ITGA3-MET interaction promotes papillary thyroid cancer progression via ERK and PI3K/AKT pathways.

Background: Studies have examined the role of integrin α3 (ITGA3) in papillary thyroid carcinoma (PTC). However, the functional and molecular mechanism by which ITGA3 is involved in the progression of PTC remains poorly understood.

Methods: To investigate the role of ITGA3 in PTC, raw PTC transcriptome data underwent comprehensive bioinformatics analyses, including differential expression, co-expression network, and enrichment analyses. ITGA3 expression was validated via immunohistochemistry and western blotting in PTC tissues. Cell functional assays and xenograft models assessed PTC cell behaviour. The potential mechanisms of ITGA3 were elucidated using bioinformatics analyses, western blotting, co-immunoprecipitation, and immunofluorescence. Finally, integration of ITGA3 expression with clinical parameters enabled nomogram construction for precise prediction of cervical lymph node metastasis (CLNM) in PTC.

Results: ITGA3 was upregulated in PTC and associated strongly with CLNM (79.5% vs. 53.84%, p = 0.016). ITGA3 expression enhanced PTC proliferation and migration in vitro and in vivo via cooperating with the MET protein tyrosine kinase, followed by phosphorylation of MET at Tyr1234/1235, and activation of ERK and PI3K/AKT signaling pathways. Furthermore, upregulation ITGA3 reduced phosphorylation at FAK-Tyr397 and Src-Tyr416 in PTC cells. Finally, a nomogram combining ITGA3 expression and clinical parameters for predicting CLNM was constructed and validated, achieving a ROC curve AUC of 0.719, suggesting potential application for PTC diagnosis.

Conclusions: ITGA3 promotes PTC cell proliferation and migration by cooperating with MET to activate MET-ERK and MET-PI3K-AKT signalling. ITGA3-MET cooperation may serve as a potential therapeutic target.