Over-expression of hypoxia-inducible factor 1 alpha increases angiogenesis of LNCaP cells

Objective:To evaluate the effect of HIF-1 α over-expression on angiogenesis in human prostate cancer cells. Methods:LNCaP cells(a human prostate cancer cell line) were transfected with the recombinant plasmid pcDNA3.1(-)-HIF-1α with Lipofectamine 2000 system. The positive clones were selected by G418 being further confirmed by Western blot and immunofluorescence. The expression levels of VEGF, iNOS and Ang- Ⅱ were determined. Results:The expression of HIF-1α in the LNCaP/HIF1α cells was significantly increased in transfected cells, which induced the up-regulation of VEGF, iNOS, whereas Ang- Ⅱ expression remained un- changed. Conclusion :Over-expression of HIF-1α can induce angiogenesis proteins and may improve the angiogenesis potency of prostate cancer.     

Inhibitory Effect of Matrine on the Expression of PSA and AR in Prostate Cancer Cell line LNCaP

In order to investigate the inhibitory effect of matrine on the expression of prostate specific antigen （PSA） and androgen receptor （AR） in prostate cancer cell line LNCaP in vitro, LNCaP cells were treated with matrine at different concentrations （0.5, 1.0, 1.5, 2.0 g/L） for 12-36 h. The growth activities of cancer cells were determined by MTT colorimetric assay. The AR level was measured by Western blotting. The expression of PSA was detected by using AXSYM system-chemical luciferase methods. The results showed that matrine could effectively inhibit the growth of androgen-dependent prostate cancer cell line LNCaP in vitro in a time-and dose-dependent manner （P〈0.05）. It could obviously decrease the level of AR （P〈0.01） and inhibit the expression of PSA in a dose-dependent manner （P〈0.05） in LNCaP cells. It was concluded that matrine could significantly suppress the growth of LNCaP cells and inhibit the expression of PSA and AR of prostate cancer cells.     

Hypoxia-Inducible Factor-lalpha Suppressing Apoptosis and Increasing Tolerance of Lung Cancer Cells to Chemotherapy

In order to construct plasmid of hypoxia-inducible factor-lalpha （HIF-1α）, and transfect into human lung cancer cells A549, the change in sensitivity of lung cancer cells A549 to chemotherapy was observed. HIF-1α mRNA structure region was amplified by RT-PCR and inserted into plasmid pcDNA3. The expression plasmid pcDNA3/HIF-1α was transfected into A549 with LipofectAMINE^TM2000. The expression of HIF-1α protein was detected by Western blot. After A549 cells were transfected with HIF-1α prior to addition of 5-Fu, the growth activity was measured by growth curve, apoptosis was detected by flow cytometry at 48 h, and the levels of caspase3 and MDR-1 were determined by Western blot. The results showed that the constructed expression plasmid was analyzed with restriction enzymes and gel electrophoresis. Two DNA lanes at 2.55 kb and 5.4 kb respectively were found, which were consistent with that expected. The growth rate in 5-Fu group was significantly inhibited, and the apoptosis index and caspase3 activity were increased significantly as compared with control group. After HIF-1α being transfected into A549, the activity of MDR-1 was increased and the effect of 5-Fu was weakened. In conclusion, HIF-1α can promote chemoresistance by increasing the activation of MDR1 and suppressing apoptosis during lung cancer cells A549 in- duced with 5-Fu.     

Construction of Smac gene-carrying and human uroplakin Ib promoter-Regulated Genetic Vector and its Expression

Objective： To construct an eukaryotic expression vector that contains Smac gene, which is regulated by human Uroplakin Ib （UpIb） promoter. Methods： For the directionality of Smac expression in the transitional cell carcinoma of bladder, internal CMV and T7 promoter sequences in eukaryotic expression vector pcDNA3.1-Smac were replaced with UpIb promoter to construct a new plasmid. The plasmid DNA was identified by gel electrophoresis after being double digested at respective sites, and then the sequence was analyzed. The expression of Smac mRNA and protein in BIU87 cell line were detected after the transfection by using the newly constructed vector. Results： The Smac gene-carrying and UpIb promoter-regulated eukaryotic expression vector pcDNA3-UpIb-promoter-Smac was successfully constructed. The expression of Smac mRNA was approximately increased by 2.1 times and the expression of Smac protein was increased in about 71% BIU87 cells. Conclusion： The new vector can be effectively expressed in bladder cancer cells and be of great significance for bladder cancer-targeted gene therapy.     

Effect of hypoxia-inducible factor-1α on proliferation and invasion of prostate cancer PC-3 cell in hypoxic situation

<正>Objective We transfected recombinant expression plasmid of pcDNA3. 1-HIF-1α into prostate cancer cells, to research effect of HIF-1α on proliferation of prostate cancer cell PC-3. Methods We selected a stable expression cell line with G418 we selected by transfection of     

Expression and biological function of N-myc down-regulated gene 1 in human cervical cancer

The expression of N-myc down-regulated gene 1 (NDRG1) has previously been reported to be involved in the proliferation,differentiation,invasion and metastasis of cancer cells,but its role in cervical cancer is still unclear.This study aimed to investigate the expression of NDRG1gene in human cervical cancer and its effect on aggressive tumor behaviors.The NDRG1 expression in cervical tissues and cells was detected by RT-PCR.Specific expression plasmid pEGFP-N1-NDRG1-GFP was used to enhance the expression of NDRG1 in human cervical cancer cell lines.The mRNA and protein level of NDRG1 was assessed by RT-PCR and Western blotting,respectively.Its effects on cell proliferation,migration,invasion,cell cycle and apoptosis were detected by MTT,transwell migration assay and flow cytometry (FCM),respectively.The results showed that the expression of NDRG1 in cervical cancer tissues and cells was significantly lower than in normal cervical tissues (P<0.001).After transfection with pEGFP-N1-NDRG1-GFP,the mRNA and protein expression of NDRG1 was up-regulated in Siha cells,which suppressed cell proliferation (P<0.001),induced cell cycle arrest (P<0.05),reduced invasion and migration of Siha cells (P<0.05),but caused no cell apoptosis.Moreover,vascular endothelial growth factor (VEGF),a tumor-induced angiogenesis factor,was markedly reduced and E-cadherin,a cell adhesion molecule,was increased in the cells transfected with pEGFP-N1-NDRG1-GFP.It was concluded that up-regulated NDRG1 may play a role in the suppression of malignant cell growth,invasion and metastasis of human cervical cancer.     

Implication of expression of Nanog in prostate cancer cells and their stem cells

Recent studies suggested that the prostate cancer may arise from prostate cancer stem cells that share some same characteristics with normal stem cells. The purpose of this study was to detect the differences of Nanog expression between PC3 prostate cancer cell line and its tumor stem cells, and the relationship was preliminarily examined between Nanog and prostate cancer and its tumor stem cells. By using magnetic active cell sorting (MACS), we isolated a population of CD44+/CD133+ prostate cancer cells that display stem cell characteristics from PC3 cell line. Immu-nohistochemistry revealed positive expressions of CD44, CD133 and α2β1-integin in the isolated cells. CCK-8 analysis showed that isolated cells had a strong proliferative ability. The formation of the cell spheres in serum-free medium and holoclones in serum-supplied medium showed that the cells were capable of self-renewing, indicating that the isolated cells were a population of cancer stem-like cells derived from PC3 cell line. Western blotting exhibited that the isolated cells had higher experession of Nanog, an embryonic stem marker, as compared with PC3 cells. Our study showed that Nanog might be helpful in sustaining the self-renewal and the undifferentiation of prostate cancer stem cells, and may serve as a marker for prostate cancer stem cells for isolation and identification.     

Inhibitory Activity of Nuclear Factor-κB Potentiates Cisplatin-induced Apoptosis in A549 Cells

Whether inhibiting the activity of nuclear factor(NF)-κB potentiates cisplatin-induced apoptosis in non-small cell lung cell line A549 cells was investigated.The recombinant plasmid pcDNA3.1( )/IκBα expressing IκBα was constructed.The in vitro cultured A549 cells were transfected with pcDNA3.1( )/IκBα alone,or pcDNA3.1( )/IκBα combined with cisplatin.The mito-chondrial membrane potential(?ψm) was determined by rhodamine 123,the activity of caspase-3 was tested by colorimetric assay,and cell apoptosis was detected by flow cytometry with the annexin Ⅴ/propidium iodide assay.The results showed that the activity of NF-κΒ in A549 cells was inhibited by transfecting pcDNA3.1( )/IκΒα.Transfection of pcDNA3.1( )/IκΒα alone did not promote apoptosis.Treatment of cisplatin alone had a little effect on cell apoptosis.Transfection of pcDNA3.1( )/IκΒα combined with cisplatin treatment significantly induced apoptosis of A549 cells.It was concluded that inhibiting the activity of NF-κB potentiated cisplatin-induced apoptosis of A549 cells.     

缺氧诱导因子1α过表达对人前列腺癌细胞体外侵袭能力的影响

目的观察转染缺氧诱导因子1α(HIF-1α)能否增强人前列腺癌细胞的体外侵袭能力,并探讨其分子机制。方法用脂质体Lipofectamine2000包装重组真核表达载体pCDNA3．1(-)／HIF1α后转染人前列腺癌细胞LNCaP,600μg／ml G418筛选稳定表达HIF-1α的抗性克隆。免疫荧光及Western印迹法鉴定HIF-1α过表达,Western印迹法检测侵袭相关蛋白E-钙黏素、波形纤维蛋白(vimentin)、基质金属蛋白酶-2(MMP-2)、组织蛋白酶D(cathepsin D)及尿激酶型纤溶酶原激活因子受体(uPAR)的表达,Transwell验证细胞侵袭能力。结果与未转染细胞LNCaP相比,转染细胞LNCaP／HIF1α中出现明显的HIF-1α蛋白条带,并激发出较强荧光,E-钙黏素表达缺失,而vimentin、MMP-2、cathepsin D及uPAR表达增加。Transwell试验进一步证实,LNCaP／HIF1α穿透Matrisel滤膜的细胞数比LNCaP细胞显著增多(4．6±0．4 vs 3．2±0．3,P<0．05)。结论HIF-1α过表达能够诱导人前列腺癌LNCaP细胞的侵袭相关蛋白表达增多,进而显著增强其体外侵袭能力。     

人同源盒基因NKX3.1cDNA真核表达载体的构建及表达

目的：构建人同源盒基因NKX3.1 cDNA真核表达载体，研究其在前列腺癌细胞PC 3、LNCaP中的表达情况。方法：以人前列腺癌细胞LNCaP细胞中的总RNA为模板,RT PCR扩增NKX3.1基因全长编码片段，T/A克隆至pCR2.1载体中。经酶切、测序鉴定后,将NKX3.1cDNA重组到真核表达载体pcDNA3.1（+）中。将pcDNA3.1 NKX3.1表达载体瞬时转染前列腺癌细胞PC 3和LNCaP 细胞,RT PCR和Western blot法检测NKX3.1cDNA在转录水平和蛋白水平的表达。结果：人同源盒基因NKX3.1 cDNA真核表达载体pcDNA3.1 NKX3.1经酶切及测序鉴定正确。 pcDNA3.1 NKX3.1转染PC 3和LNCaP细胞后，经RT PCR和Western blot证明在mRNA和蛋白水平均能有效表达NKX3.1。结论：成功构建了真核表达载体pcDNA3.1 NKX3.1, 转染前列腺癌细胞PC 3和LNCaP后能有效表达。     

HP1α（CBX5）对前列腺癌细胞迁移、侵袭和增殖影响的研究

目的:探讨HP1α在前列腺癌细胞LNCaP和PC3中的表达情况,并研究HP1α的表达对LNCaP和PC3的影响。方法:采用qPCR及Western 印迹检测HP1α的表达情况,通过Transwell检测细胞的迁移和 侵袭能力,CCK-8和集落形成检测细胞的增殖能力。结果:HP1α在前列腺癌细胞C4-2和LNCaP中表达水平最高,PC3和DU145次之,良性前列腺增生的最低（P <0.05）;Transwell显示,与si-NC组相比, si-HP1α组前列腺癌细胞LNCaP和PC3的迁移和侵袭能力均降低（P <0.05）;CCK-8和集落形成实验显示敲低HP1α后,前列腺癌细胞LNCaP和PC3的增殖能力下降（P <0.05）;Western 印迹发现EMT分子标 志物E-cadherin的表达增加,而N-cadherin、Vimentin等的表达均降低（均P <0.05）。结论:HP1α在前列腺癌细胞LNCaP、C4-2、PC3和DU145中高表达,而降低其表达可以抑制前列腺癌细胞LNCaP和PC3 的迁移、侵袭、增殖以及上皮-间充质转化（EMT）能力。     

缺氧微环境下缺氧诱导因子-1α对前列腺癌细胞上皮间质转化的影响

目的：探讨缺氧诱导因子-1α在缺氧的条件下对前列腺癌细胞发生上皮间质转化的影响。方法在缺氧的环境中培养前列腺癌细胞 PC3,并应用分子生物学的方法检测其是否是发生上皮间质转化的关键转录因子。结果缺氧微环境可以诱导前列腺癌细胞 PC3发生上皮间质转化,缺氧诱导因子-1α起关键的调节作用,并且可以增强前列腺癌细胞的侵袭能力。缺氧条件下抑制缺氧诱导因子-1α的表达可以阻止前列腺癌细胞发生上皮间质转化。结论缺氧微环境通过缺氧诱导因子-1α诱导前列腺癌细胞 PC3发生上皮间质转化。     

FGF8b调控前列腺癌细胞上皮间质转化的分子机制

目的:探讨成纤维细胞生长因子8b(fibroblast growth factor 8b,FGF8b)促进前列腺癌DU145细胞上皮间质转化的分子机制。方法:先选取3组细胞,分别为空白对照组(DU145细胞)、阴性对照组[(DU145细胞转染空白质粒(简称pcDNA3.1/DU145)]和实验组[DU145细胞转染FGF8b(简称FGF8b/DU145)]。采用Western印迹检测细胞外调节蛋白激酶(extracellular regulated protein kinases,ERK)通路活性,然后将FGF8b/DU145细胞及DU145细胞在PD98059(ERK激酶抑制剂)作用下分为4组:A组为2%胎牛血清(FBS)处理的FGF8b/DU145细胞;B组为2%FBS+PD98059(50μmol/L)处理的FGF8b/DU145细胞;C组为2%FBS处理的DU145细胞;D组为2%FBS+PD98059(50μmol/L)处理的DU145细胞,培养观察细胞形态学的变化,最后Western印迹和Transwell小室检测各组细胞上皮-间质转化(epithelial-mesenchymal transition,EMT)相关标志物的变化以及细胞的迁移能力改变。结果:实验组ERK1/2活性明显高于空白对照组和阴性对照组。给予PD98059后,B组与未给予PD98059组的A组相比,上皮细胞标志物上皮钙黏素蛋白表达量明显上调(P<0.05);间质标志物波形蛋白表达量明显下调(P<0.05)。细胞迁移试验结果提示:在给予PD98059后,B组FGF8b/DU145细胞的迁移能力与A组相比明显减弱。结论:FGF8b调控前列腺癌细胞DU145发生上皮-间质转化,可能由ERK激酶通路介导,MAPK激酶1作为该信号通路的关键因子之一,可能是干预前列腺侵袭转移的有效靶点。     

MTBP调控前列腺癌细胞的迁移和侵袭

目的研究鼠双微体2 癌基因结合蛋白（MTBP）对人前列腺癌细胞迁移及侵袭能力的影响及其作用机制。方法用 Western blot检测MTBP在22RV1、DU145及Lncap三种不同前列腺癌细胞中的表达水平。采用siRNA及MTBP质粒分别转染 细胞,转染48 h后,用Western blot检测MTBP蛋白的表达量,划痕实验检测细胞的平行迁移能力,Transwell实验检测细胞的垂 直迁移及侵袭能力。用Western blot 检测细胞上皮间质转化（EMT）标志分子E-cadherin蛋白表达量的变化。结果在前列腺癌 细胞中,MTBP在转移性前列腺癌细胞DU145中表达最高,Lncap细胞次之,局限性前列腺癌细胞22RV1中最低,MTBP的表达 水平与前列腺癌细胞的转移侵袭能力呈正相关。siRNA干扰及MTBP质粒转染细胞分别能显著降低或提高前列腺癌细胞中 MTBP的蛋白表达水平。划痕实验结果显示抑制MTBP的表达后,前列腺癌细胞的迁移能力降低,而MTBP过表达能显著促进 前列腺癌细胞的迁移（P<0.01）。Transwell实验发现抑制MTBP的表达可降低前列腺癌细胞的迁移侵袭能力,而MTBP过表达 后,能显著促进前列腺癌细胞的迁移侵袭能力（P<0.01）;Western blot 结果显示抑制MTBP的表达可使前列腺癌细胞的Ecadherin 蛋白表达水平升高,而MTBP过表达的前列腺癌细胞中E-cadherin蛋白表达水平降低。结论MTBP可促进前列腺癌 细胞的迁移和侵袭,其作用机制可能与诱导EMT有关。     

Slug对食管癌细胞Eca-109侵袭能力的影响及其分子机制探讨

目的研究Slug与食管癌侵袭转移间的关系并探讨其分子机制。方法构建正义全长Slug真核表达载体pcDNA3.1-Slug并转染食管癌细胞系Eca-109;光镜下观察转染前后细胞形态的变化,免疫细胞化学、Westernblot分别检测细胞中上皮标志物E-钙粘素(E-cadherin)与间质标志物波形蛋白(Vimentin)的表达变化,Transwell小室法检测细胞侵袭能力的变化。结果转染pcDNA3.1-Slug真核表达载体后,Eca-109细胞形态变得细长;免疫细胞化学和Western blot结果显示E-cadherin表达明显下调,Vimentin表达则上调;Transwell小室显示转染pcDNA3.1-Slug载体的Eca-109细胞穿透matrigel胶的细胞数明显增多。结论转录因子Slug能促进食管癌上皮细胞间质化转变(epithelial-mesenchymaltransition,EMT),并提高其侵袭转移能力。     

β-连环蛋白信号通路介导缺氧诱导因子1α诱导人前列腺癌细胞的上皮细胞间质转化

目的 明确β-连环蛋白(catenin)信号通路是否参与缺氧诱导因子(HIF)-1α诱导人前列腺癌细胞发生上皮细胞间质转化态(EMT)转化过程.方法 应用Western印迹法检测HIF-1α、Glut-1和VEGF蛋白表达,确认2种新构建前列腺癌细胞株(LNCaP/HIF1α和PC-3/HIF1α)的稳定性;然后应用Western印迹法检测EMT指标蛋白(E-cadherin、CK18、Vimentin、N-cadherin及Fibronetin)的表达,对5种人前列腺癌细胞株(LNCaP、LNCaP/HIF1α、PC-3、PC-3/HIF1α和IA8)的EMT特性进行鉴定;进一步应用Transwell和MTT技术检测5种细胞株的体外侵袭和增殖潜能;最后,用RT-PCR和Western印迹法检测5种EMT特性不同的细胞株中β-catenin、tGSK-3β和pGSK-3β的表达,总结分析该信号通路活性与细胞EMT特性的关联.结果 (1)LNCaP/HIF1α和PC-3/HIF1α中出现明显的HIF-1α蛋白条带,同时Glut-1和VIEGF表达呈强阳性;(2)Pc-3、LNCaP和Pc-3/HIF1α是EMT阴性细胞,而LNCaP/HIF1α和IA8是EMT阳性细胞;(3)PC-3/HIF1α和LNCaP/HIF1α、IA8体现出了较PC-3和LNCaP更为强大的体外侵袭和增殖潜能;(4)与LNCaP和PC-3相比,PC-3/HIF1α和LNCaP/HIF1α、IA8中tGSK-3β和pGSK-3β的蛋白表达相对减少,但p-GSK3β/t-GSK3β比值相应较高,β-catenin蛋白表达在LNCaP/HIF1α和IA8中相对较高,PC-3/HIF1α却表达较低;基因检测结果与前述蛋白表达规律基本一致,但是与β-catenin蛋自在PC-3/HIF1α中低表达不吻合的是,PC-3/HIF1α中β-catenin mBNA水平与其在LNCaP/HIF1α和IA8中一样呈现出强表达特点.结论 β-catenin信号通路的活性状态与细胞EMT特性及其体外侵袭和增殖潜能有密切关系,该信号通路可能是介导HIF-1α诱导人前列腺癌细胞EMT过程的重要"桥梁".