用药环境对药物敏化效应的调控作用

用药环境在精神活性物质诱导的行为敏化效应中发挥重要作用。新异环境和匹配环境能明显调节药物诱导的行为敏化,使药物产生敏化的量效曲线左移。环境的调控作用表明成瘾记忆参与了行为敏化的形成过程。该文就用药环境对药物敏化的作用及机制作一综述。

行为敏化模型在精神活性物质研究中的应用

目的探讨精神活性物质滥用与依赖潜力评价的方法。方法查阅相关文献,总结精神活性物质药物敏化的形成机制、相关动物模型的建立、不同种类精神活性物质诱导的药物敏化的特点,以及行为敏化模型在精神活性物质研究中的应用。结果行为敏化模型适用于多种模型动物及不同种类精神活性物质的处理,可应用于机体成瘾形成机制、精神活性物质成瘾模式、药物滥用/依赖障碍治疗方法等的研究。结论行为敏化模型在精神活性物质滥用与潜力评价中有一定价值。

The Expression of NF-Kappa B Family Protein and Its Relationship with Drug Resistance in Breast Cancer Cell Lines

Objective: To study the expression of NFκB family protein in breast cancer cell lines and the relationship between NFκB family protein and the drug resistance.Methods: Expression of P65, IκB-α in 14 breast cancer cell lines and P50 in 11 breast cancer cell lines was detected by Western blot. The sensitivity of the cells to ADM was determined by MTT.Results: 1κB-α located mainly in the cytoplasm. P65 and P50 were in both of cytoplasm and nucleus. The expression level of P50 was higher than that of P65, especially in nucleus. MTT assay showed that IC50 was three-fold higher in the cell lines which expressed P50 in nucleus than those P50 negative in nucleus, but no difference was found in the expression of P65.Conclusion: The expression of P50 in nucleus may predict the chemotherapy resistance in breast cancer, so it can be used as an indicator to predict the prognosis. The expression of P50 is more often in breast cancer, and it may play a more important role in the chemotherapy resistance than other NFκB family members. Key words breast cancer - NFκB - chemotherapy resistance

rAd-p53 enhances the sensitivity of human gastric cancer cells to chemotherapy

AIM： To investigate potential antitumor effects of rAd-p53 by determining if it enhanced sensitivity of gastric cancer cells to chemotherapy. METHODS： Three gastric cancer cell lines with distinct levels of differentiation were treated with various doses of rAd-p53 alone, oxaliplatin （OXA） alone, or a combination of both. Cell growth was assessed with an 3-（4,5）-dimethylthiahiazo （-z-yl）-3,5-diphenytetrazoli- umromide assay and the expression levels of p53, Bax and Bcl-2 were determined by immunohistochemistry. The presence of apoptosis and the expression of caspase-3 were determined using flow cytometry. RESULTS： Treatment with rAd-p53 or OXA alone inhibited gastric cancer cell growth in a time- and dose- dependent manner; moreover, significant synergistic effects were observed when these treatments were combined. Immunohistochemical analysis demonstrated that treatment with rAd-p53 alone, OXA alone or combined treatment led to decreased Bcl-2 expression and increased Bax expression in gastric cancer cells.Furthermore, flow cytometry showed that rAd-p53 alone, OXA alone or combination treatment induced apoptosis of gastric cancer cells, which was accompa- nied by increased expression of caspase-3. CONCLUSION： rAd-p53 enhances the sensitivity of gastric cancer cells to chemotherapy by promoting apoptosis. Thus, our results suggest that p53 gene therapy combined with chemotherapy represents a novel avenue for gastric cancer treatment.

Genistein sensitizes ovarian carcinoma cells to chemotherapy by switching the cell cycle progression in vitro

Objective:To address how genistein sensitizes the chemotherapy-resistant ovarian carcinoma cells and promotes apoptosis in the respect of cell cycle and the regulation of survivin expression in the process.Methods:Ovarian SKOV-3 carcinoma cell line was treated with genistein or cisplatin either alone or in combination.Cell viability was showed by MTT method.Cell cycle and apoptosis were detected by flow cytometry.Survivin mRNA and protein were revealed by RT-PCR and immunocytochemistry,respectively.Results:Genistein could reduce the cell viability in a dose-dependent manner,while cisplatin did so at a much higher level.In contrast,if the two agents were treated in combination,half growth inhibition(IC50) value for cisplatin was reduced remarkably and the effect was synergistic as analyzed by isobologram.In particular,the reduced cell viability was exhibited by a switch in cell cycle progression,as the cells were arrested in G2/M phase and the G0/G1 phase-fraction was significantly decreased.The reduced cell viability appeared to involve apoptosis,based on our results from flow cytometry and Hoechst 33258 staining.In the meanwhile,genistein performed the inhibitory effect on cisplatin-induced survivin expression.Conclusion:Genistein can sensitize ovarian carcinoma cells to cisplatin therapy with the inhibition of survivin expression as the potential mechanism.

Role of integrin β1 in sensitivity to chemotherapy of pulmonary adenocarcinoma A549

Objective:The aim of our study was to investigate the effect of integrin β1 on influencing the sensitivity to chemotherapy of human pulmonary adenocarcinoma A549 cells.Methods:Human pulmonary adenocarcinoma A549 multicellular spheroids(MCS) were constructed with three dimensional cell culture methods.Cell counting using blood cell counter was employed to detect the sensitivity to ADM of A549 MCS before and after blocking integrin β1;integrin β1 expression of A549 MCS and cell apoptosis was detected by flow cytometry.Results:A549 MCS were successfully established.The integrin β1 expression of A549 MCS elevated with the concentration of ADM(< 0.02 μg/mL).Blocking of integrin β1 lead to higher sensitivity to ADM,and IC50 decreased from 0.19 μg/mL to 0.11 μg/mL,and apoptosis rate increased from(15.81 ± 1.87)% to(30.14 ± 2.89)%.Conclusion:The cell adhesion molecules integrin β1 could influence the sensitivity to chemotherapy of A549 MCS and inhibiting of cell apoptosis might be its mechanism.

Application value of ATP based bioluminescence tumor chemosensitivity assay in the chemotherapy for hydrothorax caused by non-small cell lung cancer

Objective： The aim of the study was to investigate the clinical value and application of ATP based bioluminescence tumor chemosensitivity assay （ATP-TCA） in the chemotherapy for hydrothorax caused by non-small cell lung cancer （NSCLC）. Methods： Hydrothorax specimens from 120 NSCLC patients were analyzed by ATP-TCA and the most sensitive chemotherapeutic drugs were used in NSCLC patients （treatment group）. At the same time, 56 NSCLC patients with hydrethorax were admitted in our Hospital （Department of Oncology, The No. 2 People＇s Hospital of Yibin, China） and given chemotherapy without guidance of the ATP-TCA （control group）. Before the third chemotherapeutic cycle, clinical outcomes were analyzed in the two groups. Results： Effective rate of hydrothorax in treatment group was 67%, while 46% in control group （P 〈 0.05）. In refractory hydrothorax patients, they were 69% and 40% （P 〈 0.05）, respectively.In vitro results correlated well with clinical outcomes （P 〈 0.01）. Conclusion： Effective rate of chemotherapy for hydrothorax in NSCLC is higher in treatment group than that in control group. ATP-TCA is especially helpful for refractory hydrothorax.

Empirical Study on Chemotherapeutic Susceptibility of SP Cells in Human Pulmonary Adenocarcinoma Cell Line A549 in Vitro

OBJECTIVE To explore the chemotherapeutic susceptibility of SP cells in human pulmonary adenocarcinoma cell line A549 and the possible mechanism of multidrug resistance.METHODS SP and non-SP （NSP） cells in the cell line A549 were isolated by fluorescence activated cell sorter. The susceptibility of SP and NSP cells to DDP, 5-FU, VP16, NVB and GEM was detected by a drug susceptibility test, and IC50s were calculated 24 h a er the chemotherapy; and then a er a 2-hour IC50 treatment with 5 chemotherapeutic drugs on the 2 subsets of NSP cells, the intracellular drug levels were determined and analyzed using high performance liquid chromatograph.RESULTS There was no statistical signifi cance in comparison of the di. erences in IC50s and in intracellular drug levels a er DDP treatment between the 2 subsets （P 〉 0.05）, （P 〉 0.05）. However,all IC50s of the other 4 drugs were significantly higher in the SP cells than in the NSP cells （P 〈 0.01）. A er the chemotherapy, the intracellular drug levels of the other 4 drugs were significantly lower in SP cells than in NSP cells （P 〈 0.01）.CONCLUSION Compared to NSP cells, SP cells in the cell line A549 have stronger resistance to the chemotherapeutics. The multidrug resistance of SP cells closely correlates with the function of SP cells discharging chemotherapeutic agents.

Study of sensitivity of different chemotherapeutic agents on colon cancer cell line SW480

Objective:The aim of this study was to investigate the sensitivity of chemotherapeutic agents 5-FU,cisplatin(DDP) or TAXOL on colon cancer cell line SW480 with different methods,to find out the best examine time period for further study of chemotherapeutic sensitivities.Methods:The SW480 cell was treated with 5-FU(200μg/mL),DDP(150μg/mL) or TAXOL(50μg/mL) respectively for 4h,8h or 12h.MTT assay was used to examine the cell survival rate,Annexin V/PI assay was used to analysis the apoptosis rate,Western Blot assay was applied to examine the expression of apoptotic protein.Results:(1) Results of MTT assay showed that the survival rate of SW480 cells at 4h,8h or 12h was:5-FU(200μg/mL)96.0%±8.2%,85.4%±7.8%,74.4% ±10.2%(P<0.05);DDP(150μg/mL) 99.0%±6.4%,88.7%±4.7%(P<0.05),46.9%±2.6%(P<0.01);TAXOL(50μg/mL) 51.5%±4.2%(P<0.01),31.9%±3.1%,17.6%±2.3%,or blank group 97.2%±5.8%,98.7%±7.2%,97.5%±7.5% respectively.(2) The apoptosis rate of cancer cells at 4h,8h or 12h was:control group:3.4%±0.2%,6.2%±0.4%,7.0%±0.5%;5-FU(200μg/mL) 4.0%±0.3%,4.8%±0.4%,7.7%±0.7%;DDP(150μg/mL) 8.5%±0.9%,18.6%±1.6%(P<0.05),67.0%±6.2%(P<0.01);or TAXOL(50μg/mL) 32.0%±5.2%(P<0.01),76.6%±8.5%,94.0% ±8.2%,respectively.(3) Western Blot assay showed that the expression of apoptosis associated protein.PARP,X-linked inhibitor of apoptasis(XIAP),Caspase-9 and Bcl-xL were changed.Conclusion:The sensitivity of chemotherapy could be assessed by MTT assay,Annexin V/PI assay and Western Blot.The best examine time of the three chemotherapuc agents was 5-FU(200μg/mL):>12h,DDP(150μg/mL):8-12h,or TAXOL(50μg/mL):<4h.

Mesoporous silica nanorods intrinsically doped with photosensitizers as a multifunctional drug carrier for combination therapy of cancer

Mesoporous silica nanoparticles （MSNs） have attracted tremendous attention in recent years as drug delivery carriers due to their large surface areas, tunable sizes, facile modification and considerable biocompatibility. In this work, we fabricate an interesting type of MSNs which are intrinsically doped with photosensitizing molecules, chlorin e6 （Ce6）. By increasing the amount of Ce6 doped inside the silica matrix, it is found that the morphology of MSNs changes from spheres to rod-like shapes. The obtained Ce6-doped mesoporous silica nanorods （CMSNRs） are not only able to produce singlet oxygen for photodynamic therapy, but can also serve as a drug delivery platform with high drug loading capacity by utilizing their mesoporous structure. Compared to spherical nano- particles, it is found that CMSNRs with a larger aspect ratio show much faster uptake by cancer cells. With doxorubicin （DOX） employed as a model drug, the combined photodynamic and chemotherapy is carried out, achieving synergistic anti-tumor effects both in vitro and in vivo. Our study presents a new design of an MSN-based drug delivery platform, which intrinsically is fluorescent and able to serve as a photodynamic agent, promising for future imaging-guided combination therapy of cancer.