Histone deacetylase inhibitor quisinostat activates caspase signaling and upregulates p53 acetylation to inhibit the proliferation of HepG2 cells

Histone deacetylase inhibitors: targeting epigenetic regulation in the treatment of acute leukemia

Acute leukemia (AL) is a rare yet perilous malignancy. Currently, the primary treatment for AL involves combination chemotherapy as the cornerstone of comprehensive measures, alongside hematopoietic stem cell transplantation as a radical approach. However, despite these interventions, mortality rates remain high, particularly among refractory/recurrent patients or elderly individuals with a poor prognosis. Acetylation, a form of epigenetic regulation, has emerged as a promising therapeutic avenue for treating AL. Recent studies have highlighted the potential of acetylation regulation as a novel treatment pathway. Histone deacetylase inhibitors (HDACis) play a pivotal role in modulating the differentiation and development of tumor cells through diverse pathways, simultaneously impacting the maturation and function of lymphocytes. HDACis demonstrate promise in enhancing survival rates and achieving a complete response in both acute myeloid leukemia and acute T-lymphoblastic leukemia patients. This article provides a comprehensive review of the advancements in HDACi therapy for AL, shedding light on its potential implications for clinical practice.

Research Progress on the Mechanism of Histone Deacetylases in Ferroptosis of Glioma

Glioma is the most prevalent primary malignant tumor of the central nervous system. While traditional treatment modalities such as surgical resection, radiotherapy, and chemotherapy have made significant advancements in glioma treatment, the prognosis for glioma patients remains often unsatisfactory. Ferroptosis, a novel form of programmed cell death, plays a crucial role in glioma and is considered to be the most functionally rich programmed cell death process. Histone deacetylases have emerged as a key focus in regulating ferroptosis in glioma. By inhibiting the activity of histone deacetylases, histone deacetylase inhibitors elevate acetylation levels of both histones and non-histone proteins, thereby influencing various cellular processes. Numerous studies have demonstrated that histone deacetylases are implicated in the development of glioma and hold promise for its treatment. This article provides an overview of research progress on the mechanism by which histone deacetylases contribute to ferroptosis in glioma.

Nano-Assembly of Quisinostat and Biodegradable Macromolecular Carrier Results in Supramolecular Complexes with Slow-Release Capabilities

Self-assembly of ionically charged small molecule drugs with water-soluble biodegradable polyelectrolytes into nano-scale complexes can potentially offer a novel and attractive approach to improving drug solubility and prolonging its half-life. Nanoassemblies of quisinostat with water-soluble PEGylated anionic polyphosphazene were prepared by gradient-driven escape of solvent resulting in the reduction of solvent quality for a small molecule drug. A study of binding, analysis of composition, stability, and release profiles was conducted using asymmetric flow field flow fractionation (AF4) and dynamic light scattering (DLS) spectroscopy. Potency assays were performed with WM115 human melanoma and A549 human lung cancer cell lines. The resulting nano-complexes contained up to 100 drug molecules per macromolecular chain and displayed excellent water-solubility and improved hemocompatibility when compared to co-solvent-based drug formulations. Quisinostat release time (complex dissociation) at near physiological conditions in vitro varied from 5 to 14 days depending on initial drug loading. Multimeric complexes displayed dose-dependent potency in cell-based assays and the results were analyzed as a function of complex concentration, as well as total content of drug in the system. The proposed self-assembly process may present a simple alternative to more sophisticated delivery modalities, namely chemically conjugated prodrug systems and nanoencapsulation-based formulations.

A novel therapeutic strategy for hepatocellular carcinoma: Immunomodulatory mechanisms of selenium and/or selenoproteins on a shift towards anti-cancer

Selenium (Se) is an essential trace chemical element that is widely distributed worldwide. Se exerts its immunomodulatory and nutritional activities in the human body in the form of selenoproteins. Se has increasingly appeared as a potential trace element associated with many human diseases, including hepatocellular carcinoma (HCC). Recently, increasing evidence has suggested that Se and selenoproteins exert their immunomodulatory effects on HCC by regulating the molecules of oxidative stress, inflammation, immune response, cell proliferation and growth, angiogenesis, signaling pathways, apoptosis, and other processes in vitro cell studies and in vivo animal studies. Se concentrations are generally low in tissues of patients with HCC, such as blood, serum, scalp hair, and toenail. However, Se concentrations were higher in HCC patient tissues after Se supplementation than before supplementation. This review summarizes the significant relationship between Se and HCC, and details the role of Se as a novel immunomodulatory or immunotherapeutic approach against HCC.

Death by histone deacetylase inhibitor quisinostat in tongue squamous cell carcinoma via apoptosis, pyroptosis, and ferroptosis

Tongue cancer is one of the most common oral malignancies. Quisinostat is a histone deacetylase inhibitor with antitumor activity. The aim of this study was to evaluate the effects of quisinostat on the viability of tongue squamous cell carcinoma (TSCC) cells (CAL-27, TCA-8113) in vitro and in vivo. Cell viability, cell morphological observation, scratch wound-healing assay, transwell migration assay, transmission electron microscope, flow cytometry and cellular reactive oxygen species were assessed in vitro. The results showed that quisinostat can significantly inhibit the viability, growth and migration of TSCC cells. And quisinostat could significantly induce TSCC cells apoptosis, pyroptosis, and ferroptosis. Quisinostat significantly inhibited tumor tissue growth in animal experiments. Up-regulation of the expression of Bax, cleaved-caspase3, caspase-1, p53, phospho-p53 and down-regulated of the expression of caspase-3, Bcl-2, GPX4 in cell lines and tumor tissues of nude mice were observed by Western blotting analysis. Up-regulation of the expression of caspase-1, Bax, cleaved-caspase3, p53 and down-regulated of the expression of ki67, caspase-3, Bcl-2, GPX4 in tumor tissues of nude mice were observed by immunohistochemistry. TUNEL analysis showed that quisinostat could increase the apoptosis rate in the tumor tissues of nude mice. Up-regulation of the expression of p53 and down-regulated expression of GPX4 in cell lines were observed by immunofluorescent staining, and the expression locations of p53 and GPX4 proteins in TSCC cells were observed. Based on these findings, quisinostat may be a potential drug for the treatment of tongue squamous cell carcinoma.

Xanthophyll β-Cryptoxanthin Inhibits Highly Refined Carbohydrate Diet-Promoted Hepatocellular Carcinoma Progression in Mice

SCOPE

β-Cryptoxanthin (BCX) can be cleaved by both β-carotene 15,15'-oxygenase (BCO1) and β-carotene 9',10'-oxygenase (BCO2), generating biological active vitamin A and apocarotenoids. We examined whether BCX feeding could inhibit diethylnitrosamine (DEN)-initiated, highly refined carbohydrate diet (HRCD)-promoted hepatocellular carcinoma (HCC) development, dependent or independent of BCO1/BCO2 activity.

METHODS AND RESULTS

Two-week-old male wild-type (WT) and BCO1^-/- /BCO2^-/- double knockout (DKO) mice are given a single intraperitoneal injection of DEN (25 mg kg^-1 body weight) to initiate hepatic carcinogenesis. At 6 weeks of age, all animals are fed HRCD (66.5% of energy from carbohydrate) with or without BCX for 24 weeks. BCX feeding increases hepatic vitamin A levels in WT mice, but not in DKO mice that shows a significant accumulation of hepatic BCX. Compared to their respective HRCD littermates, both WT and DKO fed BCX have significantly lower HCC multiplicity, average tumor size, and total tumor volume, and the steatosis scores. The chemopreventive effects of BCX are associated with increased p53 protein acetylation and decreased protein levels of lactate dehydrogenase and hypoxia-inducible factor-1α in tumors.

CONCLUSION

This study suggests that BCX feeding may alleviate HRCD-promoted HCC progression by modulating the acetylation of p53, hypoxic tumor microenvironment, and glucose metabolism, independent of BCO1/BCO2.

Metformin and 4SC-202 synergistically promote intrinsic cell apoptosis by accelerating ΔNp63 ubiquitination and degradation in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is the most common and aggressive epithelial tumor in the head and neck region with a rising incidence. Despite the advances in basic science and clinical research, the overall survival rate of OSCC remains low. Thus finding novel effective therapeutic agents for OSCC is necessary. In this study, we investigated the effects and mechanisms of combined metformin and 4SC-202 in OSCC. Our results showed that metformin and 4SC-202 synergistically suppressed the proliferation and promoted the intrinsic apoptosis of OSCC cells in vitro and in vivo. Importantly, the proteasome inhibitor MG132 impeded the ΔNp63-decreasing effects after metformin and 4SC-202 treatment, indicating that metformin and 4SC-202 could promote the degradation of ΔNp63 protein. Moreover, ubiquitination level of ΔNp63 increased after metformin or/and 4SC-202 administration. Furthermore, we revealed that ΔNp63 mediated anticancer effects of metformin and 4SC-202, as overexpression or suppression of ΔNp63 could attenuate or facilitate the apoptosis rate of OSCC under metformin or/and 4SC-202 treatment. Collectively, metformin and 4SC-202 synergistically promote intrinsic apoptosis through accelerating ubiquitin-mediated degradation of ΔNp63 in OSCC, and this co-treatment can serve as a potential therapeutic scheme for OSCC.

A novel benzamine lead compound of histone deacetylase inhibitor ZINC24469384 can suppresses HepG2 cells proliferation by upregulating NR1H4

Histone deacetylases (HDACs) can enzymatically transferred acetyl functional group from protein or lysine residues of histone, so they can regulate the expression of lots of genes. Now HDACs are used as drug targets and many HDAC inhibitors (HDACis) were approved for cancer therapy or in clinical trials. However, the physiological mechanisms and regulatory processes of HDACi anti-cancer effects are largely unexplored and uncompleted. Here we use the virtual screening workflow obtained 25 hit compounds and ZINC24469384 can significantly inhibit HDAC activity while arrest cell cycle at G1/S phase and significantly induced HepG2 cell apoptosis, time-course RNA-seq demonstrate that HepG2 cells transcriptionally respond to ZINC24469384. Pathway analysis of DEGs and DASGs reveal that NR1H4 may play an important role in ZINC24469384-induced anti-proliferation effect and is dramatically alleviated by down-regulating the SOCS2 expression and promoting STAT3 phosphorylation in knockdown NR1H4 HepG2 cells. Analysis based on TCGA database indicated that NR1H4 and SOCS2 were downregulated in liver cancer, this suggest NR1H4 and SOCS2 may play an important role in tumorigenesis. These results indicated that ZINC24469384 is a novel benzamine lead compound of HDACi and provides a novel mechanism for HDACi to inhibit cancer.

Histone deacetylase 7 inhibits plakoglobin expression to promote lung cancer cell growth and metastasis

Plakoglobin is a tumor suppressor gene in lung cancer; however, the mechanism by which it is downregulated in lung cancer is largely unknown. The aim of the present study was to investigate whether histone deacetylases (HDACs) regulate plakoglobin expression in lung cancer. The effects of overexpression or knockdown of HDAC7 on plakoglobin were determined using stably transfected lung cancer cell lines. Chromatin immunoprecipitation assays were performed to elucidate the mechanisms underlying the HDAC7‑induced suppression of plakoglobin. A Cell Counting Kit‑8 and Transwell assays were performed, and a nude mouse in vivo model was established to investigate the role of the HDAC7/plakoglobin pathway in cell migration, invasion and metastasis. Ectopic expression of HDAC7 was identified to suppress mRNA and protein levels of plakoglobin in lung cancer cells, whereas silencing HDAC7 with short hairpin RNA increased the expression of plakoglobin. HDAC7 was proposed to suppressed plakoglobin by directly binding to its promoter. Overexpression or knockdown of HDAC7 promoted or inhibited cell proliferation, migration and invasion, respectively. Furthermore, knockdown of HDAC7 significantly suppressed tumor growth and metastasis in vivo. In addition, overexpression of plakoglobin significantly reduced the enhanced cell proliferation, migration and invasion induced by ectopic HDAC7. In conclusion, suppression of plakoglobin by HDAC7 promoted the proliferation, migration, invasion and metastasis in lung cancer. This novel axis of HDAC7/plakoglobin may be valuable in the development of novel therapeutic strategies for treating patients with lung cancer.

Anticancer effect of histone deacetylase inhibitor scriptaid as a single agent for hepatocellular carcinoma

Recurrence is one of the major causes of poor prognosis for patients with hepatocellular carcinoma (HCC), and drug resistance is closely associated with disease recurrence. Histone deacetylase (HDAC) inhibitor scriptaid functions as an anticancer agent in many different types of tumors, but its possible roles in HCC progression have not been explored to date. Herein, we show that HDAC inhibitor scriptaid decreases HCC cell proliferation and induces cell cycle G₂/M-phase arrest in a dose-dependent manner. Furthermore, scriptaid triggered HCC cell death via transcriptional activation of p21 and subsequent elevated global H3Ac levels. Importantly, we found that scriptaid showed robust antitumor activity against HCC. Thus, our findings indicate that HDAC inhibitor scriptaid could be an important potential candidate for treatment of HCC patients.

Modification of Epigenetic Histone Acetylation in Hepatocellular Carcinoma

Cells respond to various environmental factors such as nutrients, food intake, and drugs or toxins by undergoing dynamic epigenetic changes. An imbalance in dynamic epigenetic changes is one of the major causes of disease, oncogenic activities, and immunosuppressive effects. The aryl hydrocarbon receptor (AHR) is a unique cellular chemical sensor present in most organs, and its dysregulation has been demonstrated in multiple stages of tumor progression in humans and experimental models; however, the effects of the pathogenic mechanisms of AHR on epigenetic regulation remain unclear. Apart from proto-oncogene activation, epigenetic repressions of tumor suppressor genes are involved in tumor initiation, procession, and metastasis. Reverse epigenetic repression of the tumor suppressor genes by epigenetic enzyme activity inhibition and epigenetic enzyme level manipulation is a potential path for tumor therapy. Current evidence and our recent work on deacetylation of histones on tumor-suppressive genes suggest that histone deacetylase (HDAC) is involved in tumor formation and progression, and treating hepatocellular carcinoma with HDAC inhibitors can, at least partially, repress tumor proliferation and transformation by recusing the expression of tumor-suppressive genes such as TP53 and RB1.