Induction of DNA damage in Ehrlich ascites tumour cells by exposure to eupatoriopicrin

The sesquiterpene lactone eupatoriopicrin (EUP) from Eupatorium cannabinum L. has been shown to be cytotoxic in a glutathione (GSH)-dependent way. In order to assess possible DNA damage as a cause for cell death, the study reported was initiated. After 2 hr incubation of Ehrlich ascites tumour cells with EUP, the DNA damage, determined by the use of an alkaline DNA unwinding method, followed by hydroxylapatite column chromatography of degraded DNA, was observed at concentrations only slightly higher than those causing cell death in a clonogenic assay. The amount of EUP, requested to demonstrate DNA damage after a 24-hr post-incubation period lay within the concentration range that was effective in the clonogenic assay (1-10 micrograms/ml). Glutathione (GSH) depletion of the cells to about 99%, by use of buthionine sulphoximine (BSO), enhanced the extent of DNA damage. It is concluded that EUP-induced DNA damage may play a role in the observed cytotoxicity.     

Recombinant interleukin-2 pre-treatment increases anti-tumor response to paclitaxel by affecting lung P-glycoprotein expression on the Lewis lung carcinoma

The aim of the present study was to examine modifications of anti-tumor activity and toxicity of paclitaxel (PLX) when given p.o. after recombinant interleukin-2 (rIL-2) to Lewis lung carcinoma-bearing mice. PLX was given orally to mice at the dose of 15 mg/kg on day 8 and 30 mg/kg on day 15, either alone or after 16.5 microg of rIL-2 given i.p. twice a day either 1 or 3 days before. The anti-tumor activity was higher and PLX hematological toxicity not increased if orally administered PLX was given after a 3-day rIL-2 pre-treatment rather than if given alone. Lung metastasis was significantly lower and s.c. tumors were smaller in the PLX+rIL-2 group than in the PLX or rIL-2 or non-treated groups. In addition, a decrease in lung P-glycoprotein expression (investigated by Western blot analysis) was observed 1 h after the last administration of rIL-2 on day 7.     

Antitumor activity of calcium in combination with antitumor agents against Lewis lung carcinoma

The antitumor activity of calcium gluconate in combination with mitomycin C and 5-fluorouracil was examined against subcutaneously implanted Lewis lung carcinoma-bearing C57BL/6 mice. The mice were divided into four groups: group 1 received mitomycin C (2 mg/kg) and 5-fluorouracil (50 mg/kg) intraperitoneally once a week for four weeks beginning from the day after implantation of tumors, as well as calcium gluconate (155 mg/kg) twice a week for the same four weeks; group 2 received only mitomycin C and 5-fluorouracil; group 3 received only calcium gluconate; group 4 received a vehicle (physiological saline). Significantly enhanced inhibition of tumor growth was observed neither in a comparison between groups 3 and 4, nor in a comparison between groups 1 and 2 (expect on day 20 post implantation). Thus calcium gluconate given alone or in combination with antitumor agents hardly appeared to possess effective antitumor activity.     

Anti-tumorigenic activity of sophoflavescenol against Lewis lung carcinoma in vitro and in vivo

This study examined the in vitro cytotoxic activity and in vivo antitumor activity as well as intracellular apoptotic capacities of a prenylated flavonol, sophoflavescenol from Sophora flavescens, to evaluate prospective anti-tumorigenic drugs, and antitumor potential. In addition, the in vitro antioxidant and anti-inflammatory capacities were evaluated. Despite the small effect on human breast adenocarcinoma (MCF-7), sophoflavescenol showed cytotoxicity against human leukaemia (HL-60), Lewis lung carcinoma (LLC), and human lung adenocarcinoma epithelial (A549) cells. Interestingly, it also exerted potent in vivo antitumor activity by tumor growth inhibition in the LLC tumor model as well as apoptotic activity by caspase-3 activation in HL-60 cells. In addition, it exhibited potent antioxidant activities in 1,1-diphenyl-2-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radicals and lipid peroxidation assays. Sophoflavescenol exerted notable anti-inflammatory activity by inhibiting nitric oxide generation and tert-butylhydroperoxide-induced ROS generation rather than inhibiting nuclear factor kappa B activation in RAW 264.7 cells. The findings show that the antioxidant, anti-inflammatory, and apoptotic activities of sophoflavescenol might contribute to the antitumor activity without severe side effects, highlighting its potential for chemoprevention and/or anticancer drugs due to multi-effective targets in almost all stages of tumorigenesis, including initiation, promotion, and progression.     

DCLAK11对非小细胞肺癌细胞HCC827的抗肿瘤作用

目的：研究DCLAK11对非小细胞肺癌（non-small cell lung cancer,NSCLC）的抗肿瘤作用及其机制。方法：SRB法和克隆形成实验检测DCLAK11对HCC827细胞增殖的影响;流式细胞术检测DCLAK11对HCC827细胞凋亡的影响;细胞划痕愈合实验检测DCLAK11对人脐静脉血内皮细胞HUVEC迁移的作用;免疫荧光实验检测DCLAK11对HCC827细胞表皮生长因子受体（epidermal growth factor receptor,EGFR）磷酸化的作用;ATP竞争实验考察DCLAK11对EGFR激酶活性是否具有ATP竞争性特性。结果：DCLAK11显著抑制NSCLC细胞HCC827的细胞活性（P<0.01）及克隆形成;DCLAK11可诱导HCC827细胞发生凋亡;DCLAK11浓度及时间依赖性地抑制血管内皮细胞HUVEC的划痕愈合（P<0.01）;DCLAK11抑制HCC827细胞EGFR的磷酸化;DCLAK11对EGFR激酶活性的抑制作用具有ATP竞争性。结论：DCLAK11是ATP竞争性的小分子激酶抑制剂,可显著抑制NSCLC细胞HCC827的增殖及诱导该细胞发生凋亡,以上作用可能与DCLAK11抑制EGFR激活相关。此外,DCLAK11还具有抑制血管新生的作用。     

灯盏花素对博来霉素诱导小鼠肺纤维化的保护作用

目的观察灯盏花素对肺纤维化的保护作用,探讨其可能的作用机制。方法观察灯盏花素对体外培养小鼠胚肺成纤维细胞L929增殖、激活及细胞外基质分泌的影响;应用博来霉素诱导小鼠肺纤维化模型,观察灯盏花素对肺纤维化的保护作用。结果灯盏花素体外对小鼠胚肺成纤维细胞L929无直接细胞毒作用,但能抑制TGF-β1促进的增殖、激活及层粘连蛋白(LN)、Ⅰ型胶原(ColⅠ)分泌。体内灯盏花素能抑制博来霉素诱导的小鼠血清TGF-β1升高,阻止博来霉素诱导的小鼠肺脏SOD、POD、CAT降低,并降低肺脏羟脯氨酸、胶原、MDA及TGF-β1含量。结论灯盏花素有肺纤维化保护作用,其机制可能是通过增加抗氧化防御系统和阻止TGF-β信号实现的。     

Antitumor activity of ascorbic acid in combination with antitumor agents against Lewis lung carcinoma

Antitumor activity of ascorbic acid in combination with antitumor agents (mitomycin C and 5-fluorouracil) was examined against subcutaneously implanted Lewis lung carcinoma-bearing C57BL/6 mice by feeding them an ascorbic acid-deficient diet. The mice were divided into four groups: group 1 received intraperitoneally mitomycin C (2 mg/kg) and 5-fluorouracil (50 mg/kg) once a week for four weeks beginning from the day after implantation of tumors, as well as ascorbic acid (1000 mg/kg) twice a week for the same four weeks; group 2 received only mitomycin C and 5-fluorouracil; group 3 received only ascorbic acid; group 4 received a vehicle (physiological saline). Tumor growth of group 1 compared with the other three groups, and that of group 2 compared with groups 3 and 4, was significantly inhibited by day 13 post implantation. Histological examinations of tumor tissues at 10 days after implantation of tumors already showed degenerative changes which indicated these antitumor effects.     

Effects of naturally occurring stilbene glucosides from medicinal plants and wine, on tumour growth and lung metastasis in Lewis lung carcinoma-bearing mice

Stilbene glucosides are naturally occurring phytoalexins, found in a variety of medicinal plants. Among the stilbene derivatives, resveratrol 3-O-D-glucoside (piceid) is found in grapes and wine. We studied the effects of stilbene glucosides isolated from medicinal plants and grapes on tumour growth and lung metastasis in mice bearing highly metastatic Lewis lung carcinoma (LLC) tumours. We also studied the inhibitory effects of stilbene glucosides on differentiation of human umbilical vein endothelial cells (HUVECs) to form a capillary network. Tumour growth in the right hind paw and lung metastasis were inhibited by oral administration of the stilbene glucosides, piceid and 2,3,5,4'-tetrahydroxystilbene-2-O-D-glucoside for 33 consecutive days, in LLC-bearing mice. As the number of CD8+ and NK1.1+ T cells in the spleen was not affected, the inhibitory effects of these stilbene glucosides on tumour growth and lung metastasis could not be explained by natural killer or cytotoxic T lymphocyte activation. Piceid inhibited the DNA synthesis in LLC cells at a concentration of 1000 microM, but not at lower concentrations (10-100 microM). 2,3,5,4'-Tetra-hydroxystilbene-2-O-D-glucoside also inhibited DNA synthesis in LLC cells (IC50 81 microM). In addition, both stilbene glucosides inhibited the formation of capillary-like tube networks (angiogenesis) of HUVECs at concentrations of 100 to 1000 microM. We suggest that the antitumour and antimetastatic activity of the stilbene glucosides, piceid and 2,3,5,4'-tetrahydroxystilbene-2-O-D-glucoside, might be due to the inhibition of DNA synthesis in LLC cells and angiogenesis of HUVECs.     

7-乙基-10-羟基喜树碱脂质体的抗肿瘤作用

目的探索7-乙基-10-羟基喜树碱(7-ethyl-10-hydroxy camptothecin,SN-38)脂质体的体内外抗肿瘤作用。方法体外实验采用噻唑蓝[3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide,M TT]法检测SN-38脂质体对9种人源肿瘤细胞的抑制作用;体内实验利用A549非小细胞肺癌和SKOV-3卵巢癌荷瘤裸鼠模型,以伊立替康为阳性对照药,统计裸鼠体质量、瘤体积、抑瘤率、相对肿瘤增殖率等指标,考察不同剂量的SN-38脂质体对肿瘤的生长抑制作用。结果体外实验表明SN-38脂质体能抑制多种肿瘤细胞增殖;体内实验表明SN-38脂质体高、中、低剂量(4、2、1 mg·kg-1)对A549荷瘤裸鼠的抑瘤率分别为69.75%、52.08%和29.78%,SN-38脂质体高、中、低剂量(8、4、2 mg·kg-1)对SKOV-3荷瘤裸鼠的抑瘤率分别为54.19%、38.91%、23.71%。结论 SN-38脂质体体外对多种肿瘤细胞有较好的抗增殖作用,体内对A549非小细胞肺癌及SKOV-3卵巢癌荷瘤裸鼠有较好的治疗作用。     

The effects of delayed treatment with sialyl Lewis X against lipopolysaccharide-induced acute lung injury in rabbits

The therapeutic effects of a selectin inhibitor against lipopolysaccharide-induced acute lung injury were studied in rabbits by using sialyl Lewis X-oligosaccharide. Lipopolysaccharide-induced acute lung injury, as characterized by an impairment of pulmonary gas exchange, clinically resembles that of the acute respiratory distress syndrome. Delayed treatments with sialyl Lewis X-oligosaccharide (55 mg kg(-1) i.v. bolus injection 0.5, 1 or 2 h after lipopolysaccharide administration+36 mg kg(-1) h(-1) i.v. infusion for 5.5, 5 or 4 h, respectively) prevented the lipopolysaccharide-induced impairments in pulmonary gas exchange, as well as the accumulation of polymorphonuclear leukocytes in the lung tissue. In contrast, this agent had no significant effects on lipopolysaccharide-induced systemic hypotension, the decrease in the number of circulating white blood cells and platelets or the decline in blood pH.This is the first demonstration that sialyl Lewis X-oligosaccharide is effective against the impairments in pulmonary gas exchange even if administered 0.5, 1 or 2 h following the lipopolysaccharide injection.     

Combined chemo/anti-angiogenic cancer therapy against Lewis lung carcinoma (3LL) pulmonary metastases

A6 is an eight amino acid peptide derived from the non-receptor binding region of urokinase plasminogen activator (uPA), which interferes with the uPA/uPA receptor system. A6 has been synthesized as a potential anti-angiogenic, anti-cancer agent. The current study has investigated the potential therapeutic activity of A6 in the Lewis lung carcinoma (3LL) model of pulmonary metastasis. A6 was found to have direct anti-tumor activity against established 3LL pulmonary metastases at a low tumor burden (10-20 colonies per lung) and was therapeutic in combination with cyclophosphamide at high tumor burdens (> 100 colonies per lung). Mechanistic studies have revealed that A6 directly inhibits the invasion of 3LL cells through a Matrigel model basement membrane by 40-45%. Moreover, treatment with either A6 or doxorubicin resulted in thicker tubes in endothelial tube formation studies. Our results suggest that A6, by virtue of its anti-invasive and anti-angiogenic properties, might work additively or synergistically with chemotherapeutic agents and thereby contribute to enhanced therapy of established 3LL cancer metastases.     

Protective effects of sialyl Lewis X and anti-P-selectin antibody against lipopolysaccharide-induced acute lung injury in rabbits.

The prophylactic effects of selectin inhibitors on lipopolysaccharide-induced acute lung injury were studied in rabbits by using sialyl Lewis X-oligosaccharide and PB1.3, an anti-human P-selectin monoclonal antibody. Lipopolysaccharide-induced acute lung injury resembles that of the acute respiratory distress syndrome, in which there is a decrease in arterial blood oxygen tension (PaO2) and an increase in the difference between alveolar and arterial oxygen tension (A-aDO2). Prophylactic treatment with the selectin inhibitors, sialyl Lewis X-oligosaccharide (55 mg kg(-1) i.v. bolus injection immediately before lipopolysaccharide administration + 36 mg kg(-1) h(-1) i.v. infusion for 4 h) and PB1.3 (5 mg kg(-1) i.v. bolus injection immediately before lipopolysaccharide administration), prevented the lipopolysaccharide-induced impairments in pulmonary gas exchange. In contrast, these agents had no significant effects on lipopolysaccharide-induced systemic hypotension, the decrease in the number of circulating white blood cells and platelets, the decline in blood pH, or the increase in arterial CO2 tension (PaCO2). These results indicate that selectin inhibitors including sialyl Lewis X-oligosaccharide and the anti-P-selectin antibody, PB1.3, attenuate lipopolysaccharide-induced acute lung injury in rabbits. This is the first demonstration that P-selectin is directly involved in the development of lipopolysaccharide-induced impairments in pulmonary gas exchange.     

In vitro and in vivo assessment of activity of new anilino-substituted analogues of amsacrine against Lewis lung carcinoma

A number of new anilino ring variants of the anti-tumour drug amsacrine have been synthesised and their anti-tumour activity evaluated. In vitro selectivity, as measured by the logarithmic ratio of IC50 growth inhibition assays against P388 leukaemia and Lewis lung carcinoma cells, was significantly correlated with the increase in life span in vivo with the P388 leukaemia and Lewis lung lines, whereas the growth inhibition IC50 values alone correlated with the dose potency in mice. It was thus possible to predict both in vivo anti-tumour activity and dose potency, identifying compounds with high therapeutic activity, using a combination of two in vitro assays. Two new compounds have been identified which provide, along with an acridine-substituted analogue of amsacrine which is at present in clinical trial (CI-921), a high proportion of cures against the Lewis lung tumour in vivo. Since amsacrine is thought to interact with the enzyme topoisomerase II, and because the anilino group of 9-anilinoacridine derivatives is thought to project from the DNA intercalation site of the drug-DNA complex, these compounds may be of particular interest in mode of action studies.     

The anti-tumor effect and mechanisms of action of penta-acetyl geniposide

Gardenia, the fruit of Gardenia jasminoides Ellis, has been widely used to treat liver and gall bladder disorders in Chinese medicine. It has been shown recently that geniposide, the main ingredient of Gardenia Fructus, exhibits the anti-tumor effect. In this review, we discuss the anti-tumor effect and possible mechanisms of a derivative from Gardenia Fructus, penta-acetyl geniposide ((Ac)5GP). It has been demonstrated that (Ac)5GP plays more potent roles than geniposide in chemoprevention. (Ac)5GP decreased DNA damage and hepatocarcinogenesis induced by aflatoxin B1 (AFB1) by activating the phase II enzymes glutathione S-transferase (GST) and GSH peroxidase (GSH-Px). It reduced the growth and development of inoculated C6 glioma cells especially in pre-treated rats. In addition to the preventive effect, (Ac)5GP exerts its actions on apoptosis and growth arrest. Treatment of (Ac)5GP caused DNA fragmentation of glioma cells. (Ac)5GP induced sub- G1 peak through the activation of apoptotic cascades PKCdelta/JNK/Fas/caspase8 and caspase 3. Besides, p53/Bax signaling was suggested to be involved in (Ac)5GP-induced apoptosis, though its downstream cascades needs further clarified. (Ac)5GP has also been shown to inhibit DNA synthesis of tumor cells. It arrested cell cycle at G0/ G1 by inducing the expression of p21, thus suppressing the cyclin D1/cdk4 complex formation and the phosphorylation of E2F. The phosphorylation status of p53 on serine 392 correlated with the process of growth arrest. Evidences from the in vivo experiments showed that (Ac)5GP is not harmful to liver, heart and kidney. In conclusion, (Ac)5GP is highly suggested to be an anti-tumor agent for development in the future.     

中药重楼活性成分抗肿瘤的作用机制

重楼是中医临床常用的中药,具有清热解毒,消肿止痛,凉肝定惊之功效,近年来随着中药提取技术的发展,对重楼的活性成分的药理研究逐渐增多,其抗肿瘤作用及其机理日益受到研究人员的重视。关于重楼中活性成分的抗肿瘤的机制的研究是未来研究的一个方向。     

胡桃楸提取物的抗肿瘤作用

目的探讨胡桃楸提取物SH体内外抗肿瘤活性。方法体外实验应用MTT法检测SH对人宫颈癌细胞株HeLa、小鼠腹水型肝癌细胞株Hca-F的增殖抑制作用;体内实验应用小鼠S180实体瘤动物模型,通过对荷瘤小鼠体质量以及抑瘤率的影响,评价SH不同剂量(4.5、9.0、18.0 mg·kg-1)以及与化疗药物环磷酰胺(cyclophosphamide,CTX)联合用药对S180肉瘤的生长抑制作用。结果体外实验表明,SH可以显著抑制HeLa、Hca-F肿瘤细胞的增殖;体内实验表明,SH具有明显的抑瘤作用,中、高剂量组(9、18 mg·kg-1)的抑瘤率分别为25.9%和35.3%,与CTX联合用药时,能够提高CTX的抑瘤率,中、高剂量组(9+10 mg·kg-1、18+10 mg·kg-1)抑瘤作用呈现相加作用。结论胡桃楸提取物SH,在体外能够明显抑制HeLa、Hca-F肿瘤细胞的增殖,在体内能够抑制荷瘤小鼠S180肉瘤生长,提示胡桃楸提取物SH具有一定的抗肿瘤活性。     

Studies on the mechanism of action of the tumour inhibitory triazenes

A series of imidazole and phenyl dialkyi triazenes were synthesized and investigated for their anti-cancer activity in experimental animals. Active triazenes had a broad spectrum of anti-tumour action and like bischloroethylnitrosourea (BCNU) were active against tumours not sensitive to conventional alkylating agents. It was confirmed that at least one N-methyl group was necessary for anti-cancer activity but there was no correlation between dealkylation by liver microsomes and activity since a diethyl triazene was readily dealkylated but not active. A factor appears to be present in normal cell cytoplasm which can detoxify triazenes but which is absent from tumours sensitive to these agents.     

吉非替尼时辰给药Lewis肺癌荷瘤小鼠的药效学研究

目的 探讨吉非替尼按时辰给药荷瘤小鼠的药效学特点。方法 利用C57BL/6小鼠建立Lewis肺癌小鼠模型,将荷瘤小鼠随机分成7组,每组8只,分别为对照组,8：00、12：00、16：00、20：00、24：00和次日4：00时给药的实验组（A、B、C、D、E、F组）。ig给药50 mg/kg,对照组给予相同剂量含有羧甲基纤维素钠的蒸馏水。每天观察小鼠的生存质量和肛周红肿的数量;每3天测定小鼠肿瘤的直径,计算小鼠的肿瘤体积。经过3周的给药,小鼠进行眼眶取血,处死小鼠并剥离肿瘤,称定质量,计算抑瘤率。取部分肿瘤组织做病理切片,观察肿瘤组织坏死情况;同时取小鼠皮肤组织进行扫描电镜观察。运用ELISA技术检测血液中IL-6的水平。结果 吉非替尼可以明显地抑制荷瘤小鼠肿瘤的生长。与其他实验组比较,A组（8：00时给药）小鼠肿瘤体积增长最缓慢,其抑瘤率最高,F组（次日4：00给药）次之。病理学分析显示A组（8：00时给药）的肿瘤组织坏死情况最严重。通过扫描电镜观察上皮细胞发现,A组（8：00时给药）和F组（次日4：00时给药）的上皮细胞损伤较轻,其肛周红肿发生率和IL-6水平较其他实验组低。结论 吉非替尼对荷瘤小鼠的抗肿瘤作用和毒副作用存在一定的时辰节律性,8：00和4：00时疗效较好。     

唾液酸修饰盐酸多柔比星脂质体的药效学考察

目的考察唾液酸(sialic acid,SA)修饰盐酸多柔比星(doxorubicin hydrochloride,DOX)脂质体的肿瘤治疗效果。方法分别制备普通DOX脂质体、聚乙二醇化的DOX脂质体和SA修饰DOX脂质体,并以质量分数5%葡萄糖注射液和DOX溶液为对照,考察了3种脂质体对S180荷瘤小鼠的肿瘤治疗作用。结果 SA修饰DOX脂质体的肿瘤抑制率最高,为97.77%,与其他制剂比较具有极显著差异(P<0.01)。结论 SA修饰脂质体能够使DOX更大程度地发挥抗肿瘤作用,具有较好的临床应用前景。