Eicosanoid-mediated Cl− secretion induced by the antitumor drug,irinotecan (CPT-11), in the rat colon

Irinotecan (CPT-11) is active against a broad range of human cancer. One of the side-effects of irinotecan is a strong diarrhoea. In order to investigate the mechanism underlying this diarrhoea, the effect of irinotecan on anion secretion across the isolated rat distal colon was studied. Irinotecan caused a concentration-dependent increase in short-circuit current (Isc). The increase in Isc was completely dependent on the presence of Cl^– ions and was supressed by furosemide and the Cl^– channel blocker NPPB (5-nitro-2-(3-phenylpropylamino)-benzoate), indicating that it is caused by a Cl^– secretion. The secretory response was inhibited by indomethacin, 1-benzylimidazole, a thromboxane synthase inhibitor, and SK&F 88046 ((N,Nbis-[7-(3-Chlorobenzeneaminosulfonyl)-1,2,3,4-tetrahydroisoquinolyl)disulfonylimide), a thromboxane A₂ receptor blocker. In isolated crypts irinotecan had no effect on the membrane potential. Consequently, the secretion induced by irinotecan is an indirect one, caused by the stimulation of eicosanoid production, e.g. thromboxane A₂, in the subepithelial tissue.     

In vitro schedule-dependent interaction between paclitaxel and SN-38 (the active metabolite of irinotecan) in human carcinoma cell lines

Paclitaxel and irinotecan are important new anticancer agents. The combination of these two agents has been considered for use against a variety of advanced solid tumors. Since the schedule-dependent effects of this combination may be crucial to its use, we studied the interaction of paclitaxel and SN-38 (the active metabolite of irinotecan) in various schedules in four human cancer cell lines in culture. Cell growth inhibition after 5 days was determined using an MTT assay. The effects of drug combinations at the IC₈₀ level were analyzed by the isobologram method. Simultaneous exposure to paclitaxel and SN-38 for 24 h produced antagonistic (subadditive and protective) effects in the human lung cancer cell line A549, the breast cancer cell line MCF7, and the colon cancer cell line WiDr, and produced additive effects in the ovarian cancer cell line PA1. Sequential exposure to paclitaxel for 24 h followed by SN-38 for 24 h, and the reverse sequence, produced additive effects in all four cell lines. These findings suggest that sequential administration, not simultaneous administration, may be the appropriate schedule for the therapeutic combination of paclitaxel and irinotecan. Continued preclinical and clinical studies should provide further insights and assist in determining the optimal schedule for this combination in clinical use. Received: 25 February 1997 / Accepted: 6 November 1997     

伊立替康治疗结直肠癌相关胆碱能综合征89例

目的:观察和分析伊立替康治疗结直肠癌相关胆碱能综合征的发生情况.方法:应用2种FOLFIRI方案治疗转移性结直肠癌患者89例,观察和记录胆碱能综合征发生情况,并将其与患者临床资料、其他不良反应和所应用的治疗方案进行相关性分析.结果:53例(59.6%)患者发生胆碱能综合征,中位发生时间为伊立替康开始滴注后150min(30min-25h),绝大多数在用药后24h内逐渐消退,预防性应用阿托品可以有效预防胆碱能综合征发生;≥60岁老年患者胆碱能综合征明显高发(75.9%vs51.7%,P=0.029),未发现其与性别、ECOG评分等临床特征有关;出现胆碱能综合征患者迟发性腹泻有减少趋势(52.8%vs34.0%,P=0.077),未发现胆碱能综合征与其他不良反应相关;采用高剂量氟尿嘧啶治疗方案患者黏膜炎明显高发(50.0%vs27.5%,P=0.029).结论:伊立替康相关胆碱能综合征高发,应引起临床医生重视;胆碱能综合征对后续可能发生的迟发性腹泻和/或骨髓抑制无预测作用.     

The antioxidants,vitamin A and E but not vitamin C and melatonin enhance the proapoptotic effects of irinotecan in cancer cells in vitro

Irinotecan is one of the camptothecin analog which has been shown to have a broad spectrum of antitumor activities against various malignancies. The aim of this study was to evaluate the effect of vitamin A, C, E and melatonin on proapoptotic activity of irinotecan in human cancer cells in vitro. We observed that irinotecan induced apoptosis in all types of analyzed cell lines when used as a single agent. Combination of selected antioxidants with various doses of irinotecan (7.5–60 μM) resulted in significant increase in apoptotic cell death in A549 and HT29 cancer cell lines. The highest killing efficiency was observed after co-incubation of the cells with irinotecan and vitamin A (10 μM), or vitamin E (25 μM), respectively. The addition of vitamin C and melatonin to irinotecan treatment did not promote increase in killing of cancer cells. Our results indicate that some antioxidants can enhance the proapoptoic activity (properties) of irinotecan in human cancer cells in vitro. These findings may be supportive for the optimization of therapeutic efficacy of irinotecan treatment.     

Locoregional therapy and systemic cetuximab to treat colorectal liver metastases

AIM: To investigate efficacy and safety of second-line treatment with irinotecan-loaded drug-eluting beads (DEBIRI) and cetuximab (DEBIRITUX) of unresectable colorectal liver metastases.METHODS: Patients with the following characteristics were included in the study: unresectable hepatic metastases from colorectal carcinoma (CRC-LM), progression after first line chemotherapy (any type of chemotherapeutic drug and combination was allowed), second line treatment (mandatory), which included for each patient (unregarding the KRas status) two cycles of DEBIRI (using 100-300 μm beads loaded with irinotecan at a total dose 200 mg) followed by 12 cycles of cetuximab that was administered weekly at a first dose of 400 mg/m² and then 250 mg/m²; good performance status (0-2) and liver functionality (alanine aminotransferase and gamma-glutamyl transferase not exceeding three times the upper limit of normal, total bilirubin not exceeding 2.5 mg/mL). Data were collected retrospectively and included: tumor response (evaluated monthly for 6 mo then every 3 mo), overall response rate (ORR), KRas status, type and intensity of adverse events (G according to the Common Terminology Criteria for Adverse Events v3.0, CTCAE), overall survival (OS) and progression free survival (PFS).RESULTS: Forty consecutive cases of CRC hepatic metastases were included in the study. Median duration of DEBIRITUX was 4.4 mo (range, 4.0-6.5). Sixteen patients (40%) received the planned 2 cycles of DEBIRI and an average of 10 cetuximab cycles. ORR of the whole sample was 50%, in particular 4 patients were complete responders (10%) and 16 (40%) partial responders. The most observed side effects (G2) were: post-embolization syndrome (30%), diarrhea (25%), skin rushes (38%) and asthenia (35%). The retrospective evaluation of KRas status (24 wild type, 16 mutated) showed that the group of patients with wild type KRas had ORR significantly higher than mutant KRas. Median follow-up was 29 mo (8-48 range); median PFS was 9.8 mo and OS was 20.4 mo. Future randomized trials are required in this setting to establish a role for DEBIRITUX compared with systemic chemotherapy.CONCLUSION: DEBIRITUX seems to be efficacious after first line chemotherapy for the treatment of unresectable CRC-LM.     

高效液相色谱法测定血中伊立替康及活性代谢物SN-38浓度

目的：建立高效液相色谱法同时测定结直肠癌患者血中的伊立替康（CPT-11）及其活性代谢物7-乙基-10-羟基喜树碱（SN-38）的浓度,并对我院基因型指导给药方案进行评价。方法：以2μg·mL-110-羟基喜树碱作为内标,先用100μL 10%高氯酸沉淀蛋白,再用50μL 10%高氯酸酸化血浆。采用Agilent ZORBAX Eclipse C8色谱柱（4.6 mm×150 mm,5μm）对CPT-11和SN-38进行分离;以0.05 mol·L-1的磷酸二氢钠-乙腈-三乙胺（75∶25∶0.1,v∶v,磷酸调pH 3.0）为流动相;荧光检测波长：激发波长380 nm,发射波长550 nm。结果：人血浆中CPT-11和SN-38线性范围均为3~1000 ng·mL-1,定量下限为3 ng·mL-1;准确度分别是98.5%和100.0%;回收率分别是83.8%和84.3%。结论：本方法可靠、简便、快速,可为伊立替康个体化给药提供参考。     

希罗达联合多西他赛或伊立替康治疗晚期胃癌的临床对照研究

目的 比较多西他赛与伊立替康分别联合希罗迭治疗晚期胃癌的近期疗效和不良反应. 方法 65例患者随机分为两组,A组33例应用多西他赛联合希罗达,B组32例联合应用多西他赛、伊立替康和联合希罗达,均化疗2周期以上. 结果 A组有效18例(54.54%),中位无进展生存期(PFS)为6.1个月;B组分别为17例(53.13%)和6.2个月(均P>0.05).A组贫血较重,B组腹泻较重. 结论 两种方案对晚期胃癌患者均有较好疗效且疗效相当,不良反应可以耐受.     

伊立替康不良反应与患者个体差异相关性的研究进展

伊立替康是治疗胃肠道肿瘤和小细胞肺癌的常用化疗药物,其最常见的不良反应为迟发性腹泻和中性粒细胞减少。不良反应的发生与遗传因素和非遗传因素有关。遗传因素涉及羧酸酯酶、肝脏尿苷二磷酸葡萄糖醛酸转移酶1A和细胞色素P4503A4等多种酶与转运体的基因多态性。患者的年龄、吸烟、合并用药等非遗传因素也可影响机体对伊立替康的敏感性和药物在体内的代谢过程。针对不同基因型患者制定伊立替康的个体化治疗方案,有助于提高临床疗效并降低不良反应发生率。     

伊立替康相关腹泻及粒细胞缺乏致死 亡简

1 例62 岁结肠癌男性患者,接受伊立替康80 mg 静脉滴注d1、d8 化疗.化疗后反复腹泻11 d,化疗第13 天腹泻加重伴发热,急诊入院.查血常规示WBC 0.34×109·L-1,NEUT 5.94%,L 85.34%,RBC 3.84×1012·L-1,Hb 114.0 g·L-1,PLT 33×109·L-1.BUN 13.71 mmol·L-1,Scr 291 μmol·L-1.给予头孢匹罗抗感染,重组人粒细胞集落刺激因子升白细胞,免疫调节,止泻、护肾、补液等对症治疗,入院第2 天出现感染性休克,给予抗休克等治疗.第3 天出现深度昏迷,血压难以维持.最终因循环、呼吸衰竭死亡.