Multidrug resistance (MDR) is a key element in the failure of chemotherapies, and development of agents to overcome MDR is crucial to improving cancer treatments. The overexpression of glutathione-S-transferases (GSTs) is one of the major mechanisms of MDR. Because some agents used in traditional Chinese medicine have strong antitumor effects coupled with low toxicity; we investigated the ability of N,N-bis(2-chloroethyl)docos-13-enamide (compound J), the synthesized analog of a highly unsaturated fatty acid from Isatis tinctoria L., to reverse the MDR induced by adriamycin (ADM) in TCA8113/ADM cells. We found that compound J significantly increased the cytotoxicity of ADM in TCA8113/ADM cells, with a reversal fold of 2.461. Analysis of the mechanisms through which compound J reversed MDR indicated that compound J significantly decreased the activity of GSTs and enhanced the depletion of GSH in TCA8113/ADM cells, but did not affect the P-glycoprotein (P-gp) efflux. Taken together, our data suggested that compound J was an excellent candidate for reversing MDR in cancer therapy.

Objective:To study the feasibility and optimal conditions of chemical dye carboxyfluorescein diacetate succinimidyl ester(CFDA-SE) on labeling tumor cells.Methods:TCA was labeled with CFDA-SE on different labelling time,different concentrations and different culture concentrations.Results:At 20min mark,the fluorescence intensity was proportional to the time;the time duration of fluorescence intensity was proportional to the labeling time.But at the mark for more than 20mim,the fluorescence had no significant change in duration.Increasing the marker dye concentration,the fluorescence duration could be extended.Adding dye with 1/4 concentration of the kit to medium,the fluorescence had best lasting effect.Conclusion:CFDA-SE labelling tumor cells has many influence factors,which can not be used in the tumor cell culture experiments needing long time,but can be used for short-term markers of tumor cells with the optimum marking time for 10min and the labeling concentration shown in the kit.concentration of cultured the concentration of the kit 1/4 medium.In coculture,adding dye with 1/4 of kit concentration to medium could obtain the best fluorescent lasting effect.The experiment is simple to be operated and the results are easy to observe.

Objective To investigate the method for the determination of concentration of erucic acid methyl ester in human hepatocellular line BEL-7404.Methods The concentration of erucic acid methyl ester in the blank cell lysate,the medium and the lysate of cells that added erucic acid methyl ester were detected by thin layer chromatography-gas chromatography(TLC-GC),and the relationship between the concentration of erucic acid methyl ester and the peak area.Results A good linear correlation between peak area and concentration were obtained within a concentration range of 50~5 000 μg/ml(r=0.999 95).The amount of erucic acid methyl ester microemulsion got into human hepatocellular line BEL-7404 were 24.9%.Conclusions TLC-GC can determine the concentration of the drug in the cell accurately;this method is simple,rapid and stability.

目的 首次合成未见报道的N,N-二(2-氯乙基)芥酸酰胺,探讨其体内外抗肿瘤活性.方法 ①以芥酸和双(2-氯乙基)胺盐酸盐为原料、吡啶为催化剂合成N,N-二(2-氯乙基)芥酸酰胺,分离纯化后核磁共振谱确证结构;②用N,N-二(2-氯乙基)芥酸酰胺作用于Tca8113,用倒置显微镜镜下观察其对Tca8113细胞的生长状况的影响,PI染色经流式细胞术分析其杀伤效应;③S180小鼠动物肿瘤模型观察N,N-二(2-氯乙基)芥酸酰胺对肿瘤的体内抑制作用.结果 合成出了N,N-二(2-氯乙基)芥酸酰胺并确证了其结构;N,N-二(2-氯乙基)芥酸酰胺于体外0.15～10.0 μg/ml的浓度范围对Tca8113有较强的杀伤效应,杀伤率均超过30%,但与浓度递增无明显的正相关,在100.0 μg/ml以上的浓度反而杀伤效果不佳;体内抑制S180的生长,剂量为5 mg/kg时,抑制作用最好,生命延长率为38.20%,体重平均增长速率为2.45%.结论 采用微型合成法能够快速、方便地合成出N,N-二(2-氯乙基)芥酸酰胺;N,N-二(2-氯乙基)芥酸酰胺在在体内外具有明显的抗肿瘤活性.

A new compound named N,N-dicyclohexyl-N-behenurea had been prepared by the reaction of behenic acid with DCC by means of catalyst of DMAP and the synthetic method was optimizated.Its structure was elucidated by 13C-NMR and 1H-NMR.By observing its on the growth of BEL-7404,researched it on BEL-7404 cells in vitro.The results showed that N,N-dicyclohexyl-N-behenurea can be prepared by the optimizated synthetic method easily and quickly,and the yield was above 85 %.The Killing effect of it on BEL-7404 cells was significant when more than 400 μg/mL.N,N-dicyclohexyl-N-behenurea would be a potential novel anti-tumor lead compound.

Objective To study the synthesis of the N-alcohol erucamide and its activity of anti-tumor in vitro.Methods (1) Through the micro-organic synthesis technology,erucic acid and methanol were coupled with ethanolamine as raw matierals,sodium as catalyst to synthesize the N-alcohol erucamide,isolation and purification achieved by silical gel column chromatography,and Its structure was confirmed by infrared spectra and nuclear magnetic resonance spectrum;(2) BEL-7404 was cultured in media added to the N-ethanol erucamide.The cells's growth was observed in inverted microscope.The effect of inhibiting cancer cells was detected with MTT.Results The N-alcohol erucamide was synthesized successfully;Its strong inhibiting effect was recorded beyond 50.0 μg/ml.The inhibiting rates were all beyond 40%,the inhibitory concentration 50% (IC50) was 101.77588 μg/ml.Conclusion Through the microscale organic synthesis,N-alcohol erucamide can be synthesized quickly and conveniently.N-alcohol erucamide has obvious inhibiting effcet on BEL-7404 cells in vitro.

We hypothesized that the ambient air pollution particles (particulate matter; PM) induce cell cycle arrest in alveolar epithelial cells (AEC). Exposure of PM (25 μg/cm 2 ) to AEC induced cells cycle arrest in G1 phase, inhibited DNA synthesis, blocked cell proliferation and caused decrease in cyclin E, A, D1 and Cyclin E‐ cyclin‐dependent kinase (CDK)‐2 kinase activity after 4 h. PM induced upregulation of CDK inhibitor, p21 protein and p21 activity in AEC. SiRNAp21 blocked PM‐induced downregulation of cyclins and AEC G1 arrest. Accordingly, we provide the evidence that PM induces AEC G1 arrest by altered regulation of G1 cyclins and CDKs.

We studied the effects of fibroblast growth factor (FGF‐10) on H2O2‐induced alveolar epithelial cell (AEC) G1 arrest and the role of G1 cyclins. FGF‐10 prevented H2O2‐induced AEC G1 arrest. FGF‐10 induced 2–4‐fold increase in cyclin E, cyclin A and CDKs (2, 4) alone and in AEC treated with H2O2. H2O2 downregulated cyclin D1; FGF‐10 blocked these effects. FGF‐10 prevented H2O2‐induced upregulation of CDK inhibitor, p21. SiRNAp21 blocked H2O2‐induced downregulation of cyclins, CDKs and AEC G1 arrest. Accordingly, we provide first evidence that FGF‐10 regulates G1 cyclins and CDKs, and prevents H2O2‐induced AEC G1 arrest.

Treatment of solid tumors with combinations of chemotherapeutic agents has not led to significant increases in long-term survival. Recent studies support a role for inhibitors of checkpoint arrest as a means to enhance the cytotoxicity of chemotherapy. We have shown previously that triptolide (PG490), an oxygenated diterpene derived from a Chinese medicinal plant, induces apoptosis in cultured tumor cells and sensitizes tumor cells to topoisomerase inhibitors by blocking p53-mediated induction of p21. Here we extend our studies to a tumor xenograft model and evaluate the efficacy and safety of PG490-88 (14-succinyl triptolide sodium salt), a water-soluble prodrug of PG490. We also look at the combination of PG490 or PG490-88 with CPT-11, a topoisomerase I inhibitor, in cultured cells and in the tumor xenograft model. We show that PG490-88 is a safe and potent antitumor agent when used alone causing tumor regression of lung and colon tumor xenografts. We also show that PG490-88 acts in synergy with CPT-11 to cause tumor regression. A phase I trial of PG490-88 for solid tumors began recently and safety and optimal dosing data should accrue within the next 12 months. Our findings that PG490-88 causes tumor regression and that it acts in synergy with DNA-damaging chemotherapeutic agents suggest a role as an antineoplastic agent and chemosensitizer for the treatment of patients with solid tumors.