Silencing PPAP2C inhibits lung adenocarcinoma migration and invasion via the ERK/JNK pathway.

Abstract

Lung adenocarcinoma (LUAD) is a leading cause of cancer‑related death due to its aggressive nature and metastatic potential. The present study aimed to explore the expression of phospholipid phosphatase 2 (PPAP2C) in LUAD, and its effect on cell migration and invasion, with a particular focus on its association with the ERK/JNK signaling pathway and epithelial‑mesenchymal transition (EMT). The expression of PPAP2C in LUAD was analyzed using data from The Cancer Genome Atlas database. Pearson's correlation coefficient analysis was used to assess the correlation between PPAP2C and genes such as MAPK1, MAPK3, MAPK8, CDH1, CDH2 and SNAI1. Subsequently, the PPAP2C gene was silenced in A549 and H1299 LUAD cell lines using siRNA vectors, followed by assessments of gene expression, cell migration, invasion and protein interaction using reverse transcription‑quantitative PCR, western blotting, wound healing assay, Transwell invasion assay, molecular docking analysis, co‑immunoprecipitation and immunofluorescence staining. The results showed that PPAP2C was significantly upregulated in LUAD tissues compared with that in normal tissues. In addition, high levels of PPAP2C were significantly correlated with MAPK3, MAPK8, CDH1 and SNAI1. Notably, PPAP2C silencing significantly inhibited cell migration and invasion. Additionally, it reduced the phosphorylation levels of ERK and JNK proteins. PPAP2C showed specific binding sites with ERK1, and co‑precipitated with ERK1 in both A549 and H1299 cells. Furthermore, PPAP2C silencing decreased the expression levels of N‑cadherin and Snail, while increasing E‑cadherin expression, thereby inhibiting EMT. In conclusion, PPAP2C may be highly expressed in LUAD tissues, and could promote cell migration and invasion by activating the ERK/JNK signaling pathway and inducing EMT. These findings provide a novel potential target for the diagnosis and treatment of LUAD.