TPPP3 Promotes Cell Proliferation, Invasion and Tumor Metastasis via STAT3/ Twist1 Pathway in Non-Small-Cell Lung Carcinoma

Abstract

Background/Aims: Non-small-cell lung carcinoma (NSCLC) is the leading cause of cancer death, with tumor metastasis being mainly responsible for lung cancer-associated mortality. Our previous studies have found that tubulin polymerization promoting protein family member 3 (TPPP3) acted as a potential oncogene in NSCLC. Little is known about the function of TPPP3 in tumor metastasis. Methods: RT-qPCR and IHC were used to investigate the expression of TPPP3 in NSCLC tissues. CCK8 assay and transwell assay were used to measure proliferation and migration of NSCLC cells in vitro and xenograft model was performed to assess the tumor growth and metastasis in vivo. Results: In the present study, upregulation of TPPP3 was found to correlate with an increased metastasis capability of NSCLC. Ectopic expression of TPPP3 significantly enhanced cell proliferation in vitro and promoted tumor growth in vivo. Furthermore, overexpression of TPPP3 remarkably promoted NSCLC cell migration and invasion along with the upregulation of Twist1 both in vitro and in vivo. Further investigations showed that activation of STAT3 was required for TPPP3-mediated upregulation of Twist1, cell migration and invasion. A strong positive correlation between TPPP3 and Twist1 expression was identified in NSCLC tissues. Patients with low TPPP3 or low Twist1 in NSCLC tissues had a better prognosis with longer overall survival (OS) and disease-free survival (DFS). Conclusion: Overall, this study demonstrates that TPPP3 promotes the metastasis of NSCLC through the STAT3/Twist1 pathway.