RESUMO
BACKGROUND: Merkel cell carcinoma (MCC) is an aggressive malignant neuroendocrine tumour. There are two subsets of MCC, one related to Merkel cell polyomavirus (MCPyV) and the other to ultraviolet radiation (UVR). MCPyV-positive and MCPyV-negative MCCs have been considered to be different tumours, as the former harbour few DNA mutations and are not related to UVR, and the latter usually arise in sun-exposed areas and may be found in conjunction with other keratinocytic tumours, mostly squamous cell carcinomas. Two viral oncoproteins, large T antigen (LT; coded by MCPyV_gp3) and small T antigen (sT; coded by MCPyV_gp4), promote different carcinogenic pathways. OBJECTIVES: To determine which genes are differentially expressed in MCPyV-positive and MCPyV-negative MCC; to describe the mutational burden and the most frequently mutated genes in both MCC subtypes; and to identify the clinical and molecular factors that may be related to patient survival. METHODS: Ninety-two patients with a diagnosis of MCC were identified from the medical databases of participating centres. To study gene expression, a customized panel of 172 genes was developed. Gene expression profiling was performed with nCounter technology. For mutational studies, a customized panel of 26 genes was designed. Somatic single nucleotide variants (SNVs) were identified following the GATK Best Practices workflow for somatic mutations. RESULTS: The expression of LT enabled the series to be divided into two groups (LT positive, n = 55; LT negative, n = 37). Genes differentially expressed in LT-negative patients were related to epithelial differentiation, especially SOX9, or proliferation and the cell cycle (MYC, CDK6), among others. Congruently, LT displayed lower expression in SOX9-positive patients, and differentially expressed genes in SOX9-positive patients were related to epithelial/squamous differentiation. In LT-positive patients, the mean SNV frequency was 4.3; in LT-negative patients it was 10 (P = 0.03). On multivariate survival analysis, the expression of SNAI1 [hazard ratio (HR) 1.046, 95% confidence interval (CI) 1.007-1.086; P = 0.02] and CDK6 (HR 1.049, 95% CI 1.020-1.080; P = 0.001) were identified as risk factors. CONCLUSIONS: Tumours with weak LT expression tend to co-express genes related to squamous differentiation and the cell cycle, and to have a higher mutational burden. These findings are congruent with those of earlier studies.
Merkel cell carcinoma (MCC) is an aggressive form of skin tumour. There are two subtypes of MCC: one of them is related to a virus called Merkel cell polyomavirus (MCPyV); the other one is related to persistent exposure to sunlight. The aim of this research was to find differences between these subtypes in their molecular behaviour (the genes that are expressed and the mutations that may be found). To do this, we carried out two studies, one to investigate gene expression (the process cells use to convert the instructions in our DNA into a functional product such as a protein) and one to look at gene mutations (changes in the DNA sequence). We found that the tumours that were not related to MCPyV expressed genes related to epithelial differentiation (the process by which unspecialized cells gain features characteristics of epithelial cells, which, among other things, make up the outer surface of the body), which means that the origin of both MCC subtypes may be different. We also found that MCPyV-related tumours had fewer mutations. Our findings are important because they help us to understand the biology of the MCC subtypes and could help with the development of new treatments for people diagnosed with skin tumours.
Assuntos
Antígenos Virais de Tumores , Carcinoma de Célula de Merkel , Poliomavírus das Células de Merkel , Infecções por Polyomavirus , Fatores de Transcrição SOX9 , Neoplasias Cutâneas , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Antígenos Virais de Tumores/genética , Carcinoma de Célula de Merkel/virologia , Carcinoma de Célula de Merkel/genética , Carcinoma de Célula de Merkel/patologia , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Poliomavírus das Células de Merkel/genética , Poliomavírus das Células de Merkel/isolamento & purificação , Mutação , Infecções por Polyomavirus/genética , Infecções por Polyomavirus/virologia , Neoplasias Cutâneas/virologia , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Fatores de Transcrição SOX9/genética , Infecções Tumorais por Vírus/genética , Infecções Tumorais por Vírus/virologiaAssuntos
Fenótipo , Neoplasias Cutâneas , Humanos , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/imunologia , Masculino , Linfoma de Células T Periférico/genética , Linfoma de Células T Periférico/patologia , Linfoma de Células T Periférico/imunologia , Feminino , Pessoa de Meia-Idade , Transtornos Linfoproliferativos/genética , Transtornos Linfoproliferativos/patologia , Transtornos Linfoproliferativos/imunologia , Idoso , Linfócitos T CD4-Positivos/imunologia , Mutação , Adulto , Células T Auxiliares Foliculares/imunologia , Diagnóstico Diferencial , Análise Mutacional de DNA , Linfoma Cutâneo de Células T/genética , Linfoma Cutâneo de Células T/patologia , Linfoma Cutâneo de Células T/imunologiaRESUMO
Tumor organoids are three-dimensional (3D) ex vivo tumor models that recapitulate the biological key features of the original primary tumor tissues. Patient-derived tumor organoids have been used in translational cancer research and can be applied to assess treatment sensitivity and resistance, cell-cell interactions, and tumor cell interactions with the tumor microenvironment. Tumor organoids are complex culture systems that require advanced cell culture techniques and culture media with specific growth factor cocktails and a biological basement membrane that mimics the extracellular environment. The ability to establish primary tumor cultures highly depends on the tissue of origin, the cellularity, and the clinical features of the tumor, such as the tumor grade. Furthermore, tissue sample collection, material quality and quantity, as well as correct biobanking and storage are crucial elements of this procedure. The technical capabilities of the laboratory are also crucial factors to consider. Here, we report a validated SOP/protocol that is technically and economically feasible for the culture of ex vivo tumor organoids from fresh tissue samples of pancreatic adenocarcinoma origin, either from fresh primary resected patient donor tissue or patient-derived xenografts (PDX). The technique described herein can be performed in laboratories with basic tissue culture and mouse facilities and is tailored for wide application in the translational oncology field.
Assuntos
Adenocarcinoma , Neoplasias Pancreáticas , Humanos , Animais , Camundongos , Bancos de Espécimes Biológicos , Fibroblastos , Organoides , Microambiente Tumoral , Neoplasias PancreáticasRESUMO
Ultrasounds (US) are a non-ionizing mechanical wave, with less adverse effects than conventional pharmacological or surgical treatments. Different biological effects are induced in tissues and cells by ultrasound actuation depending on acoustic parameters, such as the wave intensity, frequency and treatment dose. This non-ionizing radiation has considerable applications in biomedicine including surgery, medical imaging, physical therapy and cancer therapy. Depending on the wave intensity, US are applied as high-intensity ultrasounds (HIUS) and low-intensity pulsed ultrasounds (LIPUS), with different effects on cells and tissues. HIUS produce thermal and mechanical effects, resulting in a large localized temperature increase, leading to tissue ablation and even tumor necrosis. This can be achieved by focusing low intensity waves emitted from different electrically shifted transducers, known as high-intensity focused ultrasounds (HIFU). LIPUS have been used extensively as a therapeutic, surgical and diagnostic tool, with diverse biological effects observed in tissues and cultured cells. US represent a non-invasive treatment strategy that can be applied to selected areas of the body, with limited adverse effects. In fact, tumor ablation using HIFU has been used as a curative treatment in patients with an early-stage pancreatic tumor and is an effective palliative treatment in patients with advanced stage disease. However, the biological effects, dose standardization, benefit-risk ratio and safety are not fully understood. Thus, it is an emerging field that requires further research in order to reach its full potential.