Inhibition of histone deacetylases attenuates tumor progression and improves immunotherapy in breast cancer

pH-responsive nano-vaccine combined with anti-PD-1 antibodies for enhanced immunotherapy of breast cancer

Objective: This study aimed to investigate the therapeutic potential and underlying mechanisms of a novel pH-responsive nano-vaccine in combination with anti-Programmed Cell Death Protein 1 (PD-1) antibodies for the treatment of breast cancer (BC), with a focus on tumor growth inhibition, metastasis prevention, and immune microenvironment modulation. Methods: A pH-responsive amphiphilic diblock copolymer was synthesized using reversible addition-fragmentation chain transfer (RAFT) polymerization and conjugated with STING agonist ADU-S100 and mannose to specifically target dendritic cells (DCs). The nano-vaccine was further formulated with antigen peptides and polyethyleneimine (PEI) to enhance antigen delivery. Its particle size, stability, and surface charge were characterized using dynamic light scattering (DLS) and zeta potential analysis. In vitro, the immunostimulatory capacity of the nano-vaccine was evaluated via flow cytometry (FCM) analysis of DC activation markers. In vivo, mouse immune and tumor recurrence models were used to assess the its effects on T-cell activation, tumor suppression, and immune memory induction. The therapeutic efficacy of nano-vaccine/anti-PD-1 combination therapy was further assessed. Results: The nano-vaccine efficiently activated DCs and promoted antigen presentation, as indicated by increased CD80, CD86, and MHC-II expression in vitro. In mouse models, it effectively inhibited tumor growth, induced antigen-specific T-cell responses, and suppressed recurrent and metastatic tumor progression. The combination with anti-PD-1 antibodies further enhanced tumor control, immune cell infiltration, and survival rates compared to monotherapy. Conclusion: The pH-responsive nano-vaccine combined with anti-PD-1 antibodies showed remarkable synergistic effects in BC treatment, highlighting its potential to enhance immune checkpoint blockade therapy and offer a promising strategy for clinical applications in solid tumors.

Identification and evaluation of Pharmacological enhancers of the factor VII p.Q160R variant

Congenital factor (F) VII deficiency is caused by mutations in the F7 gene. The p.Q160R variant manifests with bleeding episodes due to reduced FVII activity and antigen in patient plasma, most likely caused by protein misfolding and intracellular retention. As current replacement therapy is expensive and requires frequent intravenous injections, there is an unmet need for new and less invasive therapeutic strategies. Drug repurposing allows for rapid, more cost-effective discovery and implementation of new treatments, and identification of pharmacological enhancers of FVII variant activity would be of clinical importance. High-throughput screening of > 1800 FDA-approved drugs identified the orally available histone deacetylase inhibitor abexinostat and the inhaled surfactant tyloxapol as enhancers of FVII p.Q160R variant activity. The positive hits were verified in an in vitro cell model transiently expressing wild type or variant FVII and ex vivo in patients' plasma. Both drugs showed a dose-response effect on FVII antigen and activity levels in conditioned cell medium and on FVII activity in patients' plasma. In conclusion, the efficacy of the FDA-approved drugs abexinostat and tyloxapol in enhancing FVII variant activity constitute a proof of principle for high-throughput identification of drugs that may be feasible for novel treatment of FVII deficiency.

Harnessing lysosomal genetics: development of a risk stratification panel and unveiling of DPP7 as a biomarker for colon adenocarcinoma

Lysosomal dysfunction has been implicated in the progression of colon adenocarcinoma (COAD), yet the prognostic significance and therapeutic potential of lysosome-related genes (LRGs) remain underexplored. In this study, we construct a 6-LRG-based prognostic risk stratification model (DPP7, ADAM8, CD1B, LRP2, ATP6V1C2, and PLAAT3) by integrating LASSO and Cox regression analyses. Stratifying patients based on median risk scores, we demonstrate that high-risk patients exhibit significantly worse clinical outcomes across the TCGA cohort and five independent GEO datasets. Furthermore, this panel outperforms 136 previously published models in terms of predictive accuracy for 1-, 3-, and 5-year survival rates. Validation multiplex immunofluorescence using an in-house tissue microarray cohort confirms the 6-LRG signature serves as an independent prognostic factor. Additionally, high-risk patients exhibit distinct immunosuppressive tumor microenvironment and aggressive malignancy characteristics. Functional depletion of DPP7 significantly inhibits tumor cell proliferation, migration, and metastasis in both in vitro and in vivo settings. Moreover, DPP7 silencing attenuates epithelial-mesenchymal transition, as evidenced by the upregulation of E-cadherin and downregulation of N-cadherin, Vimentin, and Snail. In conclusion, this study establishes an LRG-based model for COAD prognostic prediction and nominates DPP7 as a promising therapeutic target for COAD treatment.

A promising future for breast cancer therapy with hydroxamic acid-based histone deacetylase inhibitors

Histone deacetylases (HDACs) play a critical role in chromatin remodelling and modulating the activity of various histone proteins. Aberrant HDAC functions has been related to the progression of breast cancer (BC), making HDAC inhibitors (HDACi) promising small-molecule therapeutics for its treatment. Hydroxamic acid (HA) is a significant pharmacophore due to its strong metal-chelating ability, HDAC inhibition properties, MMP inhibition abilities, and more. They were found to increase the efficacy of the approved drugs when used in combination. In this review we presented bioinformatic analysis using available data from the Cancer Genome Atlas and Genotype-Tissue Expression databases, outlined the recent advancements in the application of HA-based HDACi for BC during preclinical investigation and clinical trials, tried to offer the rationale for targeting HDAC in BC with HA-based HDACi, summarised the challenges faced in the successful clinical application of HDACi, and proposed potential strategies to address these challenges, aiming to enhance treatment outcomes in BC. Abbreviations: ABCG2, ATP-binding cassette super-family G member 2; ABC, ATP-binding cassette; ADP, Adenosine diphosphate; APC, Antigen presenting cell; AML, Acute myeloid leukemia; ARH1, Aplysia ras homolog 1; BCRP, Breast cancer resistance protein; BRCA, Breast invasive carcinoma; Bax, B-cell lymphoma associated X; CK5, Cytokeratin 5; CK14, Cytokeratin 14; CK17, Cytokeratin 17; CoRESTMiDAC, Co-repressor for element-1-silencing transcription factor; CRM1, Chromosomal maintenance 1; CTCL, Cutaneous T-cell lymphoma; DNMT, DNA methyltransferase; DFS, Disease-free survival; ER, Oestrogen receptor; EMT, Epithelial-mesenchymal transition; FGFR1, Fibroblast growth factor receptor 1; GEPIA, Gene Expression Profiling Interactive Analysis; GTEx, Genotype tissue expression; HAT, Histone acetylase; HDAC, Histone deacetylase; HDF, Human dermal fibroblast; HER2, Human epidermal growth factor receptor 2; HDLP, Histone deacetylase-like protein; Hsp90, Heat shock protein 90; HSF1, Heat shock factor 1; HeLa, Henrietta Lacks; HER1, Human epidermal growth factor receptor 1; IARC, International Agency for Research on Cancer; IL-10, Interleukin-10; KAP1, KRAB associated protein 1; MDM2, Mouse double minute 2 homolog; MDR, Multidrug resistance; MCF-7, Michigan cancer foundation-7; MEF-2, Myocyte enhancer factor-2MMP- Matrix metalloproteinase; NAD, Nicotinamide adenine dinucleotide; NuRD, Nucleosome remodelling and deacetylation; NF- κ B, Nuclear factor kappa light chain enhancer of activated B cell; NES, Nuclear export signal; NLS, Nuclear localization signal; NCoR, Nuclear receptor corepressor; NCT, National clinical trial; OS, Overall survival; PR, Progesterone receptor; PI3K, Phosphoinositide 3-kinase; PAX3, Paired box gene 3; P-gp, P-glycoprotein; ROS, Reactive oxygen species; SIRT, Sirtuin; SMRT, Silencing mediator for retinoid and thyroid receptor; STAT3, Signal transducer and activator of transcription-3; SAR, Structure-activity relationship; SHP1, Src homology region 2 domain-containing phosphatase 1; SAHA, Suberoylanilide hydroxamic acid; SMEDDS, Self micro emulsifying drug delivery system; TNBC, Triple-negative breast cancer; TSA, Trichostatin A; ZBG, Zinc binding group.

At the nucleus of cancer: how the nuclear envelope controls tumor progression

Historically considered downstream effects of tumorigenesis-arising from changes in DNA content or chromatin organization-nuclear alterations have long been seen as mere prognostic markers within a genome-centric model of cancer. However, recent findings have placed the nuclear envelope (NE) at the forefront of tumor progression, highlighting its active role in mediating cellular responses to mechanical forces. Despite significant progress, the precise interplay between NE components and cancer progression remains under debate. In this review, we provide a comprehensive and up-to-date overview of how changes in NE composition affect nuclear mechanics and facilitate malignant transformation, grounded in the latest molecular and functional studies. We also review recent research that uses advanced technologies, including artificial intelligence, to predict malignancy risk and treatment outcomes by analyzing nuclear morphology. Finally, we discuss how progress in understanding nuclear mechanics has paved the way for mechanotherapy-a promising cancer treatment approach that exploits the mechanical differences between cancerous and healthy cells. Shifting the perspective on NE alterations from mere diagnostic markers to potential therapeutic targets, this review calls for further investigation into the evolving role of the NE in cancer, highlighting the potential for innovative strategies to transform conventional cancer therapies.

Innovative Approaches for Molecular Targeted Therapy of Breast Cancer: Interfering with Various Pathway Signaling

Breast cancer encompasses a diverse array of conditions classified as hormone receptor-positive, human epidermal growth factor receptor 2-positive, and triple-negative breast cancer subtypes, dictating treatment approaches. The therapeutic strategies commonly involve addressing estrogen receptors (ER) and HER2, which have exhibited efficacy in managing cancer. Nevertheless, the prevalence of resistance to these therapies, whether inherent or acquired, persists despite the introduction of novel treatment modalities. Progress in comprehending the biology of tumors has facilitated the identification of fresh targets, such as inhibitors targeting different pathways like phosphoinositide 3-kinase/mammalian target of rapamycin (PI3K/mTOR), cell-cycle regulation, heat shock protein, and epigenetic pathways, demonstrating encouraging outcomes in clinical experiments. For example, the mTOR inhibitor everolimus has been sanctioned for ER+ breast cancer and resistance to aromatase inhibitors in the advanced or metastatic phase. Triple-negative breast cancer, characterized by the absence of estrogen receptors, progesterone receptors, and HER2, currently lacks established targeted therapies. While poly (ADP-ribose) polymerase inhibitors exhibit effectiveness in BRCA-related cancers, their efficiency in addressing triple-negative breast cancer residues is uncertain. This paper furnishes a comprehensive outline of the principal targeted therapies presently employed or under exploration for breast cancer treatment within the three clinical subsets.

Lysine deacetylase inhibitors have low selectivity in cells and exhibit predominantly off-target effects

Lysine deacetylases (KDACs or HDACs) are metal-dependent enzymes that regulate lysine acetylation, a post-translational modification that is present on thousands of human proteins, essential for many cellular processes, and often misregulated in diseases. The selective inhibition of KDACs would allow for understanding of the biological roles of individual KDACs and therapeutic targeting of individual enzymes. Recent studies have suggested that purportedly specific KDAC inhibitors have significant off-target binding, but the biological consequences of off-target binding were not evaluated. We compared the effects of treatment with two of the reportedly most KDAC-selective inhibitors, Tubastatin A and PCI-34051, in HT1080 cells in which the endogenous KDAC6 or KDAC8 gene has been mutated to inactivate enzyme catalysis while retaining enzyme expression. Genetic inactivation results in much stronger deacetylation defects on known targets compared to inhibitor treatment. Gene expression analysis revealed that both inhibitors have extensive and extensively overlapping off-target effects in cells, even at low inhibitor doses. Furthermore, Tubastatin A treatment led to increased histone acetylation, while inactivation of KDAC6 or KDAC8 did not. Genetic inactivation of KDAC6, but not KDAC8, impaired tumor formation in a xenograft model system, in contrast to previous reports with KDAC inhibitors suggesting the reverse. We conclude that the majority of observed biological effects of treatment with KDAC inhibitors are due to off-target effects rather than the intended KDAC inhibition. Developing a truly specific KDAC6 inhibitor could be a promising therapeutic avenue, but it is imperative to develop new inhibitors that selectively mimic genetic inactivation of individual KDACs.

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.

Design and optimization of novel Tetrahydro-β-carboline-based HDAC inhibitors with potent activities against tumor cell growth and metastasis

Histone deacetylases (HDACs) are validated drug targets for various therapeutic applications. A series of Tetrahydro-β-carboline-based hydroxamate derivatives, designed as HDAC inhibitors (HDACis), were synthesized. Compound 11g exhibited strong inhibitory activity against HDAC1 and the A549 cancer cell line. Additionally, this compound increased the levels of acetylated histone H3 and H4. Notably, 11g effectively arrested A549 cells in the G2/M phase and also increased ROS production and DNA damage, thereby inducing apoptosis. Further molecular docking experiments illustrated the potential interactions between compound 11g and HDAC1. These findings suggested that the novel Tetrahydro-β-carboline-based HDACis could serve as a promising framework for further optimization as anticancer agents.

Mannose-6-Phosphate Isomerase Functional Status Shapes a Rearrangement in the Proteome and Degradome of Mannose-Treated Melanoma Cells

Metabolic reprogramming is a ubiquitous feature of transformed cells, comprising one of the hallmarks of cancer and enabling neoplastic cells to adapt to new environments. Accumulated evidence reports on the failure of some neoplastic cells to convert mannose-6-phosphate into fructose-6-phosphate, thereby impairing tumor growth in cells displaying low levels of mannose-6-phosphate isomerase (MPI). Thus, we performed functional analyses and profiled the proteome landscape and the repertoire of substrates of proteases (degradome) of melanoma cell lines with distinct mutational backgrounds submitted to treatment with mannose. Our results suggest a significant rearrangement in the proteome and degradome of melanoma cell lines upon mannose treatment including the activation of catabolic pathways (such as protein turnover) and differences in protein N-terminal acetylation. Even though MPI protein abundance and gene expression status are not prognostic markers, perturbation in the network caused by an exogenous monosaccharide source (i.e., mannose) significantly affected the downstream interconnected biological circuitry. Therefore, as reported in this study, the proteomic/degradomic mapping of mannose downstream effects due to the metabolic rewiring caused by the functional status of the MPI enzyme could lead to the identification of specific molecular players from affected signaling circuits in melanoma.

Impact of HDAC inhibitors on macrophage polarization to enhance innate immunity against infections

Innate immunity plays an important role in host defense against pathogenic infections. It involves macrophage polarization into either the pro-inflammatory M1 or the anti-inflammatory M2 phenotype, influencing immune stimulation or suppression, respectively. Epigenetic changes during immune reactions contribute to long-term innate immunity imprinting on macrophage polarization. It is becoming increasingly evident that epigenetic modulators, such as histone deacetylase (HDAC) inhibitors (HDACi), enable the enhancement of innate immunity by tailoring macrophage polarization in response to immune stressors. In this review, we summarize current literature on the impact of HDACi and other epigenetic modulators on the functioning of macrophages during diseases that have a strong immune component, such as infections. Depending on the disease context and the chosen therapeutic intervention, HDAC1, HDAC2, HDAC3, HDAC6, or HDAC8 are particularly important in influencing macrophage polarization towards either M1 or M2 phenotypes. We anticipate that therapeutic strategies based on HDAC epigenetic mechanisms will provide a unique approach to boost immunity against disease challenges, including resistant infections.

From Biosensors to Robotics: Pioneering Advances in Breast Cancer Management

Breast cancer stands as the most prevalent form of cancer amongst females, constituting more than one-third of all cancer cases affecting women. It causes aberrant cell development, which can assault or spread to other sections of the body, perhaps leading to the patient's death. Based on research findings, timely detection can diminish the likelihood of mortality and enhance the quality of healthcare provided for the illness. However, current technologies can only identify cancer at an advanced stage. Consequently, there is a substantial demand for rapid and productive approaches to detecting breast cancer. Researchers are actively pursuing precise and timely methods for the diagnosis of breast cancer, aiming to achieve enhanced accuracy and early detection. Biosensor technology can allow for the speedy and accurate diagnosis of cancer-related cells, as well as a more sensitive and specialized technique for generating them. Additionally, numerous treatments for breast cancer are depicted such as herbal therapy, nanomaterial-based drug delivery, miRNA targeting, CRISPR technology, immunotherapy, and precision medicine. Early detection and efficient therapy are necessary to manage such a severe illness properly.

TSA attenuates the progression of c-Myc-driven hepatocarcinogenesis by pAKT-ADH4 pathway

Hepatocellular carcinoma (HCC) is the primary malignant tumor of the liver. c-Myc is one of the most common oncogenes in clinical settings, and amplified levels of c-Myc are frequently found in HCC. Histone deacetylase inhibitors (HDACi), such as Trichostatin A (TSA), hold enormous promise for the treatment of HCC. However, the potential and mechanism of TSA in the treatment of c-Myc-induced HCC are unclear. In this study, we investigated the effects of TSA treatment on a c-Myc-induced HCC model in mice. TSA treatment delayed the development of HCC, and liver function indicators such as ALT, AST, liver weight ratio, and spleen weight ratio demonstrated the effectiveness of TSA treatment. Oil red staining further demonstrated that TSA attenuated lipid accumulation in the HCC tissues of mice. Through mRNA sequencing, we identified that TSA mainly affected cell cycle and fatty acid degradation genes, with alcohol dehydrogenase 4 (ADH4) potentially being the core molecular downstream target. QPCR, immunohistochemistry, and western blot analysis revealed that ADH4 expression was repressed by c-Myc and restored after TSA treatment both in vitro and in vivo. Furthermore, we observed that the levels of total NAD+ and NADH, NAD+, NAD+/NADH, and ATP concentration increased after c-Myc transfection in liver cells but decreased after TSA intervention. The levels of phosphorylated protein kinase B (p-AKT) and p-mTOR were identified as targets regulated by TSA, and they governed the ADH4 expression and the downstream regulation of total NAD+ and NADH, NAD+, NAD+/NADH, and ATP concentration. Overall, our study suggests that TSA has a therapeutic effect on c-Myc-induced HCC through the AKT-mTOR-ADH4 pathway. These findings provide valuable insights into the potential treatment of HCC using TSA and shed light on the underlying molecular mechanisms involved.

Crosstalk between SUMOylation and other post-translational modifications in breast cancer

Breast cancer represents the most prevalent tumor type and a foremost cause of mortality among women globally. The complex pathophysiological processes of breast cancer tumorigenesis and progression are regulated by protein post-translational modifications (PTMs), which are triggered by different carcinogenic factors and signaling pathways, with small ubiquitin-like modifier (SUMOylation) emerging as a particularly pivotal player in this context. Recent studies have demonstrated that SUMOylation does not act alone, but interacts with other PTMs, such as phosphorylation, ubiquitination, acetylation, and methylation, thereby leading to the regulation of various pathological activities in breast cancer. This review explores novel and existing mechanisms of crosstalk between SUMOylation and other PTMs. Typically, SUMOylation is regulated by phosphorylation to exert feedback control, while also modulates subsequent ubiquitination, acetylation, or methylation. The crosstalk pairs in promoting or inhibiting breast cancer are protein-specific and site-specific. In mechanism, alterations in amino acid side chain charges, protein conformations, or the occupation of specific sites at specific domains or sites underlie the complex crosstalk. In summary, this review centers on elucidating the crosstalk between SUMOylation and other PTMs in breast cancer oncogenesis and progression and discuss the molecular mechanisms contributing to these interactions, offering insights into their potential applications in facilitating novel treatments for breast cancer.

Beyond the Usual Suspects: Examining the Role of Understudied Histone Variants in Breast Cancer

The incorporation of histone variants has structural ramifications on nucleosome dynamics and stability. Due to their unique sequences, histone variants can alter histone-histone or histone-DNA interactions, impacting the folding of DNA around the histone octamer and the overall higher-order structure of chromatin fibers. These structural modifications alter chromatin compaction and accessibility of DNA by transcription factors and other regulatory proteins to influence gene regulatory processes such as DNA damage and repair, as well as transcriptional activation or repression. Histone variants can also generate a unique interactome composed of histone chaperones and chromatin remodeling complexes. Any of these perturbations can contribute to cellular plasticity and the progression of human diseases. Here, we focus on a frequently overlooked group of histone variants lying within the four human histone gene clusters and their contribution to breast cancer.

Neoantigens and cancer-testis antigens as promising vaccine candidates for triple-negative breast cancer: Delivery strategies and clinical trials

Immunotherapy is gaining prominence as a promising strategy for treating triple-negative breast cancer (TNBC). Neoantigens (neoAgs) and cancer-testis antigens (CTAs) are tumor-specific targets originating from somatic mutations and epigenetic changes in cancer cells. These antigens hold great promise for personalized cancer vaccines, as supported by preclinical and early clinical evidence in TNBC. This review delves into the potential of neoAgs and CTAs as vaccine candidates, emphasizing diverse strategies and delivery approaches. It also highlights the current status of vaccination modalities undergoing clinical trials in TNBC therapy. A comprehensive understanding of neoAgs, CTAs, vaccination strategies, and innovative delivery methods is crucial for optimizing neoAg-based immunotherapies in clinical practice.

Epigenetic modulations in triple-negative breast cancer: Therapeutic implications for tumor microenvironment

Triple-negative breast cancer (TNBC) is an aggressive subtype lacking estrogen receptors, progesterone receptors and lacks HER2 overexpression. This absence of critical molecular targets poses significant challenges for conventional therapies. Immunotherapy, remarkably immune checkpoint blockade, offers promise for TNBC treatment, but its efficacy remains limited. Epigenetic dysregulation, including altered DNA methylation, histone modifications, and imbalances in regulators such as BET proteins, plays a crucial role in TNBC development and resistance to treatment. Hypermethylation of tumor suppressor gene promoters and the imbalance of histone methyltransferases such as EZH2 and histone deacetylases (HDACs) profoundly influence tumor cell proliferation, survival, and metastasis. In addition, epigenetic alterations critically shape the tumor microenvironment (TME), including immune cell composition, cytokine signaling, and immune checkpoint expression, ultimately contributing to immune evasion. Targeting these epigenetic mechanisms with specific inhibitors such as EZH2 and HDAC inhibitors in combination with immunotherapy represents a compelling strategy to remodel the TME, potentially overcoming immune evasion and enhancing therapeutic outcomes in TNBC. This review aims to comprehensively elucidate the current understanding of epigenetic modulation in TNBC, its influence on the TME, and the potential of combining epigenetic therapies with immunotherapy to overcome the challenges posed by this aggressive breast cancer subtype.

Overcoming doxorubicin resistance in triple-negative breast cancer using the class I-targeting HDAC inhibitor bocodepsin/OKI-179 to promote apoptosis

BACKGROUND

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with a poor prognosis. Doxorubicin is part of standard curative therapy for TNBC, but chemotherapy resistance remains an important clinical challenge. Bocodepsin (OKI-179) is a small molecule class I histone deacetylase (HDAC) inhibitor that promotes apoptosis in TNBC preclinical models. The purpose of this study was to investigate the combination of bocodepsin and doxorubicin in preclinical TNBC models and evaluate the impact on terminal cell fate, including apoptosis and senescence.

METHODS

TNBC cell lines were treated with doxorubicin and CellTiter-Glo was used to assess proliferation and determine doxorubicin sensitivity. Select cell lines were treated with OKI-005 (in vitro version of bocodepsin) and doxorubicin and assessed for proliferation, apoptosis as measured by Annexin V/PI, and cell cycle by flow cytometry. Immunoblotting was used to assess changes in mediators of apoptosis, cell cycle arrest, and senescence. Senescence was measured by the senescence-associated β-galactosidase assay. An MDA-MB-231 xenograft in vivo model was treated with bocodepsin, doxorubicin, or the combination and assessed for inhibition of tumor growth. shRNA knockdown of p53 was performed in the CAL-51 cell line and proliferation, apoptosis and senescence were assessed in response to combination treatment.

RESULTS

OKI-005 and doxorubicin resulted in synergistic antiproliferative activity in TNBC cells lines regardless of p53 mutation status. The combination led to increased apoptosis and decreased senescence. In vivo, the combination resulted in increased tumor growth inhibition compared to either single agent. shRNA knock-down of p53 led to increased doxorubicin-induced senescence that was decreased with the addition of OKI-005 in vitro.

CONCLUSION

The addition of bocodepsin to doxorubicin resulted in synergistic antiproliferative activity in vitro, improved tumor growth inhibition in vivo, and promotion of apoptosis which makes this a promising combination to overcome doxorubicin resistance in TNBC. Bocodepsin is currently in clinical development and has a favorable toxicity profile compared to other HDAC inhibitors supporting the feasibility of evaluating this combination in patients with TNBC.

A network-based drug prioritization and combination analysis for the MEK5/ERK5 pathway in breast cancer

BACKGROUND

Prioritizing candidate drugs based on genome-wide expression data is an emerging approach in systems pharmacology due to its holistic perspective for preclinical drug evaluation. In the current study, a network-based approach was proposed and applied to prioritize plant polyphenols and identify potential drug combinations in breast cancer. We focused on MEK5/ERK5 signalling pathway genes, a recently identified potential drug target in cancer with roles spanning major carcinogenesis processes.

RESULTS

By constructing and identifying perturbed protein-protein interaction networks for luminal A breast cancer, plant polyphenols and drugs from transcriptome data, we first demonstrated their systemic effects on the MEK5/ERK5 signalling pathway. Subsequently, we applied a pathway-specific network pharmacology pipeline to prioritize plant polyphenols and potential drug combinations for use in breast cancer. Our analysis prioritized genistein among plant polyphenols. Drug combination simulations predicted several FDA-approved drugs in breast cancer with well-established pharmacology as candidates for target network synergistic combination with genistein. This study also highlights the concept of target network enhancer drugs, with drugs previously not well characterised in breast cancer being prioritized for use in the MEK5/ERK5 pathway in breast cancer.

CONCLUSION

This study proposes a computational framework for drug prioritization and combination with the MEK5/ERK5 signaling pathway in breast cancer. The method is flexible and provides the scientific community with a robust method that can be applied to other complex diseases.

Advancements in dual-target inhibitors of PI3K for tumor therapy: Clinical progress, development strategies, prospects

Phosphoinositide 3-kinases (PI3Ks) modify lipids by the phosphorylation of inositol phospholipids at the 3'-OH position, thereby participating in signal transduction and exerting effects on various physiological processes such as cell growth, metabolism, and organism development. PI3K activation also drives cancer cell growth, survival, and metabolism, with genetic dysregulation of this pathway observed in diverse human cancers. Therefore, this target is considered a promising potential therapeutic target for various types of cancer. Currently, several selective PI3K inhibitors and one dual-target PI3K inhibitor have been approved and launched on the market. However, the majority of these inhibitors have faced revocation or voluntary withdrawal of indications due to concerns regarding their adverse effects. This article provides a comprehensive review of the structure and biological functions, and clinical status of PI3K inhibitors, with a specific emphasis on the development strategies and structure-activity relationships of dual-target PI3K inhibitors. The findings offer valuable insights and future directions for the development of highly promising dual-target drugs targeting PI3K.

Regulation of Hippo-YAP/CTGF signaling by combining an HDAC inhibitor and 5-fluorouracil in gastric cancer cells

Histone deacetylase (HDAC) inhibitors diminish carcinogenesis, metastasis, and cancer cell proliferation by inducing death in cancer cells. Tissue regeneration and organ development are highly dependent on the Hippo signaling pathway. Targeting the dysregulated hippo pathway is an excellent approach for cancer treatment. According to the results of this study, the combination of panobinostat, a histone deacetylase inhibitor, and 5-fluorouracil (5-FU), a chemotherapy drug, can act synergistically to induce apoptosis in gastric cancer cells. The combination of panobinostat and 5-FU was more effective in inhibiting cell viability than either treatment alone by elevating the protein levels of cleaved PARP and cleaved caspase-9. By specifically targeting E-cadherin, vimentin, and MMP-9, the combination of panobinostat and 5-FU significantly inhibited cell migration. Additionally, panobinostat significantly increased the anticancer effects of 5-FU by activating Hippo signaling (Mst 1 and 2, Sav1, and Mob1) and inhibiting the Akt signaling pathway. As a consequence, there was a decrease in the amount of Yap protein. The combination therapy of panobinostat with 5-FU dramatically slowed the spread of gastric cancer in a xenograft animal model by deactivating the Akt pathway and supporting the Hippo pathway. Since combination treatment exhibits much higher anti-tumor potential than 5-FU alone, panobinostat effectively potentiates the anti-tumor efficacy of 5-FU. As a result, it is believed that panobinostat and 5-FU combination therapy will be useful as supplemental chemotherapy in the future.

The HDAC inhibitor HFY-4A improves TUSC2 transcription to induce immunogenic cell death in breast cancer

We managed to explore the function of HFY-4A, a novel histone deacetylases (HDACs) inhibitor, on breast cancer as well as its potential mechanisms. MCF7 and T47D cells were treated with 0.8, 1.6 or 3.2 μM HFY-4A for 0-72 h, following of which CCK-8, colony formation, EdU staining, flow cytometry, Transwell, and wound healing assays were carried out. Western blot, immunohistochemistry, and ELISA were conducted for assaying the expression of immunogenic cell death (ICD)-related proteins. The interaction between HFY-4A, HDAC1, and tumor suppressor candidate 2 (TUSC2) was evaluated by chromatin immunoprecipitation assay. Further, the function of HFY-4A in breast cancer progression in vivo was evaluated using xenograft mouse models. HFY-4A inhibited the proliferation, migration, and invasion, and induced apoptosis of breast cancer cells in a dose-dependent manner. HFY-4A dose-dependently caused the ICD of breast cancer cells, as evidenced by the significant high levels of high-mobility group box 1 (HMGB1), calreticulin (CRT), heat shock protein 70 (HSP70), and HSP90. Interestingly, HFY-4A could facilitate TUSC2 transcription by promoting acetylation of histones on the TUSC2 promoter. The results of rescue assays revealed that HFY-4A repressed proliferation and mobility, but enhanced apoptosis and ICD through facilitating TUSC2 transcription in breast cancer. In breast cancer xenograft mouse models, HFY-4A was verified to inhibit tumor growth via upregulating TUSC2. HFY-4A could inhibit breast cancer cell proliferation and mobility, and enhanced apoptosis and ICD through facilitating TUSC2 transcription.

Tailoring Potential Natural Compounds for the Treatment of Luminal Breast Cancer

Breast cancer (BC) is the most diagnosed cancer worldwide, mainly affecting the epithelial cells from the mammary glands. When it expresses the estrogen receptor (ER), the tumor is called luminal BC, which is eligible for endocrine therapy with hormone signaling blockade. Hormone therapy is essential for the survival of patients, but therapeutic resistance has been shown to be worrying, significantly compromising the prognosis. In this context, the need to explore new compounds emerges, especially compounds of plant origin, since they are biologically active and particularly promising. Natural products are being continuously screened for treating cancer due to their chemical diversity, reduced toxicity, lower side effects, and low price. This review summarizes natural compounds for the treatment of luminal BC, emphasizing the activities of these compounds in ER-positive cells. Moreover, their potential as an alternative to endocrine resistance is explored, opening new opportunities for the design of optimized therapies.