RESUMO
PURPOSE: Accurate understanding of the genomic and transcriptomic data provided by next-generation sequencing (NGS) is essential for the effective utilization of precision oncology. Molecular tumor boards (MTBs) aim to translate the complex data in NGS reports into effective clinical interventions. Often, MTB treatment recommendations differ from those in the NGS reports. In this study, we analyze the discordance between these recommendations and the rationales behind the discordances, in a non-high-income setting, with international input to evaluate the necessity of MTB in clinical practice. METHODS: We collated data from MTB that were virtually hosted in Chennai, India. We included patients with malignancies who had NGS reports on solid tissue or liquid biopsies, and excluded those with incomplete data. MTB forms and NGS reports of each clinical case were analyzed and evaluated for recommendation concordance. Concordance was defined as an agreement between the first recommendation in the MTB forms and the therapeutic recommendations suggested in the NGS report. Discordance was the absence of the said agreement. The rationales for discordance were identified and documented. RESULTS: Seventy MTB reports were analyzed with 49 cases meeting the inclusion criteria. The recommendation discordance was 49% (24 of 49). Discordant recommendations were mainly due to low level of evidence for the drug (75% of cases). CONCLUSION: The discordance between MTB and NGS vendor recommendations highlights the clinical utility of MTB. The educational experiences provided by this initiative are an example of how virtual academic collaborations can enhance patient care and provider education across geographic borders.
Assuntos
Neoplasias , Humanos , Neoplasias/diagnóstico , Neoplasias/genética , Neoplasias/terapia , Medicina de Precisão , Índia , Oncologia , Sequenciamento de Nucleotídeos em Larga EscalaRESUMO
Low- and middle-income countries (LMICs) represent a diverse group of regions with varied cancer presentation. Drug development and accessibility across these regions have primarily been dependent on the trials initiated and conducted across high-income countries. Representation of LMIC regions in these trials in terms of study population has been minimal, leading to inequitable distribution of optimal and affordable cancer care. In spite of many challenges, LMICs have now increasingly been able to contribute to anticancer drug development. The opportunities present in LMICs must be explored and used in conjunction with due collaborative efforts from high-income countries, health care planners, and regulatory agencies. Global drug development trials should not only factor in suitable representation of LMICs but also design studies with pragmatic objectives and endpoints so that the trial results lead to equitable and affordable cancer care. Strengthening collaboration between cancer researchers from LMICs and high-income countries and empowering the local investigator with adequate resources will help remove current disparities.
Assuntos
Desenvolvimento de Medicamentos , Neoplasias , Atenção à Saúde , Países em Desenvolvimento , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/epidemiologia , PobrezaRESUMO
Adrenocortical carcinoma (ACC) comprises approximately 0.02% of all malignant tumours, which are a very small fraction of a group of cancers that affect in 0.7 to 2 in 1 000 000 people per year. Recurrence is very common even after complete resection and prognosis is poor. We report a case of a sporadic form of ACC found in a 41-year-old Asian Bangladeshi man. His tumour was surgically excised completely with negative margins and he did not receive any adjuvant therapy. Four years later, adrenal adenoma was developed at his opposite side which was also excised. Then after a total duration of 7 years, he developed recurrence in both adrenal glands and extensive metastases to bilateral lungs, liver and abdominal wall. As per FIRM-ACT study, we started treatment with etoposide, doxorubicin, cisplatin plus mitotane (EDP-M), and the patient responded dramatically. He became symptom free and achieved radiological partial response just on completion of three cycles. To our knowledge, this is the first case of ACC in Bangladesh published in the literature. Managing rare cancers is always challenging due to the fact that clinicians lack practical experience in it. We believe that patient with a rare cancer with poor prognosis like ACC may also survive long, and extensive metastases can also be controlled.
Assuntos
Neoplasias do Córtex Suprarrenal/terapia , Carcinoma Adrenocortical/terapia , Recidiva Local de Neoplasia/terapia , Glândulas Suprarrenais/cirurgia , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica , Bangladesh , Doença Crônica , Cisplatino/uso terapêutico , Terapia Combinada , Doxorrubicina/uso terapêutico , Etoposídeo/uso terapêutico , Humanos , Masculino , Mitotano/uso terapêutico , Prognóstico , Fatores de Tempo , Resultado do TratamentoRESUMO
L-Tyrosine which is one of the terminal metabolites of highly regulated aromatic amino-acid biosynthesis pathway in Escherichia coli is a precursor for synthesis of L-Dopa. In this study, we report over production of L-Dopa by enhancing expression of rate limiting isoenzyme of shikimate kinase (aroL), chorismate synthase (aroC), aromatic-amino-acid aminotransferase (tyrB) and 3-phosphoshikimate 1-carboxyvinyltransferase (aroA) form a plasmid module harboring five enzymes under two inducible promoters converting shikimate to tyrosine. 4-hydroxyphenylacetate-3-hydrolase (hpaBC) which converts L-Tyrosine to L-Dopa was expressed constitutively from a separate plasmid module. Feedback deregulated expression of 3-Deoxy-D-arabinoheptulosonate-7-phosphate (DAHP) synthase (aroG*) replacing wild type aroG under its natural promoter led to enhancement of L-Dopa production. Deletion of transcriptional repressor tyrR and links to other competing pathways improved titers of L-Dopa. We focused on having a balanced flux by constitutive expression of pathway enzymes from plasmid constructs rather than achieving higher amounts of catalytic protein by induction. We observed glycerol when used as a carbon source for the final strain led to low acid production. The best performing strain led to decoupling of acid production and product formation in bioreactor. Fed batch analysis of the final strain led to 12.5 g/L of L-Dopa produced in bioreactor.
Assuntos
Escherichia coli , Genoma Bacteriano , Glicerol/metabolismo , Levodopa/biossíntese , Engenharia Metabólica , Microrganismos Geneticamente Modificados , Plasmídeos , Escherichia coli/genética , Escherichia coli/metabolismo , Levodopa/genética , Microrganismos Geneticamente Modificados/genética , Microrganismos Geneticamente Modificados/metabolismoRESUMO
L-Dopa and dopamine are important pathway intermediates toward the synthesis of catecholamine such as epinephrine and norepinephrine from amino acid L-tyrosine. Dopamine, secreted from dopaminergic nerve cells, serves as an important neurotransmitter. We report the synthesis of dopamine by extending the aromatic amino acid pathway of Escherichia coli DH5α by the expression of 4-hydroxyphenylacetate-3-hydrolase (HpaBC) from E. coli and an engineered dopa decarboxylase (DDC) from pig kidney cell. The activity of HpaBC and DDC require 200 µM iron supplementation and 50 µM vitamin B6, respectively as additives to the growth media. The maximum concentration of L-dopa and dopamine obtained from the broth was around 26 and 27 mg/L after 24 hr of separate shake flask studies. We observed that in the presence of dopamine synthesized in vivo host growth was remarkably enhanced. These observations lead us to an interesting finding about the role of these catecholamines on bacterial growth. It is clear that synthesis of dopamine in vivo actually promotes growth much efficiently as compared to when dopamine is added to the system from outside. From HPLC and GC-MS data it was further observed that L-dopa was stable within the observable time of experiments whereas dopamine actually was subjected to degradation via oxidation and host consumption.
Assuntos
Dopamina/metabolismo , Escherichia coli/metabolismo , Animais , Dopa Descarboxilase/genética , Dopa Descarboxilase/metabolismo , Dopamina/genética , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Microbiologia Industrial , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Engenharia de Proteínas/métodos , SuínosRESUMO
PURPOSE: The risk of breast cancer can be influenced by certain dietary components, such as the amount and type of dietary fatty acids ingested. Docosahexaenoic acid (DHA), a component of fish oil, is known to suppress rat mammary carcinogenesis, reduce cell growth and induce apoptosis in human breast cancer cell lines. The purpose of this study was to develop a novel nanoliposomal formulation that would encapsulate a concentrated amount of DHA and utilize lipids that could protect DHA from pH fluctuations and oxidation. METHODS: We developed an acid stable liposome formulation of DHA by utilizing ether and phytanyl lipids similar in structure to those found in Archaea, known to endure high acidity and temperature; we compared its biological activities with free DHA in human breast cancer cells. RESULTS: The mean size of the liposomal DHA was 137 ± 12 nm with a slightly negative charge; the encapsulation efficiency of DHA in the liposomes as determined by LC-MS/MS ranged from 60 to 80%; our formulation is resistant to oxidation and stable over a range of pH (1.0-7.4) at 37 °C for a duration of two hours. In MCF-7 cells, liposomal DHA (IC50 38.8 µM) significantly reduced cell viability more effectively than free DHA (IC50 72.5 µM, p = 0.0017). In MDA-MB-231 cells, liposomal DHA was also marginally more effective. Liposomal DHA was more effective than free DHA in inducing apoptosis in both cell lines. It altered proteins involved in cell growth, cell cycle, and apoptosis more effectively than free DHA in both cell lines; it up-regulated p21 and cleaved PARP, while P-AKT and P-S6 were down-regulated. CONCLUSIONS: We developed a novel biologically active acid stable liposomal DHA as a potentially useful formulation for breast cancer prevention.
Assuntos
Anticarcinógenos/administração & dosagem , Neoplasias da Mama/prevenção & controle , Mama/efeitos dos fármacos , Ácidos Docosa-Hexaenoicos/administração & dosagem , Anticarcinógenos/farmacologia , Apoptose/efeitos dos fármacos , Mama/patologia , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ácidos Docosa-Hexaenoicos/farmacologia , Feminino , Óleos de Peixe/administração & dosagem , Óleos de Peixe/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Lipossomos , Células MCF-7 , OxirreduçãoRESUMO
Umbilical metastases [Sister Mary Joseph's nodules (SMJN)] are relatively rare and are associated usually with advanced intra-abdominal tumors from the gastrointestinal tract (GIT) or from the gynecological malignancies and they carry poor prognosis. Here we report a case of carcinoma caecum whose initial presentation was with umbilical metastases and a review of literature in relation to the umbilical metastases from colonic tumors.
RESUMO
Squamous cell carcinoma in children and adolescents is extremely rare. Less than 80 case reports have been reported in the literature since it was first reported in 1868. In this article, we intend to report a case where a 16-year-old girl who presented with complaints of change in voice was found to have early-stage vocal cord carcinoma on evaluation.
RESUMO
Recent studies suggest that low vitamin D-binding protein (VDBP aka group-specific complement or Gc) concentrations may be linked with inflammatory-mediated conditions, including asthma, chronic obstructive pulmonary disease, and cancer. However, these studies may be confounded by substantial racial and ethnic or genetic differences. The purpose of this study was to test the hypothesis that circulating VDBP concentrations are significantly associated with genetic ancestry. We used a validated high-performance liquid chromatography tandem mass spectrometry assay of 25-hydroxyvitamin D3 and its downstream metabolite 24,25-dihydroxyvitamin D3. VDBP concentrations (milligrams per liter) were measured in duplicate using a commercial enzyme-linked immunosorbent assay among healthy African American (n = 56) and Caucasian American (n = 60) participants. Ancestry informative markers across the genome were used to estimate individual genetic ancestry proportions, designed to robustly distinguish between West African and European ancestry. Genotype-defined Gc isoforms were defined using rs7041 and rs4588 combination groups. VDBP concentration was correlated with both Gc isoform (r = 0.93, P < 0.001) and West African genetic ancestry (r = -0.66, P < 0.001). In the final model, Gc isoform, the catabolic ratio of serum vitamin D, oral contraceptive use, and body mass index remained significantly associated with VDBP concentration, after adjustment for genetic ancestry. Failure to adjust for Gc isoform may lead to spurious associations in studies of VDBP concentration and disease risk, particularly when the condition of interest may also be associated with genetic ancestry. The higher circulating VDBP concentrations and higher vitamin D catabolic rate among Caucasian Americans observed here appear to be consistent with lower bone mineral density and racial and ethnic differences in vitamin D-inducing cytokines.
Assuntos
Proteína de Ligação a Vitamina D/sangue , Adulto , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Masculino , Espectrometria de Massas em Tandem , Adulto JovemRESUMO
We report here a detailed time course study of the individual and combined chemopreventive effects of Tamoxifen (Tam) and a high fish oil (FO) diet on multiple histologic parameters of mammary carcinogenesis. Groups of female Sprague-Dawley rats were injected ip with 1-methyl-1-nitrosourea at 50 days of age and assigned to either a control diet (20% corn oil [CO]) or a FO-rich diet (10% FO + 10% CO) in the presence and absence of Tam in the diet (0.6 ppm). Rats were sacrificed at weeks 4 (before palpable tumors), 8 and 12 (when â¼90% of control rats had palpable tumors). Our results demonstrate a major effect of Tam in inhibiting the development of early preneoplastic lesions. FO, while having a marginal protective effect of it own, enhanced the antitumor action of Tam on all histologic parameters of carcinogenesis, although the effects of the combination were not statistically different from those of Tam alone. The combination of FO and Tam was the only intervention that induced regression of established preneoplastic lesions. We also found that in contrast to plasma, only target tissue n-3 fatty acids (FAs) levels correlated with select tissue biomarkers of carcinogenesis whose expression was altered in a manner predictive of a protective effect. Our results demonstrating the potentially superior chemopreventive efficacy of Tam and n-3FA have important translational implications. Our data also emphasize the importance of local factors in affecting target tissue levels and biologic effects of n-3FA.
Assuntos
Antineoplásicos/farmacologia , Carcinogênese/efeitos dos fármacos , Ácidos Graxos Ômega-3/farmacologia , Neoplasias Mamárias Experimentais/prevenção & controle , Tamoxifeno/farmacologia , Animais , Biomarcadores Tumorais/metabolismo , Carcinogênese/genética , Carcinogênese/metabolismo , Quimioprevenção/métodos , Dieta , Feminino , Óleos de Peixe/farmacologia , Antígeno Ki-67/genética , Glândulas Mamárias Animais/metabolismo , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/metabolismo , Metilnitrosoureia , Lesões Pré-Cancerosas/tratamento farmacológico , Lesões Pré-Cancerosas/genética , Lesões Pré-Cancerosas/metabolismo , Ratos , Ratos Sprague-DawleyRESUMO
We used a proteomic approach to gain insights into the mechanisms of protection at the protein level by a high n-3:n-6 ratio in the absence and presence of Tamoxifen. Four groups were treated with 1-methyl-1-nitrosourea (MNU) and fed the following diets with varied n-3:n-6 ratios; group 1 = 1:1; groups 2 and 3 = 10:1 and 25:1, respectively; group 4: (25:1) plus Tamoxifen (1 mg/kg diet). The plasma from six rats/group was pooled and analyzed with the isobaric tags for relative and absolute quantitation method; 148 proteins were identified with 95% confidence by ProteinPilot 4.0. In plasma of rats fed 10:1, 25:1 n-3:n-6, and 25:1 plus Tamoxifen, the number of proteins that met our criteria (P ≤ 0.05, error factor ≤ 2) were 10, 14, and 19 proteins, respectively. Selected proteins were further validated by Western blotting. Compared to 1:1, both 10:1 and 25:1 diets upregulated vitamin D binding protein, gelsolin, and 14-3-3 sigma, reported to have tumor suppressive effects, whereas alpha-1B-glycoprotein, which has been reported to be elevated in the serum of breast cancer patients was decreased. Compared to 25:1, the 25:1 plus Tamoxifen diet downregulated apolipoprotein E, haptoglobin, and inter-α-inhibitor H4 heavy chain. Ingenuity pathway analysis determined that the trends of specific proteins were related to lipid metabolism in the 25:1 n-3:n-6 group, whereas the 25:1 n-3:n-6 plus Tamoxifen group included proteins involved in cancer and inflammation. Our results show that several proteins were altered in a manner consistent with chemoprevention. Such proteins may serve as biomarkers to monitor efficacy of n-3 and Tamoxifen in future clinical chemoprevention trials.
Assuntos
Biomarcadores Tumorais/metabolismo , Ácidos Graxos Ômega-6/farmacologia , Neoplasias Mamárias Experimentais/metabolismo , Metilnitrosoureia/toxicidade , Tamoxifeno/farmacologia , Alquilantes/toxicidade , Animais , Antineoplásicos Hormonais/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica , Dieta , Feminino , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/tratamento farmacológico , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
The survival rate for breast cancer drops dramatically once the disease progresses to the metastatic stage. Selenium (Se) is an essential micronutrient credited with having high anticancer and chemopreventive properties. In our study, we investigated if dietary Se supplementation modified breast cancer development in vivo. Three diets supplemented with sodium selenite, methylseleninic acid (MSA) or selenomethionine (SeMet), as well as a Se-deficient and a Se-adequate diet were fed to mice before mammary gland inoculation of 4T1.2 cells. The primary tumor growth, the numbers of cancer cells present in lungs, hearts, livers, kidneys and femurs and several proinflammatory cytokines were measured. We found that inorganic selenite supplementation provided only short-term delay of tumor growth, whereas the two organic SeMet and MSA supplements provided more potent growth inhibition. These diets also affected cancer metastasis differently. Mice fed selenite developed the most extensive metastasis and had an increased incidence of kidney and bone metastasis. On the other hand, mice fed the SeMet diet showed the least amount of cancer growth at metastatic sites. The MSA diet also provided some protection against breast cancer metastasis although the effects were less significant than those of SeMet. The cytokine profiles indicated that serum levels of interlukin-2, interleukin-6, interferon γ and vascular endothelial growth factor were elevated in SeMet-supplemented mice. There was no significant difference in tumor growth and the patterns of metastasis between the Se-deficient and Se-adequate groups. Our data suggest that organic Se supplementation may reduce/delay breast cancer metastasis, while selenite may exacerbate it.
Assuntos
Neoplasias Ósseas/secundário , Suplementos Nutricionais , Neoplasias Renais/secundário , Neoplasias Pulmonares/secundário , Neoplasias Mamárias Animais/patologia , Animais , Western Blotting , Neoplasias Ósseas/dietoterapia , Feminino , Citometria de Fluxo , Interferon gama/genética , Interferon gama/metabolismo , Interleucina-2/genética , Interleucina-2/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Neoplasias Renais/dietoterapia , Neoplasias Pulmonares/dietoterapia , Neoplasias Mamárias Animais/dietoterapia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Compostos Organosselênicos/administração & dosagem , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Selenometionina/administração & dosagem , Selenito de Sódio/administração & dosagem , Células Tumorais CultivadasRESUMO
BACKGROUND: Aging-related changes in important cellular pathways in the prostate may promote a permissive environment for an increased risk for prostatic disease development such as prostate cancer. Our objectives were to examine for such changes, by systematically determining the effects of growth and development and aging on proteomic profiles in different lobes of the rat prostate. METHODS: Prostate lobes (dorsolateral lobe, DL and ventral lobe, VL) were obtained from male Fisher rats of various ages representing young (4 months), mature (12 months), old (18 months), and very old (24 months). Differentially expressed proteins between age groups in each lobe were identified using a proteomic approach, isobaric Tags for Relative and Absolute Quantitation (iTRAQ). Select changes in the DL and VL were verified by immunoblot analysis. RESULTS: iTRAQ identified 317 proteins with high confidence. iTRAQ discovered 12 and 6 proteins significantly modulated in response to growth and development in the DL and VL, respectively, and 42 and 29 proteins significantly modulated in response to aging in the DL and VL, respectively. Proteins modulated during growth and development in the DL and VL are involved in a variety of biological processes including cell communication and development, whereas proteins modulated during aging were predominantly related to antioxidant activity and immunity. Immunoblot analysis verified age-related changes for α-1 antitrypsin, annexin A1, hypoxia up-regulated protein 1, and 78 kDa glucose-regulated protein. CONCLUSIONS: Aging results in changes in numerous prostatic proteins and pathways which are mainly linked to inflammation and may lead to prostatic disease development.
Assuntos
Envelhecimento/fisiologia , Longevidade/fisiologia , Próstata/crescimento & desenvolvimento , Proteômica/tendências , Transcriptoma/fisiologia , Animais , Masculino , Proteômica/métodos , Ratos , Ratos Endogâmicos F344RESUMO
The synthetic organoselenium agent 1,4-phenylenebis(methylene)selenocyanate (p-XSC) and its glutathione (GSH) conjugate (p-XSeSG) are potent chemopreventive agents in several preclinical models. p-XSC is also an effective inducer of GSH in mouse lung. Our objectives were to test the hypothesis that GSH induction by p-XSC occurs through upregulation of the rate-limiting GSH biosynthetic enzyme glutamylcysteine ligase (GCL), through activation of antioxidant response elements (AREs) in GCL genes via activation of nuclear factor-erythroid 2-related factor 2 (Nrf2). p-XSC feeding (10 ppm Se) increased GSH (230%) and upregulated the catalytic subunit of GCL (GCLc) (55%), extracellular-related kinase (220%), and nuclear Nrf2 (610%) in lung but not liver after 14 days in the rat (P<0.05). Similarly, p-XSeSG feeding (10 ppm) induced lung GCLc (88%) and GSH (200%) (P<0.05), whereas the naturally occurring selenomethionine had no effect. Both p-XSC and p-XSeSG activated a luciferase reporter in HepG2 ARE-reporter cells up to threefold for p-XSC and greater than or equal to fivefold for p-XSeSG. Luciferase activation by p-XSeSG was associated with enhanced levels of GSH, GCLc, and nuclear Nrf2, which were significantly reduced by co-incubation with short interfering RNA targeting Nrf2. The dependence of GCL induction on Nrf2 was confirmed in Nrf2-deficient mouse embryonic fibroblasts, in which p-XSeSG induced GCL subunits in wild-type but not in Nrf2-deficient cells (P<0.05). These results indicate that p-XSC may act through the Nrf2 pathway in vivo and that p-XSeSG is the putative metabolite responsible for such activation, thus offering p-XSeSG as a less toxic, yet highly efficacious, inducer of GSH.
Assuntos
Glutamato-Cisteína Ligase/biossíntese , Glutationa/biossíntese , Fator 2 Relacionado a NF-E2/metabolismo , Compostos Organosselênicos/farmacologia , Animais , Linhagem Celular , Células Hep G2 , Humanos , Fígado/metabolismo , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , Interferência de RNA , RNA Interferente Pequeno , RatosRESUMO
Aging represents a major risk factor for prostate cancer; however, mechanisms responsible for this relationship remain unclear. Preclinical and some clinical investigations support the protective role of selenium against prostate cancer possibly through the reduction of oxidative stress. While increased levels of oxidative stress together with decreases in selenium and the major cellular antioxidant glutathione (GSH) are common in tissues of old animals, there is little data available on these parameters in the prostate. In the present study we have compared the levels of selenium, GSH and protein-bound GSH (GSSP) in blood and prostate tissues in young (4-month), mature (12-month), old (18 month), and very old (24 month) male F344 rats. Each prostate lobe (dorsolateral, DL; anterior, AL; ventral, VL) was analyzed separately based upon their differing potential for prostate cancer development. At all ages, selenium levels were lowest in DLAssuntos
Envelhecimento/metabolismo
, Glutationa/metabolismo
, Próstata/metabolismo
, Selênio/metabolismo
, Envelhecimento/sangue
, Envelhecimento/patologia
, Animais
, Peso Corporal/fisiologia
, Glutationa/sangue
, Masculino
, Tamanho do Órgão/fisiologia
, Próstata/anatomia & histologia
, Ratos
, Ratos Endogâmicos F344
, Selênio/sangue
RESUMO
The use of regular yeast (RY) and selenium-enriched yeast (SEY) as dietary supplement is of interest because the Nutritional Prevention of Cancer (NPC) trial revealed that SEY but not RY decreased the incidence of prostate cancer (PC). Using two-dimensional difference in gel electrophoresis (2D-DIGE)-tandem mass spectrometry (MS/MS) approach, we performed proteomic analysis of RY and SEY to identify proteins that are differentially expressed as a result of selenium enrichment. 2D-DIGE revealed 96 candidate protein spots that were differentially expressed (p≤0.05) between SEY and RY. The 96 spots were selected, sequenced by LC/MS/MS and 37 proteins were unequivocally identified. The 37 identified proteins were verified with ProteinProphet software and mapped to existing Gene Ontology categories. Furthermore, the expression profile of 5 of the proteins with validated or putative roles in the carcinogenesis process, and for which antibodies against human forms of the proteins are available commercially was verified by western analysis. This study provides evidence for the first time that SEY contains higher levels of Pyruvate Kinase, HSP70, and Elongation factor 2 and lower levels of Eukaryotic Translation Initiation Factor 5A-2 and Triosephosphate Isomerase than those found in RY.
Assuntos
Regulação Fúngica da Expressão Gênica/fisiologia , Proteoma/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Selênio/farmacologia , Anticorpos Antineoplásicos/química , Suplementos Nutricionais/análise , Humanos , Incidência , Masculino , Neoplasias da Próstata/epidemiologia , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/prevenção & controle , Proteoma/análise , Proteômica/instrumentação , Proteômica/métodos , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/análise , SoftwareRESUMO
Epidemiologic studies on the protective role of omega-3 fatty acids (n:3) on breast cancer prevention remain inconclusive but studies in preclinical models provide more positive outcome. However, the mechanisms accounting for the protective effect of n:3 are not defined. In the present study, conducted in the N-methyl-N-nitrosourea-induced rat mammary carcinogenesis model, we examined the effects of n:3 individually and in combination with the anti-estrogen Tamoxifen (Tam) on a comprehensive panel of systemic and preneoplastic mammary gland restricted biomarkers which may be critical in the progression to invasive cancer. We observed that fish oil (FO) rich diets significantly reduced Ki67 expression in hyperplastic lesions, while cleaved caspase-3 expression was not affected. Dietary FO and/or Tam did not have major effects on systemic oxidative stress biomarkers, based on oxidative damage to DNA measured as 8-hydroxy-2-deoxyguanosine (8-OH-dG) and lipid peroxidation assessed as thiobarbituric acid reactive substances (TBARS). Tissue levels of 8-isoprostane, on the other hand, were markedly reduced (p<0.0001) in FO-fed rats, possibly as a result of FO-induced depletion of arachidonic acid in the mammary gland. These results suggest that the protective effect of n:3 in this experimental system is not mediated by changes in the levels of oxidative stress but may result from suppression of arachidonic acid-specific pathways.
Assuntos
Óleos de Peixe/farmacologia , Glândulas Mamárias Animais/efeitos dos fármacos , Neoplasias Mamárias Experimentais/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Lesões Pré-Cancerosas/metabolismo , Tamoxifeno/farmacologia , Animais , Biomarcadores/metabolismo , Caspase 3/metabolismo , Transformação Celular Neoplásica/induzido quimicamente , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/metabolismo , Dieta , Ativação Enzimática/efeitos dos fármacos , Ácidos Graxos/metabolismo , Feminino , Glutationa/sangue , Glutationa Peroxidase/metabolismo , Antígeno Ki-67/metabolismo , Glândulas Mamárias Animais/metabolismo , Glândulas Mamárias Animais/patologia , Metilnitrosoureia , Ratos , Ratos Sprague-Dawley , Fatores de TempoRESUMO
In these experiments, we tested the hypothesis that inhibition of the estrogen receptor (ER) with Tamoxifen and activation of PPARγ with fish oil (FO) rich in omega-3 (n-3; known PPAR agonists) inhibit the development of hormone-independent breast cancer in view of the known crosstalk between the ER and PPARγ pathways. We selected the polyoma middle T transgenic mouse model, since in this system the development of ER- tumors is preceded by ER positive preneoplastic lesions. Tamoxifen admixed with a 20% corn oil (CO) modified AIN-76A diet delayed mammary carcinogenesis and inhibited tumor multiplicity, volume, and weight in a dose-dependent (1, 10, and 100 ppm) fashion. Administration of increasing concentrations of FO in the diet (5%, 10%, and 17%) did not affect any of the tumor parameters. Combined administration of different doses of Tamoxifen and FO delayed carcinogenesis and suppressed tumor multiplicity and volume to the same extent as Tamoxifen alone. Mice fed 10% FO exhibited the expected increase in n-3/n-6 ratio in plasma and tumor based on diet analysis. Further increase in the n-3/n-6 ratio was not observed in mice fed the 17% FO diet. FO reduced tissue levels of arachidonic acid and its metabolite PGF-2α. Our results support the role of ER expression by preneoplastic lesions in the development of hormone-independent tumors and consequently the importance of including ER targeting in combination with mechanistically based novel chemopreventive agents.