Search results for "sarcoma"

Atrophic dermatofibrosarcoma protuberans with the fusion gene COL1A1-PDGFB

2008

Gene Signatures in Gastrointestinal Stromal Tumors

2011

Gastrointestinal stromal tumors (GISTs) constitute a rare heterogeneous group of the most common mesenchymal neoplasm of gastrointestinal tract (GI). GISTs have emerged during the recent years as a distinct sarcoma entity due to advances in the understanding of molecular mechanism of their pathogenesis. They are believed to originate from precursors shared with interstitial cells of Cajal (ICC) – the pacemaker cells of the gut (for which CD117 antigen is the immunohistochemical marker), and they may arise along all GI (most commonly in the stomach or the small bowel) or rarely elsewhere. Their biological behavior is difficult to predict, ranging from clinically benign to malignant. The trea…

Urokinase Plasminogen Activator and Gelatinases Are Associated with Membrane Vesicles Shed by Human HT1080 Fibrosarcoma Cells

1997

Membrane vesicles are shed by tumor cells both in vivo and in vitro. Although their functions are not well understood, it has been proposed that they may play multiple roles in tumor progression. We characterized membrane vesicles from human HT1080 fibrosarcoma cell cultures for the presence of proteinases involved in tumor invasion. By gelatin zymography and Western blotting, these vesicles showed major bands corresponding to the zymogen and active forms of gelatinase B (MMP-9) and gelatinase A (MMP-2) and to the MMP-9. tissue inhibitor of metalloproteinase 1 complex. Both gelatinases appeared to be associated with the vesicle membrane. HT1080 cell vesicles also showed a strong, plasminoge…

miR-486-5p expression is regulated by DNA methylation in osteosarcoma.

2022

Abstract Background Osteosarcoma is the most common primary malignant tumour of bone occurring in children and young adolescents and is characterised by complex genetic and epigenetic changes. The miRNA miR-486-5p has been shown to be downregulated in osteosarcoma and in cancer in general. Results To investigate if the mir-486 locus is epigenetically regulated, we integrated DNA methylation and miR-486-5p expression data using cohorts of osteosarcoma cell lines and patient samples. A CpG island in the promoter of the ANK1 host gene of mir-486 was shown to be highly methylated in osteosarcoma cell lines as determined by methylation-specific PCR and direct bisulfite sequencing. High methylati…

New type of chimeric fusion product between theEWS andATF1 genes in clear cell sarcoma (malignant melanoma of soft parts)

1998

We report a new case of clear cell sarcoma (CCS) harboring the t(12;22)(q13;q12). Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed the presence of a chimeric transcript between the EWS and ATF1 genes, both in primary and metastatic tissue. Sequencing studies disclosed an in-frame fusion between EWS gene codon 265 and ATF1 gene codon 110. This breakpoint has not been reported previously and indicates an important in vivo loss of EWS and ATF1 gene domains, which could be associated with the unusually aggressive behavior of this tumor. Genes Chromosomes Cancer 23:358–360, 1998. © 1998 Wiley-Liss, Inc.

Genomic characterization of undifferentiated sarcomatoid carcinoma of the pancreas

2022

Undifferentiated sarcomatoid carcinoma (USC) of the pancreas is a rare but especially aggressive variant of pancreatic ductal adenocarcinoma (PDAC), composed of at least 80% of sarcomatoid cells. This study aimed to elucidate its clinicopathological and molecular features. The study cohort included 10 patients with pancreatic USC. Clinicopathological parameters were determined for each patient. The molecular profile was investigated using next-generation sequencing (NGS). Histologically, all tumors were hypercellular neoplasms with spindle-shaped or sarcomatoid cells. All patients showed vascular and perineural invasion. Most patients had a poor prognosis. NGS showed important similarities …

Genotypic analysis at multiple loci across Kaposi's sarcoma herpesvirus (KSHV) DNA molecules: clustering patterns, novel variants and chimerism

2001

Abstract Background: the genomes of human Kaposi's sarcoma-associated herpesvirus (KSHV) display several levels of DNA sequence heterogeneity and subgrouping that show distinctive clustering patterns in related human populations. The four major subtype patterns for the hypervariable ORF-K1 protein correlate closely with the principal diasporas resulting from the migration of modern humans out of East Africa and suggest that KSHV is an ancient human virus that is transmitted primarily in a familial fashion with consequent very low recombination rates. However, chimeric genomes have also been detected, especially with regard to the presence of P versus M alleles of the ORF-K15 gene. Objective…

Sarcoma de estroma endometrial. Estudio clinicopatológico e inmunofenotípico de 5 casos

2007

Introducción: El sarcoma de estroma endometrial uterino es un tumor muy poco frecuente con una incidencia de 0,4 -3,4 por 100.000 mujeres, comprende menos del 1% de tumores malignos ginecológicos y el 2-5% de tumores malignos uterinos, siendo el tercer sarcoma en frecuencia después del carcinosarcoma y el leiomiosarcoma. Material y métodos: Presentamos cinco casos de sarcoma de estroma endometrial diagnosticados en un periodo de siete años con la evolución clínica de las pacientes. Resultados: Immunohistoquímicamente, estos tumores expresaban vimentina, receptores hormonales, CD10 y p53 (sarcomas de alto grado), siendo los marcadores musculares, la CK, el c-kit y ALK negativos. De estos cin…

Ultrastructure of vascular neoplasms

1982

Summary The vascular tumors are morphologically recognized by their ability to configurate complete or atypical angiomatous structures. Based on our personal experience of 42 cases of benign and malignant angiomatous tumors, we discussed several aspects of their histogenesis and its morphology when studied with transmission and scanning electron microscopy. Therefore, a survey of the normal histology was developed based not only on normal adult histological structures but also on reparative tissues, as in chronic inflammatory reactions of the gingival mucosa, regenerative tissue of wounds and in chronic osteomyelitis. Supported by morphological arguments, we postulate the existence of sever…

Immunohistochemical Study as a Tool in Differential Diagnosis of Pediatric Malignant Rhabdoid Tumor

2010

Malignant rhabdoid tumors (MRTs) are aggressive childhood neoplasms, occurring mainly in the kidney and brain. We describe 2 unusual cases of extrarenal and noncranial location (liver and soft tissue with dissemination) mimicking hepatoblastoma, neuroblastoma or Ewing sarcoma. Both cases revealed a polyphenotypic profile, combined with cytokeratin, vimentin, and CD99 expression. INI1/BAF-47 showed negative protein nuclear expression in both cases, suggesting a diagnosis of MRT. An extensive immunohistochemical panel was performed to exclude pediatric tumors reminiscent of MRT. The genetic studies failed to detected MYCN amplification, 11q23 deletion, and EWS break-apart positivity. No alter…