NCAPD2 promotes the progression of lung adenocarcinoma through an AKT/MDM2/E2F1 positive feedback loop.

INTRODUCTION: Lung adenocarcinoma (LUAD) is one of the leading causes of cancer-related deaths worldwide. While NCAPD2 has been implicated in promoting tumorigenesis across various cancer types, its specific role in LUAD remains underexplored. This study aims to elucidate the molecular mechanisms by which NCAPD2 contributes to LUAD progression, with a focus on its involvement in the AKTMDM2/E2F1 positive feedback loop. MATERIALS AND METHODS: NCAPD2 expression in LUAD and normal tissues was analyzed using Western blotting and immunohistochemistry (IHC). Functional assays, including colony formation, wound healing, Transwell assays, and in vivo mouse models were conducted to evaluate the impact of NCAPD2 on LUAD cell proliferation, invasion, and metastasis. RNA sequencing and protein interaction experiments were used to investigate the role of NCAPD2 in the PI3K/AKT/MDM2 pathway and its interaction with E2F1. RESULTS: This study first identified that NCAPD2 expression is significantly upregulated in LUAD tissues, particularly in higher pathological stages. NCAPD2 overexpression promoted LUAD cell proliferation and metastasis, while its knockdown inhibited tumor growth and invasion. Mechanistically, NCAPD2 activated the PI3K/Akt pathway, facilitating the interaction between MDM2 and E2F1, reducing E2F1 ubiquitination, and increasing its expression. Furthermore, E2F1 enhanced NCAPD2 transcription, forming a positive feedback loop that drives LUAD progression. CONCLUSION: This study reveals a novel role of NCAPD2 in promoting LUAD progression through the AKT/MDM2/E2F1 positive feedback loop. These findings provide new insights into the molecular pathogenesis of LUAD and suggest NCAPD2 as a potential therapeutic target for improving patient outcomes.