Hongchao Han,Jie Xu,Weiwei Ji,Lisheng Wang,Aikun Wang
Transmembrane protein with epidermal growth factor (EGF)‑like and two follistatin motifs 2 (TMEFF2) is downregulated in human gastric cancer, and its levels are associated with tumor aggressiveness. Herein, a positive correlation was identified between serum vitamin C levels (µg/ml) and mRNA levels of TMEFF2 in gastric cancer tissue. TMEFF2 silencing promotes cell proliferation in GES‑1 normal human gastric epithelial cells and AGS human gastric adenocarcinoma cells. Notably, vitamin C and AG490 exerted antiproliferative effects on the two cell lines. The present study demonstrated that small interfering (si)‑RNA‑TMEFF2 exerts pro‑proliferative effects on GES‑1 and AGS cells. The results revealed that vitamin C significantly inhibited the growth of GES‑1 and AGS cells by reducing cell viability, decreasing the expression of proliferating cell nuclear antigen (PCNA), and blocking the STAT3 pathway. Moreover, siRNA‑TMEFF2‑induced enhanced cell viability and PCNA expression were significantly reversed by additional vitamin C treatment; notably, markedly enhanced TMEFF2 expression was observed. Upregulated TMEFF2 expression was observed in association with the antiproliferative effect of AG490. In conclusion, serum vitamin C content (µg/ml) was positively correlated with the mRNA levels of TMEFF2 in gastric cancer tissue. Exploring novel drugs that target TMEFF2 is a potential therapeutic strategy for blocking human GC.
Summary Cancer cells tend to utilize aerobic glycolysis to generate energy and metabolites; the end product of aerobic glycolysis is lactate, which promotes lysine lactylation (Kla). Kla is a newly discovered histone post-translational modification (PTM) that plays important roles in regulating gene expression. However, Kla in non-histone mammalian proteins is unclear. Here, a comprehensive analysis of lactylated proteins in gastric cancer AGS cells was conducted. There were 2375 Kla sites found in 1014 proteins. Interestingly, KEGG pathway analysis showed that these proteins were significantly enriched in spliceosome function. In addition, Kla was more abundant in gastric tumors than in adjacent tissues, and high levels of Kla in gastric tumors were associated with poor prognosis. These results suggest that Kla could be a prognostic marker in gastric cancer. This lysine lactylome analysis in gastric cancer cells, the first of its kind, provides a valuable foundation for further studies of Kla.