Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer, accounting for 80–90% of cases. Mutations are commonly found in the signaling regulating the PI3K/Akt pathway, leading to oncogenic cell proliferation and survival. Key transcription factors that are negatively regulated downstream of PI3K/Akt are members of the forkhead box O family (FOXO). FOXOs were initially considered as tumor suppressors by inducing cell cycle arrest and apoptosis. However, there is increasing evidence showing that FOXOs, especially FOXO3, can support tumorigenesis. To understand the roles of FOXO3 in liver tumorigenesis and hepatocarcinogenesis, we analyzed HCC patient specimens and also established a doxycycline-regulated transgenic mouse model with hepatocyte-specific FOXO3 expression in a constitutively active form. We found that FOXO3 protein is significantly overexpressed and activated in livers of HCC patients. Hepatic activation of FOXO3 induced extensive hepatic damage and elevated gene expression of several HCC-associated factors. Furthermore, FOXO3 expression enhanced hepatotoxicin-induced tumorigenesis. Mechanistically, FOXO3 activation caused oxidative stress and DNA damage and triggered positive feedback-loop for Akt activation as well as mTORC2 activation. Interestingly, FOXO3 activated not only reactive oxygen species (ROS)-promoting pathways, but also ROS-eliminating systems, which can be associated with the activation of the pentose phosphate pathway. FOXO3 is a master regulator of ROS in a ‘carrot and stick’ manner; on one side avoiding cellular crisis while also supporting hepatocellular carcinogenesis. Clinically, we suggest analyzing FOXO3 activation status in patients with liver diseases, in addition to PI3K/Akt signaling. Personalized therapy of FOXO3 inhibition may be a reasonable, depending on the activation status of FOXO3.

In this study, highly monodispersed spherical bioactive glass nanoparticles (BGS) with a particle size of 408 ± 36 nm were synthesized using a modified Stöber method. The BGS was then functionalized with lysozyme (LY) via a simple electrostatic interaction routine under selected conditions. The LY-functionalized BGS (LY-BGS) exhibited monodispersity, spherical morphology and homogeneity in size. The incorporated content of LY could be tailored conveniently by adjusting the initial concentration of the LY precursor for functionalization. Hydroxyapatite (HA) formed on the LY-BGS after soaking in simulated body fluid (SBF) for 7 d, but the formation was retarded compared to the non-functionalized BGS. The LY-BGS showed antibacterial activity towards Gram-positive B. subtilis and >90% of the bacteria was killed within 24 h after culture with the LY-BGS at a concentration of 1 mg ml ⁻¹ . The LY-BGS also showed cytotoxicity towards the human hepatocellular carcinoma (HepG2) cell line. In addition, the relative cytotoxicity increased with an increase in the concentration of the LY-BGS in contact with the cells. As a comparison, the LY-BGS exhibited reduced or no cytotoxicity towards human umbilical vein endothelial cells (HUVECs) at the same concentration with respect to the HepG2 groups. Notably, the relative cell viability of HepG2 was 45.9% after exposure to the LY-BGS at a concentration of 10 μ g ml ⁻¹ for 24 h, while no decrease in relative viability for the HUVECs was observed under the same conditions. This cytotoxicity window between cancerous cells and healthy cells could be expected for cancer treatment. Furthermore, the antibacterial properties and the bioactivity of LY-BGS make it a promising material for biomedical applications, particularly in the treatment of bone defects caused by tumors.

Brahma-related gene 1 (Brg1), a catalytic subunit of the SWItch/Sucrose Non-Fermentable (SWI/SNF) complex, is known to be involved in proliferative cell processes. Liver regeneration is initiated spontaneously after injury and leads to a strong proliferative response. In this study, a hepatocyte-specific Brg1 gene knockout mouse model was used to analyse the role of Brg1 in liver regeneration by performing a 70% partial hepatectomy (PH). After PH, Brg1 was significantly upregulated in wildtype mice. Mice with hepatocyte-specific Brg1 gene knockout showed a significantly lower liver to body weight ratio 48 h post-PH concomitant with a lower hepatocellular proliferation rate compared to wildtype mice. RNA sequencing demonstrated that Brg1 controlled hepatocyte proliferation through the regulation of the p53 pathway and several cell cycle genes. The data of this study reveal a crucial role of Brg1 for liver regeneration by promoting hepatocellular proliferation through modulation of cell cycle genes and, thus, identify Brg1 as potential target for therapeutic approaches.

Peroxisome Proliferator-Activated Receptor gamma (PPARγ) is a nuclear receptor demonstrated to play an important role in various biological processes. The aim of this study was to determine the effect of PPARγ on liver regeneration upon partial hepatectomy (PH) in mice. Mice were subjected to two-thirds PH. Before surgery, mice were either treated with the PPARγ agonist rosiglitazone, the PPARγ antagonist GW9662 alone, or with the c-met inhibitor SGX523. Liver-to-body-weight ratio, lab values, and proliferation markers were assessed. Components of the PPARγ-specific signaling pathway were identified by western blot and qRT-PCR. Our results show that liver regeneration is being inhibited by rosiglitazone and accelerated by GW9662. Inhibition of c-Met by SGX523 treatment abrogates GW9662-induced liver regeneration and hepatocyte proliferation. Hepatocyte growth factor (HGF) protein levels were significantly downregulated after rosiglitazone treatment. Activation of HGF/c-Met pathways by phosphorylation of c-Met and ERK1/2 were inhibited in rosiglitazone-treated mice. In turn, blocking phosphorylation of c-Met significantly abrogated the augmented effect of GW9662 on liver regeneration. Our data support the concept that PPARγ abrogates liver growth and hepatocellular proliferation by inhibition of the HGF/c-Met/ERK1/2 pathways. These pathways may represent potential targets in response to liver disease and could impact on the development of molecular therapies.