Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.3.1.21 (CPT)
4,580 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Irinotecan hydrochloride (CPT-11) is a topoisomerase I inhibitor with a broad antitumor spectrum. In the present study, we combined CPT-1 and mitoxantrone (MIT) with dexamethasone because the effect elicited by this combination was additive or better in a preclinical study. This study was performed to determine the efficacy and toxicities of this combination. Thirty-two patients were evaluable. CPT-11 combined with MIT achieved a complete remission in 11 patients (34.4%) and a partial remission in 9 patients (28.1%). The median follow-up period was 20 months. The 4-year survival rate was 31.8% (95% confidence intervals: 11.2-64.6%), and the 3-year event-free survival rate was 16.1% (95% confidence intervals: 8.2-24.6%). Grade 3 or higher hematological toxicity included neutropenia in 96.9%, anemia in 3.1%, and thrombocytopenia in 15.6%. Grades 1, 2, and 3 nonhematological toxicity included diarrhea in one patient, nausea/vomiting in five patients, and hematuria in one patient, respectively. CPT-11 combined with MIT was safe even for elderly patients and was effective even in patients who had received pretreatment with doxorubicin. In addition, this regimen can be used on an outpatient basis. This combination should be tested further to determine the optimum doses and administration schedule.
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PMID:Combination therapy with irinotecan (CPT-11), mitoxantrone, and dexamethasone in relapsed or refractory non-Hodgkin's lymphoma: a pilot study. 1152 67

Reverse transcription polymerase chain reaction (RT-PCR) single-strand conformation polymorphism analysis was used to detect topoisomerase I (top1) mutations in total RNA from 16 specimens that were excised during surgery from eight patients with non-small cell lung cancer (NSCLC) who had received preoperative chemotherapy consisting of irinotecan (CPT-11) and cisplatin. PCR single-strand conformation polymorphism and subsequent DNA sequencing analysis showed two nucleotide substitutions resulting in Trp736stop (TGG to TGA) and Gly737Ser (GGT to AGT) in one tumor specimen. The mutations were located near a site in top1 that was previously reported to harbor a mutation in the human lung cancer cell line PC7/CPT, which was selected for CPT resistance. These results demonstrate that mutations in top1 occur after chemotherapy with CPT-11 in NSCLC patients and suggest that development of resistance to CPT-11 in some patients may involve mutation of top1. However, the significance of top1 mutations to CPT resistance needs to be further investigated.
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PMID:Point mutations in the topoisomerase I gene in patients with non-small cell lung cancer treated with irinotecan. 1184 5

7-Ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (irinotecan, CPT-11) is a camptothecin prodrug that is metabolized by carboxylesterases (CE) to the active metabolite 7-ethyl-10-hydroxycamptothecin (SN-38), a topoisomerase I inhibitor. CPT-11 has shown encouraging antitumor activity against a broad spectrum of tumor types in early clinical trials, but hematopoietic and gastrointestinal toxicity limit its administration. To increase the therapeutic index of CPT-11 and to develop other prodrug analogues for enzyme/prodrug gene therapy applications, our laboratories propose to develop camptothecin prodrugs that will be activated by specific CEs. Specific analogues might then be predicted to be activated, for example, predominantly by human liver CE(hCE1), by human intestinal CE (hiCE), or in gene therapy approaches using a rabbit liver CE (rCE). This study describes a molecular modeling approach to relate the structure of rCE-activated camptothecin prodrugs with their biological activation. Comparative molecular field analysis, comparative molecular similarity index analysis, and docking studies were used to predict the biological activity of a 4-benzylpiperazine derivative of CPT-11 [7-ethyl-10-[4-(1-benzyl)-1-piperazino]carbonyloxycamptothecin (BP-CPT)] in U373MG glioma cell lines transfected with plasmids encoding rCE or hiCE. BP-CPT has been reported to be activated more efficiently than CPT-11 by a rat serum esterase activity; however, three-dimensional quantitative structure-activity relationship studies predicted that rCE would activate BP-CPT less efficiently than CPT-11. This was confirmed by both growth inhibition experiments and kinetic studies. The method is being used to design camptothecin prodrugs predicted to be activated by specific CEs.
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PMID:Activation of a camptothecin prodrug by specific carboxylesterases as predicted by quantitative structure-activity relationship and molecular docking studies. 1461 91

Small-cell lung cancer (SCLC) accounts for approximately 15% of all cases of lung cancer and is a particularly aggressive form of lung cancer characterised by a poor prognosis, rapid tumour growth, and early metastasis. Roughly, two-thirds of patients with SCLC present with extensive disease (ED) and one-third with limited disease (LD). Combination chemotherapy is the most effective treatment modality for SCLC, and several new agents, including carboplatin, ifosfamide, taxans, and topotecan, have been demonstrated to be active; however, there are no data on the survival benefit of these drugs. A CPT-11+ cisplatin regimen has shown improvement in overall survival over the global gold standard regimen, etoposide + cisplatin (Japanese Clinical Oncology Group: JCOG 9511), and three confirmatory randomised controlled trials are in progress to determine the reproducibility of the JCOG 9511 study. JCOG is evaluating the role of CPT-11 and a new triplet regimen containing CPT-11 in limited-stage SCLC. Strategies and the current protocols of the JCOG are presented and discussed. In the future, it will be essential to evaluate molecular target-based drugs for LD and ED SCLC with new standard combination chemotherapy regimens that include CPT-11.
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PMID:Progress in treatment of small-cell lung cancer: role of CPT-11. 1467 91

The CPT-11 trial was conducted to confirm the superiority of CDDP+CPT-11 (CPT-P) arm to CDDP+VDS (VDS-P) arm with regard to survival for patients with previously untreated advanced (stage IIIB/IV) non-small-cell lung cancer. However, the CPT-P arm did not show the survival benefit for patients with stage IIIB. The proportion of patients with stage IIIB treated by active radiation given as second-line treatment (second-line radiotherapy) after initial (first-line) treatment was 45 per cent in the CPT-P arm while 61 per cent in the VDS-P arm. This showed that not proving survival advantage in the CPT-P arm might be due to the benefits of second-line radiotherapy. We apply two causal models appeared in the companion paper to test and estimate the survival differences that would have been observed if all the patients had been received the same second-line radiotherapy. Based on several assumptions, we inferred that the CPT-P arm still would not have showed survival advantage if all the patients had been given identical second-line radiotherapy.
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PMID:Adjusting for differential proportions of second-line treatment in cancer clinical trials. Part II: an application in a clinical trial of unresectable non-small-cell lung cancer. 1521 99

To compare irinotecan (CPT-11)+gemcitabine vs CPT-11 alone as second-line treatment for patients with advanced non-small cell lung cancer (NSCLC) progressing after docetaxel-cisplatinum-based therapy. A total of 147 evaluable, pretreated patients, with NSCLC, received either gemcitabine (1000 mg m(-2), days 1 and 8)+CPT-11 (300 mg m(-2), day 8) (Group A, n=76) or CPT-11 (300 mg m(-2), day 1) (Group B, n=71), every 3 weeks. All patients were evaluable for response and toxicity. The objective response rate was 18.4% (95% CI: 9.71-27.14%) and 4.2% (95% CI: 0-8.90%) (P=0.009) for groups A and B, respectively. No significant differences between the two groups in terms of the median duration of response, time to tumour progression, overall survival and 1-year survival were observed. The CPT-11/gemcitabine regimen significantly improved the patients' quality of life ('general mood today' (P=0.014), 'coughing' (P=0.003) and 'intensity of symptoms' (P=0.034)) compared with CPT-11. More cycles had to be delayed (P=0.001) and required prophylactic growth factor support (P=0.001) in Group A than B. Three (3.9%) patients in Group A and eight (11.3%) in Group B developed febrile neutropenia (P=0.09); one patient died of sepsis in each group. Three additional (Group A, n=1; Group B, n=2) treatment-related deaths were observed. Grade 3-4 haematologic toxicity was comparable in the two groups except anaemia (P=0.03 in favour of CPT-11). Other nonhaematologic toxicities were mild and similar in the two groups. CPT-11+gemcitabine resulted in a higher response rate and better control of disease-related symptoms than CPT-11 alone, but without any improvement in the overall survival.
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PMID:Irinotecan plus gemcitabine vs irinotecan for the second-line treatment of patients with advanced non-small-cell lung cancer pretreated with docetaxel and cisplatin: a multicentre, randomised, phase II study. 1523 86

A 54-year-old man underwent abdominoperineal resection for rectal cancer. Adjuvant chemotherapy was not performed because of stage I cancer. Nine months after the operation, solitary liver metastasis, and elevated CEA and CA19-9, were found during the postoperative work-up. A combination chemotherapy of CPT-11 and UFT-E was performed before scheduled liver resection. 150 mg/m2 of CPT-11 was administered on days 1 and 15. 375 mg/m2/day of UFT-E was divided in half and administered on days 3-7, 10-14, 17-21, and 24-28 as one course of treatment. This regimen was repeated every 5 weeks. The patient had a grade 2 diarrhea and nentropenia during the treatment. Bowel obstruction was also observed after 5 courses of treatment, which required hospitalization. In addition, the liver metastasis had disappeared. There was no evidence of recurrence after 8 months of chemotherapy. It was suggested that CPT-11+UFT-E combination chemotherapy was effective for advanced colorectal cancer.
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PMID:[Case report--Complete response of liver metastasis of rectal cancer after combination chemotherapy of CPT-11 + UFT-E]. 1555 88

Degradable starch microspheres (DSMs) provide transient occlusion of small arteries and are thought to improve the therapeutic effect of anticancer drugs. Irinotecan (CPT-11) is one of the most effective anticancer agents. We herein report cases with liver metastases treated with transarterial chemoembolization with DSM, CPT-11, and mitomycin-C (DSM-CPT therapy). Five patients underwent DSM-CPT therapy for liver metastases that originated from colorectal cancer for four and gastric cancer for one. They all lack indication for surgery. They were all male with an age range of 42-78 years (mean, 55.2 years). Three of them had pretreatment histories with 5-fluorouracil or related agents, and four of them had combined systemic or local chemotherapy at the period. Required doses for stasis of whole blood flow of hepatic artery of DSMs were used with CPT-11 and mitomycin-C. After one to six injections, four patients had a partial response and the disease progressed in one patient with gastric cancer origin. Two of the partial response patients underwent surgery after 2 months of the partial response period. Carcinoembryonic antigen and CA19-9 levels in partial response patients decreased to 16.1% and 19.3% of the level before treatment, respectively. DSM-CPT therapy can be a potential therapy for liver metastases.
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PMID:Transarterial chemoembolization with degradable starch microspheres, irinotecan, and mitomycin-C in patients with liver metastases. 1645 58

It has been shown that the human acute lymphoblastic leukemia (ALL) T cell line (RPMI 8402) selected with irinotecan (CPT-11) is transformed to a multidrug resistant (MDR) phenotype (CPT-K5) with cross-resistance to mitoxantrone (MX). Since MX is a well-documented substrate for the efflux transporter breast cancer resistant protein (BCRP/ABCG2), we assessed the contribution of drug efflux to MX resistance in CPT-K5 cells. Our results demonstrate that CPT-K5 cells had markedly higher expression levels of BCRP, negligible expression of MRP2 and P-gp, and lower intracellular retention of MX as compared to RPMI 8402 cells. Surprisingly, MX resistance in CPT-K5 cells was not reversed by the BCRP chemical inhibitor, novobiocin (NOV), or gene-specific siRNA, although intracellular MX concentrations were significantly increased when BCRP was functionally knocked down. These results suggest that up-regulation of BCRP plays a minimal role in conferring MX resistance to CPT-K5 cells, highlighting the existence of multiple, redundant mechanisms of drug resistance. The current results support the concept of "multifactorial multidrug resistance", a recently-described phenomenon that ascribes multidrug resistance to many possible cellular mechanisms, not only by efflux drug transporters.
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PMID:Inhibition of efflux transporter ABCG2/BCRP does not restore mitoxantrone sensitivity in irinotecan-selected human leukemia CPT-K5 cells: evidence for multifactorial multidrug resistance. 1684 60

We treated two patients in whom irinotecan (CPT-11)+cisplatin (CDDP) and irradiation showed efficacy against brain metastases of gastric cancer. CPT-11 and CDDP were administered on days 1 and 15 of a 28-day cycle at 60 mg/m(2) and 30 mg/m(2), respectively. The first patient was a 63-year-old man,who complained of headache and weakness. In March 2003, he was diagnosed as having Stage IV gastric cancer with peritoneal dissemination (T3, Nx, P1) and underwent total gastrectomy with D1 dissection. Chemotherapy with S-1 was continued after surgery. Two years and two months later, a metastatic tumor was found in the upper lobe of the right lung. The protocol was changed to S-1+CDDP, but progression of his disease occurred. The weekly paclitaxel (PTX) therapy was tried instead. Seven months later, he developed headache and weakness, and multiple brain metastases were diagnosed by CT scanning. We performed total brain irradiation (30 Gy) and started CPT-11+CDDP therapy, which was continued on a fortnightly basis at 60 mg/m(2) and 30 mg/m(2), respectively. The brain metastases regressed (PR), and this therapy led to a marked improvement in his quality of life. The second patient was a 78-year-old man, who complained of weakness of the lower extremities and dizziness. In November 2003, he was diagnosed as having stage IB gastric cancer (T2 (ss), N0, P0), and underwent total gastrectomy and splenectomy with D2 dissection. One year and four months later, local recurrence at the anastomosis was detected, as well as a metastatic tumor in the right lung. S-1, S-1+CDDP, and weekly PTX therapy were all tried. One year later, the patient was admitted with weakness and dizziness,and brain metastases were detected by CT scanning. We then performed Cyber Knife treatment and administered CPT-11+CDDP. As a result, his brain metastases partially regressed (PR).
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PMID:[Irinotecan+cisplatin and irradiation are effective for brain metastases of gastric cancer--two case reports]. 1763 47


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