Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
Cureus ; 16(4): e59049, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38800335

RESUMO

Introduction Lymphadenopathy, characterized by the enlargement of lymph nodes, is a common concern encountered by physicians in outpatient settings. It is deemed significant and warrants evaluation due to the diverse range of potential causes, ranging from treatable infections to incurable metastatic malignancies. Fine needle aspiration cytology (FNAC) emerges as a crucial tool in addressing these concerns, acknowledged for its rapid diagnostic capabilities, simplicity, accuracy, and minimal invasiveness. Objectives This retrospective study aims to characterize the spectrum of lymphadenopathy cases observed in a tertiary care center over a specified period, shedding light on the prevalence, etiology, and clinical outcomes associated with this condition. Methods Electronic medical records of patients presenting with lymphadenopathy to the tertiary care center between May 2021 and June 2023 were reviewed. Data on patient demographics, clinical presentation, imaging findings, and cytopathological and histopathological diagnoses were analyzed. Results A total of 300 cases of lymphadenopathy were identified during the study period. The study population exhibited a diverse range of age groups, with a slight predilection for the age range of 11-20 years. The most common sites of lymphadenopathy were in the cervical group, and the predominant clinical presentations included tender lymph nodes and fever. Etiologically, infectious causes, such as accounted for the majority of cases, followed by inflammatory and neoplastic etiologies. Notably, 2.6 % of cases presented with non-specific lymphadenopathy, warranting further investigation. Diagnostic modalities, including imaging studies and histopathological examinations, played a crucial role in establishing accurate diagnoses. The study also highlights the challenges in differentiating benign from malignant lymphadenopathy, emphasizing the need for a comprehensive diagnostic approach. Conclusion This study provides a comprehensive overview of the lymphadenopathy spectrum in a tertiary care center, emphasizing the importance of a multidisciplinary approach for accurate diagnosis and management. The findings contribute to our understanding of the epidemiology and etiological patterns of lymphadenopathy, guiding clinicians in optimizing patient care and outcomes in a tertiary healthcare setting.

2.
ACS Chem Neurosci ; 15(6): 1254-1264, 2024 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-38436259

RESUMO

The reactivation of ubiquitously present Epstein-Barr virus (EBV) is known to be involved with numerous diseases, including neurological ailments. A recent in vitro study from our group unveiled the association of EBV and its 12-amino acid peptide glycoprotein M146-157 (gM146-157) with neurodegenerative diseases, viz., Alzheimer's disease (AD) and multiple sclerosis. In this study, we have further validated this association at the in vivo level. The exposure of EBV/gM146-157 to mice causes a decline in the cognitive ability with a concomitant increase in anxiety-like symptoms through behavioral assays. Disorganization of hippocampal neurons, cell shrinkage, pyknosis, and apoptotic appendages were observed in the brains of infected mice. Inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were found to be elevated in infected mouse brain tissue samples, whereas TNF-α exhibited a decline in the serum of these mice. Further, the altered levels of nuclear factor-kappa B (NF-kB) and neurotensin receptor 2 affirmed neuroinflammation in infected mouse brain samples. Similarly, the risk factor of AD, apolipoprotein E4 (ApoE4), was also found to be elevated at the protein level in EBV/gM146-157 challenged mice. Furthermore, we also observed an increased level of myelin basic protein in the brain cortex. Altogether, our results suggested an integral connection of EBV and its gM146-157 peptide to the neuropathologies.


Assuntos
Infecções por Vírus Epstein-Barr , Herpesvirus Humano 4 , Animais , Camundongos , Herpesvirus Humano 4/metabolismo , Infecções por Vírus Epstein-Barr/patologia , Fator de Necrose Tumoral alfa/metabolismo , Citocinas , Glicoproteínas
3.
J Pathol ; 262(1): 105-120, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37850574

RESUMO

HOXB13 is a key lineage homeobox transcription factor that plays a critical role in the differentiation of the prostate gland. Several studies have suggested that HOXB13 alterations may be involved in prostate cancer development and progression. Despite its potential biological relevance, little is known about the expression of HOXB13 across the disease spectrum of prostate cancer. To this end, we validated a HOXB13 antibody using genetic controls and investigated HOXB13 protein expression in murine and human developing prostates, localized prostate cancers, and metastatic castration-resistant prostate cancers. We observed that HOXB13 expression increases during later stages of murine prostate development. All localized prostate cancers showed HOXB13 protein expression. Interestingly, lower HOXB13 expression levels were observed in higher-grade tumors, although no significant association between HOXB13 expression and recurrence or disease-specific survival was found. In advanced metastatic prostate cancers, HOXB13 expression was retained in the majority of tumors. While we observed lower levels of HOXB13 protein and mRNA levels in tumors with evidence of lineage plasticity, 84% of androgen receptor-negative castration-resistant prostate cancers and neuroendocrine prostate cancers (NEPCs) retained detectable levels of HOXB13. Notably, the reduced expression observed in NEPCs was associated with a gain of HOXB13 gene body CpG methylation. In comparison to the commonly used prostate lineage marker NKX3.1, HOXB13 showed greater sensitivity in detecting advanced metastatic prostate cancers. Additionally, in a cohort of 837 patients, 383 with prostatic and 454 with non-prostatic tumors, we found that HOXB13 immunohistochemistry had a 97% sensitivity and 99% specificity for prostatic origin. Taken together, our studies provide valuable insight into the expression pattern of HOXB13 during prostate development and cancer progression. Furthermore, our findings support the utility of HOXB13 as a diagnostic biomarker for prostate cancer, particularly to confirm the prostatic origin of advanced metastatic castration-resistant tumors. © 2023 The Pathological Society of Great Britain and Ireland.


Assuntos
Neoplasias de Próstata Resistentes à Castração , Neoplasias da Próstata , Animais , Humanos , Masculino , Camundongos , Genes Homeobox , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Próstata/patologia , Neoplasias da Próstata/patologia , Neoplasias de Próstata Resistentes à Castração/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Reino Unido
4.
BJOG ; 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37973605

RESUMO

OBJECTIVE: Evaluation of hysteroscopic and laparoscopic findings in subfertile women predictive of tuberculosis. DESIGN: Retrospective case series analysis. SETTING: Tertiary hospital in India. POPULATION: A retrospective analysis of 16 784 subfertile women who had undergone diagnostic hysterolaparoscopy (DHL) was conducted between February 2014 and June 2021. METHODS: Histopathological evidence, acid-fast bacilli (AFB), culture and GeneXpert MTB/RIF assay were used to diagnose female genital tuberculosis (FGTB). Various hysteroscopic and laparoscopic findings were analysed, and a binary logistic regression assessed associations between these findings and positive diagnostic outcomes. MAIN OUTCOME MEASURES: Various hysteroscopic and laparoscopic findings correspond to tubercular manifestation. RESULTS: Of the 16,784 patients, 1083 had hysteroscopy and laparoscopy findings suggestive of tuberculosis, and 309 were diagnosed with FGTB based on diagnostic tests. Logistic regression identified variables strongly predictive of positive status outcomes; tuberculous abdomino-pelvic adhesions of various grades, isthmo-ampullary block, tubercle, tubo-ovarian mass, tuberculous hydrosalpinx, complete tubal destruction, tubal diverticula and rigid tube emerged as strong predictors. CONCLUSIONS: Logistic regression-derived predictors, alongside specific laparoscopic and hysteroscopic findings, can enhance diagnostic accuracy and clinical decision-making to start antitubercular therapy in subfertile women.

5.
Cureus ; 15(9): e44545, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37790038

RESUMO

A rare inflammatory breast disorder called lymphocytic mastitis is characterized by lymphocyte infiltrates in the mammary parenchyma. Due to their rarity, incidental observations of invasive ductal carcinoma in lymphocytic mastitis present diagnostic and management challenges. We present a case of a 52-year-old female with a history of painfully swollen breasts for three months who underwent a core needle biopsy, consistent with lymphocytic mastitis on histopathology. Due to persistent and worsening symptoms, a mastectomy was performed. During the examination, an incidental finding of infiltrating ductal carcinoma was identified in the mastectomy specimen. This unexpected discovery led to further investigations and altered the patient's treatment plan. The detection of invasive ductal carcinoma in the presence of lymphocytic mastitis highlights the importance of continuous surveillance and thorough examination. In the circumstances of lymphocytic mastitis, it is vital to take the likelihood of concurrent malignancy into account, especially when symptoms persist or reappear after appropriate management. This case report seeks to raise awareness among physicians of this exceptional association and drive further research that will explain its pathophysiology while enhancing management strategies.

6.
Cureus ; 15(12): e49880, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38174205

RESUMO

Liquid biopsy is a new diagnostic tool in precision oncology that can be used as a complementary or alternative method to surgical biopsies. It is a cutting-edge sampling technique that examines distinct cancer components, such as exosomes and circulating tumor cells discharged into the peripheral circulation, to identify tumor biomarkers through various methods, including polymerase chain reaction (PCR). Liquid biopsy has several benefits, including its non-invasiveness and practicality, which permit serial sampling and long-term monitoring of dynamic tumor changes. Ovarian cancer (OC), the most lethal gynecologic malignancy in the world, is typically diagnosed at stages II and III, which makes recovery and treatment extremely difficult. Relapsed OC and chemotherapy resistance of ovarian tumor cells are other clinical challenges. Although liquid biopsy is not a routinely used diagnostic test, it should be utilized in the diagnosis and prognosis of OC for early detection and treatment. It is less intrusive than conventional tissue biopsies, allowing for the continuous collection of serial blood samples to track cancer development in real time. Before therapeutic application, more investigation is required to pinpoint the particular release processes, the source tissue, and the biological significance of the bulk of liquid biopsy contents.

7.
Cancers (Basel) ; 14(24)2022 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-36551505

RESUMO

The mainstay treatment for locally advanced, recurrent, or metastatic prostate cancer (PrCa) is androgen deprivation therapy (ADT). ADT causes prostate cancers to shrink in volume, or regress, by inducing epithelial tumor cell apoptosis. In normal, non-neoplastic murine prostate, androgen deprivation via castration induces prostate gland regression that is dependent on TNF signaling. In addition to this direct mechanism of action, castration has also been implicated in an indirect mechanism of prostate epithelial cell death, which has been described as vascular regression. The initiating event is endothelial cell apoptosis and/or increased vascular permeability. This subsequently leads to reduced blood flow and perfusion, and then hypoxia, which may enhance epithelial cell apoptosis. Castration-induced vascular regression has been observed in both normal and neoplastic prostates. We used photoacoustic, power Doppler, and contrast-enhanced ultrasound imaging, and CD31 immunohistochemical staining of the microvasculature to assess vascular integrity in the period immediately following castration, enabling us to test the role of TNF signaling in vascular regression. In two mouse models of androgen-responsive prostate cancer, TNF signaling blockade using a soluble TNFR2 ligand trap reversed the functional aspects of vascular regression as well as structural changes in the microvasculature, including reduced vessel wall thickness, cross-sectional area, and vessel perimeter length. These results demonstrate that TNF signaling is required for vascular regression, most likely by inducing endothelial cell apoptosis and increasing vessel permeability. Since TNF is also the critical death receptor ligand for prostate epithelial cells, we propose that TNF is a multi-purpose, comprehensive signal within the prostate cancer microenvironment that mediates prostate cancer regression following androgen deprivation.

8.
Cell Div ; 17(1): 6, 2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36494865

RESUMO

Molecular epidemiology evidence indicates racial and ethnic differences in the aggressiveness and survival of breast cancer. Hispanics/Latinas (H/Ls) and non-Hispanic Black women (NHB) are at higher risk of breast cancer (BC)-related death relative to non-Hispanic white (NHW) women in part because they are diagnosed with hormone receptor-negative (HR) subtype and at higher stages. Since the cell cycle is one of the most commonly deregulated cellular processes in cancer, we propose that the mitotic kinases TTK (or Mps1), TBK1, and Nek2 could be novel targets to prevent breast cancer progression among NHBs and H/Ls. In this study, we calculated levels of TTK, p-TBK1, epithelial (E-cadherin), mesenchymal (Vimentin), and proliferation (Ki67) markers through immunohistochemical (IHC) staining of breast cancer tissue microarrays (TMAs) that includes samples from 6 regions in the Southeast of the United States and Puerto Rico -regions enriched with NHB and H/L breast cancer patients. IHC analysis showed that TTK, Ki67, and Vimentin were significantly expressed in triple-negative (TNBC) tumors relative to other subtypes, while E-cadherin showed decreased expression. TTK correlated with all of the clinical variables but p-TBK1 did not correlate with any of them. TCGA analysis revealed that the mRNA levels of multiple mitotic kinases, including TTK, Nek2, Plk1, Bub1, and Aurora kinases A and B, and transcription factors that are known to control the expression of these kinases (e.g. FoxM1 and E2F1-3) were upregulated in NHBs versus NHWs and correlated with higher aneuploidy indexes in NHB, suggesting that these mitotic kinases may be future novel targets for breast cancer treatment in NHB women.

9.
Artigo em Inglês | MEDLINE | ID: mdl-36374840

RESUMO

Colorectal cancer (CRC) is the second most common cause of cancer related deaths in the United States. However, more than half of all incidence and mortality are caused by risk factors such as smoking, unhealthy diet, excessive alcohol consumption, inactivity, and excess weight, and thus can be protected. CRC morbidity and mortality can also be reduced by proper screening and monitoring. Over the last few years the amalgamation of nanotechnology with healthcare system has brought about the potential to administer the delivery of certain therapeutic drugs to cancer cells without affecting normal tissues. Recent strategies combine the diagnostic and therapeutic approaches to improve the overall performance of cancer nanomedicines. Targeted cancer nanotherapeutics provides many more opportunities for the selective detection of toxic chemicals within cancer cells. The distinctive features of nanoparticles, such as their small size, large surface to volume ratio, and the ability of nanoparticles to achieve several interactions of ligands at surface, offer great benefits of nanomedicines to treat various types of cancers. This review highlights the molecular mechanisms of colorectal carcinogenesis and discusses various key concepts in the development of nanotherapeutics targeted for CRC treatment.


Assuntos
Neoplasias Colorretais , Nanopartículas , Humanos , Sistemas de Liberação de Medicamentos , Nanomedicina , Nanopartículas/química , Nanotecnologia , Neoplasias Colorretais/tratamento farmacológico
10.
Carcinogenesis ; 43(10): 988-1001, 2022 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-35738876

RESUMO

The transforming properties of the high-risk human papillomavirus (HPV) E7 oncoprotein are indispensable for driving the virus life cycle and pathogenesis. Besides inactivation of the retinoblastoma family of tumor suppressors as part of its oncogenic endeavors, E7-mediated perturbations of eminent cell cycle regulators, checkpoint proteins and proto-oncogenes are considered to be the tricks of its transformative traits. However, many such critical interactions are still unknown. In the present study, we have identified the anaphase-promoting complex/cyclosome (APC) co-activator, Cdh1, as a novel interacting partner and a degradation target of E7. We found that HPV16 E7-induced inactivation of Cdh1 promoted abnormal accumulation of multiple Cdh1 substrates. Such a mode of deregulation possibly contributes to HPV-mediated cervical oncogenesis. Our mapping studies recognized the C-terminal zinc-finger motif of E7 to associate with Cdh1 and interfere with the timely degradation of FoxM1, a bona fide Cdh1 substrate and a potent oncogene. Importantly, the E7 mutant with impaired interaction with Cdh1 exhibited defects in its ability for overriding typical cell cycle transition and oncogenic transformation, thereby validating the functional and pathological significance of the E7-Cdh1 axis during cervical carcinoma progression. Altogether, the findings from our study discover a unique nexus between E7 and APC/C-Cdh1, thereby adding to our understanding of the mechanism of E7-induced carcinogenesis and provide a promising target for the management of cervical carcinoma.


Assuntos
Carcinoma , Infecções por Papillomavirus , Neoplasias do Colo do Útero , Feminino , Humanos , Ciclossomo-Complexo Promotor de Anáfase/genética , Ciclossomo-Complexo Promotor de Anáfase/metabolismo , Anáfase , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/metabolismo , Papillomavirus Humano 16 , Carcinogênese/genética , Neoplasias do Colo do Útero/metabolismo , Proteínas de Ciclo Celular/metabolismo , Antígenos CD/genética , Antígenos CD/metabolismo , Caderinas/genética , Caderinas/metabolismo
11.
Drug Res (Stuttg) ; 69(6): 305-313, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30517965

RESUMO

Genistein is the natural isoflavone and a phytoestrogen with a broad range of pharmacological properties, such as tyrosine and topoisomerase inhibition. It also induces apoptosis and cell proliferation inhibition, differentiates cancer cells. Added health benefits include the reduction of osteoporosis by suppressing osteoclasts and lymphocyte functions, decreased the risk of cardiovascular attacks and relieved postmenopausal problems. Genistein traditionally used in Chinese and Ayurvedic medicine and are found to be associated with lower risk of breast, prostate and lung cancer. Numerous factors comprising genetic, epigenetic and transcriptomic alterations are evidenced to be responsible for breast, prostate and lung cancer. In present review, an overview on genistein, the various analytical methods and drug delivery approaches to determine genistein in the formulations are discussed. It may help to develop novel formulations with better solubility and bioavailability of genistein. The tumor cell scan may be targeted to form a stable genistein formulation.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Genisteína/farmacologia , Neoplasias/tratamento farmacológico , Fitoestrógenos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Disponibilidade Biológica , Genisteína/uso terapêutico , Humanos , Ayurveda/métodos , Medicina Tradicional Chinesa/métodos , Fitoestrógenos/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Solubilidade
12.
Semin Cancer Biol ; 52(Pt 1): 74-84, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-28855104

RESUMO

The past few decades have witnessed a tremendous progress in understanding the biology of cancer, which has led to more comprehensive approaches for global gene expression profiling and genome-wide analysis. This has helped to determine more sophisticated prognostic and predictive signature markers for the prompt diagnosis and precise screening of cancer patients. In the search for novel biomarkers, there has been increased interest in FoxM1, an extensively studied transcription factor that encompasses most of the hallmarks of malignancy. Considering the attractive potential of this multifarious oncogene, FoxM1 has emerged as an important molecule implicated in initiation, development and progression of cancer. Bolstered with the skill to maneuver the proliferation signals, FoxM1 bestows resistance to contemporary anti-cancer therapy as well. This review sheds light on the large body of literature that has accumulated in recent years that implies that FoxM1 neoplastic functions can be used as a novel predictive, prognostic and therapeutic marker for different cancers. This assessment also highlights the key features of FoxM1 that can be effectively harnessed to establish FoxM1 as a strong biomarker in diagnosis and treatment of cancer.


Assuntos
Biomarcadores Tumorais/genética , Proteína Forkhead Box M1/genética , Neoplasias/genética , Oncogenes/genética , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Neoplasias/diagnóstico , Neoplasias/terapia , Prognóstico
13.
FEBS Lett ; 591(21): 3507-3522, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28948618

RESUMO

Cytoglobin (Cygb) is a cellular haemoprotein belonging to the globin family with ambiguous biological functions. Downregulation of Cygb in many cancers is indicative of its tumour-suppressive role. This is the first report showing the cell cycle regulation of Cygb, which was found to peak at G1 and rapidly decline in S phase. Importantly, Skp2-mediated degradation of Cygb was identified as the key mechanism for controlling its oscillating levels during the cell cycle. Moreover, overexpression of Cygb stimulates hypophosphorylation of Rb causing delayed cell cycle progression. Overall, the study reveals a novel mechanism for the regulated expression of Cygb and also assigns a new role to Cygb in cell cycle control.


Assuntos
Fase G1/fisiologia , Globinas/metabolismo , Proteólise , Fase S/fisiologia , Proteínas Quinases Associadas a Fase S/metabolismo , Ciclo Celular , Citoglobina , Células HEK293 , Humanos , Fosforilação/fisiologia , Proteína do Retinoblastoma/metabolismo
14.
Biochemistry ; 55(49): 6832-6847, 2016 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-27951646

RESUMO

Since its discovery, neuroglobin (Ngb), a neuron-specific oxygen binding hemoglobin, distinct from the classical myoglobin and blood hemoglobin, has attracted attention as an endogenous neuroprotectant. Recent reports suggest that Ngb protects neurons from brain stroke, ischemic stress-induced degeneration, and other brain disorders. Proteins with a specific role in neuroprotection are often associated with neurodegeneration, as well, depending on the cellular environment or specific cellular triggers that tilt the balance one way or the other. This investigation explored the potential role of Ngb in amyloid fibril-related neuronal disorder. Ngb was capable of amyloid formation in vitro at neutral pH and ambient temperature, in both apo and holo forms, albeit at a slower rate in the holo form, unlike other hemoglobins that exhibit such behavior exclusively in the apo states. Elevated temperature enhanced the rate of fibril formation significantly. The B-helix, which is known to play a major role in Ngb ligand binding kinetics, was found to be amyloidogenic with the Phe28B10 amino acid side chain as the key inducer of fibrillation. The Ngb amyloid fibril was also significantly cytotoxic to neuroblastoma cell lines, compared to those obtained from reference hemoglobins. The Ngb fibril probably promoted toxicity by inducing channel formation in the cell membrane, as investigated here using synthetic lipid bilayer membranes and the propidium iodide uptake assay. These findings imply that Ngb plays a role in neurodegenerative disorders in vivo, for which there seems to be indirect evidence by association. Ngb thus presents a novel prospect for understanding amyloid-related brain disorders beyond the limited set of proteins currently investigated for such diseases.


Assuntos
Amiloide/química , Encéfalo/metabolismo , Globinas/química , Hemoglobinas/química , Proteínas do Tecido Nervoso/química , Fenilalanina/química , Linhagem Celular Tumoral , Dicroísmo Circular , Globinas/genética , Humanos , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Transmissão , Mutagênese Sítio-Dirigida , Proteínas do Tecido Nervoso/genética , Neuroglobina , Temperatura
15.
Int J Biochem Cell Biol ; 58: 28-36, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25462159

RESUMO

The oncogenic transcription factor Forkhead box M1b (FoxM1b), a key regulator of cell cycle, is often overexpressed in many human cancers. Interestingly, posttranslational modifications are known to play important role in regulating the levels and activity of FoxM1b. The purpose of the present study was to characterize the SUMOylation of FoxM1b and identify the functional consequences including viral pathogenesis. Here, we report that FoxM1b interacts with SUMOylating enzymes Ubc9 and PIAS1 and acts as a substrate for SUMOylation. We also show that SUMOylation facilitates FoxM1b protein destabilization and nucleocytoplasmic shuttling. More importantly, we provide the first evidence for a role of E7 oncoprotein in high risk human papillomavirus (HPV) mediated upregulation of FoxM1b. The elevated expression of FoxM1 was determined to be posttranscriptional and was attributed to decreased SUMOylation of FoxM1b in the E7-expressing cells. Moreover, we demonstrate the involvement of SUMOylation in regulation of FoxM1 and present biochemical evidence that HPV16 E7 oncoprotein can modulate SUMOylation of FoxM1b by impairing its interaction with Ubc9. Together, these results provide a novel connection between SUMOylation of FoxM1b and HPV carcinogenesis. The findings may have important implications in the discovery of future anti-cancer therapeutics.


Assuntos
Fatores de Transcrição Forkhead/metabolismo , Proteínas E7 de Papillomavirus/genética , Western Blotting , Linhagem Celular , Linhagem Celular Tumoral , Feminino , Proteína Forkhead Box M1 , Fatores de Transcrição Forkhead/genética , Células HeLa , Humanos , Imunoprecipitação , Sumoilação/genética , Enzimas de Conjugação de Ubiquitina/genética , Enzimas de Conjugação de Ubiquitina/metabolismo , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/metabolismo
16.
DNA Repair (Amst) ; 24: 107-112, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25269893

RESUMO

Cytoglobin (Cygb) is an emerging tumor suppressor gene silenced by promoter hypermethylation in many human tumors. So far, the precise molecular mechanism underlying its tumor suppressive function remains poorly understood. Here, we identified Cygb as a genotoxic stress-responsive hemoprotein upregulated upon sensing cellular DNA damage. Our studies demonstrated that Cygb physically associates with and stabilizes p53, a key cellular DNA damage signaling factor. We provide evidence that Cygb extends the half-life of p53 by blocking its ubiquitination and subsequent degradation. We show that, upon DNA damage, cells overexpressing Cygb displayed proliferation defect by rapid accumulation of p53 and its target gene p21, while Cygb knockdown cells failed to efficiently arrest in G1 phase in response to DNA insult. These results suggest a possible involvement of Cygb in mediating cellular response to DNA damage and thereby contributing in the maintenance of genomic integrity. Our study thus presents a novel insight into the mechanistic role of Cygb in tumor suppression.


Assuntos
Dano ao DNA , Pontos de Checagem da Fase G1 do Ciclo Celular , Globinas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Citoglobina , Dano ao DNA/efeitos dos fármacos , Doxorrubicina/farmacologia , Etoposídeo/farmacologia , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Globinas/genética , Células HEK293/efeitos dos fármacos , Humanos , Estabilidade Proteica , Proteína Supressora de Tumor p53/genética , Ubiquitinação
17.
Carcinogenesis ; 35(8): 1830-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24795430

RESUMO

Despite significant research, our understanding of the molecular mechanisms of Human Papilloma Virus (HPV) induced cancers remains incomplete. Majority of invasive cervical cancers are caused by high-risk HPV 16 and 18. Two potent HPV oncoproteins, E6 and E7, promote human malignancies by disrupting the activities of key regulators of cell proliferation and apoptosis. Recent investigations have identified hADA3, a transcriptional coactivator protein as a target of high-risk HPV16E6. However, the mechanism of degradation of hADA3 by E6 and its contribution in HPV induced carcinogenesis is poorly understood. Here, we showed that E6-mediated proteolysis of hADA3 is responsible for maintaining low levels of hADA3 in HPV-positive cervical cancer cell lines. We demonstrate that HPV16E6 targets hADA3 for ubiquitin-mediated degradation via E6AP ubiquitin ligase. We also show that hADA3 undergoes accelerated SUMOylation in the presence of HPV16E6. Our data represent the first evidence that hADA3 is posttranslationally modified by SUMOylation, which makes it unstable and establishes a link between SUMOylation and E6-mediated ubiquitination of hADA3. Furthermore, depletion of Ubc9 prevented rapid degradation of hADA3 in E6 expressing cervical cancer cells and overexpression of hADA3 resulted in suppression of proliferation and migration abilities of SiHa cells. Overall, this study underscores the importance of posttranslational modifications in HPV16E6-mediated downregulation of hADA3 thereby unveiling a novel mechanism by which HPV induces oncogenesis.


Assuntos
Papillomavirus Humano 16/fisiologia , Proteínas Oncogênicas Virais/metabolismo , Infecções por Papillomavirus/metabolismo , Proteínas Repressoras/metabolismo , Sumoilação , Fatores de Transcrição/metabolismo , Neoplasias do Colo do Útero/metabolismo , Western Blotting , Proliferação de Células , Feminino , Humanos , Imunoprecipitação , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Proteólise , Fatores de Risco , Células Tumorais Cultivadas , Ubiquitinação , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , Cicatrização
18.
Neurol Res ; 36(12): 1072-9, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24861496

RESUMO

OBJECTIVES: The goals of this study were: (1) to obtain basic information about the effects of long-term use of mobile phones on cytological makeup of the hippocampus in rat brains (2) to evaluate the effects on antioxidant status, and (3) to evaluate the effects on cognitive behavior particularly on learning and memory. METHODS: Rats (age 30 days, 120 ± 5 g) were exposed to 900 MHz radio waves by means of a mobile hand set for 4 hours per day for 15 days. Effects on anxiety, spatial learning, and memory were studied using the open field test, the elevated plus maze, the Morris water maze (MWM), and the classic maze test. Effects on brain antioxidant status were also studied. Cresyl violet staining was done to assess the neuronal damage. RESULT: A significant change in behavior, i.e., more anxiety and poor learning was shown by test animals as compared to controls and sham group. A significant change in the level of antioxidant enzymes and non-enzymatic antioxidants, and an increase in lipid peroxidation were observed in the test rats. Histological examination showed neurodegenerative cells in hippocampal sub regions and the cerebral cortex. DISCUSSION: Thus our findings indicate extensive neurodegeneration on exposure to radio waves. Increased production of reactive oxygen species due to exhaustion of enzymatic and non-enzymatic antioxidants and increased lipid peroxidation indicate extensive neurodegeneration in selective areas of CA1, CA3, DG, and the cerebral cortex. This extensive neuronal damage results in alterations in behavior related to memory and learning.


Assuntos
Comportamento Animal/efeitos da radiação , Hipocampo/metabolismo , Hipocampo/patologia , Micro-Ondas/efeitos adversos , Animais , Ansiedade , Telefone Celular , Masculino , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio , Aprendizagem Espacial/efeitos da radiação , Memória Espacial/efeitos da radiação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA