Downregulation of PDCD10 mitigates the malignant biological behavior and increases the sensitivity of esophageal squamous cell carcinoma cells to radiotherapy by inhibiting the PI3K/AKT pathway.

Abstract

The intensification of radiotherapy is an effective way to improve the therapeutic efficacy of radiation-sensitive malignancies such as esophageal cancer (EC). Esophageal squamous cell carcinoma (ESCC) accounts for 85% of all EC cases worldwide, with a relatively higher incidence and mortality in East Asia. In this study, we explored the functions and mechanisms of programmed cell death 10 (PDCD10) in the malignancy and radiotherapy sensitivity of ESCC cells. We observed that PDCD10 is highly expressed in ESCC tissues and is correlated with a poor prognosis in patients with ESCC. PDCD10 downregulation suppressed ESCC cell proliferation, migration, and invasion but promoted apoptosis. In addition, it enhanced ionizing radiation (IR)-induced ESCC cell damage, whereas PDCD10 overexpression had the opposite effect. Mechanistically, PDCD10 increased the phosphorylation of phosphatidylinositol 3-kinase (PI3K) and protein kinase B (AKT) in ESCC cell lines. The administration of LY294002, a PI3K inhibitor, significantly inhibited the oncogenic functions of PDCD10, leading to an increase in IR-induced cell damage. These findings establish PDCD10 as a critical intrinsic regulator of the sensitivity of ESCC cells to IR through the modulation of the PI3K/AKT pathway.