SOD1 inhibition enhances sorafenib efficacy in HBV-related hepatocellular carcinoma by modulating PI3K/Akt/mTOR pathway and ROS-mediated cell death.

Hepatitis B Virus (HBV) infection significantly elevates the risk of hepatocellular carcinoma (HCC), with the HBV X protein (HBx) playing a crucial role in cancer progression. Sorafenib, the primary therapy for advanced HCC, shows limited effectiveness in HBV-infected patients due to HBx-related resistance. Numerous studies have explored combination therapies to overcome this resistance. Sodium diethyldithiocarbamate (DDC), known for its anticancer effects and its inhibition of superoxide dismutase 1 (SOD1), is hypothesized to counteract sorafenib (SF) resistance in HBV-positive HCCs. Our research demonstrates that combining DDC with SF significantly reduces HBx and SOD1 expressions in HBV-positive HCC cells and human tissues. This combination therapy disrupts the PI3K/Akt/mTOR signalling pathway and promotes apoptosis by increasing reactive oxygen species (ROS) levels. These cellular changes lead to reduced tumour viability and enhanced sensitivity to SF, as evidenced by the synergistic suppression of tumour growth in xenograft models. Additionally, DDC-mediated suppression of SOD1 further enhances SF sensitivity in HBV-positive HCC cells and xenografted animals, thereby inhibiting cancer progression more effectively. These findings suggest that the DDC-SF combination could serve as a promising strategy for overcoming SF resistance in HBV-related HCC, potentially optimizing therapy outcomes.

Fasudil and viscosity of gelatin promote hepatic differentiation by regulating organelles in human umbilical cord matrix-mesenchymal stem cells.

BACKGROUND: Human mesenchymal stem cells originating from umbilical cord matrix are a promising therapeutic resource, and their differentiated cells are spotlighted as a tissue regeneration treatment. However, there are limitations to the medical use of differentiated cells from human umbilical cord matrix-mesenchymal stem cells (hUCM-MSCs), such as efficient differentiation methods. METHODS: To effectively differentiate hUCM-MSCs into hepatocyte-like cells (HLCs), we used the ROCK inhibitor, fasudil, which is known to induce endoderm formation, and gelatin, which provides extracellular matrix to the differentiated cells. To estimate a differentiation efficiency of early stage according to combination of gelatin and fasudil, transcription analysis was conducted. Moreover, to demonstrate that organelle states affect differentiation, we performed transcription, tomographic, and mitochondrial function analysis at each stage of hepatic differentiation. Finally, we evaluated hepatocyte function based on the expression of mRNA and protein, secretion of albumin, and activity of CYP3A4 in mature HLCs. RESULTS: Fasudil induced endoderm-related genes (GATA4, SOX17, and FOXA2) in hUCM-MSCs, and it also induced lipid droplets (LDs) inside the differentiated cells. However, the excessive induction of LDs caused by fasudil inhibited mitochondrial function and prevented differentiation into hepatoblasts. To prevent the excessive LDs formation, we used gelatin as a coating material. When hUCM-MSCs were induced into hepatoblasts with fasudil on high-viscosity (1%) gelatin-coated dishes, hepatoblast-related genes (AFP and HNF4A) showed significant upregulation on high-viscosity gelatin-coated dishes compared to those treated with low-viscosity (0.1%) gelatin. Moreover, other germline cell fates, such as ectoderm and mesoderm, were repressed under these conditions. In addition, LDs abundance was also reduced, whereas mitochondrial function was increased. On the other hand, unlike early stage of the differentiation, low viscosity gelatin was more effective in generating mature HLCs. In this condition, the accumulation of LDs was inhibited in the cells, and mitochondria were activated. Consequently, HLCs originated from hUCM-MSCs were genetically and functionally more matured in low-viscosity gelatin. CONCLUSIONS: This study demonstrated an effective method for differentiating hUCM-MSCs into hepatic cells using fasudil and gelatin of varying viscosities. Moreover, we suggest that efficient hepatic differentiation and the function of hepatic cells differentiated from hUCM-MSCs depend not only on genetic changes but also on the regulation of organelle states.

Collagenase and Tyrosinase Inhibitory Compounds from Fish Gut Bacteria Ruegeria atlantica and Pseudoalteromonas neustonica.

Ruegeria atlantica and Pseudoalteromonas neustonica are fish gut bacteria that have been isolated from the guts of Pagrus major and Acanthopagrus schlegelii, respectively. A total of 22 compounds (1-22) were isolated from these two bacteria; 16 compounds (1-16) from R. atalantica and 6 compounds (17-22) from P. neustonica. Their chemical structures were elucidated by spectroscopic and spectrometric data analysis and chemical synthesis. Compounds 11 and 13 showed strong collagenase inhibitory activity, with 31.91% and 36.43% at 20 µM, respectively, comparable to or surpassing that of the positive control epigallocatechin gallate (EGCG, 34.66%). Also, compounds 11 and 14 exhibited a mild tyrosinase inhibitory effect of 6.73% and 13.68%, respectively. All of the tested compounds displayed no significant antibacterial activity against Escherichia coli and Bacillus subtilis up to 100 µM. The collagenase- and tyrosinase-inhibitory compound 11, cyclo(l-Pro-d-Leu), was found to be stable under heat (50 °C) and UV light (254 and 365 nm) for up to 6 days. These results indicate that compound 11 could be developed into a cosmeceutical with antiaging effects.