Effects of transferred NK4 gene on proliferation, migration, invasion and apoptosis of human prostate cancer DU145 cells

We investigated the ability of NK4, an antagonist of human hepatocyte growth factor （HGF）, to inhibit the influence of HGF on proliferation, migration, invasion and apoptosis of human prostate cancer cells. Expression vector pBudCE4.1-EGFP-NK4 containing NK4 cDNA was used to transfect human prostate cancer DU145 cells, and the effects of the autocrine NK4 on tumor cell proliferation, migration, invasion and apoptosis were assessed in vitro. in vivo, we subcutaneously implanted DU145 cells, mock-transfected clone （DU145/empty vector） cells and NK4- transfected clone （DU145/NK4） cells into nude mice, and then evaluated tumor growth, cell proliferation and cell apoptosis in vivo. We found that DU145/NK4 cells expressed NK4 protein. In the in vitro study, autocrine NK4 at- tenuated the HGF-induced tumor cell proliferation, migration and invasion, and stimulated apoptosis. Furthermore, autocrine NK4 effectively inhibited the HGF-induced phosphorylation of c-Met, extracellular signal-regulated kinase-1 （ERK1）. and protein kinase B 1/2 （Aktl/2）. Histological examination revealed that autocrine NK4 inhibited prolifera- tion and accelerated apoptosis of prostate cancer cells. These results show that genetic modification of DU145 cells with NK4 cDNA yields a significant effect on their proliferation, migration, invasion and apoptosis. Molecular targeting of HGF/c-Met by NK4 could be applied as a novel therapeutic approach to prostate cancer.

Inhibition of telomerase with human telomerase reverse transcriptase antisense increases the sensitivity of tumor necrosis factor-α-induced apoptosis in prostate cancer cells

Aim： To investigate the effect of inhibition of telomerase with human telomerase reverse transcriptase （hTERT） antisense on tumor necrosis factor-α （TNF-α-induced apoptosis in prostate cancer cells （PC3）. Methods： Antisense phosphorothioate oligodeoxynucleotide （AS PS-ODN） was synthesized and purified. Telomerase activity was measured using the telomeric repeat amplification protocol （TRAP） and polymerase chain reaction enzyme-linked immunoassay （PCR-ELISA）. hTERT mRNA was measured by reverse transcription PCR （RT-PCR） assay and gel-image system, hTERT protein was detected by immunochemistry and flow cytometry. Cell viability was detected by 3-（4, 5-dimethylthiazol-2-yl）-2,5-Diphenyltetrazolium （MTT） assay. Cell apoptosis was observed by morphological method and determined by flow cytometry. Results： The telomerase activity decreased with time after hTERT AS PS-ODN treatment. The levels of hTERT mRNA decreased with time after hTERT AS PS-ODN treatment, which appeared before the decline of the telomerase activity. The percentage of positive cells of hTERT protein declined with time after hTERT AS PS-ODN treatment, which appeared after the decline of hTERT mRNA. There was no difference in telomerase activity, hTERT mRNA and protein levels between hTERT sense phosphorothioate oligodeoxynucleotide （S PS-ODN） and the control group. The cell viability decreased with time after hTERT AS PS-ODN combined with TNF-α treatment. The percentage of apoptosis increased with time after hTERT AS PS-ODN combined with TNF-α treatment. There was no difference in cell viability and the percentage of apoptosis between hTERT S PS-ODN and the control group. Conclusion： hTERT AS PS-ODN can significantly inhibit telomerase activity by downregulating the hTERT mRNA and protein expression, and inhibition of telomerase with hTERT antisense can enhance TNF-α- induced apoptosis of PC3 cells.

Signal Transduction Pathways Mediated by Secreted and Non-Secreted Forms of Intact Insulin-Like Growth Factor Binding Protein-3 (IGFBP-3) and Its 1-97 N-Terminal Fragment in PC-3 Human Prostate Cancer Cells

Our previous results indicated that both the secreted and the intracellular form of full length and 1-97 N-terminal fragment of IGFBP-3 induce apoptosis in PC-3 human prostate cancer cells in an IGF-dependent and independent manner. This study was undertaken to delineate possible down-stream signaling pathways that are involved in this process. Intact IGFBP-3 and its N-terminal 1-97 fragments with or without a signal propeptide were fused to YFP and expressed in PC-3 human prostate cancer cells. In some cases, the putative IGF-binding site was presented in full length IGFBP-3 and its N-terminal fragment was also mutated. Extent of apoptosis was quantified using FACS. Up-regulation of total Stat-1 and activation of phospho-Stat-1 were shown by western blot. TGF-β signal was measured by luciferase reporter assay. Results from inhibitor studies indicated that both the Caspase 8 and caspase 9 pathways are involved in IGFBP-3 (non-secreted form) which induced apoptosis in PC-3 cells. Exogenous addition of IGFBP-3 to PC-3 cells increased Stat-1 protein expression/tyrosine phosphorylation. Interestingly, results also showed that knockdown of Stat-1 by siRNA potentiated the IGFBP-3 induced apoptosis in PC-3 cells. In addition, both full-length IGFBP-3 and its 1-97 Nterminal fragments inhibited TGF-β signaling in these cells. This is the first report that compares the signal transduction pathways involved in apoptotic pathways mediated by IGFBP-3 in PC-3 human prostate cancer cells. Non-secreted form of full length IGFBP-3 and its N-terminal fragments induced apoptosis in PC-3 cells via activation of caspase 8 and caspase 9. Although, only non-secreted form of IGFBP-3 is involved in inducing apoptosis in PC-3 cells via caspase 8 and caspase 9 activation pathways but both secreted and non-secreted forms of IGFBP-3 are involved in modulating Stat-1 and TGF-β pathways to induce apoptotic actions in PC-3 cells. Non-secreted intact IGFBP-3 and its N-terminal fragments induced apoptosis in PC-3 cells via activation of caspase 8 and caspase 9 pathways. Modulation in STAT-1 and TGF-β pathways may also be important for IGFBP-3 induced apoptosis in PC-3 cells in general. These studies clearly demonstrate that secreted and non-secreted FL and 1-97 N-terminal fragments induce apoptosis in PC-3 cells by regulating different mechanistic pathways.

Induction of Apoptosis in the Human Prostate Cancer Cell Line DU-145 by a Novel Micronutrient Formulation

Prostate cancer, the most frequently diagnosed cancer in men, primarily affects males aged 55 and older and is more common in African Americans than Caucasians. Once the cancer has metastasized, current treatments are generally ineffective. We have identified a novel anti-neoplastic agent, a specifically designed nutrient mixture (NM), containing ascorbic acid, lysine, proline and green tea extract that demonstrates a broad spectrum of anti-tumor activity against a number of human cancer cell lines. In a previous study NM significantly inhibited prostate tumor in nude mice. In this study, we tested whether the formulation exerts its anti-tumor effects through induction of apoptosis on prostate cancer cell line DU-145. The effect of the nutrient mixture (NM) on cell growth inhibition in DU-145 cells was examined by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Morphological changes and caspase activation associated with apoptosis induction was checked by H&E staining and Live Green Caspase assay, respectively. The NM was found to be slightly toxic to DU-145 cells at 100 μg/ml, but significantly toxic at 500 μg/ml and 1000 μg/ml. Percentage of cells undergoing apoptosis also increased from 6% at 100 μg/ml to 49% at 500 μg/ml and 83% at 1000 μg/ml, with greater number of cells showing morphological changes such as condensed nuclei and an acidophilic cytoplasm at higher concentrations. For the purpose of comparison, NM was also tested on a normal human dermal fibroblast (NHDF) cell line which exhibited far less apoptosis induction as compared to DU-145 cells. The percentage of cells undergoing apoptosis in case of NHDF cells was 7% at 100 μg/ml, 25.6% at 500 μg/ml and 76.5% at 1000 μg/ml. Our results demonstrate that the NM is effective in inhibiting cancer cell viability and inducing apoptosis in prostate cancer DU-145 cells and can thus be used as an effective treatment for prostate cancer.

Loss of the vitamin D receptor in human breast and prostate cancers strongly induces cell apoptosis through downregulation of Wnt/β-catenin signaling

Vitamin D co-regulates cell proliferation, differentiation and apoptosis in numerous tissues, including cancers. The known anti-proliferative and pro-apoptotic actions of the active metabolite of vitamin D, 1,25-dihydroxy-vitamin D [1,25（OH）2D] are mediated through binding to the vitamin D receptor （VDR）. Here, we report on the unexpected finding that stable knockdown of VDR expression in the human breast and prostate cancer cell lines, MDA-MB-231 and PC3, strongly induces cell apoptosis and inhibits cell proliferation in vitro. Implantation of these VDR knockdown cells into the mammary fat pad （MDA-MB-231）, subcutaneously （PC3） or intra-tibially （both cell lines） in immune-incompetent nude mice resulted in reduced tumor growth associated with increased apoptosis and reduced cell proliferation compared with controls. These growth-retarding effects of VDR knockdown occur in the presence and absence of vitamin D and are independent of whether cells were grown in bone or soft tissues. Transcriptome analysis of VDR knockdown and non-target control cell lines demonstrated that loss of the VDR was associated with significant attenuation in the Wnt/0-catenin signaling pathway. In particular, cytoplasmic and nuclear β-catenin protein levels were reduced with a corresponding downregulation of downstream genes such as Axin2, Cyclin D1, interleukin-6 （IL-6）, and IL-8. Stabilization of 0-catenin using the GSK-3β inhibitor BIO partly reversed the growth-retarding effects of VDR knockdown. Our results indicate that the unliganded VDR possesses hitherto unknown functions to promote breast and prostate cancer growth, which appear to be operational not only within but also outside the bone environment. These novel functions contrast with the known anti-proliferative nuclear actions of the liganded VDR and may represent targets for new diagnostic and therapeutic approaches in breast and prostate cancer.

黄鱼鱼鳔肽分离及其诱导前列腺癌DU-145细胞凋亡的机制

为探讨黄鱼鱼鳔肽诱导前列腺癌DU-145细胞凋亡的作用机制,从黄鱼鱼鳔酶解产物中分离纯化得到鱼鳔肽,鉴定其氨基酸序列。采用CCK-8法检测鱼鳔肽作用后DU-145细胞抑制率的变化;AO/EB法检测DU-145细胞凋亡情况;流式细胞术检测DU-145细胞凋亡率和周期;免疫印记法检测DU-145细胞凋亡蛋白表达。结果表明,分离得到的鱼鳔肽YCSB-1c中包含Ser-Pro-Ser-Pro和Gly-Pro-Ala-Arg两条寡肽。与空白组相比,YCSB-1c组中凋亡细胞明显增多,且呈质量浓度依赖性;流式细胞仪检测得出YCSB-1c组中存活细胞明显减少,晚期凋亡细胞明显增多。YCSB-1c将DU-145细胞的细胞周期阻滞在G0/G1期,上调Bax、Caspase-3及Caspase-9蛋白表达,诱导DU-145细胞凋亡。YCSB-1c能有效诱导DU-145细胞凋亡,其作用机制与细胞周期停滞和线粒体介导的凋亡途径有关。

芪蓝方对人前列腺癌DU145细胞增殖和凋亡的作用机制研究

目的:观察芪蓝方对人前列腺癌DU145细胞增殖和凋亡的影响,并探讨其作用机制。方法:以DU145细胞为研究对象,通过观察不同浓度芪蓝方组(400、200、100、50、25、12.5、6.25、3.125、1.56、0μg/ml)细胞形态变化,筛选出高、中、低浓度应用于后续实验,并采用CCK-8法检测DU145细胞增殖,流式细胞术检测DU145细胞周期、凋亡情况,Western印迹检测DU145细胞中细胞周期、凋亡相关蛋白Cyclin D1、Bax、Bcl-2、Cleaved-Caspase 3的表达。结果:筛选结果显示100、200、400μg/ml浓度的芪蓝方均能显著抑制DU145细胞的生长、降低轮廓清晰度和贴壁能力,且200、400μg/ml浓度的芪蓝方可显著降低DU145细胞活力,故确定高中低浓度为400、200、100μg/ml,并用于后续实验研究。与空白组比较,G2期各浓度组DU145细胞数显著增加(P<0.01),而S期高、中浓度组细胞数显著下降(P<0.01、P<0.05);与空白对照组相比,芪蓝方各组DU145细胞总凋亡数均显著增高(P<0.01),高浓度组Cyclin D1表达显著降低,高、中浓度组Bcl-2表达明显降低,Bax和Cleaved-Caspase 3表达水平明显上升(P均<0.01)。结论:芪蓝方能够抑制前列腺癌DU145细胞的细胞增殖,促进其细胞凋亡,其机制可能与下调细胞周期相关蛋白Cyclin D1表达,破坏Bax/Bcl-2平衡,上调Cleaved-Caspase 3表达相关。

Inhibitory effect of a new gossypol derivative apogossypolone (ApoG2) on xenograft of human prostate cancer cell line PC-3

Objective: To investigate the inhibitory effect of apogossypolone (ApoG2) on prostate cancer cell line PC-3 in vivo, and explore its mechanism. Methods: The models of transplantation tumors in Balb/c nu/nu mice were established via subcutaneous injection of PC-3 cells and the tumor-transplanted mice were divided into 4 groups: control group and three ApoG2 treatment groups, with 10 mice in each group. Volumes of the tumor were estimated every 2 d and the morphology of tumor tissues was observed. Immunohistochemistry was employed to observe the expression of Bcl-2, PCNA, CD31, caspase-3 and caspase-8 in tumor tissues. Results: ApoG2 (2.5 mg/kg-10 mg/kg) given intraperitoneally once a day can obviously inhibit the growth of subcutaneous prostatic carcinoma implant. The tumor volume decreased obviously when the treatment dosage was bigger than 5.0 mg/kg (P<0.01). Meanwhile, ApoG2 decreased the expression of PCNA and CD31, and enhanced the expression of caspases-3, caspase-8 in tumor tissues. Conclusion: ApoG2 exert an inhibitory effect on prostatic carcinoma possibly by inducing apoptosis and inhibiting tumor angiogenesis.

A Comparative Study on Proteomics between LNCap and DU145 Cells by Quantitative Detection and SELDI Analysis

The differences in intracellular and extracellular protein expressions between human prostate cancer lines LNCap and DU145 were examined, The proteins of the two cell lines were extracted and condensed by using protein extraction kits. And the intracellular and extracellular proteins were quantitatively detected on a micro-plate reader by using bicinchoninic acid （BCA） method. The proteins in cell culture fluid were qualitatively assayed by SELDI-TOF-MS, The results showed that the intracellular protein contents of LNCap cells were extremely higher than those of DU145 cells. After serum-free culture, both intracellular and extracellular protein contents of LNCap and DU145 were decreased to some extent. And the intracellular proteins were decreased by 5% in LNCap and by 36% in DU145 respectively, while the extracellular proteins were decreased by 89% in LNCap and 96% in DU145 respectively. SELDI assay revealed that there were 5 marker proteins in LNCap and 6 in DU145. Although both LNCap and DU145 cell lines originated from human prostate cancer, they had some differences in protein expression.

番茄红素对人前列腺癌细胞(DU145)生长抑制的离体和整体水平研究

目的 研究番茄红素对人前列腺癌细胞DU145的影响。方法 体外培养的人前列腺癌细胞DU145经番茄红素作用后用苔盼蓝染色进行活细胞计数 ,绘制生长曲线并计算抑制率 ;应用流式细胞仪分析番茄红素对DU145细胞周期和凋亡的影响。制作裸鼠人前列腺癌模型 ,观察番茄红素在整体动物上的作用。结果 番茄红素可以明显抑制DU145细胞的生长 ,且呈剂量 效应和时间 效应关系。 10、2 0、40 μmol L处理细胞 7d后 ,细胞增长的抑制率分别为 10 76 %、92 90 %、99 11% (P <0 0 1)。裸鼠人前列腺癌模型上的研究显示 ,6 %番茄红素油树脂可显著抑制腺瘤的生长 ,30 0mg kg剂量组腺癌抑制率可达到 75 76 % (P <0 0 5 )。用经番茄红素处理过的细胞致瘤力消失。流式细胞仪分析显示番茄红素可影响该细胞周期并引起细胞凋亡 ,凋亡率高达 42 42 %。结论 番茄红素可以在离体细胞和整体动物水平明显抑制雄激素非依赖型人前列腺癌DU 145 ,其抑制机制可能是通过影响人前列腺癌细胞的生长周期和诱导其凋亡而实现。

鸦胆子苦醇抑制人前列腺癌DU145细胞生长及作用机制

中药鸦胆子是一种常用的抗肿瘤中草药,鸦胆子苦醇是来源于鸦胆子的主要成分。该研究探讨了鸦胆子苦醇(brusatol)对人前列腺癌DU145细胞的生长抑制及其作用机制。采用四甲基偶氮唑盐(MTT)法检测鸦胆子苦醇对不同细胞株的生长抑制情况,以及不同浓度的鸦胆子苦醇对DU145细胞的增殖抑制率;应用Hoechst 33258染色法观察鸦胆子苦醇处理DU145细胞后所发生的形态学变化;分别采用PI单染及AnnexinV-FITC双染法流式细胞术分析细胞周期分布个凋亡率的变化;以Western blot测定鸦胆子苦醇对MAPK信号通路相关蛋白表达的影响。结果表明:鸦胆子苦醇对人前列腺癌DU145细胞的抑制作用更为显著,并且可以时间和剂量依赖性地抑制人前列腺癌DU145细胞的生长,其半数有效抑制浓度IC50为(0.27±0.04)μmol·L-1;鸦胆子处理DU145细胞后,Hoechst 33258染色可见到明显的凋亡特征;细胞周期图中可见明显的亚二倍体峰,且随着作用时间的延长凋亡比例增加,FCM检测鸦胆子苦醇作用24 h后凋亡图中,可见凋亡的发生;Western blot检测表明鸦胆子苦醇处理后可使磷酸化的p38和JNK表达增加,使磷酸化的ERK表达降低。鸦胆子苦醇能显著抑制DU145细胞增殖,诱导DU145细胞凋亡。磷酸化的P38和JNK的表达增加,但磷酸化的ERK表达下降,这表明MAPK途径的活化可能是鸦胆子苦醇对DU145细胞生长抑制的作用机制之一。因此,鸦胆子苦醇是潜在的抗前列腺癌药物,有必要进一步在动物水平阐明其抗前列腺癌活性。

低剂量壬基酚促进DU-145细胞增殖及雌激素膜受体GPR30表达的研究

目的:观察低剂量外源性雌激素壬基酚(NP)对人前列腺癌细胞株DU-145增殖和雌激素膜受体GPR30表达的影响。方法:DU-145细胞暴露于不同浓度的NP,通过细胞增殖实验测定DU-145细胞的半数抑制率(IC50),确定低剂量NP的暴露浓度范围;CCK-8实验测定低剂量NP对细胞增殖的影响;RT-PCR法观察DU-145细胞中3种雌激素受体(ER),ER-α、ER-β和雌激素膜受体GPR30的表达水平以及低剂量NP暴露后,雌激素膜受体GPR30表达的变化。结果:NP抑制细胞增殖的IC50为46μmol/l,确定本实验中使用的低剂量NP浓度分别为0.01、0.1、1μmol/l;CCK-8的结果发现,低剂量NP对DU-145细胞具有促增殖作用。RT-PCR的结果发现,DU-145细胞中有3种ER的表达,与前列腺上皮细胞表达类似,低剂量NP具有促GPR30表达的作用。结论:雌激素膜受体GPR30可能在介导低剂量NP促前列腺癌细胞DU-145增殖的过程中起到一定作用。

基于TGF-β/Smads信号传导通路探讨姜黄素抑制前列腺癌DU-145细胞增殖的机理

目的:基于TGF-β/Smads信号传导通路,观察中药提取物姜黄素对人雄激素非依赖性前列腺癌DU-145细胞的影响,从而探讨姜黄素抑制DU-145细胞增值的机理。方法:分别用12.5、6.25以及3.125μmol/L姜黄素作用DU-145细胞48 h后,光镜观察细胞形态变化,以MTT法检测DU-145细胞生长情况,以RT-PCR法检测TGF-β,Smad2,Smad4和Smad7基因表达情况。结果:姜黄素能显著抑制DU-145细胞生长,呈一定的量效关系;RT-PCR法检测DU-145细胞TGF-β,Smad2和Smad4基因表达均不同程度增加,而Smad7的基因表达不同程度减少。结论:姜黄素通过对TGF-β及下游蛋白Smad2、Smad4、Smad7的影响,进而调节TGF-β/Smads信号传导通路,这可能是姜黄素促进DU-145细胞凋亡和抑制其生长的重要分子机制。

蟾毒灵对人雄激素非依赖性前列腺癌DU145细胞增殖及Bcl-2、Bax基因的影响

目的:研究蟾毒灵(bufalin,Bu)对人雄激素非依赖性前列腺癌DU145细胞增殖及凋亡相关基因Bcl-2、Bax的影响。方法:CCK-8法检测细胞抑制效应,光学显微镜观察细胞形态变化,流式细胞术检测药物诱发细胞凋亡改变,Western-blot法检测细胞凋亡相关基因Bcl-2、Bax的表达。结果:CCK-8法检测提示蟾毒灵处理细胞后有显著的增殖抑制作用;光学显微镜观察显示细胞增殖受到抑制并呈凋亡形态改变;流式细胞术检测结果表明,蟾毒灵诱导DU145细胞凋亡、凋亡率与对照组比较,差异有统计学意义(P<0.05);Western-blot检测提示蟾毒灵可增强细胞Bax基因的表达,下调Bcl-2基因的表达。结论:蟾毒灵能抑制人前列腺癌DU145细胞增殖,其机制可能与蟾毒灵调控细胞凋亡效应有关。

莪术醇通过调节lncRNA NR2F1-AS1/miR-145-5p表达抑制前列腺癌细胞增殖及转移

目的:探讨莪术醇对前列腺癌细胞增殖及转移的影响及其可能作用机制。方法:不同浓度的莪术醇处理人前列腺癌细胞LNCap,采用脂质体转染法将si-NC、si-lncRNA NR2F1-AS1分别转染至LNCap细胞,将pcDNA、pcDNA-lncRNA NR2F1-AS1分别转染至LNCap细胞后加入100μg/ml莪术醇处理;CCK-8法、平板克隆形成实验、Transwell实验分别检测细胞增殖、克隆形成、迁移及侵袭;qRT-PCR检测lncRNA NR2F1-AS1、miR-145-5p表达量;双荧光素酶报告实验验证lncRNA NR2F1-AS1与miR-145-5p的靶向关系。结果:莪术醇可降低细胞存活率,并可降低lncRNA NR2F1-AS1表达量,克隆形成数、迁移及侵袭细胞数减少(P<0.05),而miR-145-5p表达量升高(P<0.05);lncRNA NR2F1-AS1可靶向调控miR-145-5p的表达(P<0.05);转染si-lncRNA NR2F1-AS1后细胞存活率降低(P<0.05),miR-145-5p表达量升高(P<0.05),克隆形成数、迁移及侵袭细胞数减少(P<0.05);转染pcDNA-lncRNA NR2F1-AS1可降低莪术醇对LNCap细胞增殖及转移的作用。结论:莪术醇可通过调节lncRNA NR2F1-AS1/miR-145-5p表达,抑制前列腺癌细胞增殖、克隆形成、迁移及侵袭。

miR-17-92基因簇增强前列腺癌DU145细胞的迁移、侵袭能力及对顺铂的耐药性

背景与目的:mi R-17-92基因簇与多种疾病的发生密切相关,其在肺癌、肝癌、胃癌和前列腺癌等多种肿瘤细胞中均高表达。本研究利用慢病毒包装系统建立稳定高表达mi R-17-92基因簇的DU145细胞株,探讨mi R-17-92基因簇对前列腺癌DU145细胞的迁移、侵袭能力及对顺铂耐药性的影响。方法:构建高表达mi R-17-92基因簇的表达载体,转染DU145细胞株,同时转染空载体作为对照,并用实时荧光定量聚合酶链反应(real-time fluorescent quantitative polymerase chain reaction,RTFQ-PCR)进行鉴定。用x CELLigence系统监测细胞的迁移、侵袭能力及顺铂处理后的生长情况;通过划痕实验观察细胞的迁移情况;采用蛋白[质]印迹法(Western blot)、凝胶酶谱实验和RTFQ-PCR检测相关蛋白质和基因的表达以探讨mi R-17-92增强DU145细胞的迁移、侵袭能力及对顺铂耐药性的相关机制。结果:DU145-mi R-17-92细胞迁移速率和侵袭能力高于DU145-control细胞(P<0.01)。DU145-mi R-17-92细胞中整合素β1的蛋白质表达水平和基质金属蛋白酶-9(matrix metalloprotein-9,MMP-9)的活性显著高于DU145-control细胞。顺铂处理后,DU145-mi R-17-92细胞的生长速度自12 h起快于DU145-control细胞并呈顺铂耐药性(P<0.01)。细胞外调节蛋白激酶1/2(extracellular regulated protein kinases,ERK1/2)在DU145-mi R-17-92细胞中呈现持续高水平磷酸化,顺铂处理后,其磷酸化水平无明显变化。DU145-mi R-17-92细胞中切除修复互补交叉基因1(excision repair cross complementing1,ERCC1)的m RNA和蛋白质表达水平显著高于DU145-control细胞。结论:高表达mi R-17-92增强了DU145细胞的迁移、侵袭能力,其机制与整合素β1的表达上调及MMP-9活性增强有关。此外,高表达mi R-17-92增强了DU145细胞对顺铂的耐药性,该过程与ERK1/2的磷酸化水平增加和ERCC1的表达水平上调相关。

比卡鲁胺联合重组人瘦素拮抗剂对前列腺癌DU-145细胞增殖及凋亡的影响

目的为比卡鲁胺联合重组人瘦素拮抗剂治疗对前列腺癌提供理论依据。方法重组人瘦素诱导体外培养DU-145细胞后,分别采用1、2、5、10μmol/L浓度的比卡鲁胺,5、10、20、50 ng/mL浓度的重组人瘦素拮抗剂及二者联合应用(浓度分别为5μmol/L、20 ng/mL)干预24 h。采用MTT法检测细胞增殖抑制率,流式细胞仪检测细胞凋亡率。结果各浓度比卡鲁胺、重组人瘦素拮抗剂及二者联合应用均能显著抑制DU-145细胞增殖,诱导其凋亡;二者联合应用的细胞增殖抑制率、细胞凋亡率均明显高于相同浓度的比卡鲁胺和重组人瘦素拮抗剂单用;P均<0.05。结论比卡鲁胺和重组人瘦素拮抗剂均可抑制DU-145细胞增殖,诱导其凋亡;二者联合应用有协同作用。

益肾通癃汤对人前列腺癌DU-145细胞上皮-间质转化及Ras/ERK信号通路的影响

目的:观察益肾通癃汤对人前列腺癌DU-145细胞上皮-间质转化(EMT)及Ras/ERK信号通路的影响并探讨其作用机制。方法:将人前列腺癌DU-145细胞分为空白血浆组,益肾通癃汤含药血浆高、中、低剂量组(以下简称中药高、中、低剂量组)。运用CCK-8法观察各组DU-145细胞增殖情况,Annexin V&PI双染色法进行细胞凋亡检测,PI法进行细胞周期检测,Transwell小室及划痕实验法检测各组DU-145细胞侵袭能力及迁移情况,Western印迹检测益肾通癃汤干预后各组DU-145细胞EMT及Ras/ERK信号通路相关蛋白的表达变化,RT-PCR检测DU-145细胞EMT及Ras/ERK信号通路相关蛋白的基因表达情况。结果:与空白血浆组对比,中药高、中、低剂量组均可显著抑制DU-145细胞增殖,降低其贴壁生长能力并呈剂量依赖性(P<0.05,P<0.01);中药高、中、低剂量组可显著促进人前列腺癌DU-145细胞凋亡并呈剂量依赖性(P<0.01);中药高、中、低剂量组可显著调控DU-145细胞周期并呈剂量依赖性(P<0.05,P<0.01);中药高、中、低剂量组可显著降低人前列腺癌DU-145细胞体外侵袭、迁移能力并呈剂量依赖性(P<0.05);Western印迹结果显示,与空白血浆组比较,中药高、中、低剂量组人前列腺癌DU-145细胞中N-钙黏蛋白(N-cadherin)、锌指转录因子(Snail)、Ras、p-ERK1/2、ERK1/2、基质金属蛋白酶(MMP-9)等蛋白表达均存在一定程度的下调,而E-钙黏蛋白(E-cadherin)表达上调并存在显著差异(P<0.05,P<0.01);RT-PCR结果显示,中药高、中、低剂量人前列腺癌DU-145细胞N-cadherin mRNA、Ras、ERK1表达下调,而E-cadherin mRNA表达上调并存在显著差异(P<0.05,P<0.01)。结论:益肾通癃汤能够有效抑制人前列腺癌DU-145细胞的增殖并促进其凋亡,调控细胞周期,抑制其侵袭及迁移能力及EMT进程,益肾通癃汤治疗前列腺癌的作用机制可能是通过抑制前列腺癌细胞EMT进程及Ras/ERK信号通路表达有关。

Effects of miR-200c on the migration and invasion abilities of human prostate cancer Du145 cells and the corresponding mechanism

microRNAs （miRNAs） have played a key role in human tumorigenesis, tumor progression, and metastasis. On the one hand, miRNAs are aberrantly expressed in many types of human cancer; on the other hand, miRNAs can function as tumor suppressors or oncogenes that target many cancer-related genes. This study aimed to investigate the effects of miRNA-200c （miR-200c） on the biological behavior and mechanism of proliferation, migration, and invasion in the prostate cancer cell line Du145. In this study, Du145 cells were transfected with miR-200c mimics or negative control miR-NC by using an X-tremeGENE siRNA transfection reagent. The relative expression of miR-200c was measured by RT-PCR. The proliferation, migration, and invasion abilities of Du145 cells were detected by CCK8 assays, migration assays and invasion assays, respectively. The expressions of ZEB1, E-cadherin, and vimentin were observed by western blot. Results showed that DU145 cells exhibited a high expression of miR-200e compared with immortalized normal prostate epithelial cell RWPE-1. Du145 cells were then transfected with miR-200c mimics and displayed lower abilities of proliferation, migration, and invasion than those transfected with the negative control. The protein levels of ZEB1 and vimentin were expressed at a low extent in Du145 cells, which were transfected with miR-200c mimics; by contrast, E-cadherin was highly expressed. Hence, miR-200c could significantly inhibit the proliferation of the prostate cancer cell line Du145; likewise, miR- 200c could inhibit migration and invasion by epithelial-mesenchymal transition.

Effects of bortezomib in sensitizing human prostate ：ancer cell lines to NK-mediated cytotoxicity

The proteasome inhibitor, bortezomib, has been demonstrated to sensitize tumor cells to tumor necrosis factor-related apoptosis-inducing ligand （TRAIL）-mediated apoptosis. Natural killer （NK） cells represent potent antitumor effector cells. They also express TRAIL. Therefore, we investigated whether bortezomib could sensitize tumor cells to NK cell-mediated killing, and have the same effect in human prostate cancer cell lines （LNCaP and DU145）. We found that bortezomib strongly inhibits proliferation in both cell lines. Furthermore, compared with LNCaP cells, DU145 cells are more sensitive to bortezomib-induced apoptosis. However, bortezomib is unable to sensitize these two cell lines to NK cell-mediated killing in short-term assays. In long-term assays, we found that killing mediated by activated NK cells following bortezomib treatment leads to greater antitumor effects than either treatment alone. In addition, treatment with bortezomib causes these cells to upregulate apoptosis-related mRNA as well as death receptors and downregulate the major histocompatibility class （MHC）-I molecule on the cell surface of DU145 cells. In contrast, LNCaP cells are not sensitized by this treatment. Death receptors and the MHC-I molecule did not change in this cell line. These data suggest that bortezomib can be used to sensitize prostate cancer cells to NK cell-mediated killing and improve current cancer therapies. This theral）eutic stratelzv may be more effective in I）atients with androeen-insensitive orostate cancer.