Prognostic significance of promyelocytic leukemia expression in gastrointestinal stromal tumor; integrated proteomic and transcriptomic analysis

Prognostic markers are urgently needed to optimize the postoperative treatment strategies for gastrointestinal stromal tumors (GIST). GIST of the small intestine (I‐GIST) show more aggressive behavior than those of the stomach (S‐GIST), and the molecular background of the malignancy in I‐GIST may include potential prognostic biomarkers. We conducted integrated proteomic and transcriptomic analysis to identify genes showing differential expressions according to the tumor site. We generated protein expression profiles for four cases each of surgically resected I‐GIST and S‐GIST using label‐free proteomic analysis. For proteins showing differential expressions, global mRNA expression was compared between 9 I‐GIST and 23 S‐GIST. Among the 2555 genes analyzed, we found that promyelocytic leukemia (PML), a tumor suppressor gene, was significantly downregulated in I‐GIST at both the protein and mRNA levels (P