Hypoxia-Induced TGFBI as a Serum Biomarker for Laboratory Diagnosis and Prognosis in Patients with Pancreatic Ductal Adenocarcinoma

Objective: To explore novel biomarkers for patients with pancreatic ductal adenocarcinoma (PDAC), from the perspective of tumor hypoxia. Methods: We screened 29 differentially expressed and hypoxia-upregulated genes from the Oncomine database. A total of 12 secretory proteins that interact with hypoxia-inducible factor 1 (HIF-1A) were selected by STRING (protein-protein interaction networks). After excluding enzymes and collagens, insulin-like growth factor-binding protein 3 (IGFBP3), glycoprotein NBM (GPNMB), transforming growth factor-beta-induced (TGFBI), and biglycan (BGN) were detected by sandwich enzyme-linked immunosorbent assay (ELISA) in patients with cancer and healthy control individuals. Results: The serum level of TGFBI was significantly elevated in patients with PDAC, compared with healthy controls; the assay could discriminate among cases of PDAC in different clinical stages. The amount of TGFBI was significantly decreased after treatment. The combination of TGFBI and cancer antigen (CA) 19-9 was more accurate than TGFBI or CA 19-9 alone as diagnostic markers. Also, TGFBI might be used as a prognostic marker according to the PROGgeneV2 Pan Cancer Prognostics Database. Conclusions: Serum TGFBI, combined with CA 19-9, offers higher diagnostic value than other methods for patients with PDAC. Also, TGFBI might be used as a prognostic marker.