Liao Yan-dan, Xu Hong, Han Qing, Lei Jie, Zhang Ying-ying, Wang Ze-Hua
Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
Zhonghua Zhong Liu Za Zhi. 2007 May;29(5):360-4.
To investigate the expression of Angiotensin II type 1 receptor (AT1R) in tissue and cell lines of squamous cervical carcinomas and its clinical significance, and to explore the molecular mechamisms of angiotensin II and AT1R activity in the process of cervical carcinogenesis.
(1) The levels of AT1R mRNA were examined by quantitative reverse transcriptase-polymerase chain reaction( RT-PCR) in paraffin-embedded tissues from 35 cases of cervical squamous cell carcinoma, 15 cases of cervical intraepithelial neoplasia (CIN), and 15 cases of normal cervix, and in Siha and C33a cells. The expression of AT1R protein in 65 specimens of cervix tissue sections was evaluated by immunohistochemistry. The corelation between the expressions of AT1R and its clinicopathologic features was analyzed accordingly. (2) After the Siha and C33a cells were treated at different concentrations of Angiotensin II (0, 10(-10) mol/L, 10(-9) mol/L, 10(-8) mol/L, 10(-7) mol/L, 10(-6) mol/L, 10(-5) mol/L) for different time in culture, the cell proliferation was determined by methylthiazolyl tetrazolium (MTT) assay. The vascular endothelial growth factor (VEGF) expression was examined by enzyme-linked immuno-absordent assay (ELISA).
(1) AT1R mRNA expression was detected in the two cervix cancer cell lines. The positive rate of ATIR mRNA was 77.1%, 40.0% and 0, respectively, in squamous cell carcinomas, cervical intraepithelial neoplasia and normal cervical tissues, while their mRNA quantities were 0.3863 +/- 0.041, 0.0768 +/- 0.035 and 0, respectively. There was statistically a significant difference between them (P < 0.01). The average staining intensity of AT1R protein was stronger in invasive carcinoma cells than that in dysplasia tissues and normal ones (P < 0.01). Among 65 cases of squamous cell carcinomas, the expressions of AT1R mRNA and protein increased with pathological grading (P < 0.05), while it was neither correlated with clinical stage nor pelvic lymph node metastasis (P > 0.05). The level of AT1R protein expression corresponded to that of its mRNA. (2) Angiotensin II promoted the cell growth of cervical cancer cell lines Siha and C33a and induced secretion of VEGF from cells in a dose-dependent manner (P < 0.01), and the expression of VEGF was reversed by the addition of valsatan (an antagonist of angiotensin II type 1 receptor) (P < 0.01).
Angiotensin II is involved in the progression of cervical carcinoma, since it may increase the proliferation activity of cancer cells, induce secretion of VEGF through AT1R synchronously, and results in an increase of angiogenesis in tumors. It suggests that use of AT1R antagonists may be an useful therapeutic strategy for cervical carcinoma.
探讨血管紧张素Ⅱ1型受体（AT1R）在宫颈鳞癌组织及细胞系中的表达及其临床意义，探讨血管紧张素Ⅱ及AT1R活性在宫颈癌发生过程中的分子机制。
（1）采用定量逆转录聚合酶链反应（RT-PCR）检测35例宫颈鳞状细胞癌、15例宫颈上皮内瘤变（CIN）及15例正常宫颈石蜡包埋组织以及Siha和C33a细胞中AT1R mRNA水平。采用免疫组织化学法评估65例宫颈组织切片中AT1R蛋白的表达。并分析AT1R表达与临床病理特征之间的相关性。（2）将Siha和C33a细胞在不同浓度血管紧张素Ⅱ（0、10⁻¹⁰mol/L、10⁻⁹mol/L、10⁻⁸mol/L、10⁻⁷mol/L、10⁻⁶mol/L、10⁻⁵mol/L）作用下培养不同时间后，采用甲基噻唑基四氮唑（MTT）法检测细胞增殖情况。采用酶联免疫吸附测定（ELISA）法检测血管内皮生长因子（VEGF）表达。
（1）在两种宫颈癌细胞系中均检测到AT1R mRNA表达。AT1R mRNA在鳞状细胞癌、宫颈上皮内瘤变和正常宫颈组织中的阳性率分别为77.1%、40.0%和0，其mRNA量分别为0.3863±0.041、0.0768±0.035和0。它们之间差异有统计学意义（P<0.01）。浸润癌细胞中AT1R蛋白的平均染色强度高于发育异常组织和正常组织（P<0.01）。在65例鳞状细胞癌中，AT1R mRNA和蛋白表达随病理分级增加而升高（P<0.05），但与临床分期及盆腔淋巴结转移均无相关性（P>0.05）。AT1R蛋白表达水平与其mRNA水平一致。（2）血管紧张素Ⅱ以剂量依赖方式促进宫颈癌细胞系Siha和C33a的细胞生长并诱导细胞分泌VEGF（P<0.01），加入缬沙坦（血管紧张素Ⅱ1型受体拮抗剂）后VEGF表达逆转（P<0.01）。
血管紧张素Ⅱ参与宫颈癌的进展，因为它可能增加癌细胞的增殖活性，通过AT1R同步诱导VEGF分泌，导致肿瘤血管生成增加。提示使用AT1R拮抗剂可能是宫颈癌的一种有效治疗策略。
