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Query: UMLS:C0025202 (melanoma)
 69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously reported that the human immunodeficiency virus type 1 (HIV-1) regulatory gene vpr induces differentiation of rhabdomyosarcoma (embryonal muscle tumor cell line) cells, an effect that is accompanied by reduced proliferative capacity of the transfected cells. In this report, we examine the effect of Vpr expression on several different tumor cell lines derived from unique lineages. These tumor cells display different patterns of modulated oncogenes including both ras and p53 mutations. Here we demonstrate that the growth of tumor cells in vitro and in vivo is arrested by the expression of HIV-1 Vpr. Expression of Vpr in several human tumor cell lines upon transfection resulted in an accumulation of cells in the G2/M phase of cell cycle with altered cellular morphology, including an increase in adherence, and growth arrest, consistent with a differentiated phenotype. Vpr expression in B78/H1 cells results in a marked reduction in colony formation in vitro and an associated reduction in melanin synthesis by the cells. Vpr-transfected melanoma cells inoculated into syngenic C57BL/6 mice showed a markedly reduced ability to form tumors in vivo. These results suggest that this retroviral regulatory gene has broad tumor suppressor effects, likely mediated by transcriptional regulation of the state of the host cell.
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PMID:In vitro and in vivo tumor growth suppression by HIV-1 Vpr. 905 34

A continuing problem in cytology laboratories is the lack of adequate control material for immunocytochemical testing. Usual control procedures involve testing paraffin-embedded control materials along with the patient specimens. These control materials are fundamentally unlike cytologic preparations. We have developed a method to make control preparations for immunocytochemical analysis using cultured anaplastic cells with known antigenic features from commercial sources. Cell lines included melanoma, rhabdomyosarcoma, T-cell leukemia, and squamous-cell carcinoma. Modified Saccomano and acetone fixation coupled with the cytospin technique enabled good-quality preparations. Cell lines were tested with antibodies for HMB-45, actin, leukocyte common antigen (LCA) and cytokeratin, which avidin-biotin immunoperoxidase and diaminobenzidine (DAB) as chromogens. Our final preparations were easily interpretable with excellent morphologic preservation of cellular detail. Cultured cells provide a superior method for preparing almost unlimited numbers of control slides for immunocytochemistry for laboratories with access to a tissue culture facility.
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PMID:Immunocytochemistry controls using cell culture. 921 10

Animal models of leptomeningeal metastasis (LM) should give insight into pathophysiological mechanisms and allow to evaluate new treatments including their neurotoxicity. Syngeneic models use tumor cells of mouse, rat, rabbit or guinea pig origin. Allogeneic models usually rely on human tumor cells injected into nude mice or rats. A review of the literature revealed 2 (4) different glioma, 3 medulloblastoma, 3 (3) carcinoma, 3 (1) melanoma, 1 rhabdomyosarcoma, 2 (8) leukemia and 2 (2) non-Hodgkin's lymphoma allogeneic (syngeneic) models of LM. These models have been used to study the evolution of LM and to evaluate systemic or intrathecal chemotherapy, intrathecal immunotherapy (interleukin-2, interferon-beta, uncoupled, toxin- or radionuclide-conjugated antibodies), and recently gene therapeutic approaches. On the whole, pathophysiological, therapeutic and neurotoxic findings have been well transferable to the clinical situation. Therefore, it seems rational to preclinically test new treatments in an appropriate animal model of LM before using them in patients.
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PMID:Animal models of leptomeningeal metastasis. 969 72

Hyalinizing clear cell carcinoma (HCCC) is a rare, recently described tumor of salivary gland origin. Differential diagnosis includes benign lesions as clear cell change in a pleomorphic adenoma or in oncocytoma and malignant tumors - i.e. epithelial-myoepithelial carcinoma, polymorphous low-grade adenocarcinoma, mucoepidermoid carcinoma, clear cell acinic carcinoma, clear cell squamous carcinoma, clear cell malignant melanoma, clear cell odontogenic carcinoma, clear cell rhabdomyosarcoma, sebaceous carcinoma and metastasis of renal carcinoma. A favorable prognosis after wide local excision has been evidenced. Three new cases of HCCC (2 in the oral cavity and 1 in the parotid gland) are presented.
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PMID:Hyalinizing clear cell carcinoma of the oral cavity and of the parotid gland. 1124 74

The sinonasal undifferentiated carcinoma (SNUC) is an aggressive and rare neoplasm arising in the nasal cavity and the paranasal sinuses. To date, over 50 cases of histologically proven SNUCs have been reported since its original description in 1986. Presenting symptoms include facial pain, nasal obstruction, diplopia, epistaxis, proptosis, and periorbital swelling. The histologic features of this neoplasm include cohesive cells arranged in nests, ribbons, and trabeculae. The cells exhibit hyperchromatic nuclei and a high nuclear to cytoplasmic ratio. A brisk mitotic rate, tumor necrosis, and vascular invasion are prominent features. Confirming the diagnosis of SNUC at the light microscopic level can be challenging, since the microscopic differential diagnosis includes olfactory neuroblastoma, rhabdomyosarcoma, undifferentiated nasopharyngeal carcinoma (lymphoepithelioma), malignant lymphoma, malignant melanoma, and neuroendocrine (small cell undifferentiated; oat cell) carcinoma. Sinonasal undifferentiated carcinoma can be differentiated from these other neoplasms by correlating clinical, light microscopic, histochemical, immunohistochemical, and ultrastructural characteristics. Aggressive, multimodal therapy can provide the best opportunity for local control of this neoplastic process, but the optimal treatment has yet to be determined.
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PMID:Sinonasal undifferentiated carcinoma: a distinctive clinicopathologic entity. 1056 93

A case of melanotic neuroectodermal tumour of infancy is described. The pre-operative diagnosis was made on cytological material obtained by fine needle aspiration. The patient was a three-month-old male infant with a rapidly growing maxillary tumour mass that also involved the pterygomaxillary fossae and the floor of the orbit. In addition to the typical clinical presentation, the cytology is also distinctive showing a dual population of small neuroblastic cells and large melanin-containing epithelial cells. Histological, immunohistochemical and electron microscopic examination of the excised mass confirmed the initial diagnosis. The pre-operative distinction of this tumour from other small round cell tumours of infancy (rhabdomyosarcoma, neuroblastoma, melanoma and lymphoma), is essential in order to plan the most complete resection therefore reducing the possibilities of tumour recurrence. This tumour belongs to a field of pathology with which many otolaryngologists may not be familiar.
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PMID:Fine needle aspiration in the pre-operative diagnosis of melanotic neuroectodermal tumour of infancy. 1060 95

The term "small round-cell tumor" describes a group of highly aggressive malignant tumors composed of relatively small and monotonous undifferentiated cells with high nuclear to cytoplasmic ratios. This group includes Ewing's sarcoma (ES), peripheral neuroepithelioma (aka, primitive neuroectodermal tumor or extraskeletal ES), peripheral neuroblastoma ("classic-type"), rhabdomyosarcoma, desmoplastic small round-cell tumor, lymphoma, leukemia, small-cell osteosarcoma, small-cell carcinoma (either undifferentiated or neuroendocrine), olfactory neuroblastoma, cutaneous neuroendocrine carcinoma (aka, Merkel-cell carcinoma), small-cell melanoma, and mesenchymal chondrosarcoma. Their clinical presentations often overlap, thus making a definitive diagnosis problematic in some cases. Yet, a clear understanding of their clinicopathologic features usually allows for a confident diagnosis, especially if immunohistochemistry is used. The following is a review of the immunohistochemistry of this small round-cell tumor group.
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PMID:Immunohistochemistry of small round-cell tumors. 1096 7

The three major categories of nonmammary malignancies of the breast include primary and secondary lymphoreticular malignancy, primary and secondary sarcoma, and hematogenous metastasis. This article describes the imaging features of 35 nonmammary malignancies of the breast and axilla with histopathologic confirmation. These include primary and secondary breast lymphoma, primary axillary nodal lymphoma, metastatic acute lymphatic leukemia, metastatic plasmacytoma, granulocytic sarcoma, primary angiosarcoma, metastatic rhabdomyosarcoma, hematogenous metastasis from primary lung, ovarian, cervical, thyroid, and colonic carcinoma, malignant melanoma, carcinoma of the nasal cavity, and adenocarcinoma of unknown primary. Wherever possible, correlation between mammography and ultrasound, computed tomography (CT), and/or magnetic resonance (MR) imaging is made.
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PMID:Nonmammary malignancies of the breast: ultrasound, CT, and MRI. 1107 18

Deregulated expression of the transcription factor PAX3 was observed previously in several tumors like rhabdomyosarcoma and Ewing's sarcoma. Because PAX3 expression is also found in pluripotent neural crest cells, we investigated whether melanomas, tumors derived mostly from cutaneous intraepidermal melanocytes, might show deregulated PAX3 expression. Using a specific and sensitive reverse transcription-PCR, we detected PAX3 mRNA in 77% (27 of 35) of primary cultured melanomas. These results could be confirmed by direct in situ hybridization on the corresponding tissue sections where PAX3 expression was unambiguously confined to tumor cells and not detected in surrounding normal tissue, normal skin sections, or sections of benign lesions. Furthermore, down-regulation of PAX3 expression achieved through a specific antisense oligonucleotide-based treatment resulted in > 70% of dead cells specifically in PAX3-positive melanomas. Annexin V staining confirmed that primary melanoma cells underwent apoptosis after treatment These experiments suggest that in situ hybridization of PAX3 on paraffin-embedded tissue may represent a novel means to identify melanoma cell lesions, which appear to become dependent on expression of this deregulated transcription factor.
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PMID:PAX3 is expressed in human melanomas and contributes to tumor cell survival. 1122 62

Low-affinity nerve growth factor receptor (p75) is a member of the tumor necrosis factor receptor family. It may modulate the binding of nerve growth factor (NGF) to the functional high-affinity receptor tyrosine kinase (trk) A. NGF is thought to be responsible for growth, apoptosis, and function of the nervous system. The presence of this receptor (p75) was determined in a large group of neural and nonneural tumors and fetal and adult tissues. One thousand one hundred fifty tumors were analyzed with monoclonal antibody for p75, along with selected normal fetal and adult tissues. Immunoreactivity for p75 was present in adult pericytes, perivascular fibroblasts, basal cells of several types of epithelia, perineurial cells, and dendritic reticulum cells. Additionally, a wide zone of subepithelial mesenchyme and skeletal muscle were positive in the first-trimester fetus, but were diminished or negative in the adult. Consistently positive nonneural mesenchymal tumors included dermatofibrosarcoma protuberans (DFSP), embryonal and alveolar rhabdomyosarcoma, synovial sarcoma, and spindle cell hemangio(endotheli)oma. Schwann cell tumors, ganglioneuroma, granular cell tumor, and malignant peripheral nerve sheath tumor (MPNST) were also p75 positive. Mesenchymal nonneural tumors that were variably positive (32% to 69%) for p75 included fibrosarcoma variants, solitary fibrous tumor, hemangiopericytoma, spindle cell lipoma, Ewing's sarcoma, mesenchymal chondrosarcoma, and malignant melanoma. Nervous system tumors such as paragangliomas, neuroblastoma, meningioma, and perineurioma and nonneural mesenchymal tumors, including extraskeletal osteosarcoma, benign fibrous histiocytomas, fibromas, alveolar soft part sarcoma, epithelioid sarcoma, smooth muscle and gastrointestinal stromal tumors, and angiosarcomas, were almost always negative for p75. Epithelial tumors that were consistently positive included mixed tumor and adenoid cystic carcinoma, whereas mesothelioma, adenocarcinomas, and most squamous cell carcinomas were negative. p75 is not a specific marker for nerve sheath tumors. It is present in a variety of other mesenchymal tumors including synovial sarcoma and in CD34-positive tumors such as DFSP, spindle cell lipoma, and hemangiopericytoma. The presence of p75 in nonneural tumors such as DFSP and rhabdomyosarcoma mimic its presence in early fetal mesenchyme and skeletal muscle, suggesting oncofetal expression in these tumors. p75 may be useful to distinguish DFSP from benign fibrous histiocytoma.
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PMID:Low-affinity nerve growth factor receptor (p75) in dermatofibrosarcoma protuberans and other nonneural tumors: a study of 1,150 tumors and fetal and adult normal tissues. 1156 28


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