HN1-mediated activation of lipogenesis through Akt-SREBP signaling promotes hepatocellular carcinoma cell proliferation and metastasis.

ABSTRACT

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths worldwide, with more than 800,000 deaths each year, and its 5-year survival rate is less than 12%. The role of the HN1 gene in HCC has remained elusive, despite its upregulation in various cancer types. In our investigation, we identified HN1's heightened expression in HCC tissues, which, upon overexpression, fosters cell proliferation, migration, and invasion, unveiling its role as an oncogene in HCC. In addition, silencing HN1 diminished the viability and metastasis of HCC cells, whereas HN1 overexpression stimulated their growth and invasion. Gene expression profiling revealed HN1 silencing downregulated 379 genes and upregulated 130 genes, and suppressive proteins associated with the lipogenic signaling pathway networks. Notably, suppressing HN1 markedly decreased the expression levels of SREBP1 and SREBP2, whereas elevating HN1 had the converse effect. This dual modulation of HN1 affected lipid formation, hindering it upon HN1 silencing and promoting it upon HN1 overexpression. Moreover, HN1 triggers the Akt pathway, fostering tumorigenesis via SREBP1-mediated lipogenesis and silencing HN1 effectively curbed HCC tumor growth in mouse xenograft models by deactivating SREBP-1, emphasizing the potential of HN1 as a therapeutic target, impacting both external and internal factors, it holds promise as an effective therapeutic strategy for HCC.