Design, synthesis, and biological evaluation of β-carboline 1,3,4-oxadiazole based hybrids as HDAC inhibitors with potential antitumor effects

Vorinostat, a potential hormetin, extends lifespan and enhances stress resistance via the SKN-1 pathway in Caenorhabditis elegans

Vorinostat, a pan histone deacetylases (HDACs) inhibitor clinically approved for cutaneous T-cell lymphoma, exerts therapeutic effects by inducing tumor cell death and cycle arrest. Intriguingly, a previously unrecognized hormetic role of low-dose vorinostat in Caenorhabditis elegans. Subtoxic concentrations of vorinostat (1 μM) significantly extended lifespan, enhanced healthspan, and improved resistance to oxidative and heat stress, while ameliorating Aβ-induced paralysis. qPCR analysis demonstrated dose-dependent bidirectional regulation of stress-resistance genes (sod-3, hsp-16.2, skn-1, gst-4, act-1), with low doses of vorinostat upregulating these genes whereas higher doses (10 μM) exerted suppressive or neutral effects. Mechanistically, vorinostat-induced hormesis required functional SKN-1 signaling, as evidenced by its capacity to activate skn-1 and downstream targets (hsp-16.2, gst-4, act-1). Crucially, RNAi-mediated skn-1 knockdown completely abolished the pro-longevity and stress-resistant phenotypes. These findings establish vorinostat as a novel hormetin that enhances organismal resilience through SKN-1 pathway activation, providing new insights into HDAC inhibitor biology and aging intervention strategies.

Exploring β-carboline hybrids and their derivatives: A review on synthesis and anticancer efficiency

β-Carboline is a crucial compound in medicinal chemistry known for its versatile pharmacological activities. Recent research has focused on hybrid molecules incorporating a β-carboline scaffold linked to other pharmacophore moieties. These hybrid compounds have demonstrated diverse therapeutic properties, including anticancer, antianxiety, antimalarial, antidepressant, anti-inflammatory, antileishmanial, and antioxidant effects. This review highlights studies conducted from 2014 to the present with a particular emphasis on the development of β-carboline hybrid compounds and their derivatives as potent anticancer agents. The structure-activity relationship (SAR) analysis reveals that these hybrids exhibit significant cytotoxicity against various cancer cell lines. This review aims to inspire further research into the novel synthesis and evolution of β-carboline hybrids and their derivatives, potentially leading to new therapeutic advancements.

Effect and mechanism of novel HDAC inhibitor ZDLT-1 in colorectal cancer by regulating apoptosis and inflammation

BACKGROUND

Histone deacetylase (HDAC) is a potential target for Colorectal Cancer (CRC) molecular target therapy, dehydroharmine derivative ZDLT-1 was designed to inhibit CRC cell proliferation by inhibiting HDAC target. This study aimed to explore the effect of ZDLT-1 could induce apoptosis in CRC in vitro and in vivo, and determine the mechanism of ZDLT-1.

METHODS

First, MTT assay, colony formation, wound healing, Transwell assay, Hoechst33342 staining and Annexin V-FITC/PI double staining assay were used to investigate the in vitro effect of ZDLT-1. Second, the toxicity and the anti-tumor effect of ZDLT-1 by subcutaneous tumorigenesis assay were used to determine the in vivo effect of ZDLT-1. In terms of mechanism, we evaluated the effect of ZDLT-1 on HDAC downstream proteins such as HIF-1α, NF-κB, Cleaved-Caspase-3/9, GSDMD and acetylated histone by immunofluorescence and Western blot assessments.

RESULTS

This study confirmed that ZDLT-1 had anti-tumor activity by inhibiting cell proliferation in vitro and solid tumor growth in vivo. Furthermore, ZDLT-1 can inhibit CRC cell invasion, migration and apoptosis in vitro. Moreover, ZDLT-1 can promote the expression of apoptosis proteins in HIF-1α/Caspase-3/Caspase-9 pathway and inhibit the expression of tumor-related immune proteins mainly in NF-κB/GSDMD/GSDME pathway.

CONCLUSION

ZDLT-1 as HDAC inhibitor could suppresses CRC cell growth in vivo and in vitro by triggering HIF-1α/Caspase-3/Caspase-9 pathway in promoting apoptosis, and triggering NF-κB/GSDMD/GSDME pathway in inhibiting tumor inflammation. Our results propose dehydroharmine derivative ZDLT-1 as a promising therapeutic small molecular agent for CRC.

Emerging therapeutic strategies in cancer therapy by HDAC inhibition as the chemotherapeutic potent and epigenetic regulator

In developing new cancer medications, attention has been focused on novel epigenetic medicines called histone deacetylase (HDAC) inhibitors. Our understanding of cancer behavior is being advanced by research on epigenetics, which also supplies new targets for improving the effectiveness of cancer therapy. Most recently published patents emphasize HDAC selective drugs and multitarget HDAC inhibitors. Though significant progress has been made in emerging HDAC selective antagonists, it is urgently necessary to find new HDAC blockers with novel zinc-binding analogues to avoid the undesirable pharmacological characteristics of hydroxamic acid. HDAC antagonists have lately been explored as a novel approach to treating various diseases, including cancer. The complicated terrain of HDAC inhibitor development is summarized in this article, starting with a discussion of the many HDAC isotypes and their involvement in cancer biology, followed by a discussion of the mechanisms of action of HDAC inhibitors, their current level of development, effect of miRNA, and their combination with immunotherapeutic.

Recent developments of hydroxamic acid hybrids as potential anti-breast cancer agents

Histone deacetylase inhibitors not only possess favorable effects on modulating tumor microenvironment and host immune cells but also can reactivate the genes silenced due to deacetylation and chromatin condensation. Hydroxamic acid hybrids as promising histone deacetylase inhibitors have the potential to address drug resistance and reduce severe side effects associated with a single drug molecule due to their capacity to simultaneously modulate multiple targets in cancer cells. Accordingly, rational design of hydroxamic acid hybrids may provide valuable therapeutic interventions for the treatment of breast cancer. This review aimed to provide insights into the in vitro and in vivo anti-breast cancer therapeutic potential of hydroxamic acid hybrids, together with their mechanisms of action and structure-activity relationships, covering articles published from 2020 to the present.

Hydroxamic acid hybrids: Histone deacetylase inhibitors with anticancer therapeutic potency

Histone deacetylases (HDACs), a class of enzymes responsible for the removal of acetyl functional groups from the lysine residues in the amino-terminal tails of core histones, play a critical role in the modulation of chromatin architecture and the regulation of gene expression. Dysregulation of HDAC expression has been closely associated with the development of various cancers. Histone deacetylase inhibitors (HDACis) could regulate diverse cellular pathways, cause cell cycle arrest, and promote programmed cell death, making them promising avenues for cancer therapy with potent efficacy and favorable toxicity profiles. Hybrid molecules incorporating two or more pharmacophores in one single molecule, have the potential to simultaneously inhibit two distinct cancer targets, potentially overcome drug resistance and minimize drug-drug interactions. Notably, hydroxamic acid hybrids, exemplified by fimepinostat and tinostamustine as potential HDACis, could exert the anticancer effects through induction of apoptosis, differentiation, and growth arrest in cancer cells, representing useful scaffolds for the discovery of novel HDACis. The purpose of this review is to summarize the current scenario of hydroxamic acid hybrids as HDACis with anticancer therapeutic potential developed since 2020 to facilitate further rational exploitation of more effective candidates.

Technologies of targeting histone deacetylase in drug discovery: Current progress and emerging prospects

Histone deacetylases (HDACs) catalyze the hydrolysis of acetyl-l-lysine side chains in histones and non-histones, which are key to epigenetic regulation in humans. Targeting HDACs has emerged as a promising strategy for treating various types of cancer, including myeloma and hematologic malignancies. At present, numerous small molecule inhibitors targeting HDACs are actively being investigated in clinical trials. Despite their potential efficacy in cancer treatment, HDAC inhibitors suffer from multi-directional selectivity and preclinical resistance issues. Hence, developing novel inhibitors based on cutting-edge medicinal chemistry techniques is essential to overcome these limitations and improve clinical outcomes. This manuscript presents an extensive overview of the properties and biological functions of HDACs in cancer, provides an overview of the current state of development and limitations of clinical HDAC inhibitors, and analyzes a range of innovative medicinal chemistry techniques that are applied. These techniques include selective inhibitors, dual-target inhibitors, proteolysis targeting chimeras, and protein-protein interaction inhibitors.

Synthesis, Anticancer Activity and Molecular Docking Studies of Novel N-Mannich Bases of 1,3,4-Oxadiazole Based on 4,6-Dimethylpyridine Scaffold

Cancer is one of the greatest challenges in modern medicine today. Difficult and long-term treatment, the many side effects of the drugs used and the growing resistance to treatment of neoplastic cells necessitate new approaches to therapy. A very promising targeted therapy is based on direct impact only on cancer cells. As a continuation of our research on new biologically active molecules, we report herein the design, synthesis and anticancer evaluation of a new series of N-Mannich-base-type hybrid compounds containing morfoline or different substituted piperazines moieties, a 1,3,4-oxadiazole ring and a 4,6-dimethylpyridine core. All compounds were tested for their potential cytotoxicity against five human cancer cell lines, A375, C32, SNB-19, MCF-7/WT and MCF-7/DX. Two of the active N-Mannich bases (compounds 5 and 6) were further evaluated for growth inhibition effects in melanoma (A375 and C32), and normal (HaCaT) cell lines using clonogenic assay and a population doubling time test. The apoptosis was determined with the neutral version of comet assay. The confocal microscopy method enabled the visualization of F-actin reorganization. The obtained results demonstrated that compounds 5 and 6 have cytotoxic and proapoptotic effects on melanoma cells and are capable of inducing F-actin depolarization in a dose-dependent manner. Moreover, computational chemistry approaches, molecular docking and electrostatic potential were employed to study non-covalent interactions of the investigated compounds with four receptors. It was found that all the examined molecules exhibit a similar binding affinity with respect to the chosen reference drugs.

Comprehensive review of α-carboline alkaloids: Natural products, updated synthesis, and biological activities

α-carboline (9H-pyrido[2,3-b]indole), contains a pyridine ring fused with an indole backbone, is a promising scaffold for medicinal chemistry. In recent decades, accumulating evidence shows that α-carboline natural products and their derivatives possess diverse bioactivities. However, hitherto, there is no comprehensive review to systematically summarize this important class of alkaloids. In this perspective, this paper represents the first review to provide a comprehensive description of α-carbolines including natural products, updated literature of synthesis, and their diverse biological activities. Their biological activities including antitumor, anti-microbial, anti-Alzheimer’s disease, anti-atherosclerosis, and antioxidant activities were hilighted. And the targets and the main structure activity relationships (SARs) will be presented. Finally, challenges and future directions of this class of compounds will be discussed. This review will be helpful in understanding and encouraging further exploration for this group of alkaloids.

Discovery of novel and potent tacrine derivatives as CDK2 inhibitors

After optimization of the lead compound, ZLHT-7, a compound with 10-fold higher selectivity for CDK2 over CDK9, was discovered.