RESUMEN
Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous group of tumors usually diagnosed at an advanced stage and characterized by a poor prognosis. The main risk factors associated with its development include tobacco and alcohol consumption and Human Papillomavirus (HPV) infections. The immune system has a significant role in the oncogenesis and evolution of this cancer type. Notably, the immunosuppressive tumor microenvironment triggers immune escape through several mechanisms. The improved understanding of the antitumor immune response in solid tumors and the role of the immune checkpoint molecules and other immune regulators have led to the development of novel therapeutic strategies that revolutionized the clinical management of HNSCC. However, the limited overall response rate to immunotherapy urges identifying predictive biomarkers of response and resistance to treatment. Here, we review the role of the immune system and immune checkpoint pathways in HNSCC, the most relevant clinical findings linked to immunotherapeutic strategies and predictive biomarkers of response and future treatment perspectives.
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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)
Asunto(s)
Humanos , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas/genética , Sistemas CRISPR-Cas/genética , Biotecnología , Terapia Genética/métodos , Expresión Génica , Genoma Humano/genética , Regulación de la Expresión Génica , Epigenómica/tendencias , Proteínas Asociadas a CRISPR/genética , Proteínas Asociadas a CRISPR/uso terapéutico , Enfermedades Genéticas Congénitas/terapia , Neoplasias/terapiaRESUMEN
CRISPR-Cas12a (also called Cpf1) has been commonly used for genomic editing, based on its ability to generate precise double-stranded DNA (dsDNA) breaks. Recently, it was demonstrated that Cas12a exhibits unspecific ssDNAse activity upon target recognition. This feature allows CRISPR-Cas to be coupled with a ssDNA reporter and generate a fast, accurate and ultrasensitive molecular detection method. Here, we demonstrate that Cas12a was able to detect DNA target sequences corresponding to carbapenemases resistance genes such as KPC, NDM and OXA. Also, with the addition of a reverse-transcription step, we were able to detect viral RNA sequences from DENV, ZIKV and HANTV genomes. In all cases, assay run time was less than two hours. Additionally, we report attomolar levels of detection. This methodology was validated using clinical samples from patients infected with Dengue virus. Reactions were visualized by detection of a fluorescent signal, as well as by the use of a simple lateral flow strip. These results indicate that Cas12a is able to detect both DNA and RNA targets, making it an appropriate and convenient tool to detect all types of pathogens.
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Proteínas Bacterianas/genética , Proteínas Bacterianas/farmacología , Proteínas Asociadas a CRISPR/genética , Sistemas CRISPR-Cas , Farmacorresistencia Bacteriana/genética , Endodesoxirribonucleasas/genética , Edición Génica/métodos , Virus ARN/genética , beta-Lactamasas/farmacología , ADN de Cadena Simple/genética , Dengue/virología , Virus del Dengue/genética , Colorantes Fluorescentes , Virus Hantaan/genética , Humanos , Técnicas de Diagnóstico Molecular , Virus ARN/patogenicidad , ARN Viral/genética , Virus Zika/genéticaRESUMEN
Nowadays, histopathological criteria for melanocytic lesions are the mainstay prognostic factors for melanoma. However, there are cases in which these parameters fall short to predict melanoma spread. We recently demonstrated a correlation of cofilin-1 levels, a key protein for tumor invasion, with different histopathological parameters associated with melanoma malignancy as well as a negative correlation with survival. In order to broaden our previous findings, we aim to estimate the probability of a melanoma to metastasize as a function of both a conventional histopathological parameter (Breslow thickness, BT) and cofilin-1's immunohistochemical expression levels, which we propose as a potential marker for metastasis. We used a Bayesian approach to analyze clinical and cofilin-1 datasets formerly obtained from a patients' small cohort diagnosed with malignant melanocytic lesions since 2000 until 2008; classified at different tumor stages with or without detected metastasis and with at least 5 years of clinical follow-up. Low BT values exhibited wide variance to predict metastasis occurrence, while the differential diagnostic value of cofilin-1 confirmed BT diagnosis or resulted more precise to predict outcome. Particularly, the probability of metastasis estimation improved when cofilin-1 was combined with BT for specific cases, where BT displayed large uncertainties. Our analysis and the cofilin-1 determination provided statistically significant prognostic value in mid-low BT melanomas, which could complement further evaluation criteria to assist diagnosis and treatment decision-making. Moreover, the combined use of cofilin-1 with BT, if validated in follow-up studies, would be feasible to help patients' selection for treatment and optimize health resources.
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Cofilina 1/metabolismo , Melanoma/diagnóstico , Metástasis de la Neoplasia/diagnóstico , Neoplasias Cutáneas/diagnóstico , Anciano , Anciano de 80 o más Años , Argentina , Biomarcadores de Tumor/metabolismo , Femenino , Humanos , Masculino , Melanoma/metabolismo , Melanoma/patología , Persona de Mediana Edad , Metástasis de la Neoplasia/patología , Estadificación de Neoplasias , Pronóstico , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/patologíaRESUMEN
Abstract: The growth factor receptor c-kit (CD117) is expressed in immature T-cells and in some advanced forms of mycosis fungoides. c-kit gene mutation results in unrestricted neoplastic proliferation. We aimed to detect by PCR the most frequent exon mutations in seventeen plaque-stage MF patients, in their perilesional skin and in healthy skin donors. We secondarily evaluated CD117 expression by immunohistochemistry in plaque-stage and tumor-stage MF. We detected no mutation in c-kit gene and low CD117 expression was confirmed on atypical cells in one patient. Complete c-kit exon and intron sequences should be assessed and more sensitive sequencing method could be also applied.
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Humanos , Masculino , Femenino , Anciano , Exones/genética , Micosis Fungoide/genética , Proteínas Proto-Oncogénicas c-kit/genética , Mutación/genética , Inmunohistoquímica , Estudios de Casos y Controles , Expresión Génica , Reacción en Cadena de la Polimerasa , Estudios ProspectivosRESUMEN
The growth factor receptor c-kit (CD117) is expressed in immature T-cells and in some advanced forms of mycosis fungoides. c-kit gene mutation results in unrestricted neoplastic proliferation. We aimed to detect by PCR the most frequent exon mutations in seventeen plaque-stage MF patients, in their perilesional skin and in healthy skin donors. We secondarily evaluated CD117 expression by immunohistochemistry in plaque-stage and tumor-stage MF. We detected no mutation in c-kit gene and low CD117 expression was confirmed on atypical cells in one patient. Complete c-kit exon and intron sequences should be assessed and more sensitive sequencing method could be also applied.
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Exones/genética , Mutación/genética , Micosis Fungoide/genética , Proteínas Proto-Oncogénicas c-kit/genética , Anciano , Estudios de Casos y Controles , Femenino , Expresión Génica , Humanos , Inmunohistoquímica , Masculino , Reacción en Cadena de la Polimerasa , Estudios ProspectivosRESUMEN
Melanoma is an aggressive cancer with highly metastatic ability. We propose cofilin-1, a key protein in the regulation of actin dynamics and migration, as a prognostic marker. We determined cofilin-1 levels in a retrospective cohort of patients with melanomas and benign lesions of melanocytes (nevi) by immunohistochemistry. Higher cofilin-1 levels were found in malignant melanoma (MM) with Breslow Index (BI)>2 vs MM with BI<2, melanoma in situ (MIS) and nevi and also in MM with metastasis vs MM without detected metastasis. Kaplan-Meier survival curves were performed, clustering patients according to either the type of melanocytic lesions or cofilin-1 level. Survival curves demonstrated worse prognosis of patients with high vs low cofilin-1 levels. TCGA database analysis of melanoma also showed low survival in patients with upregulated cofilin-1 mRNA vs patients without alteration in CFL1 mRNA expression. As cofilin-1 has a dual function depending on its intracellular localization, we evaluated nuclear and cytoplasmic levels of cofilin-1 in melanoma and nevi samples by immunofluorescence. MM with high Breslow index and metastatic cells not only presented cytoplasmic cofilin-1, but also showed this protein at the nucleus. An increase in nuclear/cytoplasmic cofilin-1 mean fluorescence ratio was observed in MM with BI>2 vs MM with BI<2, MIS and nevi. In conclusion, an association of cofilin-1 levels with malignant features and an inverse correlation with survival were demonstrated. Moreover, this study suggests that not only the higher levels of cofilin-1, but also its nuclear localization can be proposed as marker of worse outcome of patients with melanoma.
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Several glycoproteins in mammalian brains contain α2,8-linked disialic acid residues. We previously showed a constant expression of disialic acid (DiSia) in the hippocampus, olfactory bulb and cortex, and a gradual decrease of expression in the cerebellum from neonatal to senile mice. Previous publications indicate that neurite extension of neuroblastoma-derived Neuro2A cells is inhibited in the presence of DiSia antibody. Based on this, we treated Neuro2A cell cultures with RNA interference for ST8SiaIII mRNA, the enzyme responsible for DiSia formation. We observed that neurite extension was inhibited by this treatment. Taking this evidence into consideration and the relationship of the cerebellum with learning and memory, we studied the role of DiSia expression in a learning task. Through delivery of pST8SiaIII into the brains of C57BL/6 neonatal mice, we inhibited the expression of ST8SiaIII. ST8SiaIII mRNA and protein expressions were analyzed by real-time PCR and western blot, respectively. In this work, we showed that pST8SiaIII-treated mice presented a significantly reduced level of ST8SiaIII mRNA in the cerebellum (p<0.01) in comparison to control mice at 8 days after treatment. It is also noted that these levels returned to baseline values in the adulthood. Then, we evaluated behavioural performance in the T-Maze, a learning task that estimates procedural memory. At all ages, pST8SiaIII-treated mice showed a lower performance in the test session, being most evident at older ages (p<0.001). Taken all together, we conclude that gene expression of ST8SiaIII is necessary for some cognitive tasks at early postnatal ages, since reduced levels impaired procedural memory in adult mice.
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Encéfalo/enzimología , Trastornos de la Memoria/enzimología , Sialiltransferasas/antagonistas & inhibidores , Animales , Animales Recién Nacidos , Secuencia de Bases , Western Blotting , Línea Celular , Cartilla de ADN , Electroforesis en Gel de Poliacrilamida , Aprendizaje por Laberinto , Ratones , Ratones Endogámicos C57BL , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
It is known that disialic acids (diSia) are present in the mammalian brain. However, the precise anatomical distribution and the chronology of its expression along life are not well studied yet. It is accepted that the transfer of diSia in the brain is mediated mainly by the enzyme ST8Sia III (α2,8-sialyltransferase III). We studied the expression of diSia glycoepitopes and of the ST8Sia III gene in different structures of the mouse brain at different postnatal stages by immunohistochemistry and real-time polymerase chain reaction, respectively. C57BL/6 mice of different stages were used. Samples of hippocampus, olfactory bulb, cortex and cerebellum were processed for studies of molecular biology and immunohistochemistry. Histological analysis revealed an important decrease in diSia labeling in the senile cerebellum compared with other structures and stages (P ⪠0.001). In concordance with these results, a significant decrease in ST8Sia III gene expression was found in the cerebellum of senile animals (P < 0.001). These results suggest that diSia are constantly expressed but with differential expression in various areas of the mouse central nervous system. On the other hand, the concordance in the decreased expression of ST8Sia III and the diSia epitope in the cerebellum of senile animals suggest a role of diSia in this structure or, inversely, an influence of aging on the expression of diSia in the cerebellum. Further research in that direction could elucidate the roles of diSia in brain function in health and disease.