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1.
Int J Cancer ; 154(6): 1097-1110, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38095490

RESUMO

Gastrointestinal bacteria are known to have an impact on local and systemic immunity, and consequently either promote or suppress cancer development. Following the notion that perinatal bacterial exposure might confer immune system competency for life, we investigated whether early-life administration of cholera-toxin (CT), a protein exotoxin of the small intestine pathogenic bacterium Vibrio cholerae, may shape local and systemic immunity to impart a protective effect against tumor development in epithelia distantly located from the gut. For that, newborn mice were orally treated with low non-pathogenic doses of CT and later challenged with the carcinogen 7,12-dimethylbenzanthracene (DMBA), known to cause mainly mammary, but also skin, lung and stomach cancer. Our results revealed that CT suppressed the overall incidence and multiplicity of tumors, with varying efficiencies among cancer types, and promoted survival. Harvesting mouse tissues at an earlier time-point (105 instead of 294 days), showed that CT does not prevent preneoplastic lesions per se but it rather hinders their evolution into tumors. CT pretreatment universally increased apoptosis in the cancer-prone mammary, lung and nonglandular stomach, and altered the expression of several cancer-related molecules. Moreover, CT had a long-term effect on immune system cells and factors, the most prominent being the systemic neutrophil decrease. Finally, CT treatment significantly affected gut bacterial flora composition, leading among others to a major shift from Clostridia to Bacilli class abundance. Overall, these results support the notion that early-life CT consumption is able to affect host's immune, microbiome and gene expression profiles toward the prevention of cancer.


Assuntos
Neoplasias , Vibrio cholerae , Animais , Camundongos , Toxina da Cólera , Desmame , Carcinogênese/induzido quimicamente
2.
Molecules ; 24(14)2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31323754

RESUMO

Origanum species are plants rich in volatile oils that are mainly used for culinary purposes. In recent years, there has been a growing interest in the biological activities of their essential oils. Origanum onites L. is a plant mainly found in Greece, Turkey, and Sicily, whose oil is rich in carvacrol, a highly bioactive phytochemical. The aim of this study was to analyze the chemical composition of Origanum onites essential oil (OOEO), and investigate its potential anticancer effects in vitro and in vivo. GC/MS analysis identified carvacrol as OOEO's main constituent. In vitro antiproliferative activity was assayed with the sulforhodamine B (SRB) assay against human cancer cell lines from four tumor types. HT-29, a colorectal cancer cell line, was the most sensitive to the antiproliferative activity of OOEO. Wound-healing assay and Annexin V-PI staining were employed to investigate the antimigratory and the pro-apoptotic potential of OOEO, respectively, against human (HT-29) and murine (CT26) colon cancer cells. Notably, OOEO attenuated migration and induced apoptosis-related morphological changes in both cell lines. Prophylactic oral administration of the oil in a BALB/c experimental mouse model inhibited the growth of syngeneic CT26 colon tumors. As far as we know, this is the first report on the antitumor potential of orally administered OOEO.


Assuntos
Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Origanum/química , Animais , Antineoplásicos Fitogênicos/isolamento & purificação , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Fracionamento Químico , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Camundongos , Óleos Voláteis/isolamento & purificação , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
3.
Artigo em Inglês | MEDLINE | ID: mdl-29866877

RESUMO

Micafungin (MFG) demonstrates potent activity against biofilms of Candida albicans and Candida parapsilosis, the most frequent opportunistic fungal pathogens. Little is known about its immunopharmacologic effect on antibiofilm activity of phagocytic cells following exposure to Candida biofilms. In this study, we investigated the effects of MFG on human neutrophil-mediated damage of C. albicans and C. parapsilosis biofilms by XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] and the potential mechanisms underlying the immunomodulatory MFG activities on cultured monocyte-derived THP-1 cells in response to these biofilms by reverse transcription-PCR and sandwich and multiplex enzyme-linked immunosorbent assay. Preexposure of C. albicans to subinhibitory MFG concentrations significantly enhanced neutrophil-mediated biofilm damage, an effect that appears to be species specific since a comparable effect was not observed with drug-pretreated C. parapsilosis biofilms. Human THP-1 cells responded to both Candida biofilms through Toll-like receptor 2 (TLR2) and TLR4 upregulation, modest TLR6 involvement, and enhanced NLRP3 activation, whereas the signal was relayed to the nucleus via NF-κB p65 activation. MFG caused 2- to 3-fold lower TLR2 and TLR4 mRNA levels than those caused by either organism. C. albicans biofilms induced a robust proinflammatory response, whereas C. parapsilosis biofilms either alone or in the presence of MFG caused increased interleukin-1ß (IL-1ß) production, but small amounts of IL-8, IL-23, and tumor necrosis factor alpha. In conclusion, MFG may condition THP-1 cells toward an inflammatory response through TLR2/TLR4 recruitment. Inflammatory signals observed with C. albicans biofilms are considerably reduced upon exposure of THP-1 cells to C. parapsilosis biofilms, possibly enhancing fungal survival and increasing biofilm pathogenicity.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Candida parapsilosis/efeitos dos fármacos , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Micafungina/farmacologia , Neutrófilos/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida albicans/crescimento & desenvolvimento , Candida albicans/imunologia , Candida parapsilosis/crescimento & desenvolvimento , Candida parapsilosis/imunologia , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Regulação da Expressão Gênica/efeitos dos fármacos , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Interleucina-23/genética , Interleucina-23/imunologia , Interleucina-8/genética , Interleucina-8/imunologia , Testes de Sensibilidade Microbiana , Neutrófilos/imunologia , Neutrófilos/microbiologia , Transdução de Sinais , Células THP-1 , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/imunologia , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/imunologia
4.
Molecules ; 23(1)2018 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-29329229

RESUMO

The aim of the study was to characterize the chemical composition and biological properties of the essential oil from the plant Lippia citriodora grown in Greece. The essential oil volatiles were analyzed by gas chromatography-mass spectrometry GC-MS indicating citral as the major component. Τhe antimicrobial properties were assayed using the disk diffusion method and the minimum inhibitory and non-inhibitory concentration values were determined. Listeria monocytogenes, Staphylococcus epidermidis, Staphylococcus aureus, Saccharomyces cerevisiae, and Aspergillus niger were sensitive to Lippia citriodora oil, but not Escherichia coli, Salmonella Enteritidis, Salmonella typhimurium, and Pseudomonas fragi. Adversely, all microbes tested were sensitive to citral. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays were used to assess direct antioxidant activity, which proved to be weak for both agents, while comet assay was utilized to study the cytoprotective effects against H2O2-induced oxidative damage in Jurkat cells. Interestingly, the oil showed a more profound cytoprotective effect compared to citral. The antiproliferative activity was evaluated in a panel of cancer cell lines using the sulforhodamine B (SRB) and 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-S-(phenylamino) carbonyl-2-tetrazolium hydroxide (XTT) assays and both agents demonstrated potent antiproliferative activity with citral being more cytotoxic than the oil. Taken together, the essential oil of Lippia citriodora and its major component, citral, exert diverse biological properties worthy of further investigation.


Assuntos
Lippia/química , Óleos Voláteis/química , Compostos Fitoquímicos/química , Óleos de Plantas/química , Antibacterianos/química , Antibacterianos/farmacologia , Antifúngicos/química , Antifúngicos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Óleos Voláteis/farmacologia , Compostos Fitoquímicos/farmacologia , Óleos de Plantas/análise , Óleos de Plantas/farmacologia
5.
Molecules ; 22(1)2016 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-28042859

RESUMO

Silibinin, extracted from milk thistle (Silybum marianum L.), has exhibited considerable preclinical activity against prostate carcinoma. Its antitumor and chemopreventive activities have been associated with diverse effects on cell cycle, apoptosis, and receptor-dependent mitogenic signaling pathways. Here we hypothesized that silibinin's pleiotropic effects may reflect its interference with epigenetic mechanisms in human prostate cancer cells. More specifically, we have demonstrated that silibinin reduces gene expression levels of the Polycomb Repressive Complex 2 (PRC2) members Enhancer of Zeste Homolog 2 (EZH2), Suppressor of Zeste Homolog 12 (SUZ12), and Embryonic Ectoderm Development (EED) in DU145 and PC3 human prostate cancer cells, as evidenced by Real Time Polymerase Chain Reaction (RT-PCR). Furthermore immunoblot and immunofluorescence analysis revealed that silibinin-mediated reduction of EZH2 levels was accompanied by an increase in trimethylation of histone H3 on lysine (Κ)-27 residue (H3K27me3) levels and that such response was, in part, dependent on decreased expression levels of phosphorylated Akt (ser473) (pAkt) and phosphorylated EZH2 (ser21) (pEZH2). Additionally silibinin exerted other epigenetic effects involving an increase in total DNA methyltransferase (DNMT) activity while it decreased histone deacetylases 1-2 (HDACs1-2) expression levels. We conclude that silibinin induces epigenetic alterations in human prostate cancer cells, suggesting that subsequent disruptions of central processes in chromatin conformation may account for some of its diverse anticancer effects.


Assuntos
Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Proteína Potenciadora do Homólogo 2 de Zeste/biossíntese , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Complexo Repressor Polycomb 2/biossíntese , Neoplasias da Próstata/tratamento farmacológico , Silimarina/farmacologia , Linhagem Celular Tumoral , DNA (Citosina-5-)-Metiltransferases , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Epigênese Genética , Histona Desacetilase 1/biossíntese , Histona Desacetilase 2/biossíntese , Histonas/metabolismo , Humanos , Masculino , Metilação/efeitos dos fármacos , Proteínas de Neoplasias , Fosforilação/efeitos dos fármacos , Complexo Repressor Polycomb 2/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Silibina , Fatores de Transcrição
6.
Molecules ; 21(8)2016 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-27537869

RESUMO

Natural products, known for their medicinal properties since antiquity, are continuously being studied for their biological properties. In the present study, we analyzed the composition of the volatile preparations of essential oils of the Greek plants Ocimum basilicum (sweet basil), Mentha spicata (spearmint), Pimpinella anisum (anise) and Fortunella margarita (kumquat). GC/MS analyses revealed that the major components in the essential oil fractions, were carvone (85.4%) in spearmint, methyl chavicol (74.9%) in sweet basil, trans-anethole (88.1%) in anise, and limonene (93.8%) in kumquat. We further explored their biological potential by studying their antimicrobial, antioxidant and antiproliferative activities. Only the essential oils from spearmint and sweet basil demonstrated cytotoxicity against common foodborne bacteria, while all preparations were active against the fungi Saccharomyces cerevisiae and Aspergillus niger. Antioxidant evaluation by DPPH and ABTS radical scavenging activity assays revealed a variable degree of antioxidant potency. Finally, their antiproliferative potential was tested against a panel of human cancer cell lines and evaluated by using the sulforhodamine B (SRB) assay. All essential oil preparations exhibited a variable degree of antiproliferative activity, depending on the cancer model used, with the most potent one being sweet basil against an in vitro model of human colon carcinoma.


Assuntos
Mentha spicata/química , Ocimum basilicum/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Pimpinella/química , Rutaceae/química , Derivados de Alilbenzenos , Anisóis/isolamento & purificação , Anisóis/farmacologia , Aspergillus niger/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Monoterpenos Cicloexânicos , Cicloexenos/isolamento & purificação , Cicloexenos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Microbiologia de Alimentos , Humanos , Limoneno , Testes de Sensibilidade Microbiana , Monoterpenos/isolamento & purificação , Monoterpenos/farmacologia , Oxirredução/efeitos dos fármacos , Óleos de Plantas/química , Óleos de Plantas/farmacologia , Saccharomyces cerevisiae/efeitos dos fármacos , Terpenos/isolamento & purificação , Terpenos/farmacologia
7.
Mol Med ; 19: 115-23, 2013 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-23615967

RESUMO

Critical processes of B-cell physiology, including immune signaling through the B-cell receptor (BcR) and/or Toll-like receptors (TLRs), are targeted by microRNAs. With this in mind and also given the important role of BcR and TLR signaling and microRNAs in chronic lymphocytic leukemia (CLL), we investigated whether microRNAs could be implicated in shaping the behavior of CLL clones with distinct BcR and TLR molecular and functional profiles. To this end, we examined 79 CLL cases for the expression of 33 microRNAs, selected on the following criteria: (a) deregulated in CLL versus normal B-cells; (b) differentially expressed in CLL subgroups with distinct clinicobiological features; and, (c) if meeting (a) + (b), having predicted targets in the immune signaling pathways. Significant upregulation of miR-150, miR-29c, miR-143 and miR-223 and downregulation of miR-15a was found in mutated versus unmutated CLL, with miR-15a showing the highest fold difference. Comparison of two major subsets with distinct stereotyped BcRs and signaling signatures, namely subset 1 [IGHV1/5/7-IGKV1(D)-39, unmutated, bad prognosis] versus subset 4 [IGHV4-34/IGKV2-30, mutated, good prognosis] revealed differences in the expression of miR-150, miR-29b, miR-29c and miR-101, all down-regulated in subset 1. We were also able to link these distinct microRNA profiles with cellular phenotypes, importantly showing that, in subset 1, miR-101 downregulation is associated with overexpression of the enhancer of zeste homolog 2 (EZH2) protein, which has been associated with clinical aggressiveness in other B-cell lymphomas. In conclusion, specific miRNAs differentially expressed among CLL subgroups with distinct BcR and/or TLR signaling may modulate the biological and clinical behavior of the CLL clones.


Assuntos
Leucemia Linfocítica Crônica de Células B/genética , MicroRNAs/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste , Feminino , Humanos , Fenômenos Imunogenéticos , Imunoglobulinas/imunologia , Leucemia Linfocítica Crônica de Células B/imunologia , Masculino , Complexo Repressor Polycomb 2/genética , RNA Mensageiro/metabolismo , Receptores de Antígenos de Linfócitos B/imunologia
8.
J Allergy Clin Immunol ; 130(1): 233-40.e5, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22664159

RESUMO

BACKGROUND: The interplay between allergy and autoimmunity has been a matter of long debate. Epidemiologic studies point to a decreased frequency of allergy in patients with autoimmune diseases. However, recent studies suggest that IL-17 and related cytokines, which play a central role in autoimmunity, might also promote allergy. OBJECTIVE: To address this controversy, we systematically studied the interactions between T(H)17-related cytokines and the thymic stromal lymphopoietin (TSLP)-mediated proallergic pathway. METHODS: We used human primary dendritic cells (DCs), T cells, and skin explants. A novel geometric representation and multivariate ANOVA were used to analyze the T(H) cytokine profile. RESULTS: We show that IL-17A specifically inhibits TSLP production but increases proinflammatory IL-8 production in human skin explants exposed to TNF-α and IL-4. This inhibitory activity was confirmed in cultured skin explants of atopic dermatitis lesions. At the T-cell level, T(H)17-polarizing cytokines (IL-1ß, IL-6, TGF-ß, and IL-23) inhibited T(H)2 differentiation induced by TSLP-activated DCs. This led to a global dominance of a T(H)17-polarizing environment over TSLP-activated DCs, as revealed by clustering and computational analysis. CONCLUSIONS: Our data indicate that T(H)17-related cytokines are negative regulators of the TSLP immune pathway. This might explain the decreased frequency of allergy in patients with autoimmunity and suggests new means of manipulating proallergic responses.


Assuntos
Citocinas/antagonistas & inibidores , Interleucina-17/farmacologia , Células Th17/imunologia , Células Th2/metabolismo , Autoimunidade , Diferenciação Celular , Células Cultivadas , Citocinas/biossíntese , Citocinas/imunologia , Citocinas/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Dermatite Atópica/imunologia , Dermatite Atópica/metabolismo , Dermatite Atópica/fisiopatologia , Humanos , Interleucina-17/metabolismo , Pele/imunologia , Pele/metabolismo , Pele/fisiopatologia , Células Th17/metabolismo , Células Th2/citologia , Células Th2/efeitos dos fármacos , Células Th2/imunologia , Linfopoietina do Estroma do Timo
9.
Probiotics Antimicrob Proteins ; 15(3): 524-534, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-34676502

RESUMO

The intestinal microbiota has been identified as a crucial regulator of the overall health, with studies describing its influence in a variety of disorders and developmental processes throughout the body. A widely accepted approach of influencing the microbiota and regulating its functionality in health or disease is the consumption of probiotics. In this study, we aimed to identify the impact of probiotic Lacticaseibacillus casei ATCC393 on the intestinal microbiota of mice and circulating soluble products of microbial origin or the immune system. Investigation of the gut microflora using next-generation sequencing analysis revealed alterations in the microbial populations following consumption of the probiotic. Abundance of taxa classified as Muribaculaceae was increased in lactobacilli-fed animals, while abundance of taxa classified as Lachnospiraceae and Oscillospiraceae was decreased. In addition, the composition of the intestinal microbiota was modified by the administration of L. casei, as evident by the clustering of test subjects when inspecting beta diversity, without however any significant effect on the alpha diversity of the animals. Finally, production of IgA in the intestinal lumen of mice that had received the microorganism was significantly increased, as was the concentration of lactic acid, while levels of acetic acid were noticeably lower in the L. casei group. The findings suggest that L. casei can be considered a potential candidate strain for the modulation of intestinal homeostasis and a component of dietary interventions aiming to improve overall health.


Assuntos
Lacticaseibacillus casei , Microbiota , Probióticos , Animais , Lacticaseibacillus , Imunoglobulina A , Administração Oral
10.
Front Oncol ; 13: 1123029, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36845709

RESUMO

The analysis of the immunogenetic background of multiple myeloma (MM) has proven key to understanding disease ontogeny. However, limited information is available regarding the immunoglobulin (IG) gene repertoire in MM cases carrying different heavy chain isotypes. Here, we studied the IG gene repertoire in a series of 523 MM patients, of whom 165 and 358 belonged to the IgA and IgG MM groups, respectively. IGHV3 subgroup genes predominated in both groups. However, at the individual gene level, significant (p<0.05) differences were identified regarding IGHV3-21 (frequent in IgG MM) and IGHV5-51 (frequent in IgA MM). Moreover, biased pairings were identified between certain IGHV genes and IGHD genes in IgA versus IgG MM. Turning to the imprints of somatic hypermutation (SHM), the bulk of rearrangements (IgA: 90.9%, IgG: 87.4%) were heavily mutated [exhibiting an IGHV germline identity (GI) <95%]. SHM topology analysis disclosed distinct patterns in IgA MM versus IgG MM cases expressing B cell receptor IG encoded by the same IGHV gene: the most pronounced examples concerned the IGHV3-23, IGHV3-30 and IGHV3-9 genes. Furthermore, differential SHM targeting was also identified between IgA MM versus IgG MM, particularly in cases utilizing certain IGHV genes, alluding to functional selection. Altogether, our detailed immunogenetic evaluation in the largest to-date series of IgA and IgG MM patients reveals certain distinct features in the IGH gene repertoires and SHM. These findings suggest distinct immune trajectories for IgA versus IgG MM, further underlining the role of external drive in the natural history of MM.

11.
Biomed Pharmacother ; 149: 112755, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35276466

RESUMO

Lactobacilli have been shown to inhibit or suppress cancer cell growth through the release of strain-specific bioactive metabolites and their inclusion in functional foods could exert a health promoting activity on human health. Herein, we examined the antiproliferative activity of the Lactiplantibacillus plantarum strains S2T10D and O2T60C, which have been previously shown to exert different butyrogenic activities. Human HT-29 cells were employed as an in vitro colon cancer model and both bacterial strains were found to inhibit their growth. However, the strain S2T10D showed a greater antiproliferative activity which, interestingly, was correlated to its butyrogenic capability. Noteworthy, for the non-butyrogenic strain O2T60C, the growth inhibitory capability was rather limited. Furthermore, both the butyrate-containing supernatant of S2T10D and glucose-deprived cell culture medium supplemented with the same concentration of butyrate found in S2T10D supernatant, induced a pH-independent cancer cell growth inhibition accompanied by downregulation of cyclin D1 at mRNA level. The downregulation of cyclin D1 gene expression was accompanied by cell cycle arrest in G2/M phase and decrease of cyclin B1 and D1 protein levels. This in vitro study underlines the impact of Lpb. plantarum in the growth inhibition of cancer cells, and proposes butyrate-mediated cell cycle regulation as a potential involved mechanism. Since the production of butyric acid in Lpb. plantarum has been proven strain-dependent and differentially boosted by specific prebiotic compounds, our results open future research paths to determine whether this metabolic activity could be modulated in vivo by enhancing this antiproliferative effects on cancer cells.


Assuntos
Neoplasias do Colo , Ciclina D1 , Ácido Butírico , Proliferação de Células , Ciclina D1/metabolismo , Humanos , Lactobacillaceae/metabolismo
12.
Viruses ; 14(4)2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-35458441

RESUMO

In order to gain a deeper understanding of the recently emerged and highly divergent Omicron variant of concern (VoC), a study of amino acid substitution (AAS) patterns was performed and compared with those of the other four successful variants of concern (Alpha, Beta, Gamma, Delta) and one closely related variant of interest (VoI-Lambda). The Spike ORF consistently emerges as an AAS hotspot in all six lineages, but in Omicron this enrichment is significantly higher. The progenitors of each of these VoC/VoI lineages underwent positive selection in the Spike ORF. However, once they were established, their Spike ORFs have been undergoing purifying selection, despite the application of global vaccination schemes from 2021 onwards. Our analyses reject the hypothesis that the heavily mutated receptor binding domain (RBD) of the Omicron Spike was introduced via recombination from another closely related Sarbecovirus. Thus, successive point mutations appear as the most parsimonious scenario. Intriguingly, in each of the six lineages, we observed a significant number of AAS wherein the new residue is not present at any homologous site among the other known Sarbecoviruses. Such AAS should be further investigated as potential adaptations to the human host. By studying the phylogenetic distribution of AAS shared between the six lineages, we observed that the Omicron (BA.1) lineage had the highest number (8/10) of recurrent mutations.


Assuntos
COVID-19 , SARS-CoV-2 , Substituição de Aminoácidos , Humanos , Filogenia , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/metabolismo
13.
Viruses ; 14(1)2022 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-35062282

RESUMO

Coronaviruses (CoVs) constitute a large and diverse subfamily of positive-sense single-stranded RNA viruses. They are found in many mammals and birds and have great importance for the health of humans and farm animals. The current SARS-CoV-2 pandemic, as well as many previous epidemics in humans that were of zoonotic origin, highlights the importance of studying the evolution of the entire CoV subfamily in order to understand how novel strains emerge and which molecular processes affect their adaptation, transmissibility, host/tissue tropism, and patho non-homologous genicity. In this review, we focus on studies over the last two years that reveal the impact of point mutations, insertions/deletions, and intratypic/intertypic homologous and non-homologous recombination events on the evolution of CoVs. We discuss whether the next generations of CoV vaccines should be directed against other CoV proteins in addition to or instead of spike. Based on the observed patterns of molecular evolution for the entire subfamily, we discuss five scenarios for the future evolutionary path of SARS-CoV-2 and the COVID-19 pandemic. Finally, within this evolutionary context, we discuss the recently emerged Omicron (B.1.1.529) VoC.


Assuntos
COVID-19/epidemiologia , COVID-19/virologia , Evolução Molecular , SARS-CoV-2/genética , Animais , Antivirais/farmacologia , COVID-19/prevenção & controle , Coronavirus/classificação , Coronavirus/genética , Coronavirus/imunologia , Desenho de Fármacos , Genoma Viral/genética , Humanos , Mutação , Recombinação Genética , SARS-CoV-2/classificação , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/imunologia , Vacinação , Vacinas Virais/imunologia , Tratamento Farmacológico da COVID-19
14.
Cancers (Basel) ; 13(21)2021 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-34771499

RESUMO

Colorectal cancer is a health problem with high mortality rates and prevalence. Thus, innovative treatment approaches need to be developed. Biogenic nanoparticles are nanomaterials that can be synthesised in biological systems and, compared to chemically synthesised nanoparticles, have better bioavailability while being more cost-effective, eco-friendlier, and less toxic. In our previous studies, the probiotic strain Lactobacillus casei ATCC 393 was used to synthesise selenium nanoparticles (SeNps), which were shown to inhibit colon cancer cell growth in vitro and in vivo. Herein, we have further investigated SeNps' pro-apoptotic activity and their ability to induce immunogenic cell death (ICD) in colon cancer cells. The SeNps' effect on Caco-2 cells growth was examined along with their potential to induce caspase activation. Moreover, the expression of typical pro-apoptotic and ICD markers were examined in SeNps-treated HT29 and CT26 cells by flow cytometry, Western blot, ELISA and fluorescence microscopy. Elevated caspase-3 activation and surface phosphatyldoserine, that subsided upon co-incubation with a pan-caspase inhibitor, were detected in SeNps-treated cells. Furthermore, nanoparticles induced modulation of the expression of various apoptosis-related proteins. We also report the detection of biomarkers involved in ICD, namely the translocation of calreticulin and ERp57, the release of HMGB1 and ATP, and the secretion of pro-inflammatory cytokines from SeNps-treated cells. Moreover, RAW246.7 macrophages exhibited a higher rate of phagocytosis against treated CT26 when compared to control cells. Taken together, our findings indicate that treatment with SeNps might be an efficient strategy to destroy tumour cells by inducing apoptotic cell death and triggering immune responses.

15.
Nanoscale Adv ; 3(9): 2516-2528, 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-36134160

RESUMO

Selenium compounds exhibit excellent anticancer properties but have a narrow therapeutic window. Selenium nanoparticles, however, are less toxic compared to other selenium forms, and their biogenic production leads to improved bioavailability. Herein, we used the probiotic strain Lactobacillus casei ATCC 393, previously shown to inhibit colon cancer cell growth, to synthesize biogenic selenium nanoparticles. We examined the anticancer activity of orally administered L. casei, L. casei-derived selenium nanoparticles and selenium nanoparticle-enriched L. casei, and investigated their antitumor potential in the CT26 syngeneic colorectal cancer model in BALB/c mice. Our results indicate that L. casei-derived selenium nanoparticles and selenium nanoparticle-enriched L. casei exert cancer-specific antiproliferative activity in vitro. Moreover, the nanoparticles were found to induce apoptosis and elevate reactive oxygen species levels in cancer cells. It is noteworthy that, when administered orally, selenium nanoparticle-enriched L. casei attenuated the growth of colon carcinoma in mice more effectively than the isolated nanoparticles or L. casei, suggesting a potential additive effect of the nanoparticles and the probiotic. To the best of our knowledge this is the first comparative study examining the anticancer effects of selenium nanoparticles synthesized by a microorganism, the selenium nanoparticle-enriched microorganism and the sole microorganism.

16.
Antioxidants (Basel) ; 10(1)2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33477450

RESUMO

The antioxidant, cytoprotective, and wound-healing potential of the essential oil from the resin of Pistacia lentiscus var. chia (mastic oil) was evaluated, along with that of its major components, myrcene and α-pinene. Antioxidant potential was monitored as: (i) direct antioxidant activity as assessed by 2,2-di-phenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and ABTS assays; (ii) DNA damage protection activity; and (iii) cytoprotective activity as assessed via induction of transcription of genes related to the antioxidant response in human keratinocyte cells (HaCaT). The cytoprotective potential of the test substances was further evaluated against ultraviolet radiation B (UVB)- or H2O2-induced oxidative damage, whereas their regenerative capability was accessed by monitoring the wound closure rate in HaCaT. Μastic oil and major components did not show significant direct antioxidant activity, however they increased the mRNA levels of antioxidant response genes, suggesting indirect antioxidant activity. Treatment of HaCaT with the test substances before and after UVB irradiation resulted in increased cell viability in the cases of pre-treatment with mastic oil or post-treatment with myrcene. Increased cytoprotection was also observed in the case of cell treatment with mastic oil or its major components prior to H2O2 exposure. Finally, mastic oil and myrcene demonstrated a favorable dose-dependent effect for cell migration and wound closure. Collectively, mastic essential oil may exert its promising cytoprotective properties through indirect antioxidant mechanisms.

17.
Antioxidants (Basel) ; 10(6)2021 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-34070804

RESUMO

Lippia citriodora is a flowering plant cultivated for its lemon-scented leaves and used in folk medicine for the preparation of tea for the alleviation of symptoms of gastrointestinal disorders, cold, and asthma. The oil extracted from the plant leaves was shown to possess antioxidant potential and to exert antiproliferative activity against breast cancer. The aim of this study was to further investigate potential antitumor effects of L. citriodora oil (LCO) on breast cancer. The in vitro antiproliferative activity of LCO was examined against murine DA3 breast cancer cells by the sulforhodamine B assay. We further explored the LCO's pro-apoptotic potential with the Annexin-PI method. The LCO's anti-migratory effect was assessed by the wound-healing assay. LCO was found to inhibit the growth of DA3 cells in vitro, attenuate their migration, and induce apoptosis. Finally, oral administration of LCO for 14 days in mice inhibited by 55% the size of developing tumors in the DA3 murine tumor model. Noteworthy, in the tumor tissue of LCO-treated mice the apoptotic marker cleaved caspase-3 was elevated, while a reduced protein expression of survivin was observed. These results indicate that LCO, as a source of bioactive compounds, has a very interesting nutraceutical potential.

18.
Cureus ; 13(11): e19865, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34963865

RESUMO

Adenoviral infections in immunocompromised individuals may be life-threatening conditions. The aim of this review is to document all the reported cases of adenoviral infection is patients having undergone bone marrow transplantation (BMT). A comprehensive literature search of the databases Pubmed, Science Direct, and Google Scholar was conducted to identify all the case reports of adenoviral infections in BMT patients. A total of 30 articles with 44 patients were included. The most common underlying condition was acute lymphocytic leukemia (23%) followed by acute myeloid leukemia (18%). The most common site of infection was disseminated (50%), followed by liver infection (8%) and hemorrhagic cystitis (8%). Cidofovir was administered in 40.9% of the cases, and death was reported in 34.4% of them. Ribavirin was administered as monotherapy in 15.9% of patients, with a mortality rate of 57.1%. We found that the antiviral drug option had no statistically significant effect on the mortality rate (p=0.242). Also, the absence of graft-versus-host disease (GVHD) was not associated with an improved outcome (p=0.523). There was, however, a statistically significant difference in the outcome based on the site of infection (p=0.005), with a higher rate of mortality in the disseminated and gastrointestinal cases. To the best of our knowledge, this is the first review documenting all the cases of adenoviral infections in BMT patients. Future randomized studies are needed to validate the results of the present study.

19.
Vaccines (Basel) ; 8(2)2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32575876

RESUMO

There is a growing amount of evidence to support the beneficial role of a balanced intestinal microbiota, or distinct members thereof, in the manifestation and progression of malignant tumours, not only in the gastrointestinal tract but also in distant tissues as well. Intriguingly, bacterial species have been demonstrated to be indispensable modulatory agents of widely-used immunotherapeutic or chemotherapeutic regiments. However, the exact contribution of commensal bacteria to immunity, as well as to neoplasia formation and response to treatment, has not been fully elucidated, and most of the current knowledge acquired from animal models has yet to be translated to human subjects. Here, recent advances in understanding the interaction of gut microbes with the immune system and the modulation of protective immune responses to cancer, either naturally or in the context of widely-used treatments, are reviewed, along with the implications of these observations for future therapeutic approaches. In this regard, bacterial species capable of facilitating optimal immune responses against cancer have been surveyed. According to the findings summarized here, we suggest that strategies incorporating probiotic bacteria and/or modulation of the intestinal microbiota can be used as immune adjuvants, aiming to optimize the efficacy of cancer immunotherapies and conventional anti-tumour treatments.

20.
Cancers (Basel) ; 12(11)2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-33167430

RESUMO

BACKGROUND: Inducible Nitric Oxygen Synthase (iNOS) promotes the generation of NO in tissues. Its role in tumor progression and immune response is unclear. METHODS: The immunohistochemical expression patterns of iNOS were studied in a series of 98 tissue samples of non-small-cell lung carcinoma (NSCLC), in parallel with the expression of hypoxia and anaerobic metabolism markers, PD-L1 and tumor-infiltrating lymphocytes (TILs). RESULTS: iNOS is expressed by cancer cells in 19/98 (19.4%), while extensive expression by cancer-associated fibroblasts occurs in 8/98 (8.2%) cases. None of these patterns relate to stage or prognosis. Extensive infiltration of the tumor stroma by iNOS-expressing TILs (iNOS+TILs) occurs in 47/98 (48%) cases. This is related to low Hypoxia-Inducible Factor 1α (HIF1α), high PD-L1 expression and a better overall survival (p = 0.002). Expression of PD-L1, however, mitigates the beneficial effect of the presence of iNOS+TIL. CONCLUSIONS: Extensive expression of iNOS by TILs occurs in approximately 50% of NSCLCs, and this is significantly related to an improved overall survival. This brings forward the role of iNOS in anti-neoplastic lymphocyte biology, supporting iNOS+TILs as a putative marker of immune response. The value of this biomarker as a predictive and treatment-guiding tool for tumor immunotherapy demands further investigation.

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