Resveratrol promotes the sensitivity of small-cell lung cancer H446 cells to cisplatin by regulating intrinsic apoptosis

Resveratrol as a modulatory of apoptosis and autophagy in cancer therapy

Cancer is one of the leading causes of death, with a heavy socio-economical burden for countries. Despite the great advances that have been made in the treatment of cancer, chemotherapy is still the most common method of treatment. However, many side effects, including hepatotoxicity, renal toxicity, and cardiotoxicity, limit the efficacy of conventional chemotherapy. Over recent years, natural products have attracted attention as therapeutic agents against various diseases, such as cancer. Resveratrol (RES), a natural polyphenol occurring in grapes, nuts, wine, and berries, exhibited potential for preventing and treating various cancer types. RES also ameliorates chemotherapy-induced detrimental effects. Furthermore, RES could modulate apoptosis and autophagy as the main forms of cancer cell deaths by targeting various signaling pathways and up/downregulation of apoptotic and autophagic genes. This review will summarize the anti-cancer effects of RES and focus on the fundamental mechanisms and targets for modulating apoptosis and autophagy by RES.

Potential Therapeutic Targets of Resveratrol, a Plant Polyphenol, and Its Role in the Therapy of Various Types of Cancer

Cancer is among the most prominent causes of mortality worldwide. Different cancer therapy modes employed, including chemotherapy and radiotherapy, have been reported to be significant in cancer management, but the side effects associated with these treatment strategies are still a health problem. Therefore, alternative anticancer drugs based on medicinal plants or their active compounds have been generating attention because of their less serious side effects. Medicinal plants are an excellent source of phytochemicals that have been recognized to have health-prompting effects through modulating cell signaling pathways. Resveratrol is a well-known polyphenolic molecule with antioxidant, anti-inflammatory, and health-prompting effects among which its anticancer role has been best defined. Additionally, this polyphenol has confirmed its role in cancer management because it activates tumor suppressor genes, suppresses cell proliferation, induces apoptosis, inhibits angiogenesis, and modulates several other cell signaling molecules. The anticancer potential of resveratrol is recognized in numerous in vivo and in vitro studies. Previous experimental data suggested that resveratrol may be valuable in cancer management or improve the efficacy of drugs when given with anticancer drugs. This review emphasizes the potential role of resveratrol as an anticancer drug by modulating numerous cells signaling pathways in different types of cancer.

The regulation of autophagy by the miR-199a-5p/p62 axis was a potential mechanism of small cell lung cancer cisplatin resistance

BACKGROUND

Autophagy has been found to be involved in the multidrug resistance (MDR) of cancers, but whether it is associated with resistance of small cell lung cancer (SCLC) has not been studied. Here, we hypothesized that a potential autophagy-regulating miRNA, miR-199a-5p, regulated cisplatin-resistant SCLC.

METHODS

We validated the MDR of H446/EP using CCK-8 and LDH. We tested the binding of miR-199a-5p to p62 using the Dual-Luciferase assay and validated the association of miR-199a-5p and p62 in SCLC samples. We overexpressed (OE) and knocked down (KD) miR-199a-5p in H446 and H446/EP and determined the expression of miR-199a-5p, autophagy-related proteins, and the formation of autophagolysosomes using QPCR, western blotting, and MDC staining respectively. These results were validated in an orthotopic H446 mouse model of SCLC.

RESULTS

H446/EP was resistant to cisplatin, etoposide, paclitexal, epirubicin, irinotecan, and vinorelbine. Exposure of cisplatin at 5 μg/ml for 24 h increased LC3II/LC3I, ATG5, p62, and the formation of autophagolysosomes in H446 cells, but not in H446/EP cells. The expression of miR-199a-5p was up-regulated in H446/EP compared to H446. MiR-199a-5p directly targeted the p62 gene. The expression of miR-199a-5p and p62 were correlated in SCLC samples. In H446 and H69PR, the OE of miR-199a-5p increased LC3II/LC3I, p62, and the formation of autophagolysosomes, but not ATG5, while the KD of miR-199a-5p decreased p62, but did not affect LC3II/LC3I, ATG5, and the formation of autophagolysosomes. In H446/EP, the OE of miR-199a-5p decreased p62 only. These results were generally consistent to results in the animal tumor samples.

CONCLUSIONS

The regulation of autophagy by the miR-199a-5p/p62 axis was a potential mechanism of small cell lung cancer cisplatin resistance.

Resveratrol reduces drug resistance of SCLC cells by suppressing the inflammatory microenvironment and the STAT3/VEGF pathway

DNA‐damaging agents, such as doxorubicin (Adriamycin), are widely used for the treatment of small cell lung cancer (SCLC). However, drug resistance is one of the major challenges for treatment of SCLC. Herein, we investigated the mechanisms underlying drug resistance in SCLC cells and the effects of resveratrol (Res) on drug resistance. We report that Adriamycin treatment of H69AR (multidrug resistance phenotype) cells resulted in a lower rate of growth inhibition, up‐regulation of MRP1 and P‐glycoprotein (P‐gp), and higher P‐gp activity as compared with susceptible H69 cells treated with Adriamycin. Moreover, the signal transducer and activator of transcription 3/vascular endothelial growth factor (STAT3/VEGF) pathway was overactivated in H69AR cells, especially after interleukin‐23 treatment. The inflammatory microenvironment promoted the drug resistance of H69AR cells by activating the STAT3/VEGF pathway. The addition of Res suppressed the expression levels of inflammatory mediators, inhibited the STAT3/VEGF pathway, impeded P‐gp activity, and decreased the drug resistance of H69AR cells. H69AR cells exhibited Adriamycin resistance through activation of the STAT3/VEGF pathway, and Res ameliorated the inflammatory microenvironment to suppress the STAT3/VEGF pathway to reduce drug resistance. Our results suggest that Res may have therapeutic potential for SCLC treatment.

Resveratrol increases the sensitivity of breast cancer MDA-MB-231 cell line to cisplatin by regulating intrinsic apoptosis

OBJECTIVES

Breast cancer is one of the most common types of cancer. Chemotherapeutic agents used during treatment induce cytotoxic effects also on normal cells in the tissues. Anti-oxidants used in combination with chemotherapeutic agents have been shown to reduce toxicity on normal cells to a minimum, and some anti-oxidant substances have chemotherapeutic effects. Cisplatin (CDDP) is a platinum class drug that is used clinically in the treatment of many cancers. Resveratrol (RSV) is a natural polyphenol with potent anti-oxidant and anticancer properties. In this study, we aimed to investigate apoptotic effects of using cisplatin and RSV alone or in combined treatment of MDA-MB-231 cells.

MATERIALS AND METHODS

The cytotoxic effects of the drugs on MDA-MB-231 cells were determined by MTT method. Subsequently, the change in CDDP-induced apoptotic effect after RSV addition was examined using the AnnexinV FITC labeling, and TUNEL staining method. Activation of caspase-9, -3 in MDA-MB-231 cells was measured by flow cytometer. The mitochondrial membrane potential (MMP), the major factor on the intrinsic pathway, was measured using flowcytometry.

RESULTS

The combined dose (23 μM CDDP + 72 μM RSV) produced more cytotoxicity than the agents used alone, leading to early apoptosis (8.2%), 31% depolarization, and 23% DNA fragmentation. Caspase-9 was found to be 30.5% in this combined group and caspase-3 was 26.3%.

CONCLUSION

RSV, an effective anti-oxidant, and CDDP as an effective drug in cancer treatment, were found to increase apoptosis when given in the MDA-MB-231 cell.

Medicinal Chemistry Targeting Mitochondria: From New Vehicles and Pharmacophore Groups to Old Drugs with Mitochondrial Activity

Interest in tumor cell mitochondria as a pharmacological target has been rekindled in recent years. This attention is due in part to new publications documenting heterogenous characteristics of solid tumors, including anoxic and hypoxic zones that foster cellular populations with differentiating metabolic characteristics. These populations include tumor-initiating or cancer stem cells, which have a strong capacity to adapt to reduced oxygen availability, switching rapidly between glycolysis and oxidative phosphorylation as sources of energy and metabolites. Additionally, this cell subpopulation shows high chemo- and radioresistance and a high capacity for tumor repopulation. Interestingly, it has been shown that inhibiting mitochondrial function in tumor cells affects glycolysis pathways, cell bioenergy, and cell viability. Therefore, mitochondrial inhibition may be a viable strategy for eradicating cancer stem cells. In this context, medicinal chemistry research over the last decade has synthesized and characterized "vehicles" capable of transporting novel or existing pharmacophores to mitochondrial tumor cells, based on mechanisms that exploit the physicochemical properties of the vehicles and the inherent properties of the mitochondria. The pharmacophores, some of which have been isolated from plants and others, which were synthesized in the lab, are diverse in chemical nature. Some of these molecules are active, while others are prodrugs that have been evaluated alone or linked to mitochondria-targeted agents. Finally, researchers have recently described drugs with well-proven safety and efficacy that may exert a mitochondria-specific inhibitory effect in tumor cells through noncanonical mechanisms. The effectiveness of these molecules may be improved by linking them to mitochondrial carrier molecules. These promising pharmacological agents should be evaluated alone and in combination with classic chemotherapeutic drugs in clinical studies.

Resveratrol inhibits viability and induces apoptosis in the small‑cell lung cancer H446 cell line via the PI3K/Akt/c‑Myc pathway

There have been no major breakthroughs in the treatment of small‑cell lung cancer (SCLC) in recent decades. It is thus essential to explore new or adjuvant treatment options for SCLC. Resveratrol (Res) is a natural antioxidant revealed to influence the entire process of cancer development. Accordingly, the present study used the SCLC cell line H446 to explore the antitumor mechanism of Res. Cells were treated with 40 µg/ml Res with or without pretreatment with the antioxidant N‑acetyl‑L‑cysteine (NAC). H446 cell viability and apoptosis were assessed with MTT and flow cytometry, and the expression of cytochrome c and the PI3K/Akt/c‑Myc pathway and the nuclear translocation of apoptosis inducing factor (AIF) were assessed by western blotting. In addition, the changes in ROS content and mitochondrial membrane potential were determined. The results revealed that Res inhibited H446 cell viability and induced apoptosis, increased cytochrome c expression, inhibited the expression of PI3K/Akt/c‑Myc signaling pathway components, and promoted the translocation of AIF from the cytoplasm to the nucleus in H446 cells. However, NAC pretreatment reversed these changes to various extents. The results of the present study indicated that Res may inhibit the viability and promote the apoptosis of human SCLC H446 cells through the PI3K/Akt/c‑Myc pathway and that oxidative stress and mitochondrial membrane potential depolarization may be involved in the aforementioned processes.

Resveratrol synergizes with cisplatin in antineoplastic effects against AGS gastric cancer cells by inducing endoplasmic reticulum stress‑mediated apoptosis and G2/M phase arrest

Gastric cancer (GC) is a common gastrointestinal malignancy, and cisplatin (DDP) is an important component of chemotherapeutic regimens for GC. However, the application of DDP is limited by its dose-dependent systemic toxicity. Resveratrol (RES) is a natural polyphenol compound that has chemopreventive and therapeutic effects against various cancers, including GC. However, whether RES can sensitize GC cells to DDP remains unknown. Following RES/DDP combination treatment, cell viability was determined by Cell Counting Kit-8 and colony-forming assays, and cell apoptosis and the cell cycle were detected by FITC-Annexin V/PI staining assay and PI staining assay, respectively, followed by flow cytometry. Moreover, western blotting was performed to evaluate the protein expression levels, and the intracellular free Ca²⁺ concentration was determined by a Fluo-4 AM probe after cell cotreatment with RES and DDP. The present results demonstrated that RES/DDP combination treatment significantly inhibited cell viability, promoted cell apoptosis and induced G2/M phase arrest in AGS cells. In addition, it was determined that RES combined with DDP significantly increased the levels of Bax, cleaved poly-ADP-ribose polymerase (PARP), glucose-regulated protein 78 (GRP78), PRKR-like ER kinase (PERK), p-eukaryotic translation initiation factor 2α (p-eIF2α), CCAAT/enhancer binding protein homologous protein (CHOP) and cleaved caspase-12, whereas Bcl-2 expression was downregulated following RES/DDP cotreatment. Moreover, RES/DDP cotreatment significantly upregulated phosphorylated cyclin-dependent kinase 1 (p-CDK1, Tyr15), p21^Waf1/Cip1 and p27^Kip1 protein levels and downregulated Cdc25C protein levels. In conclusion, RES and DDP synergistically inhibited the growth of the gastric adenocarcinoma cell line AGS by inducing endoplasmic reticulum stress-mediated apoptosis and G2/M phase arrest via activation of the PERK/eIF2α/activating transcription factor 4 (ATF4)/CHOP signaling pathway and caspase-12 and by inactivating the CDK1-cyclin B1 complex. These results indicated that RES is a promising adjuvant for DDP during GC chemotherapy.

Natural products and phytochemical nanoformulations targeting mitochondria in oncotherapy: an updated review on resveratrol

Mitochondria are intracellular organelles with two distinct membranes, known as an outer mitochondrial membrane and inner cell membrane. Originally, mitochondria have been derived from bacteria. The main function of mitochondria is the production of ATP. However, this important organelle indirectly protects cells by consuming oxygen in the route of energy generation. It has been found that mitochondria are actively involved in the induction of the intrinsic pathways of apoptosis. So, there have been efforts to sustain mitochondrial homeostasis and inhibit its dysfunction. Notably, due to the potential role of mitochondria in the stimulation of apoptosis, this organelle is a promising target in cancer therapy. Resveratrol is a non-flavonoid polyphenol that exhibits significant pharmacological effects such as antioxidant, anti-diabetic, anti-inflammatory and anti-tumor. The anti-tumor activity of resveratrol may be a consequence of its effect on mitochondria. Multiple studies have investigated the relationship between resveratrol and mitochondria, and it has been demonstrated that resveratrol is able to significantly enhance the concentration of reactive oxygen species, leading to the mitochondrial dysfunction and consequently, apoptosis induction. A number of signaling pathways such as sirtuin and NF-κB may contribute to the mitochondrial-mediated apoptosis by resveratrol. Besides, resveratrol shifts cellular metabolism from glycolysis into mitochondrial respiration to induce cellular death in cancer cells. In the present review, we discuss the possible interactions between resveratrol and mitochondria, and its potential application in cancer therapy.

Resveratrol As A Natural Regulator Of Autophagy For Prevention And Treatment Of Cancer

Resveratrol, as a natural product compound, has been recently attracted much attention for its potent effects on cancer. Cancer is a serious disease threatening human survival and social development. Autophagy is a cellular pathway to realize the metabolic needs of the cell itself and the renewal of some organelles and plays opposing, context-dependent role in tumorigenesis. So the regulation of autophagy is of great significance in the treatment of cancer. p62, as an autophagy adaptor protein, is a preferred target for autophagy and is constantly controlled by constitutive autophagy. As a tumor-suppression mechanism, autophagy deficiency is common in tumors, which results in aberrant accumulation of p62 and activates p62-regulated pathways, such as activation of mTOR in nutrient sensing, and the activation of the Keap1-Nrf2 pathway for antioxidant stress, which are associated with cancer development. In this review, we emphasize that resveratrol can induce autophagy in the treatment of cancer and accelerates the degradation of p62, and then, the mTOR activation is blocked and Nrf2 activation is suppressed. As a result, the multidrug resistance of cancer cells can be reversed by resveratrol.

Molecular Insights into Potential Contributions of Natural Polyphenols to Lung Cancer Treatment

Naturally occurring polyphenols are believed to have beneficial effects in the prevention and treatment of a myriad of disorders due to their anti-inflammatory, antioxidant, antineoplastic, cytotoxic, and immunomodulatory activities documented in a large body of literature. In the era of molecular medicine and targeted therapy, there is a growing interest in characterizing the molecular mechanisms by which polyphenol compounds interact with multiple protein targets and signaling pathways that regulate key cellular processes under both normal and pathological conditions. Numerous studies suggest that natural polyphenols have chemopreventive and/or chemotherapeutic properties against different types of cancer by acting through different molecular mechanisms. The present review summarizes recent preclinical studies on the applications of bioactive polyphenols in lung cancer therapy, with an emphasis on the molecular mechanisms that underlie the therapeutic effects of major polyphenols on lung cancer. We also discuss the potential of the polyphenol-based combination therapy as an attractive therapeutic strategy against lung cancer.

Leveraging the Cardio-Protective and Anticancer Properties of Resveratrol in Cardio-Oncology

Cardio-oncology is a clinical/scientific discipline which aims to prevent and/or treat cardiovascular diseases in cancer patients. Although a large number of cancer treatments are known to cause cardiovascular toxicity, they are still widely used because they are highly effective. Unfortunately, therapeutic interventions to prevent and/or treat cancer treatment-induced cardiovascular toxicity have not been established yet. A major challenge for such interventions is to protect the cardiovascular system without compromising the therapeutic benefit of anticancer medications. Intriguingly, the polyphenolic natural compound resveratrol and its analogs have been shown in preclinical studies to protect against cancer treatment-induced cardiovascular toxicity. They have also been shown to possess significant anticancer properties on their own, and to enhance the anticancer effect of other cancer treatments. Thus, they hold significant promise to protect the cardiovascular system and fight the cancer at the same time. In this review, we will discuss the current knowledge regarding the cardio-protective and the anticancer properties of resveratrol and its analogs. Thereafter, we will discuss the challenges that face the clinical application of these agents. To conclude, we will highlight important gaps of knowledge and future research directions to accelerate the translation of these exciting preclinical findings to cancer patient care.