The Nod-like receptor (NLR) family CARD domain containing 5 (NLRC5) has been reported as an activator of human leukocyte antigen (HLA) class I that is responsible for immune activity in cancer treatment. This work focuses on the role of BMI1 proto-oncogene (BMI1) in the NLRC5-HLA class I axis and in immune escape in nonsmall cell lung cancer (NSCLC). First, immunoblot analysis and/or reverse transcription-quantitative polymerase chain reaction were performed, which identified decreased NLRC5 and HLA class I levels in NSCLC tissues and cell lines. NSCLCs were co-cultured with activated CD8 + T cells. Overexpression of NLRC5 in NSCLC cells elevated the expression of HLA class I and increased the activity of T cells and IL-2 production, and it reduced the PD-1/PD-L1 levels. The ubiquitination and immunoprecipitation assays confirmed that BMI1 bound to NLRC5 to induce is ubiquitination and protein degradation. Downregulation of BMI1 in NSCLC cells elevated NLRC5 and HLA class I levels, and consequently promoted T cell activation and decreased PD-1/PD-L1 levels in the co-culture system. However, overexpression of BMI1 in cells led to inverse trends. In summary, this study demonstrates that BMI1 induces ubiquitination and protein degradation of NLRC5 and suppresses HLA class I expression, which potentially helps immune escape in NSCLC.

BackgroundDespite the fact that numerous clinical and preclinical studies have demonstrated the synergistic effects of combining antiangiogenic or chemotherapy with immunotherapy, no data have been found to indicate that combination therapy is more effective and safer as second-line therapy.MethodsWe retrospectively compared the effectiveness and safety of ICIs plus rh-endostatin to ICIs plus chemotherapy in patients with advanced non-small cell lung cancer (NSCLC). The evaluation indicators of this study were progression-free survival (PFS), safety profile, objective response rate (ORR), disease control rate (DCR), and 1-year overall survival (OS).ResultsThe median PFS with immunotherapy plus rh-endostatin (IE) was 7.10 months (95% CI, 4.64 to 9.56) versus 5.13 months (95% CI, 4.29 to 5.97) with immunotherapy plus chemotherapy (IC) (HR, 0.56; 95%CI, 0.33 to 0.95). Treatment-related adverse events of grade 3 or 4 occurred in 7.5% of the IE group versus 25.0% of the IC group. The ORR in the IE group was 35.0% versus 20.8% in the IC group (P = 0.137), and the DCR in the IE group was 92.5% versus 77.1% in the IC group (P = 0.049). The 1-year OS rate for the IE group was 69.4%, which was higher than the 61.4% of the IC group.ConclusionOur study showed that ICI therapy combined with endostatin therapy exhibits high efficacy and safety, suggesting that such a combination might be a viable treatment option for patients with pre-treated NSCLC in the future.

Background: To assess the efficacy and safety of combination of PD-1 inhibitors, recombinant human endostatin (Rh-endostatin) and chemotherapy as first-line treatment for advanced non-small-cell lung cancer (NSCLC). Methods: A total of 100 patients with advanced NSCLC were retrospectively reviewed and analyzed (58 in the group receiving PD-1 inhibitors plus Rh-endostatin and chemotherapy; 42 in the group receiving Rh-endostatin and chemotherapy). The primary end point was progression-free survival. Results: Patients in the group receiving PD-1 inhibitors plus Rh-endostatin and chemotherapy had significantly improved progression-free survival (10.2 vs 6.5 months; p < 0.001) and objective response rate (67.2 vs 42.9%; p = 0.015), with acceptable toxicity. Conclusion: Our study showed the superiority of combination therapy of PD-1 inhibitors and Rh-endostatin as first-line treatment for advanced NSCLC.