Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019204 (hepatocellular carcinoma)
 71,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied the basis of rejection of retrovirus-infected tumor cells in guinea pigs by evaluating host response to injection of mixtures containing retrovirus-infected tumor cells and, antigenically and biologically distinct, uninfected tumor cells (line 10). After intradermal injection, line 10 grew progressively, metastasized to regional lymph nodes, and led to death of animals; line 107C3 4070A, a murine leukemia virus-infected fibrosarcoma cell line, grew for approximately 1 week and then regressed. Growth of the line 10 hepatoma was suppressed when the hepatoma cells were mixed with viable 107C3 4070A cells before injection into strain 2 guinea pigs. Viable virus-infected 107C3 cells were more effective than irradiated virus-infected cells in suppressing line 10 growth; mixture of line 10 with murine leukemia virus 4070A alone did not inhibit line 10 growth. Suppression of growth of line 10 cells by admixed murine leukemia virus 4070A-infected cells was less effective in animals with established viral immunity. Cyclophosphamide inhibited suppression of line 10 at sites of injection of virus-infected cells. Infection of line 10 with murine leukemia virus in vitro required cocultivation of line 10 cells with murine leukemia virus-infected fibrosarcoma cells; virus alone did not lead to acquisition of murine leukemia virus antigens by line 10 cells.
 ...
PMID:Rejection of retrovirus-infected tumor cells in guinea pigs: effect on bystander tumor cells. 631 16

A study of the effects of local tumor radiation alone (1500R) and cyclophosphamide alone (150 mg/kg) on the experimental solid tumor rat hepatoma 3924A has been completed. Cyclophosphamide was more effective in controlling tumor growth than either radiation or 5-fluorouracil (5-FU) (150 mg/kg) previously reported. Parallel recovery of bone marrow with increasing animal survival in "split dose" cyclophosphamide toxicity studies (as with 5-FU) indicates that bone marrow is the critical organ for sequential chemotherapy. Recovery of intestinal mucosa following cyclophosphamide (and 5-FU) occurred much earlier than recovery of bone marrow, substantiating the fact that bone marrow is the critical organ governing the time of administration of a second series of chemotherapeutic agents. The longest period of time (seven days) between delivery of radiation and administration of cyclophosphamide resulted in the most effective use of the two modalities. Tumor growth delay was 1.2 times greater than the additive effects of each agent given alone. Radiation and cyclophosphamide given at other time intervals resulted in either an additive or less than additive effect. One of the greatest difficulties to overcome in the more effective clinical use of combined modality therapy is increased toxicity. In these studies, the least host toxicity occurred when the effects of combined radiation and cyclophosphamide on the tumor were greatest. Results of experimental studies to date suggest that sequential combined modality therapy may be given at a time of maximum tumor growth rate that occurs following the previous treatment series. Since the time of maximum tumor growth rate occurs after recovery of the bone marrow from the previous treatment series, combined chemotherapy-radiotherapy schedules of this type should permit sequential administration of chemotherapeutic agents, such as 5-FU and cyclophosphamide, at the time of enhanced tumor sensitivity and diminished host toxicity.
 ...
PMID:Solid tumor models for the assessment of different treatment modalities. XIII. Comparison of response and recovery of host and solid tumor to cyclophosphamide and radiation. 737 10

The present studies were undertaken using a cloned erythropoietin (Ep) producing hepatocellular carcinoma cell line (Hep3B) to attempt to correlate the receptor binding properties and biological activities of 5'-N-ethylcarboxamideadenosine (NECA), N6-cyclohexyladenosine (CHA) and N6-cyclopentyldenosine (CPA). Ep and cAMP levels in cultures of Hep3B cells in response to these adenosine analogues were measured by radioimmunoassay. Receptor binding affinities of the adenosine analogues were determined by measuring inhibition of binding of [3H] NECA to Hep3B cell membranes. Scatchard analysis of [3H]NECA to Hep3B cell membranes. Scatchard analysis of [3H]NECA binding to Hep3B cell membranes indicates a single class of binding sites with a dissociation constant of 431 nM and a binding capacity of 573 fmol/mg protein. The adenosine analogues tested produced a significant increase in Ep secretion and cAMP accumulation (ED50 for cAMP accumulation, NECA = 3.3 x 10(-7) M, CHA = 4.2 x 10(-6) M, CPA = 2.2 x 10(-6) M). In addition, NECA showed a higher binding affinity (Ki, 3.8 x 10(-7) M) for Hep3B cell membranes in comparison with CHA (Ki, 6.3 x 10(-6) M) and CPA (Ki, 3.9 x 10(-6) M). These results indicate that the rank order for potency for NECA, CHA and CPA in their binding to Hep3B cell membrane receptors correlates very well with their biological effects on Ep secretion and cAMP accumulation in Hep3B cells.
 ...
PMID:Adenosine A2 receptor modulation of erythropoietin secretion in hepatocellular carcinoma cells. 812 56

The concentration of cystatin C, a cysteine proteinase inhibitor, was measured during the treatment of murine LS lymphosarcoma with cyclophosphamide and HA-1 murine hepatoma with the antitumor drug Ukrain. It was shown that concentrations of cystatin C were very low in both the tumor tissues studied (HA-1 hepatoma cells and LS lymphosarcoma); increased cystatin C concentrations were found only in Ukrain-treated murine hepatoma, suggesting the mechanism of antitumor effect of this drug. Cyclophosphamide treatment in LS lymphosarcoma did not influence the concentration of cystatin C in tumor cells. At the same time, a marked increase in cathepsin B and cathepsin L activity in LS lymphosarcoma was found, indicating the involvement of apoptosis in the mechanism of antitumor action of cyclophosphamide. While the DNA from untreated LS lymphosarcoma was very homogenous and its molecular weight was high, the DNA from tumors of treated mice broke down, giving rise to the ladder figure characteristically produced by cells dying from apoptosis. Evidence was obtained that cyclophosphamide-induced tumor regression was effected by apoptosis.
 ...
PMID:Cystatin C in LS lymphosarcoma and HA-1 hepatoma treated with Ukrain and cyclophosphamide and involvement of apoptosis. 1134 40

Cystatin C is the best known extracellular endogenous cysteine proteinase inhibitor and has been studied as a possible index of tumor growth and as a marker of the effectiveness of antitumor therapy. The aim of this study was to evaluate cystatin C concentrations in murine tumor tissues (compared with other organs not directly involved with tumor development, such as the liver and spleen) during treatment with several antitumor drugs (Ukrain and/or cyclophosphane). Cystatin C concentrations in murine tissues and biological fluids was determined by enzyme-linked immunosorbent (ELISA) assay. The cystatin C ELISA test is a sandwich immunoassay, which uses immobilized rabbit antihuman cystatin C Pab and mouse antihuman cystatin C Mab-HRP (monoclonal antibodies, conjugated with horseradish peroxidase). We observed decreased serum cystatin C concentrations compared with controls in all nontreated tumor models: HA-1 hepatoma (solid and ascitic forms), lung adenocarcinoma (solid and ascitic forms) and LS lymphosarcoma. In the ascitic fluid of mice with HA-1 hepatoma the cystatin C concentration was much lower than in the serum of the same mice (about 20-fold lower). In the HA-1 model of hepatoma cells cystatin C concentration decreased about 2-3-fold compared with the control (intact liver) and Ukrain significantly increased the cystatin C concentration. Cyclophosphane treatment of LS lymphosarcoma significantly increased the cystatin C concentration in serum. Cyclophosphane treatment (50 mg/kg, single injection) increased cystatin C by up to 8-fold more in tumor issue. Ukrain treatment of LS lymphosarcoma was also followed by increased levels of cystatin C in tumor tissue (4-fold); cyclophosphane plus Ukrain had a similar positive effect. In the group with LS lymphosarcoma Ukrain or cyclophosphane plus Ukrain treatment induced a significant increase in cystatin C concentration in liver. Liver cystatin C concentration decreased in the HA-1 hepatoma group and treatment with Ukrain or carboxymethylated beta-1, 3-glucan (CMG) increased this index in both groups. Spleen cystatin C concentrations decreased about 5-fold in LS lymphosarcoma compared with controls and combined treatment with cyclophosphane plus Ukrain restored the index to the normal value. We can conclude that both murine tumors studied were characterized by low cystatin C concentrations in tumor tissues and decreased cystatin C concentrations (to a lesser degree) were also observed in liver and spleen as a result of the "toxic" effect of tumor bearing. Effective treatment in all cases (especially with Ukrain or a combination of cyclophosphane plus Ukrain) induced a significant increase in cystatin C. Obviously, the decrease in cystatin C concentration predominantly in tumor tissue was connected with tumor development and restoration of cystatin C level may be used as a marker of efficacy of antitumor therapy.
 ...
PMID:Cysteine proteinase inhibitor level in tumor and normal tissues in control and cured mice. 1134 42

Oxidative stress is considered to be one of the important mechanisms involved in carcinogenesis. In our previous study, gadolinium endohedral metallofullerenol ([Gd@C82(OH)22]n nanoparticles) have shown high inhibitory activity on hepatoma cell (H22) growth in mice. To explore the antioxidative functions of nanoparticles, we investigated the biodistribution of [Gd@C82(OH)22]n nanoparticles, the changes of blood coagulation profiles, the metabolism of reactive oxygen species (ROS) in the tumor-bearing mice as well as the possible relationships between nanoparticles treatment and ROS production in this paper. The activities of hepatic superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST) and catalase (CAT) as well as the levels of reduced glutathione (GSH), protein-bound thiols and malondialdehyde (MDA) were compared between the tumor-bearing mice and normal mice. Transplanted tumors were grown in mice by subcutaneous injection of murine hepatoma cells in the mice. The comparison of the above parameters between nanoparticles and cyclophosphamide (CTX) therapy were also investigated. [Gd@C82(OH)22]n administration can efficiently restore the damaged liver and kidney of the tumor-bearing mice. All the activities of enzymes and other parameters related to oxidative stress were reduced after [Gd@C82(OH)22]n treatment and tended closely to the normal levels. The results suggest that [Gd@C82(OH)22]n nanoparticle treatment could regulate ROS production in vivo.
 ...
PMID:Antioxidative function and biodistribution of [Gd@C82(OH)22]n nanoparticles in tumor-bearing mice. 1643 73

It is known that, besides its direct cytotoxic effect as an alkylating chemotherapeutic agent, cyclophosphamide also has immuno-modulatory effects, such as depletion of CD4+CD25+ regulatory T cells. However, its optimal concentration has not yet been fully elucidated. Therefore, we first compared the effects of different doses of cyclophosphamide on T cell subsets including CD4+CD25+ T cells in mice. Cyclophosphamide (20 mg/kg) decreased the numbers of splenocytes, CD4+ and CD8+ T cells by approximately 50%, while a decline in CD4+CD25+ T cell number was more profound, leading to the remarkably lower ratios of CD4+CD25+ T cells to CD4+ T cells. In contrast, 200 mg/kg cyclophosphamide severely decreased the numbers of all the T cell subsets by > 90% although the decreased ratios of CD4+CD25+ T cells to CD4+ T cells were still observed. Next, low-dose cyclophosphamide significantly inhibited in vivo growth of murine hepatoma MH129 tumor in immuno-competent but not immuno-deficient mice. This anti-tumor effect was abolished by CD4+CD25+ T cell repletion. In contrast, high-dose cyclophosphamide exhibited similar anti-tumor effects in both mice. In addition, contrary to antibody-mediated CD4+CD25+ T cell depletion, administration of low-dose cyclophosphamide after tumor inoculation was more efficacious than the prior administration. Our data show that low-dose cyclophosphamide selectively depletes CD4+CD25+ T cells, leading to enhanced anti-tumor effects against pre-existing tumors, while the anti-tumor effect of high-dose cyclophosphamide is solely attributed to its direct cytotoxicity. These findings appear to be highly crucial in a clinical setting of combined chemotherapy and immunotherapy for cancer treatment.
 ...
PMID:Different mechanisms for anti-tumor effects of low- and high-dose cyclophosphamide. 1678 37

Cyclophosphamide (CTX) is in the nitrogen mustard group of alkylating antineoplastic chemotherapeutic agents. It is one of the most frequently used antitumor agents for the treatment of a broad spectrum of human cancers. Thioredoxin reductase (TrxR) catalyze the NADPH-dependent reduction of thioredoxin and play an important role in multiple cellular events related to carcinogenesis including cell proliferation, apoptosis, and cell signaling. This enzyme represents a promising target for the development of cytostatic agents. The purpose of this study is to determine whether CTX could target TrxR in vivo. Lewis lung carcinoma and solid H22 hepatoma treated with 50-250 mg/kg CTX for 3 h lost TrxR activity in a dose-dependent fashion. Over 75% and 95% of TrxR activity was lost at the dose of 250 mg/kg. There was, however, a recovery of TrxR activity such that it attained normal levels by 120 h after a dose of 250 mg/kg. In addition, we found that CTX caused a preferential TrxR inhibition over other antioxidant enzymes, such as glutathione peroxidase, catalase, and superoxide dismutase. We also used ascites H22 cells to investigate cancer cells response after TrxR was inhibited by CTX in vivo since CTX is needed to be activated by liver cytochrome P450 enzymes. The time course and dose-dependent changes of cellular TrxR activity were similar with those in tumor tissue. CTX caused a dose-dependent cellular proliferation inhibition which was positively correlated with TrxR inhibition at 3 h. Furthermore, when 3 h CTX-treated cells with various TrxR backgrounds, harvested from ascites-bearing mice, were implanted into mice, the proliferations of these cells were again proportionally dependent on TrxR activity. The TrxR inhibition could thereby be considered as a crucial mechanism contributing to anticancer effect seen upon clinical use of CTX.
 ...
PMID:Cyclophosphamide as a potent inhibitor of tumor thioredoxin reductase in vivo. 1715 7

Cytotoxin III (CTX III), a basic polypeptide with 60 amino acid residues isolated from Naja naja atra venom, have potential therapeutic activity in tumor therapy. However, the therapeutic effect in solid tumor treatment with CTX III are still largely unknown. In the present study, we investigated whether CTX III affects cell growth and cell cycle progression of hepatocellular carcinoma cell (HepG2). We found that the proliferation of HepG2 cell was inhibited by CTX III, to some extent, in a time- and dose-dependent manner (IC50 2.58microg/ml at 24h). Flow cytometric analysis and annexin V labeling also demonstrated that CTX III increased the percentage of apoptotic cells being associated with cell cycle arrest at S-phase. Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot revealed that cyclin D1, cyclin A and cyclin E, which involved in cell apopotosis and cell cycle progression, were down regulated both at transcription and translation levels. CTX III-induced caspase-8, -9 and caspase-3 activation, generation of truncated Bid, releasing of cytochrome c and the change of Bcl-2/Bax ratio on protein and mRNA levels. These findings demonstrated that cyclin D1, cyclin B and cyclin A down-regulation, change of Bcl-2/Bax ratio and caspase-8 and -9 activation contribute to CTX III-induced HepG2 cell apoptosis.
 ...
PMID:Apoptosis of human hepatocellular carcinoma cell (HepG2) induced by cardiotoxin III through S-phase arrest. 1898 2

T-cell costimulatory molecules such as 4-1BB may provide a distinct and important signal for promoting positive immune regulation. 4-1BB is thought to have potential use as a cancer immunotherapeutic drug. In our previous study, a nonreplicative adenovirus (Ad.4-1BB scFv) carrying single-chain Fv fragments (scFv) specific for the 4-1BB gene (anti-4-1BB scFv) possessed remarkable in vivo anti-hepatoma efficacy. However, monotherapy achieved by triggering 4-1BB signaling was not sufficient to induce eradicative antitumor activities in low immunogenic tumors. It is of great interest to explore any possible synergistic antitumor effect of 4-1BB signaling combined with low dose cyclophosphamide (CTX), which is well documented to inhibit the suppressive capability of regulatory T-cells in mice and humans. In the present study, recombinant nonreplicative adenoviruses carrying an anti-4-1BB scFv gene were generated, characterized and explored for their stimulation of antilung tumor (TC-1) immunity in immunocompetent C57BL/6 mice. Compared to adenovirus and cyclophosphamide alone, adenovirus-mediated anti-4-1BB scFv in combination with low dose CTX treatment could obviously augment the antitumor activity, in which some established TC-1 tumors were eradicated and the survival of mice was significantly extended. This synergistic antitumor effect could be largely attributed to the depletion of T regulatory cells induced by low dose CTX. These findings may provide a new and promising strategy for immunogene therapy against cancer.
 ...
PMID:Anti-4-1BB scFv immunogene therapy and low dose cyclophosphamide exhibit a synergistic antitumor effect in established murine lung tumors. 1941 62


<< Previous 1 2 3 4 Next >>