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Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Despite the use of sentinel node biopsy techniques, the search continues for other strategies to improve the accuracy of estimating prognosis in melanoma patients. Various biomarkers have previously been studied for use in this role, but none has yet achieved acceptance in routine practice. We have applied the novel technology of tissue microarray for the high throughput screening of a cohort of 120 primary cutaneous melanoma specimens for expression of the transmembrane glycoprotein CD44, splice variant 3 (v3), which has previously been implicated in tumor progression. A highly significant correlation between CD44v3 expression and Breslow thickness, Clark's level and patient age was demonstrated (Spearman correlation p < 0.001). Regarding clinical outcome, CD44v3 expression was shown to be significantly associated with better outcome (chi(2) = 7.2219, p = 0.0072). Furthermore, subgroup analysis revealed a sequentially improved survival probability associated with the intensity of CD44v3 staining (chi(2) = 12.5162, p = 0.0058). Analysis in a Cox multivariate model, however, did not show CD44v3 to be independently predictive of prognosis. The implications of these findings are considered, and the use of CD44v3 as a potential prognostic marker or a target for therapeutic manipulation are discussed.
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PMID:CD44v3 levels in primary cutaneous melanoma are predictive of prognosis: assessment by the use of tissue microarray. 1618 82

New methods of study are necessary to define the homeostatic mechanisms that regulate stem cell properties and to determine the possible epigenetic influence of the stem cell microenvironment on the phenotype of tumor cells. We recently demonstrated that the tumorgenicity of aggressive cutaneous melanoma cells can be abrogated by the zebrafish embryonic microenvironment. We have developed a three-dimensional (3D) model, as a corollary of these findings, that allows melanoma cells to be exposed to the microenvironment of human embryonic stem cells (hESCs). Using this methodology, we determined that hESC microenvironments can dramatically influence the behavior of aggressive melanoma cells. Specifically, exposure of tumor cells to H1- or HSF-6-hESC matrices induced a melanocyte-like phenotype with the ability to form colonies similar to hESCs. Furthermore, melanoma cells were less invasive after culture on hESC microenvironments. These findings demonstrate the utility of this 3D model for studying the unique factors deposited by hESCs and for investigating the epigenetic effects that stem cell microenvironments may have on tumor progression.
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PMID:A three-dimensional model to study the epigenetic effects induced by the microenvironment of human embryonic stem cells. 1629 74

The care of patients who have cutaneous melanoma (CM) has undergone a dramatic change during the past five decades. In an increasing majority of cases, CM is being discovered in a premetastatic phase of tumor progression. Most patients are being treated in the ambulatory setting with a minimum of inconvenience and economic cost, and modest re-excision margins have largely replaced the mutilating surgical exonerations that were once standard only four decades ago. Histopathologic assessment of the primary tumor is the most widely used staging procedure to determine who is most likely to develop metastatic disease. For patients who develop distant metastases, there is no therapy currently available, based on large-scale randomized trials, that will prolong patient survival. Therefore, establishing an early diagnosis in a premetastatic phase of tumor development must be the overriding goal of any intervention strategy that seeks to reduce CM-related mortality. Unfortunately, as a result of public messages that emphasize the role of ultraviolet radiation (UVR) exposure in tumor development, most general physicians and lay people believe that most if not all cases of CM are the direct result of UVR exposure. In fact, we do not know the case fraction of CM directly attributable to UVR, and the unintended consequences of current messages directly linking UVR exposure and CM development may be thwarting the primary intervention goal of reducing tumor-related mortality. More likely to have an immediate positive impact on CM-related mortality are public messages that encourage skin awareness and self-examination by patients, total skin screening examinations by physicians during routine care, and periodic lifetime surveillance of patients determined to have a high CM risk based on identifiable historic and phenotypic traits.
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PMID:Cutaneous melanoma and intervention strategies to reduce tumor-related mortality: what we know, what we don't know, and what we think we know that isn't so. 1640 70

Angiogenesis is essential for tumor progression and metastasis; however, the angiogenesis regulators that are biologically relevant for melanoma are still unknown. In this study, we analyzed the circulating serum levels of potent angiogenic factors, including vascular endothelial growth factor (VEGF), angiogenin, transforming growth factor-beta1 and VEGF receptors, VEGFR1 and VEGFR2, in human melanoma patients. One hundred and fourteen patients with histopathologically verified cutaneous melanoma at different stages and 30 healthy controls were investigated. Serum levels of angiogenic factors and VEGF receptors were quantitatively analyzed by solid-phase enzyme-linked immunosorbent assay. The age of the patients (61 men and 53 women) ranged from 18 to 80 years; median age was 51 years. Serum transforming growth factor-beta1 (P < 0.001), VEGF (P = 0.006) and VEGFR1 (P = 0.007) levels were significantly higher in patients with melanoma than in the control group. No significant differences, however, exist in the serum angiogenin and VEGFR2 levels between melanoma patients and the controls. The positive correlations of elevated serum levels of transforming growth factor-beta1, VEGF and VEGFR1 with advanced stages of disease were found. Significant relationship was found only between serum levels of VEGF and VEGFR2. Elevated serum transforming growth factor-beta1 (P < 0.001) and VEGF levels (P = 0.0012) were found to be poor prognostic factors. Serum level of angiogenin and VEGF receptors, however, had no effect on survival. Our data suggest that the angiogenic serum factors, including VEGF, transforming growth factor-beta1 and VEGFR1, but not angiogenin and VEGFR2 were increased in melanoma patients, especially associated with advanced disease stages. The mechanism of VEGF regulation of angiogenesis may in part be due to enhanced proliferation of VEGFRs, especially VEGFR1.
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PMID:Circulating serum levels of angiogenic factors and vascular endothelial growth factor receptors 1 and 2 in melanoma patients. 1701 89

The cornerstone of the concept of immunosurveillance in cancer should be the experimental demonstration of immune responses able to alter the course of in vivo spontaneous tumor progression. Elegant genetic manipulation of the mouse immune system has proved this tenet. In parallel, progress in understanding human T cell mediated immunity has allowed to document the existence in cancer patients of naturally acquired T cell responses to molecularly defined tumor antigens. Various attributes of cutaneous melanoma tumors, notably their adaptability to in vitro tissue culture conditions, have contributed to convert this tumor in the prototype for studies of human antitumor immune responses. As a consequence, the first human cytolytic T lymphocyte (CTL)-defined tumor antigen and numerous others have been identified using lymphocyte material from patients bearing this tumor, detailed analyses of specific T cell responses have been reported and a relatively large number of clinical trials of vaccination have been performed in the last 15 years. Thus, the "melanoma model" continues to provide valuable insights to guide the development of clinically effective cancer therapies based on the recruitment of the immune system. This chapter reviews recent knowledge on human CD8 and CD4 T cell responses to melanoma antigens.
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PMID:The human T cell response to melanoma antigens. 1714 5

Malignant melanoma is one of the most aggressive and invasive metastatic tumors derived from melanocytes that have undergone malignant transformation by acquisition of genetic and epigenetic alterations. Oligonucleotide microarray-based screening of distinct stages in the tumor progression model of cutaneous melanoma identified ASK/Dbf4, as a novel determinant for melanoma development. Quantitative real-time polymerase chain reaction-based confirmation of ASK/Dbf4 on a series of benign nevi, dysplastic nevi, primary cutaneous melanomas and cutaneous melanoma metastases; and a number of other controls using normal human melanocytes as calibrator not only revealed a melanoma-specific over-expression but also revealed that higher ASK/Dbf4-expressing melanomas were associated with lower relapse-free survival. Additionally, we also confirmed the observed over-expression of ASK/Dbf4 in melanoma using western blot analysis and immunohistochemistry. As ASK/Dbf4 is known to be a cyclin-like regulatory subunit of mammalian Cdc7 from the studies in yeast, the present study investigated its role in melanoma cells. In keeping with its expected role, our data suggest that up-regulated ASK/Dbf4 is localized in the nucleus and binds to human Cdc7 to form Cdc7-ASK/Dbf4 complexes in several analyzed melanoma cell lines. Further, we demonstrate that small interfering RNA-mediated depletion of ASK/Dbf4 retarded melanoma cell survival and proliferation. In summary, we report the differential regulation of a novel gene, namely ASK/Dbf4, in melanoma and suggest that up-regulation of ASK/Dbf4 is a novel molecular determinant with prognostic relevance that confers a proliferative advantage in cutaneous melanoma.
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PMID:Identification and functional characterization of ASK/Dbf4, a novel cell survival gene in cutaneous melanoma with prognostic relevance. 1776 77

DNA microarray technology is a versatile platform that allows rapid genetic analysis to take place on a genome-wide scale and has revolutionized the way cancers are studied. This platform has enabled researchers to characterize mechanisms central to tumorigenesis and understand important molecular events in the multi-step tumor progression model of cutaneous melanoma and other cancers. In melanoma, multiple global gene expression profiling studies using various DNA microarray platforms and various experimental designs have been performed. Each study has been able to capture and characterize either the involvement of a novel pathway or a novel cause-effect-relationship. The use of microarrays to define subclasses, to identify differentially regulated genes within a mutational context to analyze epigenetically regulated genes has resulted in an unprecedented understanding of the biology of cutaneous melanoma that may lead to more accurate diagnosis, more comprehensive prognosis, prediction and more effective therapeutic interventions. Related DNA microarray platforms like array-comparative genomic hybridization (CGH) have also been instrumental to identify many non-random chromosomal alterations; however, studies identifying validated targets as a result of CGH are limited. Thus, there exists significant opportunity to discover novel melanoma genes and translate such discoveries into meaningful clinical endpoints. In this review, we focus on various DNA microarray-based studies performed in cutaneous melanoma and summarize our current understanding of the genetics and biology of melanoma progression derived from accumulating genomic information.
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PMID:Cutaneous melanoma: fishing with chips. 1847 22

RET proto-oncogene encodes a receptor tyrosine kinase whose ligand is glial cell line-derived neurotrophic factor (GDNF), and its polymorphism at G691S juxtamembrane region (RETp) is a germline polymorphism. Cutaneous melanomas, particularly the desmoplastic subtype, are highly neurotropic; thus we sought to determine the frequency of RETp in cutaneous melanoma and its functional responsiveness to GDNF. RETp was assessed in 71 non-desmoplastic cutaneous melanomas (non-DMs) and 70 desmoplastic melanomas (DMs). Melanoma cell lines with RETp, RET wild type (RETwt), BRAF V600E mutation (BRAFmt) or BRAF wild type (BRAFwt) were assessed for functional activity. RETp frequency was significantly higher in DMs (61%) than in non-DMs (31%, P<0.001). BRAFmt was detected in only 11% of DMs. GDNF stimulation significantly amplified cell proliferation, migration and invasion in RETp, but not in RETwt melanoma cells. GDNF stimulation of RETp cell lines enhanced phosphorylation of extracellular signal-regulated kinase (ERK) and Akt of the RET-RAS-RAF-ERK and RET-phosphatidylinositol 3-kinase (PI3K)-Akt pathways, respectively. GDNF response of RETp cells in signal transduction and other functional studies were not affected by BRAFmt. The study demonstrates that RETp is frequently found in cutaneous melanoma, particularly desmoplastic subtypes, and responds to GDNF inducing events favorable for tumor progression.
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PMID:Functional RET G691S polymorphism in cutaneous malignant melanoma. 1956 46

Fatty acid-binding protein-7 (FABP7) has been shown to be expressed in cutaneous melanoma; however, its role in tumor progression is unclear. Expression of FABP7 was assessed during melanoma progression through assessment of various clinicopathology stages of primary tumor progression and metastasis. FABP7 mRNA was highly expressed in 60 of 87 (69%) primary melanomas, compared with significant (P<0.0001) reduction in 13 of 68 (19%) metastatic melanomas. Analysis of 37 paired primary and metastatic melanomas by immunohistochemistry with anti-FABP7 Ab showed 73 and 27% positivity, respectively (P<0.001). FABP7 detection of metastatic tissues was inversely correlated with relapse-free (P<0.0001) and overall (P<0.0001) survival. To examine FABP7 expression loss in advanced melanomas, loss of heterozygosity (LOH) was assessed using microsatellite markers encompassing the FABP7 gene. LOH was identified in 10 of 20 (50%) metastatic melanomas at 6q22.31, compared with 0 of 14 primary melanomas (P=0.0017). FABP7 as a surrogate biomarker for circulating tumor cells (CTCs) in the blood was assessed by quantitative real-time (qRT)-PCR from melanoma patients' blood (n=134). Assessment of patients' blood showed that FABP7(+) CTC decreased with disease progression. FABP7 may function as a tumor progression gene and can be used as a potential diagnostic biomarker of early-stage melanoma systemic spreading in blood.
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PMID:Aberrant fatty acid-binding protein-7 gene expression in cutaneous malignant melanoma. 1958 92

The clinical diagnosis of cutaneous melanoma always calls for histological confirmation. In addition to the recognition of the classic aspects of the neoplasm, immunohistochemistry is determinant, in particular in the assessment of the size of the replicative compartment. Generally, the proliferation rate is indicative of the neoplastic progression and is related to the clinical growth rate of the neoplasm. It allows to distinguish high risk melanomas showing a high growth rate from those of lower malignancy associated with a restricted growth rate. In melanoma, the recruitment and progression of neoplastic cells in the cell cycle of proliferation have lost some of their controls that are normally processed by a series of key regulatory molecules. In addition, the apoptotic pathway counteracting any hyperproliferative activity is released of the dependency of specific regulated molecular mechanisms. This review summarizes the current knowledge on key molecular components involved in the deregulation of the growth fraction, cell proliferation and apoptosis in melanocytic neoplasms. The implication of cyclins and of the mitogen-activated protein kinase pathways are scrutinized. The involvement of neoplastic stem cells in the metastatic process is also discussed.
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PMID:Molecular pathways supporting the proliferation staging of malignant melanoma (review). 1963 20


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