Objective  To investigate the expression level and clinical significance of ALDH5A1 in ovarian cancer (OC) tissues, as well as to explore the possible mechanism associated with the invasion and migration of OC cells.

Methods  We initially compared ALDH5A1 expression in metastatic tissues and the primary site of OC based on the GEO database. Then, wound-healing and Transwell assays were utilized to determine the biological role of OC cells transfected with ALDH5A1 siRNA. To unravel the potential mechanism of ALDH5A1 meditating the metastasis of OC, the coexpression profile of ALDH5A1 in OC cell lines and OC patients were generated using cBioPortal. Moreover, the TCGA and GEO databases were used to analyze the relationship between ALDH5A1 expression and the prognosis of OC patients. The HPA database was further used to confirm the relative expression of ALDH5A1 and MMPs in OC patients.

Results  ALDH5A1 expression was downregulated in metastatic tissues compared with the primary site of OC, and ALDH5A1 knockdown promoted the malignant behavior of OC cells. Additionally, the coexpression profile of ALDH5A1 was significantly enriched in the extracellular matrix (ECM) organization pathway. Western blot assay further confirmed that the expression of MMP, which played an important role in the ECM pathway, was negatively correlated with ALDH5A1 expression in OC. These results indicated that ALDH5A1 may participate in the metastasis and invasion of OC via the ECM organization pathway. Finally, KM survival plots revealed that the survival rates of OC patients with lower ALDH5A1 expression were obviously lower.

Conclusion  ALDH5A1 downregulation may promote the tumor metastasis and contribute to poor prognosis in OC.