Ptrh1, short for peptidyl-tRNA hydrolase 1 homolog, is an RNA binding protein (RBP) with significant functions in multiple biological processes. It is involved in the ribosome-associated quality control (RQC) pathway, where it can cleave non-ubiquitinated NC-tRNA in non-ubiquitinated 60S RNCs and 80S RNCs formed on non-stop mRNAs [2]. In addition, it is associated with pathways related to tumor immunity and cell translation processes, making it biologically important in maintaining normal cellular functions and immune responses [1,2].

In pancreatic cancer, high glucose enhances the stability of the PD-L1 mRNA in pancreatic tumor cells by downregulating PTRH1 through RAS signaling pathway activation following epidermal growth factor receptor (EGFR) stimulation. Overexpression of PTRH1 in pancreatic cells significantly suppresses PD-L1 expression and improves the proportion and cytotoxic function of CD8+ T cells in the pancreatic tumor microenvironment (TME) of diabetic mice, indicating its key role in the regulation of PD-L1 by high glucose and its relation to anti-tumor immunity in the pancreatic TME [1].

In conclusion, Ptrh1 is crucial in the RQC pathway for handling interrupted translation and in regulating PD-L1 expression in the context of pancreatic cancer. The findings from the study on pancreatic cancer using diabetic murine models highlight its significance in tumor-associated immune regulation, suggesting that understanding Ptrh1 function may provide insights into new strategies for treating pancreatic cancer and potentially other related diseases [1,2].