Het 1a cell line

Human normal esophageal epithelial Het-1A cell line and human ESCC cell lines (ECA-109 and KYSE450) were obtained from American Type Culture Collection (ATCC, Manassas, VA, USA). The luciferase-labeled ECA-109-luc and KYSE450-luc cells were obtained from Shanghai Chenyishiye Co., Ltd (Shanghai, China). The above cells were cultivated in Dulbecco’s modified Eagle’s medium (DMEM) (MD207-050, Gibco-BRL/Invitrogen, Waltham, MA, USA) supplemented with 10% fetal bovine serum (FBS; 16000-044, Gibco, USA) and 100× penicillin/streptomycin solution (15140122, Gibco-BRL/Invitrogen, USA). Human embryonic lung fibroblast HFL1 cell line was obtained from BeNa Culture Collection (China) and cultured with 90% F-12K plus 10% FBS.

Human esophageal epithelial cell line (Het-1A) and ESCC cell lines (TE-1, KYSE-30, EC109 and EC9706) were used in the present study. Het-1A cell line was obtained from the American Type Culture Collection (Manassas, VA, United States) and TE-1 cell line was purchased from Chinese Academy of Medical Sciences (Beijing, China). In addition, KYSE-30 and EC109 cell lines were derived from CoBioer (Nanjing, China) and EC9706 cell line was gotten from Shanghai Huiying (Shanghai, China). KYSE-30 or EC109 cells were transfected with the small interfering RNA (siRNA) targeting lnc-MCEI (si-MCEI), miR-6759-5p mimics, miR-6759-5p inhibitor at 50 % confluence. Lnc-MCEI and negative control (NC) hairpin RNA (shRNA) sequences were purchased from GenePharma (Shanghai, China) and cloned into the pBS/U6 vector (Addgene) for lnc-MCEI knockdown. Additionally, the IGF2 expression plasmids construction and transient transfection were performed as the protocol previously described 19 .