Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Pharmaceutics ; 15(2)2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36839973

RESUMO

Abiraterone acetate (AA) is the first-in-class of drugs belonging to the second-generation of agents inhibiting androgen neosynthesis in advanced prostate cancer. A cumulative experience attests that germinal gene polymorphisms may play a role in the prediction of anticancer agent pharmacodynamics variability. In the present prospective, multicentric study, gene polymorphisms of CYP17A1 (AA direct target) and the androgen transporter genes SLCO2B1 and SLCO1B3 (potential modulators of AA activity) were confronted with AA pharmacodynamics (treatment response and toxicity) in a group of 137 advanced prostate cancer patients treated in the first line by AA. The median follow-up was 56.3 months (95% CI [52.5-61]). From multivariate analysis, rs2486758 C/C (CYP17A1) and PSA (≥10 ng/mL) were associated with a shorter 3-year biological PFS (HR = 4.05, IC95% [1.46-11.22]; p = 0.007 and HR = 2.08, IC95% [1.31-3.30]; p = 0.002, respectively). From a multivariate analysis, the rs743572 (CYP17A1) and performance status were independently associated with significant toxicity (OR = 3.78 (IC95% [1.42-9.75]; p = 0.006 and OR = 4.54; IC95% [1.46-13.61]; p = 0.007, respectively). Host genome characteristics may help to predict AA treatment efficacy and identify patients at risk for toxicity.

3.
Pharmaceuticals (Basel) ; 13(11)2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33238394

RESUMO

The prospective multicenter COMET trial followed a cohort of 306 consecutive metastatic breast cancer patients receiving bevacizumab and paclitaxel as first-line chemotherapy. This study was intended to identify and validate reliable biomarkers to better predict bevacizumab treatment outcomes and allow for a more personalized use of this antiangiogenic agent. To that end, we aimed to establish risk scores for survival prognosis dichotomization based on classic clinico-pathological criteria combined or not with single nucleotide polymorphisms (SNPs). The genomic DNA of 306 patients was extracted and a panel of 13 SNPs, covering seven genes previously documented to be potentially involved in drug response, were analyzed by means of high-throughput genotyping. In receiver operating characteristic (ROC) analyses, the hazard model based on a triple-negative cancer phenotype variable, combined with specific SNPs in VEGFA (rs833061), VEGFR1 (rs9582036) and VEGFR2 (rs1870377), had the highest predictive value. The overall survival hazard ratio of patients assigned to the poor prognosis group based on this model was 3.21 (95% CI (2.33-4.42); p < 0.001). We propose that combining this pharmacogenetic approach with classical clinico-pathological characteristics could markedly improve clinical decision-making for breast cancer patients receiving bevacizumab-based therapy.

4.
Sci Rep ; 10(1): 9857, 2020 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-32528006

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

5.
Sci Rep ; 10(1): 3565, 2020 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-32107407

RESUMO

Hyperprogressive disease (HPD), an unexpected acceleration of tumor growth kinetics, is described in cancer patients treated with anti-PD-1/anti-PD-L1 agents. Here, our aim was to take into consideration the host and explore whether single nucleotide polymorphisms (SNPs) in key genes involved in immune response might predispose to HPD. DNA was extracted from blood-samples from 98 patients treated under CPI monotherapy. Four candidate genes (PD-1, PD-L1, IDO1 and VEGFR2) and 15 potential SNPs were selected. The TGKR (ratio of the slope of tumor growth before treatment and the slope of tumor growth on treatment) was calculated. Hyperprogression was defined as a TGKR≥2. TGKR calculation was feasible for 80 patients (82%). HPD was observed for 11 patients (14%) and was associated with shorter overall survival (P = 0.003). In univariate analysis, HPD was significantly associated with age ≥70 y (P = 0.025), immune-related toxicity (P = 0.016), VEGFR2 rs1870377 A/T or A/A (P = 0.005), PD-L1 rs2282055 G/T or G/G (P = 0.024) and PD-L1 rs2227981 G/A or A/A (P = 0.024). Multivariate analysis confirmed the correlation between HPD and age ≥70 y (P = 0.006), VEGFR2 rs1870377 A/T or A/A (P = 0.007) and PD-L1 rs2282055 G/T or G/G (P = 0.018). Immunogenetics could become integral predictive factors for CPI-based immunotherapy.


Assuntos
Inibidores de Checkpoint Imunológico/administração & dosagem , Neoplasias/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/administração & dosagem , Antígeno B7-H1/genética , Antígeno B7-H1/imunologia , Proliferação de Células , Progressão da Doença , Feminino , Humanos , Imunogenética , Masculino , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Neoplasias/mortalidade , Polimorfismo de Nucleotídeo Único , Receptor de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/imunologia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/imunologia
6.
Invest New Drugs ; 38(1): 160-171, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31402427

RESUMO

Background Checkpoint inhibitors bring marked benefits but only in a minority of patients and may also be associated with severe adverse events. Treatment outcome still cannot be faithfully predicted. The following study hypothesized that host genetics could be applied as predictive biomarkers for checkpoint inhibitor response and immune-related adverse events. We conducted a study based on germinal polymorphisms from genes coding for proteins involved in immune regulation. Methods Germinal DNA was obtained from advanced cancer patients treated with anti-PD-1/PD-L1 checkpoint inhibitors. DNA was genotyped using a custom panel of 166 single nucleotide polymorphisms covering 86 preselected immunogenetic-related genes. Computational analysis using a GTEX portal was made to determine potential expression Quantitative Trait Loci in tissues. Results Ninety-four consecutive patients were included. Objective response rate (complete or partial response) was significantly correlated to tumor microenvironment-related SNPs concerning CCL2, NOS3, IL1RN, IL12B, CXCR3 and IL6R genes. Toxicity were linked to target-related gene SNPs including UNG, IFNW1, CTLA4, PD-L1 and IFNL4 genes. The Area Under the ROC curve (AUC) was 0.81 (95% CI: 0.72-0.9) for response and 0.89 (95% CI: 0.76-1.00) for toxicity. In silico functionality exploring pointed rs4845618 (IL6R), rs10964859 (IFNW1) and rs3087243 (CTLA4) as potentially impacting gene expression. Conclusion These results strongly support a role for distinct immunogenetic-related gene SNPs able to predict efficacy and safety of anti-PD1/PD-L1 therapies. The results highlight the existence of patient-specific, germinal biomarkers able predict response to checkpoint inhibitor efficacy and, possibly, to predict treatment-related adverse events.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Antígeno B7-H1/antagonistas & inibidores , Biomarcadores Tumorais/genética , Mutação em Linhagem Germinativa , Imunogenética , Neoplasias/mortalidade , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Imunoterapia , Masculino , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Testes Farmacogenômicos , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
8.
Lung Cancer ; 118: 62-68, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29572005

RESUMO

INTRODUCTION: The systematic assessment of anti-programmed cell death ligand 1 (PD-L1) expression by immunohistochemistry (IHC) in lung adenocarcinomas is becoming standard practice. However, the assessment of PD-L1 expression on small tissue specimens needs to be evaluated and the association with other features more thoroughly analyzed. METHODS: This retrospective single center study evaluated the immunohistochemical expression of the SP263 anti-PD-L1 antibody on tissue microarrays (TMA) of 152 surgically resected lung adenocarcinomas, using a 25% positivity threshold. The positive cases and 50 randomly chosen negative cases in tissue microarray (TMA) were reassessed on whole tissue sections. The results were correlated to clinical, histopathological and to molecular data obtained through the screening of 214 mutations in 26 genes (LungCarta panel, Agena Biosciences). RESULTS: Among 152 primary lung adenocarcinomas, 19 cases (13%) showed PD-L1 expression. The agreement between TMA and whole tissue sections was 89%, specificity was 97%. PD-L1 expression was correlated to RAS mutations (p = .04), RAS/TP53 co-mutations (p = .01) and to the solid or acinar subtype (p = .048). CONCLUSIONS: With the SP263 PD-L1 antibody, small samples appear as a reliable means to evaluate the PD-L1 status in lung adenocarcinoma. The association between PD-L1 expression and RAS/TP53 mutations may have clinical relevance to predict the efficacy of PD-1/PD-L1 immune checkpoints inhibitors.


Assuntos
Adenocarcinoma de Pulmão/metabolismo , Antígeno B7-H1/metabolismo , Biomarcadores Tumorais/metabolismo , Neoplasias Pulmonares/metabolismo , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Genes ras , Humanos , Imuno-Histoquímica , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Mutação/genética , Estudos Retrospectivos , Análise de Sobrevida , Análise Serial de Tecidos , Proteína Supressora de Tumor p53/genética
9.
Head Neck ; 39(1): 151-159, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27507562

RESUMO

BACKGROUND: The purpose of this study was to investigate the effects of combining the phosphotidylinositol-3-kinase (PI3K) inhibitor buparlisib (BKM)120 with the anti-epidermal growth factor receptor (EGFR) agent cetuximab and radiotherapy (RT) on an orthotopic model of head and neck squamous cell carcinoma (HNSCC). METHODS: We evaluated the antitumor efficacy of BKM120, cetuximab, and RT, administered alone or in combination, using the human PIK3CA-mutated HNSCC cell line, CAL33, injected into the floor of the mouth of nude mice. RESULTS: Compared with control, the BKM120-cetuximab and the BKM120-cetuximab-RT combinations led to the highest tumor inhibition (p < .001). The highest inhibitory effect of treatments on cell proliferation, mitogen-activated protein kinase (MAPK) and PI3K/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathways were found with the BKM120-cetuximab association. The association of BKM120 and cetuximab with RT inhibited RT-induced activation of the MAPK pathway. CONCLUSION: These results can serve as a preclinical rationale for innovative treatments combining PI3K inhibition with anti-EGFR therapies and irradiation in patients with HNSCC. © 2016 Wiley Periodicals, Inc. Head Neck 39: 151-159, 2017.


Assuntos
Aminopiridinas/uso terapêutico , Antineoplásicos Imunológicos/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Cetuximab/uso terapêutico , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/radioterapia , Morfolinas/uso terapêutico , Inibidores de Fosfoinositídeo-3 Quinase , Animais , Carcinoma de Células Escamosas/patologia , Terapia Combinada , Modelos Animais de Doenças , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Camundongos , Camundongos Nus , Carcinoma de Células Escamosas de Cabeça e Pescoço , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Laryngoscope ; 126(4): E156-63, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26597440

RESUMO

OBJECTIVES/HYPOTHESIS: Recent preclinical and clinical studies on head and neck squamous cell carcinoma (HNSCC) revealed synergistic effects when combining anti-EGFR agents with conventional chemotherapeutic drugs. Activation of the PI3-kinase/AKT/mTOR signaling pathway has been identified as an important mechanism implicated in tumor progression and resistance to EGFR inhibitors. The aim of this study was to investigate the effects of combining the mTOR inhibitor temsirolimus (Tem) with the anti-EGFR agent cetuximab (Cet) and conventional chemotherapeutic drugs (cisplatin and fluorouracil (C/F)) on an orthotopic model of HNSCC. STUDY DESIGN: Preclinical in vivo study. METHODS: We evaluated the anti-tumor efficacy (measured tumor volume) of Tem, Cet, and C/F, administered alone or in combination. Investigations were performed using a human HNSCC cell line, CAL33, injected into the mouth floor of nude mice. RESULTS: As compared with the control, the combination of Tem and Cet led to the highest tumor inhibition and induced almost complete tumor growth arrest (P = 0.001). Tem significantly enhanced the impact of the Cet-C/F combination on tumor growth (P < 0.001). The highest inhibitory effects of treatments on cell proliferation (Ki67 labeling), MAPK (pP42/44 labeling), and PI3K/AKT/mTOR (pS6R labeling) signaling pathways were found with the Tem-Cet association. CONCLUSION: In this orthotopic HNSCC model, the combination of Tem with Cet produced synergistic effects on tumor growth. These results were corroborated by a strong inhibition of both MAPK and PI3K-mTOR signaling pathways. LEVEL OF EVIDENCE: N/A.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Receptores ErbB/efeitos dos fármacos , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Serina-Treonina Quinases TOR/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Linhagem Celular Tumoral , Cetuximab/farmacologia , Cetuximab/uso terapêutico , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Fluoruracila/farmacologia , Fluoruracila/uso terapêutico , Humanos , Camundongos , Camundongos Nus , Sirolimo/análogos & derivados , Sirolimo/farmacologia , Sirolimo/uso terapêutico
11.
J Immunother ; 35(2): 154-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22306903

RESUMO

There is now substantial evidence that imatinib may affect immune responses, especially those mediated by T lymphocytes. Fas (CD95/Apo-1), a cell death receptor, is a key regulator of the immune system. We have explored the consequences of treatment on the Fas system in chronic myeloid leukemia patients treated with imatinib. In comparison with healthy controls, we found not only a mild blood lymphopenia but also impairment of phytohemagglutinin activation in CD4Fas and CD8Fas lymphocytes of imatinib-treated patients. Moreover, these lymphocyte populations were more sensitive to FasL-induced cell death in relation to an increase in Fas expression at the cell surface. Taken together, these results reveal the role of Fas receptor in the lymphopenia observed in patients treated with imatinib, with potential deleterious consequences on antileukemic responses against this immunogenic hematological malignancy.


Assuntos
Antineoplásicos/efeitos adversos , Apoptose/efeitos dos fármacos , Proteína Ligante Fas/imunologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Piperazinas/efeitos adversos , Pirimidinas/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Apoptose/imunologia , Benzamidas , Separação Celular , Feminino , Citometria de Fluxo , Humanos , Mesilato de Imatinib , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/imunologia , Linfopenia/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Receptor fas/imunologia
13.
Cancer Genet Cytogenet ; 195(1): 12-8, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19837262

RESUMO

Rhabdomyosarcoma (RMS) is the most common pediatric soft tissue sarcoma and rarely occurs in adults. There are six main subtypes, each histologically, clinically, and cytogenetically distinct. Embryonal RMS is characterized by chromosomal gains, usually not associated with any consistent structural anomaly. We describe here a case of embryonal RMS in a 19-year-old female patient. The conventional cytogenetic analysis showed a t(4;22)(q35;q12) translocation as the sole cytogenetic change. Complementary fluorescence in situ hybridization analysis showed that the translocation breakpoints were located in the EWSR1 gene at 22q12 and the region of the DUX4 and FSHMD1A at 4q35. This constitutes a novel example of the high frequency of EWSR1 rearrangements in various types of sarcomas as well as of its ability to fuse with a large variety of partner genes. Because DUX4 is involved in myogenic differentiation and cell-cycle control, the striated muscle differentiation observed in the present case might be a direct consequence of the alteration of the DUX4 region generated by the t(4;22). The involvement of the DUX4 region might represent the genetic hallmark of a novel subclass of small round cell tumors.


Assuntos
Proteínas de Ligação a Calmodulina/genética , Proteínas de Homeodomínio/genética , Distrofia Muscular Facioescapuloumeral/genética , Proteínas de Fusão Oncogênica/genética , Proteínas de Ligação a RNA/genética , Rabdomiossarcoma Embrionário/genética , Adulto , Cromossomos Humanos Par 22 , Cromossomos Humanos Par 4 , Análise Citogenética , Feminino , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Proteínas dos Microfilamentos , Microscopia Eletrônica , Proteínas Nucleares , Proteína EWS de Ligação a RNA , Rabdomiossarcoma Embrionário/patologia , Translocação Genética , Adulto Jovem
14.
Genes Chromosomes Cancer ; 47(11): 971-7, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18663748

RESUMO

Lipomas are frequently characterized by rearrangements resulting in the fusion of the HMGA2 gene (12q14.3) with a variety of partners. Chromosome band 9p22 rearrangements occur in about 1% of lipomas. We report here the molecular cytogenetic analysis of five cases of lipoma with a 9p22 aberration, including the first cytogenetic analysis of a colonic lipoma. Three out of the five cases showed a rearrangement of NFIB at 9p22.3. The NFIB rearrangement involved a fusion with HMGA2 in two cases. We have identified an in-frame fusion of the first three exons of HMGA2 with exon 6 of MSRB3 (12q14.3) and exons 8 and 9 of NFIB by using 3'RACE-PCR in a case of superficial lipoma. In a case of retroperitoneal lipoma we found a fusion of HMGA2 with NFIB by fluorescence in situ hybridization analysis. The colonic lipoma was characterized by a t(9;16;19)(p22;q21;q13) with a rearrangement of NFIB and no rearrangement of HMGA2. NFIB belongs to the nuclear factor I transcription family. It has been previously shown to be fused with HMGA2 in one case of lipoma and to be a recurrent partner of HMGA2 in pleormorphic adenoma of salivary glands. We here demonstrate that NFIB can also be rearranged independently from HMGA2, indicating a potentially important role in lipoma pathobiology. Our findings suggest that the rearrangement of NFIB might be associated with deep-seated lipomas, such as retroperitoneal or gastro-intestinal lipomas.


Assuntos
Aberrações Cromossômicas , Cromossomos Humanos Par 9/genética , Neoplasias do Colo/genética , Lipoma/genética , Fatores de Transcrição NFI/genética , Neoplasias Retroperitoneais/genética , Adulto , Idoso , Sequência de Bases , Neoplasias do Colo/patologia , Feminino , Humanos , Cariotipagem , Lipoma/patologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Fatores de Transcrição NFI/metabolismo , Neoplasias Retroperitoneais/patologia
15.
Biochem J ; 411(1): 33-40, 2008 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-18052924

RESUMO

The epidermis of fish is covered with a layer of mucus, which contributes to the defence of the species against parasites, bacteria and fungi. We have previously extracted glycoproteins from various mucus samples from fish and have shown that they present pore-forming activities well correlated with strong antibacterial properties [Ebran, Julien, Orange, Saglio, Lemaitre and Molle(2000) Biochim. Biophys. Acta 1467, 271-280]. The present study focuses on the 65 kDa glycoprotein, Tr65, from the rainbow trout (Oncorhynchus mykiss, formerly Salmo gairdneri).Enzymatic digestion of Tr65 yielded a fragment pattern with strong homology with that of trout type II cytokeratin. Sequence analysis of the cDNA clone obtained by PCR confirmed this homology. We thus constructed a plasmid to overproduce the recombinant Tr65. We extracted and purified this recombinant Tr65, using it for multichannel and single-channel experiments in azolectin bilayers. Our results with recombinant Tr65 confirmed the pore-forming properties already shown with native antibacterial Tr65. These findings offer new insights into the function of keratin proteins present in various mucosal surfaces of animals and human beings.


Assuntos
Queratinas/fisiologia , Muco/química , Oncorhynchus mykiss/genética , Porosidade , Pele/química , Animais , Sequência de Bases , Clonagem Molecular , DNA Complementar , Epiderme/química , Epiderme/ultraestrutura , Queratinas/genética , Queratinas/imunologia , Muco/imunologia , Oncorhynchus mykiss/imunologia , Fragmentos de Peptídeos , Pele/imunologia , Pele/ultraestrutura
17.
Arch Dermatol ; 143(2): 203-10, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17310000

RESUMO

BACKGROUND: The diagnosis of dermatofibrosarcoma protuberans (DFSP) in childhood is often difficult because of the deceptive appearance of the lesions. Little is known about congenital DFSP, the frequency of which is probably underestimated because the initial lesion may pass unnoticed. OBSERVATIONS: We studied 9 DFSP congenital cases (8 plaques and 1 nodule) initially suspected to be benign lesions. The first biopsies or excisions were performed after a delay of 5(1/2) months to 15 years. All cases were CD34+. Histologic patterns were similar to the DFSP adult classic pattern in 4 cases. One case was a Bednar tumor. The histologic diagnosis of the 4 remaining cases was difficult. The collagen, type I, alpha 1-platelet-derived growth factor beta fusion gene (COL1A1-PDGFB) was detected by means of reverse transcriptase-polymerase chain reaction or fluorescence in situ hybridization. CONCLUSIONS: All cases of congenital DFSP were difficult to identify clinically. The diagnosis was suspected by means of histologic and immunohistochemical evaluation and was confirmed using molecular analyses. This study illustrates the difficulties and pitfalls of the recognition of congenital DFSP and emphasizes the value of immunohistochemical study with anti-CD34 and complementary molecular analysis for all cutaneous spindle cell tumors and plaques in neonates and infants.


Assuntos
Dermatofibrossarcoma/genética , Dermatofibrossarcoma/patologia , Proteínas de Fusão Oncogênica/genética , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Adolescente , Antígenos CD34/metabolismo , Criança , Pré-Escolar , Dermatofibrossarcoma/congênito , Feminino , Humanos , Hibridização in Situ Fluorescente , Lactente , Masculino , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Cutâneas/congênito
18.
Cancer Genet Cytogenet ; 168(2): 155-7, 2006 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-16843106

RESUMO

We present a 10-year-old girl with a pure Bednar tumor (pigmented dermatofibrosarcoma protuberans) of the right shoulder. Cytogenetic analysis demonstrated 47 chromosomes with 2 copies of a derivative chromosome 22, der(22)t(17;22)(q22;q13). Fluorescence in situ hybridization (FISH) analysis demonstrated the COL1A1-PDGFB fusion on both der(22) chromosomes. By RT-PCR and sequencing, we observed a fusion of the COL1A1 exon 41 with PDGFB exon 2. This pure pediatric Bednar tumor in a child, like childhood dermatofibrosarcoma protuberans, had a linear structural abnormality rather than a ring chromosome that is more commonly encountered in adult Bednar and dermatofibrosarcoma protuberans tumors. The underlying molecular abnormality in this pediatric Bednar tumor is the same as in dermatofibrosarcoma protuberans.


Assuntos
Cromossomos Humanos Par 17/genética , Cromossomos Humanos Par 22/genética , Dermatofibrossarcoma/genética , Proteínas de Fusão Oncogênica/genética , Translocação Genética/genética , Sequência de Bases , Criança , Éxons/genética , Feminino , Humanos , Dados de Sequência Molecular
19.
Genetics ; 160(4): 1363-73, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11973293

RESUMO

Chromosomal translocations are common genetic abnormalities found in both leukemias and solid tumors. While much has been learned about the effects of specific translocations on cell proliferation, much less is known about what causes these chromosome rearrangements. This article describes the development and use of a system that genetically selects for rare translocation events using the yeast Saccharomyces cerevisiae. A translocation YAC was created that contains the breakpoint cluster region from the human MLL gene, a gene frequently involved in translocations in leukemia patients, flanked by positive and negative selection markers. A translocation between the YAC and a yeast chromosome, whose breakpoint falls within the MLL DNA, physically separates the markers and forms the basis for the selection. When RAD52 is deleted, essentially all of the selected and screened cells contain simple translocations. The detectable translocation rates are the same in haploids and diploids, although the mechanisms involved and true translocation rates may be distinct. A unique double-strand break induced within the MLL sequences increases the number of detectable translocation events 100- to 1000-fold. This novel system provides a tractable assay for answering basic mechanistic questions about the development of chromosomal translocations.


Assuntos
Saccharomyces cerevisiae/genética , Translocação Genética , Cromossomos Artificiais de Levedura , Eletroforese em Gel de Campo Pulsado , Cariotipagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...