Caffeic acid phenethyl ester enhances TRAIL-mediated apoptosis via CHOP-induced death receptor 5 upregulation in hepatocarcinoma Hep3B cells

Recent progress in DNA methyltransferase inhibitors as anticancer agents

DNA methylation mediated by DNA methyltransferase is an important epigenetic process that regulates gene expression in mammals, which plays a key role in silencing certain genes, such as tumor suppressor genes, in cancer, and it has become a promising therapeutic target for cancer treatment. Similar to other epigenetic targets, DNA methyltransferase can also be modulated by chemical agents. Four agents have already been approved to treat hematological cancers. In order to promote the development of a DNA methyltransferase inhibitor as an anti-tumor agent, in the current review, we discuss the relationship between DNA methylation and tumor, the anti-tumor mechanism, the research progress and pharmacological properties of DNA methyltransferase inhibitors, and the future research trend of DNA methyltransferase inhibitors.

AF8c, a Multi-Kinase Inhibitor Induces Apoptosis by Activating DR5/Nrf2 via ROS in Colorectal Cancer Cells

Simple Summary

AF8c, a lapatinib hybrid quinazoline-based EGFR/HER2 inhibitor, was chosen to scrutinize its antiproliferative activity in colorectal cancer (CRC) cells. We found that AF8cinduced apoptosis in CRC cells via diverse mechanisms. In addition to inhibiting the phosphorylation of the ErbB family, AF8c increased the mRNA and protein levels of death receptor 5 (DR5) in vitro and in vivo. In addition, AF8c upregulated several ER stress proteins and the redox-sensitive nuclear respiratory factor 2 alpha subunit (Nrf2) in a p53-dependent manner. We also found that the AF8c-induced increase in the levels of Nrf2, DR5, and apoptosis was diminished by p53 downregulation or knockdown. Furthermore, AF8c showed higher antiproliferative activity than lapatinib in the CRC mouse model in vivo. Therefore, our results suggest AF8c as a highly effective polypharmacological small molecule with an encouraging safety profile, both in vitro and in vivo, for further evaluation as a treatment of CRC.

Abstract

Our team has previously reported a series of quinazoline-based lapatinib hybrids as potent kinase-targeting anticancer agents. Among them, AF8c showed a relatively safe profile in colorectal cancer (CRC) cells. In this study, we delineate a novel anticancer activity of AF8c in CRC cells. AF8c mediated p53-dependent apoptosis of CRC cells via the generation of endoplasmic reticulum (ER) stress and reactive oxygen species (ROS), as well as activation of nuclear respiratory factor 2 alpha subunit (Nrf2) and death receptor 5 (DR5), among others. The silencing of DR5 attenuated the expression levels of Nrf2 and partially inhibited AF8c-induced apoptosis. Additionally, upregulation of Nrf2 by AF8c evoked apoptosis through a decrease in antioxidant levels. Treatment of a CRC mice model with AF8c also resulted in the upregulation of DR5, Nrf2, and CHOP proteins, subsequently leading to a significant decrease in tumor burden. In comparison with lapatinib, AF8c showed higher cellular antiproliferative activity at the tested concentrations in CRC cells and synergized TRAIL effects in CRC cells. Overall, our results suggest that AF8c-induced apoptosis may be associated with DR5/Nrf2 activation through ER stress and ROS generation in CRC cells. These findings indicate that AF8c represents a promising polypharmacological molecule for the treatment of human CRC.

Potential Therapeutic Implications of Caffeic Acid in Cancer Signaling: Past, Present, and Future

Caffeic acid (CA) has been present in many herbs, vegetables, and fruits. CA is a bioactive compound and exhibits various health advantages that are linked with its anti-oxidant functions and implicated in the therapy and prevention of disease progression of inflammatory diseases and cancer. The anti-tumor action of CA is attributed to its pro-oxidant and anti-oxidant properties. CA’s mechanism of action involves preventing reactive oxygen species formation, diminishing the angiogenesis of cancer cells, enhancing the tumor cells’ DNA oxidation, and repressing MMP-2 and MMP-9. CA and its derivatives have been reported to exhibit anti-carcinogenic properties against many cancer types. CA has indicated low intestinal absorption, low oral bioavailability in rats, and pitiable permeability across Caco-2 cells. In the present review, we have illustrated CA’s therapeutic potential, pharmacokinetics, and characteristics. The pharmacological effects of CA, the emphasis on in vitro and in vivo studies, and the existing challenges and prospects of CA for cancer treatment and prevention are discussed in this review.

Potential Therapeutic Implications of Caffeic Acid in Cancer Signaling: Past, Present, and Future

Caffeic acid (CA) has been present in many herbs, vegetables, and fruits. CA is a bioactive compound and exhibits various health advantages that are linked with its anti-oxidant functions and implicated in the therapy and prevention of disease progression of inflammatory diseases and cancer. The anti-tumor action of CA is attributed to its pro-oxidant and anti-oxidant properties. CA’s mechanism of action involves preventing reactive oxygen species formation, diminishing the angiogenesis of cancer cells, enhancing the tumor cells’ DNA oxidation, and repressing MMP-2 and MMP-9. CA and its derivatives have been reported to exhibit anti-carcinogenic properties against many cancer types. CA has indicated low intestinal absorption, low oral bioavailability in rats, and pitiable permeability across Caco-2 cells. In the present review, we have illustrated CA’s therapeutic potential, pharmacokinetics, and characteristics. The pharmacological effects of CA, the emphasis onin vitro and in vivostudies, and the existing challenges and prospects of CA for cancer treatment and prevention are discussed in this review.

Bioactivity-guided Isolation of TRAIL-Resistance-Overcoming Activity Compounds From the Leaves of Murraya exotica

Fractionation of the leaf extract from Murraya exotica led to the successful isolation of 12 compounds (1-12) with TRAIL-resistance-overcoming activity. Xanthinosin (1), 11α, 13-dihydroxanthinin (2), 11β, 13-dihydroxanthinosin (3), 4α, 11α, 13-trihydroxanthuminol (4), desacetylxanthanol (5), and lasidiol p-methoxybenzoate (6) were sesquiterpenes isolated from this plant for the first time, and 3 was isolated from natural sources for the first time. Among them, compounds 1 and 5 showed strong TRAIL-resistance-overcoming activity, but their mechanisms have already been revealed. Furthermore, dihydroxanthinin (2), 1, 5-dicaffeoylquinic acid (7), and (-) loliolide (8), which belong to different phytochemical groups, were investigated for their effects on increasing apoptosis induction to overcome TRAIL resistance using Western blot analysis. The results demonstrated that 2, 7, and 8 promoted TRAIL-induced apoptosis by increasing the expression of several proapoptotic markers, including cleaved caspases −3 and −8, and suppressing anti-apoptotic protein Bcl-2.

Biogenesis, Functions, and Role of CircRNAs in Lung Cancer

CircRNAs, a class of endogenous non-coding RNAs with closed-loop structures, have attracted increasing attention because of their good stability, high specificity of tissue expression, long half-life, and highly conserved sequence. CircRNAs have multiple biological functions, including miRNA sponge, transcription regulator, protein translation, interaction with protein, RNA maturation, and so on. These functions indicate the important role of circRNAs in tumorigenesis and malignant progression and their potential as potent diagnostic biomarkers and therapeutic molecules. In recent years, an increasing body of evidence suggests that circRNAs play a crucial role in proliferation, migration, invasion, and apoptosis of lung cancer cells. Therefore, circRNAs have gradually become a research focus in the diagnosis and treatment of lung cancer patients. This review summarizes the classification, biogenesis, and function of circRNAs, and discusses the role of circRNAs in the diagnosis, prognosis, and treatment of lung cancer patients.

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.

Recent progresses in the pharmacological activities of caffeic acid phenethyl ester

The past decades have seen a growing interest in natural products. Caffeic acid phenethyl ester (CAPE), a flavonoid isolated from honeybee propolis, has shown multiple pharmacological potentials, including anti-cancer, anti-inflammatory, antioxidant, antibacterial, antifungal, and protective effects on nervous systems and multiple organs, since it was found as a potent nuclear factor κB (NF-κB) inhibitor. This review summarizes the advances in these beneficial effects of CAPE, as well as the underlying mechanisms, and proposes that CAPE offers an opportunity for developing therapeutics in multiple diseases. However, clinical trials on CAPE are necessary and encouraged to obtain certain clinically relevant conclusions.

Evaluation of the In Vitro Cytotoxic Activity of Caffeic Acid Derivatives and Liposomal Formulation against Pancreatic Cancer Cell Lines

Pancreatic cancer belongs to the most aggressive group of cancers, with very poor prognosis. Therefore, there is an important need to find more potent drugs that could deliver an improved therapeutic approach. In the current study we searched for selective and effective caffeic acid derivatives. For this purpose, we analyzed twelve compounds and evaluated their in vitro cytotoxic activity against two human pancreatic cancer cell lines, along with a control, normal fibroblast cell line, by the classic MTT assay. Six out of twelve tested caffeic acid derivatives showed a desirable effect. To improve the therapeutic efficacy of such active compounds, we developed a formulation where caffeic acid derivative (7) was encapsulated into liposomes composed of soybean phosphatidylcholine and DSPE-PEG₂₀₀₀. Subsequently, we analyzed the properties of this formulation in terms of basic physical parameters (such as size, zeta potential, stability at 4 °C and morphology), hemolytic and cytotoxic activity and cellular uptake. Overall, the liposomal formulation was found to be stable, non-hemolytic and had activity against pancreatic cancer cells (IC₅₀ 19.44 µM and 24.3 µM, towards AsPC1 and BxPC3 cells, respectively) with less toxicity against normal fibroblasts. This could represent a promising alternative to currently available treatment options.

CircRNA_103762 promotes multidrug resistance in NSCLC by targeting DNA damage inducible transcript 3 (CHOP)

BACKGROUND

CircRNAs have been found to play crucial roles in multiple tumor including non-small cell lung cancer (NSCLC). Here, we researched the correlation between circRNA_103762 and chemotherapy resistance.

METHODS

RT-PCR assay was performed to detect circRNA_103762 and DNA damage inducible transcript 3 (CHOP) expression. CCK8 assay was performed to examine cell proliferation and IC₅₀ of different drug. Migration and invasion assay was used to detect cell migration and invasion.

RESULTS

In our study, circRNA_103762 expression was upregulated in NSCLC tissues and cell. Knockdown of circRNA_103762 can inhibited cell proliferation, migration and invasion in NSCLC. In addition, downregulation of circRNA_103762 promoted CHOP expression and inhibited multidrug resistance (MDR) in NSCLC.

CONCLUSION

Together, we demonstrated that circRNA_103762 is upregulated in NSCLC and functions as an oncogene in NSCLC, and circRNA_103762 enhanced MDR by inhibited CHOP expression in NSCLC cells. These results will help us understand the MDR of NSCLC, providing better effective therapy strategies for patients.

Chemical and Pharmacological Aspects of Caffeic Acid and Its Activity in Hepatocarcinoma

Caffeic acid (CA) is a phenolic compound synthesized by all plant species and is present in foods such as coffee, wine, tea, and popular medicines such as propolis. This phenolic acid and its derivatives have antioxidant, anti-inflammatory and anticarcinogenic activity. In vitro and in vivo studies have demonstrated the anticarcinogenic activity of this compound against an important type of cancer, hepatocarcinoma (HCC), considered to be of high incidence, highly aggressive and causing considerable mortality across the world. The anticancer properties of CA are associated with its antioxidant and pro-oxidant capacity, attributed to its chemical structure that has free phenolic hydroxyls, the number and position of OH in the catechol group and the double bond in the carbonic chain. Pharmacokinetic studies indicate that this compound is hydrolyzed by the microflora of colonies and metabolized mainly in the intestinal mucosa through phase II enzymes, submitted to conjugation and methylation processes, forming sulphated, glucuronic and/or methylated conjugates by the action of sulfotransferases, UDP-glucotransferases, and o-methyltransferases, respectively. The transmembrane flux of CA in intestinal cells occurs through active transport mediated by monocarboxylic acid carriers. CA can act by preventing the production of ROS (reactive oxygen species), inducing DNA oxidation of cancer cells, as well as reducing tumor cell angiogenesis, blocking STATS (transcription factor and signal translation 3) and suppression of MMP2 and MMP-9 (collagen IV metalloproteases). Thus, this review provides an overview of the chemical and pharmacological parameters of CA and its derivatives, demonstrating its mechanism of action and pharmacokinetic aspects, as well as a critical analysis of its action in the fight against hepatocarcinoma.

3‑Bromopyruvate sensitizes human breast cancer cells to TRAIL‑induced apoptosis via the phosphorylated AMPK‑mediated upregulation of DR5

Previous studies have indicated that the sensitivity of breast cancer cells to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis is associated with the expression of death receptors on the cell membrane. However, drug resistance limits the use of TRAIL in cancer therapy. Numerous studies have indicated that death receptors, which induce apoptosis, are upregulated by the endoplasmic reticulum (ER) stress response. 3-Bromopyruvate (3-BP), an anticancer agent, inhibits cell growth and induces apoptosis through interfering with glycolysis. In the present study, it was demonstrated that 3-BP synergistically sensitized breast cancer cells to TRAIL-induced apoptosis via the upregulation of death receptor 5 (DR5). Furthermore, we found that the protein levels of glucose-related protein 78 (GRP78) and CCAAT-enhancer-binding protein homologous protein (CHOP) increased following treatment with 3-BP. The expression of Bax (in MCF-7 cells) and caspase-3 (in MDA-MB-231 cells) increased following co-treatment with 3-BP and TRAIL, whereas the expression of the anti-apoptotic protein Bcl-2 decreased. In order to investigate the molecular mechanism regulating this effect, the expression of adenosine monophosphate-activated protein kinase (AMPK), activated by 3-BP, was determined. It was demonstrated that phosphorylated-AMPK was upregulated following treatment with 3-BP. Notably, Compound C, an AMPK inhibitor, reversed the effects of 3-BP. Finally, a synergistic antitumor effect of 3-BP and TRAIL was observed in MCF-7 cell xenografts in nude mice. In conclusion, these results indicated that 3-BP sensitized breast cancer cells to TRAIL via the AMPK-mediated upregulation of DR5.

Induction of Cell Cycle Arrest and Apoptotic Response of Head and Neck Squamous Carcinoma Cells (Detroit 562) by Caffeic Acid and Caffeic Acid Phenethyl Ester Derivative

Natural polyphenols have been observed to possess antiproliferative properties. The effects, including apoptotic potential of bioactive phenolic compounds, caffeic acid (CA) and its derivative caffeic acid phenethyl ester (CAPE), on cell proliferation and apoptosis in human head and neck squamous carcinoma cells (HNSCC) line (Detroit 562) were investigated and compared. Cancer cells apoptosis rates and cell cycle arrests were analysed by flow cytometry. Exposure to CA and CAPE was found to result in a dose-dependent decrease in the viability of Detroit 562 cells at different levels. CA/CAPE treatment did significantly affect the viability of Detroit 562 cells (MTT results). CAPE-mediated loss of viability occurred at lower doses and was more pronounced, with the concentrations which inhibit the growth of cells by 50% estimated at 201.43 μM (CA) and 83.25 μM (CAPE). Dead Cell Assay with Annexin V labelling demonstrated that CA and CAPE treatment of Detroit 562 cells resulted in an induction of apoptosis at 50 μM and 100 μM doses. The rise of mainly late apoptosis was observed for 100 μM dose and CA/CAPE treatment did affect the distribution of cells in G0/G1 phase. A combination of different phenolic compounds, potentially with chemotherapeutics, could be considered as an anticancer drug.

TRAIL facilitates cytokine expression and macrophage migration during hypoxia/reoxygenation via ER stress-dependent NF-κB pathway

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which is known as a key molecule to induce cancer cell apoptosis, has also been found to participate in the process of ischemia/reperfusion (I/R) injury. Infiltrated macrophages play dual roles in inflammatory injury and healing following I/R. Whether TRAIL has any effect on macrophages during this process remains elusive. Here we showed that I/R triggered the expressions of TRAIL, DR5 and cytokines (IL-1β, TNFα, CCL-2 and ICAM-1), in addition to macrophage infiltration, which could be abolished by TRAIL neutralizing antibody. In vitro, TRAIL enhanced DR5 expression and facilitated the macrophages migration following hypoxia/reoxygenation (H/R) treatment in a dose-dependent manner via ER stress and NF-κB signaling pathways, which is accompanied by inflammatory factors expression. The increased cytokines production (such as TNFα and IL-1β) stimulated by TRAIL can be blocked by the NF-κB and ER stress inhibitor. The results also suggested that NF-κB activation of macrophages during H/R was regulated by ER stress. Thus, our research present that TRAIL affects functional activities of macrophages during I/R injury, which may be a potential therapeutic target for ischemic heart disease.