在多种恶性肿瘤中，环状RNA（circRNA）被认为发挥着至关重要的作用。我们之前的结果表明，circ_ZNF778_006在食管鳞状细胞癌（ESCC）组织中显着增加，但circ_ZNF778_006在ESCC中的作用仍不清楚。比较circ_ZNF778_006在食管鳞癌不同病理级别中的表达情况。并分别通过qRT-PCR和Western blot分析circ_ZNF778_006、miR-18b-5p、HIF-1α的表达水平。应用质粒转染技术制备具有沉默或过表达基因（CircZNF778_006、miR-18b-5p）的ESCC细胞。采用CCK8试剂盒测定细胞增殖情况，采用Transwell实验测定细胞迁移和侵袭能力。在体内研究了 circ_ZNF778_006 对肿瘤生长的影响。此外，进行荧光素酶报告基因测定和RNA结合蛋白免疫沉淀（RIP）以验证miR-18b-5p与circZNF778_006、miR-18b-5p与HIF-1α之间的靶向关系。 circ_ZNF778_006在ESCC中的表达与病理分级呈正相关。 Circ_ZNF778_006 显着抑制对 5-氟尿嘧啶的敏感性

In multiple malignant tumors, circular RNAs (circRNAs) are believed to play a crucial role. Our prior results demonstrated that circ_ZNF778_006 was significantly increased in esophageal squamous cell carcinoma (ESCC) tissues, but the roles of circ_ZNF778_006 in ESCC is still not clear. The expression of circ_ZNF778_006 was compared in different pathological grades of ESCC. And the expression levels of circ_ZNF778_006, miR-18b-5p, HIF-1α were analyzed by qRT-PCR and Western blot, respectively. Plasmid transfection techniques were applied to prepare ESCC cells with silenced or overexpressed genes (CircZNF778_006, miR-18b-5p). The CCK8 kit was used to determine cell proliferation, and the Transwell assay was used to measure the migration and invasion. The effects of circ_ZNF778_006 on tumor growth was investigated in vivo. Furthermore, luciferase reporter gene assay and RNA-binding protein immunoprecipitation (RIP) were performed to verify the targeting relationship between miR-18b-5p and circZNF778_006, miR-18b-5p and HIF-1α. The expression of circ_ZNF778_006 was positively correlated with pathological grade in ESCC. Circ_ZNF778_006 significantly inhibited sensitivity to 5-fluorouracil & cisplatin. It could promote the proliferation, invasion, migration in ESCC cells and accelerated tumor growth in vivo. Furthermore, circ_ZNF778_006 could upregulate the expression of HIF-1α via sponing miR-18b-5p. Circ_ZNF778_006 promoted ESCC progression by upregulating HIF-1α expression via sponging miR-18b-5p.© 2023. The Author(s).