Identification of lysine acetylome of oral squamous cell carcinoma by label-free quantitative proteomics

Lysine acetylation (Kac) on histone promotes relaxation of the chromatin conformation and favors gene transcription to regulate oncogenesis, whereas the total acetylation profiling of oral squamous cell carcinoma (OSCC) is unknown. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was utilised to investigate lysine acetylation features of tumor tissues and adjacent normal tissues from 9 patients with OCSS. 282 upregulated Kac sites in 234 proteins and 235 downregulated Kac sites in 162 proteins between OSCC tissues and paired adjacent normal tissues were identified. Different acetylation proteins (DAPs) were analyzed through KEGG-based and MCODE. These DAPs are enriched in the ribosome biogenesis pathway. Survival Analysis of hub genes with TCGA database was performed. In addition, IPA software was used to explore the connection between 9 core DAPs (RPS3, RPL24, RPL19, EIF4A2, RPL12, MYBPC1, RPS6, ARCN1, and TMEM9) and the different expression of KATs and KDACs identified in our proteomic. The study is the first comparative study of Kac modification on oral squamous cell carcinoma. We propose to put forward the hypothesis that the dysfunction of ribosome biogenesis caused by the change of Lysine acetylation, especially downregulated acetylation on RPS6 and RPS3 may associated with the pathogenesis of OSCC. SIGNIFICANCE: The study is the first comparative study of Kac modification on oral squamous cell carcinoma through LC-MS/MS-based modified proteomic. These DAPs are high enriched in the ribosome biogenesis pathway. Used MCODE and survival analysis, 9 core DAPs (RPS3, RPL24, RPL19, EIF4A2, RPL12, MYBPC1, RPS6, ARCN1, and TMEM9) were screened. IPA software was used to explore the connection between 9 core DAPs and the different expression of KATs and KDACs identified in our proteomic. In addition, we propose to put forward the hypothesis that the dysfunction of ribosome biogenesis caused by the change of Lysine acetylation, especially downregulated acetylation on RPS6 and RPS3 may associated with the pathogenesis of OSCC.