Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 198
Filtrar
1.
Cell ; 174(6): 1537-1548.e29, 2018 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-30122351

RESUMO

LINE-1 retrotransposition is tightly restricted by layers of regulatory control, with epigenetic pathways being the best characterized. Looking at post-transcriptional regulation, we now show that LINE-1 mRNA 3' ends are pervasively uridylated in various human cellular models and in mouse testes. TUT4 and TUT7 uridyltransferases catalyze the modification and function in cooperation with the helicase/RNPase MOV10 to counteract the RNA chaperone activity of the L1-ORF1p retrotransposon protein. Uridylation potently restricts LINE-1 retrotransposition by a multilayer mechanism depending on differential subcellular localization of the uridyltransferases. We propose that uridine residues added by TUT7 in the cytoplasm inhibit initiation of reverse transcription of LINE-1 mRNAs once they are reimported to the nucleus, whereas uridylation by TUT4, which is enriched in cytoplasmic foci, destabilizes mRNAs. These results provide a model for the post-transcriptional restriction of LINE-1, revealing a key physiological role for TUT4/7-mediated uridylation in maintaining genome stability.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas Nucleares/metabolismo , RNA Nucleotidiltransferases/metabolismo , Proteínas de Ligação a RNA/metabolismo , Uridina/metabolismo , Animais , Proteínas de Ligação a DNA/antagonistas & inibidores , Proteínas de Ligação a DNA/genética , Células HEK293 , Humanos , Camundongos , Proteínas Nucleares/genética , Ligação Proteica , RNA Helicases/antagonistas & inibidores , RNA Helicases/genética , RNA Helicases/metabolismo , Interferência de RNA , RNA Nucleotidiltransferases/antagonistas & inibidores , RNA Nucleotidiltransferases/genética , Estabilidade de RNA , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/genética , Retroelementos/genética
2.
Genes Dev ; 35(17-18): 1290-1303, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34385261

RESUMO

Biogenesis of most eukaryotic mRNAs involves the addition of an untemplated polyadenosine (pA) tail by the cleavage and polyadenylation machinery. The pA tail, and its exact length, impacts mRNA stability, nuclear export, and translation. To define how polyadenylation is controlled in S. cerevisiae, we have used an in vivo assay capable of assessing nuclear pA tail synthesis, analyzed tail length distributions by direct RNA sequencing, and reconstituted polyadenylation reactions with purified components. This revealed three control mechanisms for pA tail length. First, we found that the pA binding protein (PABP) Nab2p is the primary regulator of pA tail length. Second, when Nab2p is limiting, the nuclear pool of Pab1p, the second major PABP in yeast, controls the process. Third, when both PABPs are absent, the cleavage and polyadenylation factor (CPF) limits pA tail synthesis. Thus, Pab1p and CPF provide fail-safe mechanisms to a primary Nab2p-dependent pathway, thereby preventing uncontrolled polyadenylation and allowing mRNA export and translation.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Poliadenilação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
3.
Nucleic Acids Res ; 52(8): 4723-4738, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38587192

RESUMO

Bacterial reverse transcriptases (RTs) are a large and diverse enzyme family. AbiA, AbiK and Abi-P2 are abortive infection system (Abi) RTs that mediate defense against bacteriophages. What sets Abi RTs apart from other RT enzymes is their ability to synthesize long DNA products of random sequences in a template- and primer-independent manner. Structures of AbiK and Abi-P2 representatives have recently been determined, but there are no structural data available for AbiA. Here, we report the crystal structure of Lactococcus AbiA polymerase in complex with a single-stranded polymerization product. AbiA comprises three domains: an RT-like domain, a helical domain that is typical for Abi polymerases, and a higher eukaryotes and prokaryotes nucleotide-binding (HEPN) domain that is common for many antiviral proteins. AbiA forms a dimer that distinguishes it from AbiK and Abi-P2, which form trimers/hexamers. We show the DNA polymerase activity of AbiA in an in vitro assay and demonstrate that it requires the presence of the HEPN domain which is enzymatically inactive. We validate our biochemical and structural results in vivo through bacteriophage infection assays. Finally, our in vivo results suggest that AbiA-mediated phage defense may not rely on AbiA-mediated cell death.


Assuntos
Bacteriófagos , Lactococcus , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Bacteriófagos/genética , Cristalografia por Raios X , Lactococcus/virologia , Lactococcus/genética , Modelos Moleculares , Domínios Proteicos , Multimerização Proteica , DNA Polimerase Dirigida por RNA/metabolismo , DNA Polimerase Dirigida por RNA/química , DNA Polimerase Dirigida por RNA/genética , Relação Estrutura-Atividade
4.
Int J Mol Sci ; 25(8)2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38673793

RESUMO

Lung cancer has become a major public health concern, standing as the leading cause of cancer-related deaths worldwide. Among its subtypes, small-cell lung cancer (SCLC) is characterized by aggressive and rapid growth, poor differentiation, and neuroendocrine features. Typically, SCLC is diagnosed at an advanced stage (extensive disease, ED-SCLC), with distant metastases, and is strongly associated with tobacco smoking and has a poor prognosis. Recent clinical trials, such as CASPIAN and IMpower133, have demonstrated promising outcomes with the incorporation of immune checkpoint inhibitors in first-line chemotherapy, leading to prolonged progression-free survival and overall survival in patients with ED-SCLC compared to standard chemotherapy. Other studies have emphasized the potential for future development of molecularly targeted therapies in SCLC patients, including inhibitors of IGF-1R, DLL3, BCL-2, MYC, or PARP. The molecular subdivision of SCLC based on transcriptomic and immunohistochemical analyses represents a significant advancement in both diagnostic and clinical approaches in SCLC patients. Specific molecular pathways are activated within distinct transcriptome subtypes of SCLC, offering the potential for personalized treatment strategies, such as targeted therapies and immunotherapies. Such tailored approaches hold promise for significantly improving outcomes in SCLC patients.


Assuntos
Neoplasias Pulmonares , Medicina de Precisão , Carcinoma de Pequenas Células do Pulmão , Humanos , Carcinoma de Pequenas Células do Pulmão/genética , Carcinoma de Pequenas Células do Pulmão/terapia , Carcinoma de Pequenas Células do Pulmão/patologia , Carcinoma de Pequenas Células do Pulmão/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/terapia , Neoplasias Pulmonares/tratamento farmacológico , Medicina de Precisão/métodos , Terapia de Alvo Molecular , Biomarcadores Tumorais/metabolismo , Imunoterapia/métodos
5.
Int J Mol Sci ; 25(11)2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38892080

RESUMO

Endometrial cancer (EC) accounts for 90% of uterine cancer cases. It is considered not only one of the most common gynecological malignancies but also one of the most frequent cancers among women overall. Nowadays, the differentiation of EC subtypes is based on immunohistochemistry and molecular techniques. It is considered that patients' prognosis and the implementation of the appropriate treatment depend on the cancer subtype. Patients with pathogenic variants in POLE have the most favorable outcome, while those with abnormal p53 protein have the poorest. Therefore, in patients with POLE mutation, the de-escalation of postoperative treatment may be considered, and patients with abnormal p53 protein should be subjected to intensive adjuvant therapy. Patients with a DNA mismatch repair (dMMR) deficiency are classified in the intermediate prognosis group as EC patients without a specific molecular profile. Immunotherapy has been recognized as an effective treatment method in patients with advanced or recurrent EC with a mismatch deficiency. Thus, different adjuvant therapy approaches, including targeted therapy and immunotherapy, are being proposed depending on the EC subtype, and international guidelines, such as those published by ESMO and ESGO/ESTRO/ESP, include recommendations for performing the molecular classification of all EC cases. The decision about adjuvant therapy selection has to be based not only on clinical data and histological type and stage of cancer, but, following international recommendations, has to include EC molecular subtyping. This review describes how molecular classification could support more optimal therapeutic management in endometrial cancer patients.


Assuntos
Neoplasias do Endométrio , Humanos , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/classificação , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/terapia , Neoplasias do Endométrio/metabolismo , Feminino , Imunoterapia/métodos , Mutação , Reparo de Erro de Pareamento de DNA/genética , Prognóstico , Biomarcadores Tumorais/genética
6.
Cancer Immunol Immunother ; 72(12): 4169-4177, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37816808

RESUMO

INTRODUCTION: PD-L1 (Programmed Cell Death Ligand 1) is currently the only recognised marker of response to immunotherapy with anti-PD-1 or anti-PD-L1 antibodies in patients with advanced non-small cell lung cancer (NSCLC). However, this marker is not perfect. Soluble PD-L1 (sPD-L1) may be a novel predictor of immunotherapy efficacy in NSCLC patients. MATERIAL AND METHODS: We enrolled 120 patients (median age 68 ± 6.81 years, 70 males and 50 females) with locally advanced (stage IIIB; 10 patients) or advanced (stage IV; 110 patients) NSCLC. PD-L1 expression in tumour cells was assessed by immunohistochemistry (IHC) in 117 (97.5%) patients. The soluble PD-L1 concentration in plasma samples was measured using enzyme-linked immunosorbent assay (ELISA). The response to immunotherapy, progression-free survival (PFS), and overall survival (OS), calculated from the start of immunotherapy, were assessed in 119 patients. RESULTS: Patients with disease control had significantly lower (p = 0.0006) concentrations of sPD-L1 in blood plasma than patients with progression during the first months of immunotherapy or chemoimmunotherapy Patients with ≥ 6 month progression-free survival had a significantly higher (p = 0.013) percentage of tumor cells with PD-L1 expression than patients with shorter PFS. Patients with ≥ 6 months OS had significantly lower (p = 0.0142) plasma sPD-L1 concentrations than those with shorter overall survival. The median PFS was significantly higher in patients with low sPD-L1 concentrations than in those with high concentrations of this protein (5.8 vs. 2.5 months, HR = 0.6021, p = 0.0156). Similarly, patients with low sPD-L1 levels had a significantly higher median overall survival than those with sPD-L1 levels above the median (16.5 vs. 7 months, HR = 0.5354, p = 0.0071). There was no significant correlation between the percentage of tumour cells expressing PD-L1 and the concentration of sPD-L1 in the blood plasma. CONCLUSION: High sPD-L1 concentration is a negative predictor of immunotherapy efficacy in patients with NSCLC. It is worthwhile to determine sPD-L1 concentration to predict the risk of resistance to anti-PD-1 or anti-PD-L1 antibodies with greater certainty.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Masculino , Feminino , Humanos , Pessoa de Meia-Idade , Idoso , Neoplasias Pulmonares/metabolismo , Antígeno B7-H1/metabolismo , Prognóstico , Imunoterapia
7.
Eur J Anaesthesiol ; 40(10): 724-736, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37218626

RESUMO

INTRODUCTION: Cardiac arrest in the operating room is a rare but potentially life-threatening event with mortality rates of more than 50%. Contributing factors are often known, and the event is recognised rapidly as patients are usually under full monitoring. This guideline covers the perioperative period and is complementary to the European Resuscitation Council (ERC) guidelines. MATERIAL AND METHODS: The European Society of Anaesthesiology and Intensive Care and the European Society for Trauma and Emergency Surgery jointly nominated a panel of experts to develop guidelines for the recognition, treatment and prevention of cardiac arrest in the perioperative period. A literature search was conducted in MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials. All searches were restricted to publications from 1980 to 2019 inclusive and to the English, French, Italian and Spanish languages. The authors also contributed individual, independent literature searches. RESULTS: This guideline contains background information and recommendation for the treatment of cardiac arrest in the operating room environment, and addresses controversial topics such as open chest cardiac massage (OCCM), resuscitative endovascular balloon occlusion (REBOA) and resuscitative thoracotomy, pericardiocentesis, needle decompression and thoracostomy. CONCLUSION: Successful prevention and management of cardiac arrest during anaesthesia and surgery requires anticipation, early recognition and a clear treatment plan. The ready availability of expert staff and equipment must also be taken into consideration. Success not only depends on medical knowledge, technical skills and a well organised team using crew resource management but also on an institutional safety culture embedded in everyday practice through continuous education, training and multidisciplinary co-operation.


Assuntos
Anestesiologia , Oclusão com Balão , Parada Cardíaca , Humanos , Cuidados Críticos , Parada Cardíaca/diagnóstico , Parada Cardíaca/etiologia , Parada Cardíaca/prevenção & controle , Ressuscitação
8.
Int J Mol Sci ; 24(2)2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36674722

RESUMO

The 3rd class of BRAF (B-Raf Proto-Oncogene, Serine/Threonine Kinase) variants including G466, D594, and A581 mutations cause kinase death or impaired kinase activity. It is unlikely that RAF (Raf Proto-Oncogene, Serine/Threonine Kinase) inhibitors suppress ERK (Extracellular Signal-Regulated Kinase) signaling in class 3 mutant-driven tumors due to the fact that they preferentially inhibit activated BRAF V600 mutants. However, there are suggestions that class 3 mutations are still associated with enhanced RAS/MAPK (RAS Proto-Oncogene, GTPase/Mitogen-Activated Protein Kinase) activation, potentially due to other mechanisms such as the activation of growth factor signaling or concurrent MAPK pathway mutations, e.g., RAS or NF1 (Neurofibromin 1). A 75-year-old male patient with squamous-cell cancer (SqCC) of the lung and with metastases to the kidney and mediastinal lymph nodes received chemoimmunotherapy (expression of Programmed Cell Death 1 Ligand 1 (PD-L1) on 2% of tumor cells). The chemotherapy was limited due to the accompanying myelodysplastic syndrome (MDS), and pembrolizumab monotherapy was continued for up to seven cycles. At the time of progression, next-generation sequencing was performed and a c.1781A>G (p.Asp594Gly) mutation in the BRAF gene, a c.1381C>T (p.Arg461Ter) mutation in the NF1 gene, and a c.37C>T (p.Gln13Ter) mutation in the FANCC gene were identified. Combined therapy with BRAF (dabrafenib) and MEK (trametinib) inhibitors was used, which resulted in the achievement of partial remission of the primary lesion and lung nodules and the stabilization of metastatic lesions in the kidney and bones. The therapy was discontinued after five months due to myelosuppression associated with MDS. The molecular background was decisive for the patient's fate. NSCLC patients with non-V600 mutations in the BRAF gene rarely respond to anti-BRAF and anti-MEK therapy. The achieved effectiveness of the treatment could be related to a mutation in the NF1 tumor suppressor gene. The loss of NF1 function causes the excessive activation of KRAS and overactivity of the signaling pathway containing BRAF and MEK, which were the targets of the therapy. Moreover, the mutation in the FANCC gene was probably related to MDS development. The NGS technique was crucial for the qualification to treatment and the prediction of the NSCLC course in our patient. The mutations in two genes­the BRAF oncogene and the NF1 tumor suppressor gene­were the reason for the use of dabrafenib and trametinib treatment. The patients achieved short-term disease stabilization. This proved that coexisting mutations in these genes affect the disease course and treatment efficacy.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Carcinoma de Células Escamosas , Neoplasias Pulmonares , Masculino , Humanos , Idoso , Genes da Neurofibromatose 1 , Carcinoma Pulmonar de Células não Pequenas/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Piridonas/farmacologia , Pirimidinonas/farmacologia , Proteínas Serina-Treonina Quinases/genética , Carcinoma de Células Escamosas/genética , MAP Quinases Reguladas por Sinal Extracelular/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Mutação , Serina/genética , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico
9.
Molecules ; 28(11)2023 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-37298856

RESUMO

Despite the increasing availability of modern treatments, including personalized therapies, there is a strong need to search for new drugs that will be effective in the fight against cancer. The chemotherapeutics currently available to oncologists do not always yield satisfactory outcomes when used in systemic treatments, and patients experience burdensome side effects during their application. In the era of personalized therapies, doctors caring for non-small cell lung cancer (NSCLC) patients have been given a powerful weapon, namely molecularly targeted therapies and immunotherapies. They can be used when genetic variants of the disease qualifying for therapy are diagnosed. These therapies have contributed to the extension of the overall survival time in patients. Nevertheless, effective treatment may be hindered in the case of clonal selection of tumor cells with acquired resistance mutations. The state-of-the-art therapy currently used in NSCLC patients is immunotherapy targeting the immune checkpoints. Although it is effective, some patients have been observed to develop resistance to immunotherapy, but its cause is still unknown. Personalized therapies extend the lifespan and time to cancer progression in patients, but only those with a confirmed marker qualifying for the treatment (gene mutations/rearrangements or PD-L1 expression on tumor cells) can benefit from these therapies. They also cause less burdensome side effects than chemotherapy. The article is focused on compounds that can be used in oncology and produce as few side effects as possible. The search for compounds of natural origin, e.g., plants, bacteria, or fungi, exhibiting anticancer properties seems to be a good solution. This article is a literature review of research on compounds of natural origin that can potentially be used as part of NSCLC therapies.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Proteínas Fúngicas/uso terapêutico , Imunoterapia , Bactérias
10.
Curr Issues Mol Biol ; 44(7): 3118-3130, 2022 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-35877439

RESUMO

Clostridium spp. is a large genus of obligate anaerobes and is an extremely heterogeneous group of bacteria that can be classified into 19 clusters. Genetic analyses based on the next-generation sequencing of 16S rRNA genes and metagenome analyses conducted on human feces, mucosal biopsies, and luminal content have shown that the three main groups of strict extremophile anaerobes present in the intestines are Clostridium cluster IV (also known as the Clostridium leptum group), Clostridium cluster XIVa (also known as the Clostridium coccoides group) and Bacteroides. In addition to the mentioned clusters, some C. butyricum strains are also considered beneficial for human health. Moreover, this bacterium has been widely used as a probiotic in Asia (particularly in Japan, Korea, and China). The mentioned commensal Clostridia are involved in the regulation and maintenance of all intestinal functions. In the literature, the development processes of new therapies are described based on commensal Clostridia activity. In addition, some Clostridia are associated with pathogenic processes. Some C. butyricum strains detected in stool samples are involved in botulism cases and have also been implicated in severe diseases such as infant botulism and necrotizing enterocolitis in preterm neonates. The aim of this study is to review reports on the possibility of using Clostridium strains as probiotics, consider their positive impact on human health, and identify the risks associated with the expression of their pathogenic properties.

11.
BMC Cancer ; 22(1): 1001, 2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36131239

RESUMO

BACKGROUND: Despite the fact that tumor microenvironment (TME) and gene mutations are the main determinants of progression of the deadliest cancer in the world - lung cancer, their interrelations are not well understood. Digital pathology data provides a unique insight into the spatial composition of the TME. Various spatial metrics and machine learning approaches were proposed for prediction of either patient survival or gene mutations from this data. Still, these approaches are limited in the scope of analyzed features and in their explainability, and as such fail to transfer to clinical practice. METHODS: Here, we generated 23,199 image patches from 26 hematoxylin-and-eosin (H&E)-stained lung cancer tissue sections and annotated them into 9 different tissue classes. Using this dataset, we trained a deep neural network ARA-CNN. Next, we applied the trained network to segment 467 lung cancer H&E images from The Cancer Genome Atlas (TCGA) database. We used the segmented images to compute human-interpretable features reflecting the heterogeneous composition of the TME, and successfully utilized them to predict patient survival and cancer gene mutations. RESULTS: We achieved per-class AUC ranging from 0.72 to 0.99 for classifying tissue types in lung cancer with ARA-CNN. Machine learning models trained on the proposed human-interpretable features achieved a c-index of 0.723 in the task of survival prediction and AUC up to 73.5% for PDGFRB in the task of mutation classification. CONCLUSIONS: We presented a framework that accurately predicted survival and gene mutations in lung adenocarcinoma patients based on human-interpretable features extracted from H&E slides. Our approach can provide important insights for designing novel cancer treatments, by linking the spatial structure of the TME in lung adenocarcinoma to gene mutations and patient survival. It can also expand our understanding of the effects that the TME has on tumor evolutionary processes. Our approach can be generalized to different cancer types to inform precision medicine strategies.


Assuntos
Adenocarcinoma de Pulmão , Carcinoma Pulmonar de Células não Pequenas , Aprendizado Profundo , Neoplasias Pulmonares , Adenocarcinoma de Pulmão/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Amarelo de Eosina-(YS) , Hematoxilina , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Mutação , Receptor beta de Fator de Crescimento Derivado de Plaquetas , Microambiente Tumoral/genética
12.
Appl Microbiol Biotechnol ; 106(2): 485-495, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34951660

RESUMO

Different serotypes of botulinum toxins (BoNTs) act upon different types of SNARE proteins. This property is used in aesthetic medicine to treat certain eye disorders such as crossed eyes (strabismus) and uncontrolled blinking (blepharospasm), to treat muscle spasms or movement disorders, and, for the two last decades, more and more often, to provide support in cancer therapy, especially so as to obtain analgesic effects upon spastic conditions. The limited literature data also suggests that the addition of BoNTs to the culture of cancer cell lines reduces cell growth, and mitotic activity, and promotes their apoptosis. BoNTs have several advantages that can be emphasized: BoNTs act on both perfusion and oxygenation; moreover, BoNTs are considered to be safe and free of systemic side effects upon administration. Recently, advances in molecular biology techniques have allowed a wide variety of novel BoNT constructs with alternative functions. These constructs could be assessed as potential new classes of anti-cancer drugs. This creates new potential perspectives in the wider use of non-toxic modified BoNT constructs in cancer therapy. In the light of the mentioned premises and existing literature reports, the aim of this review is to summarize current data and reports considering BoNT use in cancer therapy. KEY POINTS : •Botulinum toxin (BoNTs) may be useful in cancer treatment. •Botulinum toxin can serve as an analgesic after cancer radiotherapy. •Botulinum toxin has the ability to inhibit tumor growth and promote apoptosis of neoplastic cells.


Assuntos
Toxinas Botulínicas Tipo A , Toxinas Botulínicas , Neoplasias , Analgésicos , Neoplasias/tratamento farmacológico , Sorogrupo
13.
Nucleic Acids Res ; 48(16): 9387-9405, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32785623

RESUMO

Template-independent terminal ribonucleotide transferases (TENTs) catalyze the addition of nucleotide monophosphates to the 3'-end of RNA molecules regulating their fate. TENTs include poly(U) polymerases (PUPs) with a subgroup of 3' CUCU-tagging enzymes, such as CutA in Aspergillus nidulans. CutA preferentially incorporates cytosines, processively polymerizes only adenosines and does not incorporate or extend guanosines. The basis of this peculiar specificity remains to be established. Here, we describe crystal structures of the catalytic core of CutA in complex with an incoming non-hydrolyzable CTP analog and an RNA with three adenosines, along with biochemical characterization of the enzyme. The binding of GTP or a primer with terminal guanosine is predicted to induce clashes between 2-NH2 of the guanine and protein, which would explain why CutA is unable to use these ligands as substrates. Processive adenosine polymerization likely results from the preferential binding of a primer ending with at least two adenosines. Intriguingly, we found that the affinities of CutA for the CTP and UTP are very similar and the structures did not reveal any apparent elements for specific NTP binding. Thus, the properties of CutA likely result from an interplay between several factors, which may include a conformational dynamic process of NTP recognition.


Assuntos
Proteínas de Bactérias/genética , Citosina/metabolismo , RNA Nucleotidiltransferases/genética , RNA/genética , Aspergillus nidulans/genética , Proteínas de Bactérias/química , Sítios de Ligação/genética , Cristalografia por Raios X , Citosina/química , Modelos Moleculares , Poli A/química , Poli A/genética , RNA Nucleotidiltransferases/química , Especificidade por Substrato
14.
Int J Mol Sci ; 23(4)2022 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-35216378

RESUMO

Despite the enormous progress and development of modern therapies, lung cancer remains one of the most common causes of death among men and women. The key element in the development of new anti-cancer drugs is proper planning of the preclinical research phase. The most adequate basic research exemplary for cancer study are 3D tumor microenvironment in vitro models, which allow us to avoid the use of animal models and ensure replicable culture condition. However, the question tormenting the scientist is how to choose the best tool for tumor microenvironment research, especially for extremely heterogenous lung cancer cases. In the presented review we are focused to explain the key factors of lung cancer biology, its microenvironment, and clinical gaps related to different therapies. The review summarized the most important strategies for in vitro culture models mimicking the tumor-tumor microenvironmental interaction, as well as all advantages and disadvantages were depicted. This knowledge could facilitate the right decision to designate proper pre-clinical in vitro study, based on available analytical tools and technical capabilities, to obtain more reliable and personalized results for faster introduction them into the future clinical trials.


Assuntos
Neoplasias Pulmonares/patologia , Esferoides Celulares/patologia , Microambiente Tumoral/fisiologia , Animais , Técnicas de Cultura de Células/métodos , Humanos , Organoides/patologia
15.
Int J Mol Sci ; 23(6)2022 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-35328510

RESUMO

Currently, one of the leading treatments for non-small-cell lung cancer is immunotherapy involving immune checkpoint inhibitors. These monoclonal antibodies restore the anti-tumour immune response altered by negative immune checkpoint interactions. The most commonly used immunotherapeutics in monotherapy are anti-PD-1 and anti-PD-L1 antibodies. The effectiveness of both groups of antibodies has been proven in many clinical trials, which have translated into positive immunotherapeutic registrations for cancer patients worldwide. These antibodies are generally well tolerated, and certain patients achieve durable responses. However, given the resistance of some patients to this form of therapy, along with its other drawbacks, such as adverse events, alternatives are constantly being sought. Specifically, new drugs targeting already known molecules are being tested, and new potential targets are being explored. The aim of this paper is to provide an overview of the latest developments in this area.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Anticorpos Monoclonais/uso terapêutico , Antígeno B7-H1 , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Humanos , Fatores Imunológicos/uso terapêutico , Imunoterapia/efeitos adversos , Neoplasias Pulmonares/tratamento farmacológico , Receptor de Morte Celular Programada 1
16.
Molecules ; 27(9)2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35566166

RESUMO

The Chelidonium majus plant is rich in biologically active isoquinoline alkaloids. These alkaline polar compounds are isolated from raw materials with the use of acidified water or methanol; next, after alkalisation of the extract, they are extracted using chloroform or dichloromethane. This procedure requires the use of toxic solvents. The present study assessed the possibility of using volatile natural deep eutectic solvents (VNADESs) for the efficient and environmentally friendly extraction of Chelidonium alkaloids. The roots and herb of the plant were subjected three times to extraction with various menthol, thymol, and camphor mixtures and with water and methanol (acidified and nonacidified). It has been shown that alkaloids can be efficiently isolated using menthol-camphor and menthol-thymol mixtures. In comparison with the extraction with acidified methanol, the use of appropriate VNADESs formulations yielded higher amounts of protopine (by 16%), chelidonine (35%), berberine (76%), chelerythrine (12%), and coptisine (180%). Sanguinarine extraction efficiency was at the same level. Additionally, the values of the contact angles of the raw materials treated with the tested solvents were assessed, and higher wetting dynamics were observed in the case of VNADESs when compared with water. These results suggest that VNADESs can be used for the efficient and environmentally friendly extraction of Chelidonium alkaloids.


Assuntos
Alcaloides , Chelidonium , Cânfora , Solventes Eutéticos Profundos , Isoquinolinas , Mentol , Metanol , Extratos Vegetais , Solventes , Timol , Água
17.
Folia Med Cracov ; 62(4): 25-33, 2022 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-36854084

RESUMO

Oncological surgery is the primary treatment for gynecological malignancies and is inseparably linked with anesthesia. The modern approach to interdisciplinary and multidisciplinary perioperative care in gynecologic oncological patients improves the outcome. This paper presents a review of perioperative management of patients with gynecologic oncology related to enhanced recovery after surgery and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy. We performed a literature search on MEDLINE, EMBASE, Google Scholar, the Cochrane Central Register of Controlled Trials, and Clinical Trials. The database search focused on selected topics related to perioperative gynecological oncology care. The authors also contributed through individual, independent literature searches.


Assuntos
Neoplasias dos Genitais Femininos , Assistência Perioperatória , Feminino , Humanos , Neoplasias dos Genitais Femininos/cirurgia , Recuperação Pós-Cirúrgica Melhorada , Procedimentos Cirúrgicos de Citorredução
18.
Folia Med Cracov ; 62(3): 19-42, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36309829

RESUMO

Malignant neoplasms are currently a severe medical challenge and the second leading cause of death worldwide. The modern anesthesia applied may improve the patient outcome. This paper presents a review of anesthesia management related to patients with gynaecologic malignancies. It includes the influence of the type of anesthesia on cancer recurrence, application of regional anesthesia in gynaecologic oncologic surgery, and selected aspects of anesthesia for robotic surgery. We performed a literature search on MEDLINE, EMBASE, Google Scholar, the Cochrane Central Register of Controlled Trials, and Clinical Trials. The database search focused on the topics related to anesthesia in gynecological oncology. The authors also contributed through individual, independent literature searches.


Assuntos
Anestesia , Neoplasias , Humanos
19.
Crit Rev Eukaryot Gene Expr ; 31(6): 55-68, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34936292

RESUMO

Genome analyses using next-generation sequencing are providing more and more information on DNA sequences. However, there is a trend towards the return to RNA sequencing analyses, including both mRNAs and RNAs as simultaneous regulatory molecules. Consequently, enhancer RNA (eRNA) molecules are now extensively studied. The existence of eRNAs has been known for some time, but their roles are not yet fully understood. It turns out that the sequences of super-enhancers (hyperactive enhancers) have a significant and stimulating effect on the expression of oncogenes. Enhancers act at the level of transcription initiation and interact with many transcription factors that bind to DNA. Therapies targeting molecules that regulate gene expression may be effective cancer treatments, independent of tumor type, but relying on transcription factors and super-enhancers universally overexpressed in various types of cancer. This kind of treatment could become a new tissue-agnostic anticancer therapy.


Assuntos
Elementos Facilitadores Genéticos , Transcriptoma , Genômica , Humanos , RNA/genética , Transcrição Gênica , Transcriptoma/genética
20.
Appl Microbiol Biotechnol ; 105(4): 1395-1405, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33492450

RESUMO

Currently, increasing attention cancer treatment has focused on molecularly targeted therapies and more recently on immunotherapies targeting immune checkpoints. However, even such advanced treatment may be ineffective. The reasons for this are sought, inter alia, in the human microbiome. In our intestines, there are bacteria that are beneficial to us, but pathogenic microorganisms may also be present. Microbial imbalance (dysbiosis) is now perceived as one of the gateways to cancer. However, it is feasible to use bacteria and their metabolites to restore the natural, beneficial microbiome during oncological treatment. Akkermansia mucinifila, Enterococcus hirae, or Faecalibacterium prausnitzii are bacteria that exhibit this beneficial potential. Greater benefits of therapy can be observed in cancer patients enriched in these bacterial species and treated with anti-PD-1, anti-PD-L1, or anti-CTLA-4 monoclonal antibodies. In this review, we present issues related to the role of bacteria in carcinogenesis and their therapeutic potential "supporting" modern anti-cancer therapies.Key Points• Bacteria can be directly or indirectly a cancer trigger.• Bacterial metabolites regulate the pathways associated with carcinogenesis.• Intestinal bacteria activate the immune system to fight cancer.


Assuntos
Microbioma Gastrointestinal , Microbiota , Neoplasias , Disbiose , Faecalibacterium prausnitzii , Humanos , Neoplasias/tratamento farmacológico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA