摘要目的:探讨高级别卵巢浆液性癌（HGSOC）组织中内皮素A受体（ETAR）表达的临床意义；设计ETAR羧基末端（ETAR-C）氨基酸序列来源的ETAR-C融合多肽，研究其对卵巢上皮性癌（卵巢癌）细胞的体外抑癌作用。方法:（1）选择2007年1月1日至2017年12月31日在徐州市中心医院接受手术治疗、术后病理检查确诊为HGSOC且有完整临床病理资料及随访资料的患者共126例，收集其癌组织标本，采用逆转录-PCR技术检测HGSOC组织中ETAR mRNA的表达，并分析其临床意义。（2）以ETAR-C氨基酸序列为基础设计ETAR-C融合多肽，通过体外表达、纯化ETAR-C融合多肽，采用划痕实验、侵袭实验分别检测ETAR-C融合多肽处理后卵巢癌SKOV3和CAOV3细胞的迁移、侵袭能力，四甲基偶氮唑蓝（MTT）比色法检测ETAR-C融合多肽处理后顺铂耐药卵巢癌SKOV3/cDDP和CAOV3/cDDP细胞的化疗敏感性，蛋白印迹（western blot）法检测ETAR-C融合多肽处理后卵巢癌SKOV3和CAOV3细胞中β抑制蛋白1（β-arrestin-1）的表达。结果:（1）HGSOC组织中ETAR mRNA的相对表达水平为18.6±5.1，X-Tile软件分析显示最佳截断值为61.7%，据此将HGSOC患者分为ETAR mRNA高表达（76例）和低表达（50例）。ETAR mRNA高表达与HGSOC患者的腹水量、铂类药物耐药和血清癌抗原125（CA 125）水平均显著有关（ P均<0.05），而与HGSOC患者的年龄、术后残留灶大小无关（ P均>0.05）；ETAR mRNA高表达和低表达患者的5年无进展生存率分别为18.4%、28.0%，5年总生存率分别为38.2%、52.0%，两者分别比较，差异均有统计学意义（ P=0.046， P=0.034）。（2）划痕实验和侵袭实验结果均显示，内皮素1（ET-1）、ET-1+ETAR-C分别处理后SKOV3和CAOV3细胞的划痕愈合率和细胞侵袭率分别比较，差异均有统计学意义（ P均<0.05）。MTT比色法检测显示，加入不同浓度（4、6、8、10、12、24 μg/ml）顺铂后，ETAR-C融合多肽处理后的SKOV3/cDDP和CAOV3/cDDP细胞的抑制率均显著高于对照细胞（ P均<0.05）。western blot法检测显示，ET-1、ET-1+ETAR-C分别处理后SKOV3细胞（分别为1.85±0.09、1.13±0.09）和CAOV3细胞（2.14±0.15、1.66±0.12）中β-arrestin-1蛋白的表达水平分别比较，差异均有统计学意义（ P均<0.05）。 结论:ETAR mRNA高表达HGSOC患者的预后显著差于ETAR mRNA低表达者，ETAR可能成为HGSOC治疗的新靶点。干扰ETAR与β-arrestin-1相互作用的ETAR-C融合多肽具有良好的体外抑制卵巢癌细胞的效果，具有临床应用潜力。

abstractsObjective:To investigate the clinical significance of endothelin A receptor (ETAR) expression in high-grade serous ovarian carcinoma (HGSOC). To design ETAR carboxyl terminal (ETAR-C) amino acids derived polypeptide and to study the inhibitory effect on ovarian epithelial carcinoma cells in vitro.Methods:(1) A total of 126 patients who received surgical treatment and were diagnosed with HGSOC by postoperative pathological examination in Central Hospital of Xuzhou from January 1, 2007 to December 31, 2017 were selected. All patients had completed clinicopathological data and follow-up data. Cancer tissue samples were collected and ETAR mRNA expression in HGSOC tissues was detected by reverse transcript-PCR. The clinical significance was analyzed. (2) ETAR-C fusion polypeptide was designed based on the sequence of carboxyl terminal amino acids of ETAR, expressed and purified in vitro. The effects of ETAR-C fusion polypeptide on migration and invasion ability of ovarian cancer SKOV3 and CAOV3 cells were detected by scratch test and invasion test, respectively. The effect of ETAR-C fusion polypeptide on chemosensitivity of cisplatin-resistant ovarian cancer SKOV3/cDDP and CAOV3/cDDP cells was determined by methyl thiazolyl tetrazolium (MTT) colorimetric assay. The effect of ETAR-C fusion polypeptide on β-arrestin-1 expression in ovarian cancer SKOV3 and CAOV3 cells was detected by western blot.Results:(1) The relative expression level of ETAR mRNA in HGSOC tissues was 18.6±5.1. Patients with HGSOC were divided into high ETAR mRNA expression ( n=76) and low ETAR mRNA expression ( n=50) with 61.7% as cut-off value analyzed by X-Tile software. High expression of ETAR mRNA was significantly correlated with abdominal water volume, platinum drug resistance, and cancer antigen 125 (CA 125) value in HGSOC patients (all P<0.05), but was not related to the age of patients with HGSOC and the size of postoperative residual lesions (all P>0.05). The 5-year progression free survival rates were 18.4% and 28.0%, and the 5-year overall survival rates were 38.2% and 52.0% in HGSOC patients with high and low ETAR mRNA expression respectively, there were statistically significant differences ( P=0.046, P=0.034). (2) The results of scratch test and invasion test showed that the scratch healing rate and cell invasion rate of SKOV3 or CAOV3 cells treated with endothelin-1 (ET-1) and ET-1+ETAR-C were respectively compared, and the differences were statistically significant (all P<0.05). MTT assay showed that the inhibition rates of ETAR-C fusion polypeptide treated in SKOV3/cDDP and CAOV3/cDDP cells were significantly higher than those of control cells after the addition of 4, 6, 8, 10, 12, and 24 μg/ml cisplatin (all P<0.05). Western blot analysis showed that the relative expression levels of β-arrestin-1 in SKOV3 or CAOV3 cells treated with ET-1 and ET-1+ETAR-C were 1.85±0.09 and 1.13±0.09 (SKOV3 cells), 2.14±0.15 and 1.66±0.12 (CAOV3 cells), respectively. The differences were statistically significant (all P<0.05). Conclusions:The prognosis of HGSOC patients with high expression of ETAR mRNA is significantly worse than those with low expression of ETAR mRNA. ETAR might be a new target for HGSOC treatment. The ETAR-C fusion polypeptide that interferes with the interaction of ETAR and β-arrestin-1 has good inhibitory effect on ovarian cancer cells in vitro, and might have clinical application potential.