RESUMEN
The special AT-rich sequence binding protein (SATB2) has been reported to be a specific immunohistochemical marker for colorectal carcinoma; however, correlation of SATB2 expression with molecular alterations commonly assessed in colorectal carcinoma has not been performed. We examined the immunohistochemical expression of SATB2 in 586 adenocarcinomas of the gastrointestinal (GI) tract and pancreas to assess its utility in diagnosis and analyze the clinicopathologic and molecular characteristics of colorectal carcinoma stratified by SATB2 expression. SATB2 and CDX2 expression were evaluated in 266 adenocarcinomas of lower GI tract origin (246 colorectal and 20 appendiceal mucinous), 208 adenocarcinomas of upper GI tract and small intestinal origin (74 esophagus/esophagogastric junction, 103 stomach, 20 duodenal, and 11 jejunoileal), and 112 pancreatic ductal adenocarcinomas. SATB2 expression was more frequently identified in adenocarcinomas of lower GI tract origin (222/266, 83%) compared with upper GI tract, small intestinal, or pancreatic origin (26/320, 8%) (P<0.001). Compared with CDX2 alone, dual positive expression for SATB2 and CDX2 (SATB2/CDX2) has a significantly higher specificity for adenocarcinoma of lower GI tract origin (94% vs. 57%, P<0.001). In colorectal carcinoma, loss of SATB2 expression was more frequently observed in DNA mismatch repair (MMR) protein deficient tumors (31%) compared with MMR protein proficient tumors (13%) (P<0.01). A BRAF V600E mutation was more frequently identified in colorectal carcinomas with loss of SATB2 expression compared with those with positive SATB2 expression (29% vs. 3%) (P<0.001). In summary, SATB2 expression is a relatively specific marker of lower GI tract origin; however, loss of SATB2 expression is more commonly seen in colorectal carcinoma with MMR protein deficiency and BRAF mutation.
Asunto(s)
Adenocarcinoma/química , Adenocarcinoma/genética , Biomarcadores de Tumor , Neoplasias Colorrectales/química , Neoplasias Colorrectales/genética , Reparación de la Incompatibilidad de ADN , Enzimas Reparadoras del ADN/análisis , Proteínas de Unión a la Región de Fijación a la Matriz/análisis , Mutación , Proteínas Proto-Oncogénicas B-raf/genética , Factores de Transcripción/análisis , Adenocarcinoma/patología , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/análisis , Biomarcadores de Tumor/genética , Neoplasias Colorrectales/patología , Regulación hacia Abajo , Femenino , Predisposición Genética a la Enfermedad , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Fenotipo , Proteínas Proto-Oncogénicas p21(ras)/genética , Estudios Retrospectivos , Análisis de Matrices TisularesRESUMEN
OBJECTIVES: To evaluate the relationship between the epithelial expression of hMLH1, MDM2, and p63 in lower lip carcinogenesis, comparing the immunostaining of these proteins in cases of actinic cheilitis (AC) and lower lip squamous cell carcinoma (SCC). STUDY DESIGN: Forty cases of AC and 40 cases of SCC were studied, both lesions were of lower lip. Histological sections of 3 µm were submitted to immunoperoxidase method, and 1000 cells were counted for immunohistochemical analysis of lesions. The results were analyzed quantitatively, and expression was compared by the Mann-Whitney, Student t-test, or one-way ANOVA, adopting a level of significance of 5%. RESULTS: A higher percentage of epithelial cells expressing hMLH1 was observed in cases of AC without dysplasia or mild dysplasia (721.23 ± 88.116), whereas fewer positive cells were observed in lower lip SSCs (255.03 ± 199.47) when compared to the AC group (P < 0.001). Immunoexpression of MDM2 was higher in SCCs of the lower lip compared with AC (P = 0.019). For p63 protein, the expression was higher in AC than in SCC (P = 0.045). CONCLUSION: The present results showed changes in the immunoexpression of hMLH1, MDM2, and p63 in epithelial cells from premalignant and malignant lip disease, supporting the hypothesis that these alterations are related to the process of lower lip carcinogenesis.
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Proteínas Adaptadoras Transductoras de Señales/análisis , Carcinogénesis , Enzimas Reparadoras del ADN/análisis , Neoplasias de los Labios/química , Labio/química , Proteínas Nucleares/análisis , Proteínas Proto-Oncogénicas c-mdm2/análisis , Factores de Transcripción/análisis , Proteínas Supresoras de Tumor/análisis , Carcinoma de Células Escamosas/química , Carcinoma de Células Escamosas/patología , Queilitis/metabolismo , Queilitis/patología , Células Epiteliales/química , Células Epiteliales/patología , Femenino , Humanos , Labio/patología , Neoplasias de los Labios/patología , Masculino , Persona de Mediana Edad , Mucosa Bucal/química , Mucosa Bucal/patología , Homólogo 1 de la Proteína MutL , Clasificación del Tumor , Lesiones Precancerosas/química , Lesiones Precancerosas/patología , Estudios RetrospectivosRESUMEN
OBJECTIVE: The aim of this study was to evaluate the effect of a novel phytoestrogen, α-Zearalanol, on Alzheimer's disease-related memory impairment and neuronal oxidation in ovariectomized mice. METHODS: Female C57/BL6 mice were ovariectomized or received sham operations and treatment with equivalent doses of 17ß-estradiol or α-Zearalanol for 8 weeks. Their spatial learning and memory were analyzed using the Morris water maze test. The antioxidant enzyme activities and reactive oxygen species generation, neuronal DNA oxidation, and MutT homolog 1 expression in the hippocampus were measured. RESULTS: Treatment with 17ß-estradiol or α-Zearalanol significantly improved spatial learning and memory performance in ovariectomized mice. In addition, 17ß-estradiol and α-Zearalanol attenuated the decrease in antioxidant enzyme activities and increased reactive oxygen species production in ovariectomized mice. The findings indicated a significant elevation in hippocampi neuronal DNA oxidation and reduction in MutT homolog 1 expression in estrogen-deficient mice, but supplementation with 17ß-estradiol or α-Zearalanol efficaciously ameliorated this situation. CONCLUSION: These results demonstrate that α-Zearalanol is potentially beneficial for improving memory impairments and neuronal oxidation damage in a manner similar to that of 17ß-estradiol. Therefore, the compound may be a potential therapeutic agent that can ameliorate neurodegenerative disorders related to estrogen deficiency.
Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Estradiol/uso terapéutico , Trastornos de la Memoria/tratamiento farmacológico , Ovariectomía , Estrés Oxidativo/efectos de los fármacos , Fitoestrógenos/uso terapéutico , Zeranol/análogos & derivados , Animales , Western Blotting , Daño del ADN/efectos de los fármacos , Enzimas Reparadoras del ADN/análisis , Femenino , Hipocampo/efectos de los fármacos , Inmunohistoquímica , Ratones , Ratones Endogámicos C57BL , Monoéster Fosfórico Hidrolasas/análisis , Reproducibilidad de los Resultados , Factores de Tiempo , Resultado del Tratamiento , Zeranol/uso terapéuticoRESUMEN
OBJECTIVE: The aim of this study was to evaluate the effect of a novel phytoestrogen, α-Zearalanol, on Alzheimer's disease-related memory impairment and neuronal oxidation in ovariectomized mice. METHODS: Female C57/BL6 mice were ovariectomized or received sham operations and treatment with equivalent doses of 17β-estradiol or α-Zearalanol for 8 weeks. Their spatial learning and memory were analyzed using the Morris water maze test. The antioxidant enzyme activities and reactive oxygen species generation, neuronal DNA oxidation, and MutT homolog 1 expression in the hippocampus were measured. RESULTS: Treatment with 17β-estradiol or α-Zearalanol significantly improved spatial learning and memory performance in ovariectomized mice. In addition, 17β-estradiol and α-Zearalanol attenuated the decrease in antioxidant enzyme activities and increased reactive oxygen species production in ovariectomized mice. The findings indicated a significant elevation in hippocampi neuronal DNA oxidation and reduction in MutT homolog 1 expression in estrogen-deficient mice, but supplementation with 17β-estradiol or α-Zearalanol efficaciously ameliorated this situation. CONCLUSION: These results demonstrate that α-Zearalanol is potentially beneficial for improving memory impairments and neuronal oxidation damage in a manner similar to that of 17β-estradiol. Therefore, the compound may be a potential therapeutic agent that can ameliorate neurodegenerative disorders related to estrogen deficiency. .
Asunto(s)
Animales , Femenino , Ratones , Enfermedad de Alzheimer/tratamiento farmacológico , Estradiol/uso terapéutico , Trastornos de la Memoria/tratamiento farmacológico , Ovariectomía , Estrés Oxidativo/efectos de los fármacos , Fitoestrógenos/uso terapéutico , Zeranol/análogos & derivados , Western Blotting , Daño del ADN/efectos de los fármacos , Enzimas Reparadoras del ADN/análisis , Hipocampo/efectos de los fármacos , Inmunohistoquímica , Monoéster Fosfórico Hidrolasas/análisis , Reproducibilidad de los Resultados , Factores de Tiempo , Resultado del Tratamiento , Zeranol/uso terapéuticoRESUMEN
About 40 different types of ginsenoside (ginseng saponin), a major pharmacological component of ginseng, have been identified along with their physiological activities. Among these, compound K has been reported to prevent the development of and the metastasis of cancer by blocking the formation of tumors and suppressing the invasion of cancerous cells. In this study, ginsenoside Rb1 was converted into compound K via interaction with the enzyme secreted by ¥â-glucosidase active bacteria, Leuconostoc citreum LH1, extracted from kimchi. The optimum time for the conversion of Rb1 to compound K was about 72 hrs at a constant pH of 6.0 and an optimum temperature of about 30¨¬C. Under optimal conditions, ginsenoside Rb1 was decomposed and converted into compound K by 72 hrs post-reaction (99 percent). Both TLC and HPLC were used to analyze the enzymatic reaction. Ginsenoside Rb1 was consecutively converted to ginsenoside Rd, F2, and compound K via the hydrolyses of 20-C ¥â-(1 ¡æ 6)-glucoside, 3-C ¥â-(1 ¡æ 2)glucoside, and 3-C ¥â-glucose of ginsenoside Rb1.
Asunto(s)
Cromatografía , Enzimas Reparadoras del ADN/análisis , Técnicas In Vitro , Leuconostoc/enzimología , Leuconostoc/aislamiento & purificación , Panax/enzimología , Estructuras de las PlantasRESUMEN
INTRODUCTION: Methylation of the promoter of the MGMT gene and MGMT protein expression are recognized as predictive markers for response to alkylating chemotherapy in glioblastoma (GB). MATERIAL AND METHODS: We have assessed MGMT methylation with the methylation-specific polymerase chain reaction (MSP) in tumor samples from 70 GB patients and in serum samples from 37 of these patients. We have also assessed MGMT protein expression by immunohistochemical (IHC) analysis in tissue samples from 63 of these patients. RESULTS: We found concordance between MGMT methylation status in tissue and serum (Cohen's Kappa = 0.586; p<0.0001). MSP for detection of non-methylated MGMT promoter in serum showed a sensitivity of 95.4% and a specificity of 60%, while the IHC methylation test showed a low specificity (8.9%). Patients whose MGMT promoter was methylated in tissue attained longer progression-free and overall survival. In the multivariate analysis, serum MGMT promoter methylation emerged as an independent factor for longer progression-free and overall survival. CONCLUSION: Serum-based MGMT methylation analysis offers a promising alternative to tumor-based MGMT analysis in cases where tissue samples are unavailable.
Asunto(s)
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Metilasas de Modificación del ADN/genética , Metilasas de Modificación del ADN/metabolismo , Enzimas Reparadoras del ADN/genética , Enzimas Reparadoras del ADN/metabolismo , Glioblastoma/genética , Glioblastoma/metabolismo , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Adulto , Anciano , Biomarcadores de Tumor/sangre , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Análisis Químico de la Sangre , Neoplasias Encefálicas/sangre , Neoplasias Encefálicas/mortalidad , Metilación de ADN/fisiología , Metilasas de Modificación del ADN/análisis , Metilasas de Modificación del ADN/sangre , Enzimas Reparadoras del ADN/análisis , Enzimas Reparadoras del ADN/sangre , Femenino , Glioblastoma/sangre , Glioblastoma/mortalidad , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Neoplasias/sangre , Neoplasias/genética , Neoplasias/metabolismo , Regiones Promotoras Genéticas/fisiología , Estudios Retrospectivos , Suero/química , Suero/metabolismo , Análisis de Supervivencia , Análisis de Matrices Tisulares , Proteínas Supresoras de Tumor/análisis , Proteínas Supresoras de Tumor/sangreRESUMEN
O6-Methyguanine-DNA methyltransferase (MGMT) repairs DNA damage and acts as a tumor suppressor in normal cells by preventing DNA mutations. Several antibodies against MGMT are used for immunohistochemical assessment of this marker and no universal standard is adopted. We evaluated the immunohistochemical expression of MGMT with 5 commercially available primary antibodies in 59 invasive breast carcinomas. A tissue microarray was constructed using 59 invasive breast carcinoma samples. Five primary antibodies against MGMT were used for immunohistochemistry, including clones MT3.1, SPM287, and MT23.2. Heat-induced antigen retrieval and polymer-based immunohistochemistry were performed. Stains were analyzed by microscopy and automated digital slide technology. qRT-PCR was performed for all tumors. Clone SPM287 had the highest sensitivity (p<0.001), and clone MT3.1 had the lowest sensitivity (p<0.001). Clone MT23.2 generated higher levels of cytoplasmic staining, which was not observed with the other antibodies (p<0.001). Fifty-six samples (94.9%) showed hypoexpression of MGMT compared with normal breast, as measured by qRT-PCR (p<0.001). Only clone SPM287 correlated significantly with the qRT-PCR results (p=0.027). Antibody clone SPM287 is the most sensitive and specific antibody for the immunohistochemical evaluation of MGMT, rendering it a reliable and effective reagent for research and clinical practice in breast cancer.
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Anticuerpos Monoclonales , Biomarcadores de Tumor/análisis , Neoplasias de la Mama/enzimología , Carcinoma Ductal de Mama/enzimología , Metilasas de Modificación del ADN/análisis , Enzimas Reparadoras del ADN/análisis , Inmunohistoquímica/normas , Proteínas Supresoras de Tumor/análisis , Especificidad de Anticuerpos , Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/patología , Femenino , Humanos , Guías de Práctica Clínica como Asunto , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sensibilidad y Especificidad , Análisis de Matrices TisularesRESUMEN
Enzyme application in biotechnological and environmental processes has had increasing interest due to its efficiency, selectivity and mainly for being environmentally healthful, but these applications require a great volume of enzymes. In this work the effect of different concentrations of ethanol and 2,5 - xylidine on growth and production of laccase by Pycnoporus sanguineus was investigated. In a medium containing 200 mg.L-1 of 2,5 - xylidine or 50 g.L-1 of ethanol, the maximum activity of laccase was 2019 U.L-1 and 1035 U.L-1, respectively. No direct correlation between biomass and activity of laccase was observed for any of the inducers used during the tests. Ethanol concentrations, larger than or equal to 20 g.L-1, inhibited the radial growth of P. sanguineus. This study showed that ethanol, which has less toxicity and cost than the majority of the studied inducers, presents promising perspectives for laccase production by P. sanguineus.
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Biomasa , Enzimas Reparadoras del ADN/análisis , Etanol/análisis , Hongos/enzimología , Hongos/genética , Técnicas In Vitro , Lacasa/análisis , Activación Enzimática , Métodos , Fenómenos Biológicos , MétodosRESUMEN
The aim of this investigation was to evaluate clinicopathologic and immunohistochemical characteristics of synchronous primary gastric adenocarcinomas. Immunohistochemistry for p53 (suppressor pathway) and for hMLH1, hMSH2, and hMSH6 (mutator pathway) was performed using ABC-technique amplification by biotinylated tyramide. Synchronous primary gastric adenocarcinomas were detected in 19/553 (3.43%) of the patients. The tumors were localized in distal stomach in 22, body in 14, and proximal in five. There was a predominance of intestinal type in the group of synchronic tumors compared to the solitary lesions, 73.2 vs 37.3%, p = 0.001. Synchronous neoplasias were diagnosed in earlier stage than solitary neoplasias, T1-T2 = 60.9% vs T1-T2 = 28.4%, p = 0.0001; and N0 = 68.4% vs N0 = 26.2%, p = 0.001. p53 was detected in 52.6% of the patients with synchronous tumors. Altered hMLH1 immunoexpression occurred in 26.3% of the patients and hMSH6 in 5.3%. hMSH2 immunoreactivity was positive in all tumors. p53 was solely detected in 17 tumors, while hMLH1 was altered in 10/24 negative p53 tumors, p = 0.01. Synchronous gastric adenocarcinomas presented higher frequency of intestinal type and early gastric cancer in comparison to solitary gastric cancer. Two routes of carcinogenesis, mutator, and suppressor appear to be involved independently in the development of synchronous tumors.
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Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Neoplasias Primarias Múltiples/metabolismo , Neoplasias Primarias Múltiples/patología , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patología , Proteínas Adaptadoras Transductoras de Señales/análisis , Anciano , Enzimas Reparadoras del ADN/análisis , Proteínas de Unión al ADN/análisis , Femenino , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Homólogo 1 de la Proteína MutL , Proteína 2 Homóloga a MutS/análisis , Proteínas Nucleares/análisis , Proteína p53 Supresora de Tumor/análisisRESUMEN
The Bacillus subtilis enzymes ExoA and Nfo (originally termed YqfS) are endonucleases that can repair apurinic/apyrimidinic (AP) sites and strand breaks in DNA. We have analyzed how the lack of ExoA and Nfo affects the resistance of growing cells and dormant spores of B. subtilis to a variety of treatments, some of which generate AP sites and DNA strand breaks. The lack of ExoA and Nfo sensitized spores (termed alpha-beta-) lacking the majority of their DNA-protective alpha/beta-type small, acid-soluble spore proteins (SASP) to wet heat. However, the lack of these enzymes had no effect on the wet-heat resistance of spores that retained alpha/beta-type SASP. The lack of either ExoA or Nfo sensitized wild-type spores to dry heat, but loss of both proteins was necessary to sensitize alpha-beta- spores to dry heat. The lack of ExoA and Nfo also sensitized alpha-beta-, but not wild-type, spores to desiccation. In contrast, loss of ExoA and Nfo did not sensitize growing cells or wild-type or alpha-beta- spores to hydrogen peroxide or t-butylhydroperoxide. Loss of ExoA and Nfo also did not increase the spontaneous mutation frequency of growing cells. exoA expression took place not only in growing cells, but also in the forespore compartment of the sporulating cell. These results, together with those from previous work, suggest that ExoA and Nfo are additional factors that protect B. subtilis spores from DNA damage accumulated during spore dormancy.
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Bacillus subtilis/enzimología , Proteínas Bacterianas/fisiología , ADN Bacteriano/metabolismo , Endonucleasas/fisiología , Esporas Bacterianas/genética , Bacillus subtilis/genética , Proteínas Bacterianas/genética , Recuento de Colonia Microbiana , Daño del ADN/genética , Enzimas Reparadoras del ADN/análisis , Enzimas Reparadoras del ADN/genética , Enzimas Reparadoras del ADN/fisiología , Endonucleasas/análisis , Endonucleasas/genética , Eliminación de Gen , Expresión Génica , Calor , Peróxido de Hidrógeno/toxicidad , Mutación , Esporas Bacterianas/fisiología , terc-Butilhidroperóxido/toxicidadRESUMEN
OBJECTIVE: Considering that hMSH2, hMLH1 and p53 are important in maintaining genomic stability of the oral mucosa epithelium, the purpose of the present study was to investigate the immunolocalization of these proteins in the epithelium of the oral mucosa of patients submitted to bone marrow transplantation (BMT) compared with controls. MATERIALS AND METHODS: Twenty-one samples of lip biopsies from BMT recipients were retrieved. Twenty samples of normal lower labial mucosa associated with mucocele in non-transplanted patients were included as control group. The streptavidin-biotin complex stain was used to detect the human DNA mismatch repair proteins hMSH2, hMLH1 and p53 protein. RESULTS: The main findings demonstrated that the mean number of suprabasal epithelial cells positive for MSH2 was statistically higher than the control group. The immunostaining of hMLH1 and p53 at the basal and suprabasal epithelial layers were statistically higher in the oral labial mucosa of the BMT patients compared with controls. CONCLUSION: The present study shows that oral epithelial cells of BMT patients show increased immunolocalization of the DNA repair related proteins.