Background: The efficacy of anti-PD-1 therapy is primarily hindered by the limited T-cell immune response rate and immune evasion capacity of tumor cells. Autophagy-related protein 7 (ATG7) plays an important role in autophagy and it has been linked to cancer. However, the role of ATG7 in the effect of immune checkpoint blockade (ICB) treatment on high microsatellite instability (MSI-H)/mismatch repair deficiency (dMMR) CRC is still poorly understood. Methods: In this study, patients from the cancer genome altas (TCGA) COAD/READ cohorts were used to investigate the biological mechanism driving ATG7 development. Several assays were conducted including the colony formation, cell viability, qRT-PCR, western blot, immunofluorescence, flow cytometry, ELISA, immunohistochemistry staining and in vivo tumorigenicity tests. Results: We found that ATG7 plays a crucial role in MSI-H CRC. Its knockdown decreased tumor growth and caused an infiltration of CD8⁺ T effector cells in vivo. ATG7 inhibition restored surface major histocompatibility complex I (MHC-I) levels, causing improved antigen presentation and anti-tumor T cell response by activating reactive oxygen species (ROS)/NF-κB pathway. Meanwhile, ATG7 inhibition also suppressed cholesterol accumulation and augmentation of anti-tumor immune responses. Combining ATG7 inhibition and statins improved the therapeutic benefit of anti-PD-1 in MSI-H CRC. Importantly, CRC patients with high expression of both ATG7 and recombinant 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) experienced worse prognosis compared to those with low ATG7 and HMGCR expression. Conclusions: Inhibition of ATG7 leads to upregulation of MHC-I expression, augments immune response and suppresses cholesterol accumulation. These findings demonstrate that ATG7 inhibition has therapeutic potential and application of statins can increase the sensitivity to immune checkpoint inhibitors.

Background: Airway epithelium is the first barrier against environmental insults, and epithelial barrier dysfunction caused by cigarette smoke (CS) is particularly relevant to chronic obstructive pulmonary disease (COPD) progression. Our study was to determine whether Azithromycin (AZI) ameliorates CS-induced airway epithelial barrier dysfunction and the underlying mechanisms. Methods: Primary bronchial epithelial cells (PBECs), human bronchial epithelial cells (HBECs), Sprague Dawley rats and nuclear factor erythroid 2-related factor 2 (Nrf2)−/− mice were pretreated with AZI and subsequently exposed to CS. Transepithelial electronic resistance (TEER), junction proteins as well as pro-inflammatory cytokines and apoptosis markers were examined to assess epithelial barrier dysfunction. Metabolomics study was applied to explore the underlying mechanism of AZI. Results: CS-induced TEER decline and intercellular junction destruction, accompanied with inflammatory response and cell apoptosis in PBECs were restored by AZI dose-dependently, which were also observed in CS-exposed rats. Mechanistically, GSH metabolism pathway was identified as the top differentially impacted pathway and AZI treatment upregulated the activities of glutamate cysteine ligase (GCL) and the contents of metabolites in GSH metabolic pathway. Furthermore, AZI apparently reversed CS-induced Nrf2 suppression, and similar effects on airway epithelial barrier dysfunction were also found for Nrf2 agonist tert-butylhydroquinone and vitamin C. Finally, deletion of Nrf2 in both HBECs and C57BL/6N mice aggravated CS-induced GSH metabolism imbalance to disrupt airway epithelial barrier and partially deprived the effects of AZI. Conclusion: These findings suggest that the clinical benefits of AZI for COPD management are related with the protection of CS-induced airway epithelial barrier dysfunction via activating Nrf2/GCL/GSH pathway, providing potential therapeutic strategies for COPD. Graphical

The chemotherapy resistance and toxicity of chemotherapy are major problems in breast cancer treatment. However, candidate biomarkers for predicting clinical outcomes and better prognosis remain lacking. In this study, we analyzed possible impact of 8 genetic variants of fibroblast growth factor receptor1–4 (FGFR1–4) on the treatment response and toxicities in 211 breast cancer patients. DNA was extracted from peripheral blood cells, and the genotypes were examined using the TaqMan Pre-Designed SNP Genotyping Assays. The FGFR4 rs1966265 and FGFR2 rs2981578 contributed to clinical outcome of breast cancer treated with docetaxel–epirubicin-cyclophosphamide (CET)-based chemotherapy. For rs1966265, AA genotype had significant correlation with the clinical response to neoadjuvant chemotherapy (NCT) when compared with GG and AG/GG genotype (P = 0.019 and P = 0.004, respectively). Moreover, A allele of FGFR2 rs2981578 had significant rates of response (P = 0.025). In addition, rs2420946 CC genotype was associated with higher frequency of toxicities compared with TT and CT/TT genotypes (P = 0.038 and P = 0.019, respectively). Also, rs2981578 AG genotype showed higher frequency of toxicities compared with GG genotype (P < 0.0001). The results suggest these polymorphisms, especially rs1966265 and rs2981578, might be candidate pharmacogenomics factors to the response and prognosis prediction for individualized CET-based chemotherapy in breast cancer patients.