Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Numerous studies demonstrate that the chemopreventive effect of non-steroidal anti-inflammatory drugs on colon cancer is mediated through inhibition of cell growth and induction of apoptosis. For these effects non-steroidal anti-inflammatory drugs have been recently employed as sensitising agents in chemotherapy. We have shown previously that treatments with aspirin and NS-398, a cyclo-oxygenase-2 selective inhibitor, affect proliferation, differentiation and apoptosis of the human colon adenocarcinoma Caco-2 cells. In the present study, we have evaluated the effects of aspirin and NS-398 non-steroidal anti-inflammatory drugs on sensitivity of Caco-2 cells to irinotecan (CPT 11) and etoposide (Vp-16) topoisomerase poisons. We find that aspirin co-treatment is able to prevent anticancer drug-induced toxicity, whereas NS-398 co-treatment poorly affects anticancer drug-induced apoptosis. These effects correlate with the different ability of aspirin and NS-398 to interfere with cell cycle during anticancer drug co-treatment. Furthermore, aspirin treatment is associated with an increase in bcl-2 expression, which persists in the presence of the anticancer drugs. Our data indicate that aspirin, but not NS-398, determines a cell cycle arrest associated with death suppression. This provides a plausible mechanism for the inhibition of apoptosis and increase in survival observed in anticancer drug and aspirin co-treatment.
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PMID:Effect of non-steroidal anti-inflammatory drugs on colon carcinoma Caco-2 cell responsiveness to topoisomerase inhibitor drugs. 1198 87

The prognosis for patients with metastatic colorectal cancer is poor. Use of irinotecan (CPT-11, Camptosar) results in modest response rates of approximately 20% in refractory patients diagnosed with this advanced stage of disease and offers a side-effect profile that improves on that of previous standard treatments. Thalidomide (Thalomid) has antiangiogenic properties, and angiogenesis has been shown to influence the outcome of colon cancer patients. A good response rate and acceptable tolerability regarding gastrointestinal effects were demonstrated in a pilot study of the irinotecan/thalidomide combination in patients with metastatic colorectal cancer. This combination is being assessed at the University of Arkansas for Medical Sciences as second-line therapy in a phase II trial. Patients with metastatic colorectal cancer are receiving 350 mg/m2 of irinotecan every 3 weeks plus 400 mg/m2/d of thalidomide. Preliminary response and safety data are presented for 18 enrolled patients.
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PMID:Irinotecan/thalidomide in metastatic colorectal cancer. 1201 64

We administered an adjuvant chemotherapy of a bi-weekly low-dose CPT-11 + 5-FU on an outpatient basis to a patient with advanced sigmoid colon cancer and para-aortic lymph node metastasis. After 3 months, tumor markers fell to normal levels and the regression rate in the lymph node was over 80%. Throughout the period of treatment, there were no side effects, and there was no sign of recurrence for 6 months. In conclusion, we consider that with low-dose CPT-11 + 5-FU chemotherapy on an outpatient basis, the patient can maintain a high quality of life and show a massive effect, and that this regimen can be used as a first-line chemotherapy for advanced colon cancer.
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PMID:[A case of advanced colon cancer with para-aortic lymph node metastasis responding greatly to treatment by adjuvant chemotherapy of low-dose CPT-11 on an outpatient basis]. 1209 50

Premetrexed disodium (MTA) is a novel multitargeted antifolate that inhibits thymidylate synthase, dihydrofolate reductase, and glycinamide ribonucleotide formyltransferase. It exhibits a broad spectrum of activity against several human tumor types including colorectal cancer. Therefore, we evaluated the anti-proliferative potential of MTA combined with drugs known to exert therapeutic activity against colon cancer, including 5-fluorouracil, oxaliplatin, and SN38, the active metabolite of irinotecan. The effects of MTA, alone or combined with one of theses 3 drugs, were investigated in parental human HT29 colon cancer cells and in 5-fluorouracil-resistant counterparts HT29-5FU cells. These drugs were administered either simultaneously or sequentially. Functional interactions between MTA, 5-fluorouracil, oxaliplatin, and SN38 were evaluated using median-effect plot analysis. The drug combination and sequence with optimal effects were evaluated in athymic mice bearing human HT29 tumor cell xenografts. Combinations of MTA with 5-fluorouracil required high concentrations to achieved additive and/or synergistic effects. Simultaneous exposure to MTA and oxaliplatin led to synergistic activity in both parental and 5-fluorouracil-resistant human HT29 colon cancer cells, leading to additive antitumor effects and minimal toxicity in athymic mice bearing HT29 cell tumors. Synergism between MTA and SN38 was also observed in both parental and 5-fluorouracil-resistant HT29 cells. These results argue in favor of clinical trials of chemotherapy combining MTA with oxaliplatin or irinotecan (CPT-11), for the treatment of patients with colon cancer.
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PMID:Pemetrexed disodium combined with oxaliplatin, SN38, or 5-fluorouracil, based on the quantitation of drug interactions in human HT29 colon cancer cells. 1211 32

Treatment of the human colon cancer cells Hct116 with SN-38 (an active metabolite of CPT-11) resulted in G2 cell cycle arrest without induction of apoptosis. However, subsequent treatment of SN-38-treated Hct116 cells with flavopiridol induced apoptosis. One of the genes markedly up-regulated during cell cycle arrest by SN-38 and suppressed during apoptosis by SN-38 followed by flavopiridol in Hct116 cells is Drg1. We found that Drg1 had profound effects on SN-38 sensitivity. Inhibition of endogenous Drg1 expression in Hct116 cells by stable expression of an antisense (AS) Drg1 cDNA increased the sensitivity of cells to undergo apoptosis by SN-38. Clonogenic and apoptosis assays with AS Drg1-expressing cells showed a 2-fold decrease in the IC50 and a 4-5-fold increase in induction of apoptosis with SN-38. Conversely, the forced expression of Drg1 in SW620 cells increased the resistance of these cells to SN-38-induced apoptosis by 2-5-fold. Moreover, when xenografted in mice, AS Drg1-expressing Hct116 cells were 3-fold more sensitive to CPT-11 as compared with vector transfected Hct116 cells. Similarly, tumors established from Drg1 overexpressing SW620 cells were more resistant to CPT-11 as compared with tumors established from vector-transfected SW620 cells in mice. Taken together, our data suggest that Drg1 is a novel gene that plays a direct role in resistance to CPT-11. Inhibition of Drg1 may provide a new means to increase the sensitivity of colon cancer cells to CPT-11.
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PMID:Drg1, a novel target for modulating sensitivity to CPT-11 in colon cancer cells. 1212 25

Irinotecan (CPT-11), a recently introduced component of a standard chemotherapy for colorectal cancer, induces in colon cancer cell lines in vitro cell cycle arrest and apoptosis. Since sporadic colon carcinomas exhibit in 50-60% mutations in the p53 gene and in 10-15% an MSI phenotype due in the great majority of the cases to hMLH1 inactivation, we investigated how these lesions influence the cellular effects of CPT-11 by using colorectal carcinoma cell line HCT116 (which has the genotype p53(+/+),hMLH1(-)) and 2 derivative cell lines with the genotypes p53(+/+),hMLH1(+) and p53(-/-),hMLH1(-). CPT-11 treatment induced G2/M arrest in all 3 cell lines within 48 hr. In the p53(+/+),hMLH1(+) cell line, G2/M arrest was maintained for at least 12 days. There was little concomitant apoptosis, but this was enhanced when the hMLH1 protein was absent. This enhanced apoptosis was accompanied by a shorter duration of the G2/M arrest than in the hMLH1(+) cell line. Partial abrogation of G2/M arrest by caffeine enhanced apoptosis in both hMLH1(+) and hMLH1(-) cells. By contrast, in the p53(-/-) cell line, the G2/M arrest was terminated within 4 days. Termination of the G2/M arrest was accompanied by a high level of apoptosis detectable through poly(ADP-ribose)polymerase (PARP) cleavage, DNA fragmentation and by the appearance of cells with a DNA content <2N. The triggering of G2/M arrest was accompanied in the 3 cell lines by a transient phosphorylation of cdc-2, while the maintenance of the arrest in the p53(+/+) cell lines was accompanied by the overexpression of p53 and p21 proteins and, consequently, by the inhibition of cdc-2 kinase activity. These data indicate that: (i) CPT-11 induces long-term arrest in p53(+/+) cells and a short-term arrest followed by apoptosis in p53(-/-) cells; (ii) triggering of the arrest is p53 independent and is associated with a brief increase of phosphorylation of cdc-2, while the p53-dependent maintenance of G2/M arrest is associated with the inhibition of cdc-2 kinase activity by p21; and (iii) lack of hMLH1 protein enhances CPT-11-induced apoptosis. These results may be useful for designing rational therapies dependent on the p53 and mismatch-repair status in the tumor.
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PMID:Cellular effects of CPT-11 on colon carcinoma cells: dependence on p53 and hMLH1 status. 1220 84

Interactions between the topoisomerase I inhibitor irinotecan (CPT-11) and the platinum derivative oxaliplatin (L-OHP) were investigated in HT29 colon cancer cell line. Synergism was observed when cells were simultaneously exposed to drugs or when cells were first exposed to CPT-11. Flow cytometric studies showed a G(2)/M accumulation when cells were exposed to the simultaneous and CPT-11-->L-OHP combinations whereas a persistent S phase delay was observed when cells were first exposed to L-OHP. We characterised the cytotoxic effect by assessing the induction of apoptosis. Irinotecan induced substantial DEVDase activity and poly(ADP-ribose) polymerase cleavage while this activity was moderate and delayed after exposure to L-OHP. Combination experiments showed a sequence-dependent onset of apoptosis, the CPT-11-->L-OHP schedule being the earliest and the most effective; on the other hand the apoptotic signaling generated by CPT-11 was partly inhibited in the simultaneous combination and in the L-OHP-->CPT-11 sequence. Cell death studies using a dual staining technique showed a shift from apoptosis to necrosis when combining these drugs at high concentrations. Synergistic interactions observed using CPT-11 before L-OHP may be linked to an early apoptotic signaling while the L-OHP-induced S phase block could account for the observed additive effect in the reverse sequence. An additional phenomenon might work towards synergism for the simultaneous combination.
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PMID:Contribution of apoptosis in the cytotoxicity of the oxaliplatin-irinotecan combination in the HT29 human colon adenocarcinoma cell line. 1223 2

Irinotecan (CPT-11) is an anticancer agent for the treatment of colon cancer. CPT-11 can be considered as a prodrug, since it needs to be activated into the toxic drug SN-38 by the enzyme carboxylesterase. An approach to achieve tumour specific activation of CPT-11 is to transduce the cDNA encoding carboxylesterase into tumour cells. A secreted form of carboxylesterase may diffuse through a tumour mass and may activate CPT-11 extracellularly. This could enhance the antitumour efficacy by exerting a bystander effect on untransduced cells. In addition a secreted tumour-targeted form of carboxylesterase should prevent leakage of the enzyme from the site of the tumour into the circulation. We have constructed a secreted form of human liver carboxylesterase-2 by deletion of the cellular retention signal and by cloning the cDNA downstream of an Ig kappa leader sequence. The protein was secreted by transfected cells and showed both enzyme activity and efficient CPT-11 activation. To obtain a secreted, tumour-targeted form of carboxylesterase-2 the cDNA encoding the human scFv antibody C28 directed against the epithelial cell adhesion molecule EpCAM, was inserted between the leader sequence and carboxylesterase-2. This fusion protein showed CPT-11 activation and specific binding to EpCAM expressing cells. Importantly, in combination with CPT-11 both recombinant carboxylesterase proteins exerted strong antiproliferative effects on human colon cancer cells. They are, therefore, promising new tools for gene directed enzyme prodrug therapy approaches for the treatment of colon carcinoma with CPT-11.
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PMID:Secreted and tumour targeted human carboxylesterase for activation of irinotecan. 1223 77

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been reported to induce apoptosis in a variety of malignant cell lines, but it shows little or no toxicity in most normal cells. We examined the response of three human colon tumors to TRAIL alone and in combination with chemotherapy, using SCID mice engrafted with intact patient surgical specimens. These tumors, taken from fresh surgical specimens, contained the heterogeneous tumor cell population characteristic of patient tumors and showed differential sensitivity to TRAIL alone. We also investigated the effect of TRAIL in combination with chemotherapy, using one tumor that showed moderate sensitivity to TRAIL alone. Combining TRAIL with either 5-fluorouracil (5-FU) or CPT-11 (irinotecan hydrochloride) produced a greatly enhanced antitumor effect over that of either agent alone, with 50% of the animals achieving complete tumor regression with a combination of TRAIL and CPT-11. By histological analysis, tumors treated with TRAIL plus either 5-FU or CPT-11 were seen to consist mainly of connective tissue and fibrotic areas with only a few scattered tumor cells encapsulated in the connective tissue. Several markers were assessed to investigate the basis for the observed therapeutic effect, and significant induction of apoptosis was observed in tumors treated with curative combinations. Cytoplasmic and cell surface expression of the TRAIL receptors DR4 and DR5 was observed in this patient's tumor by immunohistochemistry. Tumors treated with CPT-11 showed increased membrane expression of DR5, suggesting that CPT-11 may increase sensitivity to TRAIL by up-regulation of DR5. These results obtained in a relevant preclinical model support the idea that the use of TRAIL in combination with either 5-FU or CPT-11 may be an effective strategy in controlling human colon cancer.
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PMID:Effects of tumor necrosis factor-related apoptosis-inducing ligand alone and in combination with chemotherapeutic agents on patients' colon tumors grown in SCID mice. 1238 41

The anti-metastatic efficacy of MMI-166, which is a selective matrix metalloproteinase (MMP) inhibitor, in combination with CPT-11 was examined using two metastasis models of human gastrointestinal cancer cells. In the liver metastasis model, C-IH human colon cancer cells were injected into the spleen of athymic BALB/c nude mice. Daily oral (p.o.) dosing of MMI-166 at 200 mg/kg starting 1 day after tumor inoculation led to a significantly prolonged survival effect by inhibiting liver metastasis of C-1H tumor cells. CPT-11 (5 or 20 mg/kg) was administered intraperitoneally (i.p.) three times on day 3, day 7 and day 11 and also improved the survival of tumor-inoculated mice compared with the vehicle control. When MMI-166 was combined with CPT-11, the anti-metastatic efficacy was significantly augmented. Moreover, long tumor-free survival was noted in two of eight mice that were given the combination therapy but not either MMI-166 or CPT-11 monotherapy. In the peritoneal dissemination model, TMK-1 human gastric cancer cells were injected i.p. into nude mice. While both MMI-166, administered daily p.o. from day 1 at 200 mg/kg, and CPT-11, administered intravenously (i.v.) three times, inhibited the tumor dissemination and growth, the combination therapy of MMI-166 plus CPT-11 showed a greater inhibitory effect than each monotherapy. A hematotoxicity study demonstrated that CPT-11 alone significantly decreased the number of white blood cells (WBC) and bone marrow cells (BMC) in the mice during treatment, while the daily administration of MMI-166 alone had no such effect. More importantly, the combination therapy of MMI-166 with CPT-11 did not augment the hematotoxicity caused by CPT-11. An in vitro cytotoxicity study showed that MMI-166 itself neither has direct cytotoxicity in C-1H and TMK-1 tumor cells, nor does it augment the cytotoxicity of SN-38, an active form of CPT-11. The findings indicate that the augmented anti-metastatic efficacy in combination treatment was not simply due to the augmentation of direct cytotoxic activity, but was rather an additive or synergistic effect of anti-metastatic activities with different mechanisms. In conclusion, we demonstrated that the anti-metastatic efficacy against C-1H colon cancer and TMK-1 gastric cancer were augmented by the combination therapy of MMI-166, an orally active MMP inhibitor, with CPT-11. However, the hematotoxicity caused by CPT-11 was not augmented in the combination with MMI-166. Thus, the combination therapy of MMI-166 and CPT-11 exhibited potent anti-metastatic efficacy without increased hematotoxicity. These results point to the clinical advantage of using MMI-166 in combination with CPT-11.
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PMID:Augmented anti-metastatic efficacy of a selective matrix metalloproteinase inhibitor, MMI-166, in combination with CPT-11. 1240 89


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