关键词: 食管癌, CDC20, NLRP3, 泛素化, 增殖

Abstract:

Background and purpose: Esophageal carcinoma (ESCA) is one of the malignant tumors with high mortality rate, and the underlying mechanism of its development is largely unknown. CDC20 plays an important role in tumorigenesis, and its dysregulated expression is closely related to tumor occurrence and development. The expression of CDC20 is increased in a variety of tumors, and knocking down CDC20 can inhibit tumor cell proliferation. NLRP3 is the main component of the inflammasome, and inflammasome is also closely related to tumor occurrence and development. Here, our study aimed to investigate whether CDC20 promotes the proliferation of ESCA cells through NLRP3 and its regulatory mechanism. Methods: The expression levels of CDC20 and NLRP3 genes in ESCA patients were analyzed using The Cancer Genome Atlas (TCGA) detabase and GTEx public database. We collected clinical and pathological data and tissues from 80 ESCA patients at the First Affiliated Hospital of Xinxiang Medical College, and detected the protein expression of NLRP3 in ESCA patients through immunohistochemistry staining. This study was approved by the Ethics Committee of the First Affiliated Hospital of Xinxiang Medical College (Number: EC-021-137). We studied the effects of knocking down CDC20 and NLRP3 gene on the proliferation ability of esophageal squamous cell carcinoma cells EC9706 and KYSE150 using short hairpin RNA (shRNA) technology. Co-immunoprecipitation (Co-IP), proteasome inhibitors and ubiquitination experiments were used to detect whether CDC20 interacts with NLRP3, and to elucidate whether CDC20 regulates NLRP3 expression through the ubiquitination pathway. This study was approved by the Ethics Committee of the First Affiliated Hospital of Xinxiang Medical College (Number: EC-021-137). Results: The TCGA database analysis showed that the expression levels of CDC20 and NLRP3 mRNA were significantly higher in the cancer tissues of ESCA patients than in the adjacent tissues. The immunohistochemistry results further showed that compared with adjacent tissues, the protein expression levels of CDC20 and NLRP3 were increased in ESCA tissues. Knocking down CDC20 and NLRP3 genes inhibited the proliferation of ESCA cells. Co-IP, proteasome inhibitors and ubiquitination experiments confirmed that CDC20 interacted with NLRP3 through its leucine-rich repeat (LRR), and CDC20 stabilized its expression by promoting NLRP3 ubiquitination. Conclusion: CDC20 and NLRP3 are upregulated in ESCA tissues, and CDC20 stabilizes their expression through ubiquitination of NLRP3, promoting ESCA cell proliferation. This suggests that CDC20 and NLRP3 may be potential diagnostic targets for ESCA.

Key words: Esophageal carcinoma, CDC20, NLRP3, Ubiquitination, Proliferation