HDAC inhibitor cowanin extracted from G. fusca induces apoptosis and autophagy via inhibition of the PI3K/Akt/mTOR pathways in Jurkat cells

Radix Actinidiae chinensis induces the autophagy and apoptosis in renal cell carcinoma cells

BACKGROUND

Renal cell carcinoma (RCC) is a malignant tumor. Radix Actinidiae chinensis (RAC) is the root of Actinidia arguta (Sieb. et Zucc) Planch. ex Miq. In clinical research, RAC was confirmed to have a certain anti-tumor effect, including liver cancer and cholangiocarcinoma. This study investigated the anticancer effect and mechanism of RAC in RCC cells.

METHODS

The 786-O and A498 cells were intervened with varying concentrations of RAC (0-100 mg/mL) to detect the half maximal inhibitory concentration (IC50) of RAC. The cells were then co-cultured with 0-50 mg/mL RAC for 0-72 h to assess the effect of RAC on cell viability using the cell counting kit-8. The effects on cell proliferation, cell cycle or apoptosis, migration or invasion, and autophagy were detected using cloning, flow cytometry, Transwell, AOPI assay and Western blot. The number of autophagolysosomes was quantified using a transmission electron microscope. PI3K/AKT/mTOR pathway-related proteins were detected by Western blot. Additionally, an autophagy inhibitor 3-MA was used to explore the underlying mechanism of RAC.

RESULTS

IC50 values of RAC in 786-O and A498 were 14.76 mg/mL and 13.09 mg/mL, respectively. RAC demonstrated the ability to reduce the cell malignant phenotype of RCC cells, blocked the S phase of cells, promoted apoptosis and autophagy in cells. Furthermore, RAC was observed to increase autophagy-related proteins LC3II/I and Beclin-1, while decreasing the level of P62. The expression of apoptosis-related proteins was increased, while the ratios of p-PI3K/PI3K, p-AKT/AKT, p-mTOR/mTOR, p-P38/P38 and p-ERK/ERK were reduced by RAC. However, the addition of 3-MA reduced the apoptosis and autophagy- promotion effects of RAC on RCC cells.

CONCLUSION

RAC induced the apoptosis and autophagy, to inhibit the progression of RCC cells. This study may provide a theoretical and experimental basis for clinical anti-cancer application of RAC for RCC.

Hydroxytyrosol ameliorates stress-induced liver injury through activating autophagy via HDAC1/2 inhibition

Hydroxytyrosol (HT), a phenolic extra-virgin olive oil compound used as a food supplement, has been recognized to protect liver function and alleviate stress-induced depressive-like behaviors. However, its protective effects against stress-induced liver injury (SLI) remain unknown. Here, the anti-SLI effect of HT was evaluated in mice with chronic unpredictable mild stress-induced SLI. Network pharmacology combined with molecular docking was used to clarify the underlying mechanism of action of HT against SLI, followed by experimental verification. The results showed that accompanying with the alleviation of HT on stress-induced depressive-like behaviors, HT was confirmed to exert the protective effects against SLI, as represented by reduced serum corticosterone (CORT), aspartate aminotransferase and alanine aminotransferase activities, as well as repair of liver structure, inhibition of oxidative homeostasis collapse, and inflammation reaction in the liver. Furthermore, core genes including histone deacetylase 1 and 2 (HDAC1/2), were identified as potential targets of HT in SLI based on bioinformatic screening and simulation. Consistently, HT significantly inhibited HDAC1/2 expression to maintain mitochondrial dysfunction in an autophagy-dependent manner, which was confirmed in a CORT-induced AML-12 cell injury and SLI mice models combined with small molecule inhibitors. We provide the first evidence that HT inhibits HDAC1/2 to induce autophagy in hepatocytes for maintaining mitochondrial dysfunction, thus preventing inflammation and oxidative stress for exerting an anti-SLI effect. This constitutes a novel therapeutic modality to synchronously prevent stress-induced depression-like behaviors and liver injury, supporting the advantaged therapeutic potential of HT.

SOX4/HDAC2 Axis Enhances Cell Survivability and Reduces Apoptosis by Activating AKT/MAPK Signaling in Colorectal Cancer

BACKGROUND

Increased SOX4 (SRY-related HMG-box) activity aids cellular transformation and metastasis. However, its specific functions and downstream targets remain to be completely elusive in colorectal cancer (CRC).

AIMS

To investigate the role of SOX4 in CRC progression and the underlying mechanism.

METHODS

In the current study, online available datasets of CRC patients were explored to check the expression status of SOX4. To investigate the further functions, SOX4 was overexpressed and knocked down in CRC cells. Colony formation assay, flowcytometry analysis, and MTT assay were used to check for proliferation and apoptosis. Acridine orange staining was done to check the role of SOX4 in autophagy induction. Furthermore, western blot, qRT-PCR, and bioinformatic analysis was done to elucidate the downstream molecular mechanism of SOX4.

RESULTS

GEPIA database showed enhanced expression of SOX4 mRNA in CRC tumor, and the human protein atlas (HPA) showed strong staining of SOX4 protein in tumor when compared to the normal tissue. Ectopic expression of SOX4 enhanced colony formation ability as well as rescued cells from apoptosis. SOX4 overexpressed cells showed the formation of acidic vesicular organelles (AVOs) which indicated autophagy. Further results revealed the activation of p-AKT/MAPK molecules upon overexpression of SOX4. SOX4 expression was found to be positively correlated with histone deacetylase 2 (HDAC2). Knockdown of SOX4 or HDAC2 inhibition induced apoptosis, revealed by decrease in BCL2 and increase in BAX expression, and inactivated the p-AKT/MAPK signaling.

CONCLUSION

The study uncovers that SOX4/HDAC2 axis improves cell survivability and reduces apoptosis via activation of the p-AKT/MAPK pathway.

Synergistic effect of docetaxel combined with a novel multi-target inhibitor CUDC-101 on inhibiting human prostate cancer

Histone deacetylases (HDACs) are commonly overexpressed in several types of human cancers, including prostate cancer (PCa). Histone deacetylase inhibitors (HDACis) are emerging as promising tools for cancer therapy. However, there is still a need to understand their anti-tumor effects and the mechanisms underlying their action. In our study, we investigated the effects of co-treatment with CUDC-101 and docetaxel (DTX) on cell growth, clonogenicity, invasion and migration of PCa cells both in vitro, and in a xenograft mouse model. We found that the combination of CUDC-101 and DTX significantly reduced tumor growth, as evidenced by lower tumor weight and volumes. Moreover, apoptotic cell death was increased in the combination group compared to either drug alone or control. Mechanistically, we observed that the combined treatment of CUDC-101 with DTX suppressed the progression of PCa cell lines through the AKT and ERK1/2 signaling pathways. Additionally, this combination treatment reversed EMT by modulating the expression of key markers such as E-cadherin, vimentin, Snail and MMP-9. To conclude, these results demonstrated that the combination of CUDC-101 with DTX had a synergistic and significantly improved anti-carcinogenic effect. This combination may serve as a potential strategy for clinical treatment and prognosis improvement in PCa.

Potential of Synthetic and Natural Compounds as Novel Histone Deacetylase Inhibitors for the Treatment of Hematological Malignancies

Histone deacetylases (HDACs) and histone acetyltransferases (HATs) are enzymes that remove or add acetyl groups to lysine residues of histones, respectively. Histone deacetylation causes DNA to more snugly encircle histones and decreases gene expression, whereas acetylation has the opposite effect. Through these small alterations in chemical structure, HATs and HDACs regulate DNA expression. Recent research indicates histone deacetylase inhibitors (HDACis) may be used to treat malignancies, including leukemia, B-cell lymphoma, virus-associated tumors, and multiple myeloma. These data suggest that HDACis may boost the production of immune-related molecules, resulting in the growth of CD8-positive T-cells and the recognition of nonreactive tumor cells by the immune system, thereby diminishing tumor immunity. The argument for employing epigenetic drugs in the treatment of acute myeloid leukemia (AML) patients is supported by evidence that both epigenetic changes and mutations in the epigenetic machinery contribute to AML etiology. Although hypomethylating drugs have been licensed for use in AML, additional epigenetic inhibitors, such as HDACis, are now being tested in humans. Preclinical studies evaluating the efficacy of HDACis against AML have shown the ability of specific agents, such as anobinostat, vorinostat, and tricostatin A, to induce growth arrest, apoptosis, autophagy and cell death. However, these inhibitors do not seem to be successful as monotherapies, but instead achieve results when used in conjunction with other medications. In this article, we discuss the mounting evidence that HDACis promote extensive histone acetylation, as well as substantial increases in reactive oxygen species and DNA damage in hematological malignant cells. We also evaluate the potential of various natural product-based HDACis as therapeutic agents to combat hematological malignancies.

HDAC inhibitors Panobinostat and Romidepsin enhance tax transcription in HTLV-1-infected cell lines and freshly isolated patients’ T-cells

The viral transactivator Tax plays a key role in HTLV-1 reactivation and de novo infection. Previous approaches focused on the histone deacetylase inhibitor (HDACi) Valproate as a latency-reversing agent to boost Tax expression and expose infected cells to the host’s immune response. However, following treatment with Valproate proviral load decreases in patients with HAM/TSP were only transient. Here, we hypothesize that other compounds, including more potent and selective HDACi, might prove superior to Valproate in manipulating Tax expression. Thus, a panel of HDACi (Vorinostat/SAHA/Zolinza, Panobinostat/LBH589/Farydak, Belinostat/PXD101/Beleodaq, Valproate, Entinostat/MS-275, Romidepsin/FK228/Istodax, and MC1568) was selected and tested for toxicity and potency in enhancing Tax expression. The impact of the compounds was evaluated in different model systems, including transiently transfected T-cells, chronically HTLV-1-infected T-cell lines, and freshly isolated PBMCs from HTLV-1 carriers ex vivo. We identified the pan-HDACi Panobinostat and class I HDACi Romidepsin as particularly potent agents at raising Tax expression. qRT-PCR analysis revealed that these inhibitors considerably boost tax and Tax-target gene transcription. However, despite this significant increase in tax transcription and histone acetylation, protein levels of Tax were only moderately enhanced. In conclusion, these data demonstrate the ability of Panobinostat and Romidepsin to manipulate Tax expression and provide a foundation for further research into eliminating latently infected cells. These findings also contribute to a better understanding of conditions limiting transcription and translation of viral gene products.