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BACKGROUND: Histologic features of idiopathic non-cirrhotic portal hypertension (INCPH) may overlap with those without INCPH. Recently, these features have been recognized as part of the larger spectrum of porto-sinusoidal vascular disease (PSVD). We assessed interobserver agreement on histologic features that are commonly associated with INCPH and studied whether a provision of relevant clinical history improves interobserver agreement. METHODS: The examined histologic features include lobular (such as anisocytosis, nodular regeneration, sinusoidal dilatation, increased parenchymal draining veins, and incomplete fibrous septa) and portal tract changes (such as paraportal shunting vessel(s), portal tract remnant, increased number of portal vessels, and obliterative portal venopathy). Thirty-four archived liver samples from patients with (group A) and without (group B) INCPH were retrieved. A total of 90 representative images of lobules (L) and portal tracts (P) were distributed among 9 liver pathologists blinded to true clinical history. Each pathologist answered multiple choice questions based on the absence (Q1) or presence (Q2) of clinical history of portal hypertension. Fleiss' kappa coefficient analysis (unweighted) was performed to assess interobserver agreement on normal versus abnormal diagnosis, in L and P, based on Q1 and Q2. RESULTS: The kappa values regarding normal versus abnormal diagnosis were 0.24, 0.24, 0.18 and 0.18 for L-Q1, L-Q2, P-Q1, and P-Q2, respectively. With true clinical history provided, the kappa values were L- 0.32, P-0.17 for group A and L-0.12, P-0.14 for group B. Four pathologists changed their assessments based on the provided history. Interobserver agreement on the interpretation of L and P as normal versus abnormal was slight to fair regardless of provision of clinical history. CONCLUSIONS: Our findings indicate that the histologic features of INCPH/PSVD are not limited to patients with portal hypertension and are subject to significant interobserver variation.
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Hipertensión Portal/diagnóstico , Hipertensión Portal/patología , Adolescente , Adulto , Anciano , Femenino , Humanos , Cirrosis Hepática/patología , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Patólogos , Adulto JovenRESUMEN
BACKGROUND: Phlebotomy induces regression of liver fibrosis in genetic hemochromatosis. We assessed the histologic changes in pre-phlebotomy and post-phlebotomy liver biopsies from patients with HFE mutation as a model to study regression of fibrosis. We aimed to show that phlebotomy-induced histologic lesions overlap with porto-sinusoidal vascular disease (PSVD, also known as idiopathic non-cirrhotic portal hypertension), histologically. METHODS: A total of 51 biopsies (22 pre-phlebotomy and 29 post-phlebotomy) were reviewed, and three variables were studied: iron index indicative of the amount of accumulated iron (range 0 to 18), the combined score of vascular changes reflecting the presence of histological lesions that are described in PSVD (range 0 to 9) and the high-grade shunt vessel by calculating the proportion of portal tracts with shunt vessels, with a cutoff of 50%. Two-tailed Student's t-test and Fisher's exact test were performed to compare the means of two variables and frequencies of the histologic lesions in two groups, respectively. A P-value < 0.05 was considered statistically significant. RESULTS: The iron index was higher in the pre-phlebotomy compared to post-phlebotomy group (P = 0.01). Compared to the pre-phlebotomy group, the combined score was higher in the post-phlebotomy group when the cases of advanced fibrosis were excluded (P = 0.023) and remained higher when patients with risk factors for PSVD were further excluded (P = 0.034). The high-grade shunt vessel tended to be more common in the post-phlebotomy group when advanced fibrosis was excluded; however, the statistical significance was marginal (P = 0.056). CONCLUSIONS: Phlebotomy reduces hepatic iron load and induces histologic lesions of PSVD in patients with HFE mutation. Our data support a postulation that some of the histologic lesions of PSVD represent vascular remodeling following a regression of fibrosis and may not be reflective of risk factors or etiopathogenesis of PSVD. Regressed fibrosis and PSVD may not be reliably distinguished in a limited sample, therefore warranting cautious interpretation in the right clinical context.
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Human T-cell lymphotropic virus (HTLV) is a human oncoretrovirus known to cause adult T-cell leukaemia/lymphoma (ATLL). Coinfection of human T-lymphotropic virus type 1 with Epstein-Barr virus (EBV) results in enhanced expression of the HTLV virus and leads to aggressive organ involvement from T-cell malignancy. It has also been observed that the prevalence of hepatitis B infection has been higher in patients with HTLV ATLL as compared with the general population in certain countries. We describe a case of a 34-year-old man who initially presented with leucocytosis, fatigue and conjunctival erythema. His radiological images revealed significant generalised adenopathy, and his flow cytometry analysis came back positive for CD4-positive T-cell lymphoma. He was subsequently diagnosed with HTLV-positive ATLL. Ultimately the patient was also diagnosed with acute hepatitis B and EBV. We describe a unique case of ATLL with coinfection with two other viruses, the association of which can be of potential prognostic value in guiding the treatment strategies for ATLL.
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Infecciones por Virus de Epstein-Barr/complicaciones , Infecciones por HTLV-I/complicaciones , Hepatitis B/complicaciones , Leucemia-Linfoma de Células T del Adulto/virología , Adulto , Coinfección/virología , Virus de la Hepatitis B/aislamiento & purificación , Herpesvirus Humano 4/aislamiento & purificación , Virus Linfotrópico T Tipo 1 Humano/aislamiento & purificación , Humanos , Leucemia-Linfoma de Células T del Adulto/etiología , Leucemia-Linfoma de Células T del Adulto/patología , MasculinoRESUMEN
PURPOSE: Quantification of calretinin-stained mucosal nerve fibers by image processing and analysis (IPA) may objectively define the transition zone (TZ) of Hirschsprung disease (HD). We tested the utility of IPA as an adjunctive tool in HD. MATERIALS AND METHODS: Calretinin immunostain was performed on 15 HD pull-through specimens, and multiple images were captured from the proximal aganglionic zone, TZ, and probable normal zone (NZ). Pixel count (PC), defined as the percentage of brown-stained pixels in the mucosa, was quantified and plotted against distance from the rectal distal end. To validate the method, PCs from 45 images were compared with three-tiered visual scoring by five pathologists. Results were correlated against pertinent variables, which were retrieved from the clinical record. RESULTS: The PC gradually increased in the TZ toward the proximal resection margin in 10/13 (77%) cases. The PC variation in the probable NZ and around the circumference was substantial by the coefficient of variation. The mean PC of images with a visual score of 1 was less than scores of 2 and 3 by all five (100%) pathologists (p < 0.01). One patient had possible TZ pull-through that was clinically confirmed. CONCLUSION: While the mucosal calretinin staining gradually increases in the TZ, for now, the boundaries of the TZ cannot be accurately defined by mucosal biopsies given the substantial variation of staining around the circumference at the same distance and in the NZ. However, the IPA technique does provide a continuous variable and warrants further utility in HD studies.
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Calbindina 2/metabolismo , Colon/metabolismo , Enfermedad de Hirschsprung/diagnóstico , Interpretación de Imagen Asistida por Computador/métodos , Mucosa Intestinal/metabolismo , Biomarcadores/metabolismo , Colon/patología , Femenino , Enfermedad de Hirschsprung/metabolismo , Enfermedad de Hirschsprung/patología , Humanos , Inmunohistoquímica , Lactante , Recién Nacido , Mucosa Intestinal/patología , Masculino , Proyectos Piloto , Estudios Retrospectivos , Coloración y EtiquetadoRESUMEN
Although nuclear immunostaining for paired box protein (PAX5) is widely used in practice, its cytoplasmic localization has not been evaluated. Recently we encountered cytoplasmic granular PAX5 staining in rectal well-differentiated neuroendocrine tumor (WD-NET) in the absence of nuclear staining. We investigated the specificity of this staining pattern for rectal NET (n=21) in comparison with 108 NETs, 1 WD rectal NET with elevated proliferation (WD-NET G3), and 40 poorly differentiated neuroendocrine carcinomas from the gastrointestinal and pancreatobiliary tract and liver. Representative tumor sections were subject to immunohistochemical stain for PAX5 antibody. Immunohistochemistry for 3 L-cell markers, glucagon-like peptide 1 and 2, and peptide YY, was performed on all rectal and appendiceal NETs and all other NETs with cytoplasmic PAX5 staining. Cytoplasmic PAX5 staining was observed in 90% (19/21) of rectal NET, 27% (3/11) of appendiceal, 14% (2/14) of pancreatic, 7% (2/29) of lung, 25% (3/12) metastatic NET in the liver, and 100% (1/1) of renal NET. No PAX5 cytoplasmic staining was seen in all grades of NET in other organs, rectal WD-NET G3, and all neuroendocrine carcinoma. L-cell marker staining was observed in all 21 (100%) rectal, in 3 of 3 (100%) PAX5-positive, and 1 of 7 (14%) PAX5-negative appendiceal NET. Cytoplasmic PAX5 staining is specific for rectal carcinoids. The sensitivity and specificity of PAX5 to detect L-cell type rectal carcinoids is 90% (19/21) and 100% (21/21), respectively. Cytoplasmic localization of the PAX5 protein may be utilized as a surrogate marker to detect L-cell type rectal carcinoids.
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Biomarcadores de Tumor/metabolismo , Citoplasma/metabolismo , Tumores Neuroendocrinos/metabolismo , Factor de Transcripción PAX5/metabolismo , Neoplasias del Recto/metabolismo , Adolescente , Adulto , Diferenciación Celular , Niño , Femenino , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Tumores Neuroendocrinos/diagnóstico , Valor Predictivo de las Pruebas , Pronóstico , Neoplasias del Recto/diagnóstico , Sensibilidad y Especificidad , Adulto JovenRESUMEN
Microscopic ileitis has been infrequently reported in the literature with the few reported cases usually associated with concurrent microscopic colitis. Having encountered a case of collagenous ileitis involving the diverted distal limb of a loop ileostomy and sparing the proximal limb, we examined additional cases of loop ileostomy, end ileostomy, colostomy, and the accompanying diverted colorectal segment for features of microscopic ileitis and colitis. A total of 101 cases of diverted and nondiverted enteric segments were examined from 37 loop ileostomies, 16 end ileostomies, and 12 colostomies status post-Hartmann's procedure. The patients' clinical histories, including demographics and risk factors for microscopic colitis, were obtained from electronic medical records. The index case and an additional case showed collagenous ileitis: the former in the diverted distal limb, and the latter in the nondiverted proximal limb of the loop ileostomy. The latter was associated with high ileostomy output with watery diarrhea. Two additional cases showed lymphocytic ileitis: one in the nondiverted proximal limb of loop ileostomy and the other in the end ileostomy. All 4 patients had one or more risk factors for microscopic colitis. The etiology of microscopic ileitis seems to be multifactorial, and microscopic ileitis may be underdiagnosed. The diverted enteric segment may be involved by microscopic enteritis, suggesting that additional factors other than fecal stasis and altered bacterial flora may be contributing to its pathogenesis. When microscopic ileitis is encountered, identifying associated risk factors, recognizing incipient clinical symptoms of microscopic colitis, and considering other associated diseases or conditions are warranted.
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Colitis/patología , Diarrea/patología , Ileítis/patología , Ileostomía , Intestino Delgado/patología , Adolescente , Adulto , Anciano , Niño , Preescolar , Colitis/diagnóstico , Colitis/etiología , Colostomía/métodos , Diarrea/diagnóstico , Femenino , Humanos , Ileítis/diagnóstico , Ileítis/etiología , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/patología , Adulto JovenRESUMEN
Paired Box 5 (PAX5), a well-established B-cell marker, is preferentially expressed in small cell lung carcinoma and regulates the transcription of c-Met, offering a potential for therapeutic target. Its expression in poorly differentiated neuroendocrine carcinoma (PDNEC) of the digestive system has not been systemically evaluated. Archived pathology materials from 38 PDNEC in the gastrointestinal (GI) and pancreatobiliary (PB) tract were reviewed. Representative tumor sections were subject to immunohistochemical stain for PAX5, c-Met, and CD20. The extent of the staining [focal (<10%), patchy (10% to 50%), and diffuse (>50%)] and intensity (1+ to 3+) was evaluated. In total, 38 cases of well-differentiated neuroendocrine tumors from GI/PB tract served as controls. Nuclear PAX5 staining was observed in 16 (42%) cases in total, in 46% (11/24) of large cell neuroendocrine carcinoma, 67% (4/6) of small cell neuroendocrine carcinoma, and 13% (1/8) of mixed adenoneuroendocrine carcinoma, with diffuse (8), patchy (4), or focal (4) staining. The intensity was 3+ (2), 2+ (6), and 1+ (8). PAX5 expression was common in ampullary (4/5) and gastroesophageal junctional/esophageal (5/9) PDNEC. Two (5%) of 38 well-differentiated neuroendocrine tumors were positive for PAX5. Three PAX5 positive PDNEC showed weak cytoplasmic c-Met immunolabeling. CD20 was negative in all tumors. Our data show that PAX5 is commonly expressed in PDNEC of the GI/PB tract including small cell neuroendocrine carcinoma. This observation warrants a cautious approach when interpreting small biopsy of poorly differentiated neoplasms, especially when lymphoma is considered in the differentials. Further study of PAX5/c-Met signaling pathway and its potential therapeutic value in GI/PB PDNEC is warranted.
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Adenocarcinoma , Carcinoma de Células Grandes , Carcinoma Neuroendocrino , Carcinoma de Células Pequeñas , Neoplasias del Sistema Digestivo , Regulación Neoplásica de la Expresión Génica , Proteínas de Neoplasias/biosíntesis , Factor de Transcripción PAX5/biosíntesis , Adenocarcinoma/diagnóstico , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Adenocarcinoma/terapia , Anciano , Anciano de 80 o más Años , Biopsia , Carcinoma de Células Grandes/diagnóstico , Carcinoma de Células Grandes/metabolismo , Carcinoma de Células Grandes/patología , Carcinoma de Células Grandes/terapia , Carcinoma Neuroendocrino/diagnóstico , Carcinoma Neuroendocrino/metabolismo , Carcinoma Neuroendocrino/patología , Carcinoma Neuroendocrino/terapia , Carcinoma de Células Pequeñas/metabolismo , Carcinoma de Células Pequeñas/patología , Carcinoma de Células Pequeñas/terapia , Neoplasias del Sistema Digestivo/diagnóstico , Neoplasias del Sistema Digestivo/metabolismo , Neoplasias del Sistema Digestivo/patología , Neoplasias del Sistema Digestivo/terapia , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: Idiopathic noncirrhotic portal hypertension (INCPH) is associated with histologic changes secondary to obliterative portal venopathy without cirrhosis. We studied the prevalence of individual histological features of INCPH in liver biopsies obtained incidentally during unrelated elective procedures and in elective liver biopsies with the diagnosis of fatty liver disease. METHODS: A total of 53 incidental liver biopsies obtained intraoperatively during unrelated elective procedures and an additional 28 elective biopsies with the diagnosis of fatty liver disease without portal hypertension and cirrhosis were studied. Various histologic features of INCPH were evaluated. RESULTS: Shunt vessel (30%), phlebosclerosis (27%), increased number of portal vessels (19%) and incomplete septa (17%) were common in these liver biopsies after confounding factors such as co-existing fatty liver disease or fibrosis were excluded. At least one feature of INCPH was noted in 90% of the biopsies. Eight (10%) biopsies showed 5-6 features of INCPH. In total, 11 (14%) of 81 patients had risk factors associated with INCPH, including hypercoagulability, autoimmune disease, exposure to drugs, and infections. No patient had portal hypertension at the end of the follow-up. CONCLUSION: The histologic features of INCPH are seen in incidental liver biopsies and fatty liver disease without portal hypertension. Ten percent of the biopsies show 5-6 features of INCPH without portal hypertension. Interpreting histologic features in the right clinical context is important for proper patient care.
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Hipertensión Portal/epidemiología , Cirrosis Hepática/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biopsia , Femenino , Humanos , Hipertensión Portal/diagnóstico , Hipertensión Portal/patología , Masculino , Persona de Mediana Edad , New York/epidemiología , Prevalencia , Estudios Retrospectivos , Adulto JovenRESUMEN
The conventional histologic grading of colorectal cancer (CRC) is less suited for resected rectal cancer following neoadjuvant chemoradiation. Enumeration of poorly differentiated clusters (PDC) is a recently proposed histologic grading scheme. We aimed to apply PDC grading to treated rectal cancer and to test the prognostic significance of this novel approach. Archived hematoxylin and eosin slides of 72 rectal adenocarcinomas resected following neoadjuvant treatment were retrieved. PDC, tumor budding, and tumor regression were assessed. The parameters were correlated with clinicopathological features and survival. PDC was strongly associated with tumor budding, perineural invasion (PNI), metastasis, and low degree of tumor regression. Tumor budding was significantly associated with lymphovascular invasion and PNI, and metastasis. Tumors with a lower degree of regression were more likely to show high pathologic T stage and advanced clinical stage. Local recurrence was associated with poor survival. PDC did not correlate with overall survival. PDC grading is applicable to resected rectal cancer status post neoadjuvant treatment and correlates with established histopathological prognosticators. PDC and tumor budding may represent a histologic spectrum reflective of the same biological significance. Validation and incorporation of these simple histologic grading schemes may strengthen the prognostic power of the histologic parameters that influence the oncologic outcome in treated rectal cancer. Further study to evaluate the significance of PDC as an oncologic prognosticator is warranted.
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Neoplasias del Recto/diagnóstico , Neoplasias del Recto/mortalidad , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores , Toma de Decisiones Clínicas , Manejo de la Enfermedad , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Metástasis de la Neoplasia , Estadificación de Neoplasias , Pronóstico , Neoplasias del Recto/cirugíaRESUMEN
Mitochondria play critical roles in oxidative phosphorylation and energy metabolism. Increasing evidence supports that mitochondrial DNA (mtDNA) damage and dysfunction play vital roles in the development of many mitochondria-related diseases, such as obesity, diabetes mellitus, infertility, neurodegenerative disorders, and malignant tumors in humans. Human 8-oxoguanine-DNA glycosylase 1 (hOGG1) transgenic (TG) mice were produced by nuclear microinjection. Transgene integration was analyzed by PCR. Transgene expression was measured by RT-PCR and Western blot analysis. Mitochondrial DNA damage was analyzed by mutational analyses and measurement of mtDNA copy number. Total fat content was measured by a whole-body scan using dual-energy X-ray absorptiometry. The hOGG1 overexpression in mitochondria increased the abundance of intracellular free radicals and major deletions in mtDNA. Obesity in hOGG1 TG mice resulted from increased fat content in tissues, produced by hyperphagia. The molecular mechanisms of obesity involved overexpression of genes in the central orexigenic (appetite-stimulating) pathway, peripheral lipogenesis, down-regulation of genes in the central anorexigenic (appetite-suppressing) pathway, peripheral adaptive thermogenesis, and fatty acid oxidation. Diffuse hepatosteatosis, female infertility, and increased frequency of malignant lymphoma were also seen in these hOGG1 TG mice. High levels of hOGG1 expression in mitochondria, resulting in enhanced oxidative DNA damage processing, may be an important factor in human metabolic syndrome, infertility, and malignancy.
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ADN Glicosilasas/genética , Hígado Graso/patología , Hígado/patología , Mitocondrias/metabolismo , Obesidad/metabolismo , Oxígeno/metabolismo , Animales , Glucemia/metabolismo , Daño del ADN , ADN Mitocondrial/genética , Femenino , Eliminación de Gen , Ratones , Ratones Transgénicos , Obesidad/genética , Oxígeno/química , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
PURPOSE: To test the hypothesis that cardiac morphologic differences between Ames dwarf and wild-type littermates might correlate with the increased longevity observed in the Ames dwarf mice. METHODS: Hearts removed from young adult (5-7 mo) and old (24-28 mo) Ames dwarf and wild-type littermates underwent histological and morphometric analysis. Measurements of cell size, nuclear size, and collagen content were made using computerized color deconvolution and particle analysis methodology. RESULTS: In the young mice at six months of age, mean cardiomyocyte area was 46% less in Ames dwarf than in wild-type mice (p<0.0001). Cardiomyocyte size increased with age by about 52% in the wild-type mice and 44% in the Ames dwarf mice (p<0.001). There was no difference in nuclear size of the cardiomyocytes between the young adult wild-type and Ames dwarf mice. There was an age-associated increase in the cardiomyocyte nuclear size by approximately 50% in both the Ames and wild-type mice (p<0.001). The older Ames dwarf mice had slightly larger cardiomyocyte nuclei compared to wild-type (2%, p<0.05). The collagen content of the hearts in young adult Ames dwarf mice was estimated to be 57% less compared to wild-type littermates (p<0.05). Although collagen content of both Ames dwarf and wild-type mouse hearts increased with age, there was no significant difference at 24 months. CONCLUSIONS: In wild-type and Ames dwarf mice, nuclear size, cardiomyocyte size, and collagen content increased with advancing age. While cardiomyocyte size was much reduced in young and old Ames dwarf mice compared with wild-type, collagen content was reduced only in the young adult mice. Taken together, these findings suggest that Ames dwarf mice may receive some longevity benefit from the reduced cardiomyocyte cell size and a period of reduced collagen content in the heart during adulthood.
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Colágeno/metabolismo , Longevidad , Miocardio/citología , Factores de Edad , Animales , Núcleo Celular/ultraestructura , Tamaño de la Célula , Corazón/anatomía & histología , Ratones , Ratones Endogámicos , Miocardio/ultraestructura , Tamaño de los ÓrganosRESUMEN
OBJECTIVE: The study is designed to elucidate the relationship between epigenetic silencing of the hMLH1 (human MutL homologue 1) gene and microsatellite instability (MSI) and the prognostic values of hMLH1 promoter methylation and MSI in head and neck squamous cell carcinoma (HNSCC). STUDY DESIGN: Cross-sectional study. SETTING: Tertiary referral center. SUBJECTS AND METHODS: A total of 120 cases of HNSCC were analyzed for hMLH1 promoter hypermethylation, protein expression, and MSI by using methylation-specific polymerase chain reaction, immunohistochemical staining, and polymerase chain reaction amplification with the use of 16 fluorescent-labeled microsatellite markers, followed by fragment analysis. RESULTS: Of 120 HNSCCs, hMLH1 promoter hypermethylation and decreased hMLH1 protein expression were shown in 39 (32.5%) and 22 (18.3%), respectively. hMLH1 promoter hypermethylation was detected in 13 of 52 (25%) normal-appearing squamous mucosa adjacent to invasive carcinoma. MSI was detected in 21 (17.5%) tumors at two or more markers and in 99 (82.5%) tumors with no evidence of MSI or at only one marker. Hypermethylation of the hMLH1 gene is significantly associated with decreased hMLH1 protein expression (P < 0.001). High-frequency MSI was significantly associated with promoter hypermethylation (P = 0.01) but not with decreased protein expression (P = 0.069) of hMLH1 gene. hMLH1 promoter hypermethylation is significantly associated with decreased cause-specific survival for HNSCC patients (P = 0.03). CONCLUSIONS: Promoter hypermethylation of the hMLH1 gene could be detected early in head and neck squamous carcinogenesis and may be associated with increased MSI and poor survival in HNSCC.
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Proteínas Adaptadoras Transductoras de Señales/genética , Carcinoma de Células Escamosas/genética , Silenciador del Gen , Neoplasias de Cabeza y Cuello/genética , Inestabilidad de Microsatélites , Proteínas Nucleares/genética , Proteínas Adaptadoras Transductoras de Señales/biosíntesis , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/mortalidad , Metilación de ADN , Femenino , Neoplasias de Cabeza y Cuello/metabolismo , Neoplasias de Cabeza y Cuello/mortalidad , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Homólogo 1 de la Proteína MutL , Proteínas Nucleares/biosíntesis , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas/genética , Análisis de Supervivencia , Tasa de SupervivenciaRESUMEN
HYPOTHESIS: The purpose of this animal study was to confirm the presence of all three atrial natriuretic peptide (ANP) receptor subtypes in the rat inner ear and compare the expression of each receptor after inner ear injection of ANP, phosphate-buffered saline, or a solution containing ANP incubated with anti-ANP antibody (to block upregulation). BACKGROUND: Receptors for ANP and related compounds have been localized in the inner ear of animals and humans. A previous study at this institution demonstrated the ability to up-regulate the expression of the three ANP receptors (ANP-A, ANP-B, ANP-C) in response to round window injection of ANP in the rat inner ear. METHODS: After surgical exposure, the round window of female Lewis rats was injected with various concentrations of ANP, ANP plus anti-ANP antibody, or control. Animals were killed 24 hours after injection, inner ear tissues were harvested and homogenized, and RNA was isolated for reverse-transcription polymerase chain reaction. RESULTS: Electrophoresis showed the presence of all three receptor subtypes with exposure to phosphate-buffered saline. Expression was significantly higher 24 hours after injection with the two concentrations of ANP. This increase was partially blocked with increasing relative concentrations of anti-ANP antibody. CONCLUSIONS: These findings confirm the presence and responsiveness of ANP receptors in the rat inner ear. The ability to block up-regulation with the antibody provides a potential new research tool for manipulating the function of this hormone system in experimental models and, ultimately, in understanding the mechanisms of fluid homeostasis in the inner ear.
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Factor Natriurético Atrial/farmacología , Oído Interno/efectos de los fármacos , Oído Interno/metabolismo , Receptores del Factor Natriurético Atrial/metabolismo , Animales , Anticuerpos/farmacología , Factor Natriurético Atrial/administración & dosificación , Factor Natriurético Atrial/inmunología , Tampones (Química) , Relación Dosis-Respuesta a Droga , Combinación de Medicamentos , Electroforesis en Gel de Agar , Femenino , Inyecciones , Fosfatos , Isoformas de Proteínas/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Endogámicas Lew , Receptores del Factor Natriurético Atrial/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Ventana Redonda , Cloruro de Sodio/química , Cloruro de Sodio/farmacología , Factores de Tiempo , Regulación hacia Arriba/efectos de los fármacosRESUMEN
BACKGROUND: Alkylating N-nitroso compounds can interact directly with DNA, forming O(6)-alkylguanine, a DNA adduct proved to be mutagenic and carcinogenic if not sufficiently repaired. A specific DNA repair enzyme, O(6)-methylguanine-DNA methyltransferase (MGMT), can remove the alkyl group from the O(6)-position of the guanine, thereby preventing its mutagenic and carcinogenic effects. Inactivation of the MGMT gene in association with promoter hypermethylation results in persistence of O(6)-alkylguanine in DNA, leading to G:C to A:T transition mutation and these G:C to A:T transition mutations can inactivate p53 tumor suppressor gene or activate ras proto-oncogene. METHODS: We analyzed MGMT promoter hypermethylation and protein expression patterns in 94 cases of primary head and neck squamous cell carcinoma (HNSCC) by methylation-specific PCR (MSP) and immunohistochemical staining. The results were then correlated with clinical follow-up data. RESULTS: MGMT promoter hypermethylation was present in 17 of 94 patients (18.1%) and apparent loss of protein expression was seen in 19 of 93 HNSCC patients (20.4%). The presence of MGMT promoter hypermethylation was significantly correlated with loss of MGMT protein expression in HNSCC. Both MGMT promoter hypermethylation and loss of protein expression were significantly correlated to increased tumor recurrences and decreased patient survival, independent of other risk factors, such as tumor site, tumor size, nodal status, age, and chemoradiation therapy. CONCLUSIONS: MGMT promoter hypermethylation and apparent loss of protein expression are reliable and independent prognostic factors in HNSCC. The above study may also provide guideline or basis for applying alkylating antitumor agents to patients with HNSCC that display MGMT promoter hypermethylation and/or loss of MGMT protein expression.
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Carcinoma de Células Escamosas/genética , Enzimas Reparadoras del ADN/genética , Silenciador del Gen , Neoplasias de Cabeza y Cuello/genética , O(6)-Metilguanina-ADN Metiltransferasa/genética , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Escamosas/enzimología , Aductos de ADN , Metilación de ADN , Guanina/metabolismo , Neoplasias de Cabeza y Cuello/enzimología , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Pronóstico , Regiones Promotoras Genéticas , Proto-Oncogenes Mas , Factores de Riesgo , Análisis de SupervivenciaRESUMEN
The Ataxia-telangiectasia-mutated (ATM) gene product is a well-characterized tumor suppressor that plays a key role in maintenance of genomic stability. We have recently documented that the ATM promoter is a target for epigenetic silencing in cultured tumor cells. Here we show that aberrant methylation of the ATM promoter occurs in a significant percentage (25%) of head and neck squamous cell carcinomas. The presence of methylated ATM promoter shows a statistically significant correlation with an earlier age of initial diagnosis and decreased overall survival, particularly in early-stage tumors. These findings indicate that ATM promoter hypermethylation occurs in head and neck squamous cell carcinoma, and this feature is a potentially useful prognostic marker in this tumor type.
Asunto(s)
Ataxia Telangiectasia/genética , Carcinoma de Células Escamosas/genética , Neoplasias de Cabeza y Cuello/genética , Regiones Promotoras Genéticas/genética , Anciano , Secuencia de Bases , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/patología , Neoplasias de Cabeza y Cuello/mortalidad , Neoplasias de Cabeza y Cuello/patología , Humanos , Masculino , Metilación , Persona de Mediana Edad , Pronóstico , Regiones Promotoras Genéticas/fisiología , Análisis de SupervivenciaRESUMEN
E-cadherin is a calcium-dependent, intercellular adhesion molecule that is specifically expressed in epithelial tissues and plays an important role in maintaining epithelial stability. E-cadherin is widely regarded as a prognostic marker in many types of human cancers. The inactivation of the E-cadherin gene is linked to increased potential for tumor invasiveness and distant metastasis. We previously demonstrated reduced expression of E-cadherin protein immunohistochemically in invasive squamous cell carcinomas of the skin as compared with adjacent normal skin. An epigenetic alteration in association with promoter hypermethylation is one important mechanism of gene silencing. In the present study, we analyze the E-cadherin gene promoter hypermethylation in preneoplastic and neoplastic skin lesions to determine whether epigenetic alteration of the E-cadherin gene also plays an important role in cutaneous squamous carcinogenesis. A total of 33 cases was examined for evidence of E-cadherin promoter hypermethylation, and these consist of nine cases of spongiotic dermatitis as nonneoplastic skin control, nine cases of actinic keratosis, eight cases of squamous cell carcinoma in situ, and seven cases of invasive squamous cell carcinoma. Promoter hypermethylation of the E-cadherin gene was detected in 6 of 7 cases (85%) of invasive squamous cell carcinoma, 4 of 8 cases (50%) of squamous cell carcinoma in situ, 4 of 9 cases (44%) of actinic keratosis, and 2 of 9 cases (22%) of nonneoplastic skin. We conclude that E-cadherin promoter hypermethylation occurs frequently and may represent an important mechanism of E-cadherin inactivation in cutaneous preneoplastic and neoplastic lesions. The frequencies of E-cadherin promoter hypermethylation appear to be correlated with more advanced stage of squamous carcinogenesis in skin.
Asunto(s)
Cadherinas/genética , Carcinoma in Situ/genética , Carcinoma de Células Escamosas/genética , Metilación de ADN , Queratosis/genética , Neoplasias Cutáneas/genética , Carcinoma in Situ/patología , Carcinoma de Células Escamosas/patología , Cartilla de ADN/química , ADN de Neoplasias/análisis , Silenciador del Gen , Humanos , Queratosis/patología , Trastornos por Fotosensibilidad , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas , Neoplasias Cutáneas/patologíaRESUMEN
The p16 (CDKN2a/INK4a) gene is an important tumor-suppressor gene, involved in the p16/cyclin-dependent kinase/retinoblastoma gene pathway of cell cycle control. The p16 protein is considered to be a negative regulator of the pathway. The gene encodes an inhibitor of cyclin-dependent kinases 4 and 6, which regulate the phosphorylation of retinoblastoma gene and the G1 to S phase transition of the cell cycle. In the present study, p16 gene promoter hypermethylation patterns and p16 protein expression were analyzed in 100 consecutive untreated cases of primary head and neck squamous cell carcinoma by methylation-specific PCR and immunohistochemical staining. The p16 promoter hypermethylation and apparent loss of p16 protein expression were detected in 27% and 74% of head and neck squamous cell carcinoma, respectively. By chi(2) test, history of alcohol or tobacco use was significantly correlated with the loss of p16 protein expression (P =.005 and.05, respectively). When patient follow-up data were correlated with various clinical and molecular parameters, tumor size and nodal and clinical stage were the strongest prognostic predictors for disease-free survival (tumor recurrence) and for cause-specific and overall survival in patients with head and neck squamous cell carcinoma. Neither p16 promoter hypermethylation nor apparent loss of p16 protein expression appears to be an independent prognostic factor, although loss of p16 protein may be used to predict overall patient survival in early-stage head and neck squamous cell carcinoma.
Asunto(s)
Biomarcadores de Tumor/análisis , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Genes p16 , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/patología , Adulto , Anciano , Consumo de Bebidas Alcohólicas , Carcinoma de Células Escamosas/mortalidad , Metilación de ADN , ADN de Neoplasias/análisis , Neoplasias de Cabeza y Cuello/mortalidad , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Pronóstico , Regiones Promotoras Genéticas , Factores de Riesgo , FumarRESUMEN
Death-associated protein kinase is a serine/threonine protein kinase implicated in promoting apoptosis and tumor suppression, whereas p16 is a tumor suppressor gene that inhibits cyclin-dependent kinase 4 and 6 activity and arrests the cell cycle in the G1 phase. Hypermethylation of death-associated protein kinase or p16 gene with resultant gene inactivation has been described in a wide variety of human cancers. Promoter methylation of the death-associated protein kinase and p16 gene has been found in about 55% and 30% cases of head and neck squamous cell carcinoma respectively but has not yet been analyzed in cutaneous premalignant and malignant lesions. A total of 33 cases were examined for evidence of death-associated protein kinase and p16 hypermethylation and these consist of 9 cases of spongiotic dermatitis as nonneoplastic skin control, 9 cases of actinic keratosis, 8 cases of squamous cell carcinoma in situ, and 7 cases of invasive squamous cell carcinoma. Death-associated protein kinase promoter methylation was detected in 1 case of squamous cell carcinoma in situ and 1 case of nonneoplastic skin control but none of the cases of invasive squamous cell carcinoma or actinic keratosis. P16 promoter methylation was detected in 1 case of invasive squamous cell carcinoma and 1 case of nonneoplastic skin control but none of the cases of squamous cell carcinoma in situ or actinic keratosis. Promoter hypermethylation of the death-associated protein kinase and p16 genes does not appear to play an important role in the development of cutaneous squamous cell carcinoma. The data thus suggest that the mechanisms of ultraviolet-induced cutaneous carcinomas differ from those involved in the development of head and neck squamous cell carcinoma, a malignant disease induced by tobacco and alcohol exposure.
Asunto(s)
Proteínas Quinasas Dependientes de Calcio-Calmodulina/genética , Carcinoma de Células Escamosas/genética , Metilación de ADN , Genes p16 , Queratosis/genética , Neoplasias Cutáneas/genética , Proteínas Reguladoras de la Apoptosis , Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Carcinoma de Células Escamosas/enzimología , Carcinoma de Células Escamosas/patología , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , ADN de Neoplasias/análisis , Proteínas Quinasas Asociadas a Muerte Celular , Silenciador del Gen , Humanos , Queratosis/enzimología , Queratosis/patología , Trastornos por Fotosensibilidad , Regiones Promotoras Genéticas , Neoplasias Cutáneas/enzimología , Neoplasias Cutáneas/patologíaRESUMEN
Head and neck squamous cell carcinoma (HNSCC) is a multistage process during which adverse genetic alterations accumulate resulting in loss of cell cycle control, selective cell overgrowth, and ultimately formation of malignancy. Among various genetic alterations in HNSCC is increased microsatellite instability (MSI). hMLH1 is one of the major mismatch DNA repair genes, the inactivation of which caused increased MSI in a variety of human cancers including HNSCC. While somatic mutation is a major mechanism of the hMLH1 gene inactivation in hereditary form of human cancer, promoter hypermethylation appears to be primarily involved in the inactivation of the hMLH1 gene in sporadic form of human cancers. In the current study, we analyzed 78 cases of HNSCC for hMLH1 protein expression and promoter hypermethylation by IHC and methylation-specific PCR (MSP). Twenty-four of 78 cases (31%) of HNSCC contained markedly reduced levels of the hMLH1 protein. Based on the IHC results, 8 cases without and 8 with hMLH1 protein expression (total of 16) were further analyzed by MSP. Seven of 8 cases (88%) that were negative for the hMLH1 protein displayed promoter hypermethylation, whereas 7 of 7 cases (100%) strongly positive for the protein were free of promoter methylation. This study confirms our previous conclusion that promoter hypermethylation represents a major mechanism of the hMLH1 gene inactivation in HNSCC.