端粒酶活性与卵巢癌细胞系药物敏感性的关系

目的探讨端粒酶活性与上皮性卵巢癌细胞系药物敏感性的关系.方法使用顺铂作用于敏感细胞株A2780及耐药细胞株AD60.在四甲基偶氮唑盐(MTT)法测定耐药倍数的基础上,应用聚合酶链反应-聚丙烯酰胺凝胶电泳(PCR-PAGE)方法测定端粒酶活性.结果经MTT测定卵巢癌耐药细胞株AD60的耐药倍数为2.4.A2780端粒酶活性随药物浓度的递增明显降低,而AD60降低不明显.结论端粒酶活性与上皮性卵巢癌细胞对细胞毒性药物的敏感性相关.     

增殖细胞核抗原与卵巢癌细胞系化学敏感性的关系

目的探讨增殖细胞核抗原(PCNA)与上皮性卵巢癌细胞系化学敏感性的关系.方法使用顺为铂作用于A2780及AD60细胞株.在MTT法测定耐药倍数基础上,用ABC检测PCNA表达.结果MTT测定MD60的耐药倍数为2.4.A2780 PCNA的表达低于AD60,且随药物浓度的递增染色较耐药组明显变浅.A2780、AD60相同药物浓度作用后PCNA的表达有显著性差异(P＜0.01);同一细胞株不同药物浓度作用后PCNA表达有显著性差异(P＜0.01).结论增殖细胞核抗原表达与上皮性卵巢癌细胞对细胞毒性药物的化学敏感性呈负相关.     

Interaction between novel anticancer agents and radiation in non-small cell lung cancer cell lines.

Integration of chemotherapy and radiation is the standard practice in the management of locally advanced inoperable NSCLC. To assess the biological interaction between third generation chemotherapeutic agents and radiation in non-small cell lung cancer (NSCLC) in vitro, we tested a number of different drugs (paclitaxel, docetaxel, gemcitabine, topotecan, SN-38 and cisplatin) combined with radiation, in lung cancer cell lines. Cellular chemosensitivity was determined, using the semi-automated colorimetric MTT assay, after 48, 72 and 96 h of exposure to increasing drug concentrations, (0.001-100 microM) and radiation doses (100-400 cGy). Cell lines used were the adenocarcinoma (ADK), A-549, and the squamous-cell carcinoma (SCC), LX-1. Cells were pre-treated with anticancer agents at 24, 12 and 0 h before irradiation. Cytofluorimetric cell cycle analysis was performed. A significant S-phase block or a G(2)/M block was seen with gemcitabine and topotecan or paclitaxel pre-treatment, respectively. Apoptosis was seen only after paclitaxel exposure in the A-549 cell line. Despite a similar pattern of cell-kinetic changes induced by chemotherapy pre-treatment in all cell lines, the adenocarcinoma A-549 cell line was not radiosensitized by any of the anticancer agents tested, whereas synergism was observed in the LX-1 squamous carcinoma cell line, when exposed to gemcitabine, SN-38, topotecan and cisplatin. Paclitaxel, despite a favourable cell cycle effect, was not found to be synergistic with radiotherapy in our experimental model. In conclusion, the observed synergism appears to be dose- and timing-independent and seems to be related to the histological subtype being present in SCC only. Favourable perturbation of the cell cycle is evident with all the new agents tested in both cell types, but was not sufficient to produce synergism with radiation.     

The p53 tumor suppressor gene in anticancer agent-induced apoptosis and chemosensitivity of human gastrointestinal cancer cell lines

Purpose: While the target of many anticancer agents has been identified, the processes leading to killing of the cancer cells and the molecular basis of resistance to the drugs are not well understood. We used human gastrointestinal cancer cell lines and examined how anticancer agents induced cell killing and how the chemosensitivity of these lines was determined. Methods: Twelve gastrointestinal cancer cell lines were examined for the presence of either a wild-type or mutant p53 gene by direct sequencing. We also determined whether or not cell killing would occur when the cell lines were exposed to anticancer drugs. The sensitivity to the anticancer agents was determined based on colony formation. Results: All 12 gastrointestinal cancer cell lines carried either a wild-type or mutant p53 gene. Three lines, MKN45, MKN74 and COLO320, carried the wild-type p53 gene, and nine carried the mutant p53 gene. When three lines were exposed to the anticancer agents etoposide, doxorubicin (DXR) or 5-fluorouracil (5-FU), cell death ensued. In these cells, the population of cells in G₁ phase increased after exposure to high-dose anticancer agents, but cells in G₂ phase increased when exposed to low-dose anticancer agents. Our observations support the concept that cells carrying the wild-type p53 gene tend to be sensitive to etoposide and DXR and, in particular, deletion of the p53 function results in a greater resistance to anticancer agents. Conclusion: Based on our findings, human gastrointestinal cancer-related cell death apparently occurs via a p53-dependent pathway. A relationship was observed between the induction of cell death and chemosensitivity. Received: 22 December 1997 / Accepted: 1 April 1998     

Histone deacetylase inhibitor, trichostatin A, increases the chemosensitivity of anticancer drugs in gastric cancer cell lines

Epigenetic alterations of the histone acetylation play an important role in the regulation of gene expression associated with cell cycles and apoptosis that may affect the chemosensitivity of gastric carcinomas. Recently, a histone deacetylase inhibitor, trichostatin A (TSA), was proven to be a chemo-sensitizer on human erythroleukemia cells. With the aim of improving the chemotherapeutic efficacy of gastric carcinoma, the effect of TSA on the chemosensitivity of several anticancer drugs in gastric carcinoma cells was investigated. Human gastric cancer cell lines, OCUM-8 and MKN-74, and 5 anticancer drugs, 5-fluorouracil (5-FU), paclitaxel (PTX), oxaliplatin (OXA), irinotecan (SN38) and gemcitabine (GEM) were used. In both gastric cancer cell lines, a synergistic anti-proliferative effect by the combination of TSA (30 ng/ml) with 5-FU, PTX or SN38 showed a synergistic anti-proliferative effect in OCUM-8 and MKN-74 cells. TSA increases the expression of p21, p53, DAPK-1 and the DAPK-2 gene in both OCUM-8 and MKN-74 cells. In conclusion, TSA is a promising chemotherapeutical agent in combination with anticancer drugs of 5-FU, PTX and SN38 in gastric cancer cell lines. The up-regulation of p53, p21, DAPK-1 and DAPK-2 might be associated with the synergistic effect of TSA.     

Potentiation of some anticancer agents by dipyridamole against drug-sensitive and drug-resistant cancer cell lines

In this study, we have used two different vincristine (VCR)-resistant variants, VJ-300 and HC-7-5/VCR. VJ-300 was isolated from a human cancer KB cell line and HC-7-5/VCR from a human cancer HC-7-5 cell line. VJ-300 and HC-7-5/VCR are both multidrug-resistant (MDR) variants, showing resistance to multiple anticancer drugs such as VCR, adriamycin, actinomycin D and daunomycin. Dipyridamole, a specific inhibitor of nucleoside transport, potentiated these anticancer drugs about 2- to 10-fold against KB and VJ-300. Dipyridamole almost completely reversed drug resistance to actinomycin D in VJ-300 cells with about a 70-fold higher resistance to actinomycin D. Dipyridamole inhibited the efflux of actinomycin D and VCR from VJ-300 cells. Dipyridamole enhanced the uptake of VCR but not that of actinomycin D in VJ-300 and KB. Dipyridamole at 10-100 microM inhibited photoaffinity labeling with [3H]azidopine of the cell-surface protein P-glycoprotein in VJ-300 cells. Dipyridamole potentiated 5-fluorouracil and hexylcarbamoyl-5-fluorouracil in cultured KB and VJ-300, but it annihilated the cytotoxic action of 5-fluorouridine. Potentiation of 5-fluorouracil by dipyridamole against HC-7-5 and HC-7-5/VCR was also observed, but appeared to be less than in VJ-300 and KB cells. Dipyridamole almost completely inhibited the cellular accumulation of 5-fluorouridine, but not that of 5-fluorouracil. Thus, dipyridamole appeared to potentiate anticancer agents through pleiotropic action sites, one of which is inhibition of enhanced efflux of MDR cell lines and the other of which is inhibition of nucleoside transport. Dipyridamole might be a useful and potent agent to potentiate anticancer agents and reverse drug-resistance.     

An integrated database of chemosensitivity to 55 anticancer drugs and gene expression profiles of 39 human cancer cell lines

To explore genes that determine the sensitivity of cancer cells to anticancer drugs, we investigated using cDNA microarrays the expression of 9216 genes in 39 human cancer cell lines pharmacologically characterized on treatment with various anticancer drugs. A bioinformatical approach was then exploited to identify genes related to anticancer drug sensitivity. An integrated database of gene expression and drug sensitivity profiles was constructed and used to identify genes with expression patterns that showed significant correlation to patterns of drug responsiveness. As a result, sets of genes were extracted for each of the 55 anticancer drugs examined. Whereas some genes commonly correlated with various classes of anticancer drugs, other genes correlated only with specific drugs with similar mechanisms of action. This latter group of genes may reflect the efficacy of each class of drugs. Therefore, the integrated database approach of gene expression and chemosensitivity profiles may be useful in the development of systems to predict drug efficacies of cancer cells by examining the expression levels of particular genes.     

非小细胞肺癌细胞株抗癌药物敏感性相关基因差异表达的初步研究

背景与目的为了提高晚期肺癌的化疗效果，实行个体化治疗，筛选和鉴定肺癌细胞抗癌药物敏感性基因具有重要临床意义。本研究比较了非小细胞肺癌(NSCLC)和永生化人支气管上皮细胞(BET2A)细胞株抗癌药物敏感性相关基因的差异表达，以寻找与抗癌药物敏感性相关的基因。方法应用cDNA macroarray技术，对6株NSCLC和BET2A细胞株的抗癌药物敏感性相关基因进行差异表达分析，RT-PCR技术验证滤膜杂交结果。结果在1291个候选基因中筛选出73个差异表达基因，其中45个基因表达上调，28个基因表达下调。RT-PCR验证结果与cDNA macroarray检测结果一致。结论抗癌药物敏感性相关基因的差异表达可能是药物敏感性产生不同的原因之一。本研究结果为逆转肺癌多药耐药性提供了理论基础和新靶点，并为临床新药开发及个体化治疗提供了实验依据。     

Identification of candidate predictive markers of anticancer drug sensitivity using a panel of human cancer cell lines

We previously investigated the correlations between the expression of 9216 genes and various chemosensitivities in a panel of 39 human cancer cell lines¹⁾ and found that the expression levels of AKR1B1 and CTSH were correlated with sensitivity and resistance to multiple drugs, respectively. To validate these correlations, we investigated the expression of these two genes and the chemosensitivities in 12 additional gastric cancer cell lines. The expression of AKR1B1 in the additional cell lines exhibited significant correlations with sensitivities to 8 of the 23 drugs examined, while that of CTSH displayed a significant negative correlation with only one (MS-247) of the 27 drugs examined. Their expressions were weakly correlated with sensitivity and resistance, respectively, to the remainder of the drugs. Moreover, when the 12 cell lines were divided into high-expressing and low-expressing groups, a comparison of these groups using Mann-Whitney's U test revealed that high expression levels of AKR1B1 and CTSH were related to sensitivity to 21 of the drugs and resistance to 8 of the drugs, respectively. The present results suggest that AKR1B1 and CTSH may be good markers for prediction of sensitivity to certain drugs and that our panel of 39 cell lines has the potential to identify candidate predictive marker genes.     

Differential cytotoxicity of 19 anticancer agents in wild type and etoposide resistant small cell lung cancer cell lines.

A panel of six ''wild type'' and three VP-16 resistant small cell lung cancer (SCLC) cell lines is used to evaluate to what extent in vitro sensitivity testing using a clonogenic assay can contribute to combine cytotoxic drugs to regimens with improved efficacy against SCLC. The resistant lines include (a) H69/DAU4, which is classical multidrug resistant (MDR) with a P-glycoprotein efflux pump (b) NYH/VM, which exhibits an altered topoisomerase II (topo II) activity and (c) H69/VP, which is cross-resistant to vincristine, exhibits a reduced drug accumulation as H69/DAU4 but is without P-glycoprotein. 19 anticancer agents were compared in the panel. The MDR lines demonstrated, as expected, cross-resistance to all topo II drugs, but also different patterns of collateral sensitivity to BCNU, cisplatin, ara-C, hydroxyurea, and to the topo I inhibitor camptothecin. The complete panel of nine cell lines clearly demonstrated diverse sensitivity patterns to drugs with different modes of action. Correlation analysis showed high correlation coefficients (CC) among drug analogues (e.g. VP-16/VM-26 0.99, vincristine/vindesine 0.89), and between drugs with similar mechanisms of action (e.g. BCNU/Cisplatin 0.89, VP-16/Doxorubicin 0.92), whereas different drug classes demonstrated low or even negative CC (e.g. BCNU/VP-16 -0.21). When the CC of the 19 drug patterns to VP-16 were plotted against the CC to BCNU, clustering was observed between drugs acting on microtubules, on topo II, alkylating agents, and antimetabolites. In this plot, camptothecin and ara-C patterns were promising by virtue of their lack of cross-resistance to alkylating agents and topo II drugs. Thus, the differential cytotoxicity patterns on this panel of cells can (1) give information about drug mechanism of action, (2) enable the selection and combination of non-cross-resistant drugs, and (3) show where new drugs ''fit in'' among established agents.     

Cyclooxygenase-2 inhibitor induces apoptosis and enhances cytotoxicity of various anticancer agents in non-small cell lung cancer cell lines.

In recent years, a combination of two demographic phenomena, an increase in the number of older people in the population and an increase in the incidence of lung cancer with age, has made it mandatory to develop therapeutic modalities with less toxicity for the treatment of inoperable elderly patients with lung cancer. Our study shows that a cyclooxygenase (COX)-2 inhibitor, nimesulide, can inhibit proliferation of non-small cell lung cancer cell lines in vitro in a dose-dependent manner, in part by inducing apoptosis even at clinically achievable low concentrations. Our observations also suggest that the responsiveness of non-small cell lung cancer to COX-2 inhibitors does not require the presence of wild-type p53, but may be influenced by the degree of COX-2 expression. In addition, we found that nimesulide, when used in combination at clinically achievable concentrations, reduced the IC50 values of various anticancer agents by up to 77%, although the level of reduction varied considerably. Because our previous studies have indicated a significantly increased COX-2 expression in up to 70% of adenocarcinoma cases, the present findings are of great clinical interest. In conjunction with the recent development of next generation, highly selective COX-2 inhibitors, they can be expected to lead to even greater efficacy of their use as adjuncts to various anticancer agents for the treatment of high-risk patients without compromising their quality of life.     

肺癌细胞株中顺铂药物敏感性的相关基因

目的 筛选小细胞肺癌(SCLC)和非小细胞肺癌(NSCLC)细胞株中与顺铂(DDP)药物敏感性相关的基因.方法 采用二苯基溴化四氮唑蓝(MTT)比色分析法,测定4株SCLC细胞株和6株NSCLC细胞株对DDP的药物敏感性;应用cDNA微阵列技术检测肺癌细胞株中1291个药物敏感性相关基因的表达状态,并分析基因表达与DDP敏感性之间的相关性.结果 Metallothionein、Cathepsin B、TIMP1、TNF-R1、TGFβ-induced 68000、Cathepsin L、Galectin-1、Annexin 11、PAI-1、IGFBP4、UPAR、Jagged、CD13、α1 A-AR、EphA2(Eek)、APC、RhoC、Fibromodulin、GATA-6、HSC 70共20个基因,在SCLC和NSCLC细胞株中均与DDP的药物敏感性呈负相关,只有Procoagula和MDM2与DDP的敏感性呈正相关.VHL、MMP-7、Elongin A、GSK-3β、SLC、Galectin-3、Integrinβ5、Moesin、IKKβ和ETV 1等10个基因,只在SCLC细胞株中与DDP的药物敏感性呈负相关,而AT2与DDP敏感性呈正相关.Clusterin、FG FR-2、Thrombospondin 1、HSP 32、Lactate dehydrogenase A、P300、Thymosinβ10、CD81、C/EBPγ和Rak等10个基因,只在NSCLC细胞株中与DDP的药物敏感性呈负相关,而只有CaMKK和TPA与DDP的敏感性呈正相关.结论 与DDP药物敏感性相关的基因共有45个,其中共同表达于SCLC和NSCLC细胞株中的基因有22个,在SCLC细胞株中特异表达的基因有11个,在NSCLC细胞株中特异表达的基因有12个.     

Validation of predictive models for germline mutations in DNA mismatch repair genes in colorectal cancer

Lynch syndrome is defined by the presence of germline mutations in mismatch repair (MMR) genes. Several models have been recently devised that predict mutation carrier status (Myriad Genetics, Wijnen, Barnetson, PREMM and MMRpro models). Families at moderate‐high risk for harboring a Lynch‐associated mutation, referred to the BC Cancer Agency (BCCA) Hereditary Cancer Program (HCP), underwent mutation analysis, immunohistochemistry and/or microsatellite testing. Seventy‐two tested cases were included. Twenty‐five patients were mutation positive (34.7%) and 47 were mutation negative (65.3%). Nineteen of 43 patients who were both microsatellite stable and normal on immunohistochemistry for MLH1 and MSH2 were also genotyped for mutations in these genes; all 19 were negative for MMR gene mutations. Model‐derived probabilities of harboring a MMR gene mutation in the proband were calculated and compared to observed results. The area under the ROC curves were 0.75 (95%CI; 0.63–0.87), 0.86 (0.7–0.96), 0.89 (0.82–0.97), 0.89 (0.81–0.98) and 0.93 (0.86–0.99) for the Myriad, Barnetson, Wijnen, MMRpro and PREMM models, respectively. The Amsterdam II criteria had a sensitivity and specificity of 0.76 and 0.74, respectively, in this cohort. The PREMM model demonstrated the best performance for predicting carrier status based on the positive likelihood ratios at the >10%, >20% and >30% probability thresholds. In this referred cohort, the PREMM model had the most favorable concordance index and predictive performance for carrier status based on the positive LR. These prediction models (PREMM, MMRPro and Wijnen) may soon replace the Amsterdam II and revised Bethesda criteria as a prescreening tool for Lynch mutations.     

Doxorubicin-induced apoptosis and chemosensitivity in hepatoma cell lines

PURPOSE: Doxorubicin (DOX) is a commonly used anticancer drug which causes DNA damage and kills cancer cells mainly by apoptosis. However, the process leading to killing of cancer cells and the molecular basis of resistance to DOX are not well understood. To evaluate the role of p53 and the cellular effects of DOX on hepatoma cell lines, we examined three hepatoma cell lines with different p53 status--Huh-7 (mutated p53), HepG2 (wild-type p53) and Hep3B (deleted p53). METHODS: The chemosensitivity of the three hepatoma cell lines was assessed using the MTT assay, and cell cycle distribution was evaluated by flow cytometry. Western blotting and immunostaining were employed to examine the protein alterations in response to DOX treatment, and a DNA fragmentation assay was performed to detect apoptosis. RESULTS: Of the three cell lines, HepG2 was found to be most resistant to DOX, followed by Hep3B, and Huh-7 was most sensitive to DOX treatment. HepG2 showed G1 arrest 24 h after drug administration and upregulation of p53 protein level in a time-dependent manner. In Hep3B cells (deleted p53), G2/M phase arrest was observed soon after drug administration, accompanied by induced apoptosis that was p53-independent. In Huh-7 cells (mutated p53), which were most sensitive to DOX, there was neither G1 nor G2 arrest, and the level of p53 mutated protein was downregulated after DOX treatment. MDM2 and p27 proteins were downregulated in all cell lines independently of p53 status. p21 was upregulated following p53 activation at low doses of DOX in HepG2 cells, but at higher doses, p21 was downregulated in Huh-7 and HepG2 cells. CONCLUSION: DOX confers different chemosensitivity on different hepatoma cell lines with different p53 status. The contrasting relationships between chemosensitivity and p53 status and expression suggest that DOX-induced apoptosis and cell death involve pathways that are independent of p53.     

Clinical usefulness of chemosensitivity test for advanced colorectal cancer

We assessed the usefulness of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay in the evaluation of appropriate adjuvant cancer chemotherapy for patients with advanced colorectal cancer. We analyzed 405 cases of colorectal cancer treated between January 1990 and August 1999 in terms of the MTT assay and survival outcome. Patients with Dukes' C and D were classified into a "surgery alone" group (n = 53), a "sensitive" group who received drugs that had a greater than 50% inhibition rate by MTT assay (n = 23), or "resistant" group who were insensitive to the chemotherapy drugs (n = 124). Statistically significant differences in survival outcome were observed between the groups, with the sensitive group showing significantly better survival compared with the resistant group (p = 0.0158) and the surgery-alone group (p = 0.0004). Our results suggest that the MTT assay may be useful in evaluating the optimum adjuvant chemotherapy for patients with advanced colorectal cancer.     

ＡＴＰ生物荧光体外药敏检测在中晚期结直肠癌化疗药物筛选中的应用

目的　探讨ＡＴＰ生物荧光体外药敏检测法（ＡＴＰ-ＴＣＡ）的特点及其在中晚期结直肠癌患者化疗方案中的指导价值。方法　应用ＡＴＰ-ＴＣＡ体外检测５９例结直肠癌细胞对常用抗癌药物的敏感性。结果　ＡＴＰ-ＴＣＡ法对结直肠癌标本的可评估率为９６.６１％。５７例结直肠癌细胞对４组联合化疗药物氟尿嘧啶＋丝裂霉素、氟尿嘧啶＋奥沙利铂、氟尿嘧啶＋伊立替康、氟尿嘧啶＋奥沙利铂＋伊立替康相比氟尿嘧啶、丝裂霉素、伊立替康、奥沙利铂４种单药的敏感度有高度显著性差异（Ｐ＝０.０００６）。应用ＡＴＰ-ＴＣＡ检测结果指导中晚期结直肠癌患者化疗,临床近期有效率为５９.６５％（３４／５７）,总预测准确率为６３.１６％（３６／５７）,阳性符合率为６１.８２％（３４／５５）,阴性符合率为１００％（２／２）。结论　ＡＴＰ-ＴＣＡ能有效检测化疗药物的敏感性,对指导中晚期结直肠癌患者化疗有重要的临床意义。     

大肠癌培养细胞p53存在状态与化疗敏感性

目的　探讨人大肠癌培养细胞p5 3存在状态与化疗敏感性的相关性。方法　应用p5 3机能诊断法 ,确认 6株人大肠癌培养细胞p5 3的存在状态 ,以MTT方法比较了p5 3野生型和突变型两组肠癌细胞对化疗敏感性的差异 ,用流式细胞仪做细胞周期的进一步分析。结果　p5 3野生型肠癌细胞较p5 3突变型细胞的化疗敏感性高 5～ 10倍 ,并且在化疗药阿霉素诱导下可选择地发生细胞凋亡和G1阻滞。结论　人体大肠癌培养细胞p5 3存在状态直接与其化疗敏感性有关。