Natural products as promising modulators of breast cancer immunotherapy

Antitumor and immunomodulatory activities of diphyllin and its derivatives

Immune surveillance plays a key role in controlling tumor formation and development, and immune cell-based therapies, such as chimeric antigen receptor (CAR)-T cells and CAR-natural killer (NK) cells, have become important for the treatment of cancer. The proton pump (PP), vacuolar H+-ATPase (V-ATPase), acidifies intracellular organelles, pumps protons across the cell plasma membranes, and regulates the activity of various signaling pathways, and thus has been regarded as a potential target for cancer treatment. In addition, V-ATPase plays an important role in cytotoxic T lymphocytes, extracellular vesicle (EV) endocytosis, innate immune responses (IIR), and phagocytosis and hence has the potential to function as a target for the enhancement of immunotherapy. As potent V-ATPase inhibitors, the arylnaphthalene lignans, diphyllin and its derivatives, have exhibited potent antitumor and immunomodulatory activities. The structurally related aryltetralin lignan, podophyllotoxin, has served as a lead compound for both etoposide and teniposide, which have been developed as effective anticancer agents. In the present review, the role of V-ATPase in cancer immunotherapy and the structure-activity relationships (SARs) of diphyllin and its cytotoxic and V-ATPase inhibitory activities and the mechanisms of action are discussed. Also, the promise of diphyllin and its derivatives in the development of new adjuvants for cancer immunotherapies has been proposed.

Nuclear receptors in cancer: Unveiling theranostic potentials and innovative therapeutic strategies

Nuclear receptors (NRs) include a family of 48 transcription factors (TFs) that regulate gene expression implicated in biological processes such as cell proliferation, differentiation, metabolism, and immune response. Cancer development has been widely linked to the dysregulation of NRs and their signaling pathways, providing promising targets for therapeutic applications. Recent progress in OMIC approaches and high-throughput drug screening has facilitated the emergence of biomolecules, especially phytochemicals, as potential substitutes for synthetic anti-cancer drugs. This review aims to highlight the anticancer potency of diverse classes of biocompounds that target NRs, including phytocompounds, dietary components, venom constituents, microbial metabolites, as well as many small molecules generated from computer-aided drug design (CADD) approaches in the design of innovative and safe treatments. We examine critically the preclinical and clinical trials investigating these candidates for preventing and treating cancer, focusing on their modes of action, their proven efficacy, and their limitations. In addition, we underline significant molecular processes modulated by these natural compounds, highlighting their ability to surmount drug resistance and minimize the toxic effects of standard treatments. Overall, we believe this work has the potential to pave the way for new paradigms in identifying innovative therapeutic options for NR-mediated management of specific types of cancer.