HPV18E6基因沉默对宫颈癌Hela细胞生长和凋亡的影响

目的：观察RNA干扰法沉默HPV18E6基因表达对宫颈癌Hela细胞牛长和凋亡的影响，探索宫颈癌基因治疗的新途径。方法：针对HPV18E6 mRNA序列合成一对60bp的编码siRNA的DNA模板和一对60bp的非特异性对照DNA模板，构建pSUPER—siRNA和pSUPER—com重组质粒，瞬时转染Hela细胞；采用RT—PCR法检测质粒转染后细胞HPV18E6基因表达的变化，用蛋白免疫印迹法检测转染后Hela细胞p53、p21、Bcl-2和Bax蛋白表达变化，以细胞计数法检测细胞生长情况，Hoechest／PI双荧光活细胞染色法检测细胞凋亡。结果：pSUPER—siRNA质粒转染能有效降低HPV18E6在mRNA水平的表达，转染后48小时，抑制效率达70％以上；转染后细胞053、p21和Bax蛋白表达显著增加，Bcl-2蛋白表达减少。RNA干扰法沉默HPV18E6基因表达后，Hela细胞增殖受到明显抑制，细胞凋亡率明显增加。结论：pSUPER—siRNA质粒转染可有效抑制HPV18E6在人宫颈癌Hela细胞中的表达，抑制Hela细胞生长并促进其凋亡。以HPV18E6为靶点的RNA干扰技术可望成为宫颈癌基因治疗的新途径。     

HPV18 E6E7 反义荧光真核表达载体的构建及其在宫颈癌HeLa 细胞中的表达

 目的 构建HPV18型E6E7反义荧光真核表达载体,并观察其对宫颈癌HeLa细胞中HPV18 E6和E7基因表达的影响,探索反义技术用于治疗临床HPV感染及宫颈癌的可能性。方法 以HPV18型全基因质粒为模板,PCR法扩增HPV18型E6E7区716bp片段,利用基因重组技术将目的片段反向插入荧光真核表达载体pEGFP-C1,EcoR I酶切并测序鉴定;采用脂转法将重组质粒pEGFP-HPV18 E6E7as（EGFP-18AS）转染宫颈癌HeLa细胞株,通过RT-PCR及western blot检测细胞中E6、E7 mRNA和蛋白的表达。结果 成功构建HPV18E6E7反义荧光真核表达载体EGFP-18AS,经脂质体转染HeLa细胞,48h后在荧光倒置显微镜下可见明显的绿色荧光,且细胞中E6、E7 mRNA及蛋白表达水平均明显下调。结论 反义荧光真核表达载体可以有效的抑制HPV18E6、E7癌基因的表达,为治疗HPV感染和宫颈癌提供了一种新的方法。     

小干扰RNA抑制宫颈癌Hela细胞株HPV18 E6、E7基因的表达

目的:以人乳头瘤病毒(human papillomavirus,HPV)18型E6基因为靶点,研究小干扰RNA(small interference RNA,siRNA)对宫颈癌Hela细胞株HPV18基因组中恶性转化基因E6、E7的抑制作用及对细胞内P53蛋白表达的影响。方法:实验分细胞培养液阴性对照组(阴性对照组),无关序列siRNA对照组(无关序列对照组)及转染HPV18 E6-siRNA实验组(siRNA实验组)。设计并合成HPV18 E6-siRNA及无关序列siRNA,转染Hela细胞后,RT-PCR检测转染后48、120 h细胞内HPV18E6、E7mRNA的变化,Western blotting检测转染后48 h细胞内HPV18 E7和P53蛋白的变化。结果:siRNA转染Hela细胞的效率约为85%。siRNA转染后48 h,实验组细胞内HPV18E6、E7mRNA及E7蛋白含量降低,其含量分别为阴性对照组的33.33%、36.78%及33.84%;实验组细胞内P53蛋白含量增加,其含量为阴性对照组的2.194倍。siRNA转染后120 h,实验组细胞HPV18E6、E7mRNA含量恢复为阴性对照组的90.91%、101.60%。结论:HPV18 E6-siRNA体外能明显抑制宫颈癌Hela细胞HPV18E6、E7基因的表达,增加细胞内肿瘤抑制因子P53蛋白的水平。     

HPV16E7基因沉默对宫颈癌细胞系CaSki细胞增殖的影响

[目的]探讨脂质体转染HPVl6E7siRNA对人宫颈癌CaSki细胞增殖的影响。[方法]人工合成抑制HPVl6E7基因的siRNA片段,通过脂质体转染到CaSki细胞内,显微镜下观察其形态学变化;流式细胞术检测各组细胞周期变化;RT-PCR检测HPVl6E7mRNA的表达;Westernblot检测HPVl6E7蛋白表达。[结果]转染siRNA后的CaSki细胞,细胞增殖受到显著抑制．HPVl6E7mRNA表达显著下降,HPVl6E7蛋白水平显著下降。[结论]应用RNA干扰靶向抑制HPVl6E7基因可以显著抑制CaSki细胞增殖。     

Induction of cell death in human papillomavirus 18-positive cervical cancer cells by E6 siRNA

Human cervical cancer is caused by high-risk types of human papillomavirus (HPV) such as HPV16 and HPV18, which possess the E6 and E7 oncogenes, whose concurrent expression is a prerequisite for cancer development and maintaining malignant phenotypes. Silencing these oncogenes is considered to be applicable in molecular therapies of human cervical cancer. However, it remains to be determined whether E6, E7, or both should be silenced to obtain most efficient antitumor activity by an HPV small-interfering RNA (siRNA). Herein, we report two types of siRNAs targeting HPV18 E6, that exerted a negative growth effect on HPV18-positive cervical cancer cells (HeLa and SW756), in part, inducing cell death. One siRNA (Ex-18E6), designed to target both E6-E7 mRNA and its splicing variant, E6*I-E7 mRNA, efficiently knocked down both E6 and E7 expression. The other (Sp-18E6), designed to specifically target E6-E7 mRNA but not E6*I-E7 mRNA, suppressed E6 to a similar level as Ex-18E6; however, it less efficiently inhibited E7 as compared to Ex-18E6. Although both siRNAs induced cell death, Sp-18E6 siRNA induced more prominent cell death than Ex-18E6. Our results suggest that E6-specific suppression may induce more potent anticancer activity than simultaneous E6 and E7 suppression, and that E6-specific targeting is a promising strategy for siRNA-based therapy for HPV-positive cervical cancer.     

Down-regulation of HPV18 E6, E7, or VEGF expression attenuates malignant biological behavior of human cervical cancer cells

To investigate the effect of down-regulation of VEGF (vascular endothelial growth factor) and HPV18 E6/E7 by hairpin RNA (shRNA) on cell proliferation, apoptosis, migration, invasion, and adhesion abilities of cervical carcinoma cells, recombinant plasmids including pS-E6 shRNA, pS-E7 shRNA, and pS-VEGF shRNA were constructed and transfected into HeLa cells. The levels of E6 mRNA, E7 mRNA, or VEGF mRNA were significantly reduced after transfection of pS-E6 shRNA (76.0%), pS-E7 shRNA (74.4%), and pS-VEGF shRNA (46.7%). VEGF expression was down-regulated by pS-E6 shRNA (55.1%) and pS-E7 shRNA (46.6%). The apoptosis of HeLa cells was increased, and the proliferation, invasion, and adhesion abilities were decreased significantly. For in vivo study, cancer cells that stably expressed the plasmids were cultured. Cells were transplanted subcutaneously into nude mice to establish xenograft tumor model. Finally, expression of E6 shRNA, E7 shRNA, and VEGF shRNA in cancer cells led to inhibition of the growth of xenograft. Hence, RNA interference could effectively suppress the expression of HPV18 E6/E7 and VEGF in human cervical cancer cells. This suppression attenuates malignant biological behavior of human cervical cancer cells. RNA interference of HPV E6/E7 or VEGF expression implies an effective anti-cervical cancer strategy.     

靶向HPV18E6基因siRNA对HeLa细胞p21、VEGF、Bax 和Bcl-2基因的影响

 目的 探讨针对人乳头瘤病毒18型E6基因的特异性小干扰RNA（siRNA）对宫颈癌HeLa细胞p21、VEGF、Bax和Bcl-2基因的影响。 方法 采用脂质体法将特异性siRNA瞬时转染HeLa细胞,半定量RT-PCR检测siRNA转染后HeLa细胞中p21、血管内皮生长因子（VEGF）、Bax和Bcl-2 mRNA的变化,免疫组化检测HeLa细胞中p21和VEGF蛋白的变化。 结果 RT PCR检测结果显示转染后24、48、 72h p21和Bax mRNA的表达与转染前比较均有升高。转染后24、48、72h VEGF和Bcl-2 mRNA的表达与转染前比较均有降低。免疫组化检测结果显示转染后48、72h p21蛋白的表达与转染前比较均有升高。转染后48、72h VEGF蛋白的表达与转染前比较均有降低。 结论 靶向HPV18 E6基因的siRNA可有效干扰宫颈癌HeLa细胞中p21、VEGF、 Bax和Bcl-2基因的表达,从而抑制细胞增殖。     

宫颈癌细胞系中HPV16 E6、E7及E6/E7基因对STK31基因甲基化状态及表达的影响

背景与目的：丝氨酸/苏氨酸蛋白激酶31(serine/threonine kinases 31,STK31)基因在人类多种癌症中扮演重要角色,且STK31基因的表达受其启动子及第一外显子区甲基化状态的影响;病毒感染与肿瘤组织中某些抑癌基因启动子区高甲基化有关。本研究旨在探讨宫颈癌细胞系中HPV16 E6、E7及E6/E7癌基因对STK31基因甲基化状态及表达的影响,以及不同种类甲基转移酶(DNA methyltransferases,DNMTs)基因在STK31基因甲基化中的潜在作用。方法：构建外源性HPV16 E6、E7以及E6/E7基因共表达慢病毒,分别感染人乳头瘤病毒(human papillomavirus,HPV)阴性宫颈癌细胞系HT-3及C33A,获得稳定转染的细胞系;采用亚硫酸氢盐基因组测序法(bisulfite genomic sequencing,BGS)和甲基化特异性PCR (methylation-specific PCR,MSP)检测3种HPV阳性宫颈癌细胞系HeLa、SiHa和CasKi以及HPV阴性宫颈癌细胞系HT-3和C33A转染前后STK31基因的甲基化状态;RT-PCR及蛋白［质］印迹法(Western blot)检测上述宫颈癌细胞系中STK31基因的表达以及DNMT1、DNMT2、DNMT3a、DNMT3b和DNMT3L基因在HPV16转染前后宫颈癌细胞系及HPV阳性、HPV阴性宫颈癌组织中的表达情况。结果：外源性HPV16 E6、E7以及E6/E7基因可在HPV阴性宫颈癌细胞系中稳定表达。3种HPV阳性细胞系HeLa、SiHa和CasKi中STK31基因呈低甲基化状态,STK31 mRNA及蛋白质表达阳性;2种HPV阴性细胞系HT-3、C33A中STK31基因则表现为高甲基化状态,STK31 mRNA及蛋白质表达缺失;与未感染慢病毒HT-3和C33A细胞系比较,外源性HPV16 E7以及E6/E7表达的HT-3和C33A细胞系STK31基因甲基化程度降低,其mRNA及蛋白质重新表达。DNMT1、DNMT3a和DNMT3b基因在HT-3E6/E7和C33AE6/E7细胞系中mRNA水平分别高于HT-3空载细胞系和C33A空载细胞系,差异有统计学意义(P<0.001)。DNMT1、DNMT3a和DNMT3b基因的mRNA水平在HPV16阳性宫颈癌组织中的表达高于其在HPV阴性宫颈癌组织中的表达,差异有统计学意义(t=5.997,P<0.001;t=6.743,P<0.001;t=7.926,P<0.001)。DNMT2在HT-3E6/E7和C33AE6/E7细胞系中mRNA表达水平分别低于HT-3空载细胞系和C33A空载细胞系,差异有统计学意义(t=7.451,P<0.001;t=2.451,P<0.05);DNMT2基因转录水平在HPV16阳性宫颈癌组织中低于HPV阴性宫颈癌组织(t=9.134,P<0.001)。DNMT3LmRNA表达水平在宫颈癌细胞系转染前后及HPV阴阳性宫颈癌组织中的差异无统计学意义(P>0.05)。结论：HPV感染可导致STK31基因启动子及第1外显子区甲基化状态降低,低甲基化状态促进该基因表达。STK31基因的表达受其启动子及第1外显子区甲基化状态的调控。HPV16 E7、E6/E7基因可能通过影响DNMT2的表达参与调控癌基因STK31基因启动子及第1外显子区甲基化状态。     

HPV16E7 siRNA表达载体抑制宫颈癌SiHa细胞E7基因的研究

目的：研究HPV16E7siRNA表达载体对宫颈癌SiHa细胞E7基因的抑制作用。方法：利用脂质体将HPV16E7 siRNA表达载体psiRNA-1、psiRNA-2、psiRNA-3及空载体psiRNA转染SiHa细胞,以荧光定量RT-PCR和流式细胞仪检测不同时间点E7 mRNA和蛋白的变化。结果：载体psiRNA-1、psiRNA-2和psiRNA-3均能抑制SiHa细胞E7基因 mRNA和蛋白的表达,其中载体psiRNA-1的抑制作用最强。在抗性克隆形成后1周和4周,对E7mR-NA和蛋白抑制率分别为92.15%、84.30%和65.69%、59.11%。而空载体对E7mR-NA和蛋白的表达均无明显抑制作用。结论：HPV16E7 siRNA表达载体能较长期地抑制宫颈癌SiHa细胞E7基因的表达。     

RNA干涉抑制宫颈癌 CaSki细胞株 HPV16 E6基因的研究

背景与目的：研究表明宫颈癌的发生发展与人乳头瘤病毒(human papilloma virus,HPV)E6、E7癌基因密切相关,于是人们采用核酶或HPV E6、E7反义寡核苷酸抑制其表达来治疗宫颈癌,虽然取得了一定的效果,但仍面临基因抑制效率低、维持时间短、工作量大、耗费多等问题。本研究采用最新的RNA干扰技术干扰宫颈癌CaSki细胞中HPV16 E6转录,以了解其能否特异性抑制HPV16 E6基因及其时效性如何。方法：设计合成针对HPV16 E6的荧光标记siRNA,借脂质体转染宫颈癌CaSki细胞,通过荧光照片计数荧光细胞占所有细胞的比例计算转染效率;测定转染后不同时间点的细胞凋亡率;RT-PCR测定HPV16 E6 mRNA变化,Western blot和流式细胞仪检测转染前后蛋白表达情况。结果：相差显微镜荧光照片显示细胞转染的效率为81％。HPV16 E6 siRNA转染细胞后24h、48h、5天凋亡率分别为7．7％、11．8％和37．4％,转染9天时凋亡率下降至12．6％。RT-PCR扩增结果显示,细胞转染前HPV16 E6 mRNA的量与siRNA阴性对照比较没有显著性差异,但转染后24h、48h、5天和9天分别减少了77％、83％、59％和41％;而作为内对照的β-actin mRNA在转染前后无变化。流式细胞仪定量测定HPV16 E6蛋白,结果显示转染后24h、48h和5天,蛋白表达抑制率分别为79．7％、80．4％和71．3％;9天时抑制率有下降,但仍可达57．4％。此结果与HPV16 E6 Western blot结果相吻合。以Lamin A/C作为内对照,不同的时间点Lamin A/C蛋白表达均无差异。结论：宫颈癌CaSki细胞中确实有RNA干扰现象存在,对外源性的HPV16病毒E6基因的干扰具有基因特异性和高效性。     

Highly potent and specific siRNAs against E6 or E7 genes of HPV16- or HPV18-infected cervical cancers

Infection with high-risk types (type 16 or type 18) of human papillomaviruses (HPVs) increases a patient's risk of cervical cancer. Given the importance of the cervix and the severe side effects resulting from traditional cancer therapies, this study aimed to achieve targeted inhibition of viral oncogenes in tumor cells using small interfering RNAs (siRNA). To accomplish this, we developed nine siRNAs against either the E6 or E7 genes of HPV-16 or HPV-18 in several combinations, yielding siRNAs targeting 16E6, 16E7, 18E6 and 18E7. We measured the effectiveness of the siRNAs by examining E6 or E7 mRNA expression after transfection of the siRNAs into HPV-positive CaSki (HPV-16) or HeLa (HPV-18) cell lines. We found that the HPV-siRNAs significantly reduced cell growth and colony formation in both cell lines. Flow cytometry analysis revealed a significant increase in apoptosis. The siRNAs had no effect on cell growth, colony formation or apoptosis in HPV-negative C33A cells, demonstrating a lack of off-target effects. In addition, an in vivo xenograft study showed that intra-tumoral injection of the siRNAs reduced tumor growth in BALB/c nude mice. In conclusion, we have developed highly specific and potent HPV-siRNAs that successfully suppress tumor growth and induce apoptosis in HPV-positive cervical cancer cells. siRNA treatment has potential for further development as an adjuvant therapy for cervical cancer.     

Cancerous inhibitor of protein phosphatase 2A contributes to human papillomavirus oncoprotein E7-induced cell proliferation via E2F1

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a recently identified oncoprotein that is overexpressed in many human malignant tumors including cervical cancer. Human papillomavirus (HPV) oncoprotein E7 is the key transformation factor in cervical cancer. Our previous data showed a positive association of CIP2A and HPV-16E7 protein levels; however, how CIP2A is regulated by HPV-E7 and the roles of CIP2A in HPV-E7-mediated cell proliferation are unknown. In this study, we demonstrated that HPV-16E7 protein significantly upregulating CIP2A mRNA and protein expression depended on retinoblastoma protein pRb rather than p130. CIP2A siRNA knockdown in HPV-E7-expressing cells inhibited cell proliferation, DNA synthesis and G1/S cell cycle progression. CIP2A siRNA decreased the protein levels of cyclin-dependent kinase 1 (Cdk1), Cdk2 and their partner cyclin A2, with no change in levels of Cdk4, Cdk6 and their partner cyclin D1. The downregulation of Cdk1 and Cdk2 was independent of c-Myc; instead, E2F1 was the main target of CIP2A in this process, as overexpression of E2F1 rescued the inhibitory effects of CIP2A siRNA knockdown on cell proliferation and G1 arrest of HPV-E7-expressing cells. Our studies reveal a novel function of CIP2A in HPV-16E7-mediated cell proliferation.     

TLR9 Expression in Uterine Cervical Lesions of Uyghur Women Correlate with Cervical Cancer Progression and Selective Silencing of Human Papillomavirus 16 E6 and E7 Oncoproteins in Vitro

Background: Cervical cancer is listed as one of high-incidence endemic diseases in Xinjiang. Our study aimedto evaluate the expression of TLR9 in uterine cervical tissues of Uyghur women and examine associations withclinicopathological variables. We further characterized the direct effects of TLR9 upon the selective silencing ofhuman papillomavirus (HPV) E6 and E7 oncoprotein expression in HPV 16-positive human cervical carcinomacells treated with siRNA in vitro. Materials and Methods: Immunohistochemistry was applied to evaluate TLR9expression in 97 formalin-fixed paraffin-embedded cervical samples from Uyghur women; 32 diagnosed withcervical squamous cell carcinomas (CSCC) , 14 with low-grade cervical intraepithelial neoplasias (CINI), 10medium-grade (CINII), 24 high-grade (CINIII), and 17 chronic cervicitis. BLOCK-iT™ U6 RNAi Entry VectorpENTR™/U6-E6 and E7 was constructed and transfected the entry clone directly into the mammalian cell line293FT. Then the HPV 16-positive SiHa human cervical carcinoma cell line was infected with RNAi recombinantlentivirus. RT-PCR and Western blotting were used to determine the expression of TLR9 in both SiHa and HPV16 E6 and E7 silenced SiHa cells. Results: Immunohistochemical staining showed that TLR9 expression wasundetectable (88.2%) or weak (11.8%) in chronic cervicitis tissues. However, variable staining was observed inthe basal layer of all normal endocervical glands. TLR9 expression, which was mainly observed as cytoplasmicstaining, gradually increased in accordance with the histopathological grade in the following order: chroniccervicitis (2/17, 11.8%) 相似文献   

HPV-16 E6 siRNA与hIL-24基因联合诱导人宫颈癌Ca Ski细胞的凋亡

目的：观察HPV-16 E6 siRNA与hIL-24基因体外共转染，联合诱导人宫颈癌CaSki细胞凋亡的效应。方法：HPV-16 E6 siRNA与hIL-24基因的质粒载体分别以单独或联合的方式转染入宫颈癌CaSki细胞，随后利用RT—PCR技术检测细胞中HPV-16E6癌基因的mRNA水平变化；Western blot分析细胞中抑癌蛋白p53水平的变化；流式细胞技术分析细胞凋亡情况。结果：经HPV-16 E6 siRNA和hIL-24转染后细胞后HPVE6癌基因的mRNA水平均下降，其中联合转染组显著下降（P〈0，05）；抑癌蛋白p53水平均增高，其中联合转染组显著增高，细胞凋亡率均升高，其中联合转染组显著升高（P〈0．05）。结论：HPV-16 E6siRNA与hIL-24基因分别转染宫颈癌CaSki细胞后，均能抑制CaSki细胞中HPV-16E6癌基因的表达，使抑癌蛋白p53恢复活性，诱导宫颈癌CaSki细胞凋亡；两者联合别具有协同效应，能显著提高肿瘤细胞凋亡率。     

HPV16E6 siRNA联合5-Aza-CdR对宫颈癌SiHa细胞中E-钙黏蛋白表达和基因甲基化的影响

目的:探讨HPV16E6 siRNA联合5-Aza-CdR(5-aza-2'-deoxycytidine,5-氮-2'-脱氧胞苷,又称地西他滨)对宫颈癌SiHa细胞中E-钙黏蛋白表达和基因甲基化的影响。方法:采用SiHa细胞构建的HPV16E6 沉默细胞株及5-Aza-CdR细胞株,检测细胞中E-cadherin mRNA和蛋白表达,以及E-cadherin甲基化状态。采用细胞黏附、Transwell体外侵袭、迁移实验检测5-Aza-CdR和siRNA E6对SiHa细胞黏附、侵袭迁移的影响。结果:5-Aza-CdR+siRNA E6组较5-Aza-CdR组、siRNA E6组中E-cadherin mRNA 及蛋白表达均上升,细胞的黏附率、侵袭抑制率和迁移抑制率均升高;5-Aza-CdR+siRNA E6组较5-Aza-CdR组、siRNA E6组中E-cadherin基因启动子区甲基化指数明显下降。结论:HPV16E6 siRNA联合5-Aza-CdR可显著引起宫颈癌细胞中E-cadherin 基因低甲基化,并可导致E-cadherin mRNA 及蛋白的表达水平明显上调,肿瘤细胞黏附能力升高,侵袭迁移能力下降,两者在一定程度起到协同作用。