UMLS:C0178874 - FACTA Search

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

The cell-surface heterodimers of the integrin family of molecules, which mediate cell-cell and cell-substratum interactions, are likely to be functionally relevant in local and metastatic tumor growth. In the present study we have analyzed whether the alpha 3/beta 1 receptor for collagen, laminin and fibronectin undergoes changes in expression during tumor progression in cutaneous malignant melanoma (CMM). The results of this study have demonstrated that, while low levels of VLA3 expression are detectable in benign lesions, in primary melanomas the heterodimer undergoes progressive increase in expression which correlates with the degree of dermal invasiveness. Metastatic lesions were found VLA3 positive in 82% of cases. Furthermore, the heterodimer is homogeneously expressed in multiple autologous metastases. The presence of VLA3 correlates with detection of at least one of the ligands in 45% of the cases studied. These findings provide additional evidence that tumor progression in CMM is associated with changes in integrin phenotypes which include the alpha 3/beta 1 heterodimer.
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PMID:Integrin expression in cutaneous malignant melanoma: association of the alpha 3/beta 1 heterodimer with tumor progression. 847 49

Carcinogenesis requires a complex series of genetic changes often involving multiple oncogenes and the inactivation of multiple tumor-suppressor genes. We presently examined the effect of the Krev-1 tumor-suppressor gene on the tumorigenic and metastatic potential of Ha-ras-transformed cloned rat embryo fibroblast (CREF) cells. Ha-ras-transformed CREF cells are morphologically transformed and anchorage independent; produce reduced levels of nm23-H1 (a putative metastasis-suppressor gene product) and TIMP-1 (tissue inhibitor of metalloproteinase 1) transcripts and mRNA compared with CREF cells; produce increased levels of cripto, 94-kDa gelatinase/type IV collagenase (94-kDa GEL), osteopontin (OPN) and transin/stromelysin transcripts and mRNA compared with CREF cells; and are tumorigenic and metastatic in both nude mice and syngeneic rats. Ha-ras-transformed CREF cells coexpressing the Krev-1 gene display a reversion in cellular phenotype and gene expression to that of untransformed CREF cells. However, Ha-ras/Krev-1-coexpressing CREF cells retain, albeit with extended latency periods, both tumorigenic and metastatic potential that is not related directly to the final level of Ha-ras or Krev-1 mRNA or the Ha-ras p21 transforming protein. Development of metastatic potential is, however, directly correlated with a reduction in nm23-H1 and TIMP-1 transcription and mRNA levels and an enhanced expression of cripto, 94-kDa GEL, osteopontin and transin. In contrast, expression of additional tumor-suppressor genes, such as the RB gene and p53, or genes associated with tumorigenesis in other model systems, such as major excreted glycoprotein (MEP), 72-kDa gelatinase/type IV collagenase (72-kDa GEL), fibronectin (FIB), tenascin and intracellular adhesion molecule 1 (ICAM-1) is not altered in a consistent manner during in vitro transformation suppression or escape from tumorigenic and metastatic suppression. These results indicate that Krev-1 suppression of the Ha-ras-transformed/oncogenic phenotype is associated with a distinct program of gene expression changes manifested by altered rates of transcription and steady-state mRNA levels of specific oncogenic-suppressing and oncogenic-inducing genes. These data support a model of Ha-ras-induced metastasis in CREF cells that involves a direct modulation in the expression/suppression of specific combinations of oncogenic-suppressor genes and metastasis-promoting genes that are regulated coordinately in the process of tumor progression.
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PMID:Defining the critical gene expression changes associated with expression and suppression of the tumorigenic and metastatic phenotype in Ha-ras-transformed cloned rat embryo fibroblast cells. 847 44

Cell adhesion receptors (eg, integrins and CD44) play an important role in invasion and metastasis during tumor progression. The increase in integrin alpha 4 beta 1 expression on primary melanomas has been reported to significantly correlate with the development of metastases. alpha 4 beta 1 is a cell surface heterodimer that mediates cell-cell and cell-extracellular matrix interactions through adhesion to vascular cell adhesion molecule (VCAM)-1 and to the IIICS region of fibronectin. To test the effects of alpha 4 beta 1 expression on tumor cell metastasis, Chinese hamster ovary cells were transfected with human alpha 4 cDNA. Whereas alpha 4-negative Chinese hamster ovary cells developed only pulmonary metastasis, alpha 4-positive Chinese hamster ovary cells developed bone and pulmonary metastasis in 3 to 4 weeks when injected intravenously into nude mice. Bone metastasis was inhibited by antibody against alpha 4 or VCAM-1. Expression of alpha 3 beta 1, alpha 6 beta 1, or alpha V beta 1 did not induce bone metastasis. Expression of alpha 4 beta 1 also induced bone metastasis in K562 human erythroleukemia cells injected into SCID mice. These results demonstrate that alpha 4 beta 1 can induce tumor cell trafficking to bone, probably via interaction with VCAM-1 that is constitutively expressed on bone marrow stromal cells.
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PMID:Induction of experimental bone metastasis in mice by transfection of integrin alpha 4 beta 1 into tumor cells. 854 26

We studied the adhesive characteristics of melanocytes, cultured either in the presence of the mitogen phorbol 12-myristate 13-acetate (PMA) that keeps them in a proliferative state, or in the absence of PMA allowing them to differentiate. On proliferating melanocytes, several integrins, ICAM-1, E-cadherin, and CD44 were expressed. In the absence of PMA, proliferation was arrested, melanin synthesis increased, and the morphology of the melanocytes became more spreaded. Under these conditions, expression of integrins alpha 3 beta 1 and alpha 5 beta 1 decreased, whereas expression of alpha 2 beta 1, alpha 4 beta 1, and alpha 6 beta 1 increased. No changes were observed for any of the other adhesion molecules. Immunoprecipitations from metabolically labeled cells confirmed the shift in integrin expression at the level of biosynthesis. The increased surface expression of alpha 2 beta 1 and alpha 6 beta 1 in the absence of PMA was accompanied by an induction of adhesion to basement membrane components collagen and laminin through these integrins. Integrin alpha 5 beta 1/alpha v beta 3-mediated adhesion to fibronectin, CD44-mediated adhesion to hyaluronate, and E-cadherin/beta 1-integrin-mediated adhesion to keratinocytes were not affected by PMA. These findings indicate that by selective modulation of the expression of adhesion molecules, adhesion to components of the basement membrane is reduced in proliferating melanocytes, whereas adhesion to keratinocytes is maintained. Similar events may be involved in melanocyte proliferation and migration during wound healing and initial steps of melanocytic tumor progression.
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PMID:Loss of adhesion to basement membrane components but not to keratinocytes in proliferating melanocytes. 873 21

CD63 belongs to the transmembrane 4 superfamily of membrane proteins and is expressed in several normal tissues as well as in melanoma cells. Previous reports have suggested that CD63 may play an important role in inhibiting melanoma progression, and this was supported by our studies showing that CD63 was associated with suppression of the growth of melanoma in nude mice. Recently, we and others have shown that CD63 may form noncovalent associations with beta1 integrins, which suggests that the function of CD63 may be related to that of integrins. To further explore the role of CD63 in melanoma, we transfected CD63 into a highly motile, CD63-negative melanoma cell line, KM3, which was shown to express alpha(v)beta5 as the predominant integrin with only trace amounts of beta1 integrins. Following transfection, CD63 was shown to associate with beta1 integrins, and beta1 expression appeared to be up-regulated. Cell motility in serum-containing media was markedly suppressed following transfection of CD63. This inhibition was potentiated by mAbs to CD63, and correlated with the level of CD63 expression. The CD63-transfected, but not the untransfected, melanoma cells showed increased adhesion and migration on the beta1 substrates, fibronectin, laminin, and collagen, whereas rates of migration were similar on the beta5 substrate, vitronectin. These results show that CD63 is involved in regulation of the motility of melanoma cells and their adhesion and migration on substrates associated with beta1 integrins. We suggest they provide further insights into the role of CD63 in tumor progression.
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PMID:Regulation of tumor cell motility and migration by CD63 in a human melanoma cell line. 912 Feb 93

Development and progression of prostate cancer is a multistep process of cumulative genetic damage, acquired during a life-time. However, the altered genotype acts against an appropriate background of epigenetic control mechanisms. Several mechanisms of mitotically heritable, epigenetic control of differential gene transcription have been noted, such as stromal-epithelial and cell-cell interactions. In prostate cancer, an important, supporting and/or inhibiting role of stromal-epithelial interaction has been implicated in tumor growth, angiogenesis and metastasis, which includes cell proliferation, adhesion and motility. Within these processes, data mainly obtained in systems other than the prostate have shown a crucial (regulatory) role of proteoglycans (PGs) acting at the level of cell-cell and cell-pericellular matrix interactions. Although little information has been recorded from normal, benign hyperplastic and malignant prostate tissue, PGs are components of both the cell surface and the extracellular matrix (ECM) that form associations with other molecules, such as fibronectin and laminin. On the basis of cell-ECM adhesion/interaction as a prerequisite for both cell proliferation and motility, and the involvement of PGs, the purpose of this study was to investigate the possible biological relevance of (free) glycosaminoglycans (GAGs), as major functional substructures of PGs, on cell adhesion of a series of human prostatic cell lines cultured in vitro. The effects of a series of exogenously applied GAGs on cell adhesion and proliferation were studied in the human cell lines LNCaP, DU 145 and PC-3, cultured on tissue culture plastic as substratum. The applied GAGs were the natural GAGs heparin, heparan, dermatan, chondroitin-4 and chondroitin-6 sulfate, and the semisynthetic, GAG-like pentosan polysulfate (PPS). Addition of GAGs (1-300 micrograms/ml) to cultures that were allowed to adhere for 24 h prior to GAG addition did not affect cell proliferation. In contrast, whereas the natural GAG added during cell adhesion had no effect. PPS strongly inhibited proliferation of LNCaP and DU145, but not the less anchorage-dependent PC-3 cells. Under the latter conditions, after 6 days of culturing the IC50 of proliferation were determined to be < 1 and 50 micrograms PPS/ml for LNCaP and DU145, respectively, corresponding with a profound effect on cell morphology. Direct measurements of cell adhesion confirmed that, in contrast to the natural GAGs, PPS inhibited cell adhesion. In conclusion, the interference of a nonnatural, GAG-like structure with cell adhesion may be interpreted as the involvement of PGs of the cell surface in cell adhesion, possibly affecting the various processes (proliferation, angiogenesis and metastasis) of prostate tumor progression. Although similar interferences of nonnatural GAGs with cell-adhesion-associated proliferation of anchorage-dependent cells remain to be established under in vivo conditions, this type of compounds deserves further attention as a tool with which to study the role of cell adhesion in the progression of prostate cancer and as a potential candidate for the development of a stromal-epithelial targeted therapy.
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PMID:Role of proteoglycans in cell adhesion of prostate cancer cells: from review to experiment. 914 93

The integrin alphaIIb beta3 is a membrane receptor which was considered to be expressed only in cells of megakaryocytic lineage. We have shown that alphaIIb beta3 is expressed in mouse melanoma B16a cells, and in human prostate adenocarcinoma cells. The purpose of this study was to determine whether the megakaryocytic product alphaIIb beta3 was functionally expressed in other non-megakaryocyte lineage tumor cells. By using the reverse transcription polymerase chain reaction (RT-PCR), we have obtained data demonstrating that alphaIIb beta3 is expressed in a variety of tumor cell lines (17) derived from different species (human, rat and mouse) and of different histological origins (skin, blood, lung, liver, kidney, cervix, colon, bladder, breast and prostate). Immunostaining of tumor cells with a monoclonal antibody (MAb) to alphaIIb beta3 demonstrates that alphaIIb beta3 protein is also expressed in tumor cells. A protein kinase C activator PMA stimulates adhesion of tumor cells to fibronectin and fibrinogen, and this stimulated adhesion is blocked by a function-blocking MAb directed to alphaIIb beta3. Our results indicate that the megakaryocytic gene product alphaIIb beta3 integrin is widely expressed among tumor cells of non-megakaryocytic lineage, suggesting that ectopic expression of this integrin may play an important role in tumor progression.
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PMID:Ectopic expression of platelet integrin alphaIIb beta3 in tumor cells from various species and histological origin. 925 5

To understand the mechanisms of tissue remodeling during cancer progression, it is important to know the type of cells that actively express extracellular matrix (ECM) proteins. Twenty-nine adenocarcinomas, 5 adenomas and non-neoplastic mucosa samples were therefore investigated to determine their fibronectin (FN) and tenascin-C (TN-C) expression using in situ hybridization (ISH) and immunohistochemical staining. In the non-neoplastic mucosa, no mRNA signals were found. Two of the adenomas demonstrated positive signals in peri-cryptal cells and the vessels. In the cancers, TN-C and FN mRNAs were found in 86% and 96% of the total cases, respectively. The signals were mainly detected in myofibroblasts, labeled with alpha-smooth muscle actin, in the cancer stroma. TN-C mRNA-positive cells were often observed in localized areas, such as in cancer stroma associated with invading edges and/or in host tissues surrounding the invading cancer front, but rarely in the center of the tumors. FN mRNA-positive cells were more widely spread throughout the cancer stroma, although they were also frequently observed at invading edges. Vascular cells in cancer tissues were also labeled. In 10 specimens, cancer cells themselves expressed FN and/or TN-C mRNA. Comparison with histo-pathological findings revealed positive relationships between the degree of mRNA expression of FN and TN-C and the depth of invasion as well as the frequency of metastasis to lymph nodes. The expression of FN and TN-C by myofibroblasts, vascular cells and cancer cells could be important for the remodeling process of neoplastic tissues during cancer development and progression.
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PMID:Expression of fibronectin and tenascin-C mRNA by myofibroblasts, vascular cells and epithelial cells in human colon adenomas and carcinomas. 933 2

The role of transforming growth factor (TGF)-beta type II receptor (T beta RII) in TGF-beta resistance and tumor progression is now well recognized. To test the effects of T beta RII loss in determining malignancy, we transfected a T beta RII-expressing, TGF-beta-sensitive, MCF-7 cell strain (ME24) with a tetracycline-repressible truncated T beta RII (kdT beta RII) construct lacking the cytoplasmic domain of the receptor. Transfection of kdT beta RII into parental ME24 cells (designated ME24t6 after transfection) resulted in high expression levels of kdT beta RII mRNA and cell surface protein which were reversible by tetracycline treatment. ME24t6 cells did not respond to exogenous TGF-beta 1 as measured by inhibition of proliferation or fibronectin (FN) induction, indicating that the truncated T beta RII acted as a dominant-negative inhibitor of both the growth inhibitory and extracellular matrix (ECM) stimulatory TGF-beta effects. Furthermore, inhibition of kdT beta RII expression by tetracycline treatment led to TGF-beta 1-mediated cell growth arrest in the G1 phase of cell cycle and to the accumulation of the hypophosphorylated form of retinoblastoma (Rb) protein. However, compared to parental ME24 cells, transfectants failed to show increased tumorigenicity, indicating that loss of T beta RII itself is not sufficient to account for differences in the malignant properties of T beta RII-expressing and non-expressing MCF-7 cell strains.
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PMID:A kinase-defective transforming growth factor-beta receptor type II is a dominant-negative regulator for human breast carcinoma MCF-7 cells. 945 91

Published data show that reduction or loss of fibronectin or its receptor, alpha5beta1 integrin, occurs frequently in tumors and transformed cells. Furthermore, restoration of these adhesion proteins has been reported to reduce tumorigenesis. These results suggest that fibronectin/alpha5beta1 interactions may act to suppress tumor development or progression. To test this hypothesis in the context of spontaneous tumor formation, we have analyzed tumor development in mice genetically altered in the genes for fibronectin or alpha5 integrin. Our results show that heterozygosity for either does not lead to an increased incidence of tumors, alteration in tumor spectrum, or increased levels of metastasis, even when the fibronectin or alpha5 mutations are combined with mutations in the p53 tumor suppressor gene that lead to spontaneous tumor formation and could also cause loss of heterozygosity. Furthermore, loss of heterozygosity for alpha5 was not a common concomitant of tumorigenesis or metastasis. Finally, chimeric animals containing high proportions of alpha5-null cells did not show an increased incidence of tumors or a change in tumor progression. We conclude that, in the genetic backgrounds studied here, loss of fibronectin or alpha5beta1 integrin does not contribute to tumorigenesis or metastasis.
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PMID:A test of the role of alpha5 integrin/fibronectin interactions in tumorigenesis. 948 45

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