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1.
Int J Biol Markers ; 37(2): 113-122, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35473449

RESUMO

Skin tumours are among the cancer types most sensitive to immunotherapy, due to their unique immunogenic features including skin-associated lymphoid tissue, high mutational load, overexpression of tumour antigens, and high frequency of viral antigens. Despite this high immunotherapy response rate, however, ultimately most skin tumours develop similar treatment resistance to most other malignant tumours, which highlights the need for in-depth study of mechanisms of response and resistance to immunotherapy. A bibliographic review of the most recent publications regarding currently in use and emerging biomarkers on skin tumors has been done. Predictive biomarkers of treatment response, biomarkers that warn of possible resistance, and emerging markers, the majority of a systemic nature, are described. Including factors affecting not only genomics, but also the immune system, nervous system, microbiota, tumour microenvironment, metabolism and stress. For accurate diagnosis of tumour type, knowledge of its functional mechanisms and selection of a comprehensive therapeutic protocol, this inclusive view of biology, health and disease is fundamental. This field of study could also become a valuable source of practical information applicable to other areas of oncology and immunotherapy.


Assuntos
Neoplasias , Neoplasias Cutâneas , Antígenos de Neoplasias , Biomarcadores Tumorais/metabolismo , Humanos , Imunoterapia , Neoplasias/terapia , Neoplasias Cutâneas/terapia , Microambiente Tumoral
2.
RNA Biol ; 16(3): 295-308, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30734641

RESUMO

Viroids are small infectious, non-protein-coding circular RNAs that replicate independently and, in some cases, incite diseases in plants. They are classified into two families: Pospiviroidae, composed of species that have a central conserved region (CCR) and replicate in the cell nucleus, and Avsunviroidae, containing species that lack a CCR and whose multimeric replicative intermediates of either polarity generated in plastids self-cleave through hammerhead ribozymes. The compact, rod-like or branched, secondary structures of viroid RNAs have been predicted by RNA folding algorithms and further examined using different in vitro and in vivo experimental techniques. However, direct data about their native tertiary structure remain scarce. Here we have applied atomic force microscopy (AFM) to image at single-molecule resolution different variant RNAs of three representative viroids: potato spindle tuber viroid (PSTVd, family Pospiviroidae), peach latent mosaic viroid and eggplant latent viroid (PLMVd and ELVd, family Avsunviroidae). Our results provide a direct visualization of their native, three-dimensional conformations at 0 and 4 mM Mg2+ and highlight the role that some elements of tertiary structure play in their stabilization. The AFM images show that addition of 4 mM Mg2+ to the folding buffer results in a size contraction in PSTVd and ELVd, as well as in PLMVd when the kissing-loop interaction that stabilizes its 3D structure is preserved.


Assuntos
Microscopia de Força Atômica , Conformação de Ácido Nucleico , RNA Viral/química , Imagem Individual de Molécula , Viroides/genética , Microscopia de Força Atômica/métodos , Vírus de Plantas/genética , Vírus de Plantas/ultraestrutura , Imagem Individual de Molécula/métodos
3.
Virus Res ; 209: 136-45, 2015 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-25738582

RESUMO

The discovery of viroids about 45 years ago heralded a revolution in Biology: small RNAs comprising around 350 nt were found to be able to replicate autonomously-and to incite diseases in certain plants-without encoding proteins, fundamental properties discriminating these infectious agents from viruses. The initial focus on the pathological effects usually accompanying infection by viroids soon shifted to their molecular features-they are circular molecules that fold upon themselves adopting compact secondary conformations-and then to how they manipulate their hosts to be propagated. Replication of viroids-in the nucleus or chloroplasts through a rolling-circle mechanism involving polymerization, cleavage and circularization of RNA strands-dealt three surprises: (i) certain RNA polymerases are redirected to accept RNA instead of their DNA templates, (ii) cleavage in chloroplastic viroids is not mediated by host enzymes but by hammerhead ribozymes, and (iii) circularization in nuclear viroids is catalyzed by a DNA ligase redirected to act upon RNA substrates. These enzymes (and ribozymes) are most probably assisted by host proteins, including transcription factors and RNA chaperones. Movement of viroids, first intracellularly and then to adjacent cells and distal plant parts, has turned out to be a tightly regulated process in which specific RNA structural motifs play a crucial role. More recently, the advent of RNA silencing has brought new views on how viroids may cause disease and on how their hosts react to contain the infection; additionally, viroid infection may be restricted by other mechanisms. Representing the lowest step on the biological size scale, viroids have also attracted considerable interest to get a tentative picture of the essential characteristics of the primitive replicons that populated the postulated RNA world.


Assuntos
Interações Hospedeiro-Patógeno , Doenças das Plantas/virologia , Plantas/virologia , Replicon , Viroides/fisiologia , Conformação de Ácido Nucleico , Viroides/genética
4.
Mol Hum Reprod ; 19(2): 102-8, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23100464

RESUMO

Mutations in the spindle checkpoint genes can cause improper chromosome segregations and aneuploidies, which in turn may lead to reproductive problems. Two of the proteins involved in this checkpoint are Aurora kinase B (AURKB), preventing the anaphase whenever microtubule-kinetochore attachments are not the proper ones during metaphase; and synaptonemal complex protein 3 (SYCP3), which is essential for the formation of the complex and for the recombination of the homologous chromosomes. This study has attempted to clarify the possible involvement of both proteins in the reproductive problems of patients with chromosomal instability. In order to do this, we have performed a screening for genetic variants in AURKB and SYCP3 among these patients using Sanger sequencing. Only one apparently non-pathogenic deletion was found in SYCP3. On the other hand, we found six sequence variations in AURKB. The consequences of these changes on the protein were studied in silico using different bioinformatic tools. In addition, the frequency of three of the variations was studied using a high-resolution melting approach. The absence of these three variants in control samples and their position in the AURKB gene suggests their possible involvement in the patients' chromosomal instability. Interestingly, two of the identified changes in AURKB were found in each member of a couple with antecedents of spontaneous pregnancy loss, a fetal anencephaly and a deaf daughter. One of these changes is described here for the first time. Although further studies are necessary, our results are encouraging enough to propose the analysis of AURKB in couples with reproductive problems.


Assuntos
Proteínas Nucleares/genética , Proteínas Serina-Treonina Quinases/genética , Reprodução/fisiologia , Aurora Quinase B , Aurora Quinases , Proteínas de Ciclo Celular , Instabilidade Cromossômica/genética , Proteínas de Ligação a DNA , Feminino , Humanos , Masculino , Mutação , Gravidez , Reprodução/genética
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