IGFBP-3在真核细胞中的分泌表达及功能分析

将人胰岛素样生长因子结合蛋白3(IGFBP-3)的cDNA片段亚克隆入pSectagA载体, 构建真核分泌型表达载体pSectag-IGFBP3。采用脂质体转染的方法将真核表达载体转染人肾癌786-O细胞, 转染48 h后用免疫印迹法检测IGFBP-3的表达状况; 同时以Annexin V-EGFP/PI染色, 流式细胞仪检测细胞凋亡率, 观察分泌表达的IGFBP-3对宿主细胞的促凋亡作用。转染48 h后, 经Western blotting检测, 在细胞培养上清中有分泌表达的IGFBP-3蛋白。流式细胞技术检测结果表明, 表达产物可直接作用于宿主细胞, 发挥促肿瘤细胞凋亡的作用。由此表明所构建的重组表达质粒pSectag-IGFBP3能在真核细胞水平正常表达并发挥生物学功能, 为进一步探索IGFBP-3的作用机制奠定了基础。     

人神经生长因子信号肽介导β-内啡肽的分泌表达

目的:构建人神经生长因子信号肽与人β-内啡肽融合基因的真核表达载体,研究人神经生长因子信号肽介导β-内啡肽的分泌表达.方法:取得人基因组后,PCR 法获取人的神经生长因子信号肽部分序列及人β-内啡肽序列;通过 SOE-PCR法将两段 DNA 序列连接,然后插入到真核表达载体内,测序正确后扩增转染级的真核表达载体.表达载体脂质体法转染 NIH3T3细胞,转染后 48-72h 收集细胞及培养上清,RT-PCR 法检测融合基因的转录.RIA 法测定细胞外β-内啡肽的浓度.结果:成功构建全人源的分泌型表达β-内啡肽的真核表达载体,DNA 序列经测序完全符合实验设计;融合基因能够顺利地得到转录并进行表达翻译,在细胞培养上清中可检测到其产物.结论:构建的真核表达载体能够分泌表达人β-内啡肽,提示人神经生长因子信号肽序列能够发挥其介导蛋白产物分泌表达的作用.     

人同源盒基因NKX3.1对前列腺癌细胞的诱导凋亡作用

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 中的表达及对细胞的促凋亡作用.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,将NKX3.1 cDNA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,用RT-PCR和Western印迹检测NKX3.1 cDNA在转录水平和蛋白水平的表达;绘制细胞生长曲线,观察NKX3.1对前列腺癌细胞增殖的抑制作用;用DNA/ladder和流式细胞术检测NKX3.1对前列腺癌细胞凋亡的影响,进一步用RT PCR检测凋亡相关基因caspase3、caspase8、caspase9、Apaf1、survivin和Bcl2表达的变化.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印迹证明能有效表达NKX3.1.生长曲线显示,前列腺癌细胞转染NKX3.1 cDNA后细胞增殖受到抑制;前列腺癌细胞转染NKX3.1 cDNA 48 h后,DNA电泳呈现具有凋亡特征的DNA ladder;流式细胞术检测出现明显凋亡峰;RT-PCR检测凋亡相关基因.结果显示,caspase3、caspase8、caspase9基因表达明显增加,Bcl2基因表达明显减少.本研究成功构建了真核表达载体pcDNA3.1 NKX3.1, 转染PC3和LNCaP细胞后能有效表达,并对细胞具有诱导凋亡作用     

人Bcl2基因真核表达载体的构建及其抗凋亡功能研究

目的:构建带myc标签的Bcl2真核表达载体,获得myc-Bcl2融合蛋白,并对其生物学功能进行初步检测。方法:以本实验室保存的乳腺文库为模板,采用PCR技术扩增Bcl2编码序列,将其插入p CMV-myc载体,Western印迹检测表达情况;将重组质粒与空载体分别转染乳腺癌MCF-7细胞,通过流式细胞仪检测p CMV-myc-Bcl2重组质粒对细胞凋亡的影响。结果:双酶切和测序结果表明p CMV-myc-Bcl2真核表达质粒构建成功;转染293T细胞后myc-Bcl2蛋白成功表达;流式细胞仪检测结果显示,myc-Bcl2明显抑制乳腺癌细胞系的凋亡。结论:构建了带myc标签的人Bcl2真核表达载体,为进一步研究Bcl2在细胞凋亡中的功能奠定了基础。     

骨形成蛋白7基因诱导人肝癌细胞的凋亡

目的 构建表达重组人骨形成蛋白7 （bone morphogenic protein 7, BMP7）基因的重组逆转录病毒,观察其对人肝癌细胞HepG2的凋亡诱导活性,并探讨其作用机制。方法 克隆BMP7基因,以loxP同源重组法构成逆转录病毒载体pLP-LNCX-BMP7（pLLBMP7）,转染包装细胞PT67进行病毒包装并测定病毒滴度;将逆转录病毒感染人成骨细胞,MTT法检测细胞生长变化,琼脂糖凝胶电泳和流式细胞仪检测肿瘤细胞的凋亡;Western blotting检测BMP7,caspase-3和bcl-2蛋白表达。结果 重组逆转录病毒载体pLLBMP7经鉴定连接正确,转染PT67细胞后上清液中可得到病毒,滴度达1×109pfu;MTT检测见pLLBMP7病毒组48和72h细胞抑制率高于对照组（35.1% vs. 5.3%,68.5% vs.18.3%,均p<0.05）,48h可见BMP7蛋白高表达。琼脂糖凝胶电泳出现典型梯形条带;流式细胞仪检测出现凋亡峰,于转染48h后达最高峰,其凋亡百分率高达14.42%;BMP7蛋白高表达时caspase-3蛋白的表达亦有显著升高,但bcl-2蛋白未见表达差异。结论 构建了BMP7逆转录病毒,在体外能够有效地诱导人肝癌细胞HepG2的凋亡,其可能是通过激活caspase-3而发生作用。     

重组抗HER2 ScFv/tBid 基因的表达对SGC7901胃癌细胞的促凋亡作用

目的：构建重组抗HER2 ScFv/tBid载体并观察其对胃癌SGC7901细胞的促凋亡作用。 方法： 将重组抗HER2 ScFv/tBid基因克隆入真核表达载体pCMV中,转染SGC7901细胞,用RT-PCR方法检测目的基因在mRNA水平的表达,间接免疫荧光法检测目的蛋白表达和细胞形态学变化,通过细胞计数检测转染目的基因后对细胞生长的影响,通过检测细胞周期来观察其促凋亡作用。 结果：转染SGC7901细胞后,检测出目的蛋白的表达。细胞计数发现细胞的增殖被明显抑制。细胞周期分析有明显的凋亡峰出现,说明重组抗HER2 ScFv/tBid表达后有促凋亡作用。 结论： 重组抗HER2 ScFv/tBid基因可以在转染的SGC7901细胞中表达,并且可抑制转染细胞的生长,诱导细胞发生凋亡。     

B19病毒XA株VP1独特区蛋白对Hela细胞凋亡的影响

目的:构建B19病毒XA株VPlu基因的真核表达载体和稳定转染细胞系,探讨B19病毒XA株VPl独特区蛋白对Hela细胞凋亡的影响。方法:采用本课题组前期构建的真核表达载体plRES2-EGFP-Vplu及plRES2-EGFP对照质粒,将其稳定转染至Hela细胞,通过流式细胞术检测EGFP阳性细胞的比例以确定稳定转染的细胞系是否成功构建;提取稳定转染的Hela细胞的总蛋白,通过Western blot检测细胞内凋亡相关基因Caspase3的表达;转染plRES2-EGFP-Vplu及plRES2-EGFP的Hela细胞经过Annexin V和PI的染色后,通过流式细胞术检测其凋亡率。结果:本实验成功构建了plRES2-EGFP-VPlu稳定转染的Hela细胞系,plRES2-EGFP-Vplu稳定转染的Hela细胞中Caspase3的表达较转染对照质粒的Hela细胞明显增加,细胞凋亡率亦显著升高,差异均具有统计学意义(P0.05)。结论:B19病毒XA株VP1独特区蛋白能够显著促进Hela细胞的凋亡。     

人星状病毒非结构蛋白基因nsP1a/1真核表达载体构建及其

目的 将人星状病毒非结构蛋白nsP1 a./1基因连接到真核表达载体上,转染人胚肾上皮细胞48 h后检测其表达.方法 设计特异性引物PCR扩增人星状病毒非结构蛋白nsP1 a/1片段,分别插入真核表达载体pcDNA3.1(+)和pEGFP-N2载体,构建重组表达质粒pcDNA3.1(+)-nsP1a/1-His和pEGFP-N2-nsP1a/1.在转染试剂PEI的介导下将重组表达质粒分别转染293T细胞,转染48 h后分别在荧光显微镜下观察EGFP的表达以及通过Western blot检测nsP1a/1基因的表达.结果 重组表达质粒pcDNA3.1(+)-nsP1a/1-His和pEGFP-N2-nsP1a/1构建成功;转染pEGFP-N2-nsP1a/1后48 h能够在荧光显微镜蓝色激发光下观察到较强的黄绿色荧光;转染pcDNA3.1(+)-nsP1a/1-His后48 h收集细胞进行Western blot检测,能够检测到nsP1a/1-His融合报告基因的表达.结论 成功构建了人星状病毒非结构蛋白nsP1a/1基因真核表达质粒,并在人胚肾上皮细胞293T细胞获得表达,为进一步深入研究nsP1a/1在人星状病毒抵御宿主细胞抗病毒天然免疫中是否发挥作用奠定了基础.     

HCV核心蛋白诱导Cos—7细胞凋亡

将丙型肝炎病毒(HCV)核心蛋白(Core)基因的全长序列插入到真核表达载体pCDNA3 CMV启动子下游,构建真核表达载体pCDNA3—Core,用脂质体LipoVec^TM转染Cos—7细胞系进行瞬时表达;DNA转染24h后用免疫斑点试验检测在细胞中表达的Core蛋白;转染72h后用Hoechst染色和DNA Ladder检测Cos—7细胞的凋亡情况;荧光染色观察到了细胞凋亡核碎裂,琼脂糖凝胶电泳也呈现出180—200bp整数倍的梯形带,呈现典型的细胞凋亡特征。这些结果表明HCV Core蛋白的表达能引起Cos—7细胞凋亡,Core蛋白的这种功能可能在HCV的持续感染过程中起着一定的作用。     

HCV核心蛋白诱导Cos-7细胞凋亡

将丙型肝炎病毒(HCV)核心蛋白(Core)基因的全长序列插入到真核表达载体pCDNA3 CMV启动子下游,构建真核表达载体pCDNA3-Core,用脂质体LipoVecTM转染Cos-7细胞系进行瞬时表达;DNA转染24h后用免疫斑点试验检测在细胞中表达的Core蛋白;转染72h后用Hoechst染色和DNA Ladder检测Cos-7细胞的凋亡情况;荧光染色观察到了细胞凋亡核碎裂,琼脂糖凝胶电泳也呈现出180-200bp整数倍的梯形带,呈现典型的细胞凋亡特征.这些结果表明HCV Core蛋白的表达能引起Cos-7细胞凋亡,Core蛋白的这种功能可能在HCV的持续感染过程中起着一定的作用.     

Insulin-like factor binding protein-3 promotes the G1 cell cycle arrest in several cancer cell lines

Insulin-like growth factor binding protein-3 (IGFBP-3) is a multi-functional protein known to induce apoptosis of various cancer cells in an insulin-like growth factor (IGF)-dependent and IGF-independent manner. In our previous study, we found that IGFBP-3 induced apoptosis through the activation of caspases in 786-O cells. In this study, we further examined that whether IGFBP-3 induced apoptosis through the induction of cell cycle arrest in 786-O, A549 and MCF-7 cells. Our results showed that overexpressed IGFBP-3 resulted in typical apoptotic ultrastructures in A549 cells under transmission electron microscope. The result of flow cytometry analysis indicated that IGFBP-3 arrested the cell cycle at G1-S phase in 786-O, A549 and MCF-7 cells. In A549 cells, quantitative real-time PCR and Western blot analysis showed a significant change in the expression of cell cycle-regulated proteins—a decrease in cyclin E1 expression, an increase in p21 expression. These results indicate a possible mechanism for G1 cell cycle arrest by IGFBP-3. Taken together, cyclin E1 and p21 may play important roles in the IGFBP-3-inducing G1 cell cycle arrest and apoptosis in several human cancer cells.     

Ectopic expression of von Hippel-Lindau tumor suppressor induces apoptosis in 786-O renal cell carcinoma cells and regresses tumor growth of 786-O cells in nude mouse

The von Hippel-Lindau (VHL) is a known tumor suppressor that binds to alpha-subunits of hypoxia-inducible factors and induces ubiquitin-mediated degradation of the protein in an oxygen-dependent manner. VHL is also involved in the regulation of tumor angiogenesis, glycolysis, cell cycle regulation, and apoptosis. In the present study, we showed that ectopic expression of VHL induces apoptosis in renal cell carcinoma 786-O cells which contain only the mutant VHL, evidenced by TUNEL assay and DAPI staining. Furthermore, biochemical studies indicated that expression of VHL in 786-O cells results in both PARP and CPP32 cleavage, suggesting that VHL-induced apoptosis in 786-O cells is caspase dependent. Moreover, we also observed that apoptosis induced by ectopic VHL expression was associated with up-regulation of p27 as well as Bax, implicating the roles of these two proteins in VHL-induced apoptosis. The up-regulation of p27 and Bax by VHL was specific since we did not detect any changes in the level of other apoptotic factors including Fas and Bcl2 by the expression of VHL. We next examined the effect of VHL expression on the tumor growth of 786-O renal cell carcinoma cells in nude mouse. The results showed that injection of Ad.VHL adenovirus regresses the tumor growth of 786-O cells in nude mouse. The analysis by TUNEL assay as well as DAPI staining of 786-O tumors injected with Ad.VHL showed clear evidence of apoptosis. These results suggest that ectopic VHL expression induces apoptotic response in 786-O VHL mutant cells both in vitro and in vivo.     

Timosaponin AIII inhibits metastasis of renal carcinoma cells through suppressing cathepsin C expression by AKT/miR-129-5p axis

Timosaponin AIII (TSAIII) is a steroidal saponin that exerts anticancer activity on various cancer cells. In this study, we explore the effects of TSAIII on renal cell carcinoma (RCC) cells. Our findings show that TSAIII treatment (<8 μM) insignificantly influenced cell viability and cell cycle distribution of human RCC cell lines 786-O, A-498, and ACHN. Further observations revealed that TSAIII inhibited migration and invasion of 786-O and A-498 cells, as well as significantly decreased the production and expression of cathepsin C (CTSC) in both the cell types. Kinase cascade analysis exhibited that PI3K/AKT activation was inhibited, but PTEN expression was increased, in response to TSAIII treatments. Combining TSAIII and PI3K inhibitors, LY294002 synergically reduced the migration and invasion of 786-O and A-498 cells, as well as decreased the CTSC expression in both the cell types. We also observed that miR-129-5p bound to CTSC gene and suppressed the expression of CTSC and demonstrated that the miR-129-5p expression was synergically enhanced by TSAIII and LY294002. In addition, pretreatment with antago-miR-129-5p significantly restored the CTSC expression and the migration and invasion of TSAIII-treated 786-O cells. In conclusion, our findings reveal that TSAIII inhibits the metastatic properties of RCC cells, contributing to the inhibition of PI3K/AKT and the increase of miR-129-5p and the subsequent downregulation of CTSC. This suggests that TSAIII has significant antimetastatic activity against RCC cells and may be beneficial to RCC treatments.     

β-Ionone represses renal cell carcinoma progression through activating LKB1/AMPK-triggered autophagy

β-Ionone, the end ring analog of β-carotenoids, has been proven to have an antitumor effect in a variety of cancers. In this study, we investigated the impact of β-ionone on renal cell carcinoma (RCC) cell lines (786-O and ACHN) using colony formation assays, flow cytometry analysis, and western blot analysis. We found that β-ionone effectively inhibited the proliferation of RCC cells in vitro, which was also confirmed in a xenograft model. Moreover, we found that β-ionone could induce autophagy, as indicated by LC3 puncta in 786-O and ACHN cell lines and the expression of LC3 in β-ionone-treated RCC cells. To further explore the underlying mechanism, we assessed liver kinase B1/AMP-activated protein kinase (LKB1/AMPK) signaling pathway activity, and the results showed that β-ionone inhibited the proliferation of RCC cells by inducing autophagy via the LKB1/AMPK signaling pathway. In summary, our findings provide a new therapeutic strategy of β-ionone-induced autophagy in RCC.     

Anti-tumor effects of fusion vaccine prepared by renal cell carcinoma 786-O cell line and peripheral blood dendritic cells of healthy volunteers in vitro and in human immune reconstituted SCID mice

Dendritic cells (DC), as professional antigen presenting cells, play the central role in the process of body initiating the anti-tumor immunity, and the study on DC anti-tumor vaccine has become heated in recent years. In this study, we used polyethylene glycol (PEG) to induce renal cell carcinoma (RCC) 786-O cell line fused with peripheral blood DC of healthy volunteers, and discuss the biological characteristics of fusion vaccine and its anti-tumor effects in vitro and in human immune reconstituted SCID mice model of RCC. The study found that PEG could effectively induce cell fusion, and the expressions of CD86 and HLA-DR in fusion vaccine group were significantly up-regulated compared with the DC control group; the secretion of IL-12 was much higher and longer than that of the control; the functions of dendritic cell-tumor fusion vaccine to stimulate the proliferation of allogenic T lymphocytes and to kill RCC786-O cells in vitro were significantly higher than those of the control group, and after the killing, apoptosis body was observed in the target cells; after the injection of fusion vaccine into human immune reconstituted SCID mice model of RCC786-O via vena caudalis, the volume of mice tumor was reduced significantly, proliferation index of tumor cells decreased obviously compared with that of the control group, and more hemorrhage and putrescence focuses presented, accompanying large quantity of lymphocytes soakage. The results of this experimental study shows that fusion vaccine of RCC786-O cell line and DC can significantly stimulate the proliferation of allogenic T cells and specifically inhibit and kill RCC cells in vitro and in vivo, which makes the DC-RCC786-O fusion vaccine a possible new way of effective RCC immunotherapy.     

Hyperthermia Induces Apoptosis of 786-O Cells through Suppressing Ku80 Expression

Hyperthermia as an anticancer method has been paid increasing attention in recent years. Several studies have shown that hyperthermia can kill tumor cells by inducing apoptosis. However, the underlying molecular mechanisms of hyperthermia-induced apoptosis are largely unknown. To investigate the effects and molecular mechanism of hyperthermia on the apoptosis in renal carcinoma 786-O cells, we firstly examined apoptosis and Ku expression in 786-O cell line treated with heat exposure (42°C for 0-4 h). The results showed that hyperthermia induced apoptosis of 786-O cells, and suppressed significantly Ku80 expression, but not Ku70 expression. Next, we knock-down Ku80 in 786-O cells, generating stable cell line 786-O-shKu80, and detected apoptosis, cell survival and cell cycle distribution. Our data showed higher apoptotic rate and lower surviving fraction in the stable cell line 786-O-shKu80 compared with those in control cells, exposed to the same heat stress (42°C for 0-4 h). Moreover, the results also showed suppression of Ku80 led to G2/M phase arrest in the stable cell line 786-O-shKu80 following heat treatment. Together, these findings indicate that Ku80 may play an important role in hyperthermia-induced apoptosis and heat-sensitivity of renal carcinoma cells through influencing the cell cycle distribution.     

LINC00961 restrains cancer progression via modulating epithelial–mesenchymal transition in renal cell carcinoma

Recently, long noncoding RNA have been identified as new gene regulators and prognostic biomarkers in various cancers, including renal cell carcinoma (RCC). The expression and biological roles of LINC00961 have been reported in many human cancers. However, up to date, no study of LINC00961 has been shown in RCC. Currently, we aimed to investigate the function of LINC00961 in RCC progression. Interestingly, we observed that LINC00961 could act as a novel biomarker in predicting the diagnosis of RCC. Then, we found that LINC00961 was greatly downregulated in RCC cell lines (Caki-1, Caki-2, 786-O, A498, and ACHN cells) compared with normal renal cell lines (HK-2 cells). Then, 786-O cells and ACHN cells were infected with LV-LINC00961. As displayed in our current study, LINC00961 overexpression could obviously suppress the proliferation and survival of RCC cells in vitro. In addition, RCC cell apoptosis was greatly induced and cell cycle progression was blocked in G1 phase by upregulation of LINC00961 in 786-O cells and ACHN cells. Subsequently, we found that LV-LINC00961 was able to restrain RCC cell migration and cell invasion capacity. Meanwhile, the messenger RNA and protein expression levels of epithelial–mesenchymal transition (EMT)-associated markers Slug and N-cadherin in RCC cell lines were dramatically inhibited by overexpressing LINC00961. Finally, the in vivo experiment was carried out and we observed that LINC00961 could inhibit RCC development through modulating EMT process. Taken these together, it was indicated in our study that LINC00961 was involved in RCC progression through targeting EMT pathway.