Abstract
13‑Chlorine‑3,15‑dioxy‑gibberellic acid methyl ester (GA‑13315), a gibberellin derivative, possesses strong anti‑tumor activity in vitro and in vivo. The present study aimed to investigate the underlying mechanisms of GA‑13315‑induced apoptosis in human non‑small cell lung cancer cell lines. Lung cancer cells were treated with different doses of GA‑13315 (4, 8, 16 and 32 ng/µl) for 48 h, and a CCK8 assay was performed to measure cell viability. Alteration in gene expression was identified using RNA‑sequencing (RNA‑Seq). Quantitative polymerase chain reaction (qPCR) was used to confirm the differentially expressed genes (DEGs) identified in RNA‑Seq. Gene expression plasmids or small interfering RNA were used to overexpress or silence targeted genes, in order to investigate downstream signals. Chromatin immunoprecipitation was conducted to evaluate the binding of transcription factors to the target genes. A Student's t‑test or one‑way analysis of variance followed by Tukey's honestly significant difference post‑hoc test were performed to evaluate the significance between groups. P<0.05 was considered to indicate a statistically significant difference. GA‑13315 significantly decreased the number of viable cells and induced apoptosis among lung cancer cells (median lethal dose =12‑16 ng/µl). RNA‑Seq identified 250 significant DEGs, including 94 upregulated and 156 downregulated genes in A549 cells (P<0.05; fold change ≥1.5). Upregulation of TRIM67, NF‑κB subunit 2 (NF‑κB2) and FAS was additionally confirmed using qPCR and western blot analysis in A549 and H460 cells. Apoptosis of A549 cells was significantly decreased following knockdown of TRIM67. GA‑13315 promoted TRIM67 expression to increase FAS expression and cell apoptosis. TRIM67 promoted the processing of NF‑κB2 into its active form, p52, which then enhanced the NF‑κB pathway and GA‑13315‑induced apoptosis.