Targeting β-Catenin Signaling by Natural Products for Cancer Prevention and Therapy

The recent update and advancements of natural products in targeting the Wnt/β-Catenin pathway for cancer prevention and therapeutics

The Wnt/β-Catenin pathway (Wnt/β-CatP) is implicated in accelerating carcinogenesis and cancer progression, contributing to increased morbidity and treatment resistance. Even though it holds promise as a focus for cancer treatment, its intricate nature and diverse physiological effects pose significant challenges. Recent years have witnessed significant advancements in this domain, with numerous natural products demonstrating promising preclinical anti-tumor effects and identified as inhibitors of the Wnt/β-CatP through various upstream and downstream mechanisms. This study provides a comprehensive overview of the current landscape of Wnt/β-Cat-targeted cancer therapy, examining the impact of natural products on Wnt/β-Cat signaling in both cancer prevention and therapeutic contexts. A comprehensive search was conducted on scientific databases like SciFinder, PubMed, and Google Scholar to retrieve relevant literature on Wnt-signaling, natural products, β-Catenin (β-Cat), and cancer from 2020 to January 2024. As per the analysis of the relevant reference within the specified period, it has been noted that a total of 58 phytoconstituents, predominantly phenolics, followed by triterpenoids and several other classes, along with a limited number of plant extracts, have exhibited activity targeting the Wnt/β-CatP. Most β-Cat regulating modulators restrict cancer cell development by suppressing β-Cat expression, facilitating proteasomal degradation, and inhibiting nuclear translocation. Multiple approaches have been devised to block the activity of β-Cat in cancer therapy, a key factor in cancer progression, leading to the discovery of various Wnt/β-CatP regulators. However, their exploration remains limited, necessitating further research using clinical models for potential clinical use in cancer prevention and therapeutics.

Pterostilbene-Isothiocyanate Inhibits Proliferation of Human MG-63 Osteosarcoma Cells via Abrogating β-Catenin/TCF-4 Interaction-A Mechanistic Insight

Osteosarcoma, a highly metastasizing bone neoplasm, is a leading cause of death and disability in children and adolescents worldwide. Osteosarcoma is only suboptimally responsive to surgery and radio- and chemotherapy, that too with adverse side effects. Hence, there is a necessary need for safer alternative therapeutic approaches. This study evaluated the anticancer effects of the semi-synthetic compound, pterostilbene-isothiocyanate (PTER-ITC), on human osteosarcoma MG-63 cells through cytotoxicity, wound-healing, and transwell-migration assays. Results showed that PTER-ITC specifically inhibited the survival, proliferation, and migration of osteosarcoma cells. PTER-ITC induced apoptosis in MG-63 cells by disrupting mitochondrial membrane potential, as evident from the outcomes of different cytological staining. The antimetastatic potential of PTER-ITC was evaluated through immunostaining, RT-qPCR, and immunoblotting. In silico (molecular docking and dynamic simulation) and, subsequently, biochemical [co-immunoprecipitation (Co-IP) and luciferase reporter] assays deciphered the underlying mode-of-action of this compound. PTER-ITC increased E-cadherin and reduced N-cadherin levels, thereby facilitating the reversal of epithelial-mesenchymal transition (EMT). It also modulated the expressions of proliferative cell nuclear antigen (PCNA), caspase-3, poly [ADP-ribose] polymerase (PARP-1) and matrix metalloproteinase-2/9 (MMPs-2/9) at transcriptional and translational levels. PTER-ITC interfered with the β-catenin/transcription factor-4 (TCF-4) interaction in silico by occupying the β-catenin binding site on TCF-4, confirmed by their reduced physical interactions (Co-IP assay). This inhibited transcriptional activation of TCF-4 by β-catenin (as shown by luciferase reporter assay). In conclusion, PTER-ITC exhibited potent anticancer effects in vitro against human osteosarcoma cells by abrogating the β-catenin/TCF-4 interaction. Altogether, this study suggests that PTER-ITC may be regarded as a new approach for osteosarcoma treatment.

β-Sitosterol blocks the LEF-1-mediated Wnt/β-catenin pathway to inhibit proliferation of human colon cancer cells

OBJECTIVES

This study aimed to investigate the LEF-1-mediated Wnt/β-catenin pathway for its biological functions and prognostic value in colon cancer (CC). Furthermore, the potential molecular mechanism of β-sitosterol in CC was investigated in vitro.

METHODS

Clinical information and gene expression profiles from CC patients were obtained based on Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. In addition, we applied R software "Limma" package for the differential analysis of LEF-1 between cancer and para-carcinoma tissue samples. Kaplan-Meier (KM) survival analysis was adopted for analyzing whether LEF-1 was of prognostic significance. Moreover, gene set enrichment analysis (GSEA) was adopted for pathway enrichment analysis and visualization. In addition, CCK8, plate cloning, scratch and high-content screening (HCS) imaging assays were performed to examine the therapeutic efficacy of β-sitosterol in human CC HCT116 cells. siRNA technology was employed to knock down LEF1 expression in HCT116 cells. qRT-PCR and Western-blot (WB) analysis were carried out to analyze the HCT-116 mRNA and protein expression levels, respectively.

RESULTS

LEF-1 was up-regulated within CC and acted as an oncogenic gene. LEF-1 up-regulation predicted the dismal prognostic outcome and activated the Wnt/β-catenin pathway. β-sitosterol effectively suppressed HCT116 cells proliferation and invasion. For the mechanism underlying β-sitosterol, β-sitosterol was found to significantly down-regulate LEF-1 gene and protein expression and disrupt Wnt/β-catenin pathway transmission in HCT116 cells. After suppressing LEF-1 expression, its downstream targets including C-myc, Survivin and CCND1 were also down-regulated.

CONCLUSION

According to our results, LEF-1 down-regulation can effectively block Wnt/β-catenin pathway, inhibit CC cell growth and migration. Collectively, β-sitosterol can be used to treat CC, which can provide anti-tumor activity by targeting LEF-1.

In Vitro and In Silico Study on the Impact of Chlorogenic Acid in Colorectal Cancer Cells: Proliferation, Apoptosis, and Interaction with β-Catenin and LRP6

Colorectal cancer mortality rate and highly altered proteins from the Wnt/β-catenin pathway increase the scientific community's interest in finding alternatives for prevention and treatment. This study aims to determine the biological effect of chlorogenic acid (CGA) on two colorectal cancer cell lines, HT-29 and SW480, and its interactions with β-catenin and LRP6 to elucidate a possible modulatory mechanism on the Wnt/β-catenin pathway. These effects were determined by propidium iodide and DiOC6 for mitochondrial membrane permeability, MitoTracker Red for mitochondrial ROS production, DNA content for cell distribution on cell cycle phases, and molecular docking for protein-ligand interactions and binding affinity. Here, it was found that CGA at 2000 µM significantly affects cell viability and causes DNA fragmentation in SW480 cells rather than in HT-29 cells, but in both cell lines, it induces ROS production. Additionally, CGA has similar affinity and interactions for LRP6 as niclosamide but has a higher affinity for both β-catenin sites than C2 and iCRT14. These results suggest a possible modulatory role of CGA over the Wnt/β-catenin pathway in colorectal cancer.

Lessons learned from the discovery and development of the sesquiterpene lactones in cancer therapy and prevention

INTRODUCTION

Sesquiterpene lactones (SLs) are one of the most diverse bioactive secondary metabolites found in plants and exhibit a broad range of therapeutic properties . SLs have been showing promising potential in cancer clinical trials, and the molecular mechanisms underlying their anticancer potential are being uncovered. Recent evidence also points to a potential utility of SLs in cancer prevention.

AREAS COVERED

This work evaluates SLs with promising anticancer potential based on cell, animal, and clinical models: Artemisinin, micheliolide, thapsigargin dehydrocostuslactone, arglabin, parthenolide, costunolide, deoxyelephantopin, alantolactone, isoalantolactone, atractylenolide 1, and xanthatin as well as their synthetic derivatives. We highlight actionable molecular targets and biological mechanisms underlying the anticancer therapeutic properties of SLs. This is complemented by a unique assessment of SL mechanisms of action that can be exploited in cancer prevention. We also provide insights into structure-activity and pharmacokinetic properties of SLs and their potential use in combination therapies.

EXPERT OPINION

We extract seven major lessons learned and present evidence-based solutions that can circumvent some scientific limitations or logistic impediments in SL anticancer research. SLs continue to be at the forefront of cancer drug discovery and are worth a joint interdisciplinary effort in order to leverage their potential in cancer therapy and prevention.

Modulatory Effect of Chlorogenic Acid and Coffee Extracts on Wnt/β-Catenin Pathway in Colorectal Cancer Cells

The Wnt/β-Catenin pathway alterations present in colorectal cancer (CRC) are of special interest in the development of new therapeutic strategies to impact carcinogenesis and the progression of CRC. In this context, different polyphenols present in natural products have been reported to have modulatory effects against the Wnt pathway in CRC. In this study, we evaluate the effect of two polyphenol-rich coffee extracts and chlorogenic acid (CGA) against SW480 and HT-29 CRC cells. This involved the use of MTT and SRB techniques for cell viability; wound healing and invasion assay for the evaluation of the migration and invasion process; T cell factor (TCF) reporter plasmid for the evaluation of transciption factor (TCF) transcriptional activity; polymerase chain reaction (PCR) of target genes and confocal fluorescence microscopy for β-Catenin and E-Cadherin protein fluorescence levels; and subcellular localization. Our results showed a potential modulatory effect of the Wnt pathway on CRC cells, and we observed a reduction in the transcriptional activity of β-catenin. All the results were prominent in SW480 cells, where the Wnt pathway deregulation has more relevance and implies a constitutive activation of the signaling pathway. These results establish a starting point for the discovery of a mechanism of action associated with these effects and corroborate the anticancer potential of polyphenols present in coffee, which could be explored as chemopreventive molecules or as adjunctive therapy in CRC.

Elevation of spermine remodels immunosuppressive microenvironment through driving the modification of PD-L1 in hepatocellular carcinoma

Background

Spermine is frequently elevated in tumor tissues and body fluids of cancer patients and is critical for cancer cell proliferation, migration and invasion. However, the immune functions of spermine in hepatocellular carcinoma progression remains unknown. In the present study, we aimed to elucidate immunosuppressive role of spermine in hepatocellular carcinoma and to explore the underlying mechanism.

Methods

Whole-blood spermine concentration was measured using HPLC. Human primary HCC tissues were collected to examine the expression of CaSR, p-Akt, β-catenin, STT3A, PD-L1, and CD8. Mouse model of tumorigenesis and lung metastasis were established to evaluate the effects of spermine on hepatocellular carcinoma. Western blotting, immunofluorescence, real time PCR, digital Ca2+ imaging, and chromatin immunoprecipitation assay were used to investigate the underlying mechanisms by which spermine regulates PD-L1 expression and glycosylation in hepatocellular carcinoma cells.

Results

Blood spermine concentration in the HCC patient group was significantly higher than that in the normal population group. Spermine could facilitate tumor progression through inducing PD-L1 expression and decreasing the CD8+ T cell infiltration in HCC. Mechanistically, spermine activates calcium-sensing receptor (CaSR) to trigger Ca2+ entry and thereby promote Akt-dependent β-catenin stabilization and nuclear translocation. Nuclear β-catenin induced by spermine then activates transcriptional expression of PD-L1 and N-glycosyltransferase STT3A, while STT3A in turn increases the stability of PD-L1 through inducing PD-L1 protein N-glycosylation in HCC cells.

Conclusions

This study reveals the crucial function of spermine in establishing immune privilege by increasing the expression and N-glycosylation of PD-L1, providing a potential strategy for the treatment of hepatocellular carcinoma.

Icariin attenuates the tumor growth by targeting miR-1-3p/TNKS2/Wnt/β-catenin signaling axis in ovarian cancer

Purpose

Despite various therapy advances, ovarian cancer remains an incurable disease for which survival rates have only modestly improved. Natural products are important sources of anti-cancer lead compounds. Icariin exhibited broad anti-cancer efficacy. However, the mechanism of icariin against ovarian cancer is poorly elucidated.

Methods

Cell viability was detected to evaluate the effect of icariin on SKOV-3 cells. The cell cycle and apoptosis were analyzed. The transcript of SKOV-3 cells was profiled by RNA-seq. GSEA and DEGs analyses were performed to interpret gene expression data. Western blot and TOP/FOP flash assay were applied to detect Wnt/β-catenin signaling. MiRDB database and dual-luciferase reporter assay was applied to study the regulation of miR-1-3p on TNKS2. Anti-tumor efficacy of icariin was evaluated by xenograft mouse model. Immunohistochemistry was performed with antibodies against Ki67.

Results

Icariin significantly suppressed the proliferation of SKOV-3 cells. Furthermore, icariin stalled cell cycle and induced apoptosis by blocking TNKS2/Wnt/β-catenin pathway through upregulating the level of miR-1-3p. Finally, icariin dramatically suppressed tumor growth in vivo.

Conclusions

In this study, we demonstrated for the first time that icariin significantly attenuated the growth of ovarian tumor in xenograft mouse model. Furthermore, we systematically revealed that icariin attenuates the tumor progression by suppressing TNKS2/Wnt/β-catenin signaling via upregulating the level of miR-1-3p in ovarian cancer with transcriptome analysis.

Current Opportunities for Targeting Dysregulated Neurodevelopmental Signaling Pathways in Glioblastoma

Glioblastoma (GBM) is the most common and highly lethal type of brain tumor, with poor survival despite advances in understanding its complexity. After current standard therapeutic treatment, including tumor resection, radiotherapy and concomitant chemotherapy with temozolomide, the median overall survival of patients with this type of tumor is less than 15 months. Thus, there is an urgent need for new insights into GBM molecular characteristics and progress in targeted therapy in order to improve clinical outcomes. The literature data revealed that a number of different signaling pathways are dysregulated in GBM. In this review, we intended to summarize and discuss current literature data and therapeutic modalities focused on targeting dysregulated signaling pathways in GBM. A better understanding of opportunities for targeting signaling pathways that influences malignant behavior of GBM cells might open the way for the development of novel GBM-targeted therapies.

S-Adenosylmethionine Inhibits Colorectal Cancer Cell Migration through Mirna-Mediated Targeting of Notch Signaling Pathway

Metastasis is a leading cause of mortality and poor prognosis in colorectal cancer (CRC). Thus, the identification of new compounds targeting cell migration represents a major clinical challenge. Recent findings evidenced a central role for dysregulated Notch in CRC and a correlation between Notch overexpression and tumor metastasis. MicroRNAs (miRNAs) have been reported to cross-talk with Notch for its regulation. Therefore, restoring underexpressed miRNAs targeting Notch could represent an encouraging therapeutic approach against CRC. In this context, S-adenosyl-L-methionine (AdoMet), the universal biological methyl donor, being able to modulate the expression of oncogenic miRNAs could act as a potential antimetastatic agent. Here, we showed that AdoMet upregulated the onco-suppressor miRNAs-34a/-34c/-449a and inhibited HCT-116 and Caco-2 CRC cell migration. This effect was associated with reduced expression of migration-/EMT-related protein markers. We also found that, in colorectal and triple-negative breast cancer cells, AdoMet inhibited the expression of Notch gene, which, by luciferase assay, resulted the direct target of miRNAs-34a/-34c/-449a. Gain- and loss-of-function experiments with miRNAs mimics and inhibitors demonstrated that AdoMet exerted its inhibitory effects by upregulating miRNAs-34a/-34c/-449a. Overall, these data highlighted AdoMet as a novel Notch inhibitor and suggested that the antimetastatic effects of AdoMet involve the miRNA-mediated targeting of Notch signaling pathway.

Computational studies with flavonoids and terpenoids as BRPF1 inhibitors: in silico biological activity prediction, molecular docking, molecular dynamics simulations, MM/PBSA calculations

The BRPF1 protein is encoded by the BRPF1 gene. In addition, the BRPF1 gene is known to be upregulated in leukaemia. Recent studies have shown that it is also overexpressed in hepatocellular carcinoma (HCC) as well. Therefore, BRPF1 is a significant target for anti-cancer drug development studies, especially on HCC. 40 terpenoids and flavonoids were chosen because of their anticancer properties given in the literature. In this study, the biological activity of molecules was also investigated with in silico structure-activity relationship analysis. In addition, interactions between a series of terpenoids and flavonoids and the BRPF1 protein were investigated by molecular docking and molecular dynamics simulations. The energy change caused by the interactions of BRPF1 with different compounds was also evaluated by MM/PBSA calculations. It has been revealed that compound 5 (-9.2 kcal/mol), a kind of secoclerodane type diterpenoid, has a higher affinity both compared to other flavonoids and terpenoids, and 9F9 (-7.9 kcal/mol), a selective BRPF1 inhibitor. The study presented in this article demonstrates that compound 5, as a natural product, could form a chemical scaffold for the development of selective BRPF1 bromodomain inhibitors.

In silico Prediction on the PI3K/AKT/mTOR Pathway of the Antiproliferative Effect of O. joconostle in Breast Cancer Models

The search for new cancer treatments from traditional medicine involves developing studies to understand at the molecular level different cell signaling pathways involved in cancer development. In this work, we present a model of the PI3K/Akt/mTOR pathway, which plays a key role in cell cycle regulation and is related to cell survival, proliferation, and growth in cancer, as well as resistance to antitumor therapies, so finding drugs that act on this pathway is ideal to propose a new adjuvant treatment. The aim of this work was to model, simulate and predict in silico using the Big Data-Cellulat platform the possible targets in the PI3K/Akt/mTOR pathway on which the Opuntia joconostle extract acts, as well as to indicate the concentration range to be used to find the mean lethal dose in in vitro experiments on breast cancer cells. The in silico results show that, in a cancer cell, the activation of JAK and STAT, as well as PI3K and Akt is related to the effect of cell proliferation, angiogenesis, and inhibition of apoptosis, and that the extract of O. joconostle has an antiproliferative effect on breast cancer cells by inhibiting cell proliferation, regulating the cell cycle and inhibiting apoptosis through this signaling pathway . In vitro it was demonstrated that the extract shows an antiproliferative effect, causing the arrest of cells in the G2/M phase of the cell cycle. Therefore, it is concluded that the use of in silico tools is a valuable method to perform virtual experiments and discover new treatments. The use of this type of model supports in vitro experimentation, reducing the costs and number of experiments in the real laboratory.

Transformation of nomifensine using ionizing radiation and exploration of its anticancer effects in MCF‑7 cells

Breast cancer is one of the most challenging diseases to treat in humans worldwide. There are several alternatives in treating this life-threatening disease; however, chemoresistance is probably the biggest obstacle to the treatment of breast cancer. It may be essential to develop a therapeutic candidate material with less reversible effects and high treatment efficiency to solve this problem. The present study applied an ionizing radiation approach employing nomifensine (NF) to transform its chemical characteristics and investigated its potential to kill human breast cancer cells (MCF-7). Irradiated (IR-) NF was analyzed using high-performance liquid chromatography. The findings showed that NF inhibited the proliferation of breast cancer cells and increased the rate of apoptosis. In addition, IR-NF induced the accumulation of cytosolic reactive oxygen species and enhanced mitochondrial aggregation. Additionally, mitogen-activated protein kinases (extracellular signal-regulated kinase 1/2, p38 and c-Jun NH 2-terminal kinase) were involved in damage signaling induced by IR-NF and IR-NF suppressed β-catenin nuclear translocation. It is suggested that irradiation can be an effective method to maximize the efficacy of existing drugs and that IR-NF has the potential to be a drug candidate for treating patients with breast cancer.

Anticancer Effects and Molecular Action of 7-α-Hydroxyfrullanolide in G2/M-Phase Arrest and Apoptosis in Triple Negative Breast Cancer Cells

Triple negative breast cancer (TNBC) is a breast cancer subtype characterized by the absence of estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 expression. TNBC cells respond poorly to targeted chemotherapies currently in use and the mortality rate of TNBC remains high. Therefore, it is necessary to identify new chemotherapeutic agents for TNBC. In this study, the anti-cancer effects of 7-α-hydroxyfrullanolide (7HF), derived from Grangea maderaspatana, on MCF-7, MDA-MB-231 and MDA-MB-468 breast cancer cells were assessed using MTT assay. The mode of action of 7HF in TNBC cells treated with 6, 12 and 24 µM of 7HF was determined by flow cytometry and propidium iodide (PI) staining for cell cycle analysis and annexin V/fluorescein isothiocyanate + PI staining for detecting apoptosis. The molecular mechanism of action of 7HF in TNBC cells was investigated by evaluating protein expression using proteomic techniques and western blotting. Subsequently, 7HF exhibited the strongest anti-TNBC activity toward MDA-MB-468 cells and a concomitantly weak toxicity toward normal breast cells. The molecular mechanism of action of low-dose 7HF in TNBC cells primarily involved G2/M-phase arrest through upregulation of the expression of Bub3, cyclin B1, phosphorylated Cdk1 (Tyr 15) and p53-independent p21. Contrastingly, the upregulation of PP2A-A subunit expression may have modulated the suppression of various cell survival proteins such as p-Akt (Ser 473), FoxO3a and β-catenin. The concurrent apoptotic effect of 7HF on the treated cells was mediated via both intrinsic and extrinsic modes through the upregulation of Bax and active cleaved caspase-7-9 expression and downregulation of Bcl-2 and full-length caspase-7-9 expression. Notably, the proteomic approach revealed the upregulation of the expression of pivotal protein clusters associated with G1/S-phase arrest, G2/M-phase transition and apoptosis. Thus, 7HF exhibits promising anti-TNBC activity and at a low dose, it modulates signal transduction associated with G2/M-phase arrest and apoptosis.

The Wnt/β-catenin pathway in breast cancer therapy: a pre-clinical perspective of its targeting for clinical translation

INTRODUCTION

Despite various treatments available, there is still a high mortality rate in breast cancer patients. Thus, there exists an unmet need for new therapeutic interventions. Studies show that the Wnt/β-catenin signaling pathway is involved in breast cancer metastasis because of its transcriptional control on epithelial to mesenchymal transition.

AREAS COVERED

This comprehensive review explores the Wnt signaling pathway as a potential target for treating breast cancer and other breast cancer subtypes. We discuss the Wnt signaling pathway, its role in breast cancer metastasis, and its effect on breast cancer stem cells. Further, endogenous agents that cause Wnt pathway inactivation are outlined. Finally, various natural and chemical compounds modulating the Wnt pathway used in pre-clinical or clinical trials for breast cancer treatment are discussed.

EXPERT OPINION

In vitro and in vivo studies indicate an immense potential of agents targeting the Wnt signaling pathway to prevent and manage breast cancer. Still, more clinical studies are required to support their use in humans. Apart from the agents already in clinical trials, several drug combinations discussed may be translated into clinical practice in a few years.

Natural products targeting cancer cell dependency

Precision cancer medicine is a tailored treatment approach for individual cancer patients with different genomic characteristics. Mutated or hyperactive oncogenes have served as main drug targets in current precision cancer medicine, while defective or inactivated tumor suppressors in general have not been considered as druggable targets. Synthetic lethality is one of very few approaches that enable to target defective tumor suppressors with pharmacological agents. Synthetic lethality exploits cancer cell dependency on a protein or pathway, which arises when the function of a tumor suppressor is defective. This approach has been proven to be effective in clinical settings since the successful clinical introduction of BRCA-PARP synthetic lethality for the treatment of breast and ovarian cancer with defective BRCA. Subsequently, large-scale screenings with RNAi, CRISPR/Cas9-sgRNAs, and chemical libraries have been applied to identify synthetic lethal partners of tumor suppressors. Natural products are an important source for the discovery of pharmacologically active small molecules. However, little effort has been made in the discovery of synthetic lethal small molecules from natural products. This review introduces recent advances in the discovery of natural products targeting cancer cell dependency and discusses potentials of natural products in the precision cancer medicine.

The multidimensional role of the Wnt/β-catenin signaling pathway in human malignancies

Several signaling pathways have been identified as important for developmental processes. One of such important cascades is the Wnt/β-catenin signaling pathway, which can regulate various physiological processes such as embryonic development, tissue homeostasis, and tissue regeneration; while its dysregulation is implicated in several pathological conditions especially cancers. Interestingly, deregulation of the Wnt/β-catenin pathway has been reported to be closely associated with initiation, progression, metastasis, maintenance of cancer stem cells, and drug resistance in human malignancies. Moreover, several genetic and experimental models support the inhibition of the Wnt/β-catenin pathway to answer the key issues related to cancer development. The present review focuses on different regulators of Wnt pathway and how distinct mutations, deletion, and amplification in these regulators could possibly play an essential role in the development of several cancers such as colorectal, melanoma, breast, lung, and leukemia. Additionally, we also provide insights on diverse classes of inhibitors of the Wnt/β-catenin pathway, which are currently in preclinical and clinical trial against different cancers.

Polyphenol Containing Sorghum Brans Exhibit an Anti-Cancer Effect in Apc Min/+ Mice Treated with Dextran Sodium Sulfate

Colon cancer (CC) is considered a high-risk cancer in developed countries. Its etiology is correlated with a high consumption of red meat and low consumption of plant-based foods, including whole grains. Sorghum bran is rich in polyphenols. This study aimed to determine whether different high-phenolic sorghum brans suppress tumor formation in a genetic CC rodent model and elucidate mechanisms. Tissue culture experiments used colorectal cancer cell lines SW480, HCT-116 and Caco-2 and measured protein expression, and protein activity. The animal model used in this study was APC Min+/mouse model combined with dextram sodium sulfate. High phenolic sorghum bran extract treatment resulted in the inhibition of proliferation and induced apoptosis in CC cell lines. Treatment with high phenolic sorghum bran extracts repressed TNF-α-stimulated NF-κB transactivation and IGF-1-stimulated PI3K/AKT pathway via the downregulation of β-catenin transactivation. Furthermore, high-phenolic sorghum bran extracts activated AMPK and autophagy. Feeding with high-phenolic sorghum bran for 6 weeks significantly suppressed tumor formation in an APC Min/+ dextran sodium sulfate promoted CC mouse model. Our data demonstrates the potential application of high-phenolic sorghum bran as a functional food for the prevention of CC.

Natural Products as a Promising Therapeutic Strategy to Target Cancer Stem Cells

Cancer is still a deadly disease, and its treatment desperately needs to be managed in a very sophisticated way through fast-developing novel strategies. Most of the cancer cases eventually develop into recurrencies, for which cancer stem cells (CSCs) are thought to be responsible. They are considered as a subpopulation of all cancer cells of tumor tissue with aberrant regulation of self-renewal, unbalanced proliferation, and cell death properties. Moreover, CSCs show a serious degree of resistance to chemotherapy or radiotherapy and immune surveillance as well. Therefore, new classes of drugs are rushing into the market each year, which makes the cost of therapy increase dramatically. Natural products are also becoming a new research area as a diverse chemical library to suppress CSCs. Some of the products even show promise in this regard. So, the near future could witness the introduction of natural products as a source of new chemotherapy modalities, which may result in the development of novel anticancer drugs. They could also be a reasonably-priced alternative to highly expensive current treatments. Nowadays, considering the effects of natural compounds on targeting surface markers, signaling pathways, apoptosis, and escape from immunosurveillance have been a highly intriguing area in preclinical and clinical research. In this review, we present scientific advances regarding their potential use in the inhibition of CSCs and the mechanisms by which they kill the CSCs.

The role of miRNAs in MDMX-p53 interplay

MicroRNAs (miRNAs) are endogenous noncoding RNAs of 19-24 nucleotides in length and are tightly related to tumorigenesis and progression. Recent studies have demonstrated that the tumor suppressor p53 and its negative controller MDMX are regulated by miRNAs in different ways. Some miRNAs directly target p53 and regulate its expression and function, whereas some miRNAs target MDMX and regulate p53's activity indirectly. The overexpression of several miRNAs can restore the activity of p53 by negatively regulating MDMX in cancer cells. Therefore, a better understanding of the miRNAs-MDMX-p53 network will put forward potential research directions for developing anticancer therapeutics. In the present review, we mainly focus on the regulatory effects of miRNAs on the MDMX-p53 interplay as well as the role of the miRNAs-MDMX-p53 network in human cancer.

Small-Molecule Inhibitors Targeting the Canonical WNT Signaling Pathway for the Treatment of Cancer

Canonical WNT signaling is an important developmental pathway that has attracted increased attention for anticancer drug discovery. From the production and secretion of WNT ligands, their binding to membrane receptors, and the β-catenin destruction complex to the expansive β-catenin transcriptional complex, multiple components have been investigated as drug targets to modulate WNT signaling. Significant progress in developing WNT inhibitors such as porcupine inhibitors, tankyrase inhibitors, β-catenin/coactivators, protein-protein interaction inhibitors, casein kinase modulators, DVL inhibitors, and dCTPP1 inhibitors has been made, with several candidates (e.g., LGK-974, PRI-724, and ETC-159) in human clinical trials. Herein we summarize recent progress in the drug discovery and development of small-molecule inhibitors targeting the canonical WNT pathway, focusing on their specific target proteins, in vitro and in vivo activities, physicochemical properties, and therapeutic potential. The relevant opportunities and challenges toward maintaining the balance between efficacy and toxicity in effectively targeting this pathway are also highlighted.

The Role of Oxidative Stress and Natural Antioxidants in Ovarian Aging

The ovarian system comprises vital organs in females and is of great significance for the maintenance of reproductive potential and endocrine stability. Although complex pathogenesis undoubtedly contributes to ovarian aging, increasing attention is being paid to the extensive influence of oxidative stress. However, the role of oxidative stress in ovarian aging is yet to be fully elucidated. Exploring oxidative stress-related processes might be a promising strategy against ovarian aging. In this review, compelling evidence is shown that oxidative stress plays a role in the etiology of ovarian aging and promotes the development of other ovarian aging-related etiologies, including telomere shortening, mitochondrial dysfunction, apoptosis, and inflammation. In addition, some natural antioxidants such as quercetin, resveratrol, and curcumin have a protective role in the ovaries through multiple mechanisms. These findings raise the prospect of oxidative stress modulator-natural antioxidants as therapeutic interventions for delaying ovarian aging.

Dehydroxyhispolon Methyl Ether, A Hispolon Derivative, Inhibits WNT/β-Catenin Signaling to Elicit Human Colorectal Carcinoma Cell Apoptosis

Colorectal cancer (CRC) is the fourth leading cause of cancer mortality worldwide. Aberrant activation of WNT/β-catenin signaling present in the vast majority of CRC cases is indispensable for CRC initiation and progression, and thus is a promising target for CRC therapeutics. Hispolon is a fungal-derived polyphenol with a pronounced anticancer effect. Several hispolon derivatives, including dehydroxyhispolon methyl ether (DHME), have been chemically synthesized for developing lead molecules with stronger anticancer activity. Herein, a DHME-elicited anti-CRC effect with the underlying mechanism is reported for the first time. Specifically, DHME was found to be more cytotoxic than hispolon against a panel of human CRC cell lines, while exerting limited toxicity to normal human colon cell line CCD 841 CoN. Additionally, the cytotoxic effect of DHME appeared to rely on inducing apoptosis. This notion was evidenced by DHME-elicited upregulation of poly (ADP-ribose) polymerase (PARP) cleavage and a cell population positively stained by annexin V, alongside the downregulation of antiapoptotic B-cell lymphoma 2 (BCL-2), whereas the blockade of apoptosis by the pan-caspase inhibitor z-VAD-fmk attenuated DHME-induced cytotoxicity. Further mechanistic inquiry revealed the inhibitory action of DHME on β-catenin-mediated, T-cell factor (TCF)-dependent transcription activity, suggesting that DHME thwarted the aberrantly active WNT/β-catenin signaling in CRC cells. Notably, ectopic expression of a dominant–active β-catenin mutant (∆N90-β-catenin) abolished DHME-induced apoptosis while also restoring BCL-2 expression. Collectively, we identified DHME as a selective proapoptotic agent against CRC cells, exerting more potent cytotoxicity than hispolon, and provoking CRC cell apoptosis via suppression of the WNT/β-catenin signaling axis.