Antimyeloma Potential of Caffeic Acid Phenethyl Ester and Its Analogues through Sp1 Mediated Downregulation of IKZF1-IRF4-MYC Axis

Anticancer potential of hydroxycinnamic acids: mechanisms, bioavailability, and therapeutic applications

Hydroxycinnamic acids (HCAs) are plant compounds with anticancer potential due to their antioxidant, anti-inflammatory, apoptosis-inducing, and proliferation-inhibiting effects. This review aims to consolidate and analyze current knowledge on the anticancer effects of HCAs, exploring their mechanisms of action, bioavailability challenges, and potential therapeutic applications. A comprehensive literature search on PubMed/MedLine, Scopus, Web of Science, and Google Scholar focused on the anticancer properties, mechanisms, bioavailability, and safety profiles of HCAs. Studies have shown that HCAs, such as caffeic acid, ferulic acid, and sinapic acid, inhibit the growth of cancer cells in vitro and in vivo and sensitize cancer cells to chemotherapy and radiation therapy. These effects are mediated by mechanisms including the inhibition of cell survival pathways, modulation of gene expression, and induction of oxidative stress and DNA damage. Additionally, several studies have demonstrated that HCAs exhibit selective toxicity, with a higher propensity to induce cell death in cancerous cells compared to normal cells. However, the toxicity profile of HCAs can vary depending on the specific compound, dosage, and experimental conditions. The anticancer properties of HCAs suggest potential applications in cancer prevention and treatment. However, it is essential to distinguish between their use as dietary supplements and therapeutic agents, as the dosage and formulation suitable for dietary supplements may be insufficient for therapeutic purposes. The regulatory and practical implications of using HCAs in these different contexts require careful consideration. Further research is needed to determine appropriate dosages, formulations, long-term effects, and regulatory frameworks for HCAs as both dietary supplements and therapeutic agents.

Flow and On-Water Synthesis and Cancer Cell Cytotoxicity of Caffeic Acid Phenethyl Amide (CAPA) Derivatives

Caffeic acid phenethyl ester (CAPE) is a phenolic natural product with a wide range of biological activities, including anticancer activity; however, the ester group of CAPE is metabolically labile. The corresponding amide, CAPA, has improved metabolic stability but limited anticancer activity relative to CAPE. We report the synthesis using flow and on-water Wittig reaction approaches of five previously reported and five novel CAPA analogues. All of these analogues lack the reactive catechol functionality of CAPA and CAPE. Cytotoxicity studies of CAPE, CAPA, and these CAPA analogues in HeLa and BE(2)-C cells were carried out. Surprisingly, we found that CAPA is cytotoxic against the neuroblastoma BE(2)-C cell line (IC50 = 12 µM), in contrast to the weak activity of CAPA against HeLa cells (IC50 = 112 µM), and the literature reports of the absence of activity for CAPA against a variety of other cancer cell lines. One novel CAPA analogue, 3f, was identified as having cytotoxic activity similar to CAPE in HeLa cells (IC50 = 63 µM for 3f vs. 32 µM for CAPE), albeit with lower activity against BE(2)-C cells (IC50 = 91 µM) than CAPA. A different CAPA analogue, 3g, was found to have similar effects against BE(2)-C cells (IC50 = 92 µM). These results show that CAPA is uniquely active against neuroblastoma cells and that specific CAPA analogues that are predicted to be more metabolically stable than CAPE can reproduce CAPA's activity against neuroblastoma cells and CAPE's activity against HeLa cells.

Tumor integrin targeted theranostic iron oxide nanoparticles for delivery of caffeic acid phenethyl ester: preparation, characterization, and anti-myeloma activities

Multiple myeloma (MM) is characterized by the accumulation of malignant plasma cells preferentially in the bone marrow. Currently, emerging chemotherapy drugs with improved biosafety profiles, such as immunomodulatory agents and protease inhibitors, have been used in clinics to treat MM in both initial therapy or maintenance therapy post autologous hematopoietic stem cell transplantation (ASCT). We previously discovered that caffeic acid phenethyl ester (CAPE), a water-insoluble natural compound, inhibited the growth of MM cells by inducing oxidative stress. As part of our continuous effort to pursue a less toxic yet more effective therapeutic approach for MM, the objective of this study is to investigate the potential of CAPE for in vivo applications by using magnetic resonance imaging (MRI)-capable superparamagnetic iron oxide nanoparticles (IONP) as carriers. Cyclo (Arg-Gly-Asp-D-Phe-Cys) (RGD) is conjugated to IONP (RGD-IONP/CAPE) to target the overexpressed αvβ3 integrin on MM cells for receptor-mediated internalization and intracellular delivery of CAPE. A stable loading of CAPE on IONP can be achieved with a loading efficiency of 48.7% ± 3.3% (wt%). The drug-release studies indicate RGD-IONP/CAPE is stable at physiological (pH 7.4) and basic pH (pH 9.5) and subject to release of CAPE at acidic pH (pH 5.5) mimicking the tumor and lysosomal condition. RGD-IONP/CAPE causes cytotoxicity specific to human MM RPMI8226, U266, and NCI-H929 cells, but not to normal peripheral blood mononuclear cells (PBMCs), with IC50s of 7.97 ± 1.39, 16.75 ± 1.62, and 24.38 ± 1.71 μM after 72-h treatment, respectively. Apoptosis assays indicate RGD-IONP/CAPE induces apoptosis of RPMI8226 cells through a caspase-9 mediated intrinsic pathway, the same as applying CAPE alone. The apoptogenic effect of RGD-IONP/CAPE was also confirmed on the RPMI8226 cells co-cultured with human bone marrow stromal cells HS-5 in a Transwell model to mimic the MM microenvironment in the bone marrow. In conclusion, we demonstrate that water-insoluble CAPE can be loaded to RGD-IONP to greatly improve the biocompatibility and significantly inhibit the growth of MM cells in vitro through the induction of apoptosis. This study paves the way for investigating the MRI-trackable delivery of CAPE for MM treatment in animal models in the future.

Therapeutic efficacy of caffeic acid phenethyl ester in cancer therapy: An updated review

Nowadays, there is a lot of public and scientific interest in using phytochemicals to treat human ailments. Existing cancer medicines still run across obstacles, despite significant advancements in the field. For instance, chemotherapy may result in severe adverse effects, increased drug resistance, and treatment failure. Natural substances that are phytochemically derived provide innovative approaches as potent therapeutic molecules for the treatment of cancer. Bioactive natural compounds may enhance chemotherapy for cancer by increasing the sensitivity of cancer cells to medicines. Propolis has been found to interfere with the viability of cancer cells, among other phytochemicals. Of all the components that make up propolis, caffeic acid phenethyl ester (CAPE) (a flavonoid) has been the subject of the most research. It demonstrates a broad spectrum of therapeutic uses, including antitumor, antimicrobial, antiviral, anti-inflammatory, immunomodulatory, hepatoprotective, neuroprotective, and cardioprotective effects. Studies conducted in vitro and in vivo have demonstrated that CAPE specifically targets genes involved in cell death, cell cycle regulation, angiogenesis, and metastasis. By altering specific signaling cascades, such as the NF-κB signaling pathway, CAPE can limit the proliferation of human cancer cells. This review highlights the research findings demonstrating the anticancer potential of CAPE with a focus on multitargeted molecular and biological implications in various cancer models.

Polyphenols: Chemoprevention and therapeutic potentials in hematological malignancies

Polyphenols are one of the largest plant-derived natural product and they play an important role in plants' defense as well as in human health and disease. A number of them are pleiotropic molecules and have been shown to regulate signaling pathways, immune response and cell growth and proliferation which all play a role in cancer development. Hematological malignancies on the other hand, are cancers of the blood. While current therapies are efficacious, they are usually expensive and with unwanted side effects. Thus, the search for newer less toxic agents. Polyphenols have been reported to possess antineoplastic properties which include cell cycle arrest, and apoptosis via multiple mechanisms. They also have immunomodulatory activities where they enhance T cell activation and suppress regulatory T cells. They carry out these actions through such pathways as PI3K/Akt/mTOR and the kynurenine. They can also reverse cancer resistance to chemotherapy agents. In this review, i look at some of the molecular mechanism of action of polyphenols and their potential roles as therapeutic agents in hematological malignancies. Here i discuss their anti-proliferative and anti-neoplastic activities especially their abilities modulate signaling pathways as well as immune response in hematological malignancies. I also looked at clinical studies done mainly in the last 10-15 years on various polyphenol combination and how they enhance synergism. I recommend that further preclinical and clinical studies be carried out to ensure safety and efficacy before polyphenol therapies be officially moved to the clinics.

Ketone Analog of Caffeic Acid Phenethyl Ester Exhibits Antioxidant Activity via Activation of ERK-Dependent Nrf2 Pathway

Due to their robust antioxidant properties, phenolic acids and their analogs are extensively studied for their ability to activate cellular antioxidant pathways, including nuclear factor (erythroid-derived-2)-like 2 (Nrf2)-antioxidant response element (ARE) pathway. Caffeic, ferulic, and gallic acid are well-studied members of phenolic acids. Constant efforts are made to improve the pharmacological effects and bioavailability of phenolic acids by synthesizing their chemical derivatives. This study determines how modifications of the chemical structure of these phenolic acids affect their antioxidant and cytoprotective activities. We have selected six superior antioxidant compounds (12, 16, 26, 35, 42, and 44) of the 48 caffeic acid phenethyl ester (CAPE) analogs based on their ability to scavenge free radicals in vitro using standard antioxidant assays. These compounds exhibited minimal toxicity as indicated by cell cycle and cytochrome C release assays. Among these compounds, 44, the ketone analog of CAPE, exhibited the ability to increase p-Nrf2 (Ser40) levels in 293T cells (p < 0.05). Further, 44, exhibited its antioxidant effect in Drosophila Melanogaster as indicated by an increase in mRNA levels of Nrf2 and GPx (p < 0.05). Finally, the ability of 44 to activate the antioxidant pathway was abolished in the presence of extracellular signal-regulated kinase (ERK) inhibitor in 293T cells. Thus, we identify 44, the ketone analog of CAPE, as a unique antioxidant molecule with the function of ERK-mediated Nrf2 activation.

Cardiac Expression of Esophageal Cancer-Related Gene-4 is Regulated by Sp1 and is a Potential Early Target of Doxorubicin-Induced Cardiotoxicity

Esophageal Cancer-Related Gene 4 (Ecrg4) expressed in cardiomyocytes and the cardiac conduction system is downregulated during cardiac ischemia and atrial fibrillation. To explore whether Ecrg4 plays any role in doxorubicin (DOX)-induced cardiotoxicity. Rats and neonatal rat cardiomyocytes (NRCMs) were employed to study the effect of DOX on Ecrg4 transcription. Bioinformatics combined with promoter analysis were used to map the rat Ecrg4 promoter. ChIP assay was used to evaluate the binding of Sp1 to the Ecrg4 promoter. Transient transfection was used to study the effect of Sp1 on the expression of endogenous Ecrg4. DOX decreased endogenous Ecrg4 gene expression in the heart and cultured NRCMs. In silico analysis showed that the 5'UTR immediately upstream of the start codon ATG, harbors a putative promoter that is GC-rich, and contains CpG islands, multiple overlapping Sp1sites. Transcription is initiated mainly on the 'C' at - 15. Serial 5'-deletion combined with dual-luciferase assays showed that the rat Ecrg4 core promoter resides at - 1/- 800. Sp1 transactivated Ecrg4 gene, which was almost abolished by DOX. Furthermore, ChIP assay showed that Sp1 specifically bound to the Ecrg4 promoter was interrupted by DOX. Finally, DOX suppressed Sp1 protein expression, and restoration of Sp1 increased Ecrg4 expression that was resistant to DOX-induced Ecrg4 downregulation. Importantly, cardiomyocyte-specific loss of Ecrg4 significantly enriched the differentially expressed proteins in the signaling pathways commonly involved in DOX-induced cardiotoxicity. Our results indicate that Sp1 mediates DOX-induced suppression of Ecrg4, which may contribute indirectly to its cardiotoxicity.

Ikaros Proteins in Tumor: Current Perspectives and New Developments

Ikaros is a zinc finger transcription factor (TF) of the Krüppel family member, which significantly regulates normal lymphopoiesis and tumorigenesis. Ikaros can directly initiate or suppress tumor suppressors or oncogenes, consequently regulating the survival and proliferation of cancer cells. Over recent decades, a series of studies have been devoted to exploring and clarifying the relationship between Ikaros and associated tumors. Therapeutic strategies targeting Ikaros have shown promising therapeutic effects in both pre-clinical and clinical trials. Nevertheless, the increasingly prominent problem of drug resistance targeted to Ikaros and its analog is gradually appearing in our field of vision. This article reviews the role of Ikaros in tumorigenesis, the mechanism of drug resistance, the progress of targeting Ikaros in both pre-clinical and clinical trials, and the potential use of associated therapy in cancer therapy.

Caffeic acid and its derivatives as potential modulators of oncogenic molecular pathways: New hope in the fight against cancer

As a phenolic acid compound, caffeic acid (CA) can be isolated from different sources such as tea, wine and coffee. Caffeic acid phenethyl ester (CAPE) is naturally occurring derivative of CA isolated from propolis. This medicinal plant is well-known due to its significant therapeutic impact including its effectiveness as hepatoprotective, neuroprotective and anti-diabetic agent. Among them, anti-tumor activity of CA has attracted much attention, and this potential has been confirmed both in vitro and in vivo. CA can induce apoptosis in cancer cells via enhancing ROS levels and impairing mitochondrial function. Molecular pathways such as PI3K/Akt and AMPK with role in cancer progression, are affected by CA and its derivatives in cancer therapy. CA is advantageous in reducing aggressive behavior of tumors via suppressing metastasis by inhibiting epithelial-to-mesenchymal transition mechanism. Noteworthy, CA and CAPE can promote response of cancer cells to chemotherapy, and sensitize them to chemotherapy-mediated cell death. In order to improve capacity of CA and CAPE in cancer suppression, it has been co-administered with other anti-tumor compounds such as gallic acid and p-coumaric acid. Due to its poor bioavailability, nanocarriers have been developed for enhancing its ability in cancer suppression. These issues have been discussed in the present review with a focus on molecular pathways to pave the way for rapid translation of CA for clinical use.