TPPP3, a Good Prognostic Indicator, Suppresses Cell Proliferation and Migration in OSCC.

Introduction And Aims: Oral squamous cell carcinoma (OSCC) is one of the most prevalent malignancy of the head and neck. Early diagnosis of OSCC is difficult and the prognosis has not improved significantly. This study aims to explore the role of tubulin polymerisation promoting protein 3 (TPPP3) in the occurrence and development of OSCC and discover new diagnostic and prognostic markers for OSCC.

Methods: Using UALCAN, GEPIA, western blot, and quantitative real-time polymerase chain reaction, we studied TPPP3 expression and its relationship with tumour stage. Then, we detected the effect of TPPP3 on OSCC biological functions by CCK-8 and cell scratch assays, as well as correlations between TPPP3 expression and survival of different kinds of head and neck squamous cell carcinoma (HNSC) patients through Kaplan-Meier plotter. Besides, we explored coexpressed genes associated with TPPP3 in HNSC using LinkedOmics and protein-protein interaction networks of TPPP3 using STRING and Cytoscape. Furthermore, we explored possible molecular mechanisms that TPPP3 functions in HNSC using UALCAN, Kaplan-Meier plotter, and TIMER. Finally, we analysed promoter methylation level by UALCAN and mutation by cBioPortal of TPPP3 in HNSC.

Results: TPPP3 was less expressed in OSCC. The TPPP3 expression level was negatively correlated with tumour stage. Furthermore, TPPP3 significantly inhibited OSCC proliferation and migration. Besides, TPPP3 high expression was significantly associated with good prognosis in different kinds of HNSC patients. Additionally, TPPP3 may regulate the occurrence and development of OSCC through the PALMD/PI3K pathway. TPPP3 methylation level in HNSC decreased. Finally, we found that TPPP3 genetic alteration was involved in TPPP3 mRNA expression change in HNSC.

Conclusion: TPPP3 functions as a tumour suppressor in OSCC and is associated with good prognosis in HNSC patients. TPPP3 can be used as a potential biomarker for prognosis and diagnosis of OSCC.

Clinical Relevance: TPPP3 can be used as a potential biomarker for prognosis and diagnosis of OSCC in clinical practice.