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1.
Proc Natl Acad Sci U S A ; 118(39)2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34518374

RESUMO

Most endangered species exist today in small populations, many of which are isolated. Evolution in such populations is largely governed by genetic drift. Empirical evidence for drift affecting striking phenotypes based on substantial genetic data are rare. Approximately 37% of tigers (Panthera tigris) in the Similipal Tiger Reserve (in eastern India) are pseudomelanistic, characterized by wide, merged stripes. Camera trap data across the tiger range revealed the presence of pseudomelanistic tigers only in Similipal. We investigated the genetic basis for pseudomelanism and examined the role of drift in driving this phenotype's frequency. Whole-genome data and pedigree-based association analyses from captive tigers revealed that pseudomelanism cosegregates with a conserved and functionally important coding alteration in Transmembrane Aminopeptidase Q (Taqpep), a gene responsible for similar traits in other felid species. Noninvasive sampling of tigers revealed a high frequency of the Taqpep p.H454Y mutation in Similipal (12 individuals, allele frequency = 0.58) and absence from all other tiger populations (395 individuals). Population genetic analyses confirmed few (minimal number) tigers in Similipal, and its genetic isolation, with poor geneflow. Pairwise FST (0.33) at the mutation site was high but not an outlier. Similipal tigers had low diversity at 81 single nucleotide polymorphisms (mean heterozygosity = 0.28, SD = 0.27). Simulations were consistent with founding events and drift as possible drivers for the observed stark difference of allele frequency. Our results highlight the role of stochastic processes in the evolution of rare phenotypes. We highlight an unusual evolutionary trajectory in a small and isolated population of an endangered species.


Assuntos
Evolução Biológica , Deriva Genética , Variação Genética , Genética Populacional , Melanose/genética , Fenótipo , Tigres/fisiologia , Sequência de Aminoácidos , Animais , Conservação dos Recursos Naturais , Espécies em Perigo de Extinção , Genoma , Genótipo , Índia , Repetições de Microssatélites , Homologia de Sequência , Tigres/genética
2.
Int J Mol Sci ; 24(3)2023 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-36768834

RESUMO

Potatoes are developed vegetatively from tubers, and therefore potato virus transmission is always a possibility. The potato leafroll virus (PLRV) is a highly devastating virus of the genus Polerovirus and family Luteoviridae and is regarded as the second-most destructive virus after Potato virus Y. Multiple species of aphids are responsible for the persistent and non-propagating transmission of PLRV. Due to intrinsic tuber damage (net necrosis), the yield and quality are drastically diminished. PLRV is mostly found in phloem cells and in extremely low amounts. Therefore, we have attempted to detect PLRV in both potato tuber and leaves using a highly sensitive, reliable and cheap method of one-step reverse transcription-recombinase polymerase amplification (RT-RPA). In this study, an isothermal amplification and detection approach was used for efficient results. Out of the three tested primer sets, one efficiently amplified a 153-bp product based on the coat protein gene. In the present study, there was no cross-reactivity with other potato viruses and the optimal amplification reaction time was thirty minutes. The products of RT-RPA were amplified at a temperature between 38 and 42 °C using a simple heating block/water bath. The present developed protocol of one-step RT-RPA was reported to be highly sensitive for both leaves and tuber tissues equally in comparison to the conventional reverse transcription-polymerase chain reaction (RT-PCR) method. By using template RNA extracted employing a cellular disc paper-based extraction procedure, the method was not only simplified but it detected the virus as effectively as purified total RNA. The simplified one-step RT-RPA test was proven to be successful by detecting PLRV in 129 samples of various potato cultivars (each consisting of leaves and tubers). According to our knowledge, this is the first report of a one-step RT-RPA performed using simple RNA extracted from cellular disc paper that is equally sensitive and specific for detecting PLRV in potatoes. In terms of versatility, durability and the freedom of a highly purified RNA template, the one-step RT-RPA assay exceeds the RT-PCR assay, making it an effective alternative for the certification of planting materials, breeding for virus resistance and disease monitoring.


Assuntos
Luteoviridae , Solanum tuberosum , Viroses , Transcrição Reversa , Recombinases/genética , Solanum tuberosum/genética , Melhoramento Vegetal , Luteoviridae/genética , RNA , Nucleotidiltransferases/genética
3.
Mol Biol Rep ; 49(8): 7475-7481, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35585378

RESUMO

Diamondback moth, Plutella xylostella is one of the important pests of cole crops, the larval stages cause damage to leaves from seedling stage to the harvest thus reducing the quality and quantity of the yield. The insect gut posses a large variety of microbial communities among which, the association of bacteria is the most spread and common. Due to variations in various agro-climatic factors, the insect often assumes the status of major pest. These geographical variations in insects influence various biological parameters including insecticide resistance due to diversity of microbes/bacteria. The diverse role of gut bacteria in insect fitness traits has now gained perspectives for biotechnological exploration. The present study was aimed to determine the diversity of larval gut bacteria of diamondback moth collected from five different geographical regions of India. The gut bacteria of this pest were found to be influenced by different geographical regions. A total of 14 larval gut bacterial isolates were obtained. Majority of these bacteria belong to Enterobacteriaceae followed by Yersiniaceae, Morganellaceae and Enterococcaceae. Phylogeny analysis of all the bacterial isolates collected from five different geographical regions of India revealed that all the isolated strains are resolved in well-defined clades with their closest type species.


Assuntos
Mariposas , Animais , Bactérias , Resistência a Inseticidas , Larva , Filogenia
4.
Plant Mol Biol ; 105(4-5): 385-403, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33206359

RESUMO

KEY MESSAGE: We report that discriminate interaction between the expanded mitochondrial chaperone network and variability in their expression might determine their functional specificities and impart robustness to mitochondrial import processes in plants. Mitochondrial Hsp70 (mtHsp70), the central component of the pre-sequence associated motor (PAM) complex, is crucial for the import of proteins to the mitochondrial matrix. Activity of mtHsp70 is regulated by a heterodimeric complex of two J-domain proteins (JDPs), Pam18 and Pam16. Compared to other eukaryotes, plants harbor multiple copies of these JDPs, which posit that plants have an increasingly complex mtHsp70: JDP network in their mitochondrial matrix. Here, we show that although highly similar in sequence, some of the plant JDPs are functionally different. Protein: protein interaction studies including yeast two-hybrid and Bimolecular Fluorescence Complementation revealed that while all the AtPam18s interacted with AtPam16s, the strengths of these promiscuous interactions are variable. Further, down-regulation of AtPAM16L affected seed germination, even in the presence of its seemingly identical paralog, AtPAM16. Knockdown of AtPAM16L caused reduction in mitochondrial number and deregulation of several mitochondrial genes, suggesting towards a specific role of AtPam16L in maintaining mitochondrial homeostasis, especially under stress conditions. Our findings suggest that variations in the spatio-temporal expression, accompanied by discriminate interactions between the JDPs, might be defining the functional specificity of the mtHsp70 co-chaperone machinery and providing resilience to mitochondrial import processes in plants, especially under stress conditions.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Proteínas Mitocondriais/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Proteínas de Choque Térmico HSP70/química , Proteínas de Choque Térmico HSP70/genética , Mitocôndrias/genética , Proteínas de Transporte da Membrana Mitocondrial/química , Proteínas de Transporte da Membrana Mitocondrial/genética , Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial , Proteínas Mitocondriais/química , Proteínas Mitocondriais/genética , Mutação , Plantas Geneticamente Modificadas , Ligação Proteica , Domínios Proteicos , Transporte Proteico/genética
5.
Blood ; 122(14): e23-32, 2013 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-23980067

RESUMO

Mesenchymal stem cells (MSCs) are promising candidates for cell-based therapy to treat several diseases and are compelling to consider as vehicles for delivery of biological agents. However, MSCs appear to act through a seemingly limited "hit-and-run" mode to quickly exert their therapeutic impact, mediated by several mechanisms, including a potent immunomodulatory secretome. Furthermore, MSC immunomodulatory properties are highly variable and the secretome composition following infusion is uncertain. To determine whether a transiently controlled antiinflammatory MSC secretome could be achieved at target sites of inflammation, we harnessed mRNA transfection to generate MSCs that simultaneously express functional rolling machinery (P-selectin glycoprotein ligand-1 [PSGL-1] and Sialyl-Lewis(x) [SLeX]) to rapidly target inflamed tissues and that express the potent immunosuppressive cytokine interleukin-10 (IL-10), which is not inherently produced by MSCs. Indeed, triple-transfected PSGL-1/SLeX/IL-10 MSCs transiently increased levels of IL-10 in the inflamed ear and showed a superior antiinflammatory effect in vivo, significantly reducing local inflammation following systemic administration. This was dependent on rapid localization of MSCs to the inflamed site. Overall, this study demonstrates that despite the rapid clearance of MSCs in vivo, engineered MSCs can be harnessed via a "hit-and-run" action for the targeted delivery of potent immunomodulatory factors to treat distant sites of inflammation.


Assuntos
Engenharia Genética/métodos , Imunossupressores/administração & dosagem , Interleucina-10/administração & dosagem , Células-Tronco Mesenquimais/metabolismo , Animais , Sistemas de Liberação de Medicamentos/métodos , Humanos , Inflamação/tratamento farmacológico , Transplante de Células-Tronco Mesenquimais/métodos , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro , Transfecção
6.
Neurol India ; 63(5): 681-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26448225

RESUMO

OBJECTIVES: Giant cell arteritis (GCA) is a granulomatous large vessel vasculitis with very scarce data from India. The purpose of this study was to present a comprehensive data of all published Indian cases along with our experience from North India. MATERIALS AND METHODS: This was a retrospective study of all patients diagnosed to be having GCA according to the American College of Rheumatology criteria at a large tertiary care hospital. The demographic data, clinical, investigations, treatment details, and outcomes were noted. Details of all case series and case reports published from India were pooled along with our experience in order to generate a cumulative data of all cases from India. This was then compared with several large published case series from South America, Europe, and Asia. RESULTS: A total of 72 patients (17 patients in the present series and another 55 patients from other Indian case series and case reports) were identified. The findings of our study are similar to the studies published from other parts of the world, except for the onset of the disease a decade earlier, a male predilection, a lower temporal artery biopsy positivity, and a higher incidence of ophthalmic complications. CONCLUSIONS: Indian patients with GCA have an earlier age of onset, male preponderance, and higher ophthalmic complications.

7.
Heliyon ; 10(4): e26718, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38434015

RESUMO

Soil salinity has emerged as a critical abiotic stress in potato production, whereas wilt disease, caused by Fusarium solani, is the significant biotic stress. An experiment was performed to decipher the occurrence of wilt incidence by F. solani FJ1 under the influence of salinity in both in vitroand pot culture conditions. High salt concentration negatively influenced root and shoot development in the variety "Kufri Jyoti" but positively affected the mycelial growth and sporulation behaviours of F. solani FJ1. There was abundant whitish mycelial growth with enhanced biomass and high sporulation (microconidia production) in F. solani FJ1 cultured on salt-supplemented media. Moreover, under high salinity conditions (EC 2-8 dS m-1), severe wilting and rotting of vascular bundles were observed in plants artificially inoculated with F. solani FJ1. The mortality rate of potato plants was significantly higher under individual and combined stresses as compared to control. The wilt index of individual and combined stressed plants was also substantially higher compared to the control. Additionally, compared to the control, there was a significant decrease in total chlorophyll content and membrane stability index of the leaves under combined stress. However, the total phenols were increased under stress conditions. The total sugar content of potato plants decreased in infected plants, but increased when exposed to salt stress or a combination of salt stress and pathogen infection. F. solani infection also increased the activity of peroxidase (POX) and decreased the activity of phenylalanine ammonia-lyase (PAL) and catalase (CAT). These results suggest that Fusarium wilt and dry rot will be a more severe disease for potato cultivation in saline soils.

8.
Cancer Res ; 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38959335

RESUMO

The TP53 tumor suppressor is frequently altered in lethal, castration-resistant prostate cancer (CRPC). However, to date there are no effective treatments that specifically target TP53 alterations. Using transcriptomic and metabolomic analyses, we showed here that TP53-altered prostate cancer (PCa) exhibits an increased dependency on asparagine and overexpresses asparagine synthetase (ASNS), the enzyme catalyzing the synthesis of asparagine. Mechanistically, loss or mutation of TP53 transcriptionally activated ASNS expression, directly as well as via mTORC1-mediated ATF4 induction, driving de novo asparagine biosynthesis to support CRPC growth. TP53-altered CRPC cells were sensitive to asparagine restriction by knockdown of ASNS or L-asparaginase treatment to deplete the intracellular and extracellular sources of asparagine, respectively, and cell viability was rescued by asparagine addition. Notably, pharmacological inhibition of intracellular asparagine biosynthesis using a glutaminase inhibitor and depletion of extracellular asparagine with L-asparaginase significantly reduced asparagine production and effectively impaired CRPC growth. This study highlights the significance of ASNS-mediated metabolic adaptation as a synthetic vulnerability in CRPC with TP53 alterations, providing a rationale for targeting asparagine production to treat these lethal prostate cancers.

9.
J Fungi (Basel) ; 9(4)2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-37108920

RESUMO

Potato dry rot disease caused by multiple Fusarium species is a major global concern in potato production. In this investigation, the tubers of cultivars Kufri Jyoti and Kufri Frysona were artificially inoculated with an individual or combined inoculum of Fusarium sambucinum and Fusarium solani. Fusarium sambucinum caused a significantly higher lesion development (p < 0.01) than Fusarium solani, irrespective of cultivars. The combined inoculum of both the Fusarium species caused significantly higher rot development (p < 0.005) in inoculated tubers. Analyses of starch and amylose content revealed that individual or mixed infection of fungi caused a significant reduction (p < 0.005) in these parameters compared to healthy tubers. The increased starch digestibility due to fungal infection caused a higher glycemic index and glycemic load. The resistant starch also deteriorated in the infected potato tubers as compared to the control. Kufri Jyoti showed a higher starch and amylose content reduction in response to the treatments compared to Kufri Frysona. The correlation analysis demonstrated a negative correlation in lesion diameter and rot volume with starch and amylose content (p < -0.80). However, the glycemic index and resistant starch were positively correlated with lesion development. Altogether, these findings highlight the progressive deterioration of quality parameters, which will be a critical concern for processing industry stakeholders and consumers.

10.
3 Biotech ; 13(11): 373, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37854940

RESUMO

Vegetative propagation of potatoes makes it possible for potato viruses to be transmitted through tubers. Potato virus A (PVA) is one of these viruses, which belongs to the Potyvirus genus in the Potyviridae family. Potato tuber yield can be reduced by 30-40% by PVA alone. Losses can be further exacerbated by potato virus X and/or potato virus Y infection. PVA is transmitted primarily by several species of aphids in non-persistent manner. With the aim of resolving this problem, we developed one-step reverse transcription-recombinase polymerase amplification (RT-RPA), a highly sensitive and cost-effective method for detecting PVA in both potato tubers and leaves. Detection and amplification are performed using isothermal conditions in this method. There was good amplification of the coat protein gene in PVA with all three primers tested. To conduct this study, a primer set that can amplify specific 185 base pair (bp) product was selected. PVA detection was optimized by 30-min amplification reactions, which showed no cross-reactivity with other potato viruses. A simple heating block or water bath was used to amplify PVA product using RT-RPA at a temperature range of 38-42 °C. In comparison to conventional reverse transcription-polymerase chain reaction (RT-PCR), the newly developed RT-RPA protocol exhibited high sensitivity for both potato leaves and tuber tissues. Using cellular paper-based simple RNA extraction procedure, the virus was detected in leaf samples as efficiently as purified total RNA. We also found that combining LiCl-based RNA precipitation with cellular paper discs allowed us to successfully optimize RNA extraction for one-step RT-RPA for detecting PVA in tubers. Tests using this simplified one-step RT-RPA method were successfully applied to 300 samples of both leaves and tubers from various potato cultivars. In our knowledge, this is the first report of an RT-RPA assay utilizing simple RNA obtained from either cellular disc paper or LiCl coupled with cellular disc paper to detect PVA. As a result, this method was equally sensitive and specific for detecting PVA in potatoes. The developed RT-RPA assay is more versatile, durable, and do not require highly purified RNA templates, thus providing an effective alternative to RT-PCR assays for screening of germplasm, certifying planting materials, breeding for virus resistance, and real-time monitoring of PVA.

11.
J Neurooncol ; 107(2): 289-97, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22102081

RESUMO

The search for molecular markers which predict response to chemotherapy is an important aspect of current neuro-oncology research. MGMT promoter methylation is the only proved marker of glioblastoma. The purpose of this study was to assess the effect of topoisomerase expression on glioblastoma survival and study the mechanisms involved. The transcript levels of all isoforms of the topoisomerase family in all grades of diffuse astrocytoma were assessed. A prospective study of patients with glioblastoma treated by a uniform treatment procedure was performed with the objective of correlating outcome with gene expression. The ability of TOP2A enzyme to relax the super coiled plasmid DNA in the presence of temozolomide was evaluated to assess its effect on TOP2A. The temozolomide cyctotoxicity of TOP2A-silenced U251 cells was assessed. The transcript levels of TOP2A, TOP2B, and TOP3A are upregulated significantly in GBM in comparison with lower grades of astrocytoma and normal brain samples. mRNA levels of TOP2A correlated significantly with survival of the patients. Higher TOP2A transcript levels in GBM patients predicted better prognosis (P = 0.043; HR = 0.889). Interestingly, we noted that temozolomide inhibited TOP2A activity in in-vitro enzyme assays. We also noted that siRNA knock down of TOP2A rendered a glioma cell line resistant to temozolomide chemotherapy. We demonstrated for the first time that temozolomide is also a TOP2A inhibitor and established that TOP2A transcript levels determine the chemosensitivity of glioblastoma to temozolomide therapy. Very high levels of TOP2A are a good prognostic indicator in GBM patients receiving temozolomide chemotherapy.


Assuntos
Antígenos de Neoplasias/metabolismo , Neoplasias Encefálicas/metabolismo , DNA Topoisomerases Tipo II/metabolismo , Proteínas de Ligação a DNA/metabolismo , Dacarbazina/análogos & derivados , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/metabolismo , Inibidores da Topoisomerase II/farmacologia , Antígenos de Neoplasias/genética , Antineoplásicos/farmacologia , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/mortalidade , Camptotecina/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Estudos de Coortes , DNA Topoisomerases Tipo II/genética , Proteínas de Ligação a DNA/genética , Dacarbazina/farmacologia , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Glioblastoma/diagnóstico , Glioblastoma/mortalidade , Humanos , Masculino , Proteínas de Ligação a Poli-ADP-Ribose , Prognóstico , RNA Mensageiro/metabolismo , Temozolomida
12.
Philos Trans R Soc Lond B Biol Sci ; 377(1852): 20200418, 2022 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-35430878

RESUMO

Unprecedented advances in sequencing technology in the past decade allow a better understanding of genetic variation and its partitioning in natural populations. Such inference is critical to conservation: to understand species biology and identify isolated populations. We review empirical population genetics studies of Endangered Bengal tigers within India, where 60-70% of wild tigers live. We assess how changes in marker type and sampling strategy have impacted inferences by reviewing past studies, and presenting three novel analyses including a single-nucleotide polymorphism (SNP) panel, genome-wide SNP markers, and a whole-mitochondrial genome network. At a broad spatial scale, less than 100 SNPs revealed the same patterns of population clustering as whole genomes (with the exception of one additional population sampled only in the SNP panel). Mitochondrial DNA indicates a strong structure between the northeast and other regions. Two studies with more populations sampled revealed further substructure within Central India. Overall, the comparison of studies with varied marker types and sample sets allows more rigorous inference of population structure. Yet sampling of some populations is limited across all studies, and these should be the focus of future sampling efforts. We discuss challenges in our understanding of population structure, and how to further address relevant questions in conservation genetics. This article is part of the theme issue 'Celebrating 50 years since Lewontin's apportionment of human diversity'.


Assuntos
Tigres , Animais , Conservação dos Recursos Naturais , Espécies em Perigo de Extinção , Variação Genética , Genética Populacional , Índia , Estudos Prospectivos , Tigres/genética
13.
J Virol Methods ; 307: 114568, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35718004

RESUMO

Potato virus S (PVS) is a noteworthy threat to the propagation of healthy seed potatoes. Accurate and speedy detection is critical for effective PVS management. In the present study, an isothermal-based one-step reverse transcription-recombinase polymerase amplification (RT-RPA) approach was developed to detect PVS infection in potato leaves and tubers. A primer set based on the coat protein gene successfully amplified a 158 bp product out of three primer sets examined. The amplification reaction took less than 30 min to complete with no account of cross-reactivity with major potato viruses. Additionally, amplification of RT-RPA products was performed on the heating system and/or water bath at 38-42 °C. The results of sensitivity analysis revealed that one-step RT-RPA has shown 100 times higher sensitivity than routine RT-PCR for the detection of PVS in infected leaves. Furthermore, ten times higher sensitivity of RT-RPA was observed in infected tubers. The methodology was simplified further by the use of template RNA extracted using a cellular disc paper-based extraction method that detected the PVS more effectively than purified total RNA. PVS was detected in 175 samples (leaves and tubers each) of several potato varieties using this innovative technique. To our acquaintance, this is the first report of one-step RT-RPA using a basic RNA extract derived through cellular disc paper that is significantly sensitive and precise for PVS detection in potatoes. The advantages of one-step RT-RPA in terms of proficiency, robustness, and the availability of a highly pure RNA template make it an attractive choice for seed accreditation, resistance breeding, and field inspections.


Assuntos
Transcrição Reversa , Solanum tuberosum , Carlavirus , Técnicas de Amplificação de Ácido Nucleico/métodos , Doenças das Plantas , RNA , Recombinases/genética , Sensibilidade e Especificidade
14.
Methods Mol Biol ; 2408: 211-226, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35325425

RESUMO

Double-stranded RNA (dsRNAs) molecules are the precursors and effective triggers of RNAi in most organisms. RNAi can be induced by the direct introduction of dsRNAs in plants, fungi, insects, and nematodes. Until now RNAi is usually established by transformation of the plant with a construct that produces hairpin RNAs. Alternatively, advances in RNA biology demonstrated efficiently the in vitro method of large-scale synthesis of dsRNA molecule. Here we describe the de novo synthesis of dsRNA molecule targeting the specific gene of interest for functional application. Selection of off-target effective siRNA regions, flanking of T7 promoter sequences, T7 polymerase reaction, and maintenance of the stability of dsRNA molecules are the main criteria of this method to obtain pure and effective yield for functional applications. IPTG (isopropyl-ß-D-thiogalactopyranoside) induced, T7 express E. coli cells, could be used for large scale synthesis of dsRNA molecule are also described in this method.


Assuntos
Escherichia coli , RNA de Cadeia Dupla , Escherichia coli/genética , Plantas/genética , Interferência de RNA , RNA de Cadeia Dupla/genética , RNA Interferente Pequeno
15.
Clin Genitourin Cancer ; 20(6): 575-580, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36210299

RESUMO

INTRODUCTION: Ephrin receptors and their membrane-localized ligands induce bidirectional signaling and facilitate tumor-stroma interactions. Blocking the EphB4-EphrinB2 pathway, which can be accomplished by soluble EphB4 conjugated to human serum albumin (sEphB4-HSA), promotes cell death in preclinical models of aggressive prostate cancer. We hypothesized that targeting the EphB4-EphrinB2 pathway may serve as a therapeutic target in the treatment of metastatic castration resistant prostate cancer (mCRPC). PATIENTS AND METHODS: We conducted a single arm, phase II trial in patients with progressive mCRPC who had received no more than 3 prior therapies for mCRPC. sEphB4-HSA 1000 mg IV was administered every 2 weeks, extending to 3 weeks starting from cycle 7. The primary endpoint was confirmed prostate specific antigen (PSA) response rate. We employed a Simon 2-stage Minimax design with 15 patients in the first stage and 10 additional patients in the second stage. RESULTS: Fourteen eligible patients enrolled in the study with median age of 73.5 years (range: 52-83) and median baseline PSA of 65.11 ng/mL (range: 7.77-2850 ng/mL). Most patients received 3 prior therapies for mCRPC. The median treatment duration with sEphB4-HSA was 6.5 weeks (range: 2-35 weeks). Three patients experienced a serious adverse event potentially related to therapy, including 1 patient with a grade 5 event (cerebral vascular accident) possibly related to the study drug. No patient had a confirmed PSA response, and the study was stopped for futility. Thirteen patients had PSA progression. The median time to PSA progression was 28 days (90% CI: 28-42 days), and median time to radiologic progression was 55 days (90% CI: 54-72 days). Of 3 patients with measurable disease, 2 had stable disease and one had progressive disease. CONCLUSION: In patients with mCRPC who progressed on prior second generation AR-targeted therapy, sEphB4-HSA monotherapy had no discernable anti-tumor activity.


Assuntos
Neoplasias de Próstata Resistentes à Castração , Masculino , Humanos , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Neoplasias de Próstata Resistentes à Castração/patologia , Antígeno Prostático Específico , Inibidores da Angiogênese/uso terapêutico , Resultado do Tratamento
16.
Sci Adv ; 8(17): eabh3635, 2022 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-35476451

RESUMO

MYC regulates multiple gene programs, raising questions about the potential selectivity and downstream transcriptional consequences of MYC inhibitors as cancer therapeutics. Here, we examined the effect of a small-molecule MYC inhibitor, MYCi975, on the MYC/MAX cistromes, epigenome, transcriptome, and tumorigenesis. Integrating these data revealed three major classes of MYCi975-modulated gene targets: type 1 (down-regulated), type 2 (up-regulated), and type 3 (unaltered). While cell cycle and signal transduction pathways were heavily targeted by MYCi, RNA biogenesis and core transcriptional pathway genes were spared. MYCi975 altered chromatin binding of MYC and the MYC network family proteins, and chromatin accessibility and H3K27 acetylation alterations revealed MYCi975 suppression of MYC-regulated lineage factors AR/ARv7, FOXA1, and FOXM1. Consequently, MYCi975 synergistically sensitized resistant prostate cancer cells to enzalutamide and estrogen receptor-positive breast cancer cells to 4-hydroxytamoxifen. Our results demonstrate that MYCi975 selectively inhibits MYC target gene expression and provide a mechanistic rationale for potential combination therapies.


Assuntos
Neoplasias da Mama , Epigenômica , Cromatina/genética , Expressão Gênica , Humanos , Masculino , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo
17.
Cancer Res ; 82(11): 2110-2123, 2022 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-35405009

RESUMO

Androgen receptor (AR) pathway inhibitors are the mainstay treatment for advanced prostate cancer, but resistance to therapy is common. Here, we used a CRISPR activation screen in metastatic castration-sensitive prostate cancer cells to identify genes that promote resistance to AR inhibitors. Activation of the TGFß target gene paired-related homeobox2 (PRRX2) promoted enzalutamide resistance. PRRX2 expression was the highest in double-negative prostate cancer (DNPC), which lack AR signaling and neuroendocrine differentiation, and a PRRX2-related gene signature identified a subset of patients with DNPC with reduced overall survival. PRRX2-expressing cells showed alterations in the CDK4/6/Rb/E2F and BCL2 pathways. Accordingly, treatment with CDK4/6 and BCL2 inhibitors sensitized PRRX2-expressing, castration-resistant tumors to enzalutamide. Overall, PRRX2 was identified as a driver of enzalutamide resistance. The PRRX2 signature merits investigation as a biomarker of enzalutamide resistance in prostate cancer that could be reversed with CDK4/6 and BCL2 inhibitors. SIGNIFICANCE: PRRX2 mediates enzalutamide resistance via activation of the E2F and BCL2 pathways, which can be targeted with CDK4/6 and BCL2 inhibitors to reverse resistance.


Assuntos
Antineoplásicos , Neoplasias de Próstata Resistentes à Castração , Antagonistas de Receptores de Andrógenos/farmacologia , Antineoplásicos/farmacologia , Benzamidas , Linhagem Celular Tumoral , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Resistencia a Medicamentos Antineoplásicos/genética , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Masculino , Nitrilas/uso terapêutico , Feniltioidantoína , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptores Androgênicos/metabolismo
18.
Prostate Cancer Prostatic Dis ; 25(3): 463-471, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-34035460

RESUMO

BACKGROUND: Inflammatory bowel disease (IBD) has been implicated as a risk factor for prostate cancer, however, the mechanism of how IBD leads to prostate tumorigenesis is not known. Here, we investigated whether chronic intestinal inflammation leads to pro-inflammatory changes associated with tumorigenesis in the prostate. METHODS: Using clinical samples of men with IBD who underwent prostatectomy, we analyzed whether prostate tumors had differences in lymphocyte infiltrate compared to non-IBD controls. In a mouse model of chemically-induced intestinal inflammation, we investigated whether chronic intestinal inflammation could be transferred to the wild-type mouse prostate. In addition, mouse prostates were evaluated for activation of pro-oncogenic signaling and genomic instability. RESULTS: A higher proportion of men with IBD had T and B lymphocyte infiltration within prostate tumors. Mice with chronic colitis showed significant increases in prostatic CD45 + leukocyte infiltration and elevation of three pro-inflammatory cytokines-TIMP-1, CCL5, and CXCL1 and activation of AKT and NF-kB signaling pathways. Lastly, mice with chronic colitis had greater prostatic oxidative stress/DNA damage, and prostate epithelial cells had undergone cell cycle arrest. CONCLUSIONS: These data suggest chronic intestinal inflammation is associated with an inflammatory-rich, pro-tumorigenic prostatic phenotype which may explain how gut inflammation fosters prostate cancer development in men with IBD.


Assuntos
Colite , Doenças Inflamatórias Intestinais , Neoplasias da Próstata , Animais , Carcinogênese , Colite/induzido quimicamente , Colite/metabolismo , Colite/patologia , Sulfato de Dextrana/efeitos adversos , Modelos Animais de Doenças , Humanos , Inflamação , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Próstata/patologia , Neoplasias da Próstata/genética
19.
Cancer Res ; 81(8): 2157-2170, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33637566

RESUMO

Neuroendocrine prostate cancer (NEPC) is an aggressive subtype of prostate cancer with poor prognosis, and there is a critical need for novel therapeutic approaches. NEPC is associated with molecular perturbation of several pathways, including amplification of MYCN. Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase involved in the pathogenesis of neuroblastoma and other malignancies where it cooperates with N-Myc. We previously identified the first case of ALK F1174C-activating mutation in a patient with de novo NEPC who responded to the ALK inhibitor, alectinib. Here, we show that coactivation of ALK and N-Myc (ALK F1174C/N-Myc) is sufficient to transform mouse prostate basal stem cells into aggressive prostate cancer with neuroendocrine differentiation in a tissue recombination model. A novel gene signature from the ALK F1174C/N-Myc tumors was associated with poor outcome in multiple human prostate cancer datasets. ALK F1174C and ALK F1174C/N-Myc tumors displayed activation of the Wnt/ß-catenin signaling pathway. Chemical and genetic ALK inhibition suppressed Wnt/ß-catenin signaling and tumor growth in vitro in NEPC and neuroblastoma cells. ALK inhibition cooperated with Wnt inhibition to suppress NEPC and neuroblastoma proliferation in vitro and tumor growth and metastasis in vivo. These findings point to a role for ALK signaling in NEPC and the potential of cotargeting the ALK and Wnt/ß-catenin pathways in ALK-driven tumors. Activated ALK and N-Myc are well known drivers in neuroblastoma development, suggesting potential similarities and opportunities to elucidate mechanisms and therapeutic targets in NEPC and vice versa. SIGNIFICANCE: These findings demonstrate that coactivation of ALK and N-Myc induces NEPC by stimulating the Wnt/ß-catenin pathway, which can be targeted therapeutically.


Assuntos
Quinase do Linfoma Anaplásico/metabolismo , Carcinoma Neuroendócrino/etiologia , Proteína Proto-Oncogênica N-Myc/metabolismo , Neoplasias da Próstata/etiologia , Via de Sinalização Wnt , Quinase do Linfoma Anaplásico/antagonistas & inibidores , Quinase do Linfoma Anaplásico/genética , Animais , Carbazóis/uso terapêutico , Carcinoma Neuroendócrino/tratamento farmacológico , Carcinoma Neuroendócrino/metabolismo , Carcinoma Neuroendócrino/patologia , Linhagem Celular Tumoral , Proliferação de Células , Transformação Celular Neoplásica/genética , Humanos , Masculino , Camundongos , Mutação , Proteína Proto-Oncogênica N-Myc/genética , Células-Tronco Neoplásicas , Neuroblastoma/tratamento farmacológico , Neuroblastoma/etiologia , Neuroblastoma/patologia , Piperidinas/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Inibidores de Proteínas Quinases/uso terapêutico , Sequenciamento do Exoma , Via de Sinalização Wnt/efeitos dos fármacos , Via de Sinalização Wnt/genética
20.
Cardiol Res Pract ; 2021: 5551031, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34258054

RESUMO

The present study aimed at investigating the 4G/5G and -844G/A polymorphisms and plasma concentration of PAI-1 in patients with acute myocardial infarction (AMI) and chronic stable angina (CSA) in Indian population. It included 100 patients with AMI and stable angina and 100 healthy controls. All study subjects were typed for two PAI polymorphisms (4G/5G and -844G/A) through PCR-RFLP and level of PAI through ELISA. The comparison of AMI and CSA independently with control in terms of PAI-1 level was statistically significant but not between AMI and CSA. The frequency of 4G/4G and 4G/5G genotype and 4G allele was significantly higher in AMI cases than in control and was found to increase the risk of AMI. There was a significant relationship between 4G/5G polymorphism and AMI risk under the dominant and codominant genotype. The frequency of 4G/4G genotype and 4G allele was significantly higher in CSA cases than in control group and increases the risk of CSA. There was no significant association between 4G/5G polymorphism and CSA risk under recessive, dominant, and codominant models. The genotype and allelic frequencies difference between the cases (AMI and CSA) and control with regard to -844G/A polymorphisms were statistically nonsignificant. Also, we did not detect any significant association of -844G/A polymorphism with AMI and CSA in recessive, dominant, and codominant models. Along with the traditional risk factors, the 4G/5G allele polymorphism is an independent risk factor for the development of AMI. The detection of 4G/5G allele may therefore be helpful in primary prevention. Patients who carry the 4G/5G allele polymorphism have high concentrations of PAI-1, which might be involved in incidents leading to AMI. The present study for the first time revealed significant association of 4G/5G allele polymorphism with high risk of AMI in Indian population and will be helpful in identifying the genetic risk factors associated with AMI and CSA and for better management of diagnostic measures.

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