RESUMEN
Nucleophosmin (NPM1) is a nucleolar protein that is frequently overexpressed in various types of solid tumors. NPM1 is involved in several cellular processes that might contribute significantly to the increased proliferation potential of cancers. Previous reports suggest that NPM1 expression is highly increased in response to mitogenic and oncogenic signals, the mechanisms of which have not been elucidated extensively. Using constructs incorporating different fragments of the NPM1 promoter upstream to a Luciferase reporter gene, we have identified the minimal promoter of NPM1 and candidate transcription factors regulating NPM1 promoter activity by luciferase reporter assays. We have validated the roles of a few candidate factors at the transcriptional and protein level by quantitative reverse transcriptase PCR, immunoblotting and immunohistochemistry, and explored the mechanism of regulation of NPM1 expression using immunoprecipitation and chromatin immunoprecipitation assays. We show here that the expression of NPM1 is regulated by transcription factor c-fos, a protein that is strongly activated by growth factor signals. In addition, mutant p53 (R175H) overexpression also enhances NPM1 expression possibly through c-myc and c-fos. Moreover, both c-fos and mutant p53 are overexpressed in oral tumor tissues that showed NPM1 overexpression. Collectively, our results suggest that c-fos and mutant p53 R175H positively regulate NPM1 expression, possibly in synergism, that might lead to oncogenic manifestation.
Asunto(s)
Carcinoma de Células Escamosas/patología , Regulación Neoplásica de la Expresión Génica , Genes fos , Neoplasias de la Boca/patología , Mutación , Proteínas Nucleares/genética , Proteína p53 Supresora de Tumor/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Proliferación Celular , Humanos , Neoplasias de la Boca/genética , Neoplasias de la Boca/metabolismo , Proteínas Nucleares/metabolismo , Nucleofosmina , Pronóstico , Regiones Promotoras Genéticas , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/genéticaRESUMEN
BACKGROUND: p300 (KAT3B) lysine acetyltransferase activity is modulated under different physiological and pathological contexts through the induction of trans-autoacetylation. This phenomenon is mediated by several factors, mechanisms of which are not fully understood. METHODS: Through acetyltransferase assays using full-length, baculovirus-expressed KATs, the specificity of NPM1-mediated enhancement of p300 autoacetylation was tested. Chaperone assays and tryptophan fluorescence studies were performed to evaluate the NPM1-induced protein folding. The NPM1 oligomer-defective mutant characterization was done by glutaraldehyde-crosslinking. The small-molecule inhibitor of NPM1 oligomerization was used to confirm the absolute requirement of multimeric NPM1 in vivo. Immunohistochemistry analysis of oral cancer patient samples was done to uncover the pathophysiological significance of NPM1-induced p300 autoacetylation. RESULTS: We find that the histone chaperone NPM1 is a specific inducer of p300 autoacetylation. Distinct from its histone chaperone activity, NPM1 is a molecular chaperone of p300. The biophysical experiments suggest that there is a reversible binding between NPM1 and p300 which can modulate p300 acetyltransferase activity. Disruption of NPM1 oligomerization suggests that oligomeric NPM1 is essential for the induction of p300 autoacetylation. Significantly, we observe a concomitant hyper-autoacetylation of p300 with overexpression of NPM1 in oral cancer samples. CONCLUSION: NPM1 can specifically modulate p300 acetyltransferase activity through the enhancement of autoacetylation. The molecular chaperone activity and oligomerization of NPM1 play a pivotal role in this phenomenon. GENERAL SIGNIFICANCE: NPM1 is overexpressed in several solid cancers, the significance of which is unknown. Induction of p300 autoacetylation could be the cause of NPM1-mediated tumorigenicity.
Asunto(s)
Proteína p300 Asociada a E1A/química , Proteína p300 Asociada a E1A/metabolismo , Histonas/metabolismo , Proteínas Nucleares/química , Proteínas Nucleares/metabolismo , Pliegue de Proteína , Multimerización de Proteína , Neoplasias de la Lengua/metabolismo , Acetilación , Humanos , Nucleofosmina , Unión Proteica , Conformación Proteica , Neoplasias de la Lengua/patología , Células Tumorales CultivadasRESUMEN
AIMS: The aim of this study is to compare the effects of yoga program with supportive therapy counseling on mood states, treatment-related symptoms, toxicity, and quality of life in Stage II and III breast cancer patients on conventional treatment. METHODS: Ninety-eight Stage II and III breast cancer patients underwent surgery followed by adjuvant radiotherapy (RT) or chemotherapy (CT) or both at a cancer center were randomly assigned to receive yoga (n = 45) and supportive therapy counseling (n = 53) over a 24-week period. Intervention consisted of 60-min yoga sessions, daily while the control group was imparted supportive therapy during their hospital visits. Assessments included state-trait anxiety inventory, Beck's depression inventory, symptom checklist, common toxicity criteria, and functional living index-cancer. Assessments were done at baseline, after surgery, before, during, and after RT and six cycles of CT. RESULTS: Both groups had similar baseline scores. There were 29 dropouts 12 (yoga) and 17 (controls) following surgery. Sixty-nine participants contributed data to the current analysis (33 in yoga, and 36 in controls). An ANCOVA, adjusting for baseline differences, showed a significant decrease for the yoga intervention as compared to the control group during RT (first result) and CT (second result), in (i) anxiety state by 4.72 and 7.7 points, (ii) depression by 5.74 and 7.25 points, (iii) treatment-related symptoms by 2.34 and 2.97 points, (iv) severity of symptoms by 6.43 and 8.83 points, (v) distress by 7.19 and 13.11 points, and (vi) and improved overall quality of life by 23.9 and 31.2 points as compared to controls. Toxicity was significantly less in the yoga group (P = 0.01) during CT. CONCLUSION: The results suggest a possible use for yoga as a psychotherapeutic intervention in breast cancer patients undergoing conventional treatment.
RESUMEN
The functional association of NPM1 with Aurora kinases is well documented. Surprisingly, although NPM1 is a well characterized phosphoprotein, it is unknown whether it is a substrate of Aurora kinases. We have found that Aurora kinases A and B can phosphorylate NPM1 at a single serine residue, Ser125, in vitro and in vivo. Phosphorylated-S125-NPM1 (pS125-NPM1) localizes to the midbody region during late cytokinesis where it colocalizes with Aurora B. The overexpression of mutant (S125A) NPM1 resulted in the deregulation of centrosome duplication and mitotic defects possibly due to cytokinesis failure. These data suggest that Aurora kinase B-mediated phosphorylation of NPM1 plays a critical role during mitosis, which could have wider implications in oncogenesis.
Asunto(s)
Aurora Quinasa B/fisiología , Proteínas Nucleares/metabolismo , Procesamiento Proteico-Postraduccional , Animales , Aurora Quinasa A/química , Aurora Quinasa B/química , Carcinoma de Células Escamosas/enzimología , Transformación Celular Neoplásica/metabolismo , Centrosoma/metabolismo , Células HEK293 , Humanos , Ratones , Neoplasias de la Boca/enzimología , Células 3T3 NIH , Proteínas Nucleares/química , Nucleofosmina , Fosforilación , Transporte de Proteínas , TelofaseRESUMEN
CONTEXT AND AIM: Complementary and alternative therapies (CAM) are gaining popularity amongst patients as add on to conventional medicine. Yoga stands third amongst all CAM that is being used by cancer patients today. Different schools of yoga use different sets of practices, with some using a more physical approach and many using meditation and/or breathing. All these modules are developed based on the needs of the patient. This paper is an attempt to provide the basis for a comprehensive need based integrative yoga module for cancer patients at different stages of treatment and follow up. In this paper, the holistic modules of the integrated approach of yoga therapy for cancer (IAYTC) have been developed based on the patient needs, as per the observations by the clinicians and the caregivers. Authors have attempted to systematically create holistic modules of IAYTC for various stages of the disease and treatment. These modules have been used in randomized trials to evaluate its efficacy and have shown to be effective as add-on to conventional management of cancer. Thus, the objective of this effort was to present the theoretical basis and validate the need based holistic yoga modules for cancer patients. MATERIALS AND METHODS: Literature from traditional texts including Vedas, Ayurveda, Upanishads, Bhagavat Gita, Yoga Vasishtha etc. and their commentaries were looked into for references of cancer and therapeutic directives. Present day scientific literature was also explored with regards to defining cancer, its etiopathology and its management. Results of studies done using CAM therapies were also looked at, for salient findings. Focused group discussions (FGD) amongst researchers, experienced gurus, and medical professionals involved in research and clinical cancer practice were carried out with the objectives of determining needs of the patient and yoga practices that could prove efficient. A list of needs at different stages of conventional therapies (surgery, chemotherapy and radiation therapy) was listed and yoga modules were developed accordingly. Considering the needs, expected side effects, the energy levels and the psychological states of the participants, eight modules evolved. RESULTS: The results of the six steps for developing the validated module are reported. Step 1: Literature review from traditional yoga and ayurveda texts on etiopathogenesis and management of cancer (arbuda), and the recent literature on cancer stem cells and immunology of cancer. Step 2: Focused group discussions and deliberations to compile the needs of patients based on the expected side effects, energy levels and the psychological state of the patient as observed by the caregivers and the clinicians. Step 3: Content validation through consensus by the experts for the eight modules of IAYTC that could be used as complimentary to conventional management of cancer at different stages during and after the diagnosis was created. Step 4: Field testing for safety and feasibility of the modules through pilot studies. Step 5: Compilation of the results of efficacy trials through RCTs and step 6: A review of our studies on mechanisms to offer evidence for action of IAYTC on psycho-neuro-immunological pathways in cancer. CONCLUSION: The evidence from the traditional knowledge and recent scientific studies validates eight modules of integrated approach of yoga therapy for cancer that can be used safely and effectively as complimentary during all conventional cancer therapies.
Asunto(s)
Neoplasias/terapia , Yoga , Terapia Combinada , Medicina Basada en la Evidencia , Grupos Focales , Salud Holística , Humanos , Salud Mental , Neoplasias/patología , Neoplasias/fisiopatología , Neoplasias/psicología , Desarrollo de Programa , Evaluación de Programas y Proyectos de Salud , Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como Asunto , Proyectos de Investigación , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
Altered histone acetylation is associated with several diseases, including cancer. We report here that, unlike in most cancers, histones are found to be highly hyperacetylated in oral squamous cell carcinoma (OSCC; oral cancer) patient samples. Mechanistically, overexpression, as well as enhanced autoacetylation, of p300 induced by nucleophosmin (NPM1) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) causes the hyperacetylation, which is nitric oxide (NO) signal dependent. Inhibition of the histone acetyltransferase (HAT) activity of p300 by a water-soluble, small molecule inhibitor, Hydrazinocurcumin (CTK7A), substantially reduced the xenografted oral tumor growth in mice. These results, therefore, not only establish an epigenetic target for oral cancer, but also implicate a HAT inhibitor (HATi) as a potential therapeutic molecule.
Asunto(s)
Curcumina/análogos & derivados , Histona Acetiltransferasas/antagonistas & inhibidores , Histonas/metabolismo , Hidrazinas/química , Hidrazinas/farmacología , Neoplasias de la Boca/metabolismo , Óxido Nítrico/metabolismo , Agua/química , Acetilación/efectos de los fármacos , Animales , Proliferación Celular/efectos de los fármacos , Senescencia Celular/efectos de los fármacos , Curcumina/química , Curcumina/farmacología , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Células HeLa , Histona Acetiltransferasas/metabolismo , Humanos , Ratones , Ratones Desnudos , Neoplasias de la Boca/enzimología , Neoplasias de la Boca/genética , Neoplasias de la Boca/patología , Proteínas Nucleares/metabolismo , Nucleofosmina , Solubilidad , Regulación hacia Arriba/efectos de los fármacos , Factores de Transcripción p300-CBP/metabolismoRESUMEN
Surgical excision of the maxilla either as a primary procedure or after radiotherapy continues to play an important role in the management of carcinoma of the maxillary sinus. A majority of these cancers are seen in T3-T4 stage. Recurrence at the infratemporal fossa has been recognized as a major cause of failure. Although the importance of inclusion of the pterygopalatine fossa in the field of excision has been recognized, there is no uniform approach for en bloc removal of the pterygopalatine fossa. Transmandibular approach has been described for purpose and practiced at the Bangalore Institute of Oncology for the past 8 years with success. This paper presents the technique used, its benefits and the results obtained.
Asunto(s)
Carcinoma de Células Escamosas/cirugía , Países en Desarrollo , Mandíbula/cirugía , Neoplasias del Seno Maxilar/cirugía , Seno Maxilar/cirugía , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/radioterapia , Terapia Combinada , Estudios de Seguimiento , Humanos , India , Mandíbula/patología , Maxilar/patología , Maxilar/cirugía , Seno Maxilar/patología , Neoplasias del Seno Maxilar/patología , Neoplasias del Seno Maxilar/radioterapia , Estadificación de Neoplasias , Osteotomía/métodos , Complicaciones Posoperatorias/diagnóstico por imagen , Radioterapia Adyuvante , Tomografía Computarizada por Rayos XRESUMEN
Nucleophosmin (NPM1) is a multifunctional protein involved in the regulation of centrosome duplication, ribosome biogenesis, genomic stability, histone chaperone function, and transcription. Overexpression of NPM1 is associated with cancers of diverse histological origins. Here, we have found that p300-mediated acetylation of NPM1 modulates its subcellular localization and augments its oncogenic potential. Acetylated NPM1 is predominantly localized in the nucleoplasm, where it associates with transcriptionally active RNA polymerase II. Deacetylation of NPM1 is brought about by human SIRT1 and reduces its transcriptional activation potential. Remarkably, increased levels of acetylated NPM1 were found in grade II and III oral squamous cell carcinoma (OSCC) patient samples. Small interfering RNA (siRNA)-mediated knockdown of NPM1 in an OSCC cell line, followed by microarray analysis and chromatin immunoprecipitation experiments, revealed that some of the genes involved in oral cancer malignancy are regulated by NPM1 and have acetylated NPM1 localized at their promoters. Either suppression of p300 by siRNA or mutation of acetylatable lysine residues of NPM1 resulted in reduced occupancy of acetylated NPM1 on the target gene promoter concomitant with its decreased transcript levels. These observations suggest that acetylated NPM1 transcriptionally regulates genes involved in cell survival and proliferation during carcinogenesis.