Resveratrol potentially increased the tumoricidal effect of doxorubicin on SKOV3 cancer stem cells in vitro

Advances in the role of resveratrol and its mechanism of action in common gynecological tumors

The incidence of common gynecological malignancies remains high, with current treatments facing multiple limitations and adverse effects. Thus, continuing the search for safe and effective oncologic treatment strategies continues. Resveratrol (RES), a natural non-flavonoid polyphenolic compound, is widely found in various plants and fruits, such as grapes, Reynoutria japonica Houtt., peanuts, and berries. RES possesses diverse biological properties, including neuroprotective, antitumor, anti-inflammatory, and osteoporosis inhibition effects. Notably, RES is broadly applicable in antitumor therapy, particularly for treating gynecological tumors (cervical, endometrial, and ovarian carcinomas). RES exerts antitumor effects by promoting tumor cell apoptosis, inhibiting cell proliferation, invasion, and metastasis, regulating tumor cell autophagy, and enhancing the efficacy of antitumor drugs while minimizing their toxic side effects. However, comprehensive reviews on the role of RES in combating gynecological tumors and its mechanisms of action are lacking. This review aims to fill this gap by examining the RES antitumor mechanisms of action in gynecological tumors, providing valuable insights for clinical treatment.

Cytotoxic activity and cell specificity of a novel LHRH peptide drug conjugate, D-Cys6-LHRH vedotin, against ovarian cancer cell lines

Ovarian cancer is the most deadly female gynaecological malignancy in developed countries and new treatments are urgently needed. The luteinising hormone releasing hormone (LHRH) peptide drug conjugate Zoptarelin doxorubicin is one such potential new drug modality that entered clinical trials for treating LHRH receptor-positive gynaecological cancers. However, development stopped after disappointing Phase 3 results in 2017. We believe the lack of efficacy was due to linker instability and payload potency. In this work, we replaced its linker-toxin with vedotin (MC-VC-PABC-MMAE), yielding the novel peptide drug conjugate D-Cys6-LHRH vedotin. A GI50 and cell specificity comparison against cancerous and non-cancerous ovarian cell lines showed significantly superior bioactivity and selectivity over Zoptarelin doxorubicin (GI50 4 vs. 453 nM) and other chemotherapeutic drugs used for treating ovarian cancers. Our results suggest D-Cys6-LHRH vedotin can potentially be used as a treatment for ovarian cancer.

Resveratrol: Targeting Cancer Stem Cells and ncRNAs to Overcome Cancer Drug Resistance

A major challenge in treating cancer is the development of drug resistance, which can result in treatment failure and tumor recurrence. Targeting cancer stem cells (CSCs) and non-coding RNAs (ncRNAs) with a polyphenolic substance called resveratrol has the ability to combat this problem by lowering cancer resistance to drugs and opening up new therapeutic options. Resveratrol alters the expression of genes related to self-renewal, modulating important signaling pathways involved in cancer initiation and CSC control. Additionally, resveratrol affects non-coding RNAs (ncRNAs), including Micro-RNAs (miRNAs) and long non-coding RNAs (lncRNAs which are essential for stemness, drug resistance, and other cancer-related activities. Numerous studies have shown that resveratrol has the potential to be an effective anticancer drug when used in combination therapy, but issues with absorption and pharmacokinetics still need to be resolved before it can be used in clinical applications. Reducing chemotherapy resistance by better understanding the intricate mechanisms by which resveratrol affects cancer cells and CSCs, as well as its impact on ncRNA expression, could eventually contribute to more effective cancer treatments. To completely understand these pathways and optimize the utilization of resveratrol in combination treatments, additional study is necessary.

Ganoderma lucidum extract promotes tumor cell pyroptosis and inhibits metastasis in breast cancer

Regulation of tumor cell death is a fundamental mechanism for tumor treatment. However, most tumors are resistant to cell death. Triggering inflammatory cell death, pyroptosis, may provide a new view of enhancing tumor cell death. Here we report a new role of Ganoderma lucidum extract (GLE) in pyroptotic cell death. Treatment with GLE (50-200 μg/mL) significantly elevated reactive oxygen species (ROS) levels and caused pyroptotic cell death in breast cancer cells. Mechanistically, GLE activates caspase 3 and further cleaves the gasdermin E (GSDME) protein to form pores on the cell membrane, releasing massive amounts of inflammatory factors in breast cancer cells. We also showed that GLE enhanced antitumor immune responses by substantially increasing the subsets of natural killer (NK) and CD8⁺T cells in the peripheral immune system and tumor microenvironment. In addition, GLE destroys multiple steps of tumor metastasis, including adhesion, migration, invasion, colonization, and angiogenesis. Collectively, these results suggest that GLE provides a potential approach for breast cancer treatment, which may complement chemotherapy or immunotherapy for cancer metastasis.

Natural bioactive compounds-doxorubicin combinations targeting topoisomerase II-alpha: Anticancer efficacy and safety

Cancer is one of the leading causes of death worldwide, so pursuing effective and safe therapeutics for cancer is a key research objective nowadays. Doxorubicin (DOX) is one of the commonly prescribed chemotherapeutic agents that has been used to treat cancer with its antimitotic properties via inhibition of topoisomerase II (TOP2) activity. However, many problems hinder the broad use of DOX in clinical practice, including cardiotoxicity and drug resistance. Research in drug discovery has confirmed that natural bioactive compounds (NBACs) display a wide range of biological activities correlating to anticancer outcomes. The combination of NBACs has been seen to be an ideal candidate that might increase the effectiveness of DOX therapy and decreases its unfavorable adverse consequences. The current review discusses the chemo-modulatory mechanism and the protective effects of combined DOX with NBACs with a binding affinity (pKi) toward TOP2A more than pKi of DOX. This review will also discuss and emphasize the molecular mechanisms to provide a pathway for further studies to reveal other signaling pathways. Taken together, understanding the fundamental mechanisms and implications of combined therapy may provide a practical approach to battling cancer diseases.

Sunitinib Reduced the Migration of Ectopic Endometrial Cells via p-VEGFR-PI3K-AKT-YBX1-Snail Signaling Pathway

Endometriosis (EMs) is one of the most common gynecological diseases, lacking effective treatment. EMs are currently being treated with small molecule targeted therapy, which has resulted in a significant reduction in patient suffering. Our previous studies have shown that sunitinib plays an obvious role in migration. Consequently, the purpose of this study is to explore the molecular mechanism by which sunitinib suppressed the ectopic endometrial migration. The ectopic endometrial cells from patients were divided into two groups: the control group and the sunitinib group. Co-IP and protein spectrum assay were employed to filtrate differential proteins between two groups, and then, our study discovered a signaling pathway, p-VEGFR-PI3K-AKT-YBX1-Snail, in the cell of EMs. To confirm this signaling pathway, VEGF165 was added to the sunitinib group to upregulate the expression of VEGFR. Next, the expression of p-VEGFR, PI3K, AKT, YBX1, and snail was measured in the control group and sunitinib group (compared with the control group: p-VEGFR, PI3K, AKT, YBX1, and snail, $\ast \ast \ast \ast P<0.0001$ ) and the VEGFR+sunitinib group (compared with the sunitinib group: p-VEGFR, PI3K, AKT, and snail, $\ast \ast \ast \ast P<0.0001$ ; YBX1, $\ast \ast \ast P<0.001$ ); finally, the outcome was as expected. In addition to in vitro experiments, we also conducted in vivo experiments in mice. In the EMs mouse model, we found sunitinib reduced the number of heterotopic foci ( $t=11.16$ , $\ast \ast \ast \ast P<0.0001$ ) and inhibited the expression of p-VEGFR, YBX1, and snail by immunofluorescence. To sum up, sunitinib exactly reduced the migration of ectopic endometrial cells with the involvement of the p-VEGFR-PI3K-AKT-YBX1-Snail signaling pathway in both in vitro and in vivo experiments. This study suggests that sunitinib presents a potential targeted drug for EMs therapy.

Additive effects of resveratrol and doxorubicin on bladder cancer cells

The treatment of bladder cancer remains a challenge in clinical practice. Different chemotherapeutic protocols can be used; however, it is common to observe tumor recurrence and secondary effects that result in toxicity. Doxorubicin (DOX), one of the most effective anticancer agents used to treat bladder cancer, can cause chronic cardiotoxicity, limiting its use in clinical practice. Resveratrol (RES), a natural product with potential antitumor activity against bladder cancer, is associated with rapid metabolism and low bioavailability and needs to be combined with chemotherapeutic drugs to improve its use. Our study aimed to assess the therapeutic effect of a low concentration of DOX (2 µM) in combination with RES (150, 200 and 250 µM) on two bladder cancer cell lines. We investigated the mechanism of interaction between the drugs by performing cytotoxicity, clonogenic, oxidative stress, cell migration, cell morphology and nuclear division index (NDI) assays. Cytotoxicity evaluation revealed an additive interaction between RES and DOX for both cell lines. Additionally, the results of cell colony formation, oxidative stress, cell migration, cell morphology and NDI assays showed that a combination of DOX and RES was more effective than RES or DOX alone. In conclusion, a low concentration of DOX combined with RES could potentiate the antitumor effects of the drugs on bladder cancer cells, thus overcoming the secondary effects caused by DOX and the low bioavailability of resveratrol.

Targeting cancer stem cells by nutraceuticals for cancer therapy

Accumulating evidence has demonstrated that cancer stem cells (CSCs) play an essential role in tumor progression and reoccurrence and drug resistance. Multiple signaling pathways have been revealed to be critically participated in CSC development and maintenance. Emerging evidence indicates that numerous chemopreventive compounds, also known as nutraceuticals, could eliminate CSCs in part via regulating several signaling pathways. Therefore, in this review, we will describe the some natural chemopreventive agents that target CSCs in a variety of human malignancies, including soy isoflavone, curcumin, resveratrol, tea polyphenols, sulforaphane, quercetin, indole-3-carbinol, 3,3'-diindolylmethane, withaferin A, apigenin, etc. Moreover, we discuss that eliminating CSCs by nutraceuticals might be a promising strategy for treating human cancer via overcoming drug resistance and reducing tumor reoccurrence.

Natural products targeting cancer stem cells: Implications for cancer chemoprevention and therapeutics

Cancer, being the leading cause of death in the globe, has been one of the major thrust areas of research worldwide. In a new paradigm about neoplastic transformations, the initiation and recurrence of disease is attributed to few mutated cells in bulk of tumor called cancer stem cells (CSCs). CSCs have capacity of self-renewal and differentiation, which are known for resistance to radio and chemotherapy leading to recurrence of the disease even after treatment. Most of traditional drugs implicated in cancer therapy targeting primary tumors have substantial toxicity to the physiological system and have not been efficient in targeting these CSCs leading to poor prognosis. Targeting these CSCs in bulk of tumor might be novel strategy for cancer chemoprevention and therapeutics. Diet-derived interventions and diverse natural products are known to target these CSCs and related signaling pathways, namely, Wnt, Notch, and Hedgehog pathways, which are implicated for CSC self-renewal. PRACTICAL APPLICATIONS: Cancer remains a global challenge even in this century. Poor prognosis, survival rate, and recurrence of the disease have been the major concerns in traditional cancer therapy regimes. Targeting cancer stem cells might be novel strategy for elimination and cure of the chronic disease as they are known to modulate all stages of carcinogenesis and responsible for recurrence and resistance to chemotherapy and radiotherapy. The evidence support that natural products might inhibit, delay, or reverse the process of tumorigenesis and modulate the different signaling pathways implicated for cancer stem cells self-renewal and differentiation. Natural products have minimal toxicity compared to traditional cancer therapy drugs since they have long been utilized in our food habits without any major side effects reported. Thus, targeting cancer stem cells with natural product might be a novel strategy for drug development in cancer chemoprevention and therapeutics.

Salinomycin Modulates the Expression of mRNAs and miRNAs Related to Stemness in Endometrial Cancer

BACKGROUND

Salinomycin, an ionophore antibiotic, has a strong anti-cancer effect, inducing the apoptosis of cancer cells and cancer stem cells.

OBJECTIVE

The aim of the study was to assess the influence of salinomycin on the expression profile of genes related to stemness and miRNA regulating their expression in endometrial cancer cells.

METHODS

Endometrial cancer cells of cell line Ishikawa were exposed to salinomycin at concentrations in the range of 0.1-100 μM, with the aim of determining its pro-apoptotic potential and the concentration which would cause the death of 50% of the cells (Sulforhodamine B test). In the following stages, the cells were incubated with the drug at a concentration of 1μM for 12,24 and 48 hour periods and compared to the control. Determining the changes in the expression of the genes related to stemness and regulating their miRNA was done using the microarray technique and RTqPCR. ELISA assay was performed in order to determine the level of TGFβ2, COL14A1, CDH2, WNT5A in cell culture under salinomycin treatment in comparison to the control.

RESULTS

Salinomycin caused the apoptosis of cells. For the concentration of 0.1 μM, a decrease in the population of living cells by 11.9% was determined. For 1 μM, it was 49.8%, for 10 μM -69.4%, and for a concentration of 100 μM - 87.9%. The most noticeable changes in the expression caused by the addition of salinomycin into the culture were noted for mRNA: TGFβ2; WNT5A (up-regulated); COL14A1; CDH2 (down-regulated), as well as miRNA: hsa-miR-411 (up-regulated); hsa-miR-200a; hsa-miR-33a; hsa-miR-199a; hsa-miR-371-5p; hsa-miR-374; hsa-miR-374b (down-regulated).

CONCLUSION

It was confirmed that salinomycin has an influence on the stemness process. The most noticeable changes in the expression were noted for mRNA: TGFβ2; COL14A1; CDH2; WNT5A, as well as for miRNA: hsa-miR-200a; hsa-miR-33a; hsa-miR-199a; hsa-miR-371-5p; hsa-miR-411; hsa-miR- 374a; hsa-miR-374b.

Sinomenine inhibits hypoxia induced breast cancer side population cells metastasis by PI3K/Akt/mTOR pathway

Sinomenine is an alkaloid derived from Chinese medicinal plant Sinomenium acutum. Our previous studies suggested that sinomenine can inhibit the metastasis of breast cancer. However, whether sinomenine can inhibit the metastasis characteristics of breast cancer side population (SP) cells is still unknown. In present study, we isolated the side population (SP) cells from MDA-MB-231 cells by fluorescence-activated cell sorting (FACS). MDA-MB-231 SP cells were treated with different concentrations of sinomenine at the absence or presence of hypoxia, and cell viability were measured by CCK-8 assay. The transwell invasive assay were conducted to assess of the effect of sinomenine on the invasion of hypoxic MDA-MB-231 SP cells. The protein expression was detected by Western blot assay. Sinomenine inhibited the cell viability and invasion of hypoxic MDA-MB-231 SP cells. Western blot assay results showed that the upregulation of MMP-2 and MMP-9 by hypoxia was inversed by sinomenine. Additionally, it was found that sinomenine suppressed the activation of PI3K/Akt/mTOR pathway under hypoxia in MDA-MB-231 SP cells. Moreover, the inhibiton of sinomenine on metastasis of hypoxic MDA-MB-231SP cells and PI3K/Akt/mTOR pathway could be rescued by PI3K activator IGF-1. Our study suggested that sinomenine inhibits invasion of breast cancer SP cells under hypoxia through PI3K/Akt/mTOR pathway.

Resveratrol, cancer and cancer stem cells: A review on past to future

Cancer remains to be an unresolved medical challenge despite of tremendous advancement in basic science research and clinical medicine. One of the major limitations is due to the side effects of chemotherapy which remains to be palliative without offering any permanent cure for cancer. Cancer stem cells (CSCs) are the subpopulation of cells in tumors that remain viable even after surgery, chemo- and radio-therapy that eventually responsible for tumor relapse. Hence, by eliminating non-stem cancer cells and cancer stem cells from the patient, permanent cure is expected. Phytochemicals have been under the intensive study to target these CSCs effectively and permanently as they do not cause any side effects. Resveratrol (RSV) is one such compound attaining lot of interest in recent days to target CSCs either alone or in combination. RSV has been used by several researchers to target cancer cells in a variety of disease models, however its CSC targeting abilities are under intensive study at present. This review is to summarize the effects of RSV under in vitro and in vivo conditions along with advantages and disadvantages of its uses against cancer cells and cancer stem cells. From the first reports on phytochemical applications against cancer and cancer stem cells in 1997 and 2002 respectively followed by later reports, up to date observations and developments are enlisted from PubMed in this comprehensive review. RSV is shown to be a potential compound having impact on altering the signal transduction pathways in cancer cells. However, the effects are variable under in vitro and in vivo conditions, and also with its use alone or in combination with other small molecules. Past research on RSV is emphasizing the importance of in vivo experimental models and clinical trials with different prospective combinations, is a hope for future promising treatment regimen.

Estradiol modulated colorectal cancer stem cells bioactivity and interaction with endothelial cells

This study aimed to evaluate the modulatory role of sex-related hormone estradiol on cancer stem cells with the origin of colorectal adenocarcinoma in vitro. Cancer stem cells were incubated with 100 nM estradiol for 48 h. The cell survival rate was analyzed using the MTT assay. Immunocytochemistry staining of Ki-67 and Inhibin and Apoptosis PCR array were done to measure proliferation/apoptosis. Cell migration was monitored via the Transwell Migration assay. The expression of exosome biogenesis genes was measured using a real-time PCR assay. The fatty acid profile was monitored using gas chromatography. The level of FAK, SQSTM1, ER, and SIRT1 was examined using Western blotting. Cancer stem-endothelial cell interaction was investigated using Surface Plasmon Resonance assay. Data showed no significant differences in cancer stem cell viability and proliferation between control and estradiol-treated groups (p>0.05). PCR array highlighted the up-regulation of both pro- and anti-apoptosis effectors in the treatment group compared to the control cells (p<0.05). Cell migration capacity was increased after treatment with estradiol (p<0.001). Both exocytosis and exosome biogenesis were decreased in cancer stem cells exposed to estradiol (p<0.05). Data showed the reduction of palmitic acid, and increase of Palmitoleic and Linolenic acids in estradiol-treated cells. Estrogen induced estrogen receptor, SQSTM1 proteins and decreased SIRT1 factor after 48 h. Surface Plasmon Resonance revealed the suppression of cancer stem-endothelial cell interaction and affinity. Estradiol could change the migration, juxtacrine and paracrine activities of cancer stem cells, showing the importance of sex-related hormones in the dynamic of cancer development.

Gomisin M2 from Baizuan suppresses breast cancer stem cell proliferation in a zebrafish xenograft model

Gomisin M2 isolated from Schisandra viridis A. C. Smith has potential anti-tumor effects on certain cancers, including breast cancer. However, only a few investigations have been conducted on the effects of Gomisin M2 on breast cancer stem cells (CSCs), which have the ability to self-renew and differentiate, as a possible strategy to resolve cancer cell resistance to apoptosis and to improve treatments. It is essential to investigate the effects of Gomisin M2 on breast cancer stem cells (BCSCs). In this study, we enriched breast cancer stem cells with CD44+/CD24- from MDA-MB-231 and HCC1806 cells through magnetic-activated cell sorting and cultured these in serum-free medium. The ability of Gomisin M2 to kill breast cancer stem cells was evaluated in vitro and in vivo. Gomisin M2 significantly inhibited the proliferation of the triple-negative breast cancer cell lines and mammosphere formation in breast CSCs and downregulated the Wnt/β-catenin self-renewal pathway. Moreover, Gomisin M2 induced apoptosis and blocked the mitochondrial membrane potential of BCSCs. Gomisin M2 suppressed the proliferation of MDA-MB-231 and HCC1806 xenografts in zebrafish. Together, these findings suggest that the anti-BCSC activity of Gomisin M2 could become a promising starting point for the discovery of novel BCSC-targeting drugs.

Quercetin Enhances the Anti-Tumor Effects of BET Inhibitors by Suppressing hnRNPA1

Bromodomain and extraterminal domain (BET) proteins, which are important epigenetic readers, are often dysregulated in cancer. While a number of BET inhibitors are currently in early phase clinical trials, BET inhibitors show limited single-agent activity. The purpose of this study is to determine if Quercetin, a naturally occurring polyphenolic flavonoid often found abundant in fruits and vegetables, can enhance the anti-tumor effects of BET inhibitors. The efficacy of the combination was evaluated in vitro and in a xenograft model of pancreatic cancer. Co-treatment with BET inhibitors and Quercetin promoted apoptosis, decreased sphere-forming ability by cancer cells, and decreased cell proliferation. We found that hnRNPA1, a nuclear protein known to control mRNA export and mRNA translation of anti-apoptotic proteins, mediates some anti-tumor effects by Quercetin. Additionally, we show that combining BET inhibitors with Quercetin or hnRNPA1 knockdown decreased the anti-apoptotic protein Survivin. Significantly, Quercetin decreased hnRNPA1 in vivo and enhanced the effects of BET inhibitors at suppressing tumor growth. Together, these results demonstrate that Quercetin enhances the efficacy of BET inhibitors by suppressing hnRNPA1, and identify combination therapy with Quercetin and BET inhibitors for the treatment of cancer patients.

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.

Pinostrobin inhibits proliferation and induces apoptosis in cancer stem-like cells through a reactive oxygen species-dependent mechanism

Current treatments and targeted therapies for malignancies are limited due to their severe toxicity and the development of resistance against such treatments, which leads to relapse. Past evidence has indicated that a number of plant-derived dietary agents possess biological activity against highly tumorigenic and resistant cell populations associated with cancer relapse. These subpopulations, termed cancer stem-like cells (CSCs), have been targeted with plant-derived dietary flavonoids. The present study was undertaken to assess the anti-proliferative potential of pinostrobin, a dietary flavonoid, against CSCs. Sphere-forming cells were developed from HeLa cell lines using specific culture conditions. The existence of a CSC population was confirmed by the morphological examination and analysis of surface markers using confocal microscopy and flow cytometry. The effect of pinostrobin on the cell viability of the CSC population, evaluated through MTT reduction assays and the expression levels of surface markers (CD44⁺ and CD24⁺), was studied through various biological assays. HeLa-derived CSCs showed higher CD44⁺ and lower CD24⁺ expression. Pinostrobin inhibited the self-renewal capacity and sphere formation efficiency of CSCs in a dose-dependent manner. Increased ROS production, and decreased mitochondrial membrane potential and CD44⁺ expression indicated that pinostrobin promoted ROS-mediated apoptosis in CSCs. These results thus demonstrate the therapeutic potential and effectiveness of pinostrobin in the chemoprevention and relapse of cancer by targeting the CSC population. Thus, pinostrobin, in combination with currently available chemo and radiation therapies, could possibly be used as a safe strategy to alleviate adverse treatment effects, together with enhancing the efficacy.

The anti-proliferative potential of pinostrobin, a dietary flavonoid, is evaluated against cancer stem-like cells.