The role of LncRNA-MANCR induced by HIF-1α drive the malignant progression of pancreatic cancer by targeting miRNA-494/SIRT1 signaling axis under hypoxic conditions.

Abstract

This study revealed the prospective biological role and fundamental mechanisms of hypoxia-induced lncRNA-MANCR (MANCR), which is notably upregulated in pancreatic cancer (PC). This work uncovered the potential biological function and underlying mechanisms of hypoxia-induced MANCR, which is significantly elevated in PC. Microarray assays confirmed MANCR expression in the tissues of patients with PC and patients with chronic pancreatitis (CP), which positively correlated with sirtuin-1 (SIRT1) mRNA levels. Chromatin immunoprecipitation and luciferase assays were employed to gauge binding within the hypoxia-inducible factor-1α (HIF-1α)/MANCR/miRNA-494/SIRT1 pathway. Additionally, the association between MANCR expression and the clinical outcomes of patients with PC was confirmed. MANCR is significantly upregulated in PC cells under hypoxic conditions, which is closely linked to poor prognosis in patients with PC. Depletion of MANCR repressed in vitro proliferation, migration, and invasion of PC cells and in vivo growth of PC xenograft tumours. We further demonstrated that MANCR is localised in the cytoplasm and competitively binds miR-494, which directly targets SIRT1. Mechanically, the overexpression of SIRT1 improved the stability of the HIF-1α protein through deacetylation, leading to enhanced HIF-1α assembly. Moreover, MANCR underwent transcriptional regulation by HIF-1α in a hypoxic setting. This modulation was ascribed to HIF-1α binding to hypoxia response elements present in the MANCR promoter sequence. Data revealed the potential possibility of feedback between MANCR and HIF-1α, which may be conducive to hypoxia-induced oncogenicity and PC tumorigenesis, thereby providing a suitable therapeutic target.