U2AF2-regulated alternative splicing of UPP1 promotes NSCLC progression by enhancing glycolysis

U2 small nuclear RNA auxiliary factor 2 (U2AF2), a key pre‑mRNA splicing factor whose role in NSCLC progression remains incompletely understood, was previously found by us to be significantly upregulated in non‑small cell lung cancer (NSCLC) tissues and to contribute to NSCLC progression‑related phenotypes. In this study, we observed that knockdown of U2AF2 induced exon 4-6 skipping in UPP1. Consistent with the role of U2AF2 in metabolic regulation, UPP1 was also found to modulate glycolysis‑related metabolic activity, with the UPP1‑L isoform exerting a more pronounced enhancement of glycolytic parameters, particularly under high glucose conditions. In vitro and in vivo functional assays showed that knockdown of UPP1‑L more strongly inhibited lung cancer cell growth and more robustly increased caspase‑dependent apoptosis than either control or UPP1‑S knockdown; Similarly, UPP1‑L knockdown caused a greater reduction in cancer cell migration and invasion and more clearly attenuated EMT‑associated phenotypes compared with UPP1‑S knockdown. Co‑IP assays indicated that UPP1‑L and UPP1‑S interact with partially distinct sets of proteins, which may at least partially underlie their differential functional effects in lung cancer cells. Analysis of clinical NSCLC samples further revealed a significant positive correlation between U2AF2 and UPP1‑L expression levels and showed that elevated UPP1‑L expression was significantly associated with poorer prognosis. Collectively, these findings identify a previously unrecognized role of U2AF2 in regulating UPP1 alternative splicing during NSCLC progression and suggest that modulation of UPP1 splicing may represent a potential therapeutic vulnerability in NSCLC.