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

P-Glycoprotein (Pgp) has been shown to mediate multidrug resistance in tumor cell lines. Overexpression of Pgp has been detected in clinical cancer samples of many histological types. The basis and biological significance of such increases in Pgp expression are not well understood. In this study, the expression of Pgp during stepwise progression to rat liver cancer was examined to investigate the possible role of Pgp in carcinogenesis. An immunohistochemical technique was used to detect Pgp at the single-cell level, in a large number of liver nodules, hepatocellular carcinoma, and in distant metastases of the carcinomas. The results showed that distinct changes in Pgp expression occurred during stepwise liver carcinogenesis and that these changes were closely associated with the microscopic anatomy of the lesions. In contrast to gamma-glutamyl transpeptidase and glutathione S-transferase-7.7, whose expression appeared to correlate with the early steps of liver carcinogenesis, Pgp expression was higher in the large hyperplastic nodules and in hepatocellular carcinomas than in the early microscopic lesions. A particularly striking finding was the consistent expression of Pgp in the lung metastases. These findings suggested that Pgp was associated with a more progressed malignant phenotype in liver carcinogenesis.
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PMID:P-glycoprotein expression during tumor progression in the rat liver. 138 36

The objective of the work reported in this paper was to determine if the tumorigenic response to 1-methyl-1-nitrosourea (MNU) in the mammary gland varied with age of administration and was dose dependent when the carcinogen was injected prior to 50 days of age. Using a recently developed method for mammary tumor induction, MNU was injected i.p. at doses ranging from 25 to 75 mg/kg at 35 days of age or 50 mg/kg at 28, 35 or 42 days of age. Treatment with MNU resulted in induction of both benign and malignant mammary tumors. The incidence of mammary gland adenocarcinomas was 100% at and above the 50 mg/kg dose of MNU, irrespective of the age at which carcinogen was administered. The number of cancers increased in proportion to carcinogen dose, whereas cancer latency decreased as the MNU dose increased. In rats injected with 50 mg MNU/kg body weight at 28, 35 or 42 days of age, differences among groups in cancer incidence, number or latency were not statistically significant. Metastases of mammary neoplasms to lung, liver and spleen were observed in rats injected with MNU at 35 or 42 days of age. These data indicate (i) the dose responsiveness of MNU-induced mammary carcinogenesis in rats initiated prior to 50 days of age; (ii) the lack of effect of age at initiation if prior to 50 days on final tumor outcome; and (iii) that the age at which MNU is injected may affect the metastatic potential of the mammary carcinomas that are induced.
Carcinogenesis 1992 Sep
PMID:Effect of carcinogen dose and age at administration on induction of mammary carcinogenesis by 1-methyl-1-nitrosourea. 139 36

Peptide growth factors are proteins that stimulate cellular proliferation by binding to specific cell membrane receptors. Evidence is accumulating that abnormal regulation of growth factors may contribute to carcinogenesis. The epithelial growth factors, EGF and TGF-alpha, which share the same receptor, EGFR, may play a pivotal role in the development and maintenance of head and neck cancer; preliminary studies concerning TGF-beta and IL-2 are inconclusive. There is increased production of TGF-alpha and EGFR mRNA in the majority of fresh tissues and cell lines from patients with SCCHN. This increase results from transcriptional activation of the gene(s). Therapies directed at the regulation of gene transcription may be useful in chemoprevention or modulation of disease. Nuclear studies that target up-regulated growth factor receptors may improve the ability to detect microscopic regional metastatic disease.
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PMID:The role of peptide growth factors in head and neck carcinoma. 140 94

Clinical trials of drugs that influence coagulation and fibrinolysis pathways have been undertaken in patients with malignancy because these pathways are capable of influencing malignant progression. The validity of this concept was originally confirmed in experimental animal models of malignancy. Earlier pilot studies in human disease have been succeeded by definitive prospective randomized clinical trials that have revealed heterogeneity of responsiveness to anticoagulant and fibrinolytic agents that may be attributable to differences in mechanisms of interaction of the tumor cells of various types of malignancy with these pathways in vivo. In certain tumor types studied thus far, increased tumor response rates and prolongation of survival have been observed that suggest the possibility that substantial benefit may be realized from this treatment approach in patients with malignancy. In addition, the availability of newer and potentially more effective therapeutic agents holds promise for even greater gains in previously tested tumor types. The ability to design treatment regimens that correspond to defined mechanisms that pertain to specific tumor types should permit future studies to be designed rationally. Current data suggest that anticoagulant and fibrinolytic agents might reasonably be tested in tumor types characterized by the existence of a tumor cell-associated coagulation pathway with thrombin generation and conversion of fibrinogen to fibrin (such as small cell carcinoma of the lung). By contrast, protease inhibitors might reasonably be tested in tumor types characterized by expression of tumor cell plasminogen activators. Expansion of current views on the possible role of antithrombic drugs in cancer therapy is justified. For example, antithrombotic drugs classified as non-steroidal anti-inflammatory agents may inhibit carcinogenesis while polyanionic drugs with anticoagulant properties, such as suramin and heparin, may inhibit growth factor interactions with cells. Intriguing new opportunities clearly exist for interactions between clinical and basic investigators that may provide both novel biologic insights and improved patient care.
Cancer Metastasis Rev 1992 Nov
PMID:Clinical trials with anticoagulant and antiplatelet therapies. 142 26

Proto-oncogenes (H-ras-1 and L-myc) and tumor-suppressor gene (p53) loci have been implicated in lung carcinogenesis. DNA restriction fragment length polymorphisms at these gene loci are being evaluated in a case-control study as markers predictive of risk for cancer or of prognosis when cancer is present. The cases and controls had a cigarette-smoking history of 40 or more pack years or other abnormalities in pulmonary function tests, their ages were closely matched (64 years for cases and 61 years for controls) and the ratio of Caucasians to African Americans was close to unity (cases, 0.95:1.00, controls, 1.00:0.88). The H-ras-1 gene contains an insertion deletion polymorphism. Inheritance of rare H-ras-1 alleles, defined by MspI digestion, confers a relative risk for lung cancer of 2.0 (95% confidence interval, 0.5-7.3) for Caucasians and 3.2 (0.9-11.6) for African Americans (74 cases, 67 controls). The L-myc gene sequence has a restriction site (EcoR1) polymorphism between the second and third exons. Inheritance of restriction site-present alleles was reported to confer poor prognosis (presence of lymph node metastases) in Japanese lung cancer patients. This hypothesis was tested in both case-control study subjects (56 cases, 55 controls) and additional surgical cases (40), but no evidence was found to support the hypothesis in the U.S. population. The p53 gene is a tumor-suppressor gene that can encode either a proline or an arginine in the 72nd residue. No associations was found between the minor allele (proline) and diagnosis of lung cancer (76 cases, 68 controls).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Relationship of H-ras-1, L-myc, and p53 polymorphisms with lung cancer risk and prognosis. 148 64

Cellular oncogenes such as c-fos, c-jun and c-myc are expressed prior to estrogen-induced growth of normal target tissues such as rodent uterus. Transient increases in the levels of these genes are induced by the administration of estradiol and are followed by DNA replication. In this study, we examined the expression of these three oncogenes in estradiol-induced kidney tumors in Syrian hamsters in order to understand mechanistic aspects of hormonal carcinogenesis. Kidney tumors were induced in all male Syrian hamsters treated chronically with estradiol for 7 or 9 months, whereas neoplasms were not detected in animals treated for 5 months. mRNA levels of fos, myc and jun were elevated 15-, 4- and 6-fold respectively in kidney tumors of estradiol-treated hamsters (9 months) compared with age-matched untreated control kidneys. The expression of all three protooncogenes was also increased in the kidney tissue surrounding tumors, though there was no consistent pattern in the ratios of transcripts in the tumor and kidney tissues. After 7 months of estrogen treatment, kidney tumors also contained elevated amounts of c-fos, c-jun and c-myc transcripts at levels comparable with older tumors. In abdominal metastases of hamster kidney tumors, mRNA levels of fos, myc and jun were elevated 9-, 12- and 3-fold respectively over control levels. In kidneys of hamsters treated with estradiol for 5 months, in which tumors were not yet detected, the expression of protooncogenes was slightly increased. Ratios of c-fos, c-myc and c-jun in estrogen-treated (5 months) over control tissue were 1.4, 1.1 and 1.3 respectively. Overexpression of cellular oncogenes such as c-fos, c-jun and c-myc may have played a role in the induction and growth of kidney tumors by estradiol in hamsters.
Carcinogenesis 1992 Apr
PMID:Elevation of protooncogene messenger RNAs in estrogen-induced kidney tumors in the hamster. 157 13

Surgically resected fresh human tumors (16 malignant and 1 benign) in the head and neck regions were s.c. transplanted into scid mice. All malignant tumors (12 squamous cell carcinomas, 2 papillary adenocarcinomas and 1 adenoid cystic carcinoma) except one heavily irradiated squamous cell carcinoma could grow in scid mice. However, all of three squamous cell carcinomas of the maxillary sinus grew only in 50% of scid mice, and two of them failed to grow in the second transfer. The remainder were successfully transplantable for further generations, except one accidental case. A benign tumor, a follicular adenoma of the thyroid gland, was also accepted in scid mice and was transplantable for further generations, though its growth was very slow. Distant metastases were found in the lung only when poorly differentiated carcinomas were transplanted into scid mice, but did not occur until 90 days after the transplantation of well and moderately differentiated carcinomas. The histological characteristics of both malignant and benign tumors were retained well in all of the xenografts and metastatic lesions. Thus, scid mice seem useful to investigate not only the properties of benign and malignant human tumors but also the metastatic spread of tumors which threaten the life of cancer patients.
Carcinogenesis 1992 May
PMID:Growth and metastasis of fresh human benign and malignant tumors in the head and neck regions transplanted into scid mice. 158 97

Tricyclic antidepressants, such as amitriptyline (Elavil), and the nontricyclic agent, fluoxetine (Prozac), bind to growth-regulatory intracellular histamine receptors, associated with anti-estrogen binding sites in microsomes and nuclei. The prototype anti-estrogen binding site/intracellular histamine receptor ligand, N,N-diethyl-2-[4-(phenylmethyl)phenoxy]ethanamine HCl, inhibits normal cell proliferation in vitro but stimulates tumor growth in vivo. Because of their structural similarity to N,N-diethyl-2-[4-(phenylmethyl)phenoxy]ethanamine HCl, we carried out studies to determine whether amitriptyline and fluoxetine stimulate tumor growth and/or development in rodents at concentrations relevant to the treatment of human depression (equivalent human dose range, approximately 100-150 mg/day for amitriptyline and approximately 20-80 mg/day for fluoxetine). All experiments were performed blinded. In studies of growth stimulation of transplantable syngeneic tumors, groups of mice were inoculated s.c. with C-3 fibrosarcoma cells or given i.v. or s.c. injections of B16f10 melanoma cells, followed 24 h later by daily i.p. injections of saline, amitriptyline, or fluoxetine. Tumor latency (fibrosarcoma), aggregate tumor weight (s.c. injected melanoma), or time to death from pulmonary metastasis (i.v. injected melanoma) was determined; drug-induced stimulation of DNA synthesis in C-3 fibrosarcoma cells in vitro was correlated with tumor growth acceleration in vivo. In a mammary carcinogenesis model, the effects of chronic saline, amitriptyline, or fluoxetine administration on the rate and frequency of development of mammary tumors in rats fed dimethylbenzanthracene (DMBA) were compared. Eight of 20 amitriptyline- or fluoxetine-treated mice developed fibrosarcoma tumors by day 5, as compared to none of 20 saline controls (P less than 0.002). Similarly, 20 of 21 DMBA-treated rats receiving the antidepressant drugs developed 33 mammary tumors by week 15 as compared to 5 tumors in 4 of 7 DMBA-treated rats receiving saline (P less than 0.001). For both models, tumor latency decreased 30-40% and, in the DMBA model, tumor frequency increased greater than 2-fold in the antidepressant-treated rats as compared to controls. Stimulation of fibrosarcoma growth in vivo correlated with a corresponding bell-shaped drug-induced increase in DNA synthesis in vitro. While the median time to death from pulmonary metastases did not differ among groups given i.v. injections of melanoma cells, a significant (P less than 0.01) stimulation of growth of s.c. injected melanoma was observed in mice receiving the antidepressants.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Stimulation of malignant growth in rodents by antidepressant drugs at clinically relevant doses. 161 49

K-ras oncogene mutation has been shown to be a frequent event in pancreatic ductal adenocarcinomas induced by the carcinogen N-nitroso-bis(2-oxopropyl)amine in the hamster. The present study examines the mutational status of the K-ras oncogene in lesions that precede the appearance of invasive ductal adenocarcinomas. Syrian golden hamsters (80-100 g) received 12 weekly doses of 15 mg/kg N-nitroso-bis(2-oxopropyl)amine and were serially sacrificed at 8, 12, 14, 16, or 24 weeks following the initiation of treatment. Ten microns-thick sections of formalin-fixed paraffin-embedded pancreas were examined for hyperplasia, papillary hyperplasia, carcinoma in situ, and invasive and metastatic ductal carcinoma. Marked lesions of interest were scraped from the slide, subjected to polymerase chain reaction-mediated amplification of the first exon of the K-ras gene, and probed by oligonucleotide-specific hybridization for mutations at codon either 12 or 13. Of 186 samples assayed, K-ras codon 12 mutations were detected in 26% of hyperplasias, 46% of papillary hyperplasias, 76% of carcinoma in situ, 80% of adenocarcinomas, and 43% of lymph node metastases. Codon 12 mutations were exclusively G to A changes at the second position. Codon 13 mutations were only detected in 9 of 168 samples. These results suggest that K-ras activation is an early event in N-nitroso-bis(2-oxopropyl)amine-induced pancreatic carcinogenesis in the hamster.
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PMID:K-ras mutation is an early event in pancreatic duct carcinogenesis in the Syrian golden hamster. 164 42

A semi-purified corn-based diet containing 50 mg/kg of pure (not less than 90%) fumonisin B1 (FB1), isolated from culture material of Fusarium moniliforme strain MRC 826, was fed to a group of 25 rats over a period of 26 months. A control group of 25 rats received the same diet without FB1. Five rats from each group were killed at 6, 12, 20 and 26 months. The liver was the main target organ in the FB1-treated rats and the hepatic pathological changes were identical to those previously reported in rats fed culture material of F.moniliforme MRC 826. All FB1-treated rats that died or were killed from 18 months onwards suffered from a micro- and macronodular cirrhosis and had large expansile nodules of cholangiofibrosis at the hilus of the liver. Ten out of 15 FB1-treated rats (66%) that were killed and/or died between 18 and 26 months developed primary hepatocellular carcinoma. Metastases to the heart, lungs or kidneys were present in four of the rats with hepatocellular carcinoma. No neoplastic changes were observed in any of the control rats. Chronic interstitial nephritis was present in the kidneys of FB1-treated rats killed after 26 months. No lesions were observed in the esophagus, heart or forestomach of FB1-treated rats and this is contrary to previous findings when culture material of the fungus was fed to rats. It is concluded that FB1 is responsible for the hepatocarcinogenic and the hepatotoxic but not all the other toxic effects of culture material of F.moniliforme MRC 826 in rats.
Carcinogenesis 1991 Jul
PMID:Toxicity and carcinogenicity of the Fusarium moniliforme metabolite, fumonisin B1, in rats. 164 15


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