Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this study, we examined whether the production of hydrogen peroxide by peroxisome proliferators causes oxidative DNA damage in the form of 8-oxodeoxyguanosine (8-oxodG) and hepatic injury, and whether it is related to their tumor-promoting or carcinogenic activities in female rats treated with the peroxisome proliferators clofibrate and perfluorodecanoic acid (PFDA). Clofibrate has tumor-promoting and carcinogenic activities, whereas PFDA does not. We also tested whether peroxisome proliferators directly induce mutagenic events in Salmonella typhimurium strains TA 98 and TA 1537. Rats were treated either by 5% clofibrate in diet or by an i.p. injection of corn oil containing 10 mg/kg body weight of PFDA every week for 2 or 8 weeks. 8-OxodG in liver DNA was analyzed by HPLC coupled with an electrochemical detector. Hepatic injury was evidenced by liver enlargement and by levels of serum enzymes, aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and hepatic gamma-glutamylpeptidase (gamma-GT) activity. Clofibrate and PFDA increased the activity of catalase about or less than 2-fold, whereas FAO activity was increased about 6 to 7-fold by clofibrate and about 3 to 4-fold by PFDA. Neither clofibrate nor PFDA induced mutation at any dose tested. Clofibrate significantly increased the formation of 8-oxodG, but PFDA only slightly increased. Serum AST and ALT levels, and hepatic gamma-GT activity were not significantly changed at both time points, whereas the ratio of liver/body weight was significantly increased by clofibrate and PFDA at 8 weeks. These data imply that the magnitude of the production of hydrogen peroxide-generated FAO is related to the induction of oxidative DNA damage by peroxisome proliferators, and their tumor-promoting or carcinogenic activities. However, the effect of hydrogen peroxide in hepatic injury is not clear.
 ...
PMID:Formation of 8-oxodeoxyguanosine in liver DNA and hepatic injury by peroxisome proliferator clofibrate and perfluorodecanoic acid in rats. 964 51

Tumour markers correlate strongly with prognosis based on tumour burden and surgical resectability. If chemotherapy is extremely effective in certain stage of the disease, the sensitive marker may be of great use in monitoring disease response and drug treatment. Hence, this study was launched to evaluate the changes in tumour marker enzymes like lactate dehydrogenase (LDH), glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT), alkaline phosphatase, and acid phosphatase in before and after 3 and 6 months tamoxifen treated breast cancer patients. In addition, the changes in serum glycoproteins viz., hexose, hexosamine, and sialic acid and lysosomal enzymes such as N-acetyl-beta-D-glucosaminidase, beta-D-galactosidase, and beta-D-glucuronidase were analysed in these patients. These values were compared with their age matched healthy control subjects. At 6 months evaluation, the tamoxifen treated postmenopausal breast cancer women showed a statistically significant decreased (p < 0.001, 0.05 respectively) levels of LDH, SGOT, SGPT, alkaline and acid phosphatases than their baseline values. Similarly, the levels of hexose, hexosamine, and sialic acid and N-acetyl-beta-D-glucosaminidase, beta-D-galactosidase, and beta-D-glucuronidase were decreased significantly (p < 0.001) in tamoxifen received postmenopausal women. The result of this study suggested that tamoxifen potentially retard the metastasis of breast cancer as well as the bone demineralisation in postmenopausal breast cancer women. Thus, tamoxifen may also have its antitumour activity through its beneficial effects on tumour marker enzymes and serum proteins in breast cancer women.
 ...
PMID:The salubrious effect of tamoxifen [correction of Tamaxifen] on serum marker enzymes, glycoproteins, and lysosomal enzymes level in breast cancer woman. 974 15

A 9-year-old spayed female Poodle was admitted because of vomiting of 3 weeks' duration, lethargy, and anorexia. Palpation of the cranial portion of the abdomen elicited signs of pain. Principal laboratory abnormalities included mild segmented neutrophilia, lymphopenia, high serum alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase activities, and hyperbilirubinemia. Radiography revealed foamy appearing areas of mineral opacity in the region of the gallbladder. Ultrasonographically, a hyperechoic structure with acoustic shadowing was seen in the same region, and extrahepatic bile ducts were distended. Cholecystectomy was performed. The gallbladder wall felt thicker than normal and was bluish-white. Multiple choleliths were found in the gallbladder and extrahepatic bile ducts. Histologic examination revealed chronic proliferative lymphoplasmacytic cholecystitis with mineralization and a well-differentiated adenocarcinoma of the gallbladder neck. A diagnosis of porcelain gallbladder was made. The dog recovered without complications and was healthy 14 months after surgery. To our knowledge, porcelain gallbladder has not been reported in dogs. In human patients, it is defined as intramural mineralization of the gallbladder commonly associated with gallbladder neoplasia. Early recognition is important for appropriate surgical treatment.
 ...
PMID:Porcelain gallbladder associated with primary biliary adenocarcinoma in a dog. 978 80

Induction of replicative DNA synthesis (RDS) and mitoinhibitory effects were studied in the hepatocytes of F344 rats exposed in vivo to the methylating agents dimethylnitrosamine (DMN, hepatocarcinogen) and methylnitrosourea (MNU, non-hepatocarcinogen). Cytotoxicity and chromosome aberrations (CA) in rat liver were also investigated to clarify the cause of changes in RDS and mitoinhibitory effects, respectively. The animals were killed at different intervals (up to 14 days) after a single oral dose, or 1 day after 7 or 14 days of repeated oral doses. The hepatocytes were isolated and cultured with Williams' medium E to assess their RDS, mitoinhibitory effects and CA. Mitoinhibitory effects were investigated by monitoring their effect on epidermal growth factor-induced replicative DNA synthesis (EGF-induced RDS) in rat hepatocytes. Hepatotoxic effects were assessed by measuring aspartate transaminase and alanine transaminase in the plasma and by histopathological examination. In the single-dose study, DMN (20 mg/kg body weight (bw)) induced both RDS and hepatotoxicity. MNU (50 mg/kg bw) induced RDS without causing hepatotoxicity, and thus was classified as a mitogen. In the repeated-dose study, DMN (4 mg/kg bw) induced both RDS and hepatotoxicity, but MNU (10 mg/kg bw) induced neither. Both inhibition of EGF-induced RDS and induction of CA were observed in the hepatocytes of rats treated with DMN, but were not observed with MNU in both single and repeated dose studies. The mitoinhibitory effect of DMN persisted for 14 days after the single dose and time dependently increased for 14 days after repeated administration. This mitoinhibitory effect correlated positively with CA. The mitoinhibitory effect was thought to be attributable to the DNA-damaging effect that induces CA. We concluded that the differences which we found in this study between DMN and MNU contribute to the differences in their hepatocarcinogenicity. Our findings suggested that both cell proliferative and mitoinhibitory properties play an important role in tumor promotion, and measuring them may provide an ancillary index that is useful in predicting hepatocarcinogenicity.
 ...
PMID:A short-term assessment of tumor-promotion activity in the livers of rats treated with two genotoxic methylating agents: dimethylnitrosamine and methylnitrosourea. 978 84

The indolizidine alkaloid swainsonine, a potent inhibitor of Golgi alpha-mannosidase II, has been shown to reduce tumor cell metastasis, enhance cellular immune responses, and reduce solid tumor growth in mice. In our previous Phase I study, swainsonine administered by 5-day continuous infusion inhibited L-phytohemagglutinin-reactive N-linked oligosaccharide expression on peripheral blood lymphocytes. Significant toxicities included edema and elevated serum aspartate aminotransferase (AST). One patient with head and neck cancer had objective (>50%) tumor remission. Two patients showed symptomatic improvement. The objectives of this Phase IB trial were to examine the pharmacokinetics, toxicities, and biochemical effects of bi-weekly oral swainsonine at escalating dose levels (50-600 microgram/kg) in 16 patients with advanced malignancies and 2 HIV-positive patients unsuitable for conventional therapy. Eastern Cooperative Oncology Group performance status was </=2. The maximum tolerated dose was defined as 300 microgram/kg/day due primarily to serum AST abnormalities and dyspnea. Other adverse events present in >20% of patients included increase in serum AST (all patients), fatigue (n = 9), anorexia (n = 6), dyspnea (n = 6), and abdominal pain (n = 4). Inhibition of Golgi alpha-mannosidase II occurred in a dose-dependent manner. Examination of immunological parameters revealed a transient decrease in CD25(+) peripheral blood lymphocytes and, in seven of eight patients, an increase in CD4(+):CD8(+) ratios at 2 weeks. Serum drug levels peaked 3-4 h following a single oral dose in most patients and were proportional to dose at levels >/=150 microgram/kg. We conclude that oral swainsonine is tolerated by chronic intermittent administration at doses up to 150 microgram/kg/day. Adverse events considered drug related were similar to those observed in the infusional study but with fatigue and neurological effects also noted. Investigations of alternative dosing schedules with low starting doses are suggested for further clinical testing.
 ...
PMID:Phase IB clinical trial of the oligosaccharide processing inhibitor swainsonine in patients with advanced malignancies. 981 86

The interaction between glycolysis, glutaminolysis and tumor growth in WAG/Fra rnu/rnu rats has been investigated. Small tumors are characterized by a low conversion of glucose to lactate whereas the conversion of glutamine to lactate is high. In medium sized tumors the flow of glucose to lactate as well as oxygen utilization are increased whereas glutamine and serine consumption are reduced. At this stage the tumor cells start with glutamate and alanine production. Large tumors are characterized by a low oxygen and glucose supply but a high glucose and oxygen utilization rate. The conversion of glucose to glycine, alanine, glutamate, glutamine, and proline reaches high values and the amino acids are released. Pyruvate kinase increases with tumor weight and is positively correlated with an increase in glucose and oxygen utilization. The shift from glutamate consumption to glutamate production is correlated with an increase in glutamate dehydrogenase and glutamate oxaloacetate transaminase activity.
 ...
PMID:Pyruvate kinase and the interaction of amino acid and carbohydrate metabolism in solid tumors. 985 94

We previously reported that in vitro hypoxic condition enhanced VEGF level and its receptor expression in hepatic cancer cell line, HepG2. Transcatheter hepatic arterial embolization (TAE) therapy is one of the vasculo-occlusive and hypoxic challenges to hepatocellular carcinoma (HCC). Therefore, we examined the level of VEGF in sera of patients with HCC who underwent TAE during the course of the treatment. Thirty-eight patients with HCC and hepatitis C virus-positive cirrhosis were studied. Peripheral blood samples were taken before and 1, 3 and 7 days after TAE with informed consent. The serum levels of VEGF as well as hepatocyte growth factor (HGF), another hepatic remodeling factor, were measured. The molar ratio (BTR) of serum branched chain amino acid (BCAA) to tyrosine (Tyr), the serum levels of AST, ALT and LDH were also examined. Although the level of AST, ALT and LDH reached the peak value within 1 day after TAE, VEGF level increased significantly 7 days later. On the other hand, there were no significant alterations in the levels of HGF and BTR during the course of TAE. Although the level of HGF was significantly correlated with the level of VEGF before TAE, this correlation was no more observed after TAE. These data collectively suggest that VEGF may be secreted in response to clinical hypoxic intervention, TAE, independent of HGF or altered amino acid metabolism. VEGF may play a role as a sensitive marker for tumor ischemia.
 ...
PMID:Serum vascular endothelial growth factor in the course of transcatheter arterial embolization of hepatocellular carcinoma. 1033 62

The effect of dietary administration of cholic acid on tumorigenesis in the liver was investigated in male Fischer-344 rats after carcinogenic initiation by diethylnitrosamine (DEN); progression of liver tumors was examined in the rats fed 0.4% cholic acid-containing diet (CA group) and the rats fed standard diet (C group) at 15, 20 and 25 weeks after administration of DEN. The total bile acids and cholic acid in serum of CA group were 150 nmol/ml and 117 nmol/ml, being 31-fold and 51-fold higher than those in C group (p<0.0001, each). Serum AST and ALT were significantly higher in CA group than in C group at 15 weeks (p<0.01). Serum ALP was significantly higher in CA group than C group at each time point (p<0.01, each). Liver tumors, whose histology was hepatocellular carcinoma, developed at 15 weeks in both CA and C groups. However, tumor volume and tumor weight were significantly increased in CA group, compared to those in C group at each time point (p<0.001, p<0. 001, p<0.01, p<0.001, p<0.01 and p<0.05). The percentage of apoptotic cells in CA group at each time point was significantly lower than C group (p<0.05, p<0.01 and p<0.05). The percentage of bcl-2 positive tumor cells in C group at 20 weeks was 1.88+/-2.59%. However, it dramatically increased to 34.00+/-13.67% in CA group (p<0.0001). It was also higher in CA group than in C group at 15 and 25 weeks (p<0.05 and p<0.01). In addition, the bax-positive cells were higher in CA group than in C group at 20 weeks (p<0.05). These data suggest that oral administration of cholic acid promotes liver tumorigenesis initiated by DEN through reducing apoptosis mediated by overexpression of bcl-2.
 ...
PMID:Oral administration of cholic acid promotes growth of liver tumors initiated by diethylnitrosamine in rats. 1040 35

Natural products from plants are rich sources used for treating a number of diseases. Many of the pharmacological principles of the currently used anticancer agents have been initially isolated from plants. Most of the herbal drugs are a mixture of a number of plant ingredients. Their cumulative effect increases the efficacy of the drug in curing the diseases. Muthu Marunthu is a herbal formulation comprising of eight various plant ingredients, and has been claimed to possess antitumor effect. Therefore, attention has been focused on studying the various plant ingredients in the drug as a whole for its antitumor effects. It was observed that the growth rate in rats was normal and there was no change in blood parameters such as glucose, urea, proteins, cholesterol and also in the activities of pathophysiological enzymes such as lactate dehydrogenase (LDH), glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), alkaline and acid phosphatase after Muthu Marunthu administration. The tumor weight was found to be reduced in methylcholanthrene induced fibrosarcoma rats after Muthu Marunthu treatment. Elevated levels of glycocomponents of glycoproteins such as hexose, hexosamine, sialic acid and fucose in plasma of fibrosarcoma rats decreased significantly after Muthu Marunthu treatment. The DNA and RNA levels of liver and kidney, which were increased in fibrosarcoma rats, returned to near normal levels after Muthu Marunthu treatment. The vitamins such as A, C and E in plasma were decreased in fibrosarcoma rats but increased significantly after Muthu Marunthu treatment. The altered levels of copper, zinc and selenium in plasma have also been corrected after Muthu Marunthu treatment. These observations clearly suggested the antitumor potency of Muthu Marunthu in experimentally induced fibrosarcoma in rats.
 ...
PMID:Biochemical evaluation of antitumor effect of muthu marunthu (a herbal formulation) on experimental fibrosarcoma in rats. 1040 24

Oval cells are liver epithelial cells that proliferate during the early stages of hepatocarcinogenesis induced by a variety of chemicals. The oval cell lines OC/CDE 6 and OC/CDE 22 have been established in our laboratory at two time points (6 and 22 weeks) of the carcinogenic process and have been malignantly transformed by different procedures. During the transformation process, the glycolytic and glutaminolytic flux rates were consistently up-regulated and this process was accompanied by an overproportional increase in the activities of cytosolic hexokinase and 6-phosphogluconate dehydrogenase. In transformed oval cells, a strong correlation between the glycolytic flux rate and glutamine consumption as well as glutamate production was observed. Furthermore, the transport of glycolytic hydrogen, produced by the glyceraldehyde 3-phosphate dehydrogenase-catalyzed reaction, from the cytosol into the mitochondria by means of the malate-aspartate shuttle was enhanced, this being due to alterations in the activities of malate dehydrogenase and glutamate oxaloacetate transaminase. The up-regulation of the glycolytic hydrogen transport and the alterations in the glycolytic enzyme complex led to an enhanced pyruvate production at high glycolytic flux rates. Taken together, our data are further proof that a special metabolic feature (increased glycolysis and glutaminolysis) is characteristic for tumor cells and that the mechanisms by which this metabolic state is induced can be totally different.
 ...
PMID:Alterations in the glycolytic and glutaminolytic pathways after malignant transformation of rat liver oval cells. 1045 61


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