Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

RA 233, a pyrimido-pyrimidine analogue developed originally as an antiplatelet agent, has reduced the incidence of tumor metastases in clinical trials. However, in animal tumor models antimetastatic therapy using RA 233 has been inconsistent. We therefore tested RA 233 for additional effects, such as its direct action on tumor cells. Using the rat 13726NF mammary adenocarcinoma tumor system, low, nontoxic concentrations of RA 233 had pleiotropic and differential effects on two 13762NF tumor cell clones. The growth of MTC cells (low spontaneous metastatic potential) was not affected by low concentrations of RA 233 (50 microM) or epidermal growth factor (EGF) (up to 10 ng/ml) for 3 days in 0.5-10% fetal bovine serum. In contrast, MTLn3 (high spontaneous metastatic potential) cell cultures maintained for 3 days in low (0.5-1%) serum in the presence of 1.25-10 ng/ml EGF doubled in cell numbers compared with control cultures, and addition of 50 microM RA 233 abrogated the growth-stimulatory effect of EGF. The inhibitory effect of RA 233 on MTLn3 cells was dose dependent and not due to cell toxicity as determined by cell viability, cell growth, and colony formation properties after drug removal. In addition, incubation of MTLn3 cells with 50 microM RA 233 resulted in an increase of p21ras protein expression, whereas there was no effect on the level of p21ras in identically treated MTC cells or when either clone was treated with 10 ng/ml EGF. The results suggest that among the heterogeneous effects of RA 233 on tumor cells, modulation of growth factor responses and regulatory molecules may be important.
 ...
PMID:Pyrimido-pyrimidine modulation of EGF growth-promoting activity and p21ras expression in rat mammary adenocarcinoma cells. 305 58

Using the adhesive tumor cell culture system, we studied the effect of epidermal growth factor (EGF) on 16 primary and 7 metastatic fresh human tumors of the nervous system cultured in serum-free and serum-supplemented media at low cell density. In serum-free conditions, EGF significantly enhanced the growth of glial tumor cells. This positive effect was less pronounced for metastases to the brain. No significant enhancement was observed for the other tumor types (primitive neuroectodermal tumors and various tumors of neuroepithelial/mesenchymal origin). The addition of serum obscured this effect of EGF, even at the lowest cell densities. In 7 tumors, the simultaneous addition of platelet-derived growth factor did not enhance the EGF response. Subtypes of brain tumors respond to EGF in vitro under serum-free conditions.
 ...
PMID:Enhancement of growth of primary metastatic fresh human tumors of the nervous system by epidermal growth factor in serum-free short term culture. 326 64

The v-fps oncoprotein was expressed in a pre-neoplastic, growth factor-dependent Chinese hamster lung fibroblast line (CCL39) to study its effect on growth controls and on the induction of malignancy. Two transfectants were characterized which expressed low (39FPS-8) or high (51FPS-6) levels of P130gag-f ps protein-tyrosine kinase activity. 39FPS-8 cells still arrested in quiescence when deprived of growth factors, but developed an increased sensitivity to the mitogenic actions of epidermal growth factor (20-fold) and alpha-thrombin (50-fold), although not to insulin. In contrast, 51FPS-6 cells completely escaped growth controls, divided in serum-free medium, and were insensitive to further growth factor stimulation. Both transfectants produced rapidly growing tumors in nude mice that formed pulmonary metastases from a subcutaneous site, unlike the parental cells which are non-metastatic. 51FPS-6 cells were comparatively more efficient than 39FPS-8 cells in colonizing the lungs after intravenous inoculation. The v-fps tyrosine kinase therefore induces a partial to complete relaxation of growth factor-mediated controls on the CCL39 cell cycle, with the extent of factor independence reflecting the amount of P130gag-f ps synthesized. This reduction in growth factor requirements correlates with the capacity of v-fps to confer the attributes of metastatic tumors upon preneoplastic CCL39 fibroblasts. We speculate that increased sensitivity to growth factor stimulation represents a common mechanism by which tumor cells acquire metastatic properties.
 ...
PMID:v-fps protein-tyrosine kinase coordinately enhances the malignancy and growth factor responsiveness of pre-neoplastic lung fibroblasts. 328 Oct 93

After sc implantation into BALB/c nude mice, factor-dependent and premalignant Chinese hamster lung fibroblasts (CCL39) developed into tumors that occasionally disseminated and produced pulmonary metastases. Unlike CCL39 cells that required several growth factors (insulin, alpha-thrombin, epidermal growth factor) to proliferate in culture, metastatic tumor cells divided autonomously in serum-free medium. The re-implantation of independently isolated primary tumors revealed that they comprised factor-independent clones present at a variable frequency, as well as malignant clones that disseminated to the lungs after sc or iv inoculation. The resulting metastases invariably contained cells that were able to divide in serum-free medium and that presumably represented the progeny of autonomous variants populating the primary tumors. Among ten CCL39 variants selected in vitro for reduced growth factor requirements, two were metastatic upon sc and iv inoculation. These cell lines were the only ones that replicated rapidly in the absence of growth factors. Unlike myc transfectants, CCL39 fibroblasts that were transformed with an activated Harvey ras oncogene or that were infected with polyomavirus were both metastatic and autonomous. Taken together, these observations are consistent with the notion that the metastatic potential of CCL39 tumor cells coincides with their ability to obviate growth factor requirements and thus to divide in an autonomous fashion.
 ...
PMID:Coincidental acquisition of growth autonomy and metastatic potential during the malignant transformation of factor-dependent CCL39 lung fibroblasts. 335 98

The receptor-type oncogenes c-erbB2/neu and c-erbB have been found amplified and/or overexpressed in a number of tumours of epithelial origin. We have studied the expression of oncogenes in biopsies from human thyroid tumours. The c-erbB2/neu and c-erbB oncogenes showed two- to three-fold higher levels of RNA in papillary carcinomas and lymph node metastases as well as in one adenoma when compared to non-tumour tissue. The nuclear oncogenes c-myc and c-fos were found to be expressed at varying levels in both non-tumour and tumour tissue. RNA transcripts specific for the platelet-derived growth factor A and B chains and the N-ras oncogene were detected in one anaplastic carcinoma. Neither rearrangements nor amplifications of oncogenes were observed in the thyroid tumours. These data are particularly interesting in light of the recent findings that epidermal growth factor induces proliferation and dedifferentiation of normal thyroid epithelial cells in vitro. We suggest that the epidermal growth factor or other ligands for the c-erbB and c-erbB2/neu receptors may contribute to the development and/or maintenance of the malignant phenotype of papillary carcinomas of the thyroid.
 ...
PMID:Expression of oncogenes in thyroid tumours: coexpression of c-erbB2/neu and c-erbB. 339 Mar 72

Tissues of normal human gastric mucosae and 15 advanced gastric carcinomas were studied immunohistologically for the presence of receptors for epidermal growth factor (EGF) by use of a murine monoclonal antibody (528IgG), which reacts with the binding domain of human EGF receptor. On normal gastric mucosae, only parietal cells showed positive staining. On cancer tissues, definite staining was observed in 9 of 15 cases. Their staining intensities were variable and weaker in general compared to those of either gastric parietal cells or normal tonsilar squamous epithelium. No apparent correlation of EGF receptor staining with the grade of histologic differentiation or lymph node metastases of these gastric carcinomas was noted.
 ...
PMID:Expression of epidermal growth factor receptors on normal human gastric epithelia and gastric carcinomas. 346 96

125I-EGF binding technique was used to demonstrate high affinity receptor binding for epidermal growth factor (EGF-R) in 72 human mammary carcinomas. 27% of the tumors were EGF-R positive and the presence of this receptor was correlated with receptor levels for estradiol, DNA-pattern, proliferative index, thymidine kinase, tumor size, number of lymph node metastases and 6-year relapse probability. Our results confirm previous reports of an inverse relation between the cellular content of EGF-R and ER. In addition, we could associate EGF-R positivity with an aneuploid DNA-pattern and an increased growth rate, as measured by proliferative index. No correlation was found between EGF-R positivity in the primary tumor and presence of axillary lymph node metastasis at the time of operation. The 6-year relapse rate was somewhat higher for patients whose primary tumors were EGF-R positive. Moreover patients who had lymph node metastases at the time of operation and EGF-R positive tumors experienced a significantly lower 6-year disease free survival rate as compared to those who were node negative and had receptor negative tumors. It remains to be shown whether EGF-R alone can be used as an independent prognostic factor.
 ...
PMID:Prognostic significance of the receptor for epidermal growth factor in human mammary carcinomas. 363 6

Evidence is presented for two different breast epithelial antigens that some epitopes have greater tumor specificity and are more effective targets for radioimmunotherapy than others. The two antigens, which are major components of the human milk fat globule membrane, are breast mucin and a M(r) 46,000 glycoprotein (BA46). Of five monoclonal antibodies (Mc5, Mc1, BrE-1, BrE-2, and BrE-3) against breast mucin, all recognize overlapping amino acid epitopes on the tandem repeat domain. However, each have unique and different tissue and tumor specificities and unique epitope structures on the fully glycosylated breast mucin. In preclinical studies, radioimmunoconjugates of all five monoclonal antibodies inhibit growth of transplantable breast tumors in immunodeficient mice. In human clinical trials, radioiodinated Mc5 was very poor in localizing breast tumor metastases. On the other hand, 111In-labeled BrE-3 imaged almost 90% of breast tumors and showed promise in radioimmunotherapy when labeled with 90Y. The failure of Mc5 in clinical trials may be partly attributed to the high levels of its epitope on circulating mucin compared to the epitope of BrE-3. The Mc5 binding affinity increased significantly with glycosylation, while the BrE-3 epitope was masked by glycosylation. The BA46 glycoprotein is a breast tumor-associated membrane antigen containing an NH2-terminal, epidermal growth factor-like domain into which a cell adhesion sequence (RGD) is inserted and a COOH-terminal domain with homology to the phospholipid binding C1/C2 domain of coagulation factors V and VIII. It promotes cell attachment in an RGD-dependent manner. Monoclonal antibody Mc8, which binds to the C2-like domain, is only moderately effective in experimental radioimmunotherapy, while Mc3, which binds an epitope in the EGF-like RGD domain, was highly effective in destroying breast tumors in nude mice. With 90Y-labeled Mc3, 6 of 7 mice are cured of the tumors. These results indicate that by selecting appropriate monoclonal antibodies, a normal antigen can be used as a target for radioimmunotherapy.
 ...
PMID:Selection of tumor-specific epitopes on target antigens for radioimmunotherapy of breast cancer. 749 58

Determination of the differences between cell lines which are derived from a primary tumour and a disseminated metastatic lesion from the same patient may aid in elucidating the factors associated with disseminated metastases. We report on the establishment and characterisation of two new scirrhous gastric cancer cell lines, designated OCUM-2M and OCUM-2D, derived from a 49-year-old female. OCUM-2M was derived from a primary gastric tumour, and OCUM-2D was derived from a sample of disseminated metastasis. The two cell lines were derived from the same patient. We investigated biological differences between the two cell lines to study mechanisms involved in disseminated metastasis. The growth activity of OCUM-2D cells as determined by doubling time and tumorigenicity was greater than that of OCUM-2M cells. The level of epidermal growth factor receptor (EGFR) expression in OCUM-2D cells was about twice that of OCUM-2M cells and the growth of OCUM-2D cells was stimulated more by epidermal growth factor (EGF) than that of OCUM-2M cells. The invasive activity of OCUM-2D cells was higher than that of OCUM-2M cells and was increased after addition of transforming growth factor-beta 1 (TGF-beta 1). An increase in the number of attached and spreading cells was found following the addition of 10 ng ml-1 TGF-beta 1. These findings suggest that high growth and invasive activity may play an important role in disseminated metastasis and that EGF and TGF-beta 1, which affect the growth and invasive activity of OCUM-2D cells, might be factors associated with metastasis in scirrhous gastric carcinoma. The two cell lines OCUM-2M and OCUM-2D should be beneficial for analysing mechanisms of tumour progression.
 ...
PMID:Establishment of two new scirrhous gastric cancer cell lines: analysis of factors associated with disseminated metastasis. 757 68

An estrogen (E) independent sub-clone (EIIL) was separated from a human endometrial carcinoma cell line, Ishikawa, by culturing the wild type under an E free condition for 350 days. The cells were then implanted into nude mice subcutaneously and tumors allowed to develop for 35 days. The primary lesions were then excised to stimulate recurrence. One animal developed recurrence with multiple distant metastases. The primary tumor and metastatic tumors from the animal were studied for ErbB-2 expression by immunohystochemical techniques or by a reverse transcription followed by polymerase chain reaction (RT-PCR). Expressions of epidermal growth factor (EGF) receptors, aromatase, nidogen, E receptors, hepatocyte growth factors (HGF) and beta-actin were also examined. The results showed that metastatic lesions expressed high levels of ErbB-2, nidogen and aromatase but unchanged levels of EGF receptors and HGF. The metastatic lesions expressed one third of the E receptors which were detected in the EIIL in vitro. These observations suggest that a decrease in ER along with increased expression of nidogen and aromatase is associated with the process of metastasis and the model appears to be of value in studying the process of the acquisition of a metastatic phenotype.
 ...
PMID:[Establishment of metastatic sub-clone from estrogen independent Ishikawa cells and its characterization in vitro and in vivo]. 769 85


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>