Phosphoribosyl Pyrophosphate Amido Transferase: A New Prognostic Biomarker for Hepatocellular Carcinoma

BACKGROUND: PPAT (phosphoribosyl pyrophosphate amido transferase) catalyzes the first committed step of de novo purine biosynthesis and is a key regulatory point in the biosynthesis of nascent purine nucleotides. However, the clinical significance and biologic role of PPAT in hepatocellular carcinoma (HCC) remain unknown. METHODS: We compared the expression of PPAT in carcinomatous and precancerous hepatocellular carcinoma tissues by immunohistochemistry in 90 cases of HCC. Correlation analysis was also made on clinical data, survival, classification, and staging. RESULTS: The expression of PPAT in HCC tumor tissues is significantly higher than that in adjacent normal tissues. The results of the Kaplan–Meier analysis showed that HCC patients with high PPAT expression survived shorter than those with low PPAT expression. Moreover, the expression of PPAT was significantly associated with the tumor grade (P=0.014), PD-L1 (P<0.001), and CTLA4 (P=0.003). The later grade of the tumor, the higher the expression of PPAT. In the PD-L1 high expression group, PPAT is also highly expressed. CONCLUSION: Our study demonstrated that PPAT expression might be included in the process of carcinogenesis and prognosis. Hence, PPAT could be served as a new prognostic biomarker for patients of HCC.