exosomes treated HCT116 compare to the control group (P-value < 0.05). CONCLUSION: The current study showed that MSC derived exosomes could inhibit expression of two important molecules involved in tumor progression. Hence it seems MSCs-derived exosomes may hold a hopeful future as drug delivery vehicles which need the furtherer investigation.
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Neoplasias Colorrectales , Exosomas , Células Madre Mesenquimatosas , Acuaporina 5/genética , Acuaporina 5/metabolismo , Línea Celular Tumoral , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Medios de Cultivo Condicionados/farmacología , Receptores ErbB/metabolismo , Exosomas/metabolismo , Humanos , Células Madre Mesenquimatosas/metabolismo , ARN Mensajero/metabolismoRESUMEN
The human colon harbors a diverse array of microorganisms that play fundamental roles in colorectal cancer (CRC). Increasing evidence indicates that dysbiosis of the intestinal microbiome has been associated with the development of CRC. Interaction between host genetics, intestinal microbiota, and lifestyle is well-indicated in the influence, prevention, and treatment of CRC. Various microbiome compositions have reported anticancer and/or anti-inflammatory properties. The presence of our microbiota is integral to our development, but a change in its composition can often lead to adverse effects, increasing the propensity for serious diseases like cancers. Recently, molecular detection and metabolomic techniques have increased our knowledge of the role of microbiota in promoting tumorigenesis. Dietary interventions may be appropriate to regulate the growth of beneficial microbiota in the gut. Metagenomic approaches along with immunology and metabolomics will obvious a new path for the treatment of CRC. In this study, we summarized recent advances in understanding the mechanisms involved in microbiota-related colorectal carcinoma, based on evidence from immunotherapy studies.
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Neoplasias Colorrectales , Microbioma Gastrointestinal , Microbiota , Humanos , Neoplasias Colorrectales/terapia , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/patología , Disbiosis/terapia , InmunoterapiaRESUMEN
Cytokines play pivotal functions in coronavirus disease 2019 (COVID-19) pathogenesis. However, little is known about the rationale and importance of genetic variations associated with immune system responses, so-called "immunogenetic profiling." We studied whether polymorphisms of IL6, IL6R, TNFA, and IL1RN affect the disorder severity and outcome in patients infected with COVID19. We recruited 317 hospitalized patients with laboratory-confirmed COVID-19 from Bu-Ali hospital and 317 high-risk participants who had high exposure to COVID-19 patients but with a negative real-time-polymerase chain reaction (PCR) test. Multiple regression analyses were applied. We indicated that participants carrying the A allele in TNFA-rs361525, G>A (p < .004), the C allele in IL1RN-rs419598 T>C (p < .004), the A allele in IL6R-rs2228145, A>C (p = .047) are more susceptible to develop COVID-19. In contrast, those who carry the G allele of IL6-rs2069827, G>T (p = .01), are more protected from COVID-19. Also, we compared the various genotypes regarding the disorder severity and poor prognosis; we found that the AA genotype in TNFA is related to more aggressive illness and bad prognostic in contrast to the other inflammatory cytokines' genotypes. In addition, a high level of inflammatory indications, such as neutrophil-to-lymphocyte ratio and systemic immune-inflammation index, was observed in deceased patients compared with the survived subjects (p < .0001). We advised considering inflammatory cytokines polymorphisms as the main item to realize the therapeutic response against the acute respiratory distress syndrome induced by the SARS-CoV-2 virus.
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COVID-19 , Polimorfismo de Nucleótido Simple , COVID-19/genética , Citocinas/genética , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Proteína Antagonista del Receptor de Interleucina 1/genética , Interleucina-6/genética , Irán/epidemiología , Receptores de Interleucina-6/genética , SARS-CoV-2 , Factor de Necrosis Tumoral alfa/genéticaRESUMEN
The issue of treating Multiple Sclerosis (MS) begins with disease-modifying treatments (DMTs) which may cause lymphopenia, dyspnea, and many other adverse effects. Consequently, further identification and evaluation of alternative treatments are crucial to monitoring their long-term outcomes and hopefully, moving toward personalized approaches that can be translated into clinical treatments. In this article, we focused on the novel therapeutic modalities that alter the interaction between the cellular constituents contributing to MS onset and progression. Furthermore, the studies that have been performed to evaluate and optimize drugs' efficacy, and particularly, to show their limitations and strengths are also presented. The preclinical trials of novel approaches for multiple sclerosis treatment provide promising prospects to cure the disease with pinpoint precision. Considering the fact that not a single treatment could be effective enough to cover all aspects of MS treatment, additional researches and therapies need to be developed in the future. Since the pathophysiology of MS resembles a jigsaw puzzle, researchers need to put a host of pieces together to create a promising window towards MS treatment. Thus, a combination therapy encompassing all these modules is highly likely to succeed in dealing with the disease. The use of different therapeutic approaches to re-induce self-tolerance in autoreactive cells contributing to MS pathogenesis is presented. A Combination therapy using these tools may help to deal with the clinical disabilities and symptoms of the disease in the future.
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Esclerosis Múltiple , Ácidos Nucleicos , Humanos , Esclerosis Múltiple/tratamiento farmacológico , Ácidos Nucleicos/uso terapéuticoRESUMEN
Recent emergence of SARS-CoV-2 and associated COVID-19 pandemic have posed a great challenge for the scientific community. In this study, we performed bioinformatic analyses on SARS-CoV-2 protein sequences, trying to unravel potential molecular similarities between this newly emerged pathogen with non-coronavirus ssRNA viruses. Comparing the proteins of SARS-CoV-2 with non-coronavirus positive and negative strand ssRNA viruses revealed multiple sequence similarities between SARS-CoV-2 and non-coronaviruses, including similarities between RNA-dependent RNA-polymerases and helicases (two highly-conserved proteins). We also observed similarities between SARS-CoV-2 surface (i.e. spike) protein with paramyxovirus fusion proteins. This similarity was restricted to a segment of spike protein S2 subunit which is involved in cell fusion. We next analyzed spike proteins from SARS-CoV-2 "variants of concern" (VOCs) and "variants of interests" (VOIs) and found that some of these variants show considerably higher spike-fusion similarity with paramyxoviruses. The 'spike-fusion' similarity was also observed for some pathogenic coronaviruses other than SARS-CoV-2. Epitope analysis using experimentally verified data deposited in Immune Epitope Database (IEDB) revealed that several B cell epitopes as well as T cell and MHC binding epitopes map within the spike-fusion similarity region. These data indicate that there might be a degree of convergent evolution between SARS-CoV-2 and paramyxovirus surface proteins which could be of pathogenic and immunological importance.
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SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/genética , Proteínas Virales de Fusión/genética , Epítopos/genética , Humanos , Paramyxoviridae/genética , Filogenia , Estructura Terciaria de Proteína , Glicoproteína de la Espiga del Coronavirus/químicaRESUMEN
As co-stimulatory receptors, immune checkpoint molecules are found on the surface of various immune cells and transduce inhibitory signals following ligand binding. The most studied members in this regard include PD-1, TIM-3, and CTLA-4. The physiological part immune checkpoints possess is the prevention of dangerous immune attacks towards self-antigens throughout an immune response, which takes place through the negative regulation of the effector immune cells, through the induction of T-cell exhaustion, for instance. It has recently been suggested that each checkpoint reduces immunoactivation via distinct intracellular mechanisms of signaling. Regulators of immune checkpoints are supposed to participate actively in immune defense mechanisms against infections, preventing autoimmunity, transplantation, and tumor immune evasion. In pregnancy, as an active immunotolerance mechanism which is also natural, the maternal immune system encounters two simultaneous challenges; in addition to accepting the semi-allogeneic fetus, the maternal immune system should also prevent infections. In this regard, the part immune checkpoint molecules possess is particularly interesting. Herein, the current understanding of such part in reproductive immunology is described.
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Biomarcadores/metabolismo , Antígeno CTLA-4/metabolismo , Receptor 2 Celular del Virus de la Hepatitis A/metabolismo , Inhibidores de Puntos de Control Inmunológico/metabolismo , Infertilidad/inmunología , Receptor de Muerte Celular Programada 1/metabolismo , Animales , Autoinmunidad , Humanos , Tolerancia Inmunológica , Inmunidad , Inmunoterapia , Infertilidad/terapia , Ligandos , Neoplasias , Transducción de Señal/inmunología , Escape del TumorRESUMEN
Organ transplantation is a practical treatment for patients with end-stage organ failure. Despite the advances in short-term graft survival, long-term graft survival remains the main challenge considering the increased mortality and morbidity associated with chronic rejection and the toxicity of immunosuppressive drugs. Since a novel therapeutic strategy to induce allograft tolerance seems urgent, focusing on developing novel and safe approaches to prolong graft survival is one of the main goals of transplant investigators. Researchers in the field of organ transplantation are interested in suppressing or optimizing the immune responses by focusing on immune cells including mesenchymal stem cells (MSCs), polyclonal regulatory Tcells (Tregs), and antigen-specific Tregs engineered with chimeric antigen receptors (CAR Tregs). We review the mechanistic pathways, phenotypic and functional characteristics of these cells, and their promising application in organ transplantation.
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Rechazo de Injerto/prevención & control , Enfermedad Injerto contra Huésped/prevención & control , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Trasplante de Células Madre Mesenquimatosas , Trasplante de Órganos/efectos adversos , Linfocitos T Reguladores/trasplante , Aloinjertos/inmunología , Animales , Ensayos Clínicos como Asunto , Modelos Animales de Enfermedad , Rechazo de Injerto/inmunología , Enfermedad Injerto contra Huésped/inmunología , Humanos , Inmunosupresores/administración & dosificación , Inmunosupresores/efectos adversos , Inmunoterapia Adoptiva/métodos , Receptores Quiméricos de Antígenos/genética , Receptores Quiméricos de Antígenos/inmunología , Linfocitos T Reguladores/inmunología , Tolerancia al Trasplante/efectos de los fármacos , Tolerancia al Trasplante/inmunología , Trasplante Autólogo/métodos , Trasplante Homólogo/efectos adversos , Resultado del TratamientoRESUMEN
Coronavirus disease 2019 (COVID-19) infection which is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has led to a "public health emergency of international concern" (PHEIC). The infection is highly contagious, has a high mortality rate, and its pathophysiology remains poorly understood. Pulmonary inflammation with substantial lung damage together with generalized immune dysregulation are major components of COVID-19 pathogenesis. The former component, lung damage, seems to be at least in part a consequence of immune dysregulation. Indeed, studies have revealed that immune alteration is not merely an association, as it might occur in systemic infections, but, very likely, the core pathogenic element of COVID-19. In addition, precise management of immune response in COVID-19, i.e. enhancing anti-viral immunity while inhibiting systemic inflammation, may be key to successful treatment. Herein, we have reviewed current evidence related to different aspects of COVID-19 immunology, including innate and adaptive immune responses against the virus and mechanisms of virus-induced immune dysregulation. Considering that current antiviral therapies are chiefly experimental, strategies to do immunotherapy for the management of disease have also been reviewed. Understanding immunology of COVID-19 is important in developing effective therapies as well as diagnostic, and prophylactic strategies for this disease.
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COVID-19/inmunología , COVID-19/terapia , COVID-19/patología , Humanos , Inmunidad , Inmunoterapia/métodos , SARS-CoV-2/aislamiento & purificaciónRESUMEN
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can trigger a cytokine storm in the pulmonary tissue by releasing various types of mediators, leading to acute respiratory distress syndrome (ARDS). Increased neutrophil-to-lymphocyte ratio, as well as CD4+ T lymphopenia, is reported in cases with novel coronavirus disease (COVID-19), meanwhile, lymphopenia is a significant finding in the majority of COVID-19 cases with a severe phenotype. Moreover, excessive activation of monocyte/macrophage and cytokine storms are associated with the severity of the disease and the related complications in SARS-CoV-2 infection. Understanding the immune response dysregulation in COVID-19 is essential to develop more effective diagnostic, therapeutic, and prophylactic strategies in this pandemic.
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COVID-19/patología , Inmunidad , COVID-19/complicaciones , COVID-19/inmunología , COVID-19/virología , Proteínas del Sistema Complemento/metabolismo , Síndrome de Liberación de Citoquinas/etiología , Humanos , Monocitos/citología , Monocitos/inmunología , Monocitos/metabolismo , SARS-CoV-2/aislamiento & purificación , Índice de Severidad de la Enfermedad , Linfocitos T Citotóxicos/citología , Linfocitos T Citotóxicos/inmunología , Linfocitos T Citotóxicos/metabolismoRESUMEN
It is still unclear whether toll-like receptor (TLR) signaling and serum levels of inflammatory markers in metabolically unhealthy abdominally obese (MUAO) are due to their obesity and/or their metabolic state. We hypothesized that abdominal obesity is an important mediator of the association of metabolic state with TLR signaling and serum inflammatory markers. Therefore, in this case-control study, we compared the expression levels of TLR4 and Toll/interleukin-1 receptor domain containing adaptor protein-inducing interferon ß (TRIF) and serum concentrations of interferon ß and lipoprotein-binding protein (LBP) in metabolically healthy abdominally obese (MHAO) and MUAO individuals. Basal blood samples from 65 abdominally obese subjects with waist circumference (WC) of at least 95 cm were collected to determine serum metabolic parameters, IFNß, and LBP. Those with 3 or more metabolic alterations were defined as MUAO (nâ¯=â¯34), and those having 2 or less were classified as MHAO (nâ¯=â¯31). Furthermore, messenger RNA (mRNA) was isolated from peripheral blood mononuclear cells. TLR4 and TRIF gene expression assay was performed using quantitative real-time polymerase chain reaction. There were significant differences in serum fasting blood sugar (Pâ¯=â¯.017), triglyceride (Pâ¯<â¯.001), cholesterol (Pâ¯=â¯.002), and low-density lipoprotein cholesterol (Pâ¯=â¯.034) between the MUAO and MHAO groups, whereas no significant difference was observed in the expression ratio of TLR4 and TRIF mRNA and serum levels of IFNß and LBP. However, a significant correlation was noticed between mRNA expression levels of TLR4 and TRIF (râ¯=â¯0.50, Pâ¯<â¯.001) and serum IFNß and LBP (râ¯=â¯0.70, Pâ¯<â¯.001). It is concluded that the expression levels of TLR4 and TRIF as well as serum IFNß and LBP are more related to abdominal obesity than to metabolic health.
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Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Proteínas Portadoras/sangre , Inflamación/sangre , Interferón beta/sangre , Glicoproteínas de Membrana/sangre , Síndrome Metabólico/metabolismo , Obesidad Abdominal/metabolismo , Receptor Toll-Like 4/metabolismo , Proteínas de Fase Aguda , Adulto , Glucemia/metabolismo , Estudios de Casos y Controles , Femenino , Humanos , Leucocitos Mononucleares/metabolismo , Lípidos/sangre , Masculino , Síndrome Metabólico/complicaciones , Obesidad Abdominal/complicaciones , ARN Mensajero/sangre , Reacción en Cadena en Tiempo Real de la Polimerasa , Valores de Referencia , Transducción de Señal , Circunferencia de la CinturaRESUMEN
Purpose: Introducing the effect of RNAi in fungi to downregulate essential genes has made it a powerful tool to investigate gene function, with potential strategies for novel disease treatments. Thus, this study is an endeavor to delve into the silencing potentials of siRNA on cyp51A and MDR1 in voriconazole-resistant Aspergillus flavus as the target genes. Methods: In this study, we designed three cyp51A-specific siRNAs and three MDR1-specific siRNAs and after the co-transfection of siRNA into Aspergillus flavus, using lipofectamine, we investigated the effect of different siRNA concentrations (5, 15, 25, 50nM) on cyp51A and MDR1 expressions by qRT-PCR. Finally, the Minimum Inhibitory Concentrations (MICs) of voriconazole for isolates were determined by broth dilution method. Results: Cyp51A siRNA induced 9, 22, 33, 40-fold reductions in cyp51A mRNA expres-sion in a voriconazole-resistant strain following the treatment of the cells with concentrations of 5, 15, 25, 50nM siRNA, respectively. Identically, the same procedure was applied to MDR1, even though it induced 2, 3, 4, 10-fold reductions. The results demonstrated a MIC for voriconazole in the untreated group (4µg per ml), when compared to the group treated with cyp51A-specific siRNA and MDR1-specific siRNA, both at concentrations of 25 and 50nM, yielding 2µg per ml and 1µg per ml when 25 nM was applied and 2µg per ml and 0.5µg per ml when the concentration doubled to 50 nM. Conclusion: In this study, we suggested that siRNA-mediated specific inhibition of cyp51A and MDR1 genes play roles in voriconazole-resistant A.flavus strain and these could be apt target genes for inactivation. The current study promises a bright prospect for the treatment of invasive aspergillosis through the effective deployment of RNAi and gene therapy.
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BACKGROUND: The natural products derived from micro-organisms are potential candidates for the discovery of novel drugs. Streptomyces bacteria are prolific sources of secondary metabolites with a wide variety of biological activities. Streptomyces calvus (S. calvus) is one strain of this genus and may be an appropriate candidate for isolating new compounds. In this study, the immunomodulatory effects of S. calvus secondary metabolites on the expression of various cytokine genes by human peripheral blood mononuclear cells (PBMCs) were evaluated. METHODS: A bacterial sample was inoculated in Mueller Hinton Broth and secondary metabolites were extracted. PBMCs were isolated from venous blood and were treated with S. calvus secondary metabolites for 48 h. The cell proliferation was assessed by Methyl tetrazolium bromide (MTT) assay and quantitative real-time polymerase chain reaction (qRT-PCR) assays to survey mRNA expressions of selected pro-inflammatory and inhibitory cytokine genes. RESULTS: Secondary metabolites augmented interleukin-2 and interferon-γ gene expression in PBMCs at low doses and also reduced the levels of immunosuppressive cytokine interleukin-10. In addition, the proliferation of PBMCs substantially increased in response to metabolite treatment in a concentration-dependent manner (p < 0.001). CONCLUSION: This in vitro study revealed that the secondary metabolites from S. calvus can successfully stimulate human PBMCs. Therefore, these metabolites have the potential to serve as robust immunomodulators.
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Proliferación Celular/efectos de los fármacos , Factores Inmunológicos/biosíntesis , Leucocitos Mononucleares/efectos de los fármacos , Streptomyces/metabolismo , Humanos , Técnicas In Vitro , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
The effectiveness of chemotherapy is one of the main challenges in cancer treatment and resistance to classic drugs and traditional treatment processes is an obstacle to this goal. Drug resistance that may be inherent or adventitious can cause poor treatment outcome and tumor relapse. In most cases, resistance to a drug can lead to resistance to many other drugs structure and function of which is not necessarily similar to the first drug. This phenomenon is the main mechanism behind failure of many of metastatic cancers. There are various molecular mechanisms involved in multidrug resistance, including change in the activity of membrane transporters (such as ABC transporters), increase of drug metabolism, change of the target enzyme (such as mutations that change thymidylate synthase and topoisomerases), promotion of DNA damage repair, and escape from drug induced apoptosis. Clinical and laboratory investigations on biomarkers involved in the response to chemotherapy have characterized the key factors behind the failure of treatments. Knowing the molecular factors involved in drug resistance may help us to develop new strategies for more promising chemotherapy and reduce the rate of relapse. In this brief review, molecular mechanisms and tumor microenvironment leading to decreased drug sensitivity, and strategies of reversing drug resistance are described.
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Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Resistencia a Múltiples Medicamentos/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Neoplasias/tratamiento farmacológico , Animales , Humanos , Proteínas de Transporte de Membrana/metabolismo , Neoplasias/metabolismo , Microambiente Tumoral/efectos de los fármacosRESUMEN
CONTEXT: Liposomes are increasingly employed to deliver chemotherapeutic agents, antisense oligonucleotides, and genes to various therapeutic targets. OBJECTIVE: The present investigation evaluates the ability of fusogenic pH-sensitive liposomes of rapamycin in increasing its antiproliferative effect on human breast adenocarcinoma (MCF-7) cell line. MATERIALS AND METHODS: Cholesterol (Chol) and dipalmitoylphosphatidylcholine (DPPC) (DPPC:Chol, 7:3) were used to prepare conventional rapamycin liposomes by a modified ethanol injection method. Dioleoylphosphatidylethanolamine (DOPE) was used to produce fusogenic and pH-sensitive properties in liposomes simultaneously (DPPC:Chol:DOPE, 7:3:4.2). The prepared liposomes were characterized by their size, zeta potential, encapsulation efficiency percent (EE%), and chemical stability during 6 months. The antiproliferative effects of both types of rapamycin liposomes (10, 25, and 50 nmol/L) with optimized formulations were assessed on MCF-7 cells, as cancerous cells, and human umbilical vein endothelial cells (HUVEC), as healthy cells, employing the diphenyltetrazolium bromide (MTT) assay for 72 h. RESULTS AND DISCUSSION: The particle size, zeta potential, and EE% of the liposomes were 165 ± 12.3 and 178 ± 15.4 nm, -39.6 ± 1.3, and -41.2 ± 2.1 mV as well as 76.9 ± 2.6 and 76.9 ± 2.6% in conventional and fusogenic pH-sensitive liposomes, respectively. Physicochemical stability results indicated that both liposome types were relatively stable at 4 °C than 25 °C. In vitro antiproliferative evaluation showed that fusogenic pH-sensitive liposomes had better antiproliferative effects on MCF-7 cells compared to the conventional liposomes. Conversely, fusogenic pH-sensitive liposomes had less cytotoxicity on HUVEC cell line.