Quercetin suppresses the tumorigenesis of oral squamous cell carcinoma by regulating microRNA-22/WNT1/β-catenin axis

OSR1 suppresses oral squamous cell carcinoma proliferation and migration via the AXIN2/β-catenin pathway

OBJECTIVES

The odd-skipped related transcription factor 1 (OSR1) gene exerts distinct regulatory effects on tumorigenesis and development in various cancer types. However, the precise role of OSR1 in oral squamous cell carcinoma (OSCC) remains to be elucidated.

METHODS

GEPIA 2 and TCGA databases were utilized to analyze the OSR1 expression in head and neck squamous cell carcinoma (HNSC) patients and its impact on prognosis. Hematoxylin-eosin staining, immunohistochemistry, immunofluorescence, western blotting, and RT-qPCR were employed to detect the OSR1 expression in OSCC tissues and cells. Lentivirus transfection was utilized for overexpression and downexpression of OSR1 in OSCC. CCK8 cell proliferation assay, colony formation and cell scratch assay were conducted to investigate the effects of OSR1 on biological behavior of OSCC cells. Western blotting and RT-qPCR were applied to investigate the regulatory mechanism of OSR1 on AXIN2/β-catenin signaling pathway.

RESULTS

OSR1 expression was significantly decreased in HNSC patients, OSCC tissues and cells, leading to a decrease in 5-year survival rate. OSR1 overexpression inhibited the proliferation and migration of OSCC cells, and the AXIN2/β-catenin signaling pathway was inhibited. Silencing OSR1 had the opposite effect.

CONCLUSIONS

OSR1 functioned as a tumor suppressor gene in OSCC proliferation and migration by regulating the AXIN2/β-catenin signaling pathway.

Phytochemicals and their Nanoformulations for Overcoming Drug Resistance in Head and Neck Squamous Cell Carcinoma

BACKGROUND

Drug resistance remains a significant challenge in the treatment of head and neck squamous cell carcinoma (HNSCC), leading to therapeutic failure and poor patient prognosis. Numerous mechanisms, including drug efflux pumps, altered tumor microenvironment (TME), and dysregulated cell death pathways, contribute to the development of resistance against conventional chemotherapeutic agents, immunotherapy, and targeted therapies. As resistance to traditional treatments continues to emerge, there is an urgent need for innovative therapeutic strategies to overcome these challenges. Phytochemicals are naturally occurring bioactive compounds and have demonstrated remarkable potential in targeting multiple resistance mechanisms simultaneously.

METHOD

This review comprehensively overviews the current understanding of drug resistance mechanisms in HNSCC and explores innovative strategies utilizing phytochemicals and their nanoformulations to overcome these resistance mechanisms, with a particular focus on recent developments and future perspectives in this field.

RESULTS AND DISCUSSION

Phytochemicals with anticancer properties include a wide range of herbal-derived molecules such as flavonoids, stilbenes, curcuminoids, alkaloids, traditional Chinese medicine, and others. These compounds can modulate ATP-binding cassette transporters, reverse epithelial-to-mesenchymal transition (EMT), target cancer stem cells (CSCs), and regulate various signaling pathways involved in drug resistance. The integration of phytochemicals into advanced nanoformulation systems has also shown a remarkable improvement in enhancing their bioavailability, stability, and targeted delivery to the TME, potentially improving their therapeutic efficacy. Furthermore, the combination of phytochemicals with conventional chemotherapeutic agents, targeted molecular therapy, and immune checkpoint inhibitors (ICIs) has exhibited synergistic effects, offering a promising approach to restoring drug sensitivity in resistant HNSCC cells.

CONCLUSION

Phytochemicals and their nanoformulations may improve response of HNSCC to therapy by alleviating drug resistance.

Therapeutic effects of quercetin in oral cancer therapy: a systematic review of preclinical evidence focused on oxidative damage, apoptosis and anti-metastasis

OBJECTIVE

Oral malignancies are among the common head and neck cancers. Various therapeutic modalities are used for targeting oral cancers. It was shown that quercetin (a flavonoid) has an anti-cancer effect on different cancers. In the current study, the anti-cancer potentials of quercetin against oral cancer cells were summarized.

METHODS

The current systematic review was conducted in accordance with the PRISMA guideline for the identification of relevant studies in various electronic databases up to April 2023. After reviewing and screening 193 articles, 18 were chosen for this study based on our inclusion and exclusion criteria.

RESULTS

It was shown that quercetin significantly reduced cancer cell proliferation, cell viability, tumor volume, invasion, metastasis and migration. This anti-cancer agent induced oxidative stress and apoptosis in the cancer cells. Quercetin treatment could also induce some biochemical alterations in the cancer cells.

CONCLUSION

According to the results, it can be mentioned that quercetin administration has an anti-cancer effect against oral cancer cells. This agent exerts its anticancer effects via reduced cell viability and different mechanisms, including induce oxidative damage, apoptosis, and reduced invasion and metastasis. However, suggesting the use of quercetin as a therapeutic agent of oral cancer patients requires further clinical studies due to its poor absorption rates, and the exact molecular mechanisms are still not well understood.

Anticancer Potential of Quercetin on Oral Squamous Cell Carcinoma: A Scoping Review and Molecular Docking

Oral squamous cell carcinoma (OSCC) is a type of cancer that has a low survival rate and high recurrence and metastasis rates. To date, there is still no effective treatment for OSCC. Various types of cancer, including OSCC, have reported quercetin to act as an anticancer agent, but there is no clear research data on how it may affect OSCC. To determine the anticancer potential of quercetin in OSCC, we conducted a scoping review, and to determine the interaction of quercetin with one of the proteins that plays a role in carcinogenesis, namely, BCL-2, we conducted molecular docking. The scoping review process was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews. The scoping review was searched by collecting articles related to the research topic in Google Scholar, PubMed, ScienceDirect, Cochrane, and EBSCOhost databases. All of the literature records found during the search were imported into the Mendeley software to remove duplication. Nine studies were generated after the titles and abstracts were reviewed according to the inclusion and exclusion criteria. After the full-text screening, no studies were excluded, leaving nine publications determined to be eligible for inclusion in the scoping review. Quercetin showed effects on inhibiting cancer invasion, migration, proliferation, and many protein expressions, as well as increasing cell apoptosis. Molecular docking was done for quercetin and BCl-2 protein. Doxorubicin was utilized as a comparison ligand. The in silico study was utilized using AutoDock Vina, AutoDock Tools 1.5.6, Biovia Discovery Studio 2021, and PyMol. Molecular docking indicated quercetin has a strong binding affinity with BCl-2 protein (ΔG -7.2 kcal/mol). Both scoping review and molecular docking revealed that quercetin is a promising candidate for anticancer agent.

Effects of quercetin on mineralized dental tissues: A scoping review

OBJECTIVE

This scoping review (SR) aimed to investigate the impact of quercetin on mineralized dental tissues intended to be used in preventive and restorative dentistry.

METHODS

This SR was conducted following the PRISMA-ScR statement. A comprehensive search was performed across databases for articles published up to March 2024. Eligible studies included in vitro and in situ studies and evaluating the potential therapeutic effects of quercetin on dental enamel and dentin. Data were extracted, and synthesis of study findings was conducted.

RESULTS

Out of the 2322 records screened, 22 studies were included in the review. Quercetin, in solution or into dental materials increased the bond strength to enamel and dentin. Additionally, quercetin also enhanced the bond strength of enamel after bleaching. Co-administration of quercetin with fluoride prevented erosive wear and inhibited the proteolytic activity in dentin more effectively than either agent alone. Hardness and modulus of elasticity was higher in dentin treated with quercetin compared to placebo. Reduction of nanoleakage at the composite-dentin interface was reduced in the presence of quercetin as a solution or incorporated into dental adhesives.

CONCLUSIONS

Quercetin exhibits promising therapeutic effects on mineralized dental tissues, including remineralization and enhancement of bond strength. It shows potential as a multifunctional agent for improving the longevity and effectiveness of dental biomaterials, as well as in preventing erosion and dental caries. However, as these conclusions are largely drawn from lab-based (in vitro) studies, further research, including clinical trials, is needed to fully explore its therapeutic potential and applications in dentistry.

Quercetin and microRNA Interplay in Apoptosis Regulation: A New Therapeutic Strategy for Cancer?

Cancer is known as a global problem for the health and economy. Following cancer onset, apoptosis is the primary mechanism countering the tumor cells' growth. Most anticancer agents initiate apoptosis to remove tumor cells. Phytochemicals have appeared as a beneficial treatment option according to their less adverse effects. In recent decades, quercetin has been highlighted due to its high pharmacological benefits, and various literature has suggested it as a potential anti-proliferative agent against different kinds of cancers. The microRNAs (miRNAs) play key roles in cancer treatment, progression, and apoptosis. This review reviewed the effect of quercetin on miRNAs contributing to the induction or inhibition of apoptosis in cancers.

Modulation of Long Non-coding RNAs and MicroRNAs by Quercetin as a Potential Therapeutical Approach in Cancer: A Comprehensive Review

Cancer can take years to develop, both at its beginning and during its development. All typical epithelial cancers have a long latency period, sometimes 20 years or more, and if they are clinically detected, distinct genes may include infinite mutations. Long non-coding RNAs (LncRNAs) are a subset of RNAs that regulate many biological processes, including RNA processing, epigenetic control, and signal transduction. Current studies show that lncRNAs, which are dysregulated in cancer, play a significant function in the growth and spread of the illness. LncRNAs have been connected to the overexpression of specific proteins that function in tumors' spread and growth. Moreover, through translational inhibition, microRNAs (miRNAs) regulates gene expression sequence specifically. Apart from that, non-coding RNAs known as miRNAs, with a length of around 22 nucleotides, controls gene expressions in a sequence-specific way either by preventing translation or degrading messenger RNA (mRNA). Quercetin appears to have a significant role in altering miRNA and lncRNA expression, which is linked to variations in the production of oncogenes, tumor suppressors, and proteins produced from cancer. Quercetin may change the earliest epigenetic modifications related to cancer prevention in addition to its usual antioxidant or anti-inflammatory effects. It would be beneficial to have more in-depth information on how Quercetin modulates miRNAs and lncRNAs to use it as a cancer therapeutic strategy. Here, we go through what is known about Quercetin's potential to modulate miRNAs and lncRNAs in various malignancies.

Application of Natural Medicinal Plants Active Ingredients in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the most common malignant cancer of the head and neck, with high morbidity and mortality, ranking as the sixth most common cancer in the world. The treatment of OSCC is mainly radiotherapy, chemotherapy and surgery, however, the prognosis of patients is still poor and the recurrence rate is high. This paper reviews the range of effects of natural medicinal plant active ingredients (NMPAIs) on OSCC cancer, including the types of NMPAIs, anti-cancer mechanisms, involved signaling pathways, and clinical trials. The NMPAIs include terpenoids, phenols, flavonoids, glycosides, alkaloids, coumarins, and volatile oils. These active ingredients inhibit proliferation, induce apoptosis and autophagy, inhibit migration and invasion of OSCC cells, and regulate cancer immunity to exert anti-cancer effects. The mechanism involves signaling pathways such as mitogen-activated protein kinase, phosphatidylinositol 3 kinase/protein kinase B, nuclear factor kappa B, miR-22/WNT1/β-catenin and Nrf2/Keap1. Clinically, NMPAIs can inhibit the growth of OSCC, and the combined drug is more effective. Natural medicinal plants are promising candidates for the treatment of OSCC.

Quercetin induces ferroptosis by inactivating mTOR/S6KP70 pathway in oral squamous cell carcinoma

Although recent studies increasingly suggest the potential anti-cancer effect of quercetin, the exact underlying mechanism remains poorly demonstrated in oral squamous cell carcinoma (oSCC). Therefore, our research explored the impacts of quercetin on the ferroptosis and mTOR/S6KP70 axis in oSCC cell lines. After treating oSCC cells with quercetin or indicated compounds and transfection with SLC7A11- or S6KP70-overexpressing plasmid, cell viability was detected by CCK-8 assay. The level of ferroptosis in oSCC cells was assessed by measuring ROS and GSH levels. The activation of mTOR/S6KP70 axis was assessed by Western blotting. Quercetin promoted ferroptosis in an mTOR/S6KP70-dependent manner to inhibit tumor growth in oSCC cells. Mechanistically, we revealed that quercetin induced lipid peroxidation and reduced GSH levels by repressing SLC7A11 expression in oSCC cells. Specifically, the effects of quercetin on ferroptosis and mTOR and S6KP70 phosphorylation were partially blocked by both mTOR agonist and S6KP70 overexpression. Moreover, mTOR inhibitor promoted ferroptosis in quercetin-treated oSCC cells. Our findings showed that ferroptosis may be a new anti-tumor mechanism of quercetin. Additionally, we identified that quercetin can target mTOR/S6KP70 cascade to inhibit the growth of oSCC cells.

High expression of ACTL6A leads to poor prognosis of oral squamous cell carcinoma patients through promoting malignant progression

OBJECTIVE

The aim was to research ACTL6A's role in oral squamous cell carcinoma (OSCC).

METHODS

OSCC and normal samples were obtained from patients and public databases. GSEA was performed. CIBERSORT was utilized to analyze immune landscape. Kaplan-Meier survival analysis and multivariate Cox regression analysis were conducted. After knocking down ACTL6A, we performed MTT assay, transwell assays, and flow cytometry to detect the impact of knockdown.

RESULTS

ACTL6A expressed higher in OSCC samples than normal samples. The CNV and mutation rate of TP53 was higher in ACTL6A high-expression group. TFs E2F7 and TP63 and miRNA hsa-mir-381 were significantly related to ACTL6A. ACTL6A could influence immune microenvironment of OSCC. Knockdown of ACTL6A inhibited OSCC cells' proliferation, migration, and invasion. ACTL6A was able to predict OSCC prognosis independently.

CONCLUSION

ACTL6A expressed higher in OSCC than normal samples and it could be used as an independent prognostic marker in OSCC patients.

Quercetin, a Flavonoid with Great Pharmacological Capacity

Quercetin is a flavonoid with a low molecular weight that belongs to the human diet's phenolic phytochemicals and nonenergy constituents. Quercetin has a potent antioxidant capacity, being able to capture reactive oxygen species (ROS), reactive nitrogen species (RNS), and reactive chlorine species (ROC), which act as reducing agents by chelating transition-metal ions. Its structure has five functional hydroxyl groups, which work as electron donors and are responsible for capturing free radicals. In addition to its antioxidant capacity, different pharmacological properties of quercetin have been described, such as carcinostatic properties; antiviral, antihypertensive, and anti-inflammatory properties; the ability to protect low-density lipoprotein (LDL) oxidation, and the ability to inhibit angiogenesis; these are developed in this review.

Network pharmacology prediction and molecular docking-based strategy to explore the potential mechanism of Radix Astragali against hypopharyngeal carcinoma

To explore the anti-tumor effects of Radix Astragali on hypopharyngeal carcinoma and its mechanism. We have bioinformatically analyzed the potential targets of Radix Astragali and predicted the molecular mechanism of Radix Astragali treating of hypopharyngeal carcinoma. The binding process of the hub targets that could prolong the survival time of hypopharyngeal cancer patients with Radix Astragali was simulated by molecular docking. The results showed that 17 out of 36 hub targets could effectively improve the 5-year survival rate of hypopharyngeal cancer patients. Radix Astragali acts on hypopharyngeal carcinoma by regulating a signaling network formed by hub targets connecting multiple signaling pathways and is expected to become a drug for treating and prolonging hypopharyngeal carcinoma patients' survival time.

Decoding the role of miRNAs in oral cancer pathogenesis: A focus on signaling pathways

Oral cancer (OC) is the predominant type originating in the head and neck region. The incidence of OC is mostly associated with behavioral risk factors, including tobacco smoking and excessive alcohol intake. Additionally, there is a lower but still significant association with viral infections such as human papillomaviruses and Epstein-Barr viruses. Furthermore, it has been observed that heritable genetic variables are linked to the risk of OC, in addition to the previously mentioned acquired risk factors. The current absence of biomarkers for OC diagnosis contributes to the frequent occurrence of advanced-stage diagnoses among patients. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs, and circular RNAs, have been observed to exert a significant effect on the transcriptional control of target genes involved in cancer, either through direct or indirect mechanisms. miRNAs are a class of short ncRNAs that play a role in regulating gene expression by enabling mRNA degradation or translational repression at the post-transcriptional phase. miRNAs are known to play a fundamental role in the development of cancer and the regulation of oncogenic cell processes. Notch signaling, PTEN/Akt/mTOR axis, KRAS mutation, JAK/STAT signaling, P53, EGFR, and the VEGFs have all been linked to OC, and miRNAs have been shown to have a role in all of these. The dysregulation of miRNA has been identified in cases of OC and is linked with prognosis.

Regulation of main ncRNAs by polyphenols: A novel anticancer therapeutic approach

BACKGROUND

Plant polyphenols have shown promising applications in oncotherapy. Increasing evidence reveals that polyphenols possess the antitumor potential for multiple cancers. Non-coding RNAs (ncRNAs), mainly including small ncRNAs (microRNA) and long ncRNAs (lncRNAs), play critical roles in cancer initiation and progression.

PURPOSE

To establish the modulation of ncRNAs by polyphenols as a novel and promising approach in anticancer treatment.

STUDY DESIGN

The present research employed ncRNA, miRNA, lncRNA, and regulatory mechanism as keywords to retrieve the literature from PubMed, Web of Science, Science direct, and Google Scholar, in a 20-year period from 2003 to 2023. This study critically reviewed the current literature and presented the regulation of prominent ncRNAs by polyphenols. A comprehensive total of 169 papers were retrieved on polyphenols and their related ncRNAs in cancers.

RESULTS

NcRNAs, mainly including miRNA and lncRNA, play critical roles in cancer initiation and progression, which are potential modulatory targets of bioactive polyphenols, such as resveratrol, genistein, curcumin, EGCG, quercetin, in cancer management. The mechanism involved in polyphenol-mediated ncRNA regulation includes epigenetic and transcriptional modification, and post-transcriptional processing.

CONCLUSION

Regulatory ncRNAs are potential therapeutic targets of bioactive polyphenols, and these phytochemicals could modulate the level of these ncRNAs directly and indirectly. A better comprehension of the ncRNA regulation by polyphenols in cancers, their functional outcomes on tumor pathophysiology and regulatory molecular mechanisms, may be helpful to develop effective strategies to fight the devastating disease.

Using network pharmacological analysis and molecular docking to investigate the mechanism of action of quercetin's suppression of oral cancer

OBJECTIVE

This investigation seeks to explore the mechanism of quercetin in oral cancer by incorporating network pharmacology analysis and molecular docking.

METHODS

First, we use the network pharmacology analysis to discover possible core targets for quercetin and oral cancer. We subsequently utilized the docking of molecules techniques to calculate the affinities of critical targets and quercetin for verification.

RESULTS

TCMSP and the Swiss Target Prediction database found 190 quercetin action targets, while GeneCards, OMIM, PharmGkb, and the Therapeutic Target Database found 8971 oral cancer-related targets. Venny 2.1.0 online software conducted an intersection analysis of quercetin-related target information with information about oral cancer, and 172 putative quercetin-anti-oral cancer targets were examined. Six prospective core targets for quercetin treatment of oral cancer were identified from the PPI network topology analysis of 172 putative therapeutic targets. These targets include AKT1, PIK3R1, MYC, HIF1A, SRC, and HSP90AA1. GO enrichment function analysis showed that 2372 biological processes, 98 cell components, and 201 molecular functions were involved. Through enrichment analysis of the KEGG pathway, 172 signal pathways were obtained. A few examples are PI3K-AKT, HIF-1, IL-17, and other signaling pathways. The molecular docking scores of quercetin and the primary therapeutic targets AKT1, HIF1A, HSP90AA1, MYC, PIK3R1, and SRC are all less than -0.7 points, demonstrating good compatibility between the medicine and small molecules and suggesting that quercetin may affect oral cancer through the primary target.

CONCLUSION

This study explores quercetin's mechanism and possible targets for oral cancer treatment, offering novel approaches. Quercetin may be a multitarget medication against oral cancer in the future.

Epigallocatechin-3-gallate and cancer: focus on the role of microRNAs

MicroRNAs (miRNAs) are a group of small non-coding RNAs that affect gene expression. The role of miRNAs in different types of cancers has been published and it was shown that several miRNAs are inappropriately expressed in different cancers. Among the mechanisms that can cause this lack of proper expression are epigenetics, chromosomal changes, polymorphisms or defects in processing proteins. Recent research shows that phytochemicals, including epigallocatechin-3-gallate (EGCG), exert important epigenetic-based anticancer effects such as pro-apoptotic or anti proliferative through miRNA gene silencing. Given that EGCG is able to modulate a variety of cancer-related process i.e., angiogenesis, proliferation, metastasis and apoptosis via targeting various miRNAs such as let-7, miR-16, and miR-210. The discovery of new miRNAs and the differences observed in their expression when exposed to EGCG provides evidence that targeting these miRNAs may be beneficial as a form of treatment. In this review, we aim to provide an overview, based on current knowledge, on how phytochemicals, including epigallocatechin-3-gallate, can be considered as potential miRNAs modulator to improve efficacy of current cancer treatments.

Role of Stromal Fibroblast-Induced WNT7A Associated with Cancer Cell Migration Through the AKT/CLDN1 Signaling Axis in Oral Squamous Cell Carcinoma

Wnt signaling plays a crucial role in the progression of various cancers, including oral squamous cell carcinoma (OSCC). However, the tumor microenvironment (TME) regulating Wnt signaling has not yet been fully elucidated. In this study, we investigated whether cancer-associated fibroblasts (CAFs), the primary components of the TME, activate Wnt signaling and promote tumor progression in OSCC. We conducted a Transwell coculture assay using human OSCC cell lines and normal human dermal fibroblasts (NHDFs). NHDFs stimulated WNT7A expression in several OSCC cell lines, especially HO-1-N-1 and HSC-5. An immunohistochemical study using 122 human OSCC samples indicated that high WNT7A expression in tumor cells was significantly associated with invasion depth and poor prognosis. Moreover, WNT7A expression in OSCC cells was positively correlated with α-smooth muscle actin expression in CAFs. WNT7A knockdown in OSCC cells demonstrated that OSCC cells cocultured with NHDFs significantly promoted tumor cell migration and invasion, which was dependent on WNT7A expression in OSCC cells. We also isolated HSC-5 cells from the coculture and conducted microarray analysis to investigate the factors that promote tumor progression induced by WNT7A. Among the various differentially expressed genes, we identified a downregulated gene encoding CLDN1 and confirmed that WNT7A negatively regulated CLDN1 expression in OSCC cells and CLDN1 knockdown in OSCC cells promoted their migration. Phosphokinase array analysis showed that WNT7A activates protein kinase B (AKT) phosphorylation. Activating AKT signaling using the SC79 agonist induced CLDN1 downregulation in OSCC cells. In the coculture assay, the AKT inhibitor MK2206 significantly recovered CLDN1 expression downregulated by WNT7A, resulting in OSCC cell migration suppression. These results suggest that CAFs stimulate OSCC cells to produce WNT7A, following CLDN1 expression downregulation by activating AKT signaling, promoting cancer cell migration. These findings highlight the importance of molecular therapies targeting the TME in OSCC.

Tumor microenvironment remodeling in oral cancer: Application of plant derived-natural products and nanomaterials

Oral cancers consist of squamous cell carcinoma (SCC) and other malignancies in the mouth with varying degrees of invasion and differentiation. For many years, different modalities such as surgery, radiation therapy, and classical chemotherapy drugs have been used to control the growth of oral tumors. Nowadays, studies have confirmed the remarkable effects of the tumor microenvironment (TME) on the development, invasion, and therapeutic resistance of tumors like oral cancers. Therefore, several studies have been conducted to modulate the TME in various types of tumors in favor of cancer suppression. Natural products are intriguing agents for targeting cancers and TME. Flavonoids, non-flavonoid herbal-derived molecules, and other natural products have shown promising effects on cancers and TME. These agents, such as curcumin, resveratrol, melatonin, quercetin and naringinin have demonstrated potency in suppressing oral cancers. In this paper, we will review and discuss about the potential efficacy of natural adjuvants on oral cancer cells. Furthermore, we will review the possible therapeutic effects of these agents on the TME and oral cancer cells. Moreover, the potential of nanoparticles-loaded natural products for targeting oral cancers and TME will be reviewed. The potentials, gaps, and future perspectives for targeting TME by nanoparticles-loaded natural products will also be discussed.

A snapshot of miRNAs in oral squamous cell carcinoma: Difference between cancer cells and corresponding normal cells

Oral squamous cell carcinoma (OSCC) constitutes the most aggressive tumors of the oral cavity and is one of the leading causes of cancer mortality worldwide. Although recent clinical treatment strategies have improved the survival rate, the outcome of OSCC patients still remains dismal because of the lack of efficient diagnostic and treatment tools. As one of the main actors of OSCC scenario, microRNAs (miRNAs) are involved in triggering, progression and metastasis through the regulation of various cancer-related signaling pathways. Identification followed by precise study of the biology and mechanism of action of miRNAs will greatly help to provide valuable insights regarding OSCC development and can be considered as an anti-OSCC target. In the current review, we have provided a focused summary of the latest published papers on the role of miRNAs in apoptosis, cell cycle, proliferation, EMT and metastasis of OSCC as well as the role of long noncoding RNAs in the modulation of miRNAs in OSCC.

Insights on the Role of Polyphenols in Combating Cancer Drug Resistance

Chemotherapy resistance is still a serious problem in the treatment of most cancers. Many cellular and molecular mechanisms contribute to both inherent and acquired drug resistance. They include the use of unaffected growth-signaling pathways, changes in the tumor microenvironment, and the active transport of medicines out of the cell. The antioxidant capacity of polyphenols and their potential to inhibit the activation of procarcinogens, cancer cell proliferation, metastasis, and angiogenesis, as well as to promote the inhibition or downregulation of active drug efflux transporters, have been linked to a reduced risk of cancer in epidemiological studies. Polyphenols also have the ability to alter immunological responses and inflammatory cascades, as well as trigger apoptosis in cancer cells. The discovery of the relationship between abnormal growth signaling and metabolic dysfunction in cancer cells highlights the importance of further investigating the effects of dietary polyphenols, including their ability to boost the efficacy of chemotherapy and avoid multidrug resistance (MDR). Here, it is summarized what is known regarding the effectiveness of natural polyphenolic compounds in counteracting the resistance that might develop to cancer drugs as a result of a variety of different mechanisms.

Molecular signaling in cancer stem cells of tongue squamous cell carcinoma: Therapeutic implications and challenges

Head and neck squamous cell carcinoma is the seventh most common cancer worldwide with high mortality rates. Amongst oral cavity cancers, tongue carcinoma is a very common and aggressive oral cavity carcinoma. Despite the implementation of a multimodality treatment regime including surgical intervention, chemo-radiation as well as targeted therapy, tongue carcinoma shows a poor overall 5-year survival pattern, which is attributed to therapy resistance and recurrence of the disease. The presence of a rare population, i.e., cancer stem cells (CSCs) within the tumor, are involved in therapy resistance, recurrence, and distant metastasis that results in poor survival patterns. Therapeutic agents targeting CSCs have been in clinical trials, although they are unable to reach into therapy stage which is due to their failure in trials. A more detailed understanding of the CSCs is essential for identifying efficient targets. Molecular signaling pathways, which are differentially regulated in the CSCs, are one of the promising targets to manipulate the CSCs that would provide an improved outcome. In this review, we summarize the current understanding of molecular signaling associated with the maintenance and regulation of CSCs in tongue squamous cell carcinoma in order to emphasize the need of the hour to get a deeper understanding to unravel novel targets.

miRNAs as potential game-changers in head and neck cancer: Future clinical and medicinal uses

Head and neck cancers (HNCs) are a group of heterogeneous tumors formed most frequently from epithelial cells of the larynx, lips, oropharynx, nasopharynx, and mouth. Numerous epigenetic components, including miRNAs, have been demonstrated to have an impact on HNCs characteristics like progression, angiogenesis, initiation, and resistance to therapeutic interventions. The miRNAs may control the production of numerous genes linked to HNCs pathogenesis. The roles that miRNAs play in angiogenesis, invasion, metastasis, cell cycle, proliferation, and apoptosis are responsible for this impact. The miRNAs also have an impact on crucial HNCs-related mechanistic networks like the WNT/β-catenin signaling, PTEN/Akt/mTOR pathway, TGFβ, and KRAS mutations. miRNAs may affect how the HNCs respond to treatments like radiation and chemotherapy in addition to pathophysiology. This review aims to demonstrate the relationship between miRNAs and HNCs with a particular emphasis on how miRNAs impact HNCs signaling networks.

Quercetin modulates signal transductions and targets non-coding RNAs against cancer development

In recent decades, various investigations have indicated that natural compounds have great potential in the prevention and treatment of different chronic disorders including different types of cancer. As a bioactive flavonoid, Quercetin (Qu) is a dietary ingredient enjoying high pharmacological values and health-promoting effects due to its antioxidant and anti-inflammatory characterization. Conclusive in vitro and in vivo evidence has revealed that Qu has great potential in cancer prevention and development. Qu exerts its anticancer influences by altering various cellular processes such as apoptosis, autophagy, angiogenesis, metastasis, cell cycle, and proliferation. In this way, Qu by targeting numerous signaling pathways as well as non-coding RNAs regulates several cellular mechanisms to suppress cancer occurrence and promotion. This review aimed to summarize the impact of Qu on the molecular pathways and non-coding RNAs in modulating various cancer-associated cellular mechanisms.

Identification of natural products and FDA-approved drugs for targeting cancer stem cell (CSC) propagation

Here, we report the identification of key compounds that effectively inhibit the anchorage-independent growth and propagation of cancer stem cells (CSCs), as determined via screening using MCF7 cells, a human breast adenocarcinoma cell line. More specifically, we employed the mammosphere assay as an experimental format, which involves the generation of 3D spheroid cultures, using low-attachment plates. These positive hit compounds can be divided into 5 categories: 1) dietary supplements (quercetin and glucosamine); 2) FDA-approved drugs (carvedilol and ciprofloxacin); 3) natural products (aloe emodin, aloin, tannic acid, chlorophyllin copper salt, azelaic acid and adipic acid); 4) flavours (citral and limonene); and 5) vitamins (nicotinamide and nicotinic acid). In addition, for the compounds quercetin, glucosamine and carvedilol, we further assessed their metabolic action, using the Seahorse to conduct metabolic flux analysis. Our results indicate that these treatments can affect glycolytic flux and suppress oxidative mitochondrial metabolism (OXPHOS). Therefore, quercetin, glucosamine and carvedilol can reprogram the metabolic phenotype of breast cancer cells. Despite having diverse chemical structures, these compounds all interfere with mitochondrial metabolism. As these compounds halt CSCs propagation, ultimately, they may have therapeutic potential.

Contribution of Non-Coding RNAs to Anticancer Effects of Dietary Polyphenols: Chlorogenic Acid, Curcumin, Epigallocatechin-3-Gallate, Genistein, Quercetin and Resveratrol

Growing evidence has been accumulated to show the anticancer effects of daily consumption of polyphenols. These dietary polyphenols include chlorogenic acid, curcumin, epigallocatechin-3-O-gallate, genistein, quercetin, and resveratrol. These polyphenols have similar chemical and biological properties in that they can act as antioxidants and exert the anticancer effects via cell signaling pathways involving their reactive oxygen species (ROS)-scavenging activity. These polyphenols may also act as pro-oxidants under certain conditions, especially at high concentrations. Epigenetic modifications, including dysregulation of noncoding RNAs (ncRNAs) such as microRNAs, long noncoding RNAs, and circular RNAs are now known to be involved in the anticancer effects of polyphenols. These polyphenols can modulate the expression/activity of the component molecules in ROS-scavenger-triggered anticancer pathways (RSTAPs) by increasing the expression of tumor-suppressive ncRNAs and decreasing the expression of oncogenic ncRNAs in general. Multiple ncRNAs are similarly modulated by multiple polyphenols. Many of the targets of ncRNAs affected by these polyphenols are components of RSTAPs. Therefore, ncRNA modulation may enhance the anticancer effects of polyphenols via RSTAPs in an additive or synergistic manner, although other mechanisms may be operating as well.

Potential mechanisms of quercetin in cancer prevention: focus on cellular and molecular targets

Over the past few years, the cancer-related disease has had a high mortality rate and incidence worldwide, despite clinical advances in cancer treatment. The drugs used for cancer therapy, have high side effects in addition to the high cost. Subsequently, to reduce these side effects, many studies have suggested the use of natural bioactive compounds. Among these, which have recently attracted the attention of many researchers, quercetin has such properties. Quercetin, a plant flavonoid found in fresh fruits, vegetables and citrus fruits, has anti-cancer properties by inhibiting tumor proliferation, invasion, and tumor metastasis. Several studies have demonstrated the anti-cancer mechanism of quercetin, and these mechanisms are controlled through several signalling pathways within the cancer cell. Pathways involved in this process include apoptotic, p53, NF-κB, MAPK, JAK/STAT, PI3K/AKT, and Wnt/β-catenin pathways. In addition to regulating these pathways, quercetin controls the activity of oncogenic and tumor suppressor ncRNAs. Therefore, in this comprehensive review, we summarized the regulation of these signalling pathways by quercetin. The modulatory role of quercetin in the expression of various miRNAs has also been discussed. Understanding the basic anti-cancer mechanisms of these herbal compounds can help prevent and manage many types of cancer.

Research progress and clinical application prospects of miRNAs in oral cancer

Oral cancer is one of the most common malignant tumors worldwide, and it is also one of the most important and difficult clinical problems to be solved. Due to the regional differences in diet culture, some areas have taken the 'hardest hit' of oral cancer cases. However, the existing clinical treatment methods (surgery as the main treatment method, radiotherapy and chemotherapy as the auxiliary ones) do not have satisfactory treatment effects; therefore, new diagnosis and treatment methods need to be developed and utilized. Micro RNAs (miRNAs), as a class of substances that play an important regulatory role in the development of tumors, have an important value in the diagnosis and treatment of various tumors. At the same time, many miRNAs have obvious expression differences in oral cancer tissues compared to normal tissues. Therefore, they may have diagnostic and therapeutic effects on oral cancer. In this review, we evaluate the miRNAs that play a regulatory role in the development of oral cancer and those that are expected to be applied in the diagnosis and treatment of oral cancer. At the same time, we summarize the important challenges that need to be addressed, aiming to provide evidence and suggestions for the application of miRNAs in the diagnosis and treatment of oral cancer.

Anti-Cancer Effects of Dietary Polyphenols via ROS-Mediated Pathway with Their Modulation of MicroRNAs

Consumption of coffee, tea, wine, curry, and soybeans has been linked to a lower risk of cancer in epidemiological studies. Several cell-based and animal studies have shown that dietary polyphenols like chlorogenic acid, curcumin, epigallocatechin-3-O-gallate, genistein, quercetin and resveratrol play a major role in these anticancer effects. Several mechanisms have been proposed to explain the anticancer effects of polyphenols. Depending on the cellular microenvironment, these polyphenols can exert double-faced actions as either an antioxidant or a prooxidant, and one of the representative anticancer mechanisms is a reactive oxygen species (ROS)-mediated mechanism. These polyphenols can also influence microRNA (miR) expression. In general, they can modulate the expression/activity of the constituent molecules in ROS-mediated anticancer pathways by increasing the expression of tumor-suppressive miRs and decreasing the expression of oncogenic miRs. Thus, miR modulation may enhance the anticancer effects of polyphenols through the ROS-mediated pathways in an additive or synergistic manner. More precise human clinical studies on the effects of dietary polyphenols on miR expression will provide convincing evidence of the preventive roles of dietary polyphenols in cancer and other diseases.

The Targeting of Noncoding RNAs by Quercetin in Cancer Prevention and Therapy

The dietary flavonoid quercetin is ubiquitously distributed in fruits, vegetables, and medicinal herbs. Quercetin has been a focal point in recent years due to its versatile health-promoting benefits and high pharmacological values. It has well documented that quercetin exerts anticancer actions by inhibiting cell proliferation, inducing apoptosis, and retarding the invasion and metastasis of cancer cells. However, the exact mechanism of quercetin-mediated cancer chemoprevention is still not fully understood. With the advances in high-throughput sequencing technologies, the intricate oncogenic signaling networks have been gradually characterized. Increasing evidence on the close association between noncoding RNA (ncRNAs) and cancer etiopathogenesis emphasizes the potential of ncRNAs as promising molecular targets for cancer treatment. Available experimental studies indicate that quercetin can dominate multiple cancer-associated ncRNAs, hence repressing carcinogenesis and cancer development. Thus, modulation of ncRNAs serves as a key mechanism responsible for the anticancer effects of quercetin. In this review, we focus on the chemopreventive effects of quercetin on cancer pathogenesis by targeting cancer-relevant ncRNAs, supporting the viewpoint that quercetin holds promise as a drug candidate for cancer chemoprevention and chemotherapy. An in-depth comprehension of the interplay between quercetin and ncRNAs in the inhibition of cancer development and progression will raise the possibility of developing this bioactive compound as an anticancer agent that could be highly efficacious and safe in clinical practice.

Involvement of RUVBL1 in WNT/β-Catenin Signaling in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor of head and neck squamous cell carcinoma (HNSCC), but the causes and molecular mechanisms remain unclear. The wingless-integrated/β-catenin (WNT/β-catenin) signaling pathway plays a vital role in cancer cell proliferation, differentiation, and metastasis, including OSCC. To screen potential β-catenin-associated genes involved in OSCC, the intersection of these genes in the STRING and IMEx databases was assessed using differential expression genes (DEG) from public microarrays, and 22 were further selected to construct a β-catenin-protein interaction network. The top 14 hub genes (node degree > 10) within the network were selected. Pearson's correlation analysis showed that β-catenin expression correlated positively with the expression of 11 genes, including AR, BIRC5, CDK6, DKK1, GSK3B, MET, MITF, PARD3, RUVBL1, SLC9A3R1, and SMAD7. A heat map of overall hub gene survival was created, and elevated expression of DKK1 and RUVBL1 was associated with poor survival using the Mantel-Cox test. To identify the function of RUVBL1, colony formation assay, transwell assay, and western blotting revealed that knock-down of RUVBL1 by siRNA decreased H157 and Cal-27 cell proliferation and metastasis by inhibiting β-catenin signaling. These findings suggest that RUVBL1 may serve as a diagnostic and prognostic biomarker for OSCC, as well as a therapeutic target, and may help to uncover additional molecular mechanisms of β-catenin-driven OSCC tumorigenesis.

Cytotoxic and Antioxidant Effects of Phoenix dactylifera L. (Ajwa Date Extract) on Oral Squamous Cell Carcinoma Cell Line

Aim

The aim of the current study is to investigate the antioxidant and apoptotic potential of Ajwa date flesh (ADF) and Ajwa date pit (ADP) extract on human squamous cell carcinoma cell line (HSC-2).

Method

ADF and ADP were extracted with a solvent extraction method using hexane, acetone, and ethanol, which were then subjected to antioxidant assay by 2,2-diphenyl-1-picrylhydrazyl (DPPH). HSC-2 cells were then treated with different concentrations of ADF and ADP extract for 24, 48, and 72 hours. MTT assay was performed to assess the antiproliferative effect, and Annexin V-FITC was used for the detection of cellular apoptosis.

Results

Acetone extracts of ADF and ADP had the highest radical scavenging and antioxidant activities followed by the ethanolic extracts, whereas ADP appeared to have significantly higher antioxidant effects than ADF. MTT assay demonstrated that acetone extracts of ADF and ADP were significantly cytotoxic against HSC-2 cells in a dose- and time-dependent manner. The half inhibitory concentration (IC50) of ADF was found to be 8.69 mg/ml at 24 h, and the maximum cell growth inhibition was observed at 50 mg/ml. The IC50 for the ADP was found to be 0.97 mg/ml at 24 h, and the maximum cell growth inhibition was observed at 5 mg/ml. Statistical analysis of the flow cytometry assay showed that the treatment with ADF and ADP extracts had a significant apoptotic effect which occurred in a dose-dependent manner. HSC-2 cells were seen in the late apoptotic stage with higher doses of ADF and ADP extract. ADP extract demonstrated higher apoptotic activity than ADF extract. In addition, combined treatment of ADF and ADP was also performed on HSC-2 cells which demonstrated higher apoptotic activity when compared to the single extract.

Conclusion

Ajwa date fruit has a promising cytotoxic effect by inhibiting the growth and proliferation of OSCC cells and inducing cell death by apoptosis.

The role of polyphenols in overcoming cancer drug resistance: a comprehensive review

Chemotherapeutic drugs are used to treat advanced stages of cancer or following surgery. However, cancers often develop resistance against drugs, leading to failure of treatment and recurrence of the disease. Polyphenols are a family of organic compounds with more than 10,000 members which have a three-membered flavan ring system in common. These natural compounds are known for their beneficial properties, such as free radical scavenging, decreasing oxidative stress, and modulating inflammation. Herein, we discuss the role of polyphenols (mainly curcumin, resveratrol, and epigallocatechin gallate [EGCG]) in different aspects of cancer drug resistance. Increasing drug uptake by tumor cells, decreasing drug metabolism by enzymes (e.g. cytochromes and glutathione-S-transferases), and reducing drug efflux are some of the mechanisms by which polyphenols increase the sensitivity of cancer cells to chemotherapeutic agents. Polyphenols also affect other targets for overcoming chemoresistance in cancer cells, including cell death (i.e. autophagy and apoptosis), EMT, ROS, DNA repair processes, cancer stem cells, and epigenetics (e.g. miRNAs).

Role of Flavonoids as Epigenetic Modulators in Cancer Prevention and Therapy

Epigenetic regulation involves reversible changes in histones and DNA modifications that can be inherited without any changes in the DNA sequence. Dysregulation of normal epigenetic processes can lead to aberrant gene expression as observed in many diseases, notably cancer. Recent insights into the mechanisms of DNA methylation, histone modifications, and non-coding RNAs involved in altered gene expression profiles of tumor cells have caused a paradigm shift in the diagnostic and therapeutic approaches towards cancer. There has been a surge in search for compounds that could modulate the altered epigenetic landscape of tumor cells, and to exploit their therapeutic potential against cancers. Flavonoids are naturally occurring phenol compounds which are abundantly found among phytochemicals and have potentials to modulate epigenetic processes. Knowledge of the precise flavonoid-mediated epigenetic alterations is needed for the development of epigenetics drugs and combinatorial therapeutic approaches against cancers. This review is aimed to comprehensively explore the epigenetic modulations of flavonoids and their anti-tumor activities.

N6-methyladenosine reader YTH N6-methyladenosine RNA binding protein 3 or insulin like growth factor 2 mRNA binding protein 2 knockdown protects human bronchial epithelial cells from hypoxia/reoxygenation injury by inactivating p38 MAPK, AKT, ERK1/2, and NF-κB pathways

Lung ischemia/reperfusion (I/R) injury (LIRI) is a common complication after lung transplantation, embolism, and trauma. N6-methyladenosine (m6A) methylation modification is implicated in the pathogenesis of I/R injury. However, there are no or few reports of m6A-related regulators in LIRI till now. In this text, dysregulated genes in lung tissues of LIRI rats versus the sham group were identified by RNA sequencing (RNA-seq). RNA-seq outcomes revealed that only YTH N6-methyladenosine RNA binding protein 3 (YTHDF3) and insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) were differentially expressed in the LIRI versus sham group among 20 m6A-related regulators. Next, the functions and molecular mechanisms of YTHDF3 and IGF2BP2 in LIRI were investigated in a hypoxia/reoxygenation-induced BEAS-2B cell injury model in vitro. Results showed that YTHDF3 or IGF2BP2 knockdown attenuated hypoxia/reoxygenation-mediated inhibitory effects on cell survival and cell cycle progression and inhibited hypoxia/reoxygenation-induced cell apoptosis and pro-inflammatory cytokine secretion in BEAS-2B cells. Genes that could be directly regulated by YTHDF3 or IGF2BP2 were identified based on prior experimental data and bioinformatics analysis. Moreover, multiple potential downstream pathways of YTHDF3 and IGF2BP2 were identified by the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analysis of the above-mentioned genes. Among these potential pathways, we demonstrated that YTHDF3 or IGF2BP2 knockdown inhibited hypoxia/reoxygenation-activated p38, ERK1/2, AKT, and NF-κB pathways in BEAS-2B cells. In conclusion, YTHDF3 or IGF2BP2 knockdown weakened hypoxia/reoxygenation-induced human lung bronchial epithelial cell injury by inactivating p38, AKT, ERK1/2, and NF-κB pathways.

Quercetin Antagonizes Esophagus Cancer by Modulating miR-1-3p/TAGLN2 Pathway-Dependent Growth and Metastasis

The progression of esophagus cancer (EC) is associated with the alterative expressions of multiple microRNAs (miRs). MiR-1-3p is reported to inhibit the development of EC by targeting TAGLN2. Quercetin (Que) is a natural compound capable of antagonizing esophagus carcinoma (EC). In the current study, the role of miR-1-3p/TAGLN2 axis in the anti-EC function of Que was explored. Human EC cell lines KYSE-510 and TE-7 were treated with Que. Then the effects of Que on the growth and metastasis of EC cells, and on the activity of miR-1-3p/TAGLN2 axis were detected. The interaction between Que and miR-1-3p axis was further assessed by inhibiting miR-1-3p level in EC cells. The results showed that the treatment of Que impaired the growth and induced cell apoptosis in EC cells. The invasive ability of EC cells was also suppressed by Que. At molecular level, the expression of miR-1-3p was induced, while the expression of TAGLN2 was suppressed by Que. Moreover, the anti-EC effects of Que were blocked by miR-1-3p inhibition, which was represented by the restored growth and invasion of EC cells. Collectively, the current study demonstrated that Que exerted inhibitory effects on EC cells by inducing miR-1-3p.Supplemental data for this article is available online at https://doi.org/10.1080/01635581.2021.1972125.

MiR-148a-3p Regulates the Invasion and Odontoblastic Differentiation of Human Dental Pulp Stem Cells via the Wnt1/β-Catenin Pathway

Background and Objectives

MiR-148a-3p has been reported to regulate the differentiation of marrow stromal cell osteoblast. In this study, whether miR-148a-3p regulated the odontoblastic differentiation of human dental pulp stem cells (hDPSCs) or not was explored.

Methods and Results

The hDPSCs were isolated and identified via flow cytometry. Targets of miR-148a-3p were identified via bioinformatics and dual-luciferase reporter assay. After the cell was cultured in the odontogenic differentiation medium or infected, cell viability, invasion, and odontoblastic differentiation were detected via MTT, transwell, and Alizarin Red S staining, respectively. The miR-148a-3p, Wnt1, β-catenin, DSPP, DMP-1, RUNX2, OCN, and Smad4 expressions were determined by RT-qPCR and Western blot. The hDPSCs odontoblastic differentiation downregulated the miR-148a-3p expression and upregulated Wnt1 expression. Wnt1 was determined as the target for miR-148a-3p. MiR-148a-3p mimic and siWnt1 suppressed the cell viability, invasion, and odontoblastic differentiation of hDPSCs and inhibited the Wnt1, β-catenin, DSPP, DMP-1, RUNX2, OCN, and Smad4 expressions. In contrast, miR-148a-3p inhibitor and overexpressed Wnt1 promoted the cell viability, invasion, and odontoblastic differentiation of hDPSCs, and upregulated the Wnt1, β-catenin, DSPP, DMP-1, RUNX2, OCN, and Smad4 expressions. Also, miR-148a-3p mimic and inhibitor reversed the effects of Wnt1 overexpression and siWnt1.

Conclusions

MiR-148a-3p modulated the invasion and odontoblastic differentiation of hDPSCs through the Wnt1/β-catenin pathway.

Phytochemicals as Potential Chemopreventive and Chemotherapeutic Agents for Emerging Human Papillomavirus-Driven Head and Neck Cancer: Current Evidence and Future Prospects

Head and neck cancer (HNC) usually arises from squamous cells of the upper aerodigestive tract that line the mucosal surface in the head and neck region. In India, HNC is common in males, and it is the sixth most common cancer globally. Conventionally, HNC attributes to the use of alcohol or chewing tobacco. Over the past four decades, portions of human papillomavirus (HPV)-positive HNC are increasing at an alarming rate. Identification based on the etiological factors and molecular signatures demonstrates that these neoplastic lesions belong to a distinct category that differs in pathological characteristics and therapeutic response. Slow development in HNC therapeutics has resulted in a low 5-year survival rate in the last two decades. Interestingly, HPV-positive HNC has shown better outcomes following conservative treatments and immunotherapies. This raises demand to have a pre-therapy assessment of HPV status to decide the treatment strategy. Moreover, there is no HPV-specific treatment for HPV-positive HNC patients. Accumulating evidence suggests that phytochemicals are promising leads against HNC and show potential as adjuvants to chemoradiotherapy in HNC. However, only a few of these phytochemicals target HPV. The aim of the present article was to collate data on various leading phytochemicals that have shown promising results in the prevention and treatment of HNC in general and HPV-driven HNC. The review explores the possibility of using these leads against HPV-positive tumors as some of the signaling pathways are common. The review also addresses various challenges in the field that prevent their use in clinical settings.

Calunduloside E inhibits HepG2 cell proliferation and migration via p38/JNK-HMGB1 signalling axis

High-mobility group box 1 (HMGB1), a highly conserved chromosome protein, is considered as a potential therapeutic target and novel biomarker because of its regulation in the proliferation and metastasis of Hepatocellular carcinoma (HCC). Calenduloside E (CE), a natural active product, has been reported to anti-cancer effect. However, the role and underlying molecular mechanism of CE in HCC is still unclear. The purpose of this study is to investigate the effects of CE on the proliferation and migration of HCC, and then explore the possible underlying molecular mechanism. HepG2 cells were treated with CE or transfected with HMGB1 shRNA plasmids, EdU and colony formation assays were used to detect cell proliferation ability. Wound healing and transwell assays were used to determine the role of CE in cell migration. The expression of Cyclins, PCNA, MMPs, HMGB1, N-cadherin, E-cadherin and phosphorylation of p38, ERK and JNK were all detected using Western blotting. Our results showed that CE inhibited HepG2 cells proliferation and migration in a dose dependent manner; reduced the expression levels of Cycins, PCNA, HMGB1, MMPs and N-cadherin; up-regulated E-cadherin expression; enhanced the phosphorylation of p38 and JNK signalling pathways. Blocking the activation of p38 and JNK obviously reversed CE-mediated inhibitory effects on HepG2 cell proliferation and migration; reversed CE-induced down-regulation of Cyclins, PCNA, MMPs, N-cadherin and HMGB1, as well as E-cadherin up-regulation. In conclusion, our study suggested that CE reduces the expression levels of Cyclins, MMPs and epithelial-mesenchymal transformation (EMT) through p38/JNK-HMGB1 signaling axis and then inhibits HepG2 cells proliferation and migration in HepG2 cells. This study provides a new perspective for the anti-tumour molecular mechanism of CE in HCC.

MicroRNA-22 in female malignancies: Focusing on breast, cervical, and ovarian cancers

MicroRNAs (miRNAs), a novelty-defined class of regulatory genes, have revolutionized principles of classical bimolecular. These RNAs regulate the expression of a gene through inhibition of translational initiation or targeting mRNAs for degradation. MiRNAs act in several biological operations, including proliferation, differentiation, and cell death, and their expression is often abnormal in human diseases such as cancer. In recent years, miR-22 has attracted much attention from researchers. Its expression is downregulated in female malignancies such as breast, cervical, and ovarian cancers, exhibiting that miR-22 plays a tumor-suppressive function in these cancers. Also, different reports exist about the involvement of miR-22 in non-tumor diseases. In the present review, we report the results of performed studies on the potential roles of miR-22 in female malignancies with a focus on breast, cervical, and ovarian cancers. Also, we summary its predicted target genes in various cancers. In conclusion, it is effective for researchers to understand the role of miR-22 in different cellular operations.

Roles of microRNAs in Regulating Cancer Stemness in Head and Neck Cancers

Head and neck squamous cell carcinomas (HNSCCs) are epithelial malignancies with 5-year overall survival rates of approximately 40-50%. Emerging evidence indicates that a small population of cells in HNSCC patients, named cancer stem cells (CSCs), play vital roles in the processes of tumor initiation, progression, metastasis, immune evasion, chemo-/radioresistance, and recurrence. The acquisition of stem-like properties of cancer cells further provides cellular plasticity for stress adaptation and contributes to therapeutic resistance, resulting in a worse clinical outcome. Thus, targeting cancer stemness is fundamental for cancer treatment. MicroRNAs (miRNAs) are known to regulate stem cell features in the development and tissue regeneration through a miRNA-target interactive network. In HNSCCs, miRNAs act as tumor suppressors and/or oncogenes to modulate cancer stemness and therapeutic efficacy by regulating the CSC-specific tumor microenvironment (TME) and signaling pathways, such as epithelial-to-mesenchymal transition (EMT), Wnt/β-catenin signaling, and epidermal growth factor receptor (EGFR) or insulin-like growth factor 1 receptor (IGF1R) signaling pathways. Owing to a deeper understanding of disease-relevant miRNAs and advances in in vivo delivery systems, the administration of miRNA-based therapeutics is feasible and safe in humans, with encouraging efficacy results in early-phase clinical trials. In this review, we summarize the present findings to better understand the mechanical actions of miRNAs in maintaining CSCs and acquiring the stem-like features of cancer cells during HNSCC pathogenesis.

Dietary polyphenols suppress chronic inflammation by modulation of multiple inflammation-associated cell signaling pathways

The high failure rate of the reductionist approach to discover effective and safe drugs to treat chronic inflammatory diseases has led scientists to seek alternative ways. Recently, targeting cell signaling pathways has been utilized as an innovative approach to discover drug leads from natural products. Cell signaling mechanisms have been identified playing key role in diverse diseases by inducing proliferation, cell survival and apoptosis. Phytochemicals are known to be able to modulate the cellular and molecular networks which are associated to chronic diseases including cancer-associated inflammation. In this review, the roles of dietary polyphenols (apigenin, kaempferol, quercetin, curcumin, genistein, isoliquiritigenin, resveratrol and gallic acid) in modulating multiple inflammation-associated cell signaling networks are deliberated. Scientific databases on suppressive effects of the polyphenols on chronic inflammation via modulation of the pathways especially in the recent five years are gathered and critically analyzed. The polyphenols are able to modulate several inflammation-associated cell signaling pathways, namely nuclear factor-kappa β, mitogen activated protein kinases, Wnt/β-catenin and phosphatidylinositol 3-kinase and protein kinase B via selective actions on various components of the networks. The suppressive effects of the polyphenols on the multiple cell signaling pathways reveal their potential use in prevention and treatment of chronic inflammatory disorders. Understanding the mechanistic effects involved in modulation of the signaling pathways by the polyphenols is necessary for lead identification and development of future functional foods for prevention and treatment of chronic inflammatory diseases.

Comprehending the crosstalk between Notch, Wnt and Hedgehog signaling pathways in oral squamous cell carcinoma - clinical implications

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a malignant oral cavity neoplasm that affects many people, especially in developing countries. Despite several advances that have been made in diagnosis and treatment, the morbidity and mortality rates due to OSCC remain high. Accumulating evidence indicates that aberrant activation of cellular signaling pathways, such as the Notch, Wnt and Hedgehog pathways, occurs during the development and metastasis of OSCC. In this review, we have articulated the roles of the Notch, Wnt and Hedgehog signaling pathways in OSCC and their crosstalk during tumor development and progression. We have also examined possible interactions and associations between these pathways and treatment regimens that could be employed to effectively tackle OSCC and/or prevent its recurrence.

CONCLUSIONS

Activation of the Notch signaling pathway upregulates the expression of several genes, including c-Myc, β-catenin, NF-κB and Shh. Associations between the Notch signaling pathway and other pathways have been shown to enhance OSCC tumor aggressiveness. Crosstalk between these pathways supports the maintenance of cancer stem cells (CSCs) and regulates OSCC cell motility. Thus, application of compounds that block these pathways may be a valid strategy to treat OSCC. Such compounds have already been employed in other types of cancer and could be repurposed for OSCC.

Quercetin suppresses cell survival and invasion in oral squamous cell carcinoma via the miR-1254/CD36 cascade in vitro

OBJECTIVE

This study aimed to investigate the effects of quercetin on the proliferation and invasion in oral squamous cell carcinoma (OSCC) and examine its effect on the activation of the miR-1254/CD36 signaling pathway.

METHODS

Proliferation and invasion experiments were performed in the OSCC cell line CAL-27 in which miR-1254 was overexpressed or inhibited. The levels of miR-1254 and CD36 were determined using quantitative real-time polymerase chain reaction and Western blotting assays.

RESULTS

Quercetin significantly suppressed the proliferation and invasion of CAL-27 cells in a dose-dependent manner, while up-regulating miR-1254 and down-regulating CD36. The overexpression of miR-1254 also considerably down-regulated CD36 and enhanced the ability of quercetin to inhibit CAL-27 cell survival and invasion. Conversely, the inhibition of miR-1254 significantly up-regulated CD36 and antagonized the inhibitory effects of quercetin.

CONCLUSION

Our study suggests that quercetin might suppress the progression of OSCC by activating the miR-1254/CD36 signaling pathway, indicating its potential as a treatment against OSCC.

Anticancer Potential of Selected Flavonols: Fisetin, Kaempferol, and Quercetin on Head and Neck Cancers

Flavonols are ones of the most common phytochemicals found in diets rich in fruit and vegetables. Research suggests that molecular functions of flavonoids may bring a number of health benefits to people, including the following: decrease inflammation, change disease activity, and alleviate resistance to antibiotics as well as chemotherapeutics. Their antiproliferative, antioxidant, anti-inflammatory, and antineoplastic activity has been proved. They may act as antioxidants, while preventing DNA damage by scavenging reactive oxygen radicals, reinforcing DNA repair, disrupting chemical damages by induction of phase II enzymes, and modifying signal transduction pathways. One of such research areas is a potential effect of flavonoids on the risk of developing cancer. The aim of our paper is to present a systematic review of antineoplastic activity of flavonols in general. Special attention was paid to selected flavonols: fisetin, kaempferol, and quercetin in preclinical and in vitro studies. Study results prove antiproliferative and proapoptotic properties of flavonols with regard to head and neck cancer. However, few study papers evaluate specific activities during various processes associated with cancer progression. Moreover, an attempt was made to collect the majority of substantive studies on bioactive potential of the selected flavonols, especially with regard to modulation of a range of signal transduction pathways that participate in cancer development.

Thymoquinone loaded calcium alginate and polyvinyl alcohol carrier inhibits the 7,12-dimethylbenz[a]anthracene-induced hamster oral cancer via the down-regulation of PI3K/AKT/mTOR signaling pathways

Oral cancer is a multifactorial cancer that affects millions of peoples worldwide. The current exploration aimed to evaluate the mechanisms that thymoquinone nanoencapsulated carrier and its effects on 7,12-Dimethylbenz[a]anthracene (DMBA) stimulated hamster buccal pouch cancer in Syrian hamster model. Nanocarrier was characterized by SEM, TEM, FTIR analysis. The incidence of tumor, and biochemicals makers was studied through standard methods. The mRNA expression level of inflammatory markers NF-κBp50, NF-κBp65, and PI3K/AKT/mTOR markers in the buccal tissues of control and experimental animals were investigated through RT-PCR analysis. In thymoquinone (TQ) loaded calcium alginate and polyvinyl alcohol carrier (TQ/Ca-alg-PVA) no squamous cell carcinogenesis developed and others moderate dysplasia revealed differentiated form of hyperplasia and keratosis. In biochemical analyses with DMBA + TQ/Ca-alg-PVA (20 mg/kg bw) orally administered hamsters showed restored the antioxidants, detoxification, xenobiotic metabolising enzymes in DMBA induced plasma and oral tissues of hamsters. Further, mRNA expression level of NF-κBp50/p65 and PI3K/AKT/mTOR were upregulated in the DMBA alone painted hamster. In contrast, these expressions were down regulated in orally TQ/Ca-alg-PVA treated experimental animals. This ability more eligible to deregulate the inflammatory and PI3K/AKT/mTOR signaling pathway that proved it suppresses anti-invasion/metastasis activity during hamster buccal pouch carcinogenesis. From this study, we recommended that TQ/Ca-alg-PVA has documented as effective chemopreventive agents, in further many molecular machineries need to study.

The use of propolis in dentistry, oral health, and medicine: A review

BACKGROUND

Propolis is a resinous product that is collected from plants by bees to cover holes and crevices in their hives. Propolis has potent antibacterial, antiviral, anti-inflammatory, wound healing, and anticancer properties. Propolis has been used therapeutically by humans for centuries, including the treatment of dental caries and mouth infections.

HIGHLIGHT

This review article attempts to analyze the potential use of propolis in general dentistry and oral health management.

CONCLUSION

Propolis is potentially useful in dentistry and oral health management based on available in vitro, in vivo, and ex vivo studies, as well as human clinical trials.

Roles of the Wnt Signaling Pathway in Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the most common type of head and neck tumor. It is a high incidence malignant tumor associated with a low survival rate and limited treatment options. Accumulating conclusions indicate that the Wnt signaling pathway plays a vital role in the pathobiological process of HNSCC. The canonical Wnt/β-catenin signaling pathway affects a variety of cellular progression, enabling tumor cells to maintain and further promote the immature stem-like phenotype, proliferate, prolong survival, and gain invasiveness. Genomic studies of head and neck tumors have shown that although β-catenin is not frequently mutated in HNSCC, its activity is not inhibited by mutations in upstream gene encoding β-catenin, NOTCH1, FAT1, and AJUBA. Genetic defects affect the components of the Wnt pathway in oral squamous cell carcinoma (OSCC) and the epigenetic mechanisms that regulate inhibitors of the Wnt pathway. This paper aims to summarize the groundbreaking discoveries and recent advances involving the Wnt signaling pathway and highlight the relevance of this pathway in head and neck squamous cell cancer, which will help provide new insights into improving the treatment of human HNSCC by interfering with the transcriptional signaling of Wnt.