甲基莲心碱对长春新碱抑制人胃癌细胞增殖作用的影响

目的：观察甲基莲心碱（Nef）在体外对长春新碱抑制人胃癌细胞增殖及诱导人胃癌细胞凋亡的影响。方法：采用MTT比色法、软琼脂克隆形成法检测药物的细胞毒性作用,并用流式细胞术、AO/EB荧光双染色法测定Nef对长春新碱诱导人胃癌细胞凋亡的影响。结果：2.5、5、10μmol/LNef能增强长春新碱对人胃癌细胞（SGC7901）增殖的抑制作用;10μmol/LNef能增强长春新碱（0.1、0.5、2、4μg/ml）诱导SGC7901细胞凋亡。结论：甲基莲心碱能增强长春新碱抑制人胃癌细胞增殖及诱导人胃癌细胞凋亡,为一种低毒高效的化疗增敏剂。     

Chemotherapy-induced peripheral neuropathy

The induction of peripheral neuropathy is a common factor in limiting therapy with chemotherapeutic drugs. Little is known about the mechanisms responsible for the development of neuropathy. Depending on the substance used, a pure sensory and painful neuropathy (with cisplatin, oxaliplatin, carboplatin) or a mixed sensorimotor neuropathy with or without involvement of the autonomic nervous system (with vincristine, taxol, suramin) can ensue. Neurotoxicity depends on the total cumulative dose and the type of drug used. In individual cases neuropathy can evolve even after a single drug application. A general predisposition for developing a chemotherapy-induced neuropathy has been observed in nerves previously damaged by diabetes mellitus, alcohol or inherited neuropathy. The recovery from symptoms is often incomplete and a long period of regeneration is required to restore function. Up to now, no drug is available to reliably prevent or cure chemotherapy-induced neuropathy. Received: 15 November 2000, Received in revised form: 12 April 2001, Accepted: 19 April 2001     

The influence of recombinant human insulin-like growth factor-I (rhIGF-I) on cell growth and cytotoxicity of drugs in childhood rhabdomyosarcoma cell lines and xenograft models

Purpose: Recombinant human insulin-like growth factor I (rhIGF-I) has been reported to ameliorate vincristine-induced neuropathy, the dose-limiting side effect of this antimitotic anticancer drug. However, rhIGF-I also might have adverse effects, as has been shown in vitro, where it stimulates growth of cancer cells and protects them from cytotoxicity of anticancer drugs. The influence of rhIGF-I on the cytotoxicity of vincristine has not yet been studied. Furthermore, studies performed have been done under serum-free conditions, which are far from physiological. Methods: We studied the influence of rhIGF-I on the growth of two rhabdomyosarcoma cell lines (Rh30 and Rh1) and on the antitumor effects of vincristine, cisplatin, etoposide, doxorubicin, and topotecan under serum-free and serum-containing conditions. To extend the in vitro data, we grew Rh30 cells as xenografts in mice and determined the effects of vincristine, rhIGF-I or their combination on tumor growth. Results: In vitro, both cell lines demonstrated a functional type I IGF receptor, as shown by the rapid activation of ribosomal p70 S6 kinase after stimulation with rhIGF-I. Under serum-free conditions, rhIGF-I stimulated growth of both cell lines. Exposure to cytotoxic drugs with and without rhIGF-I resulted in higher cell numbers in cultures exposed to rhIGF-I. However, relative to the appropriate control, fractional growth inhibition and or cell kill of the cytotoxic drugs was identical with and without rhIGF-I. Under serum-containing conditions, rhIGF-I had no effect on cell growth or drug cytotoxicity. In vivo we did not find a significant influence of rhIGF-I on HxRh30 cell growth, or on the antitumor activity of vincristine. Conclusions: These studies show that rhIGF-I has no adverse effects on human rhabdomyosarcoma growth or on the antitumor effect of cytotoxic drugs under serum-containing conditions in vitro or in tumor-bearing mice. Potentially, therefore, rhIGF-I may ameliorate vincristine-induced neuropathy without adversely influencing tumor growth or vincristine cytotoxicity in children. Received: 12 February 1999 / Accepted: 21 June 1999     

Modulation of P-glycoprotein-mediated multidrug resistance in K562 leukemic cells by indole-3-carbinol

Resistance to chemotherapeutic drugs is one of the major problems in the treatment of cancer. P-glycoprotein (P-gp) encoded by the mdr gene is a highly conserved protein, acts as a multidrug transporter, and has a major role in multiple drug resistance (MDR). Targeting of P-gp by naturally occurring compounds is an effective strategy to overcome MDR. Indole-3-carbinol (I3C), a glucosinolates present in cruciferous vegetables, is a promising chemopreventive agent as it is reported to possess antimutagenic, antitumorigenic, and antiestrogenic properties in experimental studies. In the present investigation, the potential of I3C to modulate P-gp expression was evaluated in vinblastine (VBL)-resistant K562 human leukemic cells. The resistant K562 cells (K562/R10) were found to be cross-resistant to vincristine (VCR), doxorubicin (DXR), and other antineoplastic agents. I3C at a nontoxic dose (10 x 10(-3) M) enhanced the cytotoxic effects of VBL time dependently in VBL-resistant human leukemia (K562/R10) cells but had no effect on parent-sensitive cells (K562/S). The Western blot analysis of K 562/R 10 cells showed that I3C downregulates the induced levels of P-gp in resistant cells near to normal levels. The quantitation of immunocytochemically stained K562/R10 cells showed 24%, 48%, and 80% decrease in the levels of P-gp by I3C for 24, 48, and 72 h of incubation. The above features thus indicate that I3C could be used as a novel modulator of P-gp-mediated multidrug resistance in vitro and may be effective as a dietary adjuvant in the treatment of MDR cancers.     

M-VCA方案治疗晚期鼻咽癌35例疗效分析

目的 探讨Ｍ－ＶＣＡ方案治疗晚期鼻咽癌的疗效及毒副反应,方法：对３５例晚期鼻咽癌患者（初治诱导化疗者１１例,复发或转移者２４例）采用ＭＴＸ＋ＶＣＲ＋ＤＤＰ＋ＡＤＭ联合化疗方案治疗。结果 评定其化疗２疗程后的客观疗效,总有效率为７５．５１％,无ＣＲ病例,其中初治肿瘤有效率达１００％,复发者为６６．６７％,远处转移总有效率为７０．０％,肺转移疗效最好（８８．８９％）,主要毒副反应是脱发,轻到中度的骨髓     

脂质体阿霉素逆转肿瘤多药耐药的活性和机制研究

目的 探讨脂质体阿霉素( PLD)逆转肿瘤多药耐药(MDR)的活性及其逆转机制.方法 以噻唑蓝(MTT)方法检测PLD对多药耐药肿瘤细胞MCF-7/ADR及KBv200的耐药逆转活性.结果 PLD在体内具有较强的逆转活性,逆转活性大于公认的强逆转剂维拉帕米的活性;在5.0μmol/L浓度下使多药耐药细胞KBv200对长春新碱的敏感性增加了45倍.PLD浓度依赖性增加(0、2.5、5.0、10 μmol/L)KBv200细胞内的罗丹明蓄积.PLD的心脏毒性、骨髓抑制以及脱发等不良反应显著降低.结论 脂质体阿霉素具有较强的逆转MDR的活性,主要通过持续向肿瘤组织聚集,肿瘤局部药物浓度升高,抗肿瘤的活性增强.     

长春新碱载体红细胞体内代谢分布的初步研究

目的：初步探讨长春新碱载体红细胞在小鼠体内的分布代谢情况。方法i昆明种小鼠腋窝皮下接种S180肉瘤细胞建立荷瘤小鼠模型,将荷瘤小鼠随机分为长春新碱、长春新碱载药红细胞2组,经尾静脉分别注射长春新碱200ug及长春新碱载药红细胞（浓度1cg／L）。注射后0、1、2、3、4、24、48及72h取小鼠血液、肝脏及肿瘤组织,用高效液相色谱法测定其中药物浓度,计算半衰期。结果：长春新碱进入体内后血浆浓度迅速增高,其代谢速率也很快,48h后完全测不出,半衰期1．53h。长春新碱载药红细胞在血浆中浓度稳定而持久,72h仍可测出,药物半衰期达4．1h,是前者的2．68倍。载药红细胞在肝脏及肿瘤中的浓度和稳定性均高于游离药物,且随着时间延长,这种优势越来越大。结论：载药红细胞延缓药物释放,延长药物作用时间;增强了药物向肝脏及肿瘤的靶向聚集,减少不良反应。为临床肿瘤治疗提供新思路和可行方法。     

长春新碱对激素依赖型肾病综合征的治疗

目的：目前对于激素依赖型肾病综合征的治疗仍较困难,我们回顾性地评价了长春新碱对用过环磷酰胺治疗后而仍有复发的激素依赖型肾病综合征患儿的治疗效果。方法：14例口服过一个疗程以上环磷酰胺而仍有复发的激素依赖型肾病综合征患儿接受了长春新碱治疗。长春新碱的用法为每周静脉注射1次,连用4周,然后每月1次,连用4月,每次剂量为1~1.5 mg/m2。结果：13例完成了长春新碱的整个疗程。正处于肾病复发期的8例患儿,6例(75%)完全缓解,蛋白尿在用长春新碱治疗2~3剂后消失。在疗程结束后对处于肾病缓解状态的12例患儿随访,发现4例(33.3%)未再复发,持续保持缓解9~40月(中位数为13.5月);半年内的肾病复发次数由治疗前的1.67次降至0.67次(P<0.05);8例再复发者,7例再次注射长春新碱(1 mg/m2)1~2剂后蛋白尿均消失。除用1.5 mg/m2剂量时腹痛较显著外患儿未出现其他明显副作用。结论：长春新碱能诱导激素依赖型肾病综合征复发患儿的完全缓解,还有可能降低复发频率。对于再复发患儿,少数几次长春新碱的使用可能优于口服一个疗程的泼尼松龙或环孢素。[中国当代儿科杂志,2005,7(6):495-498]     

Role of xenobiotic efflux transporters in resistance to vincristine.

This study characterized interactions between efflux transporters (P-glycoprotein (MDR1) and multidrug resistance associated proteins (MRPs1-3)) and vincristine (VCR), using cell lines with differential transporter expression, and studied effects of P-glycoprotein inhibition on VCR transport and toxicity. Caco2 (express MDR1, MRPs 1-3), LS174T (express MDR1, MRPs 1, 3), and A549 (express MRPs 1-3) cells were used. To study VCR transport (effective permeability, P(eff)), VCR (1-500 nM) was added to the donor chambers of permeable supports containing Caco2 monolayers, and receiving chamber concentrations were measured. Cytotoxicity experiments were conducted with escalating concentrations of VCR in all cell lines. To determine the contribution of MDR1, experiments were also conducted with LY335979, a specific MDR1 inhibitor. VCR P(eff) was 2 x 10(-6)cm/s in Caco2 cells. LY335979 increased P(eff) in a dose dependent manner (up to 7-fold with 1 microM LY335979) in Caco2 cells. Caco2 and LS174T cell viability decreased significantly when co-incubated with both VCR and LY335979 (1 microM) (P<0.05), however this was not observed in A549 cells. In summary, MDR1 plays an important role in VCR efflux; MDR1 inhibition increased VCR P(eff) in Caco2 cells, and increased VCR cytotoxicity in Caco2 and LS174T cells (both express MDR1), but not A549 cells (minimal MDR1 expression). Inhibition of MDR1 may be a viable strategy to overcome VCR resistance in tumors expressing MDR1, however the presence of other efflux transporters should also be considered, as this will influence the success of such strategies.     

Vincristine-induced recurrent laryngeal nerve paralysis in children

Stridor developed in 2 children during vincristine therapy for malignancies. Indirect laryngoscopy revealed left vocal cord paralyse in both patients. One child had generalized neurotoxicity from vincristine including hypotonia, decreased gastrointestinal motility, and painful parasthesias while laryngeal nerve paralysis was the only neurotoxic manifestation in the other patient. Stridor resolved in both patients after discontinuing or decreasing the dose of vincristine. Visualization of the airway not only confirms the diagnosis, but also rules out treatable causes of stridor in the febrile, immunocompromised patient.Supported by the American Lebanese Syrian Associated Charities