Phloretin suppresses metastasis by targeting protease and inhibits cancer stemness and angiogenesis in human cervical cancer cells

Elucidating the molecular mechanisms of pterostilbene against cervical cancer through an integrated bioinformatics and network pharmacology approach

Pterostilbene (PTE), a natural phenolic compound, has exhibited promising anticancer properties in the preclinical treatment of cervical cancer (CC). This study aims to comprehensively investigate the potential targets and mechanisms underlying PTE's anticancer effects in CC, thereby providing a theoretical foundation for its future clinical application and development. To accomplish this, we employed a range of methodologies, including network pharmacology, bioinformatics, and computer simulation, with specific techniques such as WGCNA, PPI network construction, ROC curve analysis, KM survival analysis, GO functional enrichment, KEGG pathway enrichment, molecular docking, MDS, and single-gene GSEA. Utilizing eight drug target prediction databases, we have identified a total of 532 potential targets for PTE. By combining CC-related genes from the GeneCards disease database with significant genes derived from WGCNA analysis of the GSE63514 dataset, we obtained 7915 unique CC-related genes. By analyzing the intersection of the 7915 CC-related genes and the 2810 genes that impact overall survival time in CC, we identified 690 genes as crucial for CC. Through the use of a Venn diagram, we discovered 36 overlapping targets shared by PTE and CC. We have constructed a PPI network and identified 9 core candidate targets. ROC and KM curve analyses subsequently revealed IL1B, EGFR, IL1A, JUN, MYC, MMP1, MMP3, and ANXA5 as the key targets modulated by PTE in CC. GO and KEGG pathway enrichment analyses indicated significant enrichment of these key targets, primarily in the MAPK and IL-17 signaling pathways. Molecular docking analysis verified the effective binding of PTE to all nine key targets. MDS results showed that the protein-ligand complex between MMP1 and PTE was the most stable among the nine targets. Additionally, GSEA enrichment analysis suggested a potential link between elevated MMP1 expression and the activation of the IL-17 signaling pathway. In conclusion, our study has identified key targets and uncovered the molecular mechanism behind PTE's anticancer activity in CC, establishing a firm theoretical basis for further exploration of PTE's pharmacological effects in CC therapy.

Strategy for the Enzymatic Acylation of the Apple Flavonoid Phloretin Based on Prior α-Glucosylation

The acylation of flavonoids serves as a means to alter their physicochemical properties, enhance their stability, and improve their bioactivity. Compared with natural flavonoid glycosides, the acylation of nonglycosylated flavonoids presents greater challenges since they contain fewer reactive sites. In this work, we propose an efficient strategy to solve this problem based on a first α-glucosylation step catalyzed by a sucrose phosphorylase, followed by acylation using a lipase. The method was applied to phloretin, a bioactive dihydrochalcone mainly present in apples. Phloretin underwent initial glucosylation at the 4'-OH position, followed by subsequent (and quantitative) acylation with C8, C12, and C16 acyl chains employing an immobilized lipase from Thermomyces lanuginosus. Electrospray ionization-mass spectrometry (ESI-MS) and two-dimensional nuclear magnetic resonance spectroscopy (2D-NMR) confirmed that the acylation took place at 6-OH of glucose. The water solubility of C8 acyl glucoside closely resembled that of aglycone, but for C12 and C16 derivatives, it was approximately 3 times lower. Compared with phloretin, the radical scavenging capacity of the new derivatives slightly decreased with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and was similar to 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+). Interestingly, C12 acyl-α-glucoside displayed an enhanced (3-fold) transdermal absorption (using pig skin biopsies) compared to phloretin and its α-glucoside.

Phytochemicals Showing Antiangiogenic Effect in Pre-clinical Models and their Potential as an Alternative to Existing Therapeutics

Angiogenesis, the formation of new blood vessels from a pre-existing vascular network, is an important hallmark of several pathological conditions, such as tumor growth and metastasis, proliferative retinopathies, including proliferative diabetic retinopathy and retinopathy of prematurity, age-related macular degeneration, rheumatoid arthritis, psoriasis, and endometriosis. Putting a halt to pathology-driven angiogenesis is considered an important therapeutic strategy to slow down or reduce the severity of pathological disorders. Considering the attrition rate of synthetic antiangiogenic compounds from the lab to reaching the market due to severe side effects, several compounds of natural origin are being explored for their antiangiogenic properties. Employing pre-clinical models for the evaluation of novel antiangiogenic compounds is a promising strategy for rapid screening of antiangiogenic compounds. These studies use a spectrum of angiogenic model systems that include HUVEC two-dimensional culture, nude mice, chick chorioallantoic membrane, transgenic zebrafish, and dorsal aorta from rats and chicks, depending upon available resources. The present article emphasizes the antiangiogenic activity of the phytochemicals shown to exhibit antiangiogenic behavior in these well-defined existing angiogenic models and highlights key molecular targets. Different models help to get a quick understanding of the efficacy and therapeutics mechanism of emerging lead molecules. The inherent variability in assays and corresponding different phytochemicals tested in each study prevent their immediate utilization in clinical studies. This review will discuss phytochemicals discovered using suitable preclinical antiangiogenic models, along with a special mention of leads that have entered clinical evaluation.

The multifaceted roles of matrix metalloproteinases in lung cancer

Background

Though the matrix metalloproteinases (MMPs) are widely investigated in lung cancer (LC), however, almost no review systematically clarify their multi-faced roles in LC.

Methods

We investigated the expression of MMPs and their effects on survival of patients with LC, the resistance mechanisms of MMPs in anti-tumor therapy, the regulatory networks of MMPs involved, the function of MMPs inducing CSCLs, MMPs-related tumor immunity, and effects of MMP polymorphisms on risk of LC.

Results

High expression of MMPs was mainly related to poor survival, high clinical stages and cancer metastasis. Role of MMPs in LC are multi-faced. MMPs are involved in drug resistance, induced CSCLs, participated in tumor immunity. Besides, MMPs polymorphisms may increase risk of LC.

Conclusions

MMPs might be promising targets to restore the anti-tumor immune response and enhance the killing function of nature immune cells in LC.

Detoxification of the Lipid Peroxidation Aldehyde, 4-Hydroxynonenal, by Apple Phloretin In Vitro and in Mice

4-Hydroxy-2-nonenal (4-HNE) is a secondary cytotoxic product generated from lipid peroxidation of polyunsaturated fatty acids (PUFAs). The accumulation of 4-HNE can covalently modify biomolecules, such as DNA and proteins, leading to various pathological conditions. Apple phloretin has been shown to be able to trap 4-HNE in vitro, but the trapping mechanisms of 4-HNE by phloretin are not fully understood. Moreover, whether the in vitro trapping efficacy of phloretin toward 4-HNE could be transferred into in vivo environments has never been investigated. In the present study, we observed the formation of 4-HNE conjugates of phloretin increased as phloretin decreased during the in vitro incubation. We then purified and characterized three mono-4-HNE-conjugates of phloretin using NMR and LC-MS/MS techniques. We thereafter demonstrated that apple phloretin could scavenge in vivo 4-HNE via the formation of at least three mono-4-HNE-conjugates of phloretin in a dose-dependent manner in mice after oral administration of three doses of phloretin (25, 100, and 400 mg/kg). The findings from this study pave the way to understanding how dihydrochalcones could act as effective scavengers of 4-HNE by working as sacrificial nucleophiles in vivo, thereby preventing or reducing the risk of 4-HNE-associated chronic diseases.

Phloretin, as a Potent Anticancer Compound: From Chemistry to Cellular Interactions

Phloretin is a natural dihydrochalcone found in many fruits and vegetables, especially in apple tree leaves and the Manchurian apricots, exhibiting several therapeutic properties, such as antioxidant, antidiabetic, anti-inflammatory, and antitumor activities. In this review article, the diverse aspects of the anticancer potential of phloretin are addressed, presenting its antiproliferative, proapoptotic, antimetastatic, and antiangiogenic activities in many different preclinical cancer models. The fact that phloretin is a planar lipophilic polyphenol and, thus, a membrane-disrupting Pan-Assay Interference compound (PAIN) compromises the validity of the cell-based anticancer activities. Phloretin significantly reduces membrane dipole potential and, therefore, is expected to be able to activate a number of cellular signaling pathways in a non-specific way. In this way, the effects of this minor flavonoid on Bax and Bcl-2 proteins, caspases and MMPs, cytokines, and inflammatory enzymes are all analyzed in the current review. Moreover, besides the anticancer activities exerted by phloretin alone, its co-effects with conventional anticancer drugs are also under discussion. Therefore, this review presents a thorough overview of the preclinical anticancer potential of phloretin, allowing one to take the next steps in the development of novel drug candidates and move on to clinical trials.

Antitumor activity of pachymic acid in cervical cancer through inducing endoplasmic reticulum stress, mitochondrial dysfunction, and activating the AMPK pathway

Pachymic acid has various pharmacological effects, including anti-inflammatory, antioxidant, immunomodulatory, and antitumor. However, the role of pachymic acid in cervical cancer remains unclear. So, we investigated the effects of pachymic acid in cervical cancer and elucidated the underlying mechanisms. We treated HeLa cells and normal cervical epithelial cells (HUCECs) with pachymic acid (0, 10, 20, 40, 80, or 160 μM) for 72 h, and found the cell activity was decreased in cells treated with 160 μM pachymic acid for 48 h or 80 μM pachymic acid for 72 h, while HUCECs viability without effect. Next, we observed that endoplasmic reticulum (ER) related gene expression, mitochondrial membrane potential (MMP) changes, ATP depletion, reactive oxygen species (ROS) generation and apoptosis were increased. Moreover, we observed that cytochrome C (Cytc) expression was increased and apoptosis-inducing factor (AIF) was decreased in the cytoplasm of pachymic acid-treated HeLa cells. Tauroursodeoxycholic acid (TUDCA) of ER stress inhibitor reversed the effects of pachymic acid on HeLa cells. Phosphorylation of AMPK and acetyl-CoA carboxylase (ACC) of the AMPK pathway key protein was upregulated in pachymic acid-induced HeLa cells. Finally, we subcutaneously implanted HeLa cells into female nude mice and treated them with pachymic acid (50 mg/kg) for 3 weeks (5 days/week), and observed in pachymic acid induced xenograft mice, tumor growth was suppressed, cell apoptosis, ER-related gene expression, and ROS levels in tumor tissues were increased. Therefore, these findings demonstrated that pachymic acid plays an anti-tumor activity in cervical cancer through inducing ER stress, mitochondrial dysfunction, and activating the AMPK pathway.

Role of phloretin as a sensitizer to TRAIL‑induced apoptosis in colon cancer

Phloretin is one of the apple polyphenols with anticancer activities. Since tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) serves important roles in inducing apoptosis, the present study examined the effect of phloretin on TRAIL-induced apoptosis in colon cancer cells. Treatment with both phloretin and TRAIL markedly suppressed the survival of cancer cells from several colon cancer cell lines compared with that of cells treated with either TRAIL or phloretin. Additionally, decreased numbers of colonies were observed following addition of phloretin and TRAIL. Furthermore, TRAIL- and phloretin-treated HT-29-Luc cells exhibited decreased luciferase activity. Increased apoptosis was observed in phloretin- and TRAIL-treated HT-29-Luc colon cancer cells, accompanying elevated levels of cleaved poly(ADP-ribose) polymerase, and caspase-3, −8 and −9. The expression levels of MCL1 apoptosis regulator BCL2 family member (Mcl-1) were decreased following addition of phloretin in colon cancer cells. In addition, overexpression of Mcl-1 in phloretin- and TRAIL-treated HT-29-Luc cells resulted in increased cell survival. Treatment of HT-29-Luc cells with a combination of cycloheximide (CHX) and phloretin led to a more prominent decrease in Mcl-1 expression compared with that in cells treated with CHX alone, while Mcl-1 expression was recovered by treatment with MG132. Binding of ubiquitin with Mcl-1 was verified using immunoprecipitation. Intraperitoneal injection of both TRAIL and phloretin into tumor xenografts was associated with a decreased tumor volume compared with that following injection with either TRAIL or phloretin. Overall, the present results suggest a synergistic effect of phloretin on TRAIL-induced apoptosis in colon cancer cells.

Phloretin ameliorates diabetic nephropathy by inhibiting nephrin and podocin reduction through a non-hypoglycemic effect

Phloretin is a dihydrochalcone flavonoid from natural plants, which has protective activities against oxidative stress and inflammation. To date, its effect on diabetic nephropathy (DN) has not been investigated. In this study, we examined the potential role of phloretin in diabetes-induced renal damage and associated mechanisms in a type 2 diabetes mellitus (T2DM) model induced by streptozotocin (STZ) and high-fat diet (HFD) in Apolipoprotein E knockout (ApoE^-/-) mice. We found that daily treatment with a low dose (20 mg kg^-1) of phloretin, as a dietary supplement, significantly alleviated polyuria, proteinuria, and glomerular histopathological changes in the T2DM mice, indicating a protective effect of phloretin on diabetic renal dysfunction. In the phloretin-treated T2DM mice, major metabolic parameters, including blood glucose levels, were not altered significantly, suggesting that the observed beneficial effects of phloretin may be due to a mechanism independent of blood glucose control. Further experiments revealed that phloretin had a protective effect on glomerular podocytes as indicated by ameliorated glomerular basement membrane (GBM) thickening and podocyte foot process effacement. Moreover, phloretin treatment restored levels of nephrin and podocin, two podocyte slit diaphragm proteins that were decreased in T2DM mice. Our results indicate that low-dose phloretin treatment has a protective effect on podocytes in DN via a non-hypoglycemic mechanism in preserving nephrin and podocin expression levels. These data suggest that phloretin may be exploited as a novel therapeutic agent for DN.

Cinnamaldehyde decreases the invasion and u-PA expression of osteosarcoma by down-regulating the FAK signalling pathway

Cancer metastasis is the major cause of the high mortality risk of patients with osteosarcoma. Cinnamaldehyde has been shown to exhibit multiple tumour-suppressing activities, but its role in human osteosarcoma is not yet completely defined. In this study, the antimetastatic effect of cinnamaldehyde on highly metastatic human osteosarcoma cells was observed in vitro and in vivo using Saos-2 and 143B cells. Cinnamaldehyde reduced the activity and protein level of urokinase-type plasminogen activator (u-PA) and suppressed the invasion ability of osteosarcoma cells by inhibiting the phosphorylation of focal adhesion kinase. In addition, cinnamaldehyde reduced cell movement, cell-matrix adhesion, and the expression of the mesenchymal markers of epithelial-to-mesenchymal transition, namely, fibronectin and N-cadherin. Importantly, the oral administration of cinnamaldehyde remarkably suppressed the pulmonary metastasis of osteosarcoma in mice. Results indicated that cinnamaldehyde has therapeutic potential for inhibiting osteosarcoma metastasis.

Reduction of invasion and cell stemness and induction of apoptotic cell death by Cinnamomum cassia extracts on human osteosarcoma cells

Cinnamomum cassia possesses antioxidative activity and induces the apoptotic properties of various cancer types. However, its effect on osteosarcoma invasion and cancer stemness remains ambiguous. Here, we examined the molecular evidence of the anti-invasive effects of ethanoic C. cassia extracts (CCE). Invasion and migration were obviously suppressed after the expression of urokinase-type plasminogen activator and matrix metalloprotein 2 in human osteosarcoma 143B cells were downregulated. CCE reversed epithelial-to-mesenchymal transition (EMT) induced by transforming growth factor β1 and downregulated mesenchymal markers, such as snail-1 and RhoA. CCE suppressed self-renewal property and the expression of stemness genes (aldehyde dehydrogenase, Nanog, and CD44) in the 143B cells. CCE suppressed cell viability, reduced the colony formation of osteosarcoma cancer cells, and induced apoptotic cell death in the 143B cells, as indicated by caspase-9 activation. The xenograft tumor model of immunodeficient BALB/c nude mice showed that CCE administered in vivo through oral gavage inhibited the growth of implanted 143B cells. These findings indicated that CCE inhibited the invasion, migration, and cancer stemness of the 143B cells. CCE reduced proliferation of 143B cell possibly because of the activation of caspase-9 and the consequent apoptosis, suggesting that CCE is a potential anticancer supplement for osteosarcoma.

"An apple a day keeps the doctor away": The potentials of apple bioactive constituents for chronic disease prevention

Apples are rich sources of selected micronutrients (e.g., iron, zinc, vitamins C and E) and polyphenols (e.g., procyanidins, phloridzin, 5′‐caffeoylquinic acid) that can help in mitigating micronutrient deficiencies (MNDs) and chronic diseases. This review provides an up‐to‐date overview of the significant bioactive compounds in apples together with their reported pharmacological actions against chronic diseases such as diabetes, cancer, and cardiovascular diseases. For consumers to fully gain these health benefits, it is important to ensure an all‐year‐round supply of highly nutritious and good‐quality apples. Therefore, after harvest, the physicochemical and nutritional quality attributes of apples are maintained by applying various postharvest treatments and hurdle techniques. The impact of these postharvest practices on the safety of apples during storage is also highlighted. This review emphasizes that advancements in postharvest management strategies that extend the storage life of apples should be optimized to better preserve the bioactive components crucial to daily dietary needs and this can help improve the overall health of consumers.

Dihydrochalcones as antitumor agents

Dihydrochalcones are a class of secondary metabolites, possessing several biological properties such as antitumor, antioxidant, antibacterial, antidiabetic, estrogenic, anti-inflammatory, antithrombotic, antiviral, neuroprotective and immunomodulator properties; therefore, they are currently considered promising candidates in the drug discovery process. This review intend to debate their pharmacological actions with a particular attention to their antitumor activity against a panel of cancer cell-lines and to the description of the inhibition mechanisms of cell proliferation such as the regulation of angiogenesis, apoptosis, etc etc.

Natural Bioactives: Back to the Future in the Fight against Human Papillomavirus? A Narrative Review

Human papillomavirus (HPV) still represents an important threat to health worldwide. Better therapy in terms of further improvement of outcomes and attenuation of related side-effects is desirable. The pharmaceutical industry has always targeted natural substances-phytochemicals in particular-to identify lead compounds to be clinically validated and industrially produced as antiviral and anticancer drugs. In the field of HPV, numerous naturally occurring bioactives and dietary phytochemicals have been investigated as potentially valuable in vitro and in vivo. Interference with several pathways and improvement of the efficacy of chemotherapeutic agents have been demonstrated. Notably, some clinical trials have been conducted. Despite being endowed with general safety, these natural substances are in urgent need of further assessment to foresee their clinical exploitation. This review summarizes the basic research efforts conducted so far in the study of anti-HPV properties of bio-actives with insights into their mechanisms of action and highlights the variety of their natural origin in order to provide comprehensive mapping throughout the different sources. The clinical studies available are reported, as well, to highlight the need of uniformity and consistency of studies in the future to select those natural compounds that may be suited to clinical application.

Demethoxycurcumin inhibits the cell migration and MMP-2 expression in human retinal pigment epithelial cells by targeting the STAT-3 pathway

Proliferative vitreoretinopathy (PVR) involves retinal pigment epithelium (RPE) cell proliferation and migration and leads to tractional retinal detachment. Demethoxycurcumin (DMC), a curcuminoid, has anti-inflammatory and anti-tumour properties. However, whether DMC affects the migration of RPE cells and the molecular mechanism of human PVR remains unclear. The aim of the current study was to investigate the effects of DMC on the inhibition of migration and proteinase expression of human ARPE-19 cells. Herein, we provided molecular evidence associated with PVR prevention through DMC by inhibiting ARPE-19 cell migration. We performed gelatin zymography, Western blot and RT-PCR and respectively found that DMC is sufficient to reduce matrix metalloproteinase-2 (MMP-2) activity, protein level and mRNA expression. DMC suppressed the nuclear levels of transcriptional factors specificity protein 1 and c-Fos, which are involved in the modulation of the transcriptional activation of the MMP-2 gene. DMC also inhibited STAT-3 phosphorylation in ARPE-19 cells. Selective STAT-3 induction by a STAT-3 activator, colivelin, reverted MMP activity and protein expression and cell migration, which were reduced in response to DMC. The results proved the inhibitory effect of DMC on RPE cell migration and MMP-2 expression by the down-regulation of the STAT-3 signalling pathway.

Indocyanine Green-Loaded PLGA Nanoparticles Conjugated with Hyaluronic Acid Improve Target Specificity in Cervical Cancer Tumors

PURPOSE

Indocyanine green (ICG) is a promising agent for intraoperative visualization of tumor tissues and sentinel lymph nodes in early-stage gynecological cancer. However, it has some limitations, including a short half-life and poor solubility in aqueous solutions. This study aimed to enhance the efficacy of near-infrared (NIR) fluorescence imaging by overcoming the shortcomings of ICG using a nano-drug delivery system and improve target specificity in cervical cancer.

MATERIALS AND METHODS

ICG and poly(lactic-co-glycolic acid) (PLGA) conjugated with polyethylenimine (PEI) were assembled to enhance stability. Hyaluronic acid (HA) was coated on PEI-PLGA-ICG nanoparticles to target CD44-positive cancer cells. The manufactured HA-ICG-PLGA nanoparticles (HINPs) were evaluated in vitro and in vivo on cervical cancer cells (SiHa; CD44+) and human dermal cells (ccd986sk; CD44-), respectively, using NIR imaging to compare intracellular uptake and to quantify the fluorescence intensities of cells and tumors.

RESULTS

HINPs were confirmed to have a mean size of 200 nm and a zeta-potential of 33 mV using dynamic light scattering. The stability of the HINPs was confirmed at pH 5.0-8.0. Cytotoxicity assays, intracellular uptake assays, and cervical cancer xenograft models revealed that, compared to free ICG, the HINPs had significantly higher internalization by cervical cancer cells than normal cells (p<0.001) and significantly higher accumulation in tumors (p<0.001) via CD44 receptor-mediated endocytosis.

CONCLUSION

This study demonstrated the successful application of HINPs as nanocarriers for delivering ICG to CD44-positive cervical cancer, with improved efficacy in NIR fluorescence imaging.

Oral submucous fibrosis stimulates invasion and epithelial-mesenchymal transition in oral squamous cell carcinoma by activating MMP-2 and IGF-IR

Oral submucous fibrosis (OSF) involves a high risk of malignant transformation and has been implicated in oral cancer. Limited studies have been conducted on the role of OSF in relation to the invasive capabilities and epithelial-mesenchymal transition (EMT) in oral cancer. Herein, we investigated the effects of OSF on the microenvironment of human oral cancer cells. The results showed that the conditioned medium (CM) of fibrotic buccal mucosal fibroblasts (fBMFs) strongly induced the invasion of oral cancer cells and increased the activities of matrix metalloproteinase-2. OSF significantly induced the EMT in oral cancer cells and downregulated epithelial markers, such as E-cadherin, but significantly elevated vimentin, fibronectin, N-cadherin, RhoA, Rac-1 and FAK. Insulin-like growth factor-1 (IGF-1) was elevated in OSF. The protein levels of the IGF-1R were upregulated specifically in fBMF CM treatment for oral cancer cells, and the IGFR gene was confirmed by The Cancer Genome Atlas patient transcriptome data. The Kaplan-Meier curve analysis revealed that patients with oral squamous cell carcinoma and high IGFR expression levels had poorer 5-year survival than those with low IGFR expression (p = 0.004). The fBMF-stimulated EMT cell model may recapture some of the molecular changes during EMT progression in clinical patients with oral cancer.

Kaempferol inhibits the cell migration of human hepatocellular carcinoma cells by suppressing MMP-9 and Akt signaling

Metastasis is the most prevalent cause of cancer-related deaths and treatment failure in patients with hepatocellular carcinoma (HCC). Kaempferol is a natural flavonol belonging to the subgroup of flavonoids and exhibits potent anticancer activities. This study provides molecular evidence on the anti-invasive and anti-migratory effects of kaempferol on human HCC cells. The anti-invasive effect was investigated by applying kaempferol on two human HCC cell lines (Huh-7 and SK-Hep-1). Kaempferol reduced the invasion and migration of Huh-7 and SK-Hep-1 cells by Boyden chamber invasion assay and wound healing assay, respectively. A protease array analysis showed that Matrix Metalloproteinase-9 (MMP-9) was dramatically downregulated in HCC cells after kaempferol treatment. Gelatin zymography and Western blot assay showed that kaempferol reduced the activities and protein expression of MMP-9, respectively. Kaempferol also sufficiently suppressed the phosphorylation of the Akt expression. Overall, kaempferol inhibited the invasive properties of human HCC cells by targeting MMP-9 and Akt pathways. Hence, kaempferol could be used as an adjuvant therapeutic agent for the treatment of human HCC cells.

The Involvement of Natural Polyphenols in the Chemoprevention of Cervical Cancer

From all types of cancer, cervical cancer manages to be in top four most frequent types, with a 6.5% rate of occurrence. The infectious vector that induces the disease, the high-risk Human papillomavirus (HPV), which is a sexually transmitted virus, is capable of transforming the host cell by modulating some of the principal signaling pathways responsible for cell cycle arrest, proliferation, and survival. Fortunately, like other cancer types, cervical cancer can be treated by chirurgical interventions or chemoradiotherapy, but these methods are not exactly the lucky clover of modern medicine because of the adverse effects they have. That is the reason why in the last years the emphasis has been on alternative medicine, more specifically on phytochemicals, as a substantial number of studies showed that diet contributes to cancer prevention and treatment. All these studies are trying to find new chemopreventive agents with less toxicity but high effectiveness both in vitro and in vivo. The aim of this review is to evaluate the literature in order to underline the advantages and disadvantages of polyphenols, a class of dietary compounds, as chemopreventive and chemotherapeutic agents. This review also aims to present polyphenols from different perspectives, starting with mechanisms of action and ending with their toxicity. The bigger picture illustrates that polyphenols have great potential in cervical cancer prevention, with strong effects on gene modulation.

Flavonoids as an effective sensitizer for anti-cancer therapy: insights into multi-faceted mechanisms and applicability towards individualized patient profiles

Cost-efficacy of currently applied treatments is an issue in overall cancer management challenging healthcare and causing tremendous economic burden to societies around the world. Consequently, complex treatment models presenting concepts of predictive diagnostics followed by targeted prevention and treatments tailored to the personal patient profiles earn global appreciation as benefiting the patient, healthcare economy, and the society at large. In this context, application of flavonoids as a spectrum of compounds and their nano-technologically created derivatives is extensively under consideration, due to their multi-faceted anti-cancer effects applicable to the overall cost-effective cancer management, primary, secondary, and even tertiary prevention. This article analyzes most recently updated data focused on the potent capacity of flavonoids to promote anti-cancer therapeutic effects and interprets all the collected research achievements in the frame-work of predictive, preventive, and personalized (3P) medicine. Main pillars considered are: - Predictable anti-neoplastic, immune-modulating, drug-sensitizing effects; - Targeted molecular pathways to improve therapeutic outcomes by increasing sensitivity of cancer cells and reversing their resistance towards currently applied therapeutic modalities.

Molecular Mechanisms of Antiproliferative Effects of Natural Chalcones

Simple Summary

Despite the important progress in cancer treatment in the past decades, the mortality rates in some types of cancer have not significantly decreased. Therefore, the search for novel anticancer drugs has become a topic of great interest. Chalcones, precursors of flavonoid synthesis in plants, have been documented as natural compounds with pleiotropic biological effects including antiproliferative/anticancer activity. This article focuses on the knowledge on molecular mechanisms of antiproliferative action of chalcones and draws attention to this group of natural compounds that may be of importance in the treatment of cancer disease.

Abstract

Although great progress has been made in the treatment of cancer, the search for new promising molecules with antitumor activity is still one of the greatest challenges in the fight against cancer due to the increasing number of new cases each year. Chalcones (1,3-diphenyl-2-propen-1-one), the precursors of flavonoid synthesis in higher plants, possess a wide spectrum of biological activities including antimicrobial, anti-inflammatory, antioxidant, and anticancer. A plethora of molecular mechanisms of action have been documented, including induction of apoptosis, autophagy, or other types of cell death, cell cycle changes, and modulation of several signaling pathways associated with cell survival or death. In addition, blockade of several steps of angiogenesis and proteasome inhibition has also been documented. This review summarizes the basic molecular mechanisms related to the antiproliferative effects of chalcones, focusing on research articles from the years January 2015–February 2021.

Antitumor Effects of Baicalein and Its Mechanism via TGFβ Pathway in Cervical Cancer HeLa Cells

Background

Due to dual-regulating carcinogenesis, the TGFβ pathway is an ideal and alternative tumor target. Natural flavonoids possess the similar structures to estrogen and could exert an important benefit to cervical cancer. The present study aimed to screen the inhibitor of TGFβ pathway from natural flavonoids and evaluate the function and mechanism of the TGFβ pathway inhibitor on cervical cancer.

Materials and Methods

The cervical cancer HeLa cells were firstly treated with different flavonoids and probed by western blot for screening the inhibitor of TGFβ pathway. And then, the effect of the identified inhibitor on cell proliferation was studied by CCK-8 and clone formation assay. Then, RT-PCR and western blot assay were performed to evaluate the effect of identified inhibitor on mTOR/p70S6K pathway, and the cell migration and EMT pathway were also examined using scratching analysis and western blot assay. Finally, the role of TGFβ was assessed via the classic inhibitor of TGFβ/SMAD pathway.

Results

Screening data by western blot assay showed that baicalein displayed the best inhibitor effect on TGFβ expression. CCK-8 and clone formation assay showed that baicalein inhibited the cell proliferation and clone cell number. RT-PCR and western bolt for probing mTOR, p70S6K, and 4EBP1 revealed that baicalein could suppress their expression and phosphorylation. The scratching analysis and western blot assay displayed that baicalein inhibited the cell migration and EMT progression in HeLa. The use of SB431542, a TGFβ inhibitor, revealed that TGFβ was crucial to baicalein-regulating cell proliferation and migration in HeLa cells.

Conclusion

Baicalein, a medicine agent screened from natural flavonoids targeting TGFβ pathway, could suppress mTOR/p70S6K pathway-mediated cell proliferation and EMT pathway-related migration via TGFβ pathway in cervical cancer HeLa cells.

Endothelial Cell Glucose Metabolism and Angiogenesis

Angiogenesis, a process of new blood vessel formation from the pre-existing vascular bed, is a critical event in various physiological and pathological settings. Over the last few years, the role of endothelial cell (EC) metabolism in angiogenesis has received considerable attention. Accumulating studies suggest that ECs rely on aerobic glycolysis, rather than the oxidative phosphorylation pathway, to produce ATP during angiogenesis. To date, numerous critical regulators of glucose metabolism, fatty acid oxidation, and glutamine metabolism have been identified to modulate the EC angiogenic switch and pathological angiogenesis. The unique glycolytic feature of ECs is critical for cell proliferation, migration, and responses to environmental changes. In this review, we provide an overview of recent EC glucose metabolism studies, particularly glycolysis, in quiescent and angiogenic ECs. We also summarize and discuss potential therapeutic strategies that take advantage of EC metabolism. The elucidation of metabolic regulation and the precise underlying mechanisms could facilitate drug development targeting EC metabolism to treat angiogenesis-related diseases.

Erb‑B2 Receptor Tyrosine Kinase 2 is negatively regulated by the p53‑responsive microRNA‑3184‑5p in cervical cancer cells

The oncogenic role of Erb‑B2 Receptor Tyrosine Kinase 2 (ERBB2) has been identified in several types of cancer, but less is known on its function and mechanism of action in cervical cancer cells. The present study employed a multipronged approach to investigate the role of ERBB2 in cervical cancer. ERBB2 and microRNA (miR)‑3184‑5p expression was assessed in patient‑derived cervical cancer biopsy tissues, revealing that higher levels of ERBB2 and lower levels of miR‑3184‑5p were associated with clinicopathological indicators of cervical cancer progression. Furthermore, ERBB2 stimulated proliferation, migration and sphere‑formation of cervical cancer cells in vitro. This effect was mediated by enhanced phosphatidylinositol‑4,5‑bisphosphate 3‑kinase catalytic subunit α activity. Additionally, it was revealed that miR‑3184‑5p directly suppressed ERBB2 in cervical cancer cells. The p53 activator Mithramycin A stimulated p53 and miR‑3184‑5p expression, thereby lowering the levels of ERBB2 and attenuating proliferation, migration and sphere‑formation of cervical cancer cells. In conclusion, the findings of the present study suggested ERBB2 as an oncogenic protein that may promote invasiveness in cervical cancer cells. Treatment of cervical cancer cells with the p53 activator Mithramycin A restored the levels of the endogenous ERBB2 inhibitor miR‑3184‑5p and may represent a novel treatment strategy for cervical cancer.

Gossypol Reduces Metastasis and Epithelial-Mesenchymal Transition by Targeting Protease in Human Cervical Cancer

Metastasis is the most prevalent cause of cancer-associated deaths amongst patients with cervical cancer. Epithelial-mesenchymal transition (EMT) is essential for carcinogenesis, and it confers metastatic properties to cancer cells. Gossypol is a natural polyphenolic compound with anti-inflammation, anti-oxidant, and anticancer activities. In this study, we investigated the antimetastatic and antitumour effects of gossypol on human cervical cancer cells (HeLa and SiHa cells). Gossypol exerted a strong inhibition effect on the migration and invasion of human cervical cancer cells. It reduced the focal adhesion kinase (FAK) pathway-mediated expression of matrix metalloproteinase-2 and urokinase-type plasminogen activator, subsequently inhibiting the invasion of SiHa cells. In addition, gossypol reversed EMT induced by transforming growth factor beta 1 (TGF-[Formula: see text]1) and up-regulated epithelial markers, such as E-cadherin but significantly suppressed Ras homolog family member (Rho)A, RhoB, and p-Samd3. The tail vein injection model showed that gossypol treatment via oral gavage reduced lung metastasis. Gossypol also decreased tumour growth in vivo in the nude mouse xenograft model. All these findings suggest that gossypol suppressed the invasion and migration of human cervical cancer cells by targeting the FAK signaling pathway and reversing TGF-[Formula: see text]1-induced EMT. Hence, gossypol warrants further attention for basic mechanistic studies and drug development.

The Role of Autophagy in Gastric Cancer Chemoresistance: Friend or Foe?

Gastric cancer is the third most common cause of cancer-related death worldwide. Drug resistance is the main inevitable and vital factor leading to a low 5-year survival rate for patients with gastric cancer. Autophagy, as a highly conserved homeostatic pathway, is mainly regulated by different proteins and non-coding RNAs (ncRNAs) and plays dual roles in drug resistance of gastric cancer. Thus, targeting key regulatory nodes in the process of autophagy by small molecule inhibitors or activators has become one of the most promising strategies for the treatment of gastric cancer in recent years. In this review, we provide a systematic summary focusing on the relationship between autophagy and chemotherapy resistance in gastric cancer. We comprehensively discuss the roles and molecular mechanisms of multiple proteins and the emerging ncRNAs including miRNAs and lncRNAs in the regulation of autophagy pathways and gastric cancer chemoresistance. We also summarize the regulatory effects of autophagy inhibitor and activators on gastric cancer chemoresistance. Understanding the vital roles of autophagy in gastric cancer chemoresistance will provide novel opportunities to develop promising therapeutic strategies for gastric cancer.

Leading the invasion: The role of Cathepsin S in the tumour microenvironment

Elevated expression of the cysteine protease Cathepsin S has been correlated with a number of different cancer types in recent years. As tools have been developed to enable more accurate examination of individual cathepsin species, our knowledge and appreciation of the role that this protease plays in facilitating cancer has increased exponentially. This review focuses on our current understanding of the role of Cathepsin S within tumours and the surrounding microenvironment. While various publications have shown that Cathepsin S can be derived from tumour cells themselves, a plethora of more recent studies have identified that Cathepsin S can also be derived from other cell types within the tumour microenvironment including endothelial cells, macrophages and T cells. Furthermore, specific proteolytic substrates cleaved by Cathepsin S have also been identified which have reinforced our hypothesis that this protease facilitates key steps within tumours leading to their invasion, angiogenesis and metastasis.

Flavonoids in Cancer Metastasis

Metastasis represents a serious complication in the treatment of cancer. Flavonoids are plant secondary metabolites exerting various health beneficiary effects. The effects of flavonoids against cancer are associated not only with early stages of the cancer process, but also with cancer progression and spread into distant sites. Flavonoids showed potent anti-cancer effects against various cancer models in vitro and in vivo, mediated via regulation of key signaling pathways involved in the migration and invasion of cancer cells and metastatic progression, including key regulators of epithelial-mesenchymal transition or regulatory molecules such as MMPs, uPA/uPAR, TGF-β and other contributors of the complex process of metastatic spread. Moreover, flavonoids modulated also the expression of genes associated with the progression of cancer and improved inflammatory status, a part of the complex process involved in the development of metastasis. Flavonoids also documented clear potential to improve the anti-cancer effectiveness of conventional chemotherapeutic agents. Most importantly, flavonoids represent environmentally-friendly and cost-effective substances; moreover, a wide spectrum of different flavonoids demonstrated safety and minimal side effects during long-termed administration. In addition, the bioavailability of flavonoids can be improved by their conjugation with metal ions or structural modifications by radiation. In conclusion, anti-cancer effects of flavonoids, targeting all phases of carcinogenesis including metastatic progression, should be implemented into clinical cancer research in order to strengthen their potential use in the future targeted prevention and therapy of cancer in high-risk individuals or patients with aggressive cancer disease with metastatic potential.

Antimetastatic Effects of Sesamin on Human Head and Neck Squamous Cell Carcinoma through Regulation of Matrix Metalloproteinase-2

Background: Sesamin is a lignin present in sesame oil from the bark of Zanthoxylum spp. Sesamin reportedly has anticarcinogenic potential and exerts anti-inflammatory effects on several tumors. Hypothesis/Purpose: However, the effect of sesamin on metastatic progression in human head and neck squamous carcinoma (HNSCC) remains unknown in vitro and in vivo; hence, we investigated the effect of sesamin on HNSCC cells in vitro. Methods and Results: Sesamin-treated human oral cancer cell lines FaDu, HSC-3, and Ca9-22 were subjected to a wound-healing assay. Furthermore, Western blotting was performed to assess the effect of sesamin on the expression levels of matrix metalloproteinase (MMP)-2 and proteins of the MAPK signaling pathway, including p-ERK1/2, P-p38, and p-JNK1/2. In addition, we investigated the association between MMP-2 expression and the MAPK pathway in sesamin-treated oral cancer cells. Sesamin inhibited cell migration and invasion in FaDu, Ca9-22, and HSC-3 cells and suppressed MMP-2 at noncytotoxic concentrations (0 to 40 μM). Furthermore, sesamin significantly reduced p38 MAPK and JNK phosphorylation in a dose-dependent manner in FaDu and HSC-3 cells. Conclusions: These results indicate that sesamin suppresses the migration and invasion of HNSCC cells by regulating MMP-2 and is thus a potential antimetastatic agent for treating HNSCC.

Dihydrochalcones: Methods of Acquisition and Pharmacological Properties-A First Systematic Review

Dihydrochalcones are a class of secondary metabolites, for which demand in biological and pharmacological applications is still growing. They posses several health-endorsing properties and, therefore, are promising candidates for further research and development. However, low content of dihydrochalcones in plants along with their low solubility and bioavailability restrict the development of these compounds as clinical therapeutics. Therefore, chemomicrobial and enzymatic modifications are required to expand their application. This review aims at analyzing and summarizing the methods of obtaining dihydrochalcones and of presenting their pharmacological actions that have been described in the literature to support potential future development of this group of compounds as novel therapeutic drugs. We have also performed an evaluation of the available literature on beneficial effects of dihydrochalcones with potent antioxidant activity and multifactorial pharmacological effects, including antidiabetic, antitumor, lipometabolism regulating, antioxidant, anti-inflammatory, antibacterial, antiviral, and immunomodulatory ones. In addition, we provide useful information on their properties, sources, and usefulness in medicinal chemistry.

Chrysophanol exhibits anti-cancer activities in lung cancer cell through regulating ROS/HIF-1a/VEGF signaling pathway

In the present study, we explored the anti-tumor and anti-angiogenesis effects of chrysophanol, and to investigate the underlying mechanism of the chrysophanol on anti-tumor and anti-angiogenesis in human lung cancer. The viability of cells was measured by CCK-8 assay, cell apoptosis was measured by Annexin-FITC/PI staining assay, and the cell migration and invasion were analyzed by wound-healing assay and transwell assay. ROS generation and mitochondrial membrane potential were analyzed by DCFH-DA probe and mitochondrial staining kit. Angiogenesis was analyzed by tube formation assay. The expression of CD31 was analyzed by immunofluorescence. The levels of proteins were measured by western blot assay. The anti-tumor effects of chrysophanol in vivo were detected by established xenograft mice model. In this study, we found that the cell proliferation, migration, invasion, tube formation, the mitochondrial membrane potential, and the expression of CD31 were inhibited by chrysophanol in a dose-dependent manner, but cell apoptotic ratios and ROS levels were increased by chrysophanol in a dose-dependent manner. Furthermore, the effects of chrysophanol on A549, H738, and HUVEC cell apoptotic rates were reversed by the ROS inhibitor NAC. Besides, the effects of chrysophanol on HUVEC cell tube formation were reversed by the HIF-1α inhibitor KC7F2 and the VEGF inhibitor axitinib in vitro. Moreover, tumor growth was reduced by chrysophanol, and the expression of CD31, CD34, and angiogenin was suppressed by chrysophanol in vivo. Our finding demonstrated that chrysophanol is a highly effective and low-toxic drug for inhibition of tumor growth especially in high vascularized lung cancer.