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:C0677930 (
primary tumor
)
20,210
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
It is now clear that adhesive interactions play a critical role in the process of metastatic tumor dissemination. Adhesion molecules act as both positive and negative modulators of the metastatic process. Molecules such as E-cadherin that promote homotypic tumor cell adhesion function to maintain intercellular contacts that confine cells to the
primary tumor
site and are negatively correlated with metastatic potential. Because tumor cells are rapidly eliminated from the circulation, those cells that can quickly arrest in the vasculature at a secondary site and pass through the vessel wall into the surrounding tissue will have a selective advantage toward establishing new metastatic colonies. The first step in this process is specific adhesion to venular endothelial cells in selected organs, a process mediated by tumor cell surface molecules such as Sialyl LewisX or the VLA-4 (alpha 4 beta 1) integrin that mediate binding to endothelial adhesion molecules such as the
E-selectin
or the vascular cell adhesion molecule, VCAM-1. Site-specific endothelial determinants such as the lung endothelial cell adhesion molecule, LuECAM, may additionally specify particular sites for preferential adhesion and subsequent site-specific metastasis of particular tumor types. After adherence to endothelial cells and subsequent endothelial retraction, metastatic tumor cells must adhere to elements of the subendothelial basement membrane such as laminin and types IV and V collagen, interactions frequently mediated by members of the beta 1 and beta 4 integrin families. Finally, metastatic tumor cell adhesion to connective tissue elements such as fibronectin, type I collagen and hyaluronan, mediated by molecules such as the beta 1 integrins and by the CD44 cell surface adhesion molecule, are required for movement of tumor cells into the subendothelial stroma and subsequent growth at these new sites. Thus, metastatic potential can be influenced both positively and negatively by a variety of cell surface adhesive molecules that act both independently and in concert to direct tumor cells to particular tissues, allowing them to arrest in those tissues, migrate across the vessel wall and grow at the secondary site. In the current review, I discuss the nature of the adhesion molecules that have been implicated in the metastatic process, emphasizing those molecules that have been shown to correlate with metastasis in clinical human tumors or that have been shown to influence metastatic potential in in vivo experimental assays.
...
PMID:Adhesion molecules in tumor metastasis. 840 Jan 43
Aberrant glycosylation expressed in glycosphingolipids and glycoproteins in tumor cells has been implicated as an essential mechanism in defining stage, direction, and fate of tumor progression. This general concept is supported by results from three lines of study: (a) Numerous clinicopathological studies have shown a clear correlation between aberrant glycosylation status of
primary tumor
and invasive/metastatic potential of human cancer as reflected by 5- or 10-year survival rates of patients. (b) Carbohydrates expressed in tumor cells are either adhesion molecules per se or modulate adhesion receptor function. Some are directly involved in cell adhesion. They are recognized by selectins or other carbohydrate-binding proteins or by complementary carbohydrates (through carbohydrate-carbohydrate interaction). N- or O-glycosylation of functionally important membrane components may alter tumor cell adhesion or motility in a direction that either promotes or inhibits invasion and metastasis. Examples of such receptors are E-cadherin, integrins, immunoglobulin family receptors (e.g., CD44), and lysosome-associated membrane protein. (c) Gangliosides and sphingolipids modulate transmembrane signaling essential for tumor cell growth, invasion, and metastasis. The transducer molecules susceptible to gangliosides and sphingolipids include integrin receptors, tyrosine kinase-linked growth factor receptors, protein kinase C, and G-protein-linked receptor affecting protein kinase A. Some glycosphingolipids (e.g., Gb3Cer, Le(y), ceramide, and sphingosine induce tumor cell differentiation and subsequent apoptosis. Shedded gangliosides may block immunogenicity of tumor cells, providing conditions favorable for "escape" from immunological suppression of tumor growth by the host. Various reagents that block carbohydrate-mediated tumor cell adhesion or block glycosylation processing have been shown to inhibit tumor cell metastasis. This provides the basis for further development of "anti-adhesion therapy." Ganglioside analogues and sphingolipid analogues that inhibit protein kinase C and receptor-associated tyrosine kinase have been applied for inhibition of metastasis. A crucial mechanism for inhibition of metastasis by these reagents may involve blocking of transmembrane signaling for expression of P- and
E-selectin
. This provides the basis for development of "ortho-signaling therapy."
...
PMID:Tumor malignancy defined by aberrant glycosylation and sphingo(glyco)lipid metabolism. 896 75
Angiogenesis has an important role in the progression of solid tumors. Therefore, we measured the blood levels (ELISA) of angiogenic factors [basic fibroblast growth factor (bFGF), hepatocyte growth factor/scatter factor, and vascular endothelial growth factor (VEGF)] and soluble adhesion molecules [
E-selectin
, intercellular adhesion molecule (ICAM-1), platelet endothelial cell adhesion molecule-1, and vascular cell adhesion molecule-1] in 76 consecutive patients with untreated renal cell carcinoma and 41 healthy controls to evaluate their prognostic value. The serum levels of bFGF, hepatocyte growth factor, and VEGF were significantly higher in patients with renal cancer than they were in healthy subjects. bFGF and VEGF values were significantly higher in patients with disseminated cancer (N+ and/or M+) than they were in those with undisseminated (M-N-) cancer: median = 27 pg/ml, range = 5-118, n = 15 versus median = 8 pg/ml, range = 1-149, n = 61 (P = 10(-4)) for bFGF; and median = 883 pg/ml, range = 200-2317, n = 15 versus median = 278 pg/ml, range = 0-1704, n = 61 (P = 0.006) for VEGF. The blood levels of ICAM-1 and vascular cell adhesion molecule-1 were significantly higher, and the levels of
E-selectin
and platelet endothelial cell adhesion molecule-1 were significantly lower in patients with renal cancer than they were in controls. Plasma ICAM-1 was higher in metastatic patients (M+) than they were in nonmetastatic (M-) patients: median = 687 ng/ml, range = 294-1091, n = 12 versus median = 408 ng/ml, range = 217-1375, n = 64 (P = 10(-4)). ICAM-1 and bFGF blood values were correlated with the size of the
primary tumor
. The interleukin 6 and tumor necrosis factor-alpha (TNF-alpha) values of these patients have been previously published and are included in the survival analysis. Univariate analysis showed that bFGF, ICAM-1, interleukin 6, and TNF-alpha, before treatment, were prognostic factors. In multivariate analysis for proportional hazard regression, only TNF-alpha was an independent prognostic indicator, with a normal plasma TNF-alpha being highly predictive for a good prognosis in patients with untreated renal cell carcinoma.
...
PMID:Are angiogenic factors, cytokines, and soluble adhesion molecules prognostic factors in patients with renal cell carcinoma? 981 46
Several lines of evidence indicate that sialosyl Le(a), tumor-associated carbohydrate antigen present on human colon carcinoma cells, is involved in formation of metastases. To study the role of this carbohydrate structure in development of metastases, we have used the clone of human colon carcinoma CX-1 cells transfected with antisense expression vector containing fragment of cDNA for alpha1,3/4-fucosyltransferase (FT III), which is involved in synthesis of sialosyl Le(a) tetrasaccharide. It has been reported previously that, in contrast to the parental cells, the antisense-transfected CX-1.1AS5 cells do not express sialosyl Le(a) and do not adhere to
E-selectin
-expressing CHO cells. In the present work we have studied the formation of liver metastases by CX-1.1AS5 cells after their orthotopic or intrasplenic implantation into athymic nu/nu mice. After orthotopic implantation of sialosyl Le(a)-negative colon carcinoma CX-1.1AS5 cells, the number of mice with liver metastases was markedly lower (21% of mice) in comparison with their number after implantation of the parental CX-1.1 cells (86% of mice). However, no differences in ability to form colonies in liver were observed between parental CX-1.1 cells and antisense-transfected CX-1.1AS5 cells after intrasplenic inoculation. The liver metastases were formed in 89% and 84% of mice, respectively. Our data support the thesis on the importance of sialosyl Le(a) antigen expression in the development of liver metastases by colon cancer cells, and indicate the role of transplantation route and
primary tumor
localization in formation of metastases.
...
PMID:Metastatic potential of human CX-1 colon adenocarcinoma cells is dependent on the expression of sialosyl Le(a) antigen. 1021 80
Inflammatory breast carcinoma (IBC) is characterized by florid tumor emboli within lymphovascular spaces termed lymphovascular invasion (LVI). Using a human-scid model of IBC (MARY-X), we have demonstrated using retrovirally-mediated dominant-negative E-cadherin mutant approaches (H-2K(d)-E-cad), that the tumor cell embolus (IBC spheroid) forms on the basis of an intact and overexpressed E-cadherin/alpha, beta-catenin axis which mediates tumor cell-tumor cell adhesion analogous to the embryonic blastocyst and accounts for the compactness of the embolus. The tumor cell embolus (IBC spheroid), in contrast, fails to bind the surrounding vascular endothelial cells both in vitro and in vivo because of markedly decreased sialyl-Lewis X/A carbohydrate ligand-binding epitopes on its overexpressed MUC1 which are necessary for binding endothelial cell
E-selectin
. This tumor cell-endothelial cell aversion further contributes to the compactness of the IBC spheroid and its passivity in metastasis dissemination. This passivity is manifested by a dramatic increase in metastatic pulmonary emboli following palpation of the
primary tumor
. In assessing this passivity of metastatic dissemination, we compared the effects of palpation on MARY-X with the effects of palpation on a derived dominant-negative E-cadherin mutant (H-2K(d)-E-cad), as well as other well known human tumoral xenografts exhibiting no (MCF-7, T47D), low (MDA-MB-231, MDA-MB-468) or high (C8161, M24(met)) levels of spontaneous metastasis but no LVI. Palpation of each xenograft similarly increased intratumoral pressure by 200% (10-->30 mmHg) but dramatically increased the numbers and sizes of pulmonary metastases 10-100-fold (P<0.001) only in MARY-X. The mechanism of this effect was through an immediate post-palpation release of circulating tumor emboli detected 2-3 min after palpation (P<0.01) by human cytokeratin 19 RT-PCR of extracted RNA from 300 microl of murine blood. Although circulating human tumor cell-derived growth factors (IGF-I, IGF-II, TGF-alpha and TGF-beta) and angiogenic factors (VEGF and bFGF) were detected by ELISA in murine serum of MARY-X, palpation did not further increase the circulating levels of these factors (P>0.1). Our findings support the cooperative role of E-cadherin and sialyl-Lewis X/A-deficient MUC1 in the passive dissemination of tumor emboli in IBC.
...
PMID:Cooperative role of E-cadherin and sialyl-Lewis X/A-deficient MUC1 in the passive dissemination of tumor emboli in inflammatory breast carcinoma. 1203 65
Adhesion molecules play an important role in tumor metastasis.
E-selectin
can support adhesion of colon cancer cells through the recognition of specific carbohydrate ligands. High levels of soluble
E-selectin
(sE-selectin) had been reported in melanoma and some epithelial tumors, especially in colorectal carcinoma. The concentrations of the sE-selectin were investigated in serum samples of 64 patients (32 men and 32 women) with colorectal cancer and 16 healthy subjects. Median age was 57 (range 20-75). Nineteen patients were staged as Dukes D, 9 of whom had liver metastasis. Serum levels of sE-selectin were determined by ELISA. In the study group, sE-selectin concentrations (mean+/-SE, ng/ml) were not significantly elevated, compared with the control group (41.09+/-4.57 in the control group and 43.80+/-1.88 in patients, p>0.05). Mean sE-selectin levels were 42.27+/-1.85 in non-metastatic and 47.42+/-4.57 in metastatic patients (p>0.05). Serum concentrations of sE-selectin were significantly elevated in patients with colorectal cancer metastatic to liver (59.07+/-7.52) in comparison to other patients without liver metastasis (p=0.013). There were no significant correlations between sE-selectin levels and other parameters such as age of patients, stage of disease, histopathological differentiation or localization of
primary tumor
. Elevated sE-selectin levels were confirmed as correlating with poor overall survival. In conclusion, sE-selectin concentrations may not be used as a predictive marker of metastasis in colorectal carcinoma, but high levels of sE-selectin may support diagnosis of liver metastasis.
...
PMID:Serum levels of soluble E-selectin in colorectal cancer. 1525 58
Increasing evidence indicates that the expression of the endothelial adhesion molecule
E-selectin
is associated with progression and metastasis of breast cancer. Patients with liver metastases also show increased serum levels of the soluble form of
E-selectin
. It was our aim to compare serum levels of soluble
E-selectin
(sES) in such patients with the biology of the
primary tumor
and the course of the metastatic disease under therapy. We examined 69 patients with liver metastases from breast cancer who were selected to receive systemic tumor therapy because of progressive disease (n = 44) or newly detected liver metastases (n = 25). Serum concentrations of sES were measured before each therapy cycle using a specific ELISA. Serum concentrations of sES before the start of therapy were compared to clinical parameters and histopathological findings referring to the
primary tumor
. Secondly, serum levels of sES were compared to serum concentrations of the corresponding tumor markers. We observed a possible trend for certain unfavorable prognostic parameters (e.g., young women, low-graded tumors, human epidermal growth factor receptor 2 overexpression) to be related to higher serum levels of sES. Serum levels of sES were correlated with tumor marker levels in a logarithmical relation (r = 0.44, P < 0.0005). In some cases it could be demonstrated that serum levels of sES changed similarly to the course of tumor marker levels. We conclude that serum levels of sES are associated with the clinical course of liver metastases from breast cancer. Further investigations are needed to clarify if serum levels of sES may serve as tumor marker in certain clinical situations.
E-selectin
should be evaluated as a possible target for antimetastatic therapy studies.
...
PMID:Serum levels of soluble E-selectin are associated with the clinical course of metastatic disease in patients with liver metastases from breast cancer. 1566 1
Expression of sialyl Lewis(x) (sLe(x)) and sLe(a) on tumor cells is thought to facilitate metastasis by promoting cell adhesion to selectins on vascular endothelial cells. Experiments supporting this concept usually bypass the early steps of the metastatic process by employing tumor cells that are injected directly into the blood. We investigated the relative role of sLe(x) oligosaccharide in the dissemination of breast carcinoma, employing a spontaneous murine metastasis model. An sLe(x) deficient subpopulation of the 4T1 mammary carcinoma cell line was produced by negative selection using the sLe(x)-reactive KM93 MAb. This subpopulation was negative for
E-selectin
binding but retained P-selectin binding. Both sLe(x)-negative and -positive cells grew at the same rate; however, sLe(x)-negative cells spread more efficiently on plates and had greater motility in wound-scratch assays. Mice inoculated in the mammary fat pad with sLe(x)-negative and -positive variants produced lung metastases. However, the number of lung metastases was significantly increased in the group inoculated with the sLe(x)-negative variant (p = 0.0031), indicating that negative selection for the sLe(x) epitope resulted in enrichment for a subpopulation of cells with a high metastatic phenotype. Cell variants demonstrated significant differences in cellular morphology and pattern of tumor growth in primary and secondary tumor sites. These results strongly suggest that loss of sLe(x) may facilitate the metastatic process by contributing to escape from the
primary tumor
mass.
...
PMID:Deficiency in surface expression of E-selectin ligand promotes lung colonization in a mouse model of breast cancer. 1590 60
Radiotherapy (RT) plays a key role in cancer treatment. Although the benefit of ionizing radiation (IR) is well established, some findings raise the possibility that irradiation of the
primary tumor
not only triggers a killing response but also increases the metastatic potential of surviving tumor cells. Here we addressed the question of whether irradiation of normal cells outside of the
primary tumor
augments metastasis by stimulating the extravasation of circulating tumor cells. We show that IR exposure of human endothelial cells (EC), tumor cells (TC) or both increases TC-EC adhesion in vitro. IR-stimulated TC-EC adhesion was blocked by the HMG-CoA reductase inhibitor lovastatin. Glycyrrhizic acid from liquorice root, which acts as a Sialyl-Lewis X mimetic drug, and the Rac1 inhibitor NSC23766 also reduced TC-EC adhesion. To examine the in vivo relevance of these findings, tumorigenic cells were injected into the tail vein of immunodeficient mice followed by total body irradiation (TBI). The data obtained show that TBI dramatically enhances tumor cell extravasation and lung metastasis. This pro-metastatic radiation effect was blocked by pre-treating mice with lovastatin, glycyrrhizic acid or NSC23766. TBI of mice prior to tumor cell transplantation also stimulated metastasis, which was again blocked by lovastatin. The data point to a pro-metastatic trans-effect of RT, which likely rests on the endothelial radiation response promoting the extravasation of circulating tumor cells. Administration of the widely used lipid-lowering drug lovastatin prior to irradiation counteracts this process, likely by suppressing Rac1-regulated
E-selectin
expression following irradiation. The data support the concern that radiation exposure might increase the extravasation of circulating tumor cells and recommend co-administration of lipid-lowering drugs to avoid this adverse effect of ionizing radiation.
...
PMID:Rac1-regulated endothelial radiation response stimulates extravasation and metastasis that can be blocked by HMG-CoA reductase inhibitors. 2203 82
Circulating tumor cells (CTC) are cells that disseminate from a
primary tumor
throughout the circulatory system and that can ultimately form secondary tumors at distant sites. CTC count can be used to follow disease progression based on the correlation between CTC concentration in blood and disease severity. As a treatment tool, CTC could be studied in the laboratory to develop personalized therapies. To this end, CTC isolation must cause no cellular damage, and contamination by other cell types, particularly leukocytes, must be avoided as much as possible. Many of the current techniques, including the sole FDA-approved device for CTC enumeration, destroy CTC as part of the isolation process (for more information see Ref. 2). A microfluidic device to capture viable CTC is described, consisting of a surface functionalized with
E-selectin
glycoprotein in addition to antibodies against epithelial markers. To enhance device performance a nanoparticle coating was applied consisting of halloysite nanotubes, an aluminosilicate nanoparticle harvested from clay. The
E-selectin
molecules provide a means to capture fast moving CTC that are pumped through the device, lending an advantage over alternative microfluidic devices wherein longer processing times are necessary to provide target cells with sufficient time to interact with a surface. The antibodies to epithelial targets provide CTC-specificity to the device, as well as provide a readily adjustable parameter to tune isolation. Finally, the halloysite nanotube coating allows significantly enhanced isolation compared to other techniques by helping to capture fast moving cells, providing increased surface area for protein adsorption, and repelling contaminating leukocytes. This device is produced by a straightforward technique using off-the-shelf materials, and has been successfully used to capture cancer cells from the blood of metastatic cancer patients. Captured cells are maintained for up to 15 days in culture following isolation, and these samples typically consist of >50% viable primary cancer cells from each patient. This device has been used to capture viable CTC from both diluted whole blood and buffy coat samples. Ultimately, we present a technique with functionality in a clinical setting to develop personalized cancer therapies.
...
PMID:Rapid isolation of viable circulating tumor cells from patient blood samples. 2273 59
1
2
Next >>