作用于DNA拓扑异构酶的抗癌药研究

近年来,以DNA拓扑异构酶为靶分子设计各类抑制剂,用作抗癌药物的研究异常活跃,代表着肿瘤化疗的又一新方向。本文在介绍DNA拓扑酶功能的基础上,对其抑制剂的作用方式、抗癌机制、以及疗效评价进行了阐述和讨论。

莪芪抗瘤方剂对白血病HL-60细胞的凋亡作用及对细胞内Ca^(2+)水平的影响

目的:研究中药复方莪芪抗瘤方剂在体外对白血病HL-60细胞凋亡作用,并探讨凋亡发生与细胞内Ca2+浓度变化的关系。方法:通过血清药理学方法,选择10%浓度的含药血清与白血病HL-60细胞共同培育24,48,72,96 h后,应用荧光显微镜观察细胞形态,流式细胞仪检测凋亡峰(亚二倍体峰),用Fura-2/AM荧光负载方法测定细胞内Ca2+浓度的变化。结果:10%浓度的含药血清处理组,细胞体积缩小,细胞核固缩,膜起泡,核断裂及形成凋亡小体等,以72 h最为明显;可见DNA含量低于G1期的凋亡细胞群,其凋亡百分率随时间的递增而增加;10%浓度的含药血清处理组的细胞内Ca2+浓度也明显高于对照组(P<0.01)。结论:莪芪抗瘤方剂含药血清诱导白血病HL-60细胞发生凋亡的作用可能与细胞内Ca2+水平上调有关。

参菝抗瘤液联合化疗治疗晚期胃癌的临床观察

目的:评价参菝抗瘤液联合化疗治疗晚期胃癌的临床疗效。方法:将40例晚期胃癌患者随机分为治疗组(参菝抗瘤液+化疗组)和对照组(化疗组)。对照组给予FOLFOX4方案化疗,治疗组同时加用参菝抗瘤液30 m L/d口服,连用1周,2周为一周期。结果:1)治疗组肿瘤近期客观疗效有效率高于对照组,但无统计学意义(P>0.05);2)经治疗后,治疗组患者KPS评分升高率优于对照组,2组比较有统计学意义(P<0.01);3)治疗组体重增加及稳定者比例均高于对照组,2组比较差异有统计学意义(P<0.05);4)骨髓抑制比较,治疗组显著低于对照组(P<0.01);5)消化道反应比较,治疗组明显低于对照组,化疗不良反应小(P<0.05)。结论:参菝抗瘤液联合化疗治疗晚期胃癌有改善生活质量,减轻化疗不良反应的作用。

东北红豆杉叶萃取物抗癌作用的实验研究

为了寻找有效的抗癌药物,对东北红豆杉叶萃取物的抗癌作用进行实验研究。结果表明东北红豆杉正丁醇和乙酸乙酯萃取物对小鼠S_180荷瘤,H_22肝癌、Lewis肺癌等实体癌均有明显抑制作用,其抑制率正丁醇萃取物不及环磷酰胺(P<0.01,0.001),乙酸乙酯萃取物与环磷酰胺抑瘤作用相当(P>0.O5)。且两种萃取物均能明显延长H_22腹水型肝癌小鼠的存活天数,乙酸乙酯作用更为显著。由此提示东北红豆杉萃取物对实体瘤有明显抑制作用。

新上市的抗淋巴瘤药Adcetris可能诱发进行性多灶性脑白质病

2011年8月刚刚在美国获准上市的SeattleGenetics公司抗淋巴瘤静注产品Adcetris（brentuximabvedotin）为一种CD30靶向抗体一药物偶联物，适应证为CD30^＋霍奇金淋巴瘤（HL）和罕见的T细胞非霍奇金淋巴瘤——系统性间变性大细胞淋巴瘤（ALCL）。然而，据美国FDA披露，截至目前，已有3名患者在接受本品治疗数周或数月后出现进行性多灶性脑白质病（PML）体征和症状，如情绪或日常行为异常、精神错乱、思维障碍、失忆、视力下降、说话或行走失常以及半身无力。PML为一类罕见的致死性严重脑部感染。

Using ^(99m)Tc-MIBI to Evaluate the Effects of Chemosensitizer on P-glycoprotein in Multidrug-resistant Carcinoma Cells

To establish a method to evaluate the effects of chemosensitizer onP-glycoprotein using ^(99m)Tc-MIBI, and observe the changes of ^(99m)Tc-MIBI uptake kinetics andP-glycoprotein levels after using verapamil in MDR human breast cells MCF-7/Adr. Methods: MDR breastcarcinoma cells, MCF-7/Adr, were incubated and different protocols were performed. Protocol Ⅰ: achemosensitizer, verapamil (10 μmol/L), was added into cell culture medium, while in control group,the same volume of DMEM was given. Cells were harvested after 2 h incubation with ^(99m)Tc-MIBI.Protocol Ⅱ: Verapamil (10 μmol/L) was added into cell culture medium and incubated for 20 min, 40min, 60 min, 80 min, 8 h, 24 h, 48 h and 72 h respectively. Cells were harvested after 2 hincubation with ^(99m)Tc-MIBI. The radioactivity of the cells was measured and P-glycoproteinexpression levels were determined with immunohistochemical stain. Results: Protocol Ⅰ: After 2hincubation with verapamil the cellular uptake of ^(99m)Tc-MIBI was remarkably higher than controlgroup (t=2.33, P 【 0.05), but there was no difference in P-glycoprotein expression levels betweentwo groups (P 】 0.05). Protocol Ⅱ: In verapamil group, ^(99m)Tc-MIBI uptake was increased withincubation time prolonging (F=58.2, P 【 0.05). When verapamil incubation time surpassed 8 h the^(99m)Tc-MIBI uptake negatively correlated to the P-glycoprotein expression levels (r=-0.73, P 【0.01). However, when incubation time was less than 80 min, there was no correlation between^(99m)Tc-MIBI accumulation and P-glycoprotein levels (r=0.16, P 】 0.05). Conclusion: ^(99m)Tc-MIBImay be used to evaluate the qualitative as well as quantitative change of P-glycoprotein expressionlevels induced by the chemosensitizer, verapamil.

A Bioactive Diterpene from the Chinese Herb Aster souliei

Aster souliei Franch, (Compositae) is a. herbaceous plant distributed innorth China. It has been used in folk medicine as antipyretic, detoxicant, expectorant andantitussive. In an effort to find biologically active components from Chinese medicinal plants ' ,we have examined the aerial parts of this herb, leading to the isolation of a clerodane-typediterpene, 18, 19-dihydroxy-5α, 10β-neo-cleroda-3, 13 (l4)-dien-16, 15-butenolide (1). In thispaper we report the structural elucidation, and the antitumor and antibacterial activities of thiscompound. It was found that 1 possesses moderate cytotoxicity against human leukemia cells (HL-60)and activity against microorganisms.

长春酰胺致过敏反应1例

患者男性，49岁，因进食阻挡感2个月，临床确诊为“食管癌”，于2003年9月18日在外院全麻下行“食管癌切除术”，术后病理报告为“食管溃疡性小细胞未分化癌，累及贲门，区域淋巴0／3未见转移”。2003-09-31转入我院进行化疗，方案及化疗药物由外院提供。既往无药物过敏史。查体：一般情况好，浅表淋巴结无肿大，右侧胸部可见长约30cm手术疤痕，

Conformation and Antitumor Activity of Novel Metal Complexes of Piperazinedithioformates

The in vitro antitumour efficacy of some novel metal complexes of piperazinedi thioformates （SR-M） was examined in six cancer cell lines. The activity was compared with that of piperazinedithioformates. Biological evaluations of a series of SR-M compounds suggest that the compounds 1 c （SR-Cu） and If （SR-Sn） show a potent antitumor activity. The stable conformation structure of SR-Cu as a representative of SR-M was investigated and confirmed by computer workshop.

Partial Beclin 1 silencing aggravates doxorubicin-and Fasinduced apoptosis in HepG2 cells

AIM： To investigate the role of Beclin 1 on the susceptibility of HepG2 cells to undergo apoptosis after anti-Fas antibody or doxorubicin treatment. METHODS： Beclin 1 silencing was achieved using RNA interference. DNA ploidy, the percentage of apoptotic cells and the mitochondrial membrane potential were assessed by flow cytometry. Levels of Beclin 1, BCI-XL and cytochrome c, and the cleavage of poly （ADP-ribose） polymerase （PARP） were assayed by using Western blots. RESULTS： Beclin 1 expression decreased by 75% 72 h after Beclin 1 siRNA transfection. Partial Beclin 1 silencing significantly increased the percentage of subG1 cells 24 and 40 h after treatment with doxorubicin or anti-Fas antibody, respectively, and this potentiation was abrogated by treatment with a pan-caspase inhibitor. Partial Beclin 1 silencing also increased PARP cleavage, mitochondrial membrane depolarization and cytosolic cytochrome c. The pro-apoptotic consequences of partial Beclin 1 silencing were not associated with a decline in Bcl-XL expression.CONCLUSION： Partial Beclin 1 silencing aggravates mitochondrial permeabilization and apoptosis in HepG2 cells treated with an anti-Fas antibody or with doxorubicin.

Treatment of hepatoma with liposome-encapsulated adriamycin administered into hepatic artery of rats

AIM： To observe the therapeutic effects of liposomeencapsulated adriamycin （LADM） on hepatoma in comparison with adriamycin solution （FADM） and adriarnycin plus blank liposome （ADM ＋ BL） administered into the hepatic artery of rats. METHODS： LADM was prepared by pH gradient-driven method. Normal saline, FADM （2 mg/kg）, ADM＋BL （2 mg/kg）, and LADM （2 mg/kg） were injected via the hepatic artery in rats bearing liver W256 carcinosarcoma, which were divided into four groups randomly. The therapeutic effects were evaluated in terms of survival time, tumor enlargement ratio, and tumor necrosis degree. The difference was determined with ANOVA and Dunnett test and log rank test. RESULTS： Compared to FADM or ADM ＋ BL, LADM produced a more significant tumor inhibition （tumor volume ratio： 1.243±0.523 vs 1.883±0.708, 1.847±0.661, P 〈 0.01）, and more extensive tumor necrosis. The increased life span was prolonged significantly in rats receiving LADM compared with FADM or ADM＋BL （231.48 vs 74.66, 94.70） （P 〈 0.05）. CONCLUSION： The anticancer efficacies of adriamycin on hepatoma can be strongly improved by liposomal encapsulation through hepatic arterial administration.

Molecular mechanisms of denbinobin-induced anti-tumorigenesis effect in colon cancer cells

AIM: To explore both the in vitro and in vivo effects of denbinobin against colon cancer cells and clarify its underlying signal pathways. METHODS: We used COLO 205 cancer cell lines and nude mice xenograft model to study the in vitro and in vivo anti-cancer effects of denbinobin. RESULTS: Denbinobin at concentration of 10-20 μmol/L dose-dependently suppressed COLO 205 cell proliferation by MTT test. Flow cytometry analysis and DNA fragmentation assay revealed that 10-20 μmol/L denbinobin treatment induced COLO 205 cells apoptosis. Western blot analysis showed that caspases 3,8,9 and Bid protein were activated by denbinobin treatment to COLO 205 cells accompanied with cytochrome c and apoptosis-inducing factor (AIF) translocation. Pretreatment of MEK 1 inhibitor (U10126), but not p38 inhibitor (SB203580) and JNK inhibitor (SP600125), reversed denbinobin-induced caspase 8, 9 and Bid activation in COLO 205 cells suggesting that extracellular signal-regulated kinase were involved in the denbinobin-induced apoptosis in COLO 205 cells. Significant regression of tumor up to 68% was further demonstrated in vivo by treating nude mice bearing COLO 205 tumor xenografts with denbinobin 50 mg/kg intraperitoneally. CONCLUSION: Our findings suggest that denbinobin could inhibit colon cancer growth both in vitro and in vivo. Activation of extrinsic and intrinsic apoptotic pathways and AIF were involved in the denbinobin-induced COLO 205 cell apoptosis.

Survivin expression in early hepatocellular carcinoma and post-treatment with anti-cancer drug under hypoxic culture condition

AIM： To investigate the expression of survivin during the early stages of hepatocellular cardnoma （HCC）.METHODS： Immunohistochemical expression of survivin in liver tumor and non-tumor tissue specimens taken from 17 patients was compared. In addition, to determine the survivin expression in response to anticancer drugs in early stage HCC, the survivin expression was determined after the treatment of the HCC cells with anti-cancer drugs under hypoxic culture conditions.RESULTS： Survivin proteins were expressed in 64.7% of cells in early HCC specimens. A correlation between the survivin expression rate in the peritumoral hepatocytes and the rate of expression in the HCC specimens （low-rate group vs high-rate group） was observed. The survivin protein concentration in HCC cells was increased by the combination of hypoxia and anti-cancer drugs.CONCLUSION： This study suggests that survivin could be used as a therapeutic target in early HCC.

RECENT PROGRESS IN THE STUDY OF ANTICANCER DRUGS ORIGINATING FROM PLANTS AND TRADITIONAL MEDICINES IN CHINA

Drugs of plant origin have received much attention due to their enormous potential for the prevention and treatment of cancer. Recent progress in the study of anticancer drugs originating from plants and traditional medicines in China is reviewed in this paper, with particular emphasis on taxol, daidzein, acetyl boswellic acid,curcumin and ginsenosid Rh2.

Selenium Distribution Pattern, Antineoplastic and Immunostimulatory Activities of a Novel Organoselenium Compound Eb

Aim To study the distribution pattern, antineoplastic activity and immunocompetence of a novel organoselenium compound Eb and investigate its in vivo antineoplastic potential. Methods Eb was administered to Kunming mice (dosage, 0.1 g·kg^(-1)·d^(-1)) intragastrically for 7 successive days. The contents of selenium in heart, liver, spleen, kidneys, lungs, stomach, brain, muscle, and bone were determined by fluorometric method on the eighth day. MTT assay was used to study tumor growth inhibition of Eb in vitro, and lymphocyte transformation, hemolysin formation and phagocytosis assay were used to study its immunocompetence. Results After 7 days′ administration of Eb, the tissue contents of sele-(nium) in liver, spleen, lungs, kidneys, and bone of mice increased, especially those in liver and spleen increased significan-tly, compared with controls; but no significant changes of such contents were found in muscle, heart, brain, and stomach. Eb demonstrated inhibitory effects on human Bel-7402, BGC-823, and Calu-3 cancer cell lines in vitro. Eb also showed ability to enhance lymphocyte transformation and serum hemolysin formation in vitro and increase the phagocytosis of macrophages. Conclusion The validated antitumor and immunostimulatory activities of Eb suggest a hypothesis that Eb may behave as a biological response modifier when used as an antitumor agent. Eb is worthy of further study in developing a new antineoplastic and immunity enhancing agent in the light of its antitumor activity, immunocompetence and specific distribution in liver, lungs, kidneys, bone, and spleen.

Systemic chemotherapy for hepatocellular carcinoma in non-cirrhotic liver:A retrospective study

AIM:To investigate the efficacy and toxicity of systemic chemotherapy in a retrospective study of patients with hepatocellular carcinoma(HCC)occurring in normal or fibrotic liver without cirrhosis. METHODS:Twenty-four patients with metastatic or locally advanced HCC in a normal or a fibrotic liver were given systemic chemotherapy(epirubicin,cis- platin and 5-fluorouracil or epirubicin,cisplatin and capecitabine regimens).Tumor response,time to pro- gression,survival,and toxicity were evaluated. RESULTS:There were 7 women and 17 men,mean age 54±10 years;18 patients had a normal liver and 6 had a fibrotic liver(F1/F2 on biopsy).Mean tumor size was 14 cm,5 patients had portal vein thrombosis and 7 had metastasis.Patients received a median of 4 chemotherapy sessions.Overall tolerance was good. There were 5 partial responses(objective response rate =22%),and tumor control rate was 52%.Second line surgical resection was possible in two patients.Median survival was 11 mo,and 1-and 2-year overall survival rates were 50%±10%and 32%±11%,respectively. CONCLUSION:In patients with HCC in a non-cirrhotic liver,chemotherapy was well tolerated and associated with an objective response rate of 22%,including two patients who underwent secondary surgical resection.

SENSITIZATION OF ACNU KILLING EFFECTS ON HeLa S3 CELLS BY MGMT ANTI SENSERNA TRANSFECTION

O6 -methylguanine- DNA- methyltransferase (MGMT ) plays a very important role in the cellular resis- tance to nitrosoureas drugs. Inhibition of MGMT might be a useful approach in tumor chemotherapy. In this study, the depletion of MGMT activity by retroviral-mediated antisense RNA transfection were reported. Three retroviral vectors expressing MGMT antisense RNA were constructed and transfected into HeLa S3 cells. The difference of MGMT mRNA, MGMT activity as well as cellular resistance to ACNU before and after transfection were observed. It was found that antisense RNA targeting 5’region and whole length of MGMT mRNA could partially deplete MGMT activity and enhance killing effects of ACNU. However, 3’ region antisense RNA had no effect on MGMT modulation.