Cell-permeated peptide P-T3H2 inhibits malignancy on hepatocellular carcinoma through stabilizing HNF4α protein.

Objectives: Hepatocyte nuclear factor 4α (HNF4α) is a key regulator of hepatocyte function and has a strong therapeutic effect on hepatocellular carcinoma (HCC) by inducing the differentiation of hepatoma cell into hepatocytes. Our previous study showed that Tribbles homolog 3 (TRIB3) directly interacts with and promotes the degradation of HNF4α in non-alcoholic fatty liver disease (NAFLD). Disrupting the TRIB3-HNF4α interaction by a cell-permeating peptide, called P-T3H2, stabilized HNF4α protein. This study aimed to assess the anti-tumor impact of P-T3H2 in HCC.

Methods: The expression of TRIB3 and HNF4α was evaluated using western blot and immunohistochemistry (IHC). Hepatic functions and cellular senescence of HCC cells were evaluated through periodic acid-Schiff (PAS) staining, acetylated low-density lipoprotein (ac-LDL) uptake and senescence-associated β-galactosidase (SA-β-gal) activity staining, respectively. RNA-Seq analysis was performed to identify differentially expressed genes in Huh7 cells treated with P-T3H2. The impact of P-T3H2 on HCC malignancy was assessed in vitro and in vivo.

Results: TRIB3 exhibited a negative correlation with HNF4α in both human and mouse HCC tissues. The administration of P-T3H2 significantly inhibited the malignancy of HCC cells. Additionally, P-T3H2 stabilized HNF4α protein and facilitated the restoration of hepatic functions and the cellular senescence in HCC cells. RNA-Seq analysis demonstrated that P-T3H2 enhanced the transcriptional activity of HNF4α in HCC. Furthermore, P-T3H2 effectively suppressed the carcinogenesis and progression of HCC in mice.

Conclusion: P-T3H2 suppressed HCC progression through the stabilization of HNF4α protein and may be a promising therapeutic candidate for clinical application in the treatment of HCC.