Structure-Based Discovery of a Selective KDM5A Inhibitor that Exhibits Anti-Cancer Activity via Inducing Cell Cycle Arrest and Senescence in Breast Cancer Cell Lines

KDM5 family as therapeutic targets in breast cancer: Pathogenesis and therapeutic opportunities and challenges

Breast cancer (BC) is the most frequent malignant cancer diagnosis and is a primary factor for cancer deaths in women. The clinical subtypes of BC include estrogen receptor (ER) positive, progesterone receptor (PR) positive, human epidermal growth factor receptor 2 (HER2) positive, and triple-negative BC (TNBC). Based on the stages and subtypes of BC, various treatment methods are available with variations in the rates of progression-free disease and overall survival of patients. However, the treatment of BC still faces challenges, particularly in terms of drug resistance and recurrence. The study of epigenetics has provided new ideas for treating BC. Targeting aberrant epigenetic factors with inhibitors represents a promising anticancer strategy. The KDM5 family includes four members, KDM5A, KDM5B, KDM5C, and KDMD, all of which are Jumonji C domain-containing histone H3K4me2/3 demethylases. KDM5 proteins have been extensively studied in BC, where they are involved in suppressing or promoting BC depending on their specific upstream and downstream pathways. Several KDM5 inhibitors have shown potent BC inhibitory activity in vitro and in vivo, but challenges still exist in developing KDM5 inhibitors. In this review, we introduce the subtypes of BC and their current therapeutic options, summarize KDM5 family context-specific functions in the pathobiology of BC, and discuss the outlook and pitfalls of KDM5 inhibitors in this disease.

Histone Lysine Demethylase KDM5 Inhibitor CPI-455 Induces Astrocytogenesis in Neural Stem Cells

Lysine-specific histone demethylase 5A (KDM5A) is known to facilitate proliferation in cancer cells and maintain stemness to repress the astrocytic differentiation of neural stem cells (NSCs). In the study presented here, we investigated the effect of a KDM5 inhibitor, CPI-455, on NSC fate control. CPI-455 induced astrocytogenesis in NSCs during differentiation. Kdm5a, but not Kdm5c, knockdown induced glial fibrillary acidic protein (Gfap) transcription. CPI-455 induced signal transducer and activator of transcription 3, increased bone morphogenetic protein 2 expression, and enhanced mothers against decapentaplegic homolog 1/5/9 phosphorylation. The treatment of CPI-455 enhanced the methylation of histone H3 lysine 4 in the Gfap promoter when compared to that of the dimethyl sulfoxide control. In addition, CPI-455 treatment significantly reduced the recruitment of KDM5A to the Gfap promoter. Our data suggest that the KDM5 inhibitor CPI-455 effectively controls NSC cell fate via KDM5A inhibition and induces astrocytogenesis.

Curriculum vitae of CUG binding protein 1 (CELF1) in homeostasis and diseases: a systematic review

RNA-binding proteins (RBPs) are kinds of proteins with either singular or multiple RNA-binding domains (RBDs), and they can assembly into ribonucleic acid-protein complexes, which mediate transportation, editing, splicing, stabilization, translational efficiency, or epigenetic modifications of their binding RNA partners, and thereby modulate various physiological and pathological processes. CUG-BP, Elav-like family 1 (CELF1) is a member of the CELF family of RBPs with high affinity to the GU-rich elements in mRNA, and thus exerting control over critical processes including mRNA splicing, translation, and decay. Mounting studies support that CELF1 is correlated with occurrence, genesis and development and represents a potential therapeutical target for these malignant diseases. Herein, we present the structure and function of CELF1, outline its role and regulatory mechanisms in varieties of homeostasis and diseases, summarize the identified CELF1 regulators and their structure-activity relationships, and prospect the current challenges and their solutions during studies on CELF1 functions and corresponding drug discovery, which will facilitate the establishment of a targeted regulatory network for CELF1 in diseases and advance CELF1 as a potential drug target for disease therapy.

The emerging roles of lysine-specific demethylase 4A in cancer: Implications in tumorigenesis and therapeutic opportunities

Lysine-specific demethylase 4 A (KDM4A, also named JMJD2A, KIA0677, or JHDM3A) is a demethylase that can remove methyl groups from histones H3K9me2/3, H3K36me2/3, and H1.4K26me2/me3. Accumulating evidence suggests that KDM4A is not only involved in body homeostasis (such as cell proliferation, migration and differentiation, and tissue development) but also associated with multiple human diseases, especially cancers. Recently, an increasing number of studies have shown that pharmacological inhibition of KDM4A significantly attenuates tumor progression in vitro and in vivo in a range of solid tumors and acute myeloid leukemia. Although there are several reviews on the roles of the KDM4 subfamily in cancer development and therapy, all of them only briefly introduce the roles of KDM4A in cancer without systematically summarizing the specific mechanisms of KDM4A in various physiological and pathological processes, especially in tumorigenesis, which greatly limits advances in the understanding of the roles of KDM4A in a variety of cancers, discovering targeted selective KDM4A inhibitors, and exploring the adaptive profiles of KDM4A antagonists. Herein, we present the structure and functions of KDM4A, simply outline the functions of KDM4A in homeostasis and non-cancer diseases, summarize the role of KDM4A and its distinct target genes in the development of a variety of cancers, systematically classify KDM4A inhibitors, summarize the difficulties encountered in the research of KDM4A and the discovery of related drugs, and provide the corresponding solutions, which would contribute to understanding the recent research trends on KDM4A and advancing the progression of KDM4A as a drug target in cancer therapy.

Domain architecture and protein-protein interactions regulate KDM5A recruitment to the chromatin

Tri-methylation of Histone 3 lysine 4 (H3K4) is an important epigenetic modification whose deposition and removal can affect the chromatin at structural and functional levels. KDM5A is one of the four known H3K4-specific demethylases. It is a part of the KDM5 family, which is characterized by a catalytic Jumonji domain capable of removing H3K4 di- and tri-methylation marks. KDM5A has been found to be involved in multiple cellular processes such as differentiation, metabolism, cell cycle, and transcription. Its link to various diseases, including cancer, makes KDM5A an important target for drug development. However, despite several studies outlining its significance in various pathways, our lack of understanding of its recruitment and function at the target sites on the chromatin presents a challenge in creating effective and targeted treatments. Therefore, it is essential to understand the recruitment mechanism of KDM5A to chromatin, and its activity therein, to comprehend how various roles of KDM5A are regulated. In this review, we discuss how KDM5A functions in a context-dependent manner on the chromatin, either directly through its structural domain, or through various interacting partners, to bring about a diverse range of functions.

The role and prospect of lysine-specific demethylases in cancer chemoresistance

Histone methylation plays a key function in modulating gene expression, and preserving genome integrity and epigenetic inheritance. However, aberrations of histone methylation are commonly observed in human diseases, especially cancer. Lysine methylation mediated by histone methyltransferases can be reversed by lysine demethylases (KDMs), which remove methyl marks from histone lysine residues. Currently, drug resistance is a main impediment for cancer therapy. KDMs have been found to mediate drug tolerance of many cancers via altering the metabolic profile of cancer cells, upregulating the ratio of cancer stem cells and drug-tolerant genes, and promoting the epithelial-mesenchymal transition and metastatic ability. Moreover, different cancers show distinct oncogenic addictions for KDMs. The abnormal activation or overexpression of KDMs can alter gene expression signatures to enhance cell survival and drug resistance in cancer cells. In this review, we describe the structural features and functions of KDMs, the KDMs preferences of different cancers, and the mechanisms of drug resistance resulting from KDMs. We then survey KDM inhibitors that have been used for combating drug resistance in cancer, and discuss the opportunities and challenges of KDMs as therapeutic targets for cancer drug resistance.

Fbxo22 inhibits metastasis in triple-negative breast cancer through ubiquitin modification of KDM5A and regulation of H3K4me3 demethylation

The importance of Fbxo22 in carcinogenesis has been highly documented. Here, we discussed downstream regulatory factors of Fbxo22 in TNBC. RNA-sequencing was conducted for identifying differentially expressed genes, followed by construction of a regulatory network. Expression patterns of Fbxo22/KDM5A in TNBC were determined by their correlation with the prognosis analyzed. Then, regulation mechanisms between Fbxo22 and KDM5A as well as between KDM5A and H3K4me3 were assayed. After silencing and overexpression experiments, the significance of Fbxo22 in repressing tumorigenesis in vitro and in vivo was explored. Fbxo22 was poorly expressed, while KDM5A was highly expressed in TNBC. Patients with elevated Fbxo22, decreased KDM5A, or higher p16 had long overall survival. Fbxo22 reduced the levels of KDM5A by ubiquitination. KDM5A promoted histone H3K4me3 demethylation to downregulate p16 expression. Fbxo22 reduced KDM5A expression to enhance p16, thus inducing DNA damage as well as reducing tumorigenesis and metastasis in TNBC. Our study validated FBXO22 as a tumor suppressor in TNBC through ubiquitination of KDM5A and regulation of p16.

Involvement of AKT/PI3K Pathway in Sanguinarine's Induced Apoptosis and Cell Cycle Arrest in Triple-negative Breast Cancer Cells

BACKGROUND/AIM

Chemotherapy resistance in triple-negative breast cancer (TNBC) cells is well documented. Therefore, it is necessary to develop safer and more effective therapeutic agents to enhance the outcomes of chemotherapeutic agents. The natural alkaloid sanguinarine (SANG) has demonstrated therapeutic synergy when coupled with chemotherapeutic agents. SANG can also induce cell cycle arrest and trigger apoptosis in various cancer cells.

MATERIALS AND METHODS

In this study, we investigated the molecular mechanism underlying SANG activity in MDA-MB-231 and MDA-MB-468 cells as two genetically different models of TNBC. We employed various assays including Alamar Blue to measure the effect of SANG on cell viability and proliferation rate, flow cytometry analysis to study the potential of the compound to induce apoptosis and cell cycle arrest, quantitative qRT PCR apoptosis array to measure the expression of different genes mediating apoptosis, and the western system was used to analyze the impact of the compound on AKT protein expression.

RESULTS

SANG lowered cell viability and disrupted cell cycle progression in both cell lines. Furthermore, S-phase cell cycle arrest-mediated apoptosis was found to be the primary contributor to cell growth inhibition in MDA-MB-231 cells. SANG-treated TNBC cells showed significantly up-regulated mRNA expression of 18 genes associated with apoptosis, including eight TNF receptor superfamily (TNFRSF), three members of the BCL2 family, and two members of the caspase (CASP) family in MDA-MB-468 cells. In MDA-MB-231 cells, two members of the TNF superfamily and four members of the BCL2 family were affected. The western study data showed the inhibition of AKT protein expression in both cell lines concurrent with up-regulated BCL2L11 gene. Our results point to the AKT/PI3K signaling pathway as one of the key mechanisms behind SANG-induced cell cycle arrest and death.

CONCLUSION

SANG shows anticancer properties and apoptosis-related gene expression changes in the two TNBC cell lines and suggests AKT/PI3K pathway implication in apoptosis induction and cell cycle arrest. Thus, we propose SANG's potential as a solitary or supplementary treatment agent against TNBC.

HDAC inhibitors enhance the anti-tumor effect of immunotherapies in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most common liver malignancy with a poor prognosis and increasing incidence, remains a serious health problem worldwide. Immunotherapy has been described as one of the ideal ways to treat HCC and is transforming patient management. However, the occurrence of immunotherapy resistance still prevents some patients from benefiting from current immunotherapies. Recent studies have shown that histone deacetylase inhibitors (HDACis) can enhance the efficacy of immunotherapy in a variety of tumors, including HCC. In this review, we present current knowledge and recent advances in immunotherapy-based and HDACi-based therapies for HCC. We highlight the fundamental dynamics of synergies between immunotherapies and HDACis, further detailing current efforts to translate this knowledge into clinical benefits. In addition, we explored the possibility of nano-based drug delivery system (NDDS) as a novel strategy to enhance HCC treatment.

Mitochondria in cell senescence: A Friend or Foe?

Cell senescence denotes cell growth arrest in response to continuous replication or stresses damaging DNA or mitochondria. Mounting research suggests that cell senescence attributes to aging-associated failing organ function and diseases. Conversely, it participates in embryonic tissue maturation, wound healing, tissue regeneration, and tumor suppression. The acute or chronic properties and microenvironment may explain the double faces of senescence. Senescent cells display unique characteristics. In particular, its mitochondria become elongated with altered metabolomes and dynamics. Accordingly, mitochondria reform their function to produce more reactive oxygen species at the cost of low ATP production. Meanwhile, destructed mitochondrial unfolded protein responses further break the delicate proteostasis fostering mitochondrial dysfunction. Additionally, the release of mitochondrial damage-associated molecular patterns, mitochondrial Ca²⁺ overload, and altered NAD⁺ level intertwine other cellular organelle strengthening senescence. These findings further intrigue researchers to develop anti-senescence interventions. Applying mitochondrial-targeted antioxidants reduces cell senescence and mitigates aging by restoring mitochondrial function and attenuating oxidative stress. Metformin and caloric restriction also manifest senescent rescuing effects by increasing mitochondria efficiency and alleviating oxidative damage. On the other hand, Bcl2 family protein inhibitors eradicate senescent cells by inducing apoptosis to facilitate cancer chemotherapy. This review describes the different aspects of mitochondrial changes in senescence and highlights the recent progress of some anti-senescence strategies.

Histone Demethylase Modulation: Epigenetic Strategy to Combat Cancer Progression

Epigenetic modifications are heritable, reversible changes in histones or the DNA that control gene functions, being exogenous to the genomic sequence itself. Human diseases, particularly cancer, are frequently connected to epigenetic dysregulations. One of them is histone methylation, which is a dynamically reversible and synchronously regulated process that orchestrates the three-dimensional epigenome, nuclear processes of transcription, DNA repair, cell cycle, and epigenetic functions, by adding or removing methylation groups to histones. Over the past few years, reversible histone methylation has become recognized as a crucial regulatory mechanism for the epigenome. With the development of numerous medications that target epigenetic regulators, epigenome-targeted therapy has been used in the treatment of malignancies and has shown meaningful therapeutic potential in preclinical and clinical trials. The present review focuses on the recent advances in our knowledge on the role of histone demethylases in tumor development and modulation, in emphasizing molecular mechanisms that control cancer cell progression. Finally, we emphasize current developments in the advent of new molecular inhibitors that target histone demethylases to regulate cancer progression.

The role of lysine-specific demethylase 6A (KDM6A) in tumorigenesis and its therapeutic potentials in cancer therapy

Histone demethylation is a key post-translational modification of chromatin, and its dysregulation affects a wide array of nuclear activities including the maintenance of genome integrity, transcriptional regulation, and epigenetic inheritance. Lysine specific demethylase 6A (KDM6A, also known as UTX) is an Fe²⁺- and α-ketoglutarate- dependent oxidase which belongs to KDM6 Jumonji histone demethylase subfamily, and it can remove mono-, di- and tri-methyl groups from methylated lysine 27 of histone H3 (H3K27me1/2/3). Mounting studies indicate that KDM6A is responsible for driving multiple human diseases, particularly cancers and pharmacological inhibition of KDM6A is an effective strategy to treat varieties of KDM6A-amplified cancers in cellulo and in vivo. Although there are several reviews on the roles of KDM6 subfamily in cancer development and therapy, all of them only simply introduce the roles of KDM6A in cancer without systematically summarizing the specific mechanisms of KDM6A in tumorigenesis, which greatly limits the advances on the understanding of roles KDM6A in varieties of cancers, discovering targeting selective KDM6A inhibitors, and exploring the adaptive profiles of KDM6A antagonists. Herein, we present the structure and functions of KDM6A, simply outline the functions of KDM6A in homeostasis and non-cancer diseases, summarize the role of KDM6A and its distinct target genes/ligand proteins in development of varieties of cancers, systematically classify KDM6A inhibitors, sum up the difficulties encountered in the research of KDM6A and the discovery of related drugs, and provide the corresponding solutions, which will contribute to understanding the roles of KDM6A in carcinogenesis and advancing the progression of KDM6A as a drug target in cancer therapy.

Chemical Inhibitors Targeting the Histone Lysine Demethylase Families with Potential for Drug Discovery

The dynamic regulation of histone methylation and demethylation plays an important role in the regulation of gene expression. Aberrant expression of histone lysine demethylases has been implicated in various diseases including intractable cancers, and thus lysine demethylases serve as promising therapeutic targets. Recent studies in epigenomics and chemical biology have led to the development of a series of small-molecule demethylase inhibitors that are potent, specific, and have in vivo efficacy. In this review, we highlight emerging small-molecule inhibitors targeting the histone lysine demethylases and their progress toward drug discovery.

Targeting epigenetic regulators to overcome drug resistance in cancers

Drug resistance is mainly responsible for cancer recurrence and poor prognosis. Epigenetic regulation is a heritable change in gene expressions independent of nucleotide sequence changes. As the common epigenetic regulation mechanisms, DNA methylation, histone modification, and non-coding RNA regulation have been well studied. Increasing evidence has shown that aberrant epigenetic regulations contribute to tumor resistance. Therefore, targeting epigenetic regulators represents an effective strategy to reverse drug resistance. In this review, we mainly summarize the roles of epigenetic regulation in tumor resistance. In addition, as the essential factors for epigenetic modifications, histone demethylases mediate the histone or genomic DNA modifications. Herein, we comprehensively describe the functions of the histone demethylase family including the lysine-specific demethylase family, the Jumonji C-domain-containing demethylase family, and the histone arginine demethylase family, and fully discuss their regulatory mechanisms related to cancer drug resistance. In addition, therapeutic strategies, including small-molecule inhibitors and small interfering RNA targeting histone demethylases to overcome drug resistance, are also described.

Development of JmjC-domain-containing histone demethylase (KDM2-7) inhibitors for cancer therapy

Histone methylation is the most common histone modification and a highly dynamic regulator of gene transcription. Methylation of lysine residues can alter the structure of chromatin, helping to regulate DNA-based nuclear activities. Lysine demethylases control and maintain epigenetic factors that affect chromatin structure and cell characteristics. A variety of diseases, including malignant tumors, are connected to their dysregulation. Advances in biochemistry and pathogenesis have prompted the discovery of small molecule inhibitors and tool compounds that disrupt lysine demethylation. In this review, we focus on JmjC-domain-containing histone lysine demethylases (KDM2-7), discussing their structures and biological roles, representative inhibitors, and therapeutic potential in cancer therapy, and aiming to provide unique insights into the development of JmjC-KDM inhibitors.

Retinoblastoma-Binding Protein 5 Regulates H3K4 Methylation Modification to Inhibit the Proliferation of Melanoma Cells by Inactivating the Wnt/β-Catenin and Epithelial-Mesenchymal Transition Pathways

Histone 3 lysine 4 methylation (H3K4me), especially histone 3 lysine 4 trimethylation (H3K4me3), is one of the most extensively studied patterns of histone modification and plays crucial roles in many biological processes. However, as a part of H3K4 methyltransferase that participates in H3K4 methylation and transcriptional regulation, retinoblastoma-binding protein 5 (RBBP5) has not been well studied in melanoma. The present study sought to explore RBBP5-mediated H3K4 histone modification and the potential mechanisms in melanoma. RBBP5 expression in melanoma and nevi specimens was detected by immunohistochemistry. Western blotting was performed for three pairs of melanoma cancer tissues and nevi tissues. In vitro and in vivo assays were used to investigate the function of RBBP5. The molecular mechanism was determined using RT-qPCR, western blotting, ChIP assays, and Co-IP assays. Our study showed that RBBP5 was significantly downregulated in melanoma tissue and cells compared with nevi tissues and normal epithelia cells (P < 0.05). Reducing RBBP5 in human melanoma cells leads to H3K4me3 downregulation and promotes cell proliferation, migration, and invasion. On the one hand, we verified that WSB2 was an upstream gene of RBBP5-mediated H3K4 modification, which could directly bind to RBBP5 and negatively regulate its expression. On the other hand, we also confirmed that p16 (a cancer suppressor gene) was a downstream target of H3K4me3, the promoter of which can directly bind to H3K4me3. Mechanistically, our data revealed that RBBP5 inactivated the Wnt/β-catenin and epithelial-mesenchymal transition (EMT) pathways (P < 0.05), leading to melanoma suppression. Histone methylation is rising as an important factor affecting tumorigenicity and tumor progression. Our findings verified the significance of RBBP5-mediated H3K4 modification in melanoma and the potential regulatory mechanisms of melanoma proliferation and growth, suggesting that RBBP5 is a potential therapeutic target for the treatment of melanoma.

Intrinsic Apoptotic Pathway Genes of Circulating Blood Neutrophils Triggered during HIV Infection and Remained Stimulated in ART Patients

BACKGROUND

The intrinsic apoptotic pathway of neutrophils in Human Immunodeficiency Virus (HIV) infection results in spontaneous neutrophil death. There is a scarcity of data regarding the gene expression of an intrinsic apoptotic pathway of neutrophils in HIV patients.

OBJECTIVE

The objective of this study was to observe the differential expression of some important genes involved in the intrinsic apoptotic pathway of HIV patients, including those who were receiving antiretroviral therapy (ART).

METHODS

Blood samples were collected from asymptomatic, symptomatic, ART receiver HIV patients, and healthy individuals. Total RNA was extracted from neutrophils and subjected to quantitative real-time PCR assay. CD4+T cells and an automated complete blood count were performed.

RESULTS

Among the asymptomatic, symptomatic, and ART receiver HIV patients (n=20 in each group), median CD4+T counts were 633, 98, and 565 cells/ml, and the length of HIV infection in months (± SD) was 24.06 ± 21.36, 62.05 ± 25.51, and 69.2 ± 39.67, respectively. Compared with healthy controls, intrinsic apoptotic pathway genes, i.e., BAX, BIM, Caspase-3, Caspase-9, MCL-1, and Calpain-1, were upregulated to 1.21 ± 0.33, 1.8 ± 0.25, 1.24 ± 0.46, 1.54 ± 0.21, 1.88 ± 0.30, and 5.85 ± 1.34 fold in the asymptomatic group, and even more significantly, i.e., 1.51 ± 0.43, 2.09 ± 1.13, 1.85 ± 1.22, 1.72 ± 0.85, 2.26 ± 1.34, and 7.88 ± 3.31 fold in symptomatic patients, respectively. Despite CD4+ T-cell levels increased in the ART receiver group, these genes did not approach the level of healthy or asymptomatic and remained significantly upregulated.

CONCLUSION

The genes involved in the intrinsic apoptotic pathway in circulating neutrophils during HIV infection were stimulated in vivo, and ART reduced the expression of those upregulated genes but did not return to the level of asymptomatic or healthy individuals.

Dehydroeburicoic Acid, a Dual Inhibitor against Oxidative Stress in Alcoholic Liver Disease

Alcoholic liver disease (ALD) is a complicated disease which can lead to hepatocellular carcinoma; however, there is a lack of satisfactory therapeutics. Dehydroeburicoic acid (DEA) (1), a triterpenoid isolated from Antrodia cinnamomea, has been reported to act against ALD, but its mechanisms of action are still not clear. In this study, we report for the first time the use of DEA (1) as a dual inhibitor of the Keap1-Nrf2 protein-protein interaction (PPI) and GSK3β in an in vitro ALD cell model. DEA (1) engages Keap1 to disrupt the Keap1-Nrf2 PPI and inhibits GSK3β to restore Nrf2 activity in a Keap1-independent fashion. DEA (1) promotes Nrf2 nuclear translocation to activate downstream antioxidant genes. Importantly, DEA (1) restores the mitochondrial dysfunction induced by ethanol and generates antioxidant activity in the ALD cell model with minimal toxicity. We anticipate that DEA (1) could be a potential scaffold for the further development of clinical agents for treating ALD.

Drawing a line between histone demethylase KDM5A and KDM5B: their roles in development and tumorigenesis

Distinct epigenetic modifiers ensure coordinated control over genes that govern a myriad of cellular processes. Growing evidence shows that dynamic regulation of histone methylation is critical for almost all stages of development. Notably, the KDM5 subfamily of histone lysine-specific demethylases plays essential roles in the proper development and differentiation of tissues, and aberrant regulation of KDM5 proteins during development can lead to chronic developmental defects and even cancer. In this review, we adopt a unique perspective regarding the context-dependent roles of KDM5A and KDM5B in development and tumorigenesis. It is well known that these two proteins show a high degree of sequence homology, with overlapping functions. However, we provide deeper insights into their substrate specificity and distinctive function in gene regulation that at times divert from each other. We also highlight both the possibility of targeting KDM5A and KDM5B to improve cancer treatment and the limitations that must be overcome to increase the efficacy of current drugs.

Lysine demethylase 5A promotes prostate adenocarcinoma progression by suppressing microRNA-330-3p expression and activating the COPB2/PI3K/AKT axis in an ETS1-dependent manner

Lysine demethylase 5A (KDM5A) is a histone demethylase frequently involved in cancer progression. This research aimed to explore the function of KDM5A in prostate adenocarcinoma (PRAD) and the molecular mechanism. KDM5A was highly expressed in collected PRAD tissues and acquired PRAD cells. High KDM5A expression was correlated with reduced survival and poor prognosis of patients with PRAD. Knockdown of KDM5A suppressed the proliferation, colony formation, migration, and invasiveness of PRAD cells and reduced angiogenesis ability of endothelial cells. Downstream molecules implicated in KDM5A mediation were predicted using integrated bioinformatic analyses. KDM5A enhanced ETS proto-oncogene 1 (ETS1) expression through demethylation of H3K4me2 at its promoter. ETS1 suppressed the transcription activity of miR-330-3p, and either further ETS1 overexpression or miR-330-3p inhibition blocked the functions of KDM5A knockdown in PRAD. miR-330-3p targeted coatomer protein complex subunit β2 (COPB2) mRNA. Downregulation of miR-330-3p restored the expression of COPB2 and activated the PI3K/AKT pathway in PRAD. The results in vitro were reproduced in vivo where KDM5A downregulation suppressed the growth and metastasis of xenograft tumors in nude mice. In conclusion, this study demonstrated that KDM5A promoted PRAD by suppressing miR-330-3p and activating the COPB2/PI3K/AKT axis in an ETS1-dependent manner.

A state-of-the-art review on LSD1 and its inhibitors in breast cancer: Molecular mechanisms and therapeutic significance

Breast cancer (BC) is a kind of malignant cancer in women, and it has become the most diagnosed cancer worldwide since 2020. Histone methylation is a common biological epigenetic modification mediating varieties of physiological and pathological processes. Lysine-specific demethylase 1 (LSD1), a first identified histone demethylase, mediates the removal of methyl groups from histones H3K4me1/2 and H3K9me1/2 and plays a crucial role in varieties of cancer progression. It is also specifically amplified in breast cancer and contributes to BC tumorigenesis and drug resistance via both demethylase and non-demethylase manners. This review will provide insight into the overview structure of LSD1, summarize its action mechanisms in BC, describe the therapeutic potential of LSD1 inhibitors in BC, and prospect the current opportunities and challenges of targeting LSD1 for BC therapy.

Lysosome-targeted cyclometalated iridium(III) complexes: JMJD inhibition, dual induction of apoptosis and autophagy

A series of cyclometalated iridium(III) complexes with the formula [Ir(C^N)2 L](PF6) (C^N = 2-phenylpyridine (ppy, in Ir-1), 2-(2-thienyl)pyridine (thpy, in Ir-2), 2-(2,4-difluorophenyl)pyridine (dfppy, in Ir-3), L = 2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)quinolin-8-ol) were designed and synthesized, which utilize 8-hydroxyquinoline derivative as N^N ligands to chelate the cofactor Fe2+ of the Jumonji domain-containing protein (JMJD) histone demethylase. As expected, the results of UV/Vis titration analysis confirm the chelating capabilities of Ir-1-3 for Fe2+, and molecular docking studies also show that Ir-1-3 can interact with the active pocket of JMJD protein, and treatment of cells with Ir-1-3 results in significant upregulation of trimethylated histone 3 lysine 9 (H3K9Me3), indicating the inhibition of JMJD activity. Meanwhile, Ir-1-3 exhibit much higher cytotoxicity against the tested tumor cell lines compared with the clinical chemotherapeutic agent cisplatin. And Ir-1-3 can block the cell cycle at G2/M phase and inhibit cell migration and colony formation. Further studies show that Ir-1-3 can specifically accumulate in lysosomes, damage the integrity of lysosomes, and induce apoptosis and autophagy. Reduction of mitochondrial membrane potential (MMP) and elevation of reactive oxygen species (ROS) also contribute to the antitumor effects of Ir-1-3. Finally, Ir-1 can inhibit tumor growth effectively in vivo and increase the expression of H3K9Me3 in tumor tissues. Our study demonstrates that these iridium(III) complexes are promising anticancer agents with multiple functions, including the inhibition of JMJD and induction of apoptosis and autophagy.

Berberine as a potential agent for breast cancer therapy

Breast cancer (BC) is a common malignancy that mainly occurred in women and it has become the most diagnosed cancer annually since 2020. Berberine (BBR), an alkaloid extracted from the Berberidacea family, has been found with broad pharmacological bioactivities including anti-inflammatory, anti-diabetic, anti-hypertensive, anti-obesity, antidepressant, and anticancer effects. Mounting evidence shows that BBR is a safe and effective agent with good anticancer activity against BC. However, its detailed underlying mechanism in BC treatment remains unclear. Here, we will provide the evidence for BBR in BC therapy and summarize its potential mechanisms. This review briefly introduces the source, metabolism, and biological function of BBR and emphasizes the therapeutic effects of BBR against BC via directly interacting with effector proteins, transcriptional regulatory elements, miRNA, and several BBR-mediated signaling pathways. Moreover, the novel BBR-based therapeutic strategies against BC improve biocompatibility and water solubility, and the efficacies of BBR are also briefly discussed. Finally, the status of BBR in BC treatment and future research directions is also prospected.

JMJD family proteins in cancer and inflammation

The occurrence of cancer entails a series of genetic mutations that favor uncontrollable tumor growth. It is believed that various factors collectively contribute to cancer, and there is no one single explanation for tumorigenesis. Epigenetic changes such as the dysregulation of enzymes modifying DNA or histones are actively involved in oncogenesis and inflammatory response. The methylation of lysine residues on histone proteins represents a class of post-translational modifications. The human Jumonji C domain-containing (JMJD) protein family consists of more than 30 members. The JMJD proteins have long been identified with histone lysine demethylases (KDM) and histone arginine demethylases activities and thus could function as epigenetic modulators in physiological processes and diseases. Importantly, growing evidence has demonstrated the aberrant expression of JMJD proteins in cancer and inflammatory diseases, which might serve as an underlying mechanism for the initiation and progression of such diseases. Here, we discuss the role of key JMJD proteins in cancer and inflammation, including the intensively studied histone lysine demethylases, as well as the understudied group of JMJD members. In particular, we focused on epigenetic changes induced by each JMJD member and summarized recent research progress evaluating their therapeutic potential for the treatment of cancer and inflammatory diseases.

Targeting histone demethylases as a potential cancer therapy (Review)

Post‑translational modifications of histones by histone demethylases have an important role in the regulation of gene transcription and are implicated in cancers. Recently, the family of lysine (K)‑specific demethylase (KDM) proteins, referring to histone demethylases that dynamically regulate histone methylation, were indicated to be involved in various pathways related to cancer development. To date, numerous studies have been conducted to explore the effects of KDMs on cancer growth, metastasis and drug resistance, and a majority of KDMs have been indicated to be oncogenes in both leukemia and solid tumors. In addition, certain KDM inhibitors have been developed and have become the subject of clinical trials to explore their safety and efficacy in cancer therapy. However, most of them focus on hematopoietic malignancy. This review summarizes the effects of KDMs on tumor growth, drug resistance and the current status of KDM inhibitors in clinical trials.

KDM5A regulates the growth and gefitinib drug resistance against human lung adenocarcinoma cells

KDM5A, a histone demethylase, has been shown to be involved in several cancer-related process. The present study was undertaken to explore the role and therapeutic potential of KDM5A in human lung adenocarcinoma. The results of the qRT-PCR, immunohistochemistry, and western blotting showed significant upregulation of KDM5A expression in lung adenocarcinoma tissues and cell lines. The RNA interference-mediated silencing of KDM5A in lung adenocarcinoma cell line SK-LU-1 led to significant inhibition of in vitro cell proliferation via induction of apoptosis. The induction of apoptosis in SK-LU-1 lung adenocarcinoma cells was concomitant with upregulation of Bax and downregulation of Bcl-2 expression. In contrary, overexpression of KDM5A prompted the proliferation of SK-LU-1 lung adenocarcinoma cells. Interestingly, the SK-LU-1 cancer cells showed remarkably higher sensitivity to gefitinib under KDM5A transcriptional knockdown. Taken together, KDM5A is significantly upregulated in human lung adenocarcinoma and regulates the proliferation of the lung adenocarcinoma cells. These findings suggest potential of KDM5A to act as a therapeutic target for the management of human lung adenocarcinoma.

Epigenetic Factors as Etiological Agents, Diagnostic Markers, and Therapeutic Targets for Luminal Breast Cancer

Luminal breast cancer, an etiologically heterogeneous disease, is characterized by high steroid hormone receptor activity and aberrant gene expression profiles. Endocrine therapy and chemotherapy are promising therapeutic approaches to mitigate breast cancer proliferation and recurrence. However, the treatment of therapy-resistant breast cancer is a major challenge. Recent studies on breast cancer etiology have revealed the critical roles of epigenetic factors in luminal breast cancer tumorigenesis and drug resistance. Tumorigenic epigenetic factor-induced aberrant chromatin dynamics dysregulate the onset of gene expression and consequently promote tumorigenesis and metastasis. Epigenetic dysregulation, a type of somatic mutation, is a high-risk factor for breast cancer progression and therapy resistance. Therefore, epigenetic modulators alone or in combination with other therapies are potential therapeutic agents for breast cancer. Several clinical trials have analyzed the therapeutic efficacy of potential epi-drugs for breast cancer and reported beneficial clinical outcomes, including inhibition of tumor cell adhesion and invasiveness and mitigation of endocrine therapy resistance. This review focuses on recent findings on the mechanisms of epigenetic factors in the progression of luminal breast cancer. Additionally, recent findings on the potential of epigenetic factors as diagnostic biomarkers and therapeutic targets for breast cancer are discussed.

Epigenetic Modulators as Treatment Alternative to Diverse Types of Cancer

DNA is packaged in rolls in an octamer of histones forming a complex of DNA and proteins called chromatin. Chromatin as a structural matrix of a chromosome and its modifications are nowadays considered relevant aspects for regulating gene expression, which has become of high interest in understanding genetic mechanisms regulating various diseases, including cancer. In various types of cancer, the main modifications are found to be DNA methylation in the CpG dinucleotide as a silencing mechanism in transcription, post-translational histone modifications such as acetylation, methylation and others that affect the chromatin structure, the ATP-dependent chromatin remodeling and miRNA-mediated gene silencing. In this review we analyze the main alterations in gene expression, the epigenetic modification patterns that cancer cells present, as well as the main modulators and inhibitors of each epigenetic mechanism and the molecular evolution of the most representative inhibitors, which have opened a promising future in the study of HAT, HDAC, non-glycoside DNMT inhibitors and domain inhibitors.

Pharmacological inhibition of KDM5A for cancer treatment

Lysine-specific demethylase 5A (KDM5A, also named RBP2 or JARID1A) is a demethylase that can remove methyl groups from histones H3K4me1/2/3. It is aberrantly expressed in many cancers, where it impedes differentiation and contributes to cancer cell proliferation, cell metastasis and invasiveness, drug resistance, and is associated with poor prognosis. Pharmacological inhibition of KDM5A has been reported to significantly attenuate tumor progression in vitro and in vivo in a range of solid tumors and acute myeloid leukemia. This review will present the structural aspects of KDM5A, its role in carcinogenesis, a comparison of currently available approaches for screening KDM5A inhibitors, a classification of KDM5A inhibitors, and its potential as a drug target in cancer therapy.

Recent Progress of Small Molecule Menin-MLL Interaction Inhibitors as Therapeutic Agents for Acute Leukemia

Mixed lineage leukemia (MLL) gene rearrangements are associated with acute leukemia. The protein menin is regarded as a critical oncogenic cofactor of the resulting MLL fusion proteins in acute leukemia. A direct interaction between menin and the MLL amino terminal sequences is necessary for MLL fusion protein-mediated leukemogenesis. Thus, inhibition of the interaction between menin and MLL has emerged as a novel therapeutic strategy. Recent improvements in structural biology and chemical reactivity have promoted the design and development of selective and potent menin-MLL interaction inhibitors. In this Perspective, different classes of menin-MLL interaction inhibitors are comprehensively summarized. Further research potential, challenges, and opportunities in the field are also discussed.

A review on the emerging roles of pyruvate kinase M2 in anti-leukemia therapy

Glycolysis is an important step in respiration and provides energy for cellular processes. Pyruvate kinase M2 (PKM2), a key rate-limiting enzyme of glycolysis, plays an important role in tumor cell metabolism and proliferation. It is also specifically overexpressed in leukemia cells and contributes to leukemic proliferation, differentiation, and drug resistance through both aerobic glycolysis and non-metabolic pathways. In this review, the functions and regulatory roles of PKM2 are firstly introduced. Then, the molecular mechanisms of PKM2 in leukemogenesis are summarized. Next, reported PKM2 modulators and their anti-leukemia mechanisms are described. Finally, the current challenges and the potential opportunities of PKM2 inhibitors or agonists in leukemia therapy are discussed.

A computer aided drug discovery based discovery of lead-like compounds against KDM5A for cancers using pharmacophore modeling and high-throughput virtual screening

KDM5A over-expression mediates cancer cell proliferation and promotes resistance toward chemotherapy through epigenetic modifications. As its complete mechanism of action is still unknown, there is no KDM5A specific drug available at clinical level. In the current study, lead compounds for KDM5A were determined through pharmacophore modeling and high-throughput virtual screening from Asinex libraries containing 0.5 million compounds. These virtual hits were further evaluated and filtered for ADMET properties. Finally, 726 compounds were used for docking analysis against KDM5A. On the basis of docking score, 10 top-ranked compounds were selected and further evaluated for non-central nervous system (CNS) and CNS drug-like properties. Among these compounds, N-{[(7-Methyl-4-oxo-1,2,3,4-tetrahydrocyclopenta [c] chromen-9-yl) oxy]acetyl}-l-phenylalanine (G-score: -11.363 kcal/mol) was estimated to exhibit non-CNS properties while 2-(3,4-Dimethoxy-phenyl)-7-methoxy-chromen-4-one (G-score: -7.977 kcal/mol) was evaluated as CNS compound. Docked complexes of both compounds were finally selected for molecular dynamic simulation to examine the stability. This study concluded that both these compounds can serve as lead compounds in the quest of finding therapeutic agents against KDM5A associated cancers.

The Paradoxical Role of Cellular Senescence in Cancer

Cellular senescence occurs in proliferating cells as a consequence of various triggers including telomere shortening, DNA damage, and inappropriate expression of oncogenes. The senescent state is accompanied by failure to reenter the cell cycle under mitotic stimulation, resistance to cell death and enhanced secretory phenotype. A growing number of studies have convincingly demonstrated a paradoxical role for spontaneous senescence and therapy-induced senescence (TIS), that senescence may involve both cancer prevention and cancer aggressiveness. Cellular senescence was initially described as a physiological suppressor mechanism of tumor cells, because cancer development requires cell proliferation. However, there is growing evidence that senescent cells may contribute to oncogenesis, partly in a senescence-associated secretory phenotype (SASP)-dependent manner. On the one hand, SASP prevents cell division and promotes immune clearance of damaged cells, thereby avoiding tumor development. On the other hand, SASP contributes to tumor progression and relapse through creating an immunosuppressive environment. In this review, we performed a review to summarize both bright and dark sides of senescence in cancer, and the strategies to handle senescence in cancer therapy were also discussed.

An optimized BRD4 inhibitor effectively eliminates NF-κB-driven triple-negative breast cancer cells

Acetylation of NF-κB's RelA subunit at lysine-310 (AcLys310) helps to maintain constitutive NF-κB activity in cancers such as triple-negative breast cancer (TNBC). Bromodomain-containing factor BRD4 binds to acetylated RelA to promote the activity of NF-κB. Hence, interfering with the acetylated RelA-BRD4 interaction is a potential strategy for treating NF-κB-driven TNBC. Here, a new compound 13a was obtained by structural optimization and modification of our previously reported compound. In comparison with the well-known BRD4 inhibitor (+)-JQ1, 13a showed more potent anticancer activity in NF-κB-active MDA-MB-231 cells. Mechanistically, 13a antagonized the protein-protein interaction (PPI) between BRD4 and acetylated RelA, decreased levels of IL-6, IL-8, Snail, Vimentin, and ZEB1, induced cell senescence and DNA damage, and weakened the adhesion, metastasis, and invasion ability of TNBC cells. Our results provide insights into avenues for the further development of potent BRD4-acetylated RelA PPI inhibitors. Moreover, our findings highlight the effectiveness and feasibility of blocking the interaction between BRD4 and acetylated RelA against NF-κB-active cancers, and of screening antagonists of this PPI.

Targeting cancer epigenetic pathways with small-molecule compounds: Therapeutic efficacy and combination therapies

Epigenetics mainly refers to covalent modifications to DNA or histones without affecting genomes, which ultimately lead to phenotypic changes in cells or organisms. Given the abundance of regulatory targets in epigenetic pathways and their pivotal roles in tumorigenesis and drug resistance, the development of epigenetic drugs holds a great promise for the current cancer therapy. However, lack of potent, selective, and clinically tractable small-molecule compounds makes the strategy to target cancer epigenetic pathways still challenging. Therefore, this review focuses on epigenetic pathways, small molecule inhibitors targeting DNA methyltransferase (DNMT) and small molecule inhibitors targeting histone modification (the main regulatory targets are histone acetyltransferases (HAT), histone deacetylases (HDACs) and histone methyltransferases (HMTS)), as well as the combination strategies of the existing epigenetic therapeutic drugs and more new therapies to improve the efficacy, which will shed light on a new clue on discovery of more small-molecule drugs targeting cancer epigenetic pathways as promising strategies in the future.

Poly(ADP-ribose) binding and macroH2A mediate recruitment and functions of KDM5A at DNA lesions

The histone demethylase KDM5A erases histone H3 lysine 4 methylation, which is involved in transcription and DNA damage responses (DDRs). While DDR functions of KDM5A have been identified, how KDM5A recognizes DNA lesion sites within chromatin is unknown. Here, we identify two factors that act upstream of KDM5A to promote its association with DNA damage sites. We have identified a noncanonical poly(ADP-ribose) (PAR)–binding region unique to KDM5A. Loss of the PAR-binding region or treatment with PAR polymerase (PARP) inhibitors (PARPi’s) blocks KDM5A–PAR interactions and DNA repair functions of KDM5A. The histone variant macroH2A1.2 is also specifically required for KDM5A recruitment and function at DNA damage sites, including homology-directed repair of DNA double-strand breaks and repression of transcription at DNA breaks. Overall, this work reveals the importance of PAR binding and macroH2A1.2 in KDM5A recognition of DNA lesion sites that drive transcriptional and repair activities at DNA breaks within chromatin that are essential for maintaining genome integrity.

Histone lysine demethylases and their functions in cancer

Histone lysine demethylases (KDMs) are enzymes that remove the methylation marks on lysines in nucleosomes' histone tails. These changes in methylation marks regulate gene transcription during both development and malignant transformation. Depending on which lysine residue is targeted, the effect of a given KDM on gene transcription can be either activating or repressing, and KDMs can regulate the expression of both oncogenes and tumour suppressors. Thus, the functions of KDMs can be regarded as both oncogenic and tumour suppressive, contingent on cell context and the enzyme isoform. Finally, KDMs also demethylate nonhistone proteins and have a variety of demethylase-independent functions. These epigenetic and other mechanisms that KDMs control make them important regulators of malignant tumours. Here, we present an overview of eight KDM subfamilies, their most-studied lysine targets and selected recent data on their roles in cancer stem cells, tumour aggressiveness and drug tolerance.

Recent advances in biological activities of rhodium complexes: Their applications in drug discovery research

Unique structure, characteristic reactivity, and facile synthesis of metal complexes have made them efficient ligands in drug development research. Among them, rhodium complexes have a limited history and there are a few discussions about their biological activities documented in the literature. However, investigation of kinetically inert rhodium complexes has recently attracted lots of attention and especially there are various evidences on their anti-cancer activity. It seems that they can be investigated as a versatile surrogates or candidates for the existing drugs which do not affect selectively or suffer from various side effects. In recent years, there has been an increasing interest in the use of mononuclear rhodium (III) organometallo drugs due to its versatile structurally important aspects to inhibit various enzymes. It has been demonstrated that organometallic Rh complexes profiting from both organic and inorganic aspects have shown more potent biological activities than classical inorganic compartments. In this respect, smart design, use of the appropriate organic ligands, and efficient and user-friendly synthesis of organometallic Rh complexes have played crucial roles in the inducing desirable biological activities. In this review, we focused on the recent advances published on the bioactivity of Rh (III/II/I) complexes especially inhibitory activity, from 2013 till now. Accordingly, considering the structure-activity relationship (SAR), the effect of oxidation state (+1, +2, and +3) and geometry (dimer or monomer complexes with coordination number of 4 and 6) of Rh complexes as well as various ligands on in vitro and in vivo studies was comprehensively discussed.

The emerging role of KDM5A in human cancer

Histone methylation is a key posttranslational modification of chromatin, and its dysregulation affects a wide array of nuclear activities including the maintenance of genome integrity, transcriptional regulation, and epigenetic inheritance. Variations in the pattern of histone methylation influence both physiological and pathological events. Lysine-specific demethylase 5A (KDM5A, also known as JARID1A or RBP2) is a KDM5 Jumonji histone demethylase subfamily member that erases di- and tri-methyl groups from lysine 4 of histone H3. Emerging studies indicate that KDM5A is responsible for driving multiple human diseases, particularly cancers. In this review, we summarize the roles of KDM5A in human cancers, survey the field of KDM5A inhibitors including their anticancer activity and modes of action, and the current challenges and potential opportunities of this field.

Long non-coding RNAs in lung cancer: implications for lineage plasticity-mediated TKI resistance

The efficacy of targeted therapy in non-small-cell lung cancer (NSCLC) has been impeded by various mechanisms of resistance. Besides the mutations in targeted oncogenes, reversible lineage plasticity has recently considered to play a role in the development of tyrosine kinase inhibitors (TKI) resistance in NSCLC. Lineage plasticity enables cells to transfer from one committed developmental pathway to another, and has been a trigger of tumor adaptation to adverse microenvironment conditions including exposure to various therapies. More importantly, besides somatic mutation, lineage plasticity has also been proposed as another source of intratumoural heterogeneity. Lineage plasticity can drive NSCLC cells to a new cell identity which no longer depends on the drug-targeted pathway. Histological transformation and epithelial–mesenchymal transition are two well-known pathways of lineage plasticity-mediated TKI resistance in NSCLC. In the last decade, increased re-biopsy practice upon disease recurrence has increased the recognition of lineage plasticity induced resistance in NSCLC and has improved our understanding of the underlying biology. Long non-coding RNAs (lncRNAs), the dark matter of the genome, are capable of regulating variant malignant processes of NSCLC like the invisible hands. Recent evidence suggests that lncRNAs are involved in TKI resistance in NSCLC, particularly in lineage plasticity-mediated resistance. In this review, we summarize the mechanisms of lncRNAs in regulating lineage plasticity and TKI resistance in NSCLC. We also discuss how understanding these themes can alter therapeutic strategies, including combination therapy approaches to overcome TKI resistance.

Telomere dysfunction cooperates with epigenetic alterations to impair murine embryonic stem cell fate commitment

The precise relationship between epigenetic alterations and telomere dysfunction is still an extant question. Previously, we showed that eroded telomeres lead to differentiation instability in murine embryonic stem cells (mESCs) via DNA hypomethylation at pluripotency-factor promoters. Here, we uncovered that telomerase reverse transcriptase null (Tert^-/-) mESCs exhibit genome-wide alterations in chromatin accessibility and gene expression during differentiation. These changes were accompanied by an increase of H3K27me3 globally, an altered chromatin landscape at the Pou5f1/Oct4 promoter, and a refractory response to differentiation cues. Inhibition of the Polycomb Repressive Complex 2 (PRC2), an H3K27 tri-methyltransferase, exacerbated the impairment in differentiation and pluripotency gene repression in Tert^-/-mESCs but not wild-type mESCs, whereas inhibition of H3K27me3 demethylation led to a partial rescue of the Tert^-/- phenotype. These data reveal a new interdependent relationship between H3K27me3 and telomere integrity in stem cell lineage commitment that may have implications in aging and cancer.

2,4-Dichlorophenoxyacetic Thiosemicarbazides as a New Class of Compounds Against Stomach Cancer Potentially Intercalating with DNA

Thiosemicarbazide is a useful structural moiety that has the biological potential. Optimization of this structure can result in groundbreaking discovery of a new class of therapeutic agents. In the light of this, 1-(2,4-dichlorophenoxy)acetyl-4-(1-naphthyl)thiosemicarbazide (1) and 1,4-bis[(2,4-dichlorophenoxy)acetylthiosemicarbazide]phenyl (2) were synthesized and characterized by spectroscopic method. Cytotoxicity of obtained compounds was evaluated on MKN74 gastric cancer cell line and human skin fibroblast BJ based on methylthiazolyldiphenyl-tetrazolium bromide (MTT) test. The apoptosis/necrosis and cell cycle analysis were conducted using image cytometry. Additionally, in DNA of treated cells, abasic sites (AP) and double strands breaks (DSB) presence were measured. Intercalating properties of active compounds were evaluated using the UV–spectroscopic method. Among newly synthesized derivatives, compound 2 showed toxic effects on gastric cancer cells with simultaneous lack of toxicity to normal fibroblasts. Cell cycle analysis revealed that both compounds influence cell division mainly at the stage of replication. Simultaneously with DNA synthesis disorders, DNA damages like AP-sites and DSBs were observed. Spectroscopic studies revealed possible DNA intercalating properties of tested compounds. Obtained results indicate that the newly synthesized thiosemicarbazide derivatives are a promising group of compounds with potential anticancer activity resulted from interactions with DNA and cell cycle interrupt.

Mimicking Strategy for Protein-Protein Interaction Inhibitor Discovery by Virtual Screening

As protein–protein interactions (PPIs) are highly involved in most cellular processes, the discovery of PPI inhibitors that mimic the structure of the natural protein partners is a promising strategy toward the discovery of PPI inhibitors. In this review, we discuss recent advances in the application of virtual screening for identifying mimics of protein partners. The classification and function of the mimicking protein partner inhibitor discovery by virtual screening are described. We anticipate that this review would be of interest to medicinal chemists and chemical biologists working in the field of protein–protein interaction inhibitors or probes.

NEK2 promotes proliferation, migration and tumor growth of gastric cancer cells via regulating KDM5B/H3K4me3

The mechanisms of how Never in Mitosis (NIMA) Related Kinase 2 (NEK2) coordinates altered signaling to malignant gastric cancer (GC) transformation remain unclear. Overexpression of NEK2 and KDM5B were observed in GC cell lines with high sensitivity to NEK2 inhibitors. Here we investigated the biological behaviors of NEK2 and the possible mechanisms of regulative effects of NEK2 on KDM5B in GC cell lines both in vitro and in vivo. The results showed that NEK2 and KDM5B were highly expressed in most of the 10 GC cell lines. NEK2 knockdown in MGC-803 cells led to suppression of cell proliferation and migration in vitro and tumor growth in vivo, while NEK2 overexpression in BGC-823 cells exhibited the reverse biological effect. When NEK2 was inhibited by NEK2 inhibitors or shNEK2, cellular KDM5B level decreased and H3K4me3 level increased, while overexpression of NEK2 resulted in enhanced KDM5B expression and decreased H3K4me3 level. Though direct interaction between NEK2 and KDM5B was excluded, NEK2 could regulate KDM5B/H3K4me3 expression through β-catenin/Myc both in vitro and in vivo, which was double confirmed by c-myc and KDM5B inhibitor experiments. Taken together, our study showed that NEK2 was highly expressed in GC cell lines and related to promoting cell proliferation, migration and tumor growth. A NEK2/β-catenin/Myc/KDM5B/H3K4me3 signaling pathway may contribute to the important carcinogenic role of NEK2-mediated malignant behaviors in GC.

Rebalancing metal dyshomeostasis for Alzheimer's disease therapy

Alzheimer's disease (AD) is a type of neurodegenerative malady that is associated with the accumulation of amyloid plaques. Metal ions are critical for the development and upkeep of brain activity, but metal dyshomeostasis can contribute to the development of neurodegenerative diseases, including AD. This review highlights the association between metal dyshomeostasis and AD pathology, the feasibility of rebalancing metal homeostasis as a therapeutic strategy for AD, and a survey of current drugs that action via rebalancing metal homeostasis. Finally, we discuss the challenges that should be overcome by researchers in the future to enable the practical use of metal homeostasis rebalancing agents for clinical application.

Epigenetic Dysregulation at the Crossroad of Women's Cancer

An increasingly number of women of all age groups are affected by cancer, despite substantial progress in our understanding of cancer pathobiology, the underlying genomic alterations and signaling cascades, and cellular-environmental interactions. Though our understanding of women’s cancer is far more complete than ever before, there is no comprehensive model to explain the reasons behind the increased incidents of certain reproductive cancer among older as well as younger women. It is generally suspected that environmental and life-style factors affecting hormonal and growth control pathways might help account for the rise of women’s cancers in younger age, as well, via epigenetic mechanisms. Epigenetic regulators play an important role in orchestrating an orderly coordination of cellular signals in gene activity in response to upstream signaling and/or epigenetic modifiers present in a dynamic extracellular milieu. Here we will discuss the broad principles of epigenetic regulation of DNA methylation and demethylation, histone acetylation and deacetylation, and RNA methylation in women’s cancers in the context of gene expression, hormonal action, and the EGFR family of cell surface receptor tyrosine kinases. We anticipate that a better understanding of the epigenetics of women’s cancers may provide new regulatory leads and further fuel the development of new epigenetic biomarkers and therapeutic approaches.