title: Casticin inhibits the activity of transcription factor Sp1 and the methylation ofRECKin MGC803 gastric cancer cells.
abstract: The present study investigated the effect of casticin on reversion-inducing-cysteine-rich protein with kazal motifs (RECK) gene expression and intracellular methylation levels in MGC803 gastric cancer cells. Cells were treated with 1, 10 and 30 µmol/l casticin. Western blotting and reverse transcription-quantitative polymerase chain reaction assays were performed to determine the protein expression and mRNA levels of RECK and DNA methyltransferase 1 (DNMT1), respectively. High-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry was used to detectRECKmethylation. In addition, MGC803 cell proliferation was measured by an MTT assay and the DNA-binding activity of transcription factor Sp1 was determined using an enzyme-linked immunosorbent assay. The results demonstrated that treatment with 1, 10 and 30 µmol/l casticin significantly increased RECK protein expression and mRNA levels. In addition, casticin (30 µmol/l) decreasedRECKpromoter methylation levels by 31%, global DNA methylation levels by 39% and nuclear methylation activity by 71.6%. Furthermore, casticin downregulated the mRNA levels and protein expression of DNMT1. The MTT assay demonstrated that MGC803 cell proliferation was inhibited by casticin treatment and DNA binding assays indicated that casticin reduced the DNA-binding activity of Sp1. The present study therefore indicated that casticin inhibits the proliferation of gastric cancer MGC803 cells by upregulatingRECKgene expression and reducing intracellular methylation levels.
authors.affiliation: Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510280, P.R. China; Department of Basic Medicine, Xiangnan University, Chenzhou, Hunan 423000, P.R. China.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.affiliation: Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510280, P.R. China.
authors.forename: Kefei
authors.initials: K
authors.lastname: He
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, Jiangxi 341000, P.R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Huang
authors.affiliation: Medical Department of Chongqing Bishan People's Hospital, Chongqing 402760, P.R. China.
authors.forename: Lingyan
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Oncology, The Second People's Hospital of Shenzhen, Shenzhen, Guangdong 518000, P.R. China.
authors.forename: Aixue
authors.initials: A
authors.lastname: Liu
authors.affiliation: Department of Oncology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong 510280, P.R. China.
authors.forename: Jiren
authors.initials: J
authors.lastname: Zhang
keywords: casticin; gastric cancer; methylation; reversion-inducing-cysteine-rich protein with kazal motifs; transcription factor Sp1