CAT方案治疗难治性急性髓系白血病的临床观察

目的：初步观察CAT(环磷酰胺、阿糖胞苷、拓扑替康)方案对难治性急性髓系白血病(AML)的近期临床疗效并评价此方案的不良副作用。方法：选择8例难治性AML(原发难治性AML3例，AML伴多系形态发育异常，此前有MDS病史患者3例，慢性粒细胞白血病AML变2例)．应用CAT方案治疗，其中4例治疗1疗程，其余4例治疗2疗程。结果：1例在骨髓抑制期死于感染性休克．可评价疗效7例，1例达完全缓解(CR)，3例达部分缓解(PR)，1例CML急变患者经2疗程后回到慢性期，总有效率71．4％(5/7例)，中位生存期为6．5(0．3—22^ )个月。主要不良副作用为骨髓抑制。结论：CAT方案为高危MDS、加速／急变期CML和继发于MDS的AML患者的一个有效且毒性可耐受的治疗新方案。     

拓扑替康联合顺铂治疗小细胞肺癌的临床研究

 目的　评价拓扑替康联合顺铂治疗小细胞肺癌 (SCLC)的疗效及安全性。方法　经病理组织学或细胞学确诊的 19例 ,用药方法为拓扑替康 (Topotecan ,TPT) 1.0mg/ (m2 ·d) ,静滴 30分钟 ,连用 5天 ;顺铂 (Cisplatin ,DDP) 30mg/m2 静滴 ,连用 3天 ,每 3周一疗程。治疗 2疗程评价疗效。结果　 19例可评价病人。总有效率为 4 7.6 % ,对初治及复治SCLC的有效率分别为 6 6 .7%、38.5 %。主要毒副反应为骨髓抑制。Ⅲ～Ⅳ度中性粒细胞减少及血小板减少的发生率分别为 5 2 .6 %、4 2 .1%。贫血发生率为6 3.5 % ,其中 2 6 .3%为中重度贫血。非血液学毒性较轻 ,一般可耐受。结论　拓扑替康联合顺铂为治疗SCLC的有效化疗方案 ,特别对复发的病例疗效较好。主要毒性为骨髓抑制 ,用药时应予足够重视。     

In vitro and in vivo interaction between cisplatin and topotecan in ovarian carcinoma systems

Topotecan, a camptothecin analogue, is a␣specific inhibitor of topoisomerase I approved for use in the treatment of patients with refractory ovarian carcinoma. The drug's mechanism of action suggests a potential efficacy of drug combinations incorporating DNA-damaging agents. In an attempt better to define a␣rational basis for drug combination we examined the effect of topotecan on the cytotoxicity and antitumor activity of cisplatin in an ovarian carcinoma system growing in vitro and in vivo as a tumor xenograft. The in vitro cell system included a cisplatin-sensitive cell line, IGROV-1, and a cisplatin-resistant subline, IGROV-1/Pt0.5, which is characterized by p53 mutation and loss of normal function of the wild-type gene of the parental cell line. This cell system was chosen since the cell sensitivity to DNA-damaging agents appears to be dependent on p53 gene status. Cytotoxicity was assessed by the growth inhibition assay using different schedules: (a) a 1-h period of cisplatin exposure followed by a 24-h topotecan treatment and (b) a 1-h period of simultaneous exposure to cisplatin and topotecan. In the case of the sequential schedule, an additive interaction was observed in IGROV-1 and IGROV-1/Pt0.5 cells. When the simultaneous schedule was used, a synergistic interaction, more evident for the cisplatin-sensitive cells, was found. On the basis of these observations at a cellular level, the effect of concomitant administration of the two drugs (i.e., the most favorable schedule) was studied in the IGROV-1 tumor xenograft, which is moderately responsive to cisplatin and topotecan. Suboptimal doses of each drug (with a low dose of topotecan, 5.1 mg/kg) achieved an antitumor effect comparable with or superior to that of the optimal dose of a single treatment (tumor weight inhibition, 60%), thus indicating a␣pharmacological advantage of the combination over the single treatment. However, an increase in the topotecan dose (7.1 mg/kg) was associated with an evident increase in the toxicity of the combination, thereby suggesting that the drug interaction was not tumor-specific. Although the molecular basis of the drug interaction is not clear, it is likely that inhibition of topoisomerase I affects the ability of cells to repair cisplatin adducts. Such findings may have pharmacological implications since they suggest the potential clinical interest of topoisomerase I inhibitors in combination with cisplatin. Received: 14 June 1997 / Accepted: 18 September 1997     

TP与NP方案治疗晚期非小细胞肺癌的疗效比较

目的 :观察盐酸拓扑替康 +顺铂 (TP方案 )与重酒石酸长春瑞滨 (诺维本 ) +顺铂 (NP方案 )分别治疗晚期非小细胞肺癌(NSCLC)的临床疗效和不良反应。方法 :将50例NSCLC患者随机分为TP方案组 (21例 )和NP方案组 (29例 )。治疗周期均为21d ,2个治疗周期后评价疗效。结果 :TP、NP方案组有效率分别为52.4 %、51.7 % ,中位生存期分别为9.2mo、8 6mo ,均无显著性差异 (P>0.05)。NP方案组不良反应程度及发生率均高于TP方案组 ,但两组比较均无显著性差异 (P>0.05)。结论 :2种方案临床疗效相近 ,不良反应相似 ,耐受性均较好。     

MRP3基因参与卵巢癌细胞拓扑替康耐药机制形成的研究

目的:分析人卵巢癌SKOV3/TPT多药耐药的分子机制,寻找可能参与拓扑替康(TPT)耐药机制的新基因。方法:采用大剂量间歇诱导法,对SKOV3细胞株用TPT反复冲击诱导培养,获得稳定的SKOV3/TPT;利用Affymetrix U133A基因表达谱芯片,比较SKOV3及SKOV3/TPT细胞的基因表达;从中选择高表达的MRP3基因进行RT-PCR验证。再将MRP3反义及正义寡核苷酸片段分别用脂质体转染进耐药细胞,用MTT法、流式细胞仪及半定量RT-PCR检测体外转染后细胞内TPT的荧光强度、耐药指数及MRP3 mRNA表达的改变。结果:基因芯片检测发现,有7个差异表达基因可能参与了SKOV3/TPT细胞的耐药,其中4个基因被上调,3个基因被下调,MRP3为上调最明显的基因。MRP3反义寡核苷酸转染SKOV3/TPT细胞后,可明显降低细胞内TPT的浓度及耐药指数(P<0.05),细胞内MRP3 mRNA的表达较未转染细胞下降了60.16%(P<0.05)。结论:SKOV3/TPT细胞耐药表型的形成涉及多个基因表达的改变。MRP3的高表达导致细胞内药物浓度降低,可能是卵巢癌细胞对TPT耐药的主要原因。     

荧光分光光度法测定注射用盐酸拓普替康的含量

目的:建立注射用盐酸拓普替康的荧光光度测定法.方法:以水为溶剂,采用荧光分光光度法测定注射用盐酸拓普替康的含量,测定波长为ex-380.8nm,em=521.6nm.结果:平均回收率99.81%,RSD为0.87%,线性范围为0.16～1.6μg·ml-1.结论:该方法简便,准确,适用于注射用盐酸拓普替康的含量测定.     

Topotecan induces hepatocellular injury via ASCT2 mediated oxidative stress

BackgroundTopotecan is an anti-cancer chemotherapy drug with common side effects, including hepatotoxicity. In this study, we aim to investigate the mechanisms of topotecan-induced hepatocellular injury beyond conventional DNA damage.Materials and methodsMethyl Thiazolyl Tetrazolium (MTT) assay was used to detect the inhibitory effect of topotecan on cell proliferation. Western blot was used to detect protein expression. Flow cytometry assay was performed to determine apoptosis rate under topotecan treatment. ASCT2 overexpression was addressed using adenovirus vector. qRT-PCR and western blot assay were used to detect the expression of ASCT2. Glutamine uptake, intracellular glutathione (GSH) and reactive oxygen species (ROS) level were detected by glutamine detection kit, GSH detection kit and ROS detection kit respectively.ResultsMTT results showed that topotecan had an inhibitory effect on cell proliferation and induced apoptosis in both L02 and HepG2 cell lines. Topotecan inhibited the expression of glutamine transporter ASCT2 and the uptake of glutamine in both L02 and HepG2 cell lines. The uptake of glutamine and the GSH level was increased in both L02 and HepG2 cell lines after ASCT2 overexpression. The ROS level was inhibited by ASCT2 overexpression upon topotecan treatment in both L02 and HepG2 cell lines. Topotecan-induced hepatocellular apoptosis and proliferation inhibition were attenuated by ASCT2 overexpression in both L02 and HepG2 cell lines.ConclusionTopotecan-induced hepatocytes death is dependent on ASCT2 down-regulation, which causes oxidative stress via inhibiting GSH production.     

以拓扑替康为基础的联合诱导方案治疗难治及复发急性粒细胞白血病16例报告

目的：评价以拓扑替康为基础的联合诱导方案治疗难治及复发急性粒细胞白血病(AML)的疗效及不良反应。方法：采用以拓扑替康为基础的联合诱导方案治疗难治及复发AML患者16例。所有患者接受1个疗程拓扑替康组成的联合化疗方案(拓扑替康、环磷酰胺、阿糖胞苷)后，定期检查血细胞计数、骨髓中白血病细胞比例，定期复查肝、肾功能等。结果：7例患者在接受1个疗程诱导缓解化疗后达到完全缓解，2例达部分缓解，总缓解率为56．3％；7例患者无反应。主要不良反应为骨髓抑制。结论：以拓扑替康为基础的诱导缓解方案对部分难治及复发AML患者具有确切疗效。     

The effect of quercetin on topotecan cytotoxicity in MCF-7 and MDA-MB 231 human breast cancer cells

BACKGROUND: Topotecan, which is a Camptothecin derivative, shows a large spectrum in anti-tumor activity. Topotecan exerts its cytotoxic effect on tumor cells mainly by inhibition of topoisomerase I activity resulting in double-strand DNA breaks. In our study, we investigated the combined cytotoxic action of Topotecan and Quercetin in MCF-7 and MDA-MB 231 human breast cancer cells. To examine the possible relation between the cytotoxic activity of Topotecan and oxidative stress, we measured ROS and nitrite levels in both human breast cell lines. MATERIALS AND METHODS: MCF-7 and MDA-MB 231 cells were exposed to Topotecan, Quercetin, or a combination of both agents for 24 h at 37 degrees C. The viability of the cells was measured using the colorimetric MTT (3-(4,5)-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. We determined reactive oxygen species and nitrite levels as indicators of oxidative stress in both cell lines with and without Topotecan and/or Quercetin incubations using fluorometric dichlorofluorescin diacetate (DCFH-DA) and diaminonaphtalene (DAN) assay. RESULTS: The IC(50) concentration of Topotecan was 100 ng/ml in MCF-7 cell line and 160 ng/ml in MDA-MB231 cell line. Treatment with Quercetin enhanced cytotoxicity of Topotecan as 1.4-fold in MCF-7 and 1.3-fold in MDA-MB-231 cell line. A significant increment on ROS and nitrite levels was found in MCF-7 and MDA-MB-231 cells following Topotecan incubation. CONCLUSIONS: Our results suggest that Topotecan has cytotoxic activity against both of the breast cancer cell lines in vitro. A combination with Quercetin increases efficacy of Topotecan in the treatment of breast cancers. Our results indicate that increased oxidative stress plays a role in the cytotoxic action of Topotecan.     

拓扑替康联合化疗治疗复发难治性急性髓系白血病的临床探讨

目的:探讨以拓扑替康为主的联合化疗方案对复发难治性急性髓系白血病(AML)的疗效及不良反应.方法:采用以拓扑替康为主的联合化疗方案治疗复发难治性急性髓系白血病12例,8例治疗1疗程,4例治疗2疗程.结果:4例完全缓解,3例部分缓解,总有效率58%.不良反应主要为骨髓抑制.结论:以拓扑替康为主的联合化疗方案对部分复发难治性急性髓系白血病患者具有确切疗效.