Integrative Analysis of Pinin as A Prognostic Factor in Digestive Tract Cancers

Abstract Background: Pinin (PNN) was originally identified for acting an essential role in epithelial cell-cell adhesion. We aim to illuminate the expression profile, mutation feature, methylation status of PNN and its prognostic value in digestive tract cancers. Methods: Expression and methylation data of PNN, as well as clinical information on esophagus cancer (ESCA), gastric adenocarcinoma (STAD), colon adenocarcinoma (COAD) and rectal adenocarcinoma (READ) were acquired from The Cancer Genome Atlas database. The value of PNN expression, mutation feature and methylation status in prognosis were assessed. GO enrichment and Gene set enrichment analysis were performed to investigate the enriched biological functions and pathways of PNN in COAD. Tumor Immune Estimation Resource and CIBERSORT were applied for evaluating the effects of PNN on tumor immune infiltrating cells. Results: PNN was significantly overexpressed in digestive tract cancers and was remarkably related to tumor stage. Highly expressed of PNN was positively related to poor free survival (PFS) and overall survival (OS) in COAD. Additionally, 10 CpG sites methylation in PNN had significant effects on survival. PNN expression was confirmed as an independent prognostic factor for predicting the OS in COAD. GO and GSEA analyses revealed that PNN participates in multiple biological processes underlying carcinogenicity in COAD. PNN was significantly associated with TIICs. Moreover, a promising prognostic nomogram incorporating the PNN expression and clinicopathological characteristics was established for predicting OS probability in COAD. Conclusions: Our comprehensive bioinformatics study demonstrated that PNN was highly expressed in digestive tract cancers, which could act as an independent prognostic factor for COAD.