Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0596263 (carcinogenesis)
 64,820 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We examined whether orally administered RBS (rice bran saccharide), prepared from rice bran by hot water extraction, increases immunocompetence, inhibits gastrointestinal carcinogenesis with N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG) or shows an antitumor effect. After the administration of RBS, phytohemagglutinin (PHA)- and pokeweed mitogen (PWM)-stimulated blastogenesis of lymphocytes derived from the mesenteric lymph nodes and peripheral blood was enhanced, and the helper/suppressor T-cell ratio was elevated, and migration activity of peritoneal macrophages was also increased in rats treated continuously with ENNG. ENNG-induced gastrointestinal carcinomas were observed in 43% of those administered RBS (ENNG-RBS) as compared with 88% in the control (ENNG) and 94% in the prednisolone (PRD) group (ENNG-PRD). The 12-month survival rate of rats bearing gastrointestinal cancer was 58% in the ENNG-RBS group as compared with 25% in the ENNG group and 15% in the ENNG-PRD group. RBS prevented the reduction in immunocompetence in the course of carcinogenesis, suppressed carcinogenesis, and prolonged the survival of rats with gastrointestinal cancer. Antitumor activities of RBS are thought to be a kind of host mediated action. The growth inhibition ratio of transplantable ENNG-induced cancer in Wistar rats was 42.1% in the RBS and 51.8% in the 5-FU group. Since little is known about the potent antitumor activity of alpha-glucan, it would be interesting to consider the relationship between the structure and the biological activities of polysaccharides.
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PMID:Antitumor effect of RBS (rice bran saccharide) on ENNG-induced carcinogenesis. 162 34

Alstonine, serpentine and sempervirine, when used at appropriate concentrations cure a relatively important proportion of BALB/C mice inoculated with transplantable YC8 lymphoma ascites cells, as well as Swiss mice bearing Ehrlich ascites carcinoma cells. The development of some solid tumors was only partially prevented. However, when one alkaloid was administered in association with either 5-FU, daunorubicin, 1-(2-chloroethyl) nitrosourea (CCNU) or cyclophosphamide (CP) to mice bearing either ascites carcinoma cells or solid tumors, a high rate of cure was obtained without toxicity. The role of the three alkaloids in the curing of mice and prevention of carcinogenesis is discussed.
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PMID:Three alkaloids as selective destroyers of cancer cells in mice. Synergy with classic anticancer drugs. 370 65

Oral anti-cancer drugs play an important role in the treatment of breast cancer. Because these hormonal agents are related to mammary carcinogenesis and tumor growth, they are used not only for therapy but also to prevent the onset of the disease. Tamoxifen, toremifene, fadrozole and other aromatase inhibitors, goserelin, leuprolin and MPA are used widely in Japan as hormonal anti-cancer drugs. In addition oral anti-cancer chemotherapeutic agents, such as cyclophosphamide, 5-FU, 5'-DFUR, FT and UFT are used for breast cancer. The combination of these hormonal and chemotherapeutic agents produces good clinical results in curing the disease. Oral drugs are superior to injected drugs with regard to the QOL of patients.
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PMID:[Recent development of oral anti-cancer drugs for breast cancer]. 1006 92

The cyclin-dependent kinase inhibitor p27Kip1 is a negative regulator of cell proliferation. Its expression is known to be altered in a proteasome-dependent manner without changes in DNA level. Reduced expression of p27Kip1 is associated with aggressive behavior in a variety of human cancers. We investigated expression of p27Kip1 protein in human breast cancer using immunohistochemistry to assess its biologic implication along with cell-cycle analysis by flow cytometry. A total of 68 patients with invasive ductal cancer received adjuvant chemotherapy with cyclophosphamide, methotrexate, and 5-FU every 3 weeks for six cycles. In epithelial cells of normal and benign breast disease, expression of p27Kip1 was well preserved while its expression markedly decreased in breast cancer (45 of 68). Expression of p27Kip1 is significantly reduced in poorly differentiated cancers and in the advanced stage of the disease. Levels of p27Kip1 expression correlated with cell populations in G0/G1 phase of the cell cycle. In survival analysis, p27Kip1 was useful to predict disease free survival but not overall survival of the patients after adjuvant chemotherapy. In summary, p27Kip1 seems to have a role in the cell proliferation and differentiation process during carcinogenesis of breast cancer. The results of the present study suggest that p27Kip1 can be used in predicting response to systemic chemotherapy in a subset of patients with breast cancer.
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PMID:Reduced expression of p27Kip1 protein is associated with poor clinical outcome of breast cancer patients treated with systemic chemotherapy and is linked to cell proliferation and differentiation. 1048 43

Thymidylate synthase and thymidine kinase are key enzymes involved in the de novo and salvage pathways for pyrimidine nucleotide synthesis, respectively. Thymidylate synthase is inhibited by 5-fluorodeoxyuridine monophosphate, forming an inactive ternary complex with intracellular folate. We investigated the effects of 1-(2-tetrahydrofuryl)-5-FU plus uracil (UFT) with or without leucovorin on 1,2-dimethylhydrazine-induced rat colorectal carcinomas. Thirty-week administration of UFT with or without leucovorin markedly suppressed both colorectal carcinogenesis and tumor growth, resulted in the increase of thymidylate synthase inhibition and the decrease of thymidine kinase activity in the tumor cells. These results indicate that the combination of UFT with leucovorin could be useful in the development of pre- and post-operative adjuvant chemotherapy programs.
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PMID:Effects of long-term administration of UFT plus leucovorin on colorectal tumors induced with 1,2-dimethylhydrazine in rats. 1069 23

Retinoid is one of the most promising substances for chemoprevention and anti-cancer effect. Retinoid has the following reported actions: induction of cell differentiation, control of cancer growth, repair of the precancerous lesion, prevention of the secondary carcinogenesis, control of angiogenesis and prevention of metastasis, and immunostimulation. In the present study, retinoid modified the cell cycle, reinforced the G1 check mechanism which is lost in cancer cells and induced apoptosis. Retinoid augmented the membrane permeability of anti-cancer drugs such as 5-FU, and reduced the exocytosis of anti-cancer drugs by suppressing the expression of the transport protein cMOAT. Retinoid also suppressed the invasive growth of the cancer cells. With the FAR therapy regimen (5-FU and retinil palmitate with radiation) and subsequent surgery, the disease-specific five-year survival rate was close to 50% in various head and neck cancers. Thus, the chemoprevention and anti-cancer effects of retinoid may play an important role in the preservation of organs and QOL.
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PMID:[Chemoprevention and FAR therapy regimen comprised of 5-fluorouracil, vitamin A and radiation]. 1132 78

We earlier showed that lovastatin potentiated the chemopreventive effects of sulindac against colon neoplasia in a rodent model and augments apoptosis induced by 5-FU and cisplatin in human colon cancer cells. In the present study, we investigated effects of lovastatin in spontaneously immortalized rat intestinal epithelial cells, IEC-18 and their K-ras transformed clones. Lovastatin induced morphologic changes (cell rounding and detachment) and apoptosis that were not influenced by K-ras mutations, but were prevented by geranylgeranyl-pyrophosphate or by mevalonate. Clostridium difficile toxin B, which directly inactivates rho, induced similar morphologic changes and apoptosis. Cycloheximide prevented these effects of lovastatin, but not C. difficile toxin B. Lovastatin decreased the amounts of membrane bound rhoA and rhoB. Cycloheximide and geranylgeranyl-pyrophosphate prevented lovastatin induced morphologic changes and apoptosis but did not inhibit lovastatin-induced changes in membrane translocation of rho. Our data suggest that lovastatin induces morphologic changes and apoptosis by inhibiting geranylgeranylation of small GTPases of the rho family and thereby inactivating them. Restoration of membrane translocation of rho is not necessary for preventing lovastatin-induced morphologic changes or apoptosis.
Carcinogenesis 2002 Mar
PMID:Mechanism of lovastatin-induced apoptosis in intestinal epithelial cells. 1189 68

Despite recent additions to the armory of chemotherapeutic agents for colorectal cancer (CRC) treatment, the results of chemotherapy remain unsatisfactory. 5-Fluorouracil (5-FU) still represents the cornerstone of treatment and resistance to its actions is a major obstacle to successful chemotherapy. Therefore, new active agents in CRC and agents that increase the chemosensitivity of cancer cells to 5-FU are still urgently required. Violacein, a pigment isolated from Chromobacterium violaceum in the Amazon river, has a diverse spectrum of biological activities, and represents a novel cytotoxic drug with known antileukemic properties. To assess the suitability of violacein as a chemotherapeutic agent in CRC its cytotoxic effects were evaluated both as a single agent and in combination with 5-FU. Its underlying mechanisms of action were further investigated by studying its effects on the cell cycle, apoptosis and cell survival pathways [phosphatidylinositol-3-kinase/Akt, p44/42 mitogen activated protein kinase and nuclear factor kappaB (NF-kappaB)] in colon cancer cell lines. Violacein inhibits the growth of all four colon cancer cell lines tested. It induces apoptosis, and potentiates the cytotoxic effect of 5-FU in a poorly differentiated microsatellite unstable cell line (HCT116). Violacein causes cell cycle block at G(1), upregulates p53, p27 and p21 levels and decreases the expression of cyclin D1. Violacein leads to dephosphorylation of retinoblastoma protein and activation of caspases and a pancaspase inhibitor abrogates its biological activity. Our data provide evidence that violacein acts through the inhibition of Akt phosphorylation with subsequent activation of the apoptotic pathway and downregulation of NF-kappaB signaling. This leads to the increase in chemosensitivity to 5-FU in HCT116 colon cancer cells. Taken together, our findings suggest that violacein will be active in the treatment of colorectal tumors and offers new prospects for overcoming 5-FU resistance.
Carcinogenesis 2006 Mar
PMID:Violacein synergistically increases 5-fluorouracil cytotoxicity, induces apoptosis and inhibits Akt-mediated signal transduction in human colorectal cancer cells. 1634 70

The present work was conducted to further examine the effects of thymosin beta-4 (Tbeta4) upregulation on the apoptosis of SW480 colon cancer cells induced by T cells and various chemotherapeutic agents because reduced susceptibility to the cytotoxicity of an anti-Fas IgM (CH-11) in Tbeta4-overexpressing cells has previously been reported by us. As expected, Tbeta4 overexpressers were also more resistant to the killing effect of FasL-bearing Jurkat T cells. On the other hand, pretreating these cells with an MMP inhibitor restored not only their Fas levels but also their sensitivity to CH-11, suggesting a pivotal role of MMP in downregulating Fas in Tbeta4 overexpressers. Interestingly, while the susceptibilities of Tbeta4 overexpressers to 5-FU and irinotecan remained unchanged, they were more resistant to doxorubicin and etoposide which triggered apoptosis via a mitochondrial pathway. Concordantly, activation of both caspases 9 and 3 in Tbeta4 overexpressers by the two aforementioned topoisomerase II inhibitors was dramatically abrogated which could be accounted mainly by an increased expression of Survivin, a critical anti-apoptotic factor. Finally, poor survival was found in stage III colon cancer patients whose tumors were stained positively by the anti-Survivin antibody. Thus, advantages such as immune evasion and resistance to anticancer drug-induced apoptosis acquired by colon cancer cells through Tbeta4 overexpression might facilitate their survival during metastasis and chemotherapy.
Carcinogenesis 2006 May
PMID:Overexpression of thymosin beta-4 renders SW480 colon carcinoma cells more resistant to apoptosis triggered by FasL and two topoisomerase II inhibitors via downregulating Fas and upregulating Survivin expression, respectively. 1636 25

The role of epidermal growth factor receptor (EGFR)-driven signaling in different stages of colorectal carcinogenesis, as well in the acquisition of therapy resistance, has been established. Multiple strategies have been developed for the therapeutic targeting of EGFR. Cetuximab is a chimeric monoclonal antibody selective for EGFR with efficacy alone or in combination with irinotecan in the treatment of metastatic colorectal cancer patients, who have progressed to using irinotecan-containing chemotherapy. Cetuximab is well tolerated and does not exacerbate the toxicity of concomitant chemotherapy. Based on this data, the combination of cetuximab with standard chemotherapy regimens such as irinotecan/ 5-FU/folinic acid (FA) or oxaliplatin/5-FU/FA are currently being investigated in Phase III trials for chemotherapy-naive patients with metastatic colorectal cancer.
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PMID:Cetuximab in the treatment of colorectal cancer. 1655 87


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