摘要目的 探讨Bcl-2结合抗凋亡基因3(BAG3)在子宫颈癌组织和细胞中的表达以及对子宫颈癌上皮间质转化(EMT)的作用及其机制.方法 (1)收集2015年9月至2017年3月山东大学齐鲁医院和附属省立医院病理科保存的子宫颈癌标本50份,以2015年8月至2017年3月德州市立医院妇科收治的因子宫肌瘤行子宫全切除术或行子宫颈活检患者的正常子宫颈组织50份作为对照,分别采用逆转录(RT)-PCR技术和蛋白印迹(western blot)法检测BAG3 mRNA和蛋白的表达并分析其临床意义.(2)选择子宫颈癌细胞系HeLa和SiHa细胞,以正常子宫颈上皮细胞为对照,分别采用RT-PCR技术和western blot法检测细胞中BAG3 mRNA和蛋白的表达;以下实验分为两组,即转染组[转染BAG3基因的小分子干扰RNA(si-BAG3)]和对照组[转染对照小分子干扰RNA(siRNA)],采用活细胞计数(CCK-8)法检测转染后两组HeLa和SiHa细胞的增殖情况[以吸光度(A)值表示];体外划痕实验和transwell小室实验检测转染后两组HeLa和SiHa细胞的迁移、侵袭能力(分别以愈合率和穿膜细胞数表示);建立两组子宫颈癌HeLa和SiHa细胞的裸鼠移植瘤模型,观察BAG3对移植瘤成瘤的影响,并采用western blot法检测移植瘤组织中EMT相关生物标志物[包括锌指转录因子(Slug)、基质金属蛋白酶2(MMP-2)、神经型钙黏蛋白(N-cadherin)、上皮型钙黏蛋白(E-cadherin)]蛋白的表达.结果 (1) RT-PCR技术和western blot法分别检测显示,子宫颈癌组织中BAG3 mRNA和蛋白的表达水平分别为1.20±0.15、1.10±0.16,明显高于正常子宫颈组织(分别为0.23±0.04、0.29±0.03,P均＜0.01);子宫颈癌组织中BAG3 mRNA和蛋白的表达水平与临床分期、淋巴结转移状态均明显相关(P＜0.05),而与患者的年龄、病理分级、肿瘤直径均无相关性(P＞0.05).(2)RT-PCR技术和western blot法分别检测显示,与正常子宫颈上皮细胞比较,HeLa和SiHa细胞中BAG3 mRNA和蛋白表达水平均明显增高(P均＜0.01);转染组HeLa和SiHa细胞中BAG3 mRNA和蛋白表达水平均明显低于对照组(P均＜0.01).CCK-8法检测显示,转染后72 h,转染组HeLa和SiHa细胞的A值分别为0.88±0.08、0.92±0.09,明显低于对照组(分别为1.22±0.13、1.35±0.12,P均＜0.01);体外划痕实验检测显示,转染组HeLa和SiHa细胞的愈合率分别为(20.1±2.1)％、(21.1±2.1)％,均明显低于对照组[分别为(58.6±5.6)％、(61.7±5.4)％,P均＜0.01];体外transwcll小室实验检测显示,转染组HcLa和SiHa细胞的穿膜细胞数分别为(76±11)、(71±8)个,均明显少于对照组[分别为(131±12)、(129±14)个,P均＜0.01].裸鼠在接种转染组HeLa和SiHa细胞后的成瘤时间分别为(9.5±0.5)、(10.5±1.3)d,明显长于接种对照组HeLa和SiHa细胞后的成瘤时间[分别为(4.5±0.5)、(5.2±1.1)d,P均＜0.05];与接种对照组HeLa和SiHa细胞的裸鼠相比,接种转染组HeLa和SiHa细胞的裸鼠移植瘤组织中Slug、MMP-2和N-cadherin蛋白的表达水平均明显下降(P均＜0.01),E-cadherin蛋白的表达水平均明显升高(P均＜0.01).结论 BAG3 mRNA和蛋白在子宫颈癌组织和细胞中均高表达;BAG3通过影响子宫颈癌EMT的发生进而参与子宫颈癌细胞的增殖、迁移与侵袭过程,因而BAG3有望成为子宫颈癌治疗的有效靶点.

abstractsObjective To investigate the expression of Bcl-2 associated athanogene 3 (BAG3) in cervical cancer tissues and cells and its role in epithelial mesenchymal transition (EMT) of cervical cancer.Methods (1) Cervical cancer samples were collected from September 2015 to March 2017 in the Qilu Hospital of Shandong University and Shangdong Provincial Hospital.While,50 normal tissues were collected from August 2015 to March 2017 in the Dezhou Municiple Hospital,which were obtained from patients with uterine mnyoma underwent hysterectomy and patients with cervical biopsy.Reverse transcription (RT)-PCR and western blot were used to detect the expression of BAG3 mRNA and protein,and their clinical significances were analyzed.(2) The expression of BAG3 mRNA and protein was detected using RT-PCR and western blot method in HeLa and SiHa cell lines and normal cervical epithelial cells.The experiment was divided into two groups,BAG3 small interfering RNA transfected group (st-BAG3) and the control group transfected with small interfering RNA (siRNA).Cell counting kit 8 (CCK-8) analysis was used to detect cell proliferation of two groups.Wound-healing and transwell assay were used to detect the migration and invasion ability of HeLa and SiHa cells.The xenograft model of cervical cancer in nude mice was used to observe the effect of BAG3 on tumor xenografts and the tumor-related biomarkers were tested by western blot.Results (1) The expression levels of BAG3 mRNA and protein in cervical carcinoma tissues were 1.20±0.15 and 1.10±0.16,which were significantly higher than that in normal cervical tissue,0.23± 0.04 and 0.29 ± 0.03 (both P＜0.01).The results showed that the expression levels of BAG3 mRNA and protein were significantly correlated with cervical carcinoma staging and lymph node metastasis (P＜0.05).However,its expression was not conrelated with the patient's age,pathological grade,and diameter of tumor (all P＞0.05).(2) Compared with normal cervical epithelial cells,the expression of BAG3 mRNA and protein levels in HeLa and SiHa cells were significantly increased (P＜0.01),the expression levels of BAG3 mRNA and protein in HeLa and SiHa cells transfected with si-BAG3 were significantly lower than that in control group (all P＜0.01).After post-transfected 72 hours,A value of HeLa and SiHa with transfection were significantly lower than those in control group [(0.88±0.08) vs (1.22±0.13),(0.92±0.09) vs (1.35±0.12);both P＜0.01].After post-transfected 24 hours,the migration level of HeLa and SiHa cells with transfection were significantly lower than those in the control group [(20.1±2.1)％ vs (58.6±5.6)％,and (21.1±2.1)％ vs (61.7± 5.4)％;both P＜0.01].The transmembrane cell number in HeLa and SiHa cells with transfection were 76± 11 and 71±8,which were significantly less than those in control group (131± 12 and 129± 14;both P＜0.01).After the inoculation into nude mice,tumor formation time of HeLa and SiHa cells with transfection were (9.5±0.5) and (10.5 ± 1.3) days,respectively,which were significantly longer than those in control group [(4.5±0.5) and (5.2± 1.1) days;both P＜0.05].Compared with those in the control group,the expression level of Slug,N-cadherin and matrix metalloproteinase-2 (MMP-2) protein in HeLa and SiHa cells with transfected in tumor tissues were significantly decreased (all P＜0.01),while the expression level of E-cadberin protein was significantly increased (P＜0.01).Conclusion BAG3 could be involved in the proliferation,migration and invasion of cervical cancer cells by affecting cervical cancer EMT,and BAG3 may be an effective target for the treatment of cervical cancer.