Autophagy, a process for degrading intracellular substances to maintain basal metabolic turnover, is known to be perturbed in gastric cancer. Programmed cell death-1 (PD-1) with its ligand (PD-L1) are important immune checkpoint proteins and their regulation by autophagy has been reported in mouse melanoma and human ovarian cancer. Here, we explored the interplay between autophagy and the PD1/PD-L1 axis in gastric cancer. The expression of PD-L1 in gastric cancer cells was detected by Western blot and flow cytometry analysis. The effect of autophagy inhibition on PD-L1 expression was examined in vitro and in vivo. The molecular mechanisms of the regulation of PD-L1 by autophagy were evaluated in gastric cancer cell lines. The clinical relevance of autophagy-related markers p62/SQSTM1 and LC3 with PD-L1 was evaluated in 137 patients with gastric cancer. We found that inhibition of autophagy by pharmacological inhibitors or small interfering RNAs increased the levels of PD-L1 in cultured gastric cancer cells and in xenografts. Interferon (IFN)-γ also promoted PD-L1 gene transcription, whose action was enhanced by autophagy inhibition. Mechanistically, autophagy inhibition led to the accumulation of p62/SQSTM1 and activation of nuclear factor (NF)-κB, in which NF-κB inhibition or p62/SQSTM1 knockdown attenuated PD-L1 induction by autophagy inhibition. Immunohistochemical staining of primary tumor tissues of 137 patients with gastric cancer showed that LC3 and p62/SQSTM1 protein levels were positively correlated with PD-L1 (LC3, p < 0.001; p62/SQSTM1, p < 0.05). The expression of PD-L1 was also positively correlated with tumor lymphocyte infiltration (p < 0.001). We discovered that autophagy regulates PD-L1 expression in gastric cancer through the p62/SQSTM1-NF-κB pathway. Pharmacological modulation of autophagy may thus influence the therapeutic efficacy of PD-L1 blockade in gastric cancer.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide. Liver transplantation (LT) remains a vital treatment for HCC, yet it still faces numerous challenges in patient selection, recurrence monitoring, and personalized therapy. Third-generation sequencing (TGS), with its advantages of long read length, high throughput, direct detection of epigenetic modifications, real-time analysis and high accuracy, offers promise for advancing precision medicine in LT. While previous reviews have focused on TGS technical features, this review uniquely synthesizes its role in addressing specific clinical challenges in LT-HCC management and critically assesses its translational pathway. Specifically, it systematically examines TGS applications in candidate screening, recurrence monitoring, and personalized therapy for LT-HCC, analyzes its prospects for clinical translation, and aims to provide new insights for precise HCC treatment. We also discuss barriers to implementation and suggest solutions for integrating TGS into clinical workflows. This review provides a roadmap for leveraging TGS to revolutionize precision medicine in transplant hepatology.