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1.
J Fungi (Basel) ; 10(6)2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38921405

RESUMO

Fusarium wilt of banana (FWB) is the most limiting disease in this crop. The phytosanitary emergency caused by FWB since 2019 in Colombia has required the development of ecofriendly control methods. The aim of this study was to test the effectiveness of microbial-based biofungicides against FWB caused by Fusarium oxysporum f. sp. cubense race 1 (Foc R1) and correlate such effect with plant physiological parameters. Five Trichoderma (T1 to T4 and T9) and four Bacillus (T5 to T8)-based biofungicides were evaluated in pot experiments. In vitro, dual confrontation tests were also carried out to test whether the in vitro effects on Foc growth were consistent with the in vivo effects. While Trichoderma-based T3, T4, and T9, and Bacillus-based T8, significantly reduced the growth of Foc R1 in vitro, Trichoderma-based T1, T3, T4, and T9 temporarily reduced the Foc population in the soil. However, the incidence progress of FWB was significantly reduced by Bacterial-based T7 (74% efficacy) and Trichoderma-based T2 (50% efficacy). The molecular analysis showed that T7 prevented the inner tissue colonization by Foc R1 in 80% of inoculated plants. The T2, T4, T7, and T9 treatments mitigated the negative effects caused by Foc R1 on plant physiology and growth. Our data allowed us to identify three promising treatments to control FWB, reducing the progress of the disease, delaying the colonization of inner tissue, and mitigating physiological damages. Further studies should be addressed to determine the modes of action of the biocontrol agents against Foc and validate the utilization in the field.

2.
Mol Biol Rep ; 51(1): 504, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38616219

RESUMO

BACKGROUND: Mycobacterium leprae causes leprosy that is highly stigmatized and chronic infectious skin disease. Only some diagnostic tools are being used for the identification M. leprae in clinical samples, such as bacillary detection, and histopathological tests. These methods are invasive and often have low sensitivity. Currently, the PCR technique has been used as an effective tool fordetecting M. leprae DNA across different clinical samples. The current study aims to detect M. leprae DNA in urine samples of untreated and treated leprosy patients using the Rlep gene (129 bp) and compared the detection among Ridley-Jopling Classification. METHODS: Clinical samples (Blood, Urine, and Slit Skin Smears (SSS)) were collected from leprosy and Non-leprosy patients. DNA extraction was performed using standard laboratory protocol and Conventional PCR was carried out for all samples using Rlep gene target and the amplicons of urine samples were sequenced by Sanger sequencing to confirm the Rlep gene target. RESULTS: The M. leprae DNA was successfully detected in all clinical samples across all types of leprosy among all the study groups using RLEP-PCR. Rlep gene target was able to detect the presence of M. leprae DNA in 79.17% of urine, 58.33% of blood, and 50% of SSS samples of untreated Smear-Negative leprosy patients. The statistical significant difference (p = 0.004) was observed between BI Negative (Slit Skin Smear test) and RLEP PCR positivity in urine samples of untreated leprosy group. CONCLUSION: The PCR positivity using Rlep gene target (129 bp) was highest in all clinical samples among the study groups, across all types of leprosy. Untreated tuberculoid and PNL leprosy patients showed the highest PCR positivity in urine samples, indicating its potential as a non-invasive diagnostic tool for leprosy and even for contact screening.


Assuntos
Bacillus , Mycobacterium leprae , Humanos , Mycobacterium leprae/genética , Pele , Firmicutes , Reação em Cadeia da Polimerase
3.
Cancers (Basel) ; 15(7)2023 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-37046811

RESUMO

BACKGROUND: The aim of this study was to develop and validate radiogenomic models to predict the MDM2 gene amplification status and differentiate between ALTs and lipomas on preoperative MR images. METHODS: MR images were obtained in 257 patients diagnosed with ALTs (n = 65) or lipomas (n = 192) using histology and the MDM2 gene analysis as a reference standard. The protocols included T2-, T1-, and fat-suppressed contrast-enhanced T1-weighted sequences. Additionally, 50 patients were obtained from a different hospital for external testing. Radiomic features were selected using mRMR. Using repeated nested cross-validation, the machine-learning models were trained on radiomic features and demographic information. For comparison, the external test set was evaluated by three radiology residents and one attending radiologist. RESULTS: A LASSO classifier trained on radiomic features from all sequences performed best, with an AUC of 0.88, 70% sensitivity, 81% specificity, and 76% accuracy. In comparison, the radiology residents achieved 60-70% accuracy, 55-80% sensitivity, and 63-77% specificity, while the attending radiologist achieved 90% accuracy, 96% sensitivity, and 87% specificity. CONCLUSION: A radiogenomic model combining features from multiple MR sequences showed the best performance in predicting the MDM2 gene amplification status. The model showed a higher accuracy compared to the radiology residents, though lower compared to the attending radiologist.

4.
Front Microbiol ; 14: 1113318, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37051521

RESUMO

Background: Mycobacterium leprae transcriptomic and human host immune gene expression signatures that demonstrate a plausible association with type I (T1R) and type II reactions (T2R) aid in early diagnosis, prevention of nerve damage and consequent demyelinating neuropathy in leprosy. The aim of the study is to identify M. leprae and host-associated gene-expression signatures that are associated with reactional states in leprosy. Methods: The differentially expressed genes from the whole transcriptome of M. leprae were determined using genome-wide hybridization arrays with RNA extracted from skin biopsies of 20 T1R, 20 T2R and 20 non reactional controls (NR). Additionally, human immune gene-expressions were profiled using RT2-PCR profiler arrays and real-time qPCRs. Results: The RNA quality was optimal in 16 NR, 18 T1R and 19 T2R samples. Whole transcriptome expression array of these samples revealed significant upregulation of the genes that encode integral and intrinsic membrane proteins, hydrolases and oxidoreductases. In T1R lesional skin biopsy specimens, the top 10 significantly upregulated genes are ML2064, ML1271, ML1960, ML1220, ML2498, ML1996, ML2388, ML0429, ML2030 and ML0224 in comparison to NR. In T2R, genes ML2498, ML1526, ML0394, ML1960, ML2388, ML0429, ML0281, ML1847, ML1618 and ML1271 were significantly upregulated. We noted ML2664 was significantly upregulated in T1R and repressed in T2R. Conversely, we have not noted any genes upregulated in T2R and repressed in T1R. In both T1R and T2R, ML2388 was significantly upregulated. This gene encodes a probable membrane protein and epitope prediction using Bepipred-2.0 revealed a distinct B-cell epitope. Overexpression of ML2388 was noted consistently across the reaction samples. From the host immune gene expression profiles, genes for CXCL9, CXCL10, CXCL2, CD40LG, IL17A and CXCL11 were upregulated in T1R when compared to the NR. In T2R, CXCL10, CXCL11, CXCL9, CXCL2 and CD40LG were upregulated when compared to the NR group. Conclusion: A gene set signature involving bacterial genes ML2388, ML2664, and host immune genes CXCL10 and IL-17A can be transcriptomic markers for reactional states in leprosy.

5.
Phytopathology ; 113(1): 90-97, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36095335

RESUMO

The global banana industry is threatened by one of the most devastating diseases: Fusarium wilt of banana. Fusarium wilt of banana is caused by the soilborne fungus Fusarium oxysporum f. sp. cubense (Foc), which almost annihilated the banana production in the late 1950s. A new strain of Foc, known as tropical race 4 (TR4), attacks a wide range of banana varieties, including Cavendish clones, which are the source of 99% of banana exports. In 2019, Foc TR4 was reported in Colombia, and more recently (2021) in Peru. In this study, we sequenced three fungal isolates identified as Foc TR4 from La Guajira (Colombia) and compared them against 19 whole-genome sequences of Foc TR4 publicly available, including four genome sequences recently released from Peru. To understand the genetic relatedness of the Colombian Foc TR4 isolates and those from Peru, we conducted a phylogenetic analysis based on a genome-wide set of single nucleotide polymorphisms (SNPs). Additionally, we compared the genomes of the 22 available Foc TR4 isolates, looking for the presence-absence of gene polymorphisms and genomic regions. Our results reveal that (i) the Colombian and Peruvian isolates are genetically distant, which could be better explained by independent incursions of the pathogen to the continent, and (ii) there is a high correspondence between the genetic relatedness and geographic origin of Foc TR4. The profile of present/absent genes and the distribution of missing genomic regions showed a high correspondence to the clades recovered in the phylogenetic analysis, supporting the results obtained by SNP-based phylogeny.


Assuntos
Fusarium , Musa , Fusarium/genética , Filogenia , Doenças das Plantas/microbiologia , Sequência de Bases , América do Sul , Musa/microbiologia
6.
Children (Basel) ; 9(12)2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36553412

RESUMO

Guillain-Barré syndrome (GBS) represents a group of acute immune-mediated polyradiculoneuropathies that is usually characterized by symmetrical limb weakness and areflexia. GBS can also lead to atypical clinical findings, which may lead to confusion and errors in the diagnosis. In this report, we describe a case of Guillain-Barré syndrome in a 7-year-old child who presented with neck stiffness, headache and vomiting mimicking acute meningoencephalitis, arthritis and myositis. Symptoms of ascending paralysis developed subsequently. Clearly, the atypical presentation of GBS is a significant dilemma for pediatricians and may lead to delays in diagnosis and treatment.

7.
Open Forum Infect Dis ; 9(5): ofac160, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35493120

RESUMO

We present a novel case of recurrent brain abscesses found to be the result of a silent congenital right-to-left extracardiac shunt, a persistent left superior vena cava draining into the left atrium. The patient's brain abscess was evacuated surgically and treated with antibiotics, and his shunt was subsequently repaired. The case suggests that attention should be paid to evaluation for shunt physiology allowing for bypass of the pulmonary circulation in those with recurrent brain abscesses.

8.
Plant Dis ; 106(9): 2355-2369, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35350902

RESUMO

Colletotrichum causing anthracnose in mango is known for its variable virulence that may have an effect on disease development and efficacy of management strategies. In this study, we characterized Colletotrichum spp. isolated from mango fruits under in vitro and in vivo conditions using close-range thermography and reflectance spectroscopy. Twenty-six isolates were phylogenetically characterized to ascertain species using the internal transcribed spacer sequence. Virulence, spectral (in vivo and in vitro), and thermographic responses (in vivo) of these isolates were analyzed. Isolates were grouped into the Colletotrichum gloeosporioides species complex and classified into eight morphotypes. Mycelial growth, conidia production, sporulation abundance, and area under disease progress curve (AUDPC) varied largely among isolates. Disease symptoms were observed 4 days after inoculation (dai), and, for most morphotypes, changes in tissue temperature were registered at 11 dai, with the greatest decrease at 14 dai with pathogen sporulation. In vitro and in vivo morphotypes shared changes in the spectrum range, and main variations were found in the number of informative spectral bands. In vivo average gross reflectance was higher in disease-inoculated tissue than in healthy uninoculated tissue. Morphotype responses varied depending on AUDPC values and postinoculation time. Discriminant analysis of the spectral response using principal component analysis and partial least squares regression explained 94 to 96.3 and 98 to 99.9% of the variance from in vitro and in vivo tests, respectively. Spectral markers were obtained for four distinct morphotype groups. We found three (550 to 650, 650.1 to 790, and 1,300 to 1,400 nm) and two (520 to 830 and 1,100 to 1,450 nm) regions with highly (P < 0.05) discriminant spectral bands for diseased fruits and morphotype characterization.


Assuntos
Colletotrichum , Mangifera , Colletotrichum/genética , Frutas , Filogenia , Doenças das Plantas , Análise Espectral , Termografia
9.
Microbiol Resour Announc ; 11(1): e0098021, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-34989603

RESUMO

We report a draft genome assembly of the causal agent of tomato vascular wilt, Fusarium oxysporum f. sp. lycopersici isolate 59, obtained from the Andean region in Colombia.

10.
Int J Mol Sci ; 22(22)2021 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-34830021

RESUMO

Original results are presented in the field of research that addresses the extension of the reaction of residue of acyl-thiosemicarbazide fixation on the structure of 5-nitrobenzimidazole by a sulphonic group. The aim of the study is the increase of new thiosemicarbazide derivatives' applicative potential in the field of biochemistry, with a wide range of medical applications. The newly obtained compounds were characterized by using elemental analysis and spectral analysis (FT-IR and 1H NMR). A study regarding the optimization of the chemical reactions was made. The performed in vitro biological tests confirmed the tuberculostatic activity of three newly obtained compounds against Mycobacterium tuberculosis.


Assuntos
Antituberculosos/síntese química , Mycobacterium tuberculosis/efeitos dos fármacos , Semicarbazidas/síntese química , Tuberculose/tratamento farmacológico , Antituberculosos/química , Antituberculosos/farmacologia , Humanos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/patogenicidade , Semicarbazidas/química , Semicarbazidas/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Relação Estrutura-Atividade , Tuberculose/microbiologia
11.
Healthcare (Basel) ; 9(1)2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33477942

RESUMO

BACKGROUND: The outbreak of the coronavirus disease 2019 (COVID-19) has led to significant changes in endoscopy units worldwide, with potential impact on patients' welfare as well as on endoscopy training. We aimed to assess the real-life impact of COVID-19 on the endoscopy unit in a tertiary care center from Romania. METHODS: A 6.5-month period during the COVID-19 pandemic was compared to a similar period from 2019. RESULTS: A 6.2-fold decrease of endoscopic procedures was noted. Colonoscopies were reduced from 916 to 42, p < 0.001; flexible sigmoidoscopies from 189 to 14, p = 0.009; upper gastrointestinal (GI) endoscopies from 2269 to 401, p = 0.006; and ERCP from 234 to 125, p < 0.001. The percentage of emergency procedures increased (38.8% vs. 26.2%, p < 0.001), as well as the rate of endoscopies performed for upper GI bleeding (42.5% vs. 24.4%, respectively, p < 0.001). The detection of cancers was considerably reduced (57 compared to 249, p = 0.001). There were fewer complications and higher success rates (7.6% vs. 19.2%, p < 0.001, and 94.2% vs. 90.7%, respectively). Fellows participation was also reduced from 90% to 40.9% (p < 0.001). CONCLUSIONS: The COVID-19 pandemic has significantly altered the workflow of the endoscopy unit, lowering the number of procedures performed and potentially compromising the early detection of cancers.

12.
Pathogens ; 9(1)2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31968574

RESUMO

In Colombia, tomato production under protected conditions represents an important economic contribution to the agricultural sector. Fusarium wilt diseases, caused by pathogenic formae speciales of the soil-borne fungus Fusarium oxysporum Schltdl., cause significant yield losses in tomatoes throughout the world. Investigation of the F. oxysporum-tomato pathosystem in Colombia is required to develop appropriate alternative disease management. In this study, 120 fungal isolates were obtained from four different departments in the Central Andean Region in Colombia from tomato crops with symptoms of wilt disease. A molecular characterization of the fungal isolates was performed using the SIX1, SIX3, and SIX4 effector genes of Fusarium oxysporum f. sp. lycopersici W.C. Snyder & H.N. Hansen (Fol). Additionally, we developed a new specific marker to distinguish between Fusarium oxysporum f. sp. radicis-lycopersici Jarvis & Shoemaker (Forl) and Fol isolates. Furthermore, a phylogenetic analysis using the Translation Elongation Factor 1-alpha (EF1a) gene was performed with the collected isolates. Two isolates (named Fol59 and Fol-UDC10) were identified as Fol race 2, four isolates were identified as Forl, six isolates were identified as F. solani, and most of the isolates were grouped within the F. oxysporum species complex. The phylogenetic tree of EF1a showed that most of the isolates could potentially correspond to nonpathogenic strains of F. oxysporum. Additional pathogenicity assays carried out with Fol59 and Fol-UDC10 confirmed that both isolates were highly virulent strains. This study represents a contribution to the understanding of the local interaction between tomatoes and F. oxysporum in Colombia.

13.
Front Microbiol ; 11: 593915, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33537009

RESUMO

The vascular wilt disease caused by the fungus Fusarium oxysporum f. sp. physali (Foph) is one of the most limiting factors for the production and export of cape gooseberry (Physalis peruviana) in Colombia. A transcriptomic analysis of a highly virulent strain of F. oxysporum in cape gooseberry plants, revealed the presence of secreted in the xylem (SIX) effector genes, known to be involved in the pathogenicity of other formae speciales (ff. spp.) of F. oxysporum. This pathogenic strain was classified as a new f. sp. named Foph, due to its specificity for cape gooseberry hosts. Here, we sequenced and assembled the genome of five strains of F. oxysporum from a fungal collection associated to the cape gooseberry crop (including Foph), focusing on the validation of the presence of SIX homologous and on the identification of putative effectors unique to Foph. By comparative and phylogenomic analyses based on single-copy orthologous, we found that Foph is closely related to F. oxysporum ff. spp., associated with solanaceous hosts. We confirmed the presence of highly identical homologous genomic regions between Foph and Fol that contain effector genes and identified six new putative effector genes, specific to Foph pathogenic strains. We also conducted a molecular characterization using this set of putative novel effectors in a panel of 36 additional stains of F. oxysporum including two of the four sequenced strains, from the fungal collection mentioned above. These results suggest the polyphyletic origin of Foph and the putative independent acquisition of new candidate effectors in different clades of related strains. The novel effector candidates identified in this genomic analysis, represent new sources involved in the interaction between Foph and cape gooseberry, that could be implemented to develop appropriate management strategies of the wilt disease caused by Foph in the cape gooseberry crop.

14.
BMC Cancer ; 18(1): 284, 2018 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-29534682

RESUMO

BACKGROUND: Smurf2 E3 ubiquitin ligase physically associates with and regulate the stability of distinct cellular protein substrates. The multi-functional scaffold protein Connector enhancer of kinase suppressor of ras 2 (CNKSR2) plays a key role in regulating cell proliferation, and differentiation through multiple receptor tyrosine kinase pathways. The aim of this study was to investigate whether the interaction between Smurf2 and CNKSR2 has any significant role in the post transcriptional regulation of CNKSR2 expression in breast cancer. METHODS: Here we demonstrate a novel interaction of CNKSR2 with Smurf2 by co-immunoprecipitation, indirect immunofluorescence studies, and surface plasmon resonance (SPR) analysis, which can ubiquitinate, but stabilize CNKSR2 by protecting it from proteasome mediated degradation. RESULTS: CNKSR2 protein levels were significantly increased upon forced overexpression of Smurf2, indicating the role of Smurf2 in regulating the stability of CNKSR2. Conversely, Smurf2 knockdown resulted in a marked decrease in the protein level expression of CNKSR2 by facilitating enhanced polyubiquitination and proteasomal degradation and reduced the proliferation and clonogenic survival of MDA-MB-231 breast cancer cell lines. Tissue microarray data from 84 patients with various stages of mammary carcinoma, including (in order of increasing malignant potential) normal, usual hyperplasia, fibrocystic changes, fibroadenoma, carcinoma-in-situ, and invasive ductal carcinoma showed a statistically significant association between Smurf2 and CNKSR2 expression, which is also well correlated with the ER, PR, and HER2 status of the tissue samples. A comparatively high expression of Smurf2 and CNKSR2 was observed when the expression of ER and PR was low, and HER2 was high. Consistently, both Smurf2 and CNKSR2 showed an integrated expression in MCF10 breast progression model cell lines. CONCLUSIONS: Altogether, our findings reveal that Smurf2 is a novel positive regulator of CNKSR2 and suggest that Smurf2-CNKSR2 interaction may serve as a common strategy to control proliferation of human breast cancer cells by modulating CNKSR2 protein stability.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/química , Neoplasias da Mama/patologia , Transformação Celular Neoplásica/patologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Neoplasias da Mama/metabolismo , Proliferação de Células , Transformação Celular Neoplásica/metabolismo , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Mapas de Interação de Proteínas , Processamento de Proteína Pós-Traducional , Estabilidade Proteica , Células Tumorais Cultivadas , Ubiquitinação
15.
BMC Complement Altern Med ; 17(1): 370, 2017 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-28720093

RESUMO

BACKGROUND: Solanum nigrum, herbal plant that commonly grows in temperate climate zone, has been used as a traditional folk medicine whose ripen fruits were proven to exhibit anti-tumor properties. In traditional Chinese medicine, it has been used for centuries to cure inflammation, edema, mastitis and hepatic cancer and in the Ayurvedic system of traditional medicine in India, S. nigrum is applied against enteric diseases, ulcer, diarrhea and skin diseases. A methanolic glycosidic extract fraction of unripe fruit of S. nigrum (SNME) was investigated for its anticancer property and possible mechanism to surmount adriamycin resistance in NCI/ADR-RES cells. METHODS: The NCI/ADR-RES cells were treated with 7.8125, 15.625, 31.25, 62.5, 125 and 250 µg/ml of methanolic extract of S. nigrum (SNME) for 12, 24 and 48 h, to check the cell viability and proliferation. The cells were also exposed to adriamycin alone or in combination with SNME and the effects on cell growth were determined by MTT. Cell cycle analysis, Ethidium bromide and Acridine orange staining, Annexin-binding efficiency, nuclear condensation and DNA fragmentation of the apoptotic NCI/ADR-RES cells were also determined. To elucidate the relationship between SNME and multi drug resistance, we analyzed the expression levels of Mdr-1, JAK1, STAT3, and pSTAT3 in NCI/ADR-RES cells after treatment with SNME. RESULTS: Results from the cytotoxicity assay showed a direct correlation between the concentration of methanolic glycosidic extract fraction of S. nigrum (SNME) and the surviving cell population. Combination with Adriamycin, SNME exhibits a synergistic action on NCI/ADR-RES cells, giving the first line of evidence to overcoming Adriamycin resistance. The SNME mediated cell growth suppression was proven to be apoptotic, based on results obtained from DNA fragmentation, annexin V apoptosis assaay and PARP cleavage analysis. Looking into the molecular insight SNME surpasses the chemoresistance of NCI/ADR-RES cells by inhibiting the JAK-STAT3 signaling pathway through the down regulation of JAK1, STAT3, pSTAT3, and Mdr1 expression. CONCLUSIONS: Collectively our findings suggest that unripe fruit of Solanum nigrum could possibly be used as a chemosensitizing agent against Adriamycin resistant cancers.


Assuntos
Doxorrubicina/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Neoplasias/metabolismo , Extratos Vegetais/farmacologia , Solanum nigrum , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/uso terapêutico , Linhagem Celular Tumoral , Regulação para Baixo , Doxorrubicina/uso terapêutico , Sinergismo Farmacológico , Frutas , Glicosídeos/farmacologia , Glicosídeos/uso terapêutico , Humanos , Janus Quinase 1/metabolismo , Medicina Tradicional , Neoplasias/tratamento farmacológico , Fitoterapia , Extratos Vegetais/uso terapêutico , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais
16.
Cell Div ; 9: 2, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25191523

RESUMO

BACKGROUND: Smurf2 is a member of the HECT family of E3 ubiquitin ligases that play important roles in determining the competence of cells to respond to TGF- ß/BMP signaling pathway. However, besides TGF-ß/BMP pathway, Smurf2 regulates a repertoire of other signaling pathways ranging from planar cell polarity during embryonic development to cell proliferation, migration, differentiation and senescence. Expression of Smurf2 is found to be dysregulated in many cancers including breast cancer. The purpose of the present study is to examine the effect of Smurf2 knockdown on the tumorigenic potential of human breast cancer cells emphasizing more on proliferative signaling pathway. METHODS: siRNAs targeting different regions of the Smurf2 mRNA were employed to knockdown the expression of Smurf2. The biological effects of synthetic siRNAs on human breast cancer cells were investigated by examining the cell proliferation, migration, invasion, focus formation, anchorage-independent growth, cell cycle arrest, and cell cycle and cell proliferation related protein expressions upon Smurf2 silencing. RESULTS: Smurf2 silencing in human breast cancer cells resulted in a decreased focus formation potential and clonogenicity as well as in vitro cell migration/invasion capabilities. Moreover, knockdown of Smurf2 suppressed cell proliferation. Cell cycle analysis showed that the anti-proliferative effect of Smurf2 siRNA was mediated by arresting cells in the G0/G1 phase, which was caused by decreased expression of cyclin D1and cdk4, followed by upregulation p21 and p27. Furthermore, we demonstrated that silencing of Smurf2 downregulated the proliferation of breast cancer cells by modulating the PI3K- PTEN-AKT-FoxO3a pathway via the scaffold protein CNKSR2 which is involved in RAS-dependent signaling pathways. The present study provides the first evidence that silencing Smurf2 using synthetic siRNAs can regulate the tumorigenic properties of human breast cancer cells in a CNKSR2 dependent manner. CONCLUSIONS: Our results therefore suggest a novel relation between Smurf2 and CNKSR2 thereby regulating AKT-dependent cell proliferation and invasion. Owing to the fact that PI3K-AKT signaling is hyperactivated in various human cancers and that Smurf2 also regulates cellular transformation, our results indicate that Smurf2 may serve as a potential molecule for targeted cancer therapy of certain tumour types including breast cancer.

17.
Biochim Biophys Acta ; 1835(1): 119-28, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23164545

RESUMO

Smad ubiquitin regulatory factors (Smurfs) belong to the HECT- family of E3 ubiquitin ligases and comprise mainly of two members, Smurf1 and Smurf2. Initially, Smurfs have been implicated in determining the competence of cells to respond to TGF-ß/BMP signaling pathway. Nevertheless, the intrinsic catalytic activity has extended the repertoire of Smurf substrates beyond the TGF-ß/BMP super family expanding its realm further to epigenetic modifications of histones governing the chromatin landscape. Through regulation of a large number of proteins in multiple cellular compartments, Smurfs regulate diverse cellular processes, including cell-cycle progression, cell proliferation, differentiation, DNA damage response, maintenance of genomic stability, and metastasis. As the genomic ablation of Smurfs leads to global changes in histone modifications and predisposition to a wide spectrum of tumors, Smurfs are also considered to have a novel tumor suppressor function. This review focuses on regulation network and biological functions of Smurfs in connection with its role in cancer progression. By providing a portrait of their protein targets, we intend to link the substrate specificity of Smurfs with their contribution to tumorigenesis. Since the regulation and biological functions of Smurfs are quite complex, understanding the oncogenic potential of these E3 ubiquitin ligases may facilitate the development of mechanism-based drugs in cancer treatment.


Assuntos
Transformação Celular Neoplásica/metabolismo , Neoplasias/enzimologia , Ubiquitina-Proteína Ligases/metabolismo , Humanos
18.
J Exp Clin Cancer Res ; 30: 56, 2011 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-21575192

RESUMO

BACKGROUND: Signal transducer and activator of transcription 3 (STAT3) is a key signaling molecule and a central cytoplasmic transcription factor, implicated in the regulation of growth. Its aberrant activation has been demonstrated to correlate with many types of human malignancy. However, whether constitutive STAT3 signaling plays a key role in the survival and growth of soft-tissue tumors is still unclear and hence needs to be elucidated further. In our study we examined the expression levels of STAT3 and pSTAT3 in different grades of soft tissue tumors and correlated with its clinicopathological characteristics. METHODS: Expression levels of STAT3 and pSTAT3 in soft tissue tumors were studied using Immunohistochemistry, Western blotting and Reverse transcriptase- PCR and correlated with its clinicopathological characteristics using Chi squared or Fisher's exact test and by logistic regression analysis. Statistical analysis was done using Intercooled Stata software (Intercooled Stata 8.2 version). RESULTS: Of the 82 soft tissue tumor samples, fifty four (65.8%) showed immunoreactivity for STAT3 and twenty eight (34.1%) for pSTAT3. Expression of STAT3 and pSTAT3 was significantly associated with tumor grade (P < 0.001; P < 0.001), tumor location (P = 0.025; P = 0.027), plane of tumor (P = 0.011; P = 0.006), and tumor necrosis (P = 0.001; P = 0.002). Western blotting and RT-PCR analysis showed increased expression of STAT3 and p-STAT3 as grade of malignancy increased. CONCLUSION: These findings suggest that constitutive activation of STAT3 is an important factor related to carcinogenesis of human soft tissue tumors and is significantly associated with its clinicopathological parameters which may possibly have potential diagnostic implications.


Assuntos
Regulação Neoplásica da Expressão Gênica , Fator de Transcrição STAT3/metabolismo , Neoplasias de Tecidos Moles/fisiopatologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Fosforilação , Prognóstico , RNA Mensageiro/metabolismo , Fator de Transcrição STAT3/genética , Neoplasias de Tecidos Moles/diagnóstico , Adulto Jovem
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