Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: UMLS:C0278883 (metastatic melanoma)
6,224 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Adhesion molecules are substances which are involved in the interactions between cells, and between cells and the extracellular matrix in both benign and malignant tissues. Two members of this group--intercellular adhesion molecule-1 (ICAM-1) and MUC18--have previously been found to be expressed on melanoma; however, studies seeking a correlation between expression and metastatic behaviour have yielded conflicting results. In this study we investigated the expression of these two antigens and that of a number of other adhesion molecules [VCAM-1, ELAM, and the neural cell adhesion molecule (NCAM)] on a range of benign and malignant melanocytic lesions. Both ICAM-1 and MUC18 were found on a high percentage of all melanocytic lesions including benign naevi. VCAM-1 was found to be expressed on 79 per cent of benign naevi, 62 per cent of primary melanomas less than 1.5 mm in depth, and 6 per cent of thick primaries. The antigen was present on 14 per cent of lymph node metastases and on no extranodal deposits. This suggests that loss of melanoma cell adhesion mediated by VCAM-1 may be important in the development of metastatic melanoma.
...
PMID:A study of adhesion molecules as markers of progression in malignant melanoma. 137 91

The cell-cell adhesion receptor, Mel-CAM/MUC18, is highly expressed on metastatic melanoma cells and is also detectable on primary melanomas but not on normal melanocytes. Previous studies have shown that increased Mel-CAM/MUC18 expression correlates with tumor thickness and metastatic potential. We show here that normal melanocytes and nevus cells in culture express Mel-CAM/MUC18, but expression is down-regulated when cells are co-cultured with keratinocytes. Such keratinocyte-mediated regulation of Mel-CAM/MUC18 expression on melanocytes, nevus cells, and early melanomas can also be demonstrated in situ in patients' specimens. On the other hand, melanoma cells from primary and metastatic lesions constitutively express Mel-CAM/MUC18, and keratinocytes have no modulatory effect. These results suggest that contact between keratinocytes and human melanocytic cells modulates Mel-CAM/MUC18 expression, raising the possibility that escape from keratinocyte control during melanoma development leads to expression of antigens that contribute to the malignant phenotype.
...
PMID:Regulation of Mel-CAM/MUC18 expression on melanocytes of different stages of tumor progression by normal keratinocytes. 794 74

Despite the importance of bone marrow stromal cells in hemopoiesis, the profile of surface molecule expression is relatively poorly understood. Mice were immunized with cultured human bone marrow stromal cells in order to raise monoclonal antibodies to novel cell surface molecules, which might be involved in interactions with hemopoietic cells. Three antibodies, WM85, CC9 and EB4 were produced, and were found to identify a 100-110 kDa antigen on bone marrow fibroblasts. Molecular cloning revealed the molecule to be MUC18 (CD146), a member of the immunoglobulin superfamily, previously described as a marker of metastatic melanoma. In addition to the expected expression on melanoma cell lines and endothelial cells, a number of human leukemic cell lines were found to express MUC18, including all six T leukemia lines tested, one of five B lineage lines and one of four myeloid lines. Analysis of bone marrow samples from patients revealed positivity in 20% of B lineage ALL (n = 20), one of three T-ALL, 15% of AML (n = 13) and 43% of various B lymphoproliferative disorders (n = 7). No apparent reactivity was observed with mononuclear cells from normal peripheral blood or bone marrow, including candidate hemopoietic stem cells characterized by their expression of the CD34 antigen. However, positive selection of bone marrow mononuclear cells labeled with MUC18 antibody revealed a rare subpopulation (<1%) containing more than 90% of the stromal precursors identified in fibroblast colony-forming assays. The structure and tissue distribution of MUC18 suggest a functional role in regulation of hemopoiesis.
...
PMID:MUC18, a member of the immunoglobulin superfamily, is expressed on bone marrow fibroblasts and a subset of hematological malignancies. 952 37

The melanoma cell adhesion molecule was identified as a human melanoma-associated antigen that increases in expression as tumors increase in thickness and begin to acquire metastatic potential. Clinical and experimental evidences suggest that the development of metastatic capacity might be the consequence of increased melanoma cell adhesion molecule expression. The mechanisms for upregulation of the melanoma cell adhesion molecule during melanoma progression are, however, still poorly understood. In this study, we show that melanoma cell adhesion molecule expression is tightly regulated at the transcriptional level. Using a combination of CAT reporter assays and semiquantitative reverse transcriptase-polymerase chain reaction, we observed that cyclic adenosine monophosphate significantly increases transcription of the melanoma cell adhesion molecule in nonmetastatic melanoma cells. In metastatic cells, transcription of the gene was constitutive and could not be further increased by cyclic adenosine monophosphate. On the other hand, melanoma cell adhesion molecule promoter activity was impeded upon treatment with phorbol esters or in the presence of stem cell factor, a phenomenon which was protein kinase C-dependent. Promoter-deletion studies demonstrated that the first 196 nt of the melanoma cell adhesion molecule promoter region are sufficient to get full expression in metastatic melanoma cells. This fragment contains five binding sites for the transcription factor Sp1 and DNA mobility shift experiments showed direct binding of Sp1 to the promoter. In conclusion, our results indicate that Sp1 is sufficient to drive constitutive melanoma cell adhesion molecule expression in metastatic melanoma cells. In nonmetastatic cells, however, melanoma cell adhesion molecule expression is repressed and we speculate that stem cell factor/c-Kit signaling might be responsible for the control of melanoma cell adhesion molecule synthesis, and thus, perhaps, of melanoma progression and metastasis.
...
PMID:Regulation of the melanoma cell adhesion molecule gene in melanoma: modulation of mRNA synthesis by cyclic adenosine monophosphate, phorbol ester, and stem cell fFactor/c-kKit signaling. 1057 24

We previously demonstrated that expression of the cell surface adhesion molecule MCAM/MUC18 correlates directly with the metastatic potential of human melanoma cells. In addition, the progression of human melanoma towards the metastatic phenotype is associated with loss of expression of the tyrosine-kinase receptor c-KIT. This review summarizes our recent data demonstrating that the expression of both genes is regulated by the AP-2 transcription factor. Moreover, we have observed a loss of AP-2 expression in metastatic melanoma cells. Re-expression of AP-2 in the highly metastatic A375SM cells decreased their tumorigenicity and inhibited their metastatic potential in nude mice. MCAM/MUC18 mRNA and protein expression was significantly downregulated while c-KIT expression was upregulated in the AP-2 transfected cells. Since AP-2 also regulates other genes that are involved in the progression of human melanoma such as E-cadherin, MMP-2, p21WAF-1, HER-2, BCL-2, and insulin like growth factor receptor-1, we propose that loss of AP-2 is a crucial event in the development of malignant melanoma.
...
PMID:Role of AP-2 in tumor growth and metastasis of human melanoma. 1072 91

Conflicting results were obtained by various research groups using the tyrosinase reverse transcription polymerase chain reaction (RT-PCR) for detecting melanoma cells circulating in peripheral blood. Whereas 100% positivity was initially reported for stage IV patients, more recent investigations reported positive detection rates between 30% and 50% in patients with disseminated melanoma. While the high detection rate initially reported in metastatic melanoma may be explained by contamination problems, methodological differences in different steps of the technical procedure of RT-PCR may account for the differences reported in more recent examinations. Major differences may result from the kind of blood preparation, the RNA isolation method, the kind of RT enzyme used, and the gene targeted by PCR primers. In our experience, blood purification by a Ficoll gradient increased melanoma cell detection rates compared to RNA extraction from total blood or after erythrocyte lysis. Amplification of MelanA in addition to tyrosinase resulted in a 30% enhanced sensitivity of melanoma cell detection compared to amplification to tyrosinase alone, whereas gp100/pMel17 and MUC18 gene products were already detected in blood from nonmelanoma patients. These findings are in agreement with those of other groups. Currently, an increase in the sensitivity for detection of circulating tumour cells to more than 50% of patients with disseminated melanoma seems to be unlikely. It is interesting that between 15% and 30% positive results and sometimes more have already been obtained from patients with primary melanoma. So far, there is no data for judging the prognostic significance of the detection of circulating tumour cells in patients without clinically recognisable metastases. Our limited experience shows that staging examinations in these patients reveal no proof of macrometastasis. Therefore, it is presently unclear whether these positive findings are associated with long-term prognosis or if they merely reflect false positive findings in this highly sensitive RT-PCR technique.
...
PMID:Polymerase chain reaction in the detection of circulating tumour cells in peripheral blood of melanoma patients. 1109 36

The cell surface adhesion molecule human MUC18 (huMUC18 or Mel-CAM) has been postulated to play a key pathogenic role in metastatic melanoma progression. To establish an immunocompetent syngeneic mouse model that would greatly facilitate our understanding of the role of MUC18 in the metastatic behavior of melanoma, we cloned and characterized the mouse MUC18 (muMUC18) cDNA gene. The gene was amplified by RT-PCR and RACE of the poly(A)+RNA isolated from the mouse melanoma cell line B16F10/Queens. The cloned muMUC18 cDNA gene contained 28 nucleotides of 5'-UTR, 908 nucleotides of 3'-UTR, and an open reading frame (ORF) of 1947 nucleotides encoding a protein of 648 amino acids, which is two amino acids longer than huMUC18. The size of the muMUC18 mRNA is about 3 kb with a shorter 3'-UTR than the huMUC18 mRNA (about 3.3 kb). Besides, the sequence in the 3' UTR of the two mRNAs is diverse with only 31% identity. The 5'-UTR and coding sequences of the muMUC18 cDNA are 72.4 and 80.6% identical to those of huMUC18, respectively. The deduced amino acid sequence of the muMUC18 cDNA is 76.2% identical to that of huMUC18. The amino acid sequences deduced from MUC18 cDNA sequences from six other mouse melanoma cell lines are identical except one to three residues, suggesting that the muMUC18 cDNA sequence determined in this report is correct. The muMUC18 protein is predicted to be slightly more acidic than the human protein. The levels of muMUC18 mRNA and protein in nine mouse melanoma cell lines were directly proportional to their ability to establish metastatic colonies in lungs of syngeneic mice. Most biological functions of the muMUC18 may be similar to the huMUC18.
...
PMID:Isolation and characterization of mouse MUC18 cDNA gene, and correlation of MUC18 expression in mouse melanoma cell lines with metastatic ability. 1125 16

The molecular changes associated with the transition of melanoma cells from radial growth phase (RGP) to vertical growth phase [(VGP), metastatic phenotype] are not very well defined. We previously demonstrated that expression of the cell-surface adhesion molecule MCAM/MUC18 correlates directly with the metastatic potential of human melanoma cells. In addition, the progression of human melanoma towards the metastatic phenotype is associated with loss of expression of the tyrosine-kinase receptor c-KIT. In this review, I will summarize our recent studies demonstrating that the expression of both genes is regulated by the AP-2 transcription factor. Moreover, we have observed a loss of AP-2 expression in metastatic melanoma cells. Re-expression of AP-2 in the highly metastatic A375SM cells decreased their tumorigenicity and inhibited their metastatic potential in nude mice. MCAM/MUC18 mRNA and protein expression was significantly down-regulated while c-KIT expression was up-regulated in the AP-2-transfected cells. To further investigate the role of AP-2 in the progression of human melanoma, we attempted to inactivate AP-2 in primary cutaneous melanoma by using a dominant-negative AP-2, or the AP-2B gene. Expression of AP-2B in SB-2 cells augmented their tumorigenicity in nude mice, and upregulated MMP-2 expression and activity. As AP-2 also regulates other genes that are involved in the progression of human melanoma such as E-cadherin, p21/WAF-1, HER2/neu, Bcl-2, FAS/APO-1, IGF-R-1, VEGF and the thrombin receptor (PAR-1), we therefore propose that loss of AP-2 is a crucial event in the development of malignant melanoma. In addition, the transition of melanoma cells from RGP to VGP is also associated with over-expression of the transcription factors CREB and ATF-1. The notion that the balance between AP-2 and CREB/ATF-1 expression determines the progression of melanoma cells towards the metastatic phenotype will be discussed.
...
PMID:Gene regulation in melanoma progression by the AP-2 transcription factor. 1131 Jul 95

Normal human melanocytes are interspersed singly among keratinocytes along the basement membrane of the epidermis, whereas melanoma cells readily adhere to each other during invasion of the dermis or distant organs. The tumorigenic and metastatic phenotype of melanoma cells often correlates with increased expression of cell-cell and cell-matrix adhesion receptors. Mel-CAM (MCAM, MUC 18, CD146) is a cell-cell adhesion receptor highly expressed by melanoma cells but not normal melanocytes. We show here that inhibition of Mel-CAM expression in metastatic melanoma cells using genetic suppressor elements of Mel-CAM cDNA leads to inhibition of adhesion between melanoma cells and to downregulation of the tumorigenic phenotype. Growth was not inhibited in genetic suppressor elements-transduced melanoma cells cultured in monolayers but was inhibited when cells were maintained anchorage-independently in soft agar and greatly reduced in immunodeficient mice. A three-dimensional epidermal skin equivalent model demonstrated that Mel-CAM allows melanoma cells to separate from the epidermis and invade the basement membrane zone and dermis. However, melanoma cells with little or no Mel-CAM were poorly invasive, possibly due to their loss of gap junctional communication. These results suggest the multifunctional role of a melanoma-associated cell-cell adhesion receptor in tumor progression.
...
PMID:Mel-CAM-specific genetic suppressor elements inhibit melanoma growth and invasion through loss of gap junctional communication. 1149 90

Activating transcription factor-1 (ATF-1) and cAMP-responsive element (CRE)-binding protein (CREB) have been implicated in cAMP and Ca2+-induced transcriptional activation. The expression of the transcription factors ATF-1 and CREB is upregulated in metastatic melanoma cells. However, how overexpression of ATF-1/CREB contributes to the acquisition of the metastatic phenotype is unclear. Previously we demonstrated that quenching of CREB activity in metastatic melanoma cells by means of a dominant-negative form of CREB (KCREB) led to a decrease in their tumorigenicity and metastatic potential in nude mice. We identified two mechanisms that explain how overexpression of CREB/ATF-1 contributes to the metastatic phenotype. The first is one in which CREB/ATF-1 play an essential role in invasion by regulating the CRE-dependent expression of the metalloproteinase MMP-2 and the adhesion molecule MCAM/MUC18 genes. In the second mechanism, CREB and ATF-1 act as survival factors for human melanoma cells. Here, the effect of disrupting ATF-1 activity was investigated using intracellular expression of an inhibitory anti-ATF-1 single chain antibody fragment (ScFv). Intracellular expression of ScFv anti-ATF-1 in MeWo melanoma cells caused significant reduction in CRE-dependent promoter activation. In addition, expression of ScFv anti-ATF-1 in melanoma cells suppressed their tumorigenicity and metastatic potential in nude mice. ScFv anti-ATF-1 rendered the melanoma cells susceptible to thapsigargin-induced apoptosis in vitro and caused massive apoptosis in tumors transplanted subcutaneously into nude mice, confirming that AFT-1/CREB act as survival factors for human melanoma cells. These studies demonstrate the potential usage of ScFv anti-ATF-1 as an inhibitor of tumor growth and metastasis of solid tumors in vivo.
...
PMID:Targeting the ATF-1/CREB transcription factors by single chain Fv fragment in human melanoma: potential modality for cancer therapy. 1164 9


1 2 3 Next >>

---