Gefitinib-Tamoxifen Hybrid Ligands as Potent Agents against Triple-Negative Breast Cancer

Dysregulated Signaling Pathways in Canine Mammary Tumor and Human Triple Negative Breast Cancer: Advances and Potential Therapeutic Targets

In 2022, human breast cancer (HBC) and canine mammary tumors (CMTs) remained the most prevalent malignant tumors worldwide, with high recurrence and lethality rates, posing a significant threat to human and dog health. The development of breast cancer involves multiple signaling pathways, highlighting the need for effective inhibitory drugs that target key proteins in these pathways. This article reviews the dysregulation of the EGFR, PI3K/AKT/mTOR, Hippo, pyroptosis, and PD-1/PD-L1 signaling pathways in HBC and CMT, as well as the corresponding drugs used to inhibit tumor growth, with the aim of providing theoretical support for the development of more efficient drugs.

Cancer Cells Show Higher Sensitivity to Melatonin-Tamoxifen Drug Conjugates than to Combination of Melatonin and Tamoxifen

Drug conjugates of tamoxifen and melatonin linked through the amide side chain of melatonin (4a,4b) were reported as promising agents for future treatment of breast cancer, possibly reversing the adverse effects of tamoxifen. Here, we report the synthesis and pharmacological evaluation of a novel series of anticancer drug conjugates linking melatonin with tamoxifen through polymethylene spacers through the ether oxygen of melatonin (16a-c, 19a-c, 21) and compare them to the previously reported amide-linked analogues 4a and 4b. All hybrid ligands are antagonists of estrogen receptor alpha and agonists of the melatonin MT1 receptor with variable potencies. Several drug conjugates including the (CH2)4-linked analogues 4a and 16a and the (CH2)6-linked compound 16c showed higher potency to inhibit cell viability than the combination of melatonin and tamoxifen on at least one cancer cell line including MCF-7, MDA-MB-231, and HT-1080.

Design, synthesis and bioevaluation of dual EGFR-PI3Kα inhibitors for potential treatment of NSCLC

Aberrant activation or mutation of the EGFR-PI3K-Akt-mTOR signaling pathway has been implicated in a wide range of human cancers, especially non-small-cell lung cancer (NSCLC). Thus, dual inhibition of EGFR and PI3K has been investigated as a promising strategy to address acquired drug resistance resulting from the use of tyrosine kinase inhibitors. A series of dual EGFR/PI3Kα inhibitors was synthesized using pharmacophore hybridization of the third-generation EGFR inhibitor olmutinib and the PI3Kα selective inhibitor TAK-117. The optimal compound 30k showed potent kinase inhibitory activities with IC50 values of 3.6 and 30.0 nM against EGFRL858R/T790M and PI3Kα, respectively. Compound 30k exhibited a significant antiproliferative effect in NCI-H1975 cells with a higher selectivity profile than olmutinib. The potential antitumor mechanism, molecular binding modes, and in vitro metabolic stability of compound 30k were also clarified.

Receptor tyrosine kinases in breast cancer treatment: unraveling the potential

Breast cancer is a multifactorial disease driven by acquired genetic and epigenetic changes that lead to aberrant regulation of cellular signaling pathways. Receptor tyrosine kinases (RTKs), a class of critical receptors, are involved in the initiation and progression of breast cancer. RTKs are cell surface receptors with unique structures and biological characteristics, which respond to environmental signals by initiating signaling cascades such as the mitogen-activated protein kinase (MAPK) pathway, Janus kinase (JAK)/signal transducer, activator of transcription (STAT) pathway, and phosphoinositide 3-kinase (PI3K)/AKT pathway. The critical role of RTKs makes them suitable targets for breast cancer treatment. Targeted therapies against RTKs have been developed in recent years, evaluated in clinical trials, and approved for several cancer types, including breast cancer. However, breast cancer displays molecular heterogeneity and exhibits different therapeutic responses to various drug types, leading to limited effectiveness of targeted therapy against RTKs. In this review, we summarize the structural and functional characteristics of selected RTKs and discuss the mechanisms and current status of drug therapy involving different protein tyrosine kinases in breast cancer progression.

Design, synthesis, and biological studies of nitric oxide-donating piperlongumine derivatives triggered by lysyl oxidase as anti-triple negative breast cancer agents

Nitric oxide (NO) is an important gas messenger molecule with a wide range of biological functions. High concentration of NO exerts promising antitumor effects and is regarded as one of the hot spots in cancer research, that have limitations in their direct application due to its gaseous state, short half-life (seconds) and high reactivity. Lysyl oxidase (LOX) is a copper-dependent amine oxidase that is responsible for the covalent bonding between collagen and elastin and promotes tumor cell invasion and metastasis. The overexpression of LOX in triple-negative breast cancer (TNBC) makes it an attractive target for TNBC therapy. Herein, novel NO donor prodrug molecules were designed and synthesized based on the naturally derived piperlongumine (PL) skeleton, which can be selectively activated by LOX to release high concentrations of NO and PL derivatives, both of them play a synergistic role in TNBC therapy. Among them, the compound TM-1 selectively released NO in highly invasive TNBC cells (MDA-MB-231), and TM-1 was also confirmed as a potential TNBC cell line inhibitor with an inhibitory concentration of 2.274 μM. Molecular docking results showed that TM-1 had a strong and selective binding affinity with LOX protein.

Exploring Raloxifene-Based Metallodrugs: A Versatile Vector Combined with Platinum(II), Palladium(II) and Nickel(II) Dichlorides and Carborates against Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) poses challenges in therapy due to the absence of target expression such as estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). Frequently, the treatment of TNBC involves the combination of several therapeutics. However, an enhanced therapeutic effect can be also achieved within a single molecule. The efficacy of raloxifene can be improved by designing a raloxifene-based hybrid drug bearing a 2,2'-bipyridine moiety (2). Integration of platinum(II), palladium(II), and nickel(II) complexes into this structure dramatically changed the cytotoxicity. The platinum(II) dichloride complex 3 did not demonstrate any activity, while palladium(II) and nickel(II) dichloride complexes 4 and 5 exhibited various cytotoxic behavior towards different types of hormone-receptor positive (HR+) cancer and TNBC cell lines. The replacement of the two chlorido ligands in 3-5 with a dicarbollide (carborate) ion [C2B9H11]2- resulted in reduced activity of compounds 6, 7, and 8. However, the palladacarborane complex 7 demonstrated higher selectivity towards TNBC. Furthermore, the mechanism of action was shifted from cytotoxic to explicitly cytostatic with detectable proliferation arrest and accelerated aging, characterized by senescence-associated phenotype of TNBC cells. This study provides valuable insights into the development of hybrid therapeutics against TNBC.

Potential of covalently linked tamoxifen hybrids for cancer treatment: recent update

Cancer is a complex disease and the second leading cause of death globally, and breast cancer is still a leading cause of cancer death in women. Tamoxifen is the most commonly used drug for breast cancer (ER-positive) treatment and chemoprevention, saving the lives of millions of patients every year. In addition, the tamoxifen template has been explored extensively for the development of selective estrogen receptor modulators (SERMs) applicable in breast cancer, osteoporosis, and postmenopausal symptom treatment. Numerous anticancer drugs, including tamoxifen, are in use, but the complexity and heterogeneous nature of cancer complicate the effect of conventional targeted drugs, leading to adverse reactions and resistance. One of the significant approaches to overcome these shortcomings is drug hybrids, generated by covalently linking two or more active pharmacophores. These drug hybrids are remarkably effective in acting on multiple drug targets with higher selectivity and specificity. In recent years, several tamoxifen hybrids have been discovered as potential candidates for cancer treatment. The review highlights the recent progress in developing anticancer hybrids, including organometallic, fluorescent, photocaged, and novel ligand-based tamoxifen hybrids. It also demonstrates the significance of merging various pharmacophores with tamoxifen to produce more potent, precise, and effective anticancer agents. The study offers valuable knowledge to researchers working on cancer research with the hope of enhancing drug potency and reducing drug toxicity to improve cancer patients' lives.

Unraveling breast cancer prognosis: a novel model based on coagulation-related genes

Objective

Breast cancer is highly heterogeneous, presenting challenges in prognostic assessment. Developing a universally applicable prognostic model could simplify clinical decision-making. This study aims to develop and validate a novel breast cancer prognosis model using coagulation-related genes with broad clinical applicability.

Methods

A total of 203 genes related to coagulation were obtained from the KEGG database, and the mRNA data of 1,099 tumor tissue samples and 572 samples of normal tissue were retrieved from the TCGA-BRCA cohort and GTEx databases. The R package "limma" was utilized to detect variations in gene expression related to coagulation between the malignancies and normal tissue. A model was constructed in the TCGA cohort through a multivariable Cox regression analysis, followed by validation using the GSE42568 dataset as the testing set. Constructing a nomogram incorporating clinical factors to enhance the predictive capacity of the model. Utilizing the ESTIMATE algorithm to investigate the immune infiltration levels in groups with deferent risk. Performing drug sensitivity analysis using the "oncoPredict" package.

Results

A risk model consisting of six coagulation-associated genes (SERPINA1, SERPINF2, C1S, CFB, RASGRP1, and TLN2) was created and successfully tested for validation. Identified were 6 genes that serve as protective factors in the model's development. Kaplan-Meier curves revealed a worse prognosis in the high-risk group compared to the low-risk group. The ROC analysis showed that the model accurately forecasted the overall survival (OS) of breast cancer patients at 1, 3, and 5 years. Nomogram accompanied by calibration curves can also provide better guidance for clinical decision-making. The low-risk group is more likely to respond well to immunotherapy, whereas the high-risk group may show improved responses to Gemcitabine treatment. Furthermore, individuals in distinct risk categories displayed different responses to various medications within the identical therapeutic category.

Conclusion

We established a breast cancer prognostic model incorporating six coagulation-associated genes and explored its clinical utility. This model offers valuable insights for clinical decision-making and drug selection in breast cancer patients, contributing to personalized and precise treatment advancements.

Dual-target inhibitors based on ERα: Novel therapeutic approaches for endocrine resistant breast cancer

Estrogen receptor alpha (ERα), a nuclear transcription factor, is a well-validated therapeutic target for more than 70% of all breast cancers (BCs). Antagonizing ERα either by selective estrogen receptor modulators (SERMs) or selective estrogen receptor degraders (SERDs) forms the foundation of endocrine therapy and has achieved great success in the treatment of ERα positive (ERα+) BCs. Unfortunately, despite initial effectiveness, endocrine resistance eventually emerges in up to 30% of ERα+ BC patients and remains a significant medical challenge. Several mechanisms implicated in endocrine resistance have been extensively studied, including aberrantly activated growth factor receptors and downstream signaling pathways. Hence, the crosstalk between ERα and another oncogenic signaling has led to surge of interest to develop combination therapies and dual-target single agents. This review briefly introduces the synergisms between ERα and another anticancer target and summarizes the recent advances of ERα-based dual-targeting inhibitors from a medicinal chemistry perspective. Accordingly, their rational design strategies, structure-activity relationships (SARs) and biological activities are also dissected to provide some perspectives on future directions for ERα-based dual target drug discovery in BC therapy.

Design and synthesis of dual BRD4/Src inhibitors for treatment of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an extremely aggressive tumor with limited treatment options and effectiveness. Dual-target inhibitors capable of simultaneously suppressing invasion may represent a promising therapeutic approach for TNBC. In this work, we developed a series of dual BRD4/Src inhibitors by connecting JQ1 and dasatinib using various linkers and evaluated their efficacy against TNBC both in vitro and in vivo. Among these compounds, HL403 demonstrated IC50 values of 133 nM for BRD4 inhibition and 4.5 nM for Src inhibition. Most importantly, HL403 not only exhibited potent anti-proliferative capabilities, but also effectively suppressed the invasion of MDA-MB-231 cells in vitro. Finally, the anti-tumor efficacy of HL403 was validated in a mouse MDA-MB-231 xenograft tumor model, achieving a tumor growth inhibition rate (TGI) of 70.7 %, which was superior to the combination of JQ1 and dasatinib (TGI = 54.0 %). Our research provides a promising and feasible new strategy for improving the treatment of TNBC.

RelB-activated GPX4 inhibits ferroptosis and confers tamoxifen resistance in breast cancer

Tamoxifen (TAM) resistance remains a major obstacle in the treatment of advanced breast cancer (BCa). In addition to the competitive inhibition of the estrogen receptor (ER) signaling pathway, damping of mitochondrial function by increasing reactive oxygen species (ROS) is critical for enhancing TAM pharmacodynamics. Here, we showed that RelB contributes to TAM resistance by inhibiting TAM-provoked ferroptosis. TAM-induced ROS level promoted ferroptosis in TAM-sensitive cells, but the effect was alleviated in TAM-resistant cells with high constitutive levels of RelB. Mechanistically, RelB inhibited ferroptosis by transcriptional upregulating glutathione peroxidase 4 (GPX4). Consequently, elevating RelB and GPX4 in sensitive cells increased TAM resistance, and conversely, depriving RelB and GPX4 in resistant cells decreased TAM resistance. Furthermore, suppression of RelB transcriptional activation resensitized TAM-resistant cells by enhancing ferroptosis in vitro and in vivo. The inactivation of GPX4 in TAM-resistant cells consistently resensitized TAM by increasing ferroptosis-mediated cell death. Together, this study uncovered that inhibition of ferroptosis contributes to TAM resistance of BCa via RelB-upregulated GPX4.

Recent Advances in Drug Discovery for Triple-Negative Breast Cancer Treatment

Triple-negative breast cancer (TNBC) is one of the most heterogeneous and aggressive breast cancer subtypes with a high risk of death on recurrence. To date, TNBC is very difficult to treat due to the lack of an effective targeted therapy. However, recent advances in the molecular characterization of TNBC are encouraging the development of novel drugs and therapeutic combinations for its therapeutic management. In the present review, we will provide an overview of the currently available standard therapies and new emerging therapeutic strategies against TNBC, highlighting the promises that newly developed small molecules, repositioned drugs, and combination therapies have of improving treatment efficacy against these tumors.

Development of First-in-Class Dual Sirt2/HDAC6 Inhibitors as Molecular Tools for Dual Inhibition of Tubulin Deacetylation

Dysregulation of both tubulin deacetylases sirtuin 2 (Sirt2) and the histone deacetylase 6 (HDAC6) has been associated with the pathogenesis of cancer and neurodegeneration, thus making these two enzymes promising targets for pharmaceutical intervention. Herein, we report the design, synthesis, and biological characterization of the first-in-class dual Sirt2/HDAC6 inhibitors as molecular tools for dual inhibition of tubulin deacetylation. Using biochemical in vitro assays and cell-based methods for target engagement, we identified Mz325 (33) as a potent and selective inhibitor of both target enzymes. Inhibition of both targets was further confirmed by X-ray crystal structures of Sirt2 and HDAC6 in complex with building blocks of 33. In ovarian cancer cells, 33 evoked enhanced effects on cell viability compared to single or combination treatment with the unconjugated Sirt2 and HDAC6 inhibitors. Thus, our dual Sirt2/HDAC6 inhibitors are important new tools to study the consequences and the therapeutic potential of dual inhibition of tubulin deacetylation.

LIMS-Kinase provides sensitive and generalizable label-free in vitro measurement of kinase activity using mass spectrometry

Measurements of kinase activity are important for kinase-directed drug development, analysis of inhibitor structure and function, and understanding mechanisms of drug resistance. Sensitive, accurate, and miniaturized assay methods are crucial for these investigations. Here, we describe a label-free, high-throughput mass spectrometry-based assay for studying individual kinase enzymology and drug discovery in a purified system, with a focus on validated drug targets as benchmarks. We demonstrate that this approach can be adapted to many known kinase substrates and highlight the benefits of using mass spectrometry to measure kinase activity in vitro, including increased sensitivity. We speculate that this approach to measuring kinase activity will be generally applicable across most of the kinome, enabling research on understudied kinases and kinase drug discovery.

Coordination-Driven Salamo-Salen-Salamo-Type Multinuclear Transition Metal(II) Complexes: Synthesis, Structure, Luminescence, Transformation of Configuration, and Nuclearity Induced by the Acetylacetone Anion

A flexible polydentate Salamo-Salen-Salamo hybrid ligand H₄L was designed and synthesized, which has rich pockets (salamo and salen pockets) so that it may have fascinating coordination patterns with transition metal(II) ions. Four multinuclear transition metal(II) complexes, novel butterfly-shaped homotetranuclear [Ni₄(L)(μ₁-OAc)₂(μ_1,3-OAc)₂(H₂O)_0.5(CH₃CH₂OH)_3.5]·4CH₃CH₂OH (1), helical homotrinuclear [Zn₃(L)(μ₁-OAc)₂]·2CH₃CH₂OH (2), double-helical homotrinuclear [Cu₂(H₂L)₂]·2CH₃CN (3), and mononuclear [Ni(H₂L)]·1.5CH₃COCH₃ (4), have been synthesized and characterized by single-crystal X-ray diffraction. The effects of different anions [OAc^- and (O₂C₅H₇)^2-] on the complexation behavior of H₄L with transition metal(II) ions were studied by UV-vis spectrophotometry. The fluorescent properties of the four complexes were studied with zebrafish, which are expected to be a potential light-emitting material. Ultimately, interaction region indicator (IRI) valuations, Hirshfeld surface analyses, density functional theory (DFT & TD-DFT), electrostatic potential analyses (ESP), and simulations were carried out to further demonstrate the weak interactions and electronic properties of the free ligand and its four complexes.

Therapeutic significance of molecular hybrids for breast cancer research and treatment

Worldwide, breast cancer is still a leading cause of cancer death in women. Indeed, over the years, several anti-breast cancer drugs have been developed; however, the complex heterogeneous nature of breast cancer disease reduces the applicability of conventional targeted therapies with the upsurge in side effects and multi-drug resistance. Molecular hybrids generated by a combination of two or more active pharmacophores emerged as a promising approach in recent years for the design and synthesis of anti-breast cancer drugs. The hybrid anti-breast cancer molecules are well known for their several advantages compared to the parent moiety. These hybrid forms of anti-breast cancer molecules demonstrated remarkable effects in blocking different pathways contributing to the pathogenies of breast cancer and improved specificity. In addition, these hybrids are patient compliant with reduced side effects and multi-drug resistance. The literature revealed that molecular hybrids are applied to discover and develop novel hybrids for various complex diseases. This review article highlights the recent progress (∼2018-2022) in developing molecular hybrids, including linked, merged, and fused hybrids, as promising anti-breast cancer agents. Furthermore, their design principles, biological potential, and future perspective are discussed. The provided information will lead to the development of novel anti-breast cancer hybrids with excellent pharmacological profiles in the future.

Anticancer Drug Conjugates Incorporating Estrogen Receptor Ligands

Hormone-dependent cancers, such as certain types of breast cancer are characterized by over-expression of estrogen receptors (ERs). Anticancer drug conjugates combining ER ligands with other classes of anticancer agents may not only benefit from dual action at both anti-cancer targets but also from selective delivery of cytotoxic agents to ER-positive tumor cells resulting in less toxicity and adverse effects. Moreover, they could also take advantage of overcoming resistance typical for anti-hormonal monotherapy such as tamoxifen. In this review, we discuss the design, structures and pharmacological effects of numerous series of drug conjugates containing ER ligands such as selective ER modulators (tamoxifen, 4-hydroxytamoxifen, endoxifen), selective ER degraders (ICI-164384) and ER agonists (estradiol) linked to diverse anti-cancer agents including histone-deacetylase inhibitors, DNA-alkylating agents, antimitotic agents and epidermal growth factor receptor inhibitors.

Oncogenic roles of LINC01234 in various forms of human cancer

Abnormal expression of long non-coding RNAs (lncRNAs) plays an essential role in various malignant neoplasia. As a newly identified lncRNA, LINC01234 is abnormally expressed in several types of cancers and promotes the development of cancers. Accumulating evidence indicates that overexpression of LINC01234 is associated with poor clinical outcomes. Moreover, LINC01234 modulates many cellular events as a putative proto-oncogene, including proliferation, migration, invasion, apoptosis, cell cycle progression, and EMT. In terms of molecular mechanism, LINC01234 regulates gene expression by acting as ceRNA, participating in signaling pathways, interacting with proteins and other molecules, and encoding polypeptide. It reveals that LINC01234 may serve as a potential biomarker for cancer diagnosis, treatment, and prognosis. This review summarizes the expression pattern, biological function, and molecular mechanism of LINC01234 in human cancer and discusses its potential clinical utility.

Comparative analysis of transient receptor potential channel 5 opposite strand-induced gene expression patterns and protein-protein interactions in triple-negative breast cancer

In patients with triple-negative breast cancer (TNBC), high tumour mutation burden and aberrant oncogene expression profiles are some of the causes of poor prognosis. Therefore, it is necessary to identify aberrantly expressed oncogenes, since they have the potential to serve as therapeutic targets. Transient receptor potential channel 5 opposite strand (TRPC5OS) has been previously shown to function as a novel tumour inducer. However, the underlying mechanism of TRPC5OS function in TNBC remain to be elucidated. Therefore, in the present study TRPC5OS expression was first measured in tissue samples of patients with TNBC and a panel of breast cancer cell lines (ZR-75-1, MDA-MB-453, SK-BR-3, JIMT-1, BT474 and HCC1937) by using qRT-PCR and Western blotting. Subsequently, the possible effects of TRPC5OS on MDA-MB-231 cells proliferation were determined using Cell Counting Kit-8 and 5-Ethynyl-2′-deoxyuridine assays after Lentiviral transfection of MDA-MB-231. In addition, potential interaction partners of TRPC5OS were explored using liquid chromatography-mass spectrometry (LC-MS)/MS. Gene expression patterns following TRPC5OS overexpression were also detected in MDA-MB-231 cells by using High-throughput sequencing. Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) analysis were then used to systematically verify the potential interactions among the TRPC5OS-regulated genes. The potential relationship between TRPC5OS-interacting proteins and gene expression patterns were studied using Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) analysis. TRPC5OS expression was found to be significantly higher in TNBC tumour tissues and breast cancer cell lines compared with luminal tumour tissues and ZR-75-1. In addition, the overexpression of TRPC5OS significantly increased cell proliferation. High-throughput sequencing results revealed that 5,256 genes exhibited differential expression following TRPC5OS overexpression, including 3,269 upregulated genes and 1,987 downregulated genes. GO analysis results indicated that the functions of these differentially expressed genes were enriched in the categories of ‘cell division’ and ‘cell proliferation’ regulation. KEGG analysis showed that the TRPC5OS-regulated genes were associated with processes of ‘homologous recombination’ and ‘TNF signalling pathways’. Subsequently, 17 TRPC5OS-interacting proteins were found using LC-MS/MS and STRING analysis. The most important protein among interacting proteins was ENO1 which was associated with glycolysis and regulated proliferation of cancer. In summary, data from the present study suggest that TRPC5OS overexpression can increase TNBC cell proliferation and ENO1 may be a potential target protein mediated by TRPC5OS. Therefore, TRPC5OS may serve as a novel therapeutic target for TNBC.