Knockdown NEK7 stimulates anti-tumor immune responses by NLRP3/PD-L1 signaling in esophageal cancer.

Abstract

Background: Esophageal cancer is a prevalent malignancy with limited treatment options. The study aimed to understand the role and mechanism of NEK7 in esophageal cancer development.

Methods: RNA sequencing compared esophageal cancer tissues with adjacent tissues, and real-time PCR validated NEK7 expression. Co-IP identified NLRP3 as NEK7's binding partner. We also study the effects of NEK7 knockdown on cell viability, apoptosis, migration, invasion, and the expression of NLRP3/PD-L1 in esophageal carcinoma cell lines. TIMER 2.0 analyzed immune infiltration. An animal model was used to investigate the impact of NEK7 knockdown on tumor size, survival rates, and immune cell infiltration. Licochalcone B blocked NEK7/NLRP3, enhancing CD8 T cell-mediated tumor killing. PD-1's role in T cell viability was also assessed.

Results: NEK7 was observed to be markedly elevated in both tumor tissues of esophageal cancer and EC109 cells. Moreover, silencing NEK7 reduced cell viability, migration, and invasion, while enhancing cell apoptosis in vitro. Knockdown of NEK7 caused a notable reduction in levels of NLRP3 and PD-L1 in EC109 cells. NEK7 expression showed a positive correlation with immune cell infiltration. Knockdown of NEK7 decreased PD-L1 expression, while upregulation of NEK7 increased PD-L1 expression, then reversed by NLRP3 knockdown. In animal studies, NEK7 knockdown reduced tumor size and volume while improving survival. It also promoted CD4 and CD8 T cell infiltration while inhibiting Treg cells and PD-1 + CD4 and CD8 T cells. Licochalcone B blocked NEK7/NLRP3 binding, decreased cell viability of EC109 cells, and enhanced the activity of co-cultured CD8 T cells. Furthermore, Licochalcone B and anti-PD-1 treatment increased the killing ratio of EC109 cells.

Conclusion: In conclusion, NEK7 is a key regulator in the progression of esophageal cancer and the immune evasion. Targeting the NEK7/NLRP3 pathway may have therapeutic potential for the treatment of esophageal cancer.