Navegando por Assunto "aCGH"

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Acesso aberto (Open Access)
Caracterização do genoma de tumores bem diferenciados da tireóide por hibridização genômica comparativa em matriz (aCGH)
(Universidade Federal do Pará, 2014-03-31) ALMEIDA, Deise Cibele Nunes de; OLIVEIRA, Edivaldo Herculano Correa de; http://lattes.cnpq.br/0094007714707651
More than 95% of thyroid gland malignancies are well-differentiated tumors. Preoperative diagnosis accuracy for papillary carcinomas, based on FNAC (Fine Needle Aspiration Cytology) and ultrasound screenings, has become nearly 100%. Nevertheless, when follicular neoplasm diagnosis is concerned, this reality is quite different. Using current preoperative screening tools, 60 – 80% of patients suspected to present follicular thyroid cancer, when operated turn out to suffer from benign disease. Therefore, in an effort to improve these results, genomic analysis of Copy Number Variations (CNV) that may more precisely differentiate follicular tumor from other thyroid conditions were carried out in 13 patients (3 bearing goiters, 2 hyperplasias, 4 follicular adenomas, 4 follicular carcinomas, 1 healthy individual). CNVs were tracked through aCGH method in order to detect follicular carcinoma most accurately. Results were compared with classic papillary carcinoma (4 subjects) and follicular variant (2 subjects). Samples demonstrated 725 CNVs, 703 of which belonging to patients with disease. Among these, 18 most frequent regions were selected. Patterns of amplification were more frequent in younger patients, while deletions were more frequent in the elder ones. Carcinoma patients presented very close CNV rates. Also, exclusive patterns of chromosomes 8 and 12 alterations were noticed in follicular carcinoma. Thus, it is possible to conclude that thyroid follicular carcinoma is a condition comprehending exclusive patterns of alterations, and progression of this disease is not related to follicular adenomas. Finally, regions -8p22 and 12p13.32-p12.33 were detected in 100% and 75% of samples respectively, therefore, may be deemed as possible tumoral markers.
Acesso aberto (Open Access)
Estabelecimento e caracterização citogenética de linhagem celular de carcinoma adenoide cístico
(Universidade Federal do Pará, 2019-12-16) SILVA, Fernanda Jardim da; CALCAGNO, Danielle Queiroz; http://lattes.cnpq.br/1326603355062154; https://orcid.org/0000-0002-4429-2573
Adenoid cystic carcinoma (ACC) is a rare neoplasm that mainly affects the head and neck regions, especially salivary glands. Growth is slow, but with but with a propensity to perineural invasion, local postoperative recurrence and metastasis. The most used treatment for this type of tumor is surgery followed by postoperative radiotherapy. The molecular characteristics of ACC are unclear, and unfortunately, the rarity of this type tumor limits to obtain in vitro and in vivo models that contribute in the investigation of pathogenesis and more efficient treatments. In the present study, a cell line was established and characterized for the evaluation of anticancer molecules. For this, it was obtained tissue samples of ACC off the tubular histological subtype from the retromolar trigone and a blood sample from a 59-year-old female patient. Array Comparative Genomic Hybridization (aCGH) performed molecular cytogenetic characterization in tumor tissue and cell line, while blood was genotyped for ancestry. Cell culture established from the collected tumor tissue showed rapid growth of tumor colonies from passage 18, stabilizing at passage 30. Blood genotyping revealed an ancestral contribution of 19% Amerindians, 31.5% Europeans and 49.5% of blacks. In cytogenetic analysis, gains were observed in loci harboring important genes such as EGFR (7p22.1-p11.2), BRAF (7q32.3-q34), HER2 (17q12-q21.2) and SMARCA1 (xq25-q27.1). Also in the lineage, loss (6q23.3-q25.1, PLAGL1 gene locus) and deletion (9p21.3-p21.1, CDKN2A/B gene locus) were observed; In tissue, only gains were observed (9q34.3, NOTCH1 locus and 5q32, PDGFRβ locus). The loss in 19p13.3-p12, locus of the CDKN2D gene, stands out as a common event in both samples. These findings corroborate other studies in the literature and make the established lineage a good in vitro model that can assist in the investigation of the pathogenesis of CAC and the basic research for new therapeutic modalities.