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The cytogenetic alterations in renal oncocytoma (RO) are poorly understood. We analyzed 130 consecutive RO for karyotypic alterations. Clonal chromosome abnormalities were identified in 63 (49%) cases, which could be categorized into three classes of mutually exclusive cytogenetic categories. Class 1 (N = 20) RO had diploid karyotypes with characteristic 11q13 rearrangement in balanced translocations with 10 or more different chromosome partners in all cases. We identified recurrent translocation partners at 5q35, 6p21, 9p24, 11p13-14, and 11q23, and confirmed that CCND1 gene rearrangement at 11q13 utilizing fluorescence in situ hybridization (FISH). Class 2 RO (N = 25) exhibited hypodiploid karyotypes with loss of chromosome 1 and/or losses of Y in males and X in females in all cases. The class 3 tumors comprising of 18 cases showed diverse types of abnormalities with the involvement of two or more chromosomes exclusive of abnormalities seen in classes 1 and 2 tumors. Furthermore, karyotypically uninformative cases were subjected to FISH analysis to identify classes 1 and 2 abnormalities. In this group, we found similar frequencies of CCND1 rearrangement, loss of chromosome 1 or Y as with karyotypically abnormal cases. We validated our results against 91 tumors from the Mitelman database. Correlation of clinical data with all the three classes of ROs showed no clear evidence of overall patient survival. Our findings support the hypothesis that RO exhibit three principal cytogenetic categories, which may have different roles in initiation and/or progression. These cytogenetic markers provide a key tool in the diagnostic evaluation of RO.
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PURPOSE: Accurate discrimination of benign oncocytoma and malignant renal cell carcinoma is useful for planning appropriate treatment strategies for patients with renal masses. Classification of renal neoplasms solely based on histopathology can be challenging, especially the distinction between chromophobe renal cell carcinoma and oncocytoma. In this study we develop and validate an algorithm based on genomic alterations for the classification of common renal neoplasms. MATERIALS AND METHODS: Using TCGA renal cell carcinoma copy number profiles and the published literature, a classification algorithm was developed and scoring criteria were established for the presence of each genomic marker. As validation, 191 surgically resected formalin fixed paraffin embedded renal neoplasms were blindly submitted to targeted array comparative genomic hybridization and classified according to the algorithm. CCND1 rearrangement was assessed by fluorescence in situ hybridization. RESULTS: The optimal classification algorithm comprised 15 genomic markers, and involved loss of VHL, 3p21 and 8p, and chromosomes 1, 2, 6, 10 and 17, and gain of 5qter, 16p, 17q and 20q, and chromosomes 3, 7 and 12. On histological rereview (leading to the exclusion of 3 specimens) and using histology as the gold standard, 58 of 62 (93%) clear cell, 51 of 56 (91%) papillary and 33 of 34 (97%) chromophobe renal cell carcinomas were classified correctly. Of the 36 oncocytoma specimens 33 were classified as oncocytoma (17 by array comparative genomic hybridization and 10 by array comparative genomic hybridization plus fluorescence in situ hybridization) or benign (6). Overall 93% diagnostic sensitivity and 97% specificity were achieved. CONCLUSIONS: In a clinical diagnostic setting the implementation of genome based molecular classification could serve as an ancillary assay to assist in the histological classification of common renal neoplasms.
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Adenoma Oxifílico/clasificación , Adenoma Oxifílico/genética , Algoritmos , Carcinoma de Células Renales/clasificación , Carcinoma de Células Renales/genética , Genómica , Corteza Renal , Neoplasias Renales/clasificación , Neoplasias Renales/genética , Hibridación Genómica Comparativa , Humanos , Hibridación Fluorescente in SituRESUMEN
PCDH10 is epigenetically inactivated in multiple tumor types; however, studies in mature lymphoid malignancies are limited. Here, we have investigated the presence of promoter hypermethylation of the PCDH10 gene in a large cohort of well-characterized subsets of lymphomas. PCDH10 promoter hypermethylation was identified by methylation-specific PCR in 57 to 100% of both primary B- and T-cell lymphoma specimens and cell lines. These findings were further validated by Sequenom Mass-array analysis. Promoter hypermethylation was also identified in 28.6% cases of reactive follicular hyperplasia, more commonly occurring in states of immune deregulation and associated with rare presence of clonal karyotypic aberrations, suggesting that PCDH10 methylation occurs early in lymphomagenesis. PCDH10 expression was down regulated via promoter hypermethylation in T- and B-cell lymphoma cell lines. The transcriptional down-regulation resulting from PCDH10 methylation could be restored by pharmacologic inhibition of DNA methyltransferases in cell lines. Both T- and B-cell lymphoma cell lines harboring methylation-mediated inactivation of PCDH10 were resistant to doxorubicin treatment, suggesting that hypermethylation of this gene might contribute to chemotherapy response.
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Antibióticos Antineoplásicos/farmacología , Cadherinas/genética , Metilación de ADN , Doxorrubicina/farmacología , Linfoma no Hodgkin/genética , Mieloma Múltiple/genética , Regiones Promotoras Genéticas , Apoptosis/efectos de los fármacos , Carcinogénesis/genética , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Metilasas de Modificación del ADN/antagonistas & inhibidores , Regulación hacia Abajo/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Cariotipo , Linfoma no Hodgkin/patología , Mieloma Múltiple/patología , Protocadherinas , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Hairy cell leukaemia (HCL) is a rare type of B-cell non-Hodgkin lymphoma (B-NHL), which is not known to be associated with any characteristic recurrent karyotypic abnormality. A recent study that used massively parallel whole exome sequencing identified an activating V600E mutation in BRAF, which appeared specific for HCL. Here, we confirm the specificity of BRAF V600E for HCL among low and intermediate grade B-NHL and describe a real-time polymerase chain reaction method for detecting this mutation in cases with low tumour burden. The V600E mutation does not appear to be associated with microsatellite instability, unlike the case in colorectal cancer. Thus, in conjunction with prior data, our results suggest incorporation of BRAF V600E mutation analysis in the diagnostic workup of HCL cases. Additionally, targeting the Ras-Raf-Mek-Erk-Map kinase pathway should be investigated as a potential therapeutic strategy for patients with this disease.
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Leucemia de Células Pilosas/genética , Linfoma de Células B/genética , Linfoma no Hodgkin/genética , Recurrencia Local de Neoplasia/genética , Mutación Puntual/genética , Proteínas Proto-Oncogénicas B-raf/genética , Adulto , Anciano , Femenino , Humanos , Leucemia de Células Pilosas/complicaciones , Leucemia de Células Pilosas/patología , Linfoma de Células B/complicaciones , Linfoma de Células B/patología , Linfoma no Hodgkin/complicaciones , Linfoma no Hodgkin/patología , Masculino , Inestabilidad de Microsatélites , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Pronóstico , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Adulto JovenRESUMEN
BACKGROUND: The diagnosis of indeterminate biliary strictures is limited because of the low sensitivity of cytology. However, an accurate diagnosis of malignancy is critical in the management of patients with suspected biliary malignancy. Testing for chromosomal aneuploidy by fluorescence in situ hybridization (FISH) may increase the yield. OBJECTIVE: To evaluate the diagnostic accuracy of FISH in indeterminate biliary strictures and the additional value of including deletion of 9p21 (p16) in the diagnostic criteria of malignant biliary strictures. DESIGN: Retrospective review. SETTING: Academic medical center. PATIENTS: This study involved 76 consecutive patients who were seen for the evaluation of indeterminate strictures at our institution. These patients were screened, and 50 patients with either a final pathologic diagnosis or ≥ 12 months' conclusive follow-up were included in the analysis. MAIN OUTCOME MEASUREMENTS: Sensitivity, specificity, and area under the curve (AUC) analysis of cytology alone compared with the presence of FISH polysomy versus FISH polysomy and 9p21 deletion. RESULTS: The presence of increased copy numbers (polysomy) of chromosome 3, 7, or 17 by FISH increased the sensitivity of brush cytology from 21% to 58%, and when the presence of 9p21 deletion was included, the sensitivity increased to 89%. The specificity of FISH was 97% (vs 100% for cytology). The accuracy of cytology combined with FISH polysomy (AUC = 0.93) or p16 deletion was significantly greater than the accuracy of cytology alone (AUC 0.6; P < .001) or even cytology combined with FISH polysomy (AUC = 0.77; P ≤ .05). LIMITATIONS: Sample size. There is a relatively high incidence of malignant biliary strictures in the entire cohort but low incidence among primary sclerosing cholangitis patients, and the majority of cancers are cholangiocarcinomas (as opposed to pancreatic). CONCLUSION: FISH significantly improves the diagnostic accuracy of brush cytology in indeterminate biliary strictures. In our series, the addition of 9p21 deletion to FISH polysomy and cytology further improved sensitivity. This suggests that 9p21 deletion may be added to the diagnostic criteria in indeterminate strictures.
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Neoplasias de los Conductos Biliares/genética , Conductos Biliares Intrahepáticos/patología , Colangiocarcinoma/genética , Deleción Cromosómica , ADN de Neoplasias/genética , Genes p16 , Hibridación Fluorescente in Situ , Aneuploidia , Área Bajo la Curva , Neoplasias de los Conductos Biliares/complicaciones , Neoplasias de los Conductos Biliares/diagnóstico , Colangiocarcinoma/complicaciones , Colangiocarcinoma/diagnóstico , Colangitis Esclerosante/complicaciones , Colangitis Esclerosante/diagnóstico , Cromosomas Humanos Par 17 , Cromosomas Humanos Par 3 , Cromosomas Humanos Par 7 , Cromosomas Humanos Par 9 , Constricción Patológica/etiología , Constricción Patológica/patología , Citodiagnóstico , Femenino , Humanos , Masculino , Curva ROC , Estudios RetrospectivosRESUMEN
PCDH10 has been implicated as a tumor suppressor, since epigenetic alterations of this gene have been noted in multiple tumor types. However, to date, studies regarding its role in acute and chronic leukemias are lacking. Here, we have investigated the presence of promoter hypermethylation of two CpG islands of the PCDH10 gene by methylation-specific PCR in 215 cases of various subsets of myeloid- and lymphoid-lineage leukemias. We found that PCDH10 promoter hypermethylation was frequent in both B-cell (81.9%) and T-cell (80%) acute lymphoblastic leukemia (ALL), while it was present in low frequency in most subtypes of myeloid leukemias (25.9%) and rare in chronic myeloid leukemia (2.2%). PCDH10 expression was downregulated via promoter hypermethylation in primary ALL samples (N = 4) and leukemia cell lines (N = 11). The transcriptional repression caused by PCDH10 methylation could be restored by pharmacologic inhibition of DNA methyltransferases. ALL cell lines harboring methylation-mediated inactivation of PCDH10 were less sensitive to commonly used leukemia-specific drugs suggesting that PCDH10 methylation might serve as a biomarker of chemotherapy response. Our results demonstrate that PCDH10 is a target of epigenetic silencing in ALL, a phenomenon that may impact lymphoid-lineage leukemogenesis, serve as an indicator of drug resistance and may also have potential implications for targeted epigenetic therapy.
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Cadherinas/genética , Metilación de ADN , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Linfocitos B/metabolismo , Médula Ósea/metabolismo , Cadherinas/metabolismo , Línea Celular Tumoral , Islas de CpG , Regulación hacia Abajo/genética , Resistencia a Antineoplásicos/genética , Epigénesis Genética/genética , Genes Supresores de Tumor , Humanos , Reacción en Cadena de la Polimerasa/métodos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Regiones Promotoras Genéticas , Protocadherinas , Linfocitos T/metabolismo , Proteínas Supresoras de Tumor/genéticaRESUMEN
Non-random karyotypic abnormalities associated with non-Hodgkin lymphomas (NHLs) have been described in cases of reactive lymphoid hyperplasia (RLH). However, the frequency and types of cytogenetic aberrations detected and their clinical relevance are unknown. To address these questions, we undertook a retrospective analysis of a large series of RLH diagnosed at our institute over 8 years. Cytogenetic abnormalities were identified in 20 of 116 (17%) cases with informative karyotypes, comprising 14 (70%) structural and 11 (55%) numerical changes. Clonal (n = 14, 70%) and non-clonal (n = 6, 30%) abnormalities were observed. Aberrations of chromosome 14 were the most frequent (n = 8, 42%, 7 represented IgH translocations), followed by chromosome 3 (n = 4, 3 represented BCL6 translocations), and chromosome 12 (n = 4). Abnormal karyotypes were most often associated with florid follicular hyperplasia. Isolated lymphoid organ (lymph node, tonsil or spleen) enlargement (12/20, 60%) was more common, no specific etiology was identified in 10/20 (50%) cases and only 1 of 18 patients with clinical follow-up (range 2-107 months, median 60 months) developed lymphoma. In our experience, cytogenetic abnormalities involving loci associated with B-cell NHL are not infrequently detected in RLH. Their occurrence portends low risk for lymphomagenesis, however longer follow-up is prudent to further evaluate the natural history of such cases.
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Aberraciones Cromosómicas , Centro Germinal/metabolismo , Linfoma/genética , Seudolinfoma/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Reordenamiento Génico , Centro Germinal/patología , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Hibridación in Situ , Hibridación Fluorescente in Situ , Lactante , Cariotipificación , Linfoma/patología , Masculino , Persona de Mediana Edad , Seudolinfoma/patología , Receptores de Antígenos de Linfocitos T gamma-delta/genética , Estudios Retrospectivos , Adulto JovenRESUMEN
Lesions of ERBB2, PTEN, and PIK3CA activate the phosphatidylinositol 3-kinase (PI3K) pathway during cancer development by increasing levels of phosphatidylinositol-3,4,5-triphosphate (PIP(3)). 3-Phosphoinositide-dependent kinase 1 (PDK1) is the first node of the PI3K signal output and is required for activation of AKT. PIP(3) recruits PDK1 and AKT to the cell membrane through interactions with their pleckstrin homology domains, allowing PDK1 to activate AKT by phosphorylating it at residue threonine-308. We show that total PDK1 protein and mRNA were overexpressed in a majority of human breast cancers and that 21% of tumors had five or more copies of the gene encoding PDK1, PDPK1. We found that increased PDPK1 copy number was associated with upstream pathway lesions (ERBB2 amplification, PTEN loss, or PIK3CA mutation), as well as patient survival. Examination of an independent set of breast cancers and tumor cell lines derived from multiple forms of human cancers also found increased PDK1 protein levels associated with such upstream pathway lesions. In human mammary cells, PDK1 enhanced the ability of upstream lesions to signal to AKT, stimulate cell growth and migration, and rendered cells more resistant to PDK1 and PI3K inhibition. After orthotopic transplantation, PDK1 overexpression was not oncogenic but dramatically enhanced the ability of ERBB2 to form tumors. Our studies argue that PDK1 overexpression and increased PDPK1 copy number are common occurrences in cancer that potentiate the oncogenic effect of upstream lesions on the PI3K pathway. Therefore, we conclude that alteration of PDK1 is a critical component of oncogenic PI3K signaling in breast cancer.
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Neoplasias de la Mama/enzimología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Quinasas Dependientes de 3-Fosfoinosítido , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Procesos de Crecimiento Celular/fisiología , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Transformación Celular Neoplásica/patología , Femenino , Dosificación de Gen , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones SCID , Proteína Oncogénica v-akt/metabolismo , Proteínas Serina-Treonina Quinasas/biosíntesis , Proteínas Serina-Treonina Quinasas/genética , Receptor ErbB-2/metabolismo , Transducción de SeñalRESUMEN
Diffuse large B-cell lymphoma (DLBCL), the most common form of lymphoma in adulthood, comprises multiple biologically and clinically distinct subtypes including germinal centre B-cell-like (GCB) and activated B-cell-like (ABC) DLBCL. Gene expression profile studies have shown that its most aggressive subtype, ABC-DLBCL, is associated with constitutive activation of the NF-kappaB transcription complex. However, except for a small fraction of cases, it remains unclear whether NF-kappaB activation in these tumours represents an intrinsic program of the tumour cell of origin or a pathogenetic event. Here we show that >50% of ABC-DLBCL and a smaller fraction of GCB-DLBCL carry somatic mutations in multiple genes, including negative (TNFAIP3, also called A20) and positive (CARD11, TRAF2, TRAF5, MAP3K7 (TAK1) and TNFRSF11A (RANK)) regulators of NF-kappaB. Of these, the A20 gene, which encodes a ubiquitin-modifying enzyme involved in termination of NF-kappaB responses, is most commonly affected, with approximately 30% of patients displaying biallelic inactivation by mutations and/or deletions. When reintroduced in cell lines carrying biallelic inactivation of the gene, A20 induced apoptosis and cell growth arrest, indicating a tumour suppressor role. Less frequently, missense mutations of TRAF2 and CARD11 produce molecules with significantly enhanced ability to activate NF-kappaB. Thus, our results demonstrate that NF-kappaB activation in DLBCL is caused by genetic lesions affecting multiple genes, the loss or activation of which may promote lymphomagenesis by leading to abnormally prolonged NF-kappaB responses.
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Regulación Neoplásica de la Expresión Génica , Genes/genética , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/fisiopatología , Mutación/genética , FN-kappa B/metabolismo , Apoptosis , Línea Celular Tumoral , Proteínas de Unión al ADN , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , FN-kappa B/antagonistas & inhibidores , FN-kappa B/genética , Proteínas Nucleares/genética , Proteína 3 Inducida por el Factor de Necrosis Tumoral alfaRESUMEN
Primary effusion lymphoma (PEL) is a rare type of B-cell non-Hodgkin lymphoma (NHL), which predominantly occurs in HIV-infected individuals, and is pathogenetically linked with Kaposi sarcoma (KS)-associated herpes virus/human herpes virus-8 (KSHV/HHV-8) infection with or without evidence of Epstein-Barr virus (EBV) co-infection. Although uncommon, PELs have been reported in immunocompetent patients and recipients of solid organ allografts. Rare cases of KSHV(-) EBV(+) post-transplant effusion lymphomas resembling PEL have also been described, as have KSHV(-) EBV(-) effusion lymphomas, the latter including those arising in individuals with chronic liver disease. We report a unique KSHV(-) EBV(-) post-transplant effusion lymphoma associated with serum paraproteins, occurring in an HIV(-) individual, which had cytologic features and phenotype similar to PEL, and displayed a complex karyotype including isochromosome 12p and translocation t(8;22), resulting in rearrangement of c-MYC.
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Linfoma de Efusión Primaria/patología , Infecciones por Virus de Epstein-Barr/genética , Infecciones por Virus de Epstein-Barr/patología , Herpesvirus Humano 4/aislamiento & purificación , Herpesvirus Humano 8/aislamiento & purificación , Humanos , Inmunofenotipificación , Trasplante de Hígado , Linfoma de Efusión Primaria/genética , Linfoma de Efusión Primaria/virología , Masculino , Persona de Mediana Edad , Células Plasmáticas/patología , Sarcoma de Kaposi/genética , Sarcoma de Kaposi/patología , Sarcoma de Kaposi/virologíaRESUMEN
Unique and shared cytogenetic abnormalities have been documented for marginal zone lymphomas (MZLs) arising at different sites. Recently, homozygous deletions of the chromosomal band 6q23, involving the tumor necrosis factor alpha-induced protein 3 (TNFAIP3, A20) gene, a negative regulator of NF-kappaB, were described in ocular adnexal MZL, suggesting a role for A20 as a tumor suppressor in this disease. Here, we investigated inactivation of A20 by DNA mutations or deletions in a panel of extranodal MZL (EMZL), nodal MZL (NMZL), and splenic MZL (SMZL). Inactivating mutations encoding truncated A20 proteins were identified in 6 (19%) of 32 MZLs, including 2 (18%) of 11 EMZLs, 3 (33%) of 9 NMZLs, and 1 (8%) of 12 SMZLs. Two additional unmutated nonsplenic MZLs also showed monoallelic or biallelic A20 deletions by fluorescent in situ hybridization (FISH) and/or SNP-arrays. Thus, A20 inactivation by either somatic mutation and/or deletion represents a common genetic aberration across all MZL subtypes, which may contribute to lymphomagenesis by inducing constitutive NF-kappaB activation.
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Eliminación de Gen , Péptidos y Proteínas de Señalización Intracelular/genética , Linfoma de Células B de la Zona Marginal/genética , Mutación Missense , Proteínas Nucleares/genética , Estudios de Casos y Controles , Transformación Celular Neoplásica/genética , Análisis Mutacional de ADN , Proteínas de Unión al ADN , Perfilación de la Expresión Génica , Humanos , Mutación Missense/fisiología , FN-kappa B/antagonistas & inhibidores , Análisis de Secuencia por Matrices de Oligonucleótidos , Polimorfismo de Nucleótido Simple , Proteína 3 Inducida por el Factor de Necrosis Tumoral alfaRESUMEN
Mutations in the phosphatase and tensin homologue (PTEN)/phosphatidylinositol-3 kinase-alpha (PI3K) signaling pathway are frequently found in human cancer. In addition, Pten(+/-) mice develop tumors in multiple organs because of the activation of the PI3K signaling cascade. Because activation of PI3K signaling leads to feedback inhibition of insulin receptor substrate-2 (IRS2) expression, an upstream activator of PI3K, we therefore anticipated that IRS2 expression would be low in tumors that lack PTEN. Surprisingly, however, an elevation of IRS2 was often detected in tumor samples in which PTEN levels were compromised. To determine the potential contribution of Irs2 to tumor progression, Pten(+/-) mice were crossed with Irs2(+/-) mice. Deletion of Irs2 did not affect the initiation of neoplasia found in Pten(+/-) mice but suppressed cancer cell growth, proliferation, and invasion through the basement membrane. Deletion of Irs2 also attenuated the expression of Myc in prostatic intraepithelial neoplasia in Pten(+/-) mice. In addition, the expression levels of IRS2 and MYC were highly correlated in human prostate cancer, and IRS2 could stimulate MYC expression in cultured cells. Our findings provide evidence that the PI3K-activating adaptor Irs2 contributes to tumor progression in Pten(+/-) mice by stimulating both Myc and DNA synthesis.
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Proteínas Sustrato del Receptor de Insulina/genética , Proteínas Sustrato del Receptor de Insulina/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Fosfohidrolasa PTEN/genética , Fosfohidrolasa PTEN/metabolismo , Animales , Western Blotting , Línea Celular Tumoral , Progresión de la Enfermedad , Neoplasias Endometriales/genética , Neoplasias Endometriales/metabolismo , Neoplasias Endometriales/patología , Femenino , Humanos , Inmunohistoquímica , Hibridación in Situ , Masculino , Ratones , Ratones Mutantes , Neoplasias/patología , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Proteínas Proto-Oncogénicas c-myc/metabolismo , TransfecciónRESUMEN
Cytogenetic abnormalities of chromosome 12p involving the TEL/ETV6 gene are observed in a variety of hematopoietic neoplasms including acute leukemias, myelodysplastic syndromes, and myeloproliferative disorders. Karyotypic aberrations, including rearrangements, deletions, and amplifications of chromosome 12p, have been documented in B-cell non-Hodgkin lymphoma; however, rearrangements targeting TEL have rarely been reported. Here we describe a diffuse large B-cell lymphoma that had a complex karyotype including t(9;12)(q22;p13), which was confirmed by fluorescence in situ hybridization to represent rearrangement of TEL. Additional cytogenetic abnormalities included t(3;14)(q27;q32) involving the variant, alternative breakpoint region of the BCL6 gene and del(6)(q13q23), resulting in the loss of 1 allele of BLIMP1. This case reiterates the importance of correlating morphologic and phenotypic findings with the results of cytogenetic analysis to avoid errors in diagnosing hematologic neoplasms and highlights the rare association of B-cell non-Hodgkin lymphoma with aberrations of TEL.
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Linfoma de Células B Grandes Difuso/genética , Neoplasias Primarias Secundarias/genética , Proteínas Proto-Oncogénicas c-ets/genética , Proteínas Represoras/genética , Adulto , Aberraciones Cromosómicas , Femenino , Citometría de Flujo , Reordenamiento Génico de Linfocito B , Enfermedad de Hodgkin/complicaciones , Enfermedad de Hodgkin/terapia , Humanos , Inmunohistoquímica , Hibridación Fluorescente in Situ , Linfoma de Células B Grandes Difuso/complicaciones , Linfoma de Células B Grandes Difuso/patología , Neoplasias Primarias Secundarias/patología , Neoplasias Primarias Secundarias/terapia , Translocación Genética , Proteína ETS de Variante de Translocación 6RESUMEN
Dual IgH/BCL2 and BCL6 translocations are rarely observed in B-cell non-Hodgkin lymphomas (B-NHLs). We investigated the morphologic, phenotypic, and cytogenetic spectrum of B-NHL with such dual translocations. Dual IgH/BCL2 and BCL6 translocations were detected in follicular lymphomas (FLs) and diffuse large B-cell lymphomas (DLBCLs), representing 6.1% of 132 B-NHLs in our series, including 6 (11%) of 56 FLs (grades 1, 2, and 3a) and 2 (3%) of 76 DLBCLs; 33% of FLs with dual translocations had variant morphologic features. All dual-translocation FLs were CD10+/BCL6+/BCL2+/MUM1-, and the DLBCLs demonstrated "activated" germinal center (CD10+/BCL6+/MUM1+) and non-germinal center (CD10-/BCL6+/MUM1+) phenotypes. BCL6 translocations in all cases involved nonimmunoglobulin genes/loci. Mean chromosome abnormalities in dual-translocation FLs and DLBCLs did not differ from IgH/BCL2 FLs and DLBCLs. Detection of dual translocations predominantly in low-grade FLs suggests that BCL6 abnormalities are acquired early in the histologic evolution of a subset of IgH/BCL2-associated FLs.
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Cromosomas Humanos Par 14 , Cromosomas Humanos Par 18 , Genes bcl-2 , Cadenas Pesadas de Inmunoglobulina/genética , Linfoma de Células B/genética , Proteínas Proto-Oncogénicas c-bcl-6/genética , Translocación Genética , Adulto , Anciano , Anciano de 80 o más Años , Cromosomas Humanos Par 3 , Femenino , Genes de Inmunoglobulinas , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: Copy number gains and amplifications are characteristic feature of cervical cancer (CC) genomes for which the underlying mechanisms are unclear. These changes may possess oncogenic properties by deregulating tumor-related genes. Gain of short arm of chromosome 5 (5p) is the most frequent karyotypic change in CC. METHODS: To examine the role of 5p gain, we performed a combination of single nucleotide polymorphism (SNP) array, fluorescence in situ hybridization (FISH), and gene expression analyses on invasive cancer and in various stages of CC progression. RESULTS: The SNP and FISH analyses revealed copy number increase (CNI) of 5p in 63% of invasive CC, which arises at later stages of precancerous lesions in CC development. We integrated chromosome 5 genomic copy number and gene expression data to identify key target over expressed genes as a consequence of 5p gain. One of the candidates identified was Drosha (RNASEN), a gene that is required in the first step of microRNA (miRNA) processing in the nucleus. Other 5p genes identified as targets of CNI play a role in DNA repair and cell cycle regulation (BASP1, TARS, PAIP1, BRD9, RAD1, SKP2, and POLS), signal transduction (OSMR), and mitochondrial oxidative phosphorylation (NNT, SDHA, and NDUFS6), suggesting that disruption of pathways involving these genes may contribute to CC progression. CONCLUSION: Taken together, we demonstrate the power of integrating genomics data with expression data in deciphering tumor-related targets of CNI. Identification of 5p gene targets in CC denotes an important step towards biomarker development and forms a framework for testing as molecular therapeutic targets.
Asunto(s)
Cromosomas Humanos Par 5 , Amplificación de Genes , Regulación Neoplásica de la Expresión Génica , Genómica , Lesiones Precancerosas/genética , Ribonucleasa III/genética , Displasia del Cuello del Útero/genética , Neoplasias del Cuello Uterino/genética , Línea Celular Tumoral , Colombia , Progresión de la Enfermedad , Femenino , Alemania , Humanos , Hibridación Fluorescente in Situ , Invasividad Neoplásica , New York , Análisis de Secuencia por Matrices de Oligonucleótidos , Polimorfismo de Nucleótido Simple , Lesiones Precancerosas/patología , Reproducibilidad de los Resultados , Transcripción Genética , Neoplasias del Cuello Uterino/patología , Displasia del Cuello del Útero/patologíaRESUMEN
Recurrent karyotypic abnormalities are a characteristic feature of cervical cancer (CC) cells, which may result in deregulated expression of important genes that contribute to tumor initiation and progression. To examine the role of gain of the long arm of chromosome 20 (20q), one of the common chromosomal gains in CC, we evaluated CC at various stages of progression using single nucleotide polymorphism (SNP) array, gene expression profiling, and fluorescence in situ hybridization (FISH) analyses. This analysis revealed copy number increase (CNI) of 20q in >50% of invasive CC and identified two focal amplicons at 20q11.2 and 20q13.13 in a subset of tumors. We further demonstrate that the acquisition of 20q gain occurs at an early stage in CC development and the high-grade squamous intraepithelial lesions (HSIL) that exhibit 20q CNI are associated (P = 0.05) with persistence or progression to invasive cancer. We identified a total of 26 overexpressed genes as consequence of 20q gain (N = 14), as targets of amplicon 1 (N = 9; two genes also commonly expressed with 20q gain) and amplicon 2 (N = 6; one gene also commonly expressed with 20q gain). These include a number of functionally important genes in cell cycle regulation (E2F1, TPX2, KIF3B, PIGT, and B4GALT5), nuclear function (CSEL1), viral replication (PSMA7 and LAMA5), methylation and chromatin remodeling (ASXL1, AHCY, and C20orf20), and transcription regulation (TCEA2). Our findings implicate a role for these genes in CC tumorigenesis, represent an important step toward the development of clinically significant biomarkers, and form a framework for testing as molecular therapeutic targets.
Asunto(s)
Cromosomas Humanos Par 20 , Amplificación de Genes , Dosificación de Gen , Neoplasias del Cuello Uterino/genética , Progresión de la Enfermedad , Femenino , Perfilación de la Expresión Génica , Genoma , Genómica , Humanos , Hibridación Fluorescente in Situ , Polimorfismo de Nucleótido Simple , Neoplasias del Cuello Uterino/patologíaRESUMEN
Women with germ-line mutations of the BRCA1 tumor suppressor gene are highly susceptible to breast and ovarian cancer. The protein product of BRCA1 is involved in a broad spectrum of biological processes and interacts with many diverse proteins. One of these, BARD1, associates with BRCA1 to form a heterodimeric complex that is enzymatically active as an ubiquitin E3 ligase. Although the BRCA1/BARD1 heterodimer has been implicated in several aspects of BRCA1 function, its role in tumor suppression has not been evaluated. To address this question, we generated mouse strains carrying conditional alleles of either Bard1 or Brca1 and used Cre recombination to inactivate these genes in mammary epithelial cells. Significantly, the conditional Bard1- and Brca1-mutant mice developed breast carcinomas that are indistinguishable from each other (and from those of double conditional Bard1/Brca1-mutant animals) with respect to their frequency, latency, histopathology, and cytogenetic features. Reminiscent of the basal-like breast carcinomas seen in human BRCA1 mutation carriers, these tumors are "triple negative" for estrogen and progesterone receptor expression and HER2/neu amplification. They also express basal cytokeratins CK5 and CK14, have an elevated frequency of p53 lesions, and display high levels of chromosomal instability. The remarkable similarities between the mammary carcinomas of Bard1-, Brca1-, and Bard1/Brca1-mutant mice indicate that the tumor suppressor activities of both genes are mediated through the BRCA1/BARD1 heterodimer.
Asunto(s)
Proteína BRCA1/genética , Neoplasias Mamarias Animales/patología , Mutación/genética , Proteínas Supresoras de Tumor/genética , Ubiquitina-Proteína Ligasas/genética , Animales , Proteína BRCA1/metabolismo , Inestabilidad Cromosómica , Dimerización , Femenino , Marcación de Gen , Inmunohistoquímica , Cariotipificación , Ratones , Especificidad de Órganos , Fenotipo , Análisis de Supervivencia , Proteína p53 Supresora de Tumor/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
The BRCA1 tumor suppressor exists as a heterodimeric complex with BARD1, and this complex is thought to mediate many of the functions ascribed to BRCA1, including its role in tumor suppression. The two proteins share a common structural organization that features an N-terminal RING domain and two C-terminal BRCT motifs, whereas BARD1 alone also contains three tandem ankyrin repeats. In normal cells, the BRCA1/BARD1 heterodimer is believed to enhance chromosome stability by promoting homology-directed repair (HDR) of double strand DNA breaks. Here we have investigated the structural requirements for BARD1 in this process by complementation of Bard1-null mouse mammary carcinoma cells. Our results demonstrate that the ankyrin and BRCT motifs of BARD1 are each essential for both chromosome stability and HDR. Tandem BRCT motifs, including those found at the C terminus of BARD1, are known to form a phosphoprotein recognition module. Nonetheless, the HDR function of BARD1 was not perturbed by synthetic mutations predicted to ablate the phospho-recognition activity of its BRCT sequences, suggesting that some functions of the BRCT domains are not dependent on their ability to bind phosphorylated ligands. Also, cancer-associated missense mutations in the BRCT domains of BARD1 (e.g. C557S, Q564H, V695L, and S761N) have been observed in patients with breast, ovarian, and endometrial tumors. However, none of these was found to affect the HDR activity of BARD1, suggesting that any increased cancer risk conferred by these mutations is not because of defects in this repair mechanism.
Asunto(s)
Proteína BRCA1/metabolismo , Inestabilidad Cromosómica , Roturas del ADN de Doble Cadena , Neoplasias Mamarias Animales/metabolismo , Complejos Multiproteicos/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Sustitución de Aminoácidos , Animales , Ancirinas/genética , Proteína BRCA1/genética , Línea Celular Tumoral , Inestabilidad Cromosómica/genética , Reparación del ADN/genética , Femenino , Prueba de Complementación Genética , Humanos , Masculino , Neoplasias Mamarias Animales/genética , Ratones , Complejos Multiproteicos/genética , Mutación Missense , Dominios RING Finger/genética , Factores de Riesgo , Relación Estructura-Actividad , Proteínas Supresoras de Tumor/genética , Ubiquitina-Proteína Ligasas/genéticaRESUMEN
Cervical cancer (CC) cells exhibit complex karyotypic alterations, which is consistent with deregulation of numerous critical genes in its formation and progression. To characterize this karyotypic complexity at the molecular level, we used cDNA array comparative genomic hybridization (aCGH) to analyze 29 CC cases and identified a number of over represented and deleted genes. The aCGH analysis revealed at least 17 recurrent amplicons and six common regions of deletions. These regions contain several known tumor-associated genes, such as those involved in transcription, apoptosis, cytoskeletal remodeling, ion-transport, drug metabolism, and immune response. Using the fluorescence in situ hybridization (FISH) approach we demonstrated the presence of high-level amplifications at the 8q24.3, 11q22.2, and 20q13 regions in CC cell lines. To identify amplification-associated genes that correspond to focal amplicons, we examined one or more genes in each of the 17 amplicons by Affymetrix U133A expression arrays and semiquantitative reverse-transcription PCR (RT-PCR) in 31 CC tumors. This analysis exhibited frequent and robust upregulated expression in CC relative to normal cervix for genes EPHB2 (1p36), CDCA8 (1p34.3), AIM2 (1q22-23), RFC4, MUC4, and HRASLS (3q27-29), SKP2 (5p12-13), CENTD3 (5q31.3), PTK2, RECQL4 (8q24), MMP1 and MMP13 (11q22.2), AKT1 (14q32.3), ABCC3 (17q21-22), SMARCA4 (19p13.3) LIG1 (19q13.3), UBE2C (20q13.1), SMC1L1 (Xp11), KIF4A (Xq12), TMSNB (Xq22), and CSAG2 (Xq28). Thus, the gene dosage and expression profiles generated here have enabled the identification of focal amplicons characteristic for the CC genome and facilitated the validation of relevant genes in these amplicons. These data, thus, form an important step toward the identification of biologically relevant genes in CC pathogenesis. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045-2257/suppmat.
Asunto(s)
Amplificación de Genes , Dosificación de Gen , Expresión Génica , Análisis de Secuencia por Matrices de Oligonucleótidos , Neoplasias del Cuello Uterino/genética , Línea Celular Tumoral , Femenino , HumanosRESUMEN
Cancer cells exhibit nonrandom and complex chromosome abnormalities. The role of genomic changes in cancer is well established. However, the identification of complex and cryptic chromosomal changes is beyond the resolution of conventional banding methods. The fluorescence microscopy afforded by imaging technologies, developed recently, facilitates a precise identification of these chromosome alterations in cancer. The three most commonly utilized molecular cytogenetics methods comparative genomic hybridization, spectral karyotype, and fluorescence in situ hybridization, that have already become benchmark tools in cancer cytogenetics, are described in this chapter. Comparative genomic hybridization is a powerful tool for screening copy-number changes in tumor genomes without the need for preparation of metaphases from tumor cells. Multicolor spectral karyotype permits visualization of all chromosomes in one experiment permitting identification of precise chromosomal changes on metaphases derived from tumor cells. The uses of fluorescence in situ hybridization are diverse, including mapping of alteration in single copy genes, chromosomal regions, or entire chromosomes. The opportunities to detect genetic alterations in cancer cells continue to evolve with the use of these methodologies both in diagnosis and research.