High expression of Testin predicted worse prognosis in pancreatic adenocarcinoma associated with immune infiltration

Pancreatic adenocarcinoma (PAAD) is a malignant tumor with a very poor prognosis and lacks effective biomarkers. Testin (TES) has an altered expression in a variety of cancers, but its expression and role in PAAD remains elusive.

To explore the prognosis and biological role of TES in PAAD.

In this study, the expression of TES in tumor tissues and the adjacent normal pancreatic tissues of PAAD, and the relationship between TES expression and PAAD overall survival (OS), were determined using gene expression profiling interactive analysis (GEPIA), human protein atlas (HPA) and Ualcan database. The correlation between TES expression and immune infiltration was assessed using tumor immunity estimation resource (TIMER) database. Protein–protein interaction (PPI) network of TES was constructed using the Search Tool for the Retrieval of Interacting Genes (STRING) database. Tissue and blood samples from PAAD or healthy subjects were collected, and the expression of signature genes was analyzed using qRT–PCR.

Our results showed that TES overexpression occurred in PAAD, and predicted worse prognosis. TES expression was positively correlated with the levels of infiltrating B cells, CD8+ T cells, macrophages, neutrophils and dendritic cells. The top six hub genes HSPB1, VASP, RAB2A, ENAH, ZPR1 and THADA that interact with TES were identified, and they all were overexpression in PAAD, but only VASP expression was negatively correlated with PAAD prognosis. In our samples, compared with the adjacent normal tissues, a higher expression of TES and VASP in PAAD tumor tissues was validated.

The present study suggested that TES could function as a supporter and prognostic marker of PAAD, and it might work via inducing immune infiltration.