CREB1 Regulates RECQL4 to Inhibit Mitophagy and Promote Esophageal Cancer Metastasis

Abstract

Background: Mitophagy is a cellular survival mechanism that is indispensable in carcinogenesis and tumor progression. However, the research on the mechanism of mitophagy in esophageal cancer metastasis is limited. This study explored the regulatory mechanism by which RECQL4 regulates mitophagy and affects esophageal cancer metastasis.

Methods: The RECQL4 expression in esophageal cancer tissues was examined by bioinformatics analysis and validated by qRT-PCR. Bioinformatics analysis was used to determine the upstream regulatory factor of RECQL4, CREB1, and find the correlation between them. Their binding relationship was evaluated using dual luciferase assay and Chromatin Immunoprecipitation (ChIP) assay. The role of RECQL4 in the viability and metastasis of esophageal cancer cells was investigated through experiments including CCK-8, Transwell, and immunofluorescence. GFP-LC3 plasmid was transfected into cells, followed by western blot (WB) to detect the expression of autophagy marker proteins LC3Ⅰ, LC3Ⅱ, and p62 to analyze mitophagy.

Results: The expression of RECQL4 was up-regulated in esophageal cancer tissues and cells. Overexpression of RECQL4 promoted the viability, invasion, migration, and epithelial-mesenchymal transition (EMT) of esophageal cancer cells by inhibiting mitophagy. Bioinformatics analysis found a substantial positive correlation between the expression of RECQL4 and its upstream transcription factor, CREB1, followed by validation of their binding relationship using dual luciferase and ChIP assays. CREB1 knockdown promoted mitophagy and prevented the metastasis of cancer cells, which could be countered by overexpressing RECQL4.

Conclusion: In this study, CREB1 was found to transcriptionally activate RECQL4 to inhibit mitophagy, thereby promoting esophageal cancer metastasis. This suggests that targeting mitophagy could be an effective therapeutic approach for esophageal cancer.