Targeting nuclear hormone receptors for the prevention of breast cancer

Salicylaldehyde Benzoylhydrazones with Anticancer Activity and Selectivity: Design, Synthesis, and In Vitro Evaluation

Dimethoxy derivatives of salicylaldehyde benzoylhydrazone containing a methoxy group on both aromatic rings were designed and synthesized. The compounds were obtained in high yields, and their structures were confirmed by elemental analysis and various spectral techniques. In vitro evaluation of dimethoxy hydrazones demonstrated potent activity against the leukemic cell lines at low micro- and nanomolar concentrations. Remarkably, two dimethoxy analogs showed exceptional antileukemic selectivity, with no toxicity observed in normal human embryonic kidney HEK-293 cells. In silico modeling identified likely interactions with the target, human cAbl kinase, and suggested a possible mechanism for their antileukemic activity.

Acyl Urea Compounds Therapeutics and its Inhibition for Cancers in Women: A Review

Acyl urea compounds have garnered significant attention in cancer therapeutics, particularly for their potential effectiveness against cancers that predominantly affect women, such as breast and ovarian cancers. The paper presents a report on the investigation of acyl urea compounds that are reported to involve a multi-faceted approach, including synthetic chemistry, biological assays, and computational modeling. A wealth of information on acyl urea and its purported effects on cancer affecting women has been gathered from different sources and condensed to provide readers with a broad understanding of the role of acyl urea in combating cancer. Acylureas demonstrate promising results by selectively inhibiting key molecular targets associated with cancer progressions, such as EGFR, ALK, HER2, and the Wnt/β-catenin signaling pathway. Specifically, targeting acyl ureas impedes tumor proliferation and metastasis while minimizing harm to healthy tissues, offering a targeted therapeutic approach with reduced side effects compared to conventional chemotherapy. Continued research and clinical trials are imperative to optimize the efficacy and safety profiles of acylurea-based therapies and broaden their applicability across various cancer types. Acyl urea compounds represent a promising class of therapeutics for the treatment of cancers in women, particularly due to their ability to selectively inhibit key molecular targets involved in tumor growth and progression. The combination of synthetic optimization, biological evaluation, and computational modeling has facilitated the identification of several lead compounds with significant anticancer potential. This abstract explores the therapeutic mechanisms and targeted pathways of acyl ureas in combating these malignancies, which will be useful for future studies.

Leveraging nuclear receptor mediated transcriptional signaling for drug discovery: Historical insights and current advances

Nuclear receptors (NRs) are ligand-activated transcription factors that regulate gene expression in response to physiological signals, such as hormones and other chemical messengers. These receptors either activate or repress the transcription of target genes, which in turn promotes or suppresses physiological processes governing growth, differentiation, and homeostasis. NRs bind to specific DNA sequences and, in response to ligand binding, either promote or hinder the assembly of the transcriptional machinery, thereby influencing gene expression at the transcriptional level. These receptors are involved in a wide range of pathological conditions, including cancer, metabolic disorders, chronic inflammatory diseases, and immune system-related disorders. Modulation of NR function through targeted drugs has shown therapeutic benefits in treating such conditions. NR-targeted drugs, which either completely or selectively activate or block receptor function, represent a significant class of clinically valuable therapeutics. However, the pathways of NR-mediated gene expression and the resulting physiological effects are complex, involving crosstalk between various biomolecular components. As a result, NR-targeted drug discovery is challenging. With improved understanding of how NRs regulate physiological functions and deeper insights into their molecular structure, the process of NR-targeted drug discovery has evolved. While many traditional NR-targeting drugs are associated with side effects of varying severity, new drug candidates are being designed to minimize these adverse effects. Given that NR activity varies according to the tissue in which they are expressed and the specific isoform that is activated or repressed, achieving selectivity in targeting specific tissues and isoform classes may help reduce systemic side effects. In a recent breakthrough, the isoform-selective, hepato-targeted thyroid hormone-β agonist, Resmetirom (marketed as Rezdiffra), was approved for the treatment of non-alcoholic steatohepatitis. This chapter explores the structural and mechanistic principles guiding NR-targeted drug discovery and provides insights into recent developments in this field.

Differential role of glucocorticoid receptor based on its cell type specific expression on tumor cells and infiltrating lymphocytes

BACKGROUND

The glucocorticoid receptor (GR) is frequently expressed in breast cancer (BC), and its prognostic implications are contingent on estrogen receptor (ER) status. To address conflicting reports and explore therapeutic potential, a GR signature (GRsig) independent of ER status was developed. We also investigated cell type-specific GR protein expression in BC tumor epithelial cells and infiltrating lymphocytes.

METHODS

GRsig was derived from Dexamethasone treated cell lines through a bioinformatic pipeline. Immunohistochemistry assessed GR protein expression. Associations between GRsig and tumor phenotypes (proliferation, cytolytic activity (CYT), immune cell distribution, and epithelial-to-mesenchymal transition (EMT) were explored in public datasets. Single-cell RNA sequencing data evaluated context-dependent GR roles, and a cell type-specific prognostic role was assessed in an independent BC cohort.

RESULTS

High GRsig levels were associated with a favorable prognosis across BC subtypes. Tumor-specific high GRsig correlated with lower proliferation, increased CYT, and anti-tumorigenic immune cells. Single-cell data analysis revealed higher GRsig expression in immune cells, negatively correlating with EMT while a positive correlation was observed with EMT primarily in tumor and stromal cells. Univariate and multivariate analyses demonstrated the robust and independent predictive capability of GRsig for favorable prognosis. GR protein expression on immune cells in triple-negative tumors indicated a favorable prognosis.

CONCLUSION

This study underscores the cell type-specific role of GR, where its expression on tumor cells is associated with aggressive features like EMT, while in infiltrating lymphocytes, it predicts a better prognosis, particularly within TNBC tumors. The GRsig emerges as a promising independent prognostic indicator across diverse BC subtypes.

Retinoid X Receptor agonists as selective modulators of the immune system for the treatment of cancer

Upon heterodimerizing with other nuclear receptors, retinoid X receptors (RXR) act as ligand-dependent transcription factors, regulating transcription of critical signaling pathways that impact numerous hallmarks of cancer. By controlling both inflammation and immune responses, ligands that activate RXR can modulate the tumor microenvironment. Several small molecule agonists of these essential receptors have been synthesized. Historically, RXR agonists were tested for inhibition of growth in cancer cells, but more recent drug discovery programs screen new molecules for inhibition of inflammation or activation of immune cells. Bexarotene is the first successful example of an effective therapeutic that molecularly targets RXR; this drug was approved to treat cutaneous T cell lymphoma and is still used as a standard of care treatment for this disease. No additional RXR agonists have yet achieved FDA approval, but several promising novel compounds are being developed. In this review, we provide an overview of the multiple mechanisms by which RXR signaling regulates inflammation and tumor immunity. We also discuss the potential of RXR-dependent immune cell modulation for the treatment or prevention of cancer and concomitant challenges and opportunities.