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-HSP90 DNA疫苗治疗宫颈癌及其免疫机制的研究

摘 要：［目的］ 探讨HPV16E7-HSP90 DNA疫苗用于治疗宫颈癌的疗效及其可能的免疫机制。［方法］ 建立TC-1宫颈癌细胞小鼠模型,负瘤第5d开始,随机将小鼠分为HPV16E7-HSP90 DNA疫苗组与对照组：DNA疫苗组给予DNA溶液100μl（5μg）,对照组给予磷酸盐缓冲溶液(PBS)100μl,两组均肌肉注射,每3d 1次,共4次。自负瘤第5d开始至治疗完成第8d,每3d测量肿瘤体积,绘制肿瘤生长曲线。治疗结束第8d,免疫组化方法检测小鼠肿瘤组织中CD8+ T 细胞、肿瘤细胞凋亡分子FAS的表达情况,TUNEL法检测负瘤小鼠肿瘤细胞的凋亡率。［结果］ HPV16E7-HSP90 DNA疫苗组的肿瘤生长速度明显低于PBS对照组(P＜0.05)。HPV16E7-HSP90 DNA疫苗组与对照组的小鼠宫颈癌组织中CD8+ T细胞表达的光密度平均值（MOD）分别为（8.76±1.27）vs (5.70±1.40)(P＜0.05);肿瘤细胞FAS表达的MOD值分别为(8.73±0.99) vs (5.74±1.47)(P＜0.05) ;小鼠肿瘤组织中CD8+ T 细胞与FAS的表达呈正相关(P＜0.01);HPV16E7-HSP90 DNA疫苗组与对照组小鼠肿瘤细胞的凋亡率分别为57.59% vs 13.11%(P＜0.05)。［结论］ HPV16E7-HSP90 DNA疫苗可上调肿瘤细胞FAS的表达,促进肿瘤细胞凋亡,激活机体的CD8+ T细胞的免疫反应,从而产生明显的抗肿瘤效应,有望于未来用于宫颈癌及癌前病变的免疫治疗。     

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。     

人乳头瘤病毒16型E6、E7反义RNA对人宫颈癌SiHa细胞的恶性逆转作用

背景与目的:人乳头瘤病毒16型(human papillomavirus 16,HPV16)的早期基因E6、E7可分别诱导p53的泛素化降解和pRb的高磷酸化失活,与宫颈癌的发生发展关系密切.本研究通过真核表达载体介导HPV16型E6、E7基因反义RNA在SiHa细胞中的表达,探讨反义RNA能否降低E6、E7基因的表达和诱导细胞凋亡.方法:利用pEGFP构建HPV16型E6、E7基因反义RNA的真核表达载体并转染SiHa细胞,利用RT-PCR和Western blot技术检测转染后E6、E7基因的mRNA和蛋白的变化,利用MTT法检测SiHa细胞转染后细胞增殖活性,利用流式细胞仪和激光共聚焦显微镜检测转染后细胞的凋亡情况.结果:转染携带HPV16型E6、E7反义基因的质粒后,SiHa细胞的E6、E7基因的mRNA和蛋白表达均明显下调;MTT结果显示转染后细胞的增殖活性(0.50±0.05)与转染空载体细胞(1.01±0.06)和未转染细胞(1.28±0.06)比较明显降低(P＜0.05);流式细胞仪检测结果显示转染后细胞凋亡率(59.3±11.3)%与转染空载体细胞(9.4±1.8)%和未转染细胞(2.1±0.4)%比较有显著性差异(P＜0.05).激光共聚焦显微镜结果示转染后细胞凋亡明显增多.结论:HPV16型E6、E7基因反义RNA可降低宫颈癌细胞中E6、E7癌基因的表达,诱导宫颈癌细胞凋亡.     

增殖诱导配体小干扰RNA对人结直肠癌裸鼠移植瘤细胞增殖和凋亡的影响

目的 研究增殖诱导配体(APRIL)小干扰RNA(siRNA)对人结直肠癌裸鼠移植瘤细胞增殖和凋亡的抑制作用.方法 建立人结直肠癌裸鼠移植瘤模型,将裸鼠分为3组,瘤块内分别注射APRIL siRNA、空载体和PBS液,每2天注射1次,共2周.采用实时荧光定量PCR法和免疫组化SP法检测APRIL siRNA对APRILmRNA和蛋白表达的影响,采用酶联免疫吸附(ELISA)法检测肿瘤内增殖细胞核抗原(PCNA)含量的变化,采用免疫组化SP法检测肿瘤内bcl-2和bcl-xl蛋白的表达,采用原位末端标记(TUNEL)法检测肿瘤细胞的凋亡.结果 APRIL siRNA能敲低APRIL基因的表达水平,APRIL siRNA组移植瘤内APRIL mRNA的相对表达量为(0.13 ±0.05)×10-3,明显低于空载体组[(0.95 ±0.04)× 10-3]和空白对照组[(0.96±0.05)×10-3,P＜0.05].APRIL siRNA组APRIL蛋白的表达比空载体组和空白对照组降低了(87.5%±5.0%,P＜0.05).APRILsiRNA组裸鼠移植瘤生长缓慢,瘤块重量较空载体组和PBS对照组明显降低(P＜0.05).APRIL siRNA组移植瘤内PCNA的含量为(176.8±18.1)ng/ml,明显低于空载体组[(330.0±20.5)ng/ml]和空白对照组[(328.4±22.8)ng/ml,P＜0.05];bcl-2和bcl-xl蛋白的表达量也较空载体组和空白对照组明显降低(P＜0.05).APRIL siRNA组移植瘤内凋亡细胞的数量增多,凋亡率为40.1%±2.5%,明显高于空载体组(2.5%±0.1%)和空白对照组(2.5%±0.2%,P＜0.05).结论 APRIL siRNA能在裸鼠体内抑制人结直肠癌细胞的增殖,并促进细胞凋亡,达到显著的抑瘤效果.APRIL基因可能成为人结直肠癌基因靶向沉默治疗的重要候选基因之一.     

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。     

RNA干扰技术裸鼠体内沉默缺氧诱导因子1α的表达对宫颈癌的抑瘤效应

目的 观察体内沉默缺氧诱导因子1α(HIF-1α)的表达后对宫颈癌的抑瘤效应,并探讨其可能的机制.方法 将实验用宫颈癌Siha细胞分为空白对照组(转染空载体)、无关对照组(转染无关对照质粒)和实验组(稳定转染pU-HIF-1α-shRNA的真核表达载体),接种裸鼠,建立裸鼠荷瘤模型,观测HIF-1α-shRNA对裸鼠皮下移植瘤的生长抑制作用.采用免疫组化SP法和Western blot 法,检测HIF-1α和葡萄糖转运蛋白1(GLUT1)蛋白在肿瘤组织中的表达.采用逆转录聚合酶链反应(RT-PCR)法,检测HIF-1α、GLUTI和己糖激酶Ⅱ(HKⅡ)mRNA的表达.采用酶显色法,检测肿瘤组织中的乳酸含量.采用原位末端标记(TUNEL)法,检测细胞凋亡.结果 实验组裸鼠肿瘤的生长速度较空白对照组和无关对照组明显减慢(P＜0.05).接种50 d后处死裸鼠,实验组裸鼠的肿瘤重量为(1.90±0.28)g,也明显轻于空白对照组[(2.95±0.77)g]和无关对照组[(2.54±0.56)g,P＜0.01].实验组肿瘤组织中HIF-1α mRNA和蛋白的相对表达量分别为0.45±0.04和1.25±0.92,GLUT1mRNA和蛋白的相对表达量分别为0.32±0.02和1.25±0.48,均明显低于空白对照组和无关对照组(均P＜0.05).实验组中HK Ⅱ mRNA和乳酸的含量均明显低于空白对照组和无关对照组(均P＜0.05),但凋亡细胞数较空白对照组和无关对照组明显增多(均P＜0.01).结论 以HIF-1α为靶点的基因治疗,可通过下调靶基因GLUT1和HKⅡ的表达来降低宫颈癌Siha细胞的糖酵解水平,促进肿瘤细胞凋亡,从而发挥抑制宫颈癌生长的作用.     

阿霉素长循环热敏脂质体的研制及其靶向治疗肿瘤作用的研究

目的: 观察人乳头瘤病毒16型(HPV)E6/E7融合蛋白疫苗与放疗(12 Gy)联合应用对宫颈癌的治疗效果.方法:24只雌性C57BL/6小鼠右侧后肢接种肿瘤细胞后7 d,随机分为4组:对照组(C,n=6);免疫组(IM,n=6);放疗组(RA,n=6);联合治疗组(IM RA,n=6).比较各组小鼠的肿瘤生长速度及存活时间.采用TUNEL法对小鼠肿瘤组织中细胞的凋亡情况进行检测.结果: IM RA组小鼠肿瘤生长速度较慢,平均存活时间明显长于RA、IM及C组,IM组与C组动物的平均存活时间没有差异.TUNEL实验结果表明,IM RA组小鼠肿瘤组织中凋亡细胞明显高于其他各组.结论: HPV16E6/E7融合蛋白疫苗与放疗联合应用,具有协同抗肿瘤作用.     

p53、人半翼基因在宫颈癌前病变及宫颈癌中的表达及相关性分析

目的 探讨p53、人半翼基因(hWAPL)在宫颈癌前病变及宫颈癌中的表达及相关性.方法 选取67例低级别宫颈上皮内瘤变(CIN)患者(CINⅠ)、58例高级别CIN患者(CINⅡ～Ⅲ)、42例宫颈癌患者和39例宫颈炎患者,取相应的CIN组织、宫颈癌组织和正常宫颈组织,免疫组化法检测HPV16/18型E6、p53、hWAPL蛋白的表达情况.根据人乳头瘤病毒(HPV)感染情况,206例患者中合并HPV感染117例,未合并HPV感染89例,比较合并与未合并HPV感染宫颈癌患者p53、hWAPL蛋白表达情况,探讨HPV感染与p53、hWAPL蛋白阳性表达的相关性.结果 HPV16/18型E6、p53、hWAPL蛋白在正常宫颈组织、CINⅠ组织、CINⅡ～Ⅲ组织和宫颈癌组织中阳性表达率和阳性表达强度逐渐升高,正常宫颈组织﹤CINⅠ组织﹤CINⅡ～Ⅲ组织﹤宫颈癌组织(P﹤0.01).合并HPV感染患者p53、hWAPL蛋白的阳性表达率均明显高于未合并HPV感染患者(P﹤0.05).Spearmen相关性分析结果显示,宫颈组织中HPV16/18型E6蛋白的阳性表达与p53、hWAPL蛋白的阳性表达均呈正相关(r=0.635、0.701,P﹤0.01),宫颈组织中p53蛋白的阳性表达与hWAPL蛋白的阳性表达呈正相关(r=0.763,P=0.000).结论 合并HPV感染的宫颈癌患者宫颈癌组织中p53?hWAPL的阳性表达率和表达强度均较高,HPV16/18型E6蛋白的阳性表达与p53?hWAPL蛋白的阳性表达均呈正相关.     

HPV16型E6、E7变异与宫颈癌发生发展的研究进展

宫颈癌是全球15 ～44岁女性中第二常见的恶性肿瘤,每年的死亡人数约为265 653人,在中国,宫颈癌的发生率及死亡率仍较高.高危型人乳头状瘤病毒(HPV)持续感染是宫颈癌前病变及宫颈癌发生的必要条件,HPV16是最常见的高危人乳头瘤病毒.HPV16编码的E6和E7蛋白在HPV相关的肿瘤中起关键作用.近年来的研究揭示了HPV16 E6、E7基因的变异引起氨基酸变化可影响E6、E7蛋白与p53、pRb 的结合,进而与宿主细胞恶性转化相关.本文将对近年来HPV16 E6、E7变异在宫颈癌发生发展中的作用作一综述.     

Plasmid-based E6-specific siRNA and co-expression of wild-type p53 suppresses the growth of cervical cancer in vitro and in vivo

The E6 protein of the oncogenic HPV-16 functions by interfering with the normal cell cycle control mechanisms, particularly those controlled by p53. In this study, we developed a dual expression plasmid that coexpressed-E6-specific siRNA and wild type p53, and to evaluate its effects on cervical cancer growth. We found that simultaneous expression of pSi-E6-P53 caused a robust suppression of tumor growth when compared to the controls either E6-specific siRNA or p53 alone. In conclusion, our findings demonstrate that a combined strategy of co-expressed E6-specific siRNA and p53 synergistically and more effectively suppressed cervical tumor growth when compared with single treatment.     

Therapeutic potential of an adenovirus expressing p73 beta, a p53 homologue, against human papilloma virus positive cervical cancer in vitro and in vivo

Human papilloma virus (HPV) infection is the most important risk factor for cervical cancer development. p53 based gene therapy is not suitable for cervical cancer because HPV oncoprotein E6 inactivates p53 protein by targeting it for ubiquitin mediated degradation. Here we evaluated the efficiency of Ad-p73, a replication deficient adenovirus expressing p73beta a p53 homologue, to inhibit the growth of HPV positive cervical cancer cells in vitro using tissue culture system and in vivo using human xenografts in nude mice. Ad-p73, but not Ad-p53 (p53 adenovirus), inhibited the growth in vitro of three different HPV positive cervical cancer cell lines, HeLa, ME180, and SiHa, efficiently, which correlated with stable expression of functional p73 protein. However, the growth of a HPV negative cervical cancer cell line, C33A, was inhibited equally by both Ad-p73 and Ad-p53. In addition, we show that Ad-p73 preinfected HeLa cells and HCT116 E6 cells, an E6 stable cell line, failed to form tumors in nude mice unlike Ad-p53 or Ad-LacZ preinfected cells. Moreover, Ad-p73, but not Ad-p53, inhibited completely the growth of already established tumors of HeLa or HCT116 E6 cells. Furthermore, the ability of p73 to inhibit the growth of these tumors correlated with the stable expression of p73 protein with the concomitant induction of its target gene p21(WAF1/CIP1) and induction of apoptosis in tumor cells. These results suggest that Ad-p73 inhibits efficiently the growth in vitro and tumorigenicity and tumor growth in vivo of HPV positive cervical cancer cells and that p73-based approach should be explored as a potential therapeutic model for the treatment of cervical cancer.     

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.     

New highly potent and specific E6 and E7 siRNAs for treatment of HPV16 positive cervical cancer

Persistent infection by high-risk types of human papillomaviruses (HPV) is a necessary cause of cervical cancer, with HPV16 the most prevalent, accounting for more than 50% of reported cases. The virus encodes the E6 and E7 oncoproteins, whose expression is essential for maintenance of the malignant phenotype. To select efficacious siRNAs applicable to RNAi therapy for patients with HPV16+ cervical cancer, E6 and E7 siRNAs were designed using siDirect computer software, after which 10 compatible with all HPV16 variants were selected, and then extensively examined for RNAi activity and specificity using HPV16+ and HPV16-cells. Three siRNAs with the highest RNAi activities toward E6 and E7 expression, as well as specific and potent growth suppression of HPV16+ cancer cells as low as 1 nM were chosen. Growth suppression was accompanied by accumulation of p53 and p21(WAF1/CIP1), as well as morphological and cytochemical changes characteristic of cellular senescence. Antitumor activity of one of the selected siRNAs was confirmed by retarded tumor growth of HPV16+ cells in NOD/SCID mice when locally injected in a complex with atelocollagen. Our results demonstrate that these E6 and E7 siRNAs are promising therapeutic agents for treatment of virus-related cancer.     

The synergistic therapeutic effect of cisplatin with Human papillomavirus E6/E7 short interfering RNA on cervical cancer cell lines in vitro and in vivo

Human papillomavirus (HPV) types 16 and 18 are the major etiologic factors in the development of cervical epithelial neoplasia. Our study was designed to validate antiviral short interfering RNA (siRNA) targeting the E6 and E7 oncogenes as a potential chemosensitizer of cisplatin (cis-diaminedichloroplatinum II; CDDP) in cervical carcinoma. Specifically, the therapeutic efficacy of combination of CDDP and E6/E7-specific siRNA was assessed in an in vivo cervical cancer xenograft models. The combination of CDDP and E6/E7-specific siRNA had greater efficacy than the combination of CDDP and E6-specific siRNA especially in terms of inducing cellular senescence. Through in vitro and in vivo experiments, the mechanism of synergy between these two treatments was revealed, demonstrating that the combination of E6/E7-specific siRNA and CDDP therapy was significantly superior to either modality alone. In vitro, long-term exposure of HeLa cells to the combination of CDDP and E6/E7-specific siRNA induced apoptosis and cellular senescence. In vivo, E6/E7-specific siRNA potentiated the antitumor efficacy of CDDP via induction of apoptosis, senescence and antiangiogenesis. Our results suggest that E6/E7-specific siRNA may be an effective sensitizer of CDDP chemotherapy in cervical cancer.     

短发夹状RNA抑制子宫颈癌CaSki细胞HPV 16 E7基因的研究

目的：研究短发夹状RNA（short hairpin RNA，shRNA）构建的人乳头瘤病毒（human papillomavirus，HPV）16E7siRNA表达载体转染宫颈癌细胞株CaSki细胞后，在体内外对CaSki细胞E7基因的抑制作用。方法：利用脂质体将构建有HPV16E7特异性小干扰RNA（small interfering RNA，siRNA）的表达载体P1、P2、P3转染CaSki细胞，以实时荧光定量RT—PCR及流式细胞仪检测不同时间点E7mRNA和蛋白的变化，并将载体P1转染后的细胞接种到裸鼠皮下，4周后观察裸鼠体内皮下移植瘤体积和质量的差异，并用免疫组化检测瘤体组织中E7蛋白的表达变化。结果：表达载体P1、P2、P3均能抑制Caski细胞E7mRNA和蛋白的表达。其中载体P1抑制作用最强，在抗性克隆形成后1周，对E7mRNA和蛋白的抑制率分别为92．86％、84．21％；在抗性克隆形成后4周，抑制率仍分别为68．95％、62．50％。在接种后4周载体P1组裸鼠体内皮下移植瘤的体积和重量明显小于空载体组和对照组，同时E7蛋白的表达也被有效抑制，抑制率为74．75％。结论：构建有shRNA的E7siRNA表达载体在体内外可明显抑制E7基因的表达。     

The human papillomavirus E6 and E7 inducible oncogene, hWAPL, exhibits potential as a therapeutic target

Here we show that human papillomavirus (HPV) E6 and E7 oncoproteins induce hWAPL expression. In addition, small interfering RNA (siRNA) of hWAPL suppressed the growth of tumours derived from SiHa cells in nude mice. Thus, hWAPL may be one of the effective targets of uterine cervical cancer therapy.     

Human papillomavirus 16 E6, E7 siRNAs inhibit proliferation and induce apoptosis of SiHa cervical cancer cells

Objective:To evaluate the effects of HPVI6 E6/E7 siRNAs on cervical cancer SiHa cells.Methods:The expressions of the E6,E7,p53 and Rb genes were assayed by RT-PCR and Western-bloting respectively.The proliferation and apoptosis of the cells were evaluated by MTT and flow cytometry.Results:HPV 16 E6 and E7 oncogenes were selectivly downregulated by HPV 16 E6 and E7 siRNAs,which sustained at least 96 h by single dose siRNA.Furthermore,reduction of E6 and E7 oncogenes expression upregulated the expressions ...     

Intratumor injection of small interfering RNA-targeting human papillomavirus 18 E6 and E7 successfully inhibits the growth of cervical cancer

Human papillomavirus (HPV) 18 is related not only to squamous cell carcinoma of the cervix, but also to adenocarcinoma and small cell carcinoma of the cervix, in which prognosis is known to be poor. Small interfering RNA (siRNA) that targets HPV18 E6 and E7 was tested in HPV18-positive cell lines to investigate its effect and investigate its mechanism of action. Nude mice were also tested in a combination of siRNA and atelocollagen to determine whether it might be useful as a new molecule-targeting therapy for cervical cancer. siRNAs targeting HPV18 E6 and E7 were transfected into cervical cancer cells in vitro and they were investigated for cell growth inhibition, expression of E6 and E7 mRNA, expression of retinoblastoma protein, and senescence-associated beta-galactosidase staining. Sequence-specific siRNA inhibited cell growth. Decreased expression of E6 and E7 mRNA followed with E7 protein was observed in the transfected cells, but the expression of retinoblastoma protein and the beta-galactosidase staining increased, suggesting cell growth inhibitory effect through senescence. Treatment of xenografts established from SKG-II cells with siRNA specific for E6 and E7 obviously suppressed tumor growth in vivo. These results indicate that atelocollagen-mediated delivery of siRNA HPV18 E6 and E7 can be used as a novel therapeutic approach for cervical cancer.