Icaritin Reduces Oral Squamous Cell Carcinoma Progression via the Inhibition of STAT3 Signaling

Advances in Pharmacological Research on Icaritin: A Comprehensive Review

Epimedium has been widely used in traditional Chinese medicine for several thousands of years. This plant is known for tonifying kidney Yang, strengthening muscles and bones, and dispelling wind and dampness. It is worth noting that icaritin, a prenylated flavonoid isolated from Epimedium, has received increasing attention in recent years due to its wide range of pharmacological activities. Icaritin exhibits significant therapeutic potential against various diseases, such as osteoporosis, tumors (hepatocellular carcinoma, stomach cancer, breast cancer, and glioblastoma), cerebral ischemia skin injury, thrombocytopenia, and systemic lupus erythematosus. We review the pharmacological activities of icaritin and its potential molecular mechanisms for the treatment of related diseases. The data suggest that icaritin can have the pharmacological effects of mediating Wnt/[Formula: see text]-catenin, IL-6/JAK2/STAT3, AMPK/mTOR, PTEN/AKT, MAPK, NF-[Formula: see text]B, and other signaling pathways. This paper also discusses the progress of clinical trials of icaritin. Icaritin was approved by the State Food and Drug Administration in January 2022 for the treatment of advanced HCC, and has various clinical drug prospects. Although it has some disadvantages, including poor solubility, and low bioavailability, icaritin is still a prospective candidate for the development of naturally derived drugs, especially in the treatment of tumors and inflammatory diseases. This review aims to update and deepen the understanding of icaritin, and provide a theoretical basis for its further study.

Icariin mediates autophagy and apoptosis of hepatocellular carcinoma cells induced by the β-catenin signaling pathway through lncRNA LOXL1-AS1

To investigate the effect of icariin (ICA) on hepatocellular carcinoma (HCC) and its autophagy/apoptosis mechanism in HCC. The anti-HCC mechanism of ICA was investigated using HCC cells treated with 20 µmol/L ICA. Cell viability and proliferation were assessed using CCK-8 and colony formation assays, respectively, while TUNEL staining evaluated anti-apoptotic effects. DHE staining quantified intracellular ROS levels, and JC-1 staining assessed mitochondrial membrane potential. The expression of LC3 was detected by immunofluorescence staining. Additionally, HepG2 cells (2.0 × 106) were implanted into the thymus of BALB/c nude mice, which received intraperitoneal injections of 40 mg/kg ICA. Western blotting was used to evaluate the expression of proteins related to apoptosis and autophagy. ICA effectively inhibited the proliferation and invasion of HCC cells, enhancing autophagy and apoptosis. Silencing of lncRNA LOXL1-AS1 reduced β-catenin expression and downregulated PI3K/AKT/mTOR pathway phosphorylation. Targeting β-catenin with siRNA augmented apoptosis in HepG2 cells through elevated levels of Bax and caspase-3/8/9 and boosted autophagy via increased expression of LC3-II, Atg5, Atg7, Atg8, and Beclin-1. ICA reversed this autophagic effect, while rapamycin enhanced ICA's efficacy. In vivo, ICA suppressed tumor growth and promoted autophagy and apoptosis in mice. Icariin induces autophagy and apoptosis in HCC cells via the β-catenin signaling pathway mediated by lncRNA LOXL1-AS1, offering a novel approach to HCC clinical management.

New insights into the anticancer therapeutic potential of icaritin and its synthetic derivatives

Icaritin is a natural prenylated flavonoid derived from the Chinese herb Epimedium. The compound has shown antitumor effects in various cancers, especially hepatocellular carcinoma (HCC). Icaritin exerts its anticancer activity by modulating multiple signaling pathways, such as IL-6/JAK/STAT3, ER-α36, and NF-κB, affecting the tumor microenvironment and immune system. Several clinical trials have evaluated the safety and efficacy of icaritin in advanced HCC patients with poor prognoses, who are unsuitable for conventional therapies. The results have demonstrated that icaritin can improve survival, delay progression, and produce clinical benefits in these patients, with a favorable safety profile and minimal adverse events. Moreover, icaritin can enhance the antitumor immune response by regulating the function and phenotype of various immune cells, such as CD8+ T cells, MDSCs, neutrophils, and macrophages. These findings suggest that icaritin is a promising candidate for immunotherapy in HCC and other cancers. However, further studies are needed to elucidate the molecular mechanisms and optimal dosing regimens of icaritin and its potential synergistic effects with other agents. Therefore, this comprehensive review of the scientific literature aims to summarize advances in the knowledge of icaritin in preclinical and clinical studies as well as the pharmacokinetic, metabolism, toxicity, and mechanisms action to recognize the main challenge, gaps, and opportunities to develop a medication that cancer patients can use. Thus, our main objective was to clarify the current state of icaritin for use as an anticancer drug.

Flavonoids as promising anticancer therapeutics: Contemporary research, nanoantioxidant potential, and future scope

Flavonoids are natural polyphenolic compounds considered safe, pleiotropic, and readily available molecules. It is widely distributed in various food products such as fruits and vegetables and beverages such as green tea, wine, and coca-based products. Many studies have reported the anticancer potential of flavonoids against different types of cancers, including solid tumors. The chemopreventive effect of flavonoids is attributed to various mechanisms, including modulation of autophagy, induction of cell cycle arrest, apoptosis, and antioxidant defense. Despite of significant anticancer activity of flavonoids, their clinical translation is limited due to their poor biopharmaceutical attributes (such as low aqueous solubility, limited permeability across the biological membranes (intestinal and blood-brain barrier), and stability issue in biological systems). A nanoparticulate system is an approach that is widely utilized to improve the biopharmaceutical performance and therapeutic efficacy of phytopharmaceuticals. The present review discusses the significant anticancer potential of promising flavonoids in different cancers and the utilization of nanoparticulate systems to improve their nanoantioxidant activity further to enhance the anticancer activity of loaded promising flavonoids. Although, various plant-derived secondary metabolites including flavonoids have been recommended for treating cancer, further vigilant research is warranted to prove their translational values.

Advancements in the Biotransformation and Biosynthesis of the Primary Active Flavonoids Derived from Epimedium

Epimedium is a classical Chinese herbal medicine, which has been used extensively to treat various diseases, such as sexual dysfunction, osteoporosis, cancer, rheumatoid arthritis, and brain diseases. Flavonoids, such as icariin, baohuoside I, icaritin, and epimedin C, are the main active ingredients with diverse pharmacological activities. Currently, most Epimedium flavonoids are extracted from Epimedium plants, but this method cannot meet the increasing market demand. Biotransformation strategies promised huge potential for increasing the contents of high-value Epimedium flavonoids, which would promote the full use of the Epimedium herb. Complete biosynthesis of major Epimedium flavonoids by microbial cell factories would enable industrial-scale production of Epimedium flavonoids. This review summarizes the structures, pharmacological activities, and biosynthesis pathways in the Epimedium plant, as well as the extraction methods of major Epimedium flavonoids, and advancements in the biotransformation and complete microbial synthesis of Epimedium flavonoids, which would provide valuable insights for future studies on Epimedium herb usage and the production of Epimedium flavonoids.

Icaritin ameliorates RANKL-mediated osteoclastogenesis and ovariectomy-induced osteoporosis

A rapidly aging society and longer life expectancy are causing osteoporosis to become a global epidemic. Over the last five decades, a number of drugs aimed at reducing bone resorption or restoring bone mass have been developed, but their efficacy and safety are limited. Icaritin (ICT) is a natural compound extracted from anti-osteoporosis herb Epimedium spp. and has been shown to inhibit osteoclast differentiation. However, the molecular mechanism by which ICT weaken RANKL-induced osteoclast differentiation has not been completely investigated. Here, we evaluated the anti-osteoclastogenic effect of ICT in vitro and the potential drug candidate for treating osteoporosis in vivo. In vitro study, ICT was found to inhibit osteoclast formation and bone resorption function via downregulating transcription factors activated T cell cytoplasm 1 (NFATc1) and c-fos, which further downregulate osteoclastogenesis-specific gene. In addition, the enhanced mitochondrial mass and function required for osteoclast differentiation was mitigated by ICT. The histomorphological results from an in vivo study showed that ICT attenuated the bone loss associated with ovariectomy (OVX). Based on these results, we propose ICT as a promising new drug strategy for osteoporosis that inhibits osteoclast differentiation.

Icaritin: A phytomolecule with enormous pharmacological values

Pharmacological studies on flavonoids have always drawn much interest for many years. Icaritin (ICT), a representative flavone containing an 8-prenyl group, is a principal compound detected in medicinal plants of the genus Epimedum, the family Berberidaceae. Experimental results in the phytochemistry and pharmacology of this molecule are abundant now, but a deep overview has not been carried out. The goal of this review is to provide an insight into the natural observation, biosynthesis, biotransformation, synthesis, pharmacology, and pharmacokinetics of prenyl flavone ICT. The relevant data on ICT was collected from bibliographic sources, like Google Scholar, Web of Science, Sci-Finder, and various published journals. "Icaritin" alone or in combination is the main keyword to seek for references, and references have been updated till now. ICT is among the characteristic phytomolecules of Epimedum plants. Bacteria monitored its biosynthesis and biotransformation, while this agent was rapidly synthesized from phloroglucinol by microwave-assistance Claisen rearrangement. ICT is a potential agent in numerous in vitro and in vivo pharmacological records, which demonstrated its role in cancer treatments via apoptotic-related mechanisms. It also brings in various health benefits since it reduced harmful effects on the liver, lung, heart, bone, blood, and skin, and improved immune responses. Pharmacokinetic outcomes indicated that its metabolic pathway involved hydration, hydroxylation, dehydrogenation, glycosylation, and glucuronidation. Molecule mechanisms of action at a cellular level are predominant, but clinical studies are expected to get more. Structure-activity relationship records seem insufficient, and the studies on nano-combined approaches to improve its soluble property in living bodied medium are needed.

Exosome-mediated long noncoding RNA (lncRNA) PART1 suppresses malignant progression of oral squamous cell carcinoma via miR-17-5p/SOCS6 axis

BACKGROUND

Exosomes derived from oral squamous cell carcinoma (OSCC) could modulate OSCC development. This study aimed to explore effects of exosome-mediated lncRNA PART1 on OSCC cells.

METHODS

This study was performed in Tianjin Medical University Cancer Institute from February 2021 to March 2022. Bioinformatic analysis was performed on the public database GEPIA (http://gepia.cancer-pku.cn/). Exosomes isolated from cell lines squamous cell carcinoma 9 (SCC9) and Centre Antoine Lacassagne-27 (CAL27) were identified by transmission electron microscope and western blot. Exosome-mediated lncRNA PART1, microRNA-17-5p(miR-17-5p) and suppressor of cytokine signaling 6(SOCS6) RNA expressions were assessed by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Cell counting kit8(CCK-8), caspase-3 activity, and flow cytometry were applied to evaluate OSCC cell viabilities and apoptosis. Meanwhile, OSCC cell migratory ability and invasiveness were evaluated using transwell assay. Bindings between miR-17-5p and lncRNA PART1 or SOCS6 were validated using the luciferase reporter test. Western blot was used for detecting the protein levels of SOCS6, phosphorylated signal transducer and activator of transcription 3 (STAT3) and STAT3.

RESULTS

: According to GEPIA, lncRNA PART1 was downregulated in OSCC tissue samples and cells, and it had a positive correlation with the good prognosis of Head and neck squamous cell cancer (HNSCC) patients. After the exosomes from OSCC cells were isolated and verified, PART1 was then confirmed to be secreted by exosomes. Further, overexpression of exosome-mediated lncRNA PART1 inhibited OSCC cell viabilities, migration, and invasiveness but facilitated OSCC cell apoptosis. PART1 upregulated SOCS6 through sponging miR-17-5p. Moreover, exosome-mediated lncRNA PART1 suppressed the phosphorylation of STAT3.

DISCUSSION

Exosome-mediated lncRNA PART1 could mediate the OSCC progression via miR-17-5p/SOCS6 axis in vitro, suggesting that lncRNA PART1 might be a target for treating OSCC.

SCARA5 inhibits oral squamous cell carcinoma via inactivating the STAT3 and PI3K/AKT signaling pathways

Oral squamous cell carcinoma (OSCC) is a common tumor in the world. Despite the rapid development of medical care, OSCC is also accompanied by high incidence and mortality every year. Therefore, it is still necessary to continuously develop new methods or find new targets to treat OSCC. Previous research showed that scavenger receptor class A member 5 (SCARA5) was one of the potential biomarkers of OSCC, and its expression is significantly low in OSCC. This study aimed to explore the role and related molecular mechanisms of SCARA5 in OSCC. In this study, we found that the SCARA5 expression was lower in CAL-27 and SCC-9 cells than that in human normal oral epithelial keratinocytes. SCARA5 overexpression significantly inhibited cell proliferation and induced apoptosis of CAL-27 and SCC-9 cells. In addition, SCARA5 repressed OSCC cell epithelial-mesenchymal transformation (EMT), evidenced by increased E-cadherin expression and reduced N-cadherin expression. Finally, we found that SCARA5 could suppress STAT3, PI3K, and AKT phosphorylation. Therefore, SCARA5 was related to STAT3 and PI3K/AKT signaling pathways in OSCC. In conclusion, SCARA5 inhibited the proliferation and EMT and induced the apoptosis of OSCC cells through the inhibition of STAT3 and PI3K/AKT signaling pathways, thereby exerting a tumor suppressor effect.

Exploring the pharmacological mechanisms of icaritin against nasopharyngeal carcinoma via network pharmacology and experimental validation

Background: Icaritin is a natural product with a wide range of anti-tumor effects. However, its anti-tumor mechanism has not been thoroughly studied. This study examined the inhibitory effect of icaritin on nasopharyngeal cancer and its underlying mechanism using network pharmacology along with in vivo and in vitro experiments. Methods: MTT and clone formation assays were used to detect the effects of icaritin on the viability and proliferation of nasopharyngeal carcinoma cells, followed by the construction of a HONE1 xenograft tumor model to evaluate the anti-tumor efficacy of icaritin in vivo. A public database was used to predict prospective targets, built a protein-protein interaction (PPI) network, and analyze gene enrichment and biological processes. Based on network pharmacological data, cell cycle-related proteins were identified using western blotting. Besides, cell cycle distribution, apoptosis, and intracellular reactive oxygen species (ROS) generation were identified using flow cytometry. In addition, SA-β-Gal staining was performed to detect cellular senescence, and western blotting was performed to detect the expression of P53, P21, and other proteins to verify key signaling pathways. Results: Icaritin effectively inhibited the viability and proliferation of nasopharyngeal carcinoma cell lines and showed good anti-tumor activity against HONE1 nasopharyngeal carcinoma cells in vivo. Key protein targets, including AKT1, HSP90AA1, CDK4, CCND1, and EGFR, were screened using PPI network topology analysis. GO and KEGG analysis revealed that the cell cycle, p53 signaling, and cell senescence pathways may be the main regulatory pathways. Flow cytometry and western blot experiments showed that icaritin caused S-phase arrest and promoted an increase in ROS. SA-β-Gal staining showed that icaritin significantly induced cellular senescence, and western blotting showed that the expression of senescence-related proteins p53 and P21 increased significantly. Moreover, inhibition of ROS levels by N-Acetylcysteine (NAC) enhanced cell viability, reversed cellular senescence and reduced cellular senescence-associated protein expression. Conclusion: The results of network pharmacological analysis and in vivo and in vitro experiments showed that icaritin effectively inhibited the growth of nasopharyngeal carcinoma cells, promoted ROS production, induced cellular senescence, and inhibited tumor cells, which are related to the regulation of P53/P21 signal pathway.

The multifaceted role of STAT3 pathway and its implication as a potential therapeutic target in oral cancer

Oral cancer is one of the leading causes of cancer-related deaths, and it has become a matter of serious concern due to the alarming rise in its incidence rate worldwide. Despite recent advancements in oral cancer treatment strategies, there are no significant improvements in patient's survival rate. Among the numerous cell signaling pathways involved in oral cancer development and progression, STAT3 is known to play a multifaceted oncogenic role in shaping the tumor pathophysiology. STAT3 hyperactivation in oral cancer contributes to survival, proliferation, invasion, epithelial to mesenchymal transition, metastasis, immunosuppression, chemoresistance, and poor prognosis. A plethora of pre-clinical and clinical studies have documented the role of STAT3 in the initiation and development of oral cancer and showed that STAT3 inhibition holds significant potential in the prevention and treatment of this cancer. However, to date, targeting STAT3 activation mainly involves inhibiting the upstream signaling molecules such as JAK and IL-6 receptors. The major challenge in targeting STAT3 lies in the complexity of its phosphorylation- and dimerization-independent functions, which are not affected by disrupting the upstream regulators. The present review delineates the significance of the STAT3 pathway in regulating various hallmarks of oral cancer. In addition, it highlights the STAT3 inhibitors identified to date through various preclinical and clinical studies that can be employed for the therapeutic intervention in oral cancer treatment.

STAT3 pathway in cancers: Past, present, and future

Signal transducer and activator of transcription 3 (STAT3), a member of the STAT family, discovered in the cytoplasm of almost all types of mammalian cells, plays a significant role in biological functions. The duration of STAT3 activation in normal tissues is a transient event and is strictly regulated. However, in cancer tissues, STAT3 is activated in an aberrant manner and is induced by certain cytokines. The continuous activation of STAT3 regulates the expression of downstream proteins associated with the formation, progression, and metastasis of cancers. Thus, elucidating the mechanisms of STAT3 regulation and designing inhibitors targeting the STAT3 pathway are considered promising strategies for cancer treatment. This review aims to introduce the history, research advances, and prospects concerning the STAT3 pathway in cancer. We review the mechanisms of STAT3 pathway regulation and the consequent cancer hallmarks associated with tumor biology that are induced by the STAT3 pathway. Moreover, we summarize the emerging development of inhibitors that target the STAT3 pathway and novel drug delivery systems for delivering these inhibitors. The barriers against targeting the STAT3 pathway, the focus of future research on promising targets in the STAT3 pathway, and our perspective on the overall utility of STAT3 pathway inhibitors in cancer treatment are also discussed.

Chinese Herbal Medicine for Primary Liver Cancer Therapy: Perspectives and Challenges

Primary liver cancer (PLC) is one of the most common solid malignancies. However, PLC drug development has been slow, and first-line treatments are still needed; thus, studies exploring and developing alternative strategies for effective PLC treatment are urgently needed. Chinese herbal medicine (CHM) has long been applied in the clinic due to its advantages of low toxicity and targeting of multiple factors and pathways, and it has great potential for the development of novel natural drugs against PLC.

Purpose: This review aims to provide an update on the pharmacological mechanisms of Chinese patent medicines (CPMs) and the latest CHM-derived compounds for the treatment of PLC and relevant clinical evaluations.

Materials and Methods: A systematic search of English literature databases, Chinese literature, the Clinical Trials Registry Platform, and the Chinese Clinical Trial Registry for studies of CHMs for PLC treatment was performed.

Results: In this review, we summarize the clinical trials and mechanisms of CPMs for PLC treatment that have entered the clinic with the approval of the Chinese medicine regulatory authority. These CPMs included Huaier granules, Ganfule granules, Fufang Banmao capsules, Jinlong capsules, Brucea javanica oil emulsions, and compound kushen injections. We also summarize the latest in vivo, in vitro, and clinical studies of CHM-derived compounds against PLC: icaritin and ginsenoside Rg3. Dilemmas facing the development of CHMs, such as drug toxicity and low oral availability, and future developments are also discussed.

Conclusion: This review provides a deeper the understanding of CHMs as PLC treatments and provides ideas for the development of new natural drugs against PLC.

Phytochemicals in Cancer Immune Checkpoint Inhibitor Therapy

The interaction of immune checkpoint molecules in the tumor microenvironment reduces the anti-tumor immune response by suppressing the recognition of T cells to tumor cells. Immune checkpoint inhibitor (ICI) therapy is emerging as a promising therapeutic option for cancer treatment. However, modulating the immune system with ICIs still faces obstacles with severe immunogenic side effects and a lack of response against many cancer types. Plant-derived natural compounds offer regulation on various signaling cascades and have been applied for the treatment of multiple diseases, including cancer. Accumulated evidence provides the possibility of efficacy of phytochemicals in combinational with other therapeutic agents of ICIs, effectively modulating immune checkpoint-related signaling molecules. Recently, several phytochemicals have been reported to show the modulatory effects of immune checkpoints in various cancers in in vivo or in vitro models. This review summarizes druggable immune checkpoints and their regulatory factors. In addition, phytochemicals that are capable of suppressing PD-1/PD-L1 binding, the best-studied target of ICI therapy, were comprehensively summarized and classified according to chemical structure subgroups. It may help extend further research on phytochemicals as candidates of combinational adjuvants. Future clinical trials may validate the synergetic effects of preclinically investigated phytochemicals with ICI therapy.

Peroxidase-mimicking evodiamine/indocyanine green nanoliposomes for multimodal imaging-guided theranostics for oral squamous cell carcinoma

Here, evodiamine (EVO) and the photosensitizer indocyanine green (ICG) were integrated into a liposomal nanoplatform for noninvasive diagnostic imaging and combinatorial therapy against oral squamous cell carcinoma (OSCC). EVO, as an active component extracted from traditional Chinese medicine, not only functioned as an antitumor chemotherapeutic agent but was also capable of 68Ga-chelation, thus working as a contrast agent for positron emission tomography/computed tomography (PET/CT) imaging. Moreover, EVO could exhibit peroxidase-like catalytic activity, converting endogenous tumor H2O2 into cytotoxic reactive oxygen species (ROS), enabling Chemo catalytic therapy beyond the well-known chemotherapy effect of EVO. As proven by in vitro and in vivo experiments, guided by optical imaging and PET/CT imaging, we show that the theragnostic liposomes have a significant inhibiting effect on in situ tongue tumor through photodynamic therapy combined with chemodynamic chemotherapy.

Bioactive Compounds from Herbal Medicine Targeting Multiple Myeloma

Multiple myeloma (MM) is one of the most widespread hematological cancers. It is characterized by a clonal proliferation of malignant plasma cells in the bone marrow and by the overproduction of monoclonal proteins. In recent years, the survival rate of patients with multiple myeloma has increased significantly due to the use of transplanted stem cells and of the new therapeutic agents that have significantly increased the survival rate, but it still cannot be completely cured and therefore the development of new therapeutic products is needed. Moreover, many patients have various side effects and face the development of drug resistance to current therapies. The purpose of this review is to highlight the bioactive active compounds (flavonoids) and herbal extracts which target dysregulated signaling pathway in MM, assessed by in vitro and in vivo experiments or clinical studies, in order to explore their healing potential targeting multiple myeloma. Mechanistically, they demonstrated the ability to promote cell cycle blockage and apoptosis or autophagy in cancer cells, as well as inhibition of proliferation/migration/tumor progression, inhibition of angiogenesis in the tumor vascular network. Current research provides valuable new information about the ability of flavonoids to enhance the apoptotic effects of antineoplastic drugs, thus providing viable therapeutic options based on combining conventional and non-conventional therapies in MM therapeutic protocols.

STAT3 transcription factor as target for anti-cancer therapy

STATs constitute a large family of transcription activators and transducers of signals that have an important role in many cell functions as regulation of proliferation and differentiation of the cell also regulation of apoptosis and angiogenesis. STAT3 as a member of that family, recently was discovered to have a vital role in progression of different types of cancers. The activation of STAT3 was observed to regulate multiple gene functions during cancer-like cell proliferation, differentiation, apoptosis, metastasis, inflammation, immunity, cell survival, and angiogenesis. The inhibition of STAT3 activation has been an important target for cancer therapy. Inhibitors of STAT3 have been used for a long time for treatment of many types of cancers like leukemia, melanoma, colon, and renal cancer. In this review article, we summarize and discuss different drugs inhibiting the action of STAT3 and used in treatment of different types of cancer.

Molecular and cellular basis of the anticancer activity of the prenylated flavonoid icaritin in hepatocellular carcinoma

The prenylated flavonoid icaritin (ICT) is currently undergoing phase 3 clinical trial for the treatment of advanced hepatocellular carcinoma (HCC), based on a solid array of preclinical and clinical data. The antitumor activity originates from the capacity of the drug to modulate several signaling effectors in cancer cells, mainly the estrogen receptor splice variant ERα36, the transcription factors STAT3 and NFκB, and the chemokine receptor CXCR4. Recent studies have implicated additional components, including different microRNAs, the generation of reactive oxygen species and the targeting of sphingosine kinase-1. ICT also engages the RAGE-HMGB1 signaling route and modulates the apoptosis/autophagy crosstalk to promote its anticancer activity. In addition, ICT exerts profound changes on the tumor microenvironment to favor an immune-response. Collectively, these multiple biochemical and cellular characteristics confer to ICT a robust activity profile which can be exploited to treat HCC, as well as other cancers, including glioblastoma and onco-hematological diseases such as chronic myeloid leukemia. This review provides an update of the pharmacological properties of ICT and its metabolic characteristics. It also addresses the design of derivatives, including both natural products and synthetic molecules, such as SNG1153 also in clinical trial. The prenylated flavonoid ICT deserves attention as a multifunctional natural product potentially useful to improve the treatment of advanced hepatocellular carcinoma.

Natural product-derived icaritin exerts anti-glioblastoma effects by positively modulating estrogen receptor β

Glioblastoma is the most common malignancy of the central nervous system, and patients typically have a poor prognosis. Previous studies indicate a gender bias in the development of glioblastoma; women are at a lower risk compared with men, suggesting that estrogen may confer protective effects. Icaritin, a prenylflavonoid derivative from a Chinese herb of the Epimedium genus, selectively regulates the estrogen receptor (ER) and possesses anti-cancer properties. The aim of the present study was to investigate the protective effects of icaritin on glioblastoma and its underlying mechanisms, with a particular focus on its association with the ER. The results demonstrated that icaritin inhibited the growth of C6 and U87-MG glioblastoma cells in a dose- and time-dependent manner. At a concentration of 12.5 µM, icaritin induced apoptosis, which was characterized by the increased expression of the cleaved forms of caspases 3, 7, 8 and 9 and poly (ADP-ribose) polymerase, downregulation of BCL2 apoptosis regulator and upregulation of BCL2-associated X, apoptosis regulator expression. Additionally, icaritin inhibited the migration of C6 and U87-MG cells. The protein expression levels of matrix metalloproteinase (MMP)-2 and MMP-9 were also downregulated following icaritin treatment. Furthermore, icaritin treatment increased the expression of estrogen receptor (ER)β and the phosphatase and tensin (PTEN) homolog oncoprotein, thus reducing the expression of downstream targets of PTEN; protein kinase B (Akt) and phosphorylated Akt. Subsequent experiments demonstrated that icaritin cooperates with 17β-estradiol to inhibit the growth of glioblastoma cells, and the inhibition of ERβ with the ERβ-specific antagonist ICI 182,780, attenuated the anti-glioblastoma effects of icaritin. In conclusion, the results of the present study demonstrate that the anti-glioblastoma effects of icaritin may be mediated by its modulation of ERβ.

The mTOR-glycolytic pathway promotes T-cell immunobiology in oral lichen planus

Oral lichen planus (OLP) is a T-cell-mediated inflammatory mucosal disease. T cells require rapid metabolic reprogramming for their effector functions after activation by immunologic stimuli. The mammalian target of rapamycin (mTOR) is a central player in the metabolic reprogramming and immune responses of T cells. The present study investigated the role of mTOR in the immunometabolism of OLP. mTOR and its direct target eukaryotic initiation factor 4E binding protein 1 (4E-BP1) were highly phosphorylated in peripheral T cells of OLP patients. Rapamycin-mediated blockage of mTOR activation restrained both T-cell proliferation and DNA synthesis, promoted apoptosis, and decreased Th1/Th2 and Th17/Treg ratios. Dual blockage of mTOR and phosphatidylinositol 3-kinase (PI3K) exerted stronger inhibition on T-cell immunobiology than selective repression of PI3K alone. Rapamycin also blocked the glycolytic pathway in T cells. Moreover, glucose-induced activation of mTOR-glycolytic pathway increased T-cell proliferation, DNA synthesis, and the Th17/Treg ratio, and decreased T-cell apoptosis. In contrast, inhibition of glycolysis by 2-Deoxy-d-glucose (2-DG) yielded the opposite effects on T-cell immunobiology by blocking the mTOR pathway. In conclusion, enhanced activation of the mTOR-glycolytic pathway promoted T-cell immunobiology, suggesting that dysregulation of immunometabolism might be associated with T-cell dysfunction in OLP.

Autophagy modulators for the treatment of oral and esophageal squamous cell carcinomas

Oral squamous cell carcinomas (OSCC) and esophageal squamous cell carcinomas (ESCC) exhibit a survival rate of less than 60% and 40%, respectively. Late-stage diagnosis and lack of effective treatment strategies make both OSCC and ESCC a significant health burden. Autophagy, a lysosome-dependent catabolic process, involves the degradation of intracellular components to maintain cell homeostasis. Targeting autophagy has been highlighted as a feasible therapeutic strategy with clinical utility in cancer treatment, although its associated regulatory mechanisms remain elusive. The detection of relevant biomarkers in biological fluids has been anticipated to facilitate early diagnosis and/or prognosis for these tumors. In this context, recent studies have indicated the presence of specific proteins and small RNAs, detectable in circulating plasma and serum, as biomarkers. Interestingly, the interplay between biomarkers (eg, exosomal microRNAs) and autophagic processes could be exploited in the quest for targeted and more effective therapies for OSCC and ESCC. In this review, we give an overview of the available biomarkers and innovative targeted therapeutic strategies, including the application of autophagy modulators in OSCC and ESCC. Additionally, we provide a viewpoint on the state of the art and on future therapeutic perspectives combining the early detection of relevant biomarkers with drug discovery for the treatment of OSCC and ESCC.

STAT3 Promotes Invasion and Aerobic Glycolysis of Human Oral Squamous Cell Carcinoma via Inhibiting FoxO1

Signal transducer and activator of transcription 3 (STAT3), a previously accepted tumor-promoting protein in various malignancies, plays a key role in the process of cancer glycolysis. However, the role and potential mechanism of STAT3 in aerobic glycolysis and progression of oral squamous cell carcinoma (OSCC) has not been explored. In the present study, we demonstrated that STAT3 knockdown remarkably inhibited migration, invasion, expressions of epithelial-mesenchymal transition (EMT) markers, and aerobic glycolysis of OSCC cells by up-regulation of FoxO1. Consistently, the expression of nuclear Tyr705-phosphorylated STAT3, an active form of STAT3, was significantly elevated in OSCC tissues compared with adjacent normal tissues, and increased nuclear staining of Tyr705-phosphorylated STAT3 was associated with metastasis and shorter overall survival. Moreover, FoxO1, which was also mainly expressed in OSCC specimens, decreased in poorly-differentiated tissues compared with the relatively well-differentiated ones, and inversely correlated with the expression of nuclear Tyr705-phosphorylated STAT3 from patients with OSCC. Hence, our findings collectively characterized the contributing role of STAT3/FoxO1 in invasion and aerobic glycolysis of OSCC cells, which may lead to the worse clinical outcome.

Icaritin: A Novel Natural Candidate for Hematological Malignancies Therapy

Hematological malignancies including leukemia and lymphoma can severely impact human health. With the current therapies combined with chemotherapy, stem cell transplantation, radiotherapy, and immunotherapy, the prognosis of hematologic malignancies improved significantly. However, most hematological malignancies are still incurable. Therefore, research for novel treatment options was continuing with the natural product as one source. Icaritin is a compound extracted from a traditional Chinese herb, Epimedium Genus, and demonstrated an antitumor effect in various neoplasms including hematological malignancies such as leukemia, lymphoma, and multiple myeloma. In hematological malignancies, icaritin showed multiple cytotoxic effects to induce apoptosis, arrest the cell cycle, inhibit proliferation, promote differentiation, restrict metastasis and infiltration, and suppress the oncogenic virus. The proved underlying mechanisms of the cytotoxic effects of icaritin are different in various cell types of hematological malignancies but associated with the critical cell signal pathway, including PI3K/Akt, JAK/STAT3, and MAPK/ERK/JNK. Although the primary target of icaritin is still unspecified, the existing evidence indicates that icaritin is a potential novel therapeutic agent for neoplasms as with hematological malignancies. Here, in the field of hematology, we reviewed the reported activity of icaritin in hematologic malignancies and the underlying mechanisms and recognized icaritin as a candidate for therapy of hematological malignancies.

Reactive oxygen species induced by icaritin promote DNA strand breaks and apoptosis in human cervical cancer cells

Increased production of reactive oxygen species (ROS) is a distinct feature of various types of cancer. ROS drive tumor progression and render cancer cells vulnerable to additional oxidative insult. The various natural herb compounds have been shown to induce additional production of ROS in cancer cells, although the physiological implications of ROS under these conditions are not fully determined. In the present study, icaritin, a natural compound derived from the medicinal plants Epimedium, was demonstrated to potently suppresses the proliferation of human HeLa and SiHa cervical cancer cells, without similar affects on non-cancerous CCD-1095Sk fibroblasts and 293 cells, as measured by MTT and colony formation assays. Icaritin treatment caused a rapid increase in ROS in HeLa and SiHa cells, which was followed by a prominent increase in the number of DNA strand breaks. Consequently, the levels of the pro-apoptotic protein Bax and activated caspase 3 and 9 enzymes were increased, while the levels of the anti-apoptotic proteins Bcl-2 and XIAP were downregulated. These protein expression changes were accompanied by marked induction of apoptosis in icaritin-treated cancer cells. The results suggested that the icaritin-induced ROS overload promoted cancer cell death via induction of extensive oxidative DNA damage, which subsequently resulted in large numbers of DNA strand breaks and the activation of the intrinsic apoptotic pathway.

Apoptosis induced by methanol extract of Potentilla discolor in human mucoepidermoid carcinoma cells through STAT3/PUMA signaling axis

Potentilla discolor has been used in traditional Chinese medicine for the treatment of hyperglycemia. However, the potential role of Potentilla discolor against cancer and its mode of action remain to be fully elucidated. The present study explored the apoptotic effect of methanol extract of Potentilla discolor (MEPD) in human mucoepidermoid carcinoma (MEC) cell lines of salivary glands. MEPD markedly suppressed the growth and induced apoptotic cell death in MC3 and YD15 cells. MEPD treatment significantly upregulated the expression of PUMA and reduced STAT3 phosphorylation. Overexpression of STAT3 partially recovered the growth of MEC cells inhibited by MEPD. In addition, dephosphorylation of STAT3 by cryptotanshinone (a potent STAT3 inhibitor) was sufficient to inhibit the growth of MEC cells and induce apoptosis via affecting PUMA protein. These results suggest that MEPD has a potential anticancer property via the STAT3/PUMA signaling axis in human MEC cells of salivary gland.

Autophagy Induced by Areca Nut Extract Contributes to Decreasing Cisplatin Toxicity in Oral Squamous Cell Carcinoma Cells: Roles of Reactive Oxygen Species/AMPK Signaling

Chewing areca nut is closely associated with oral squamous cell carcinoma (OSCC). The current study aimed to investigate potential associations between areca nut extract (ANE) and cisplatin toxicity in OSCC cells. OSCC cells (Cal-27 and Scc-9) viability and apoptosis were analyzed after treatment with ANE and/or cisplatin. The expressions of proteins associated with autophagy and the AMP-activated protein kinase (AMPK) signaling network were evaluated. We revealed that advanced OSCC patients with areca nut chewing habits presented higher LC3 expression and poorer prognosis. Reactive oxygen species (ROS)-mediated autophagy was induced after pro-longed treatment of ANE (six days, 3 μg). Cisplatin toxicity (IC₅₀, 48 h) was decreased in OSCC cells after ANE treatment (six days, 3 μg). Cisplatin toxicity could be enhanced by reversed autophagy by pretreatment of 3-methyladenine (3-MA), N-acetyl-l-cysteine (NAC), or Compound C. Cleaved-Poly-(ADP-ribose) polymerase (cl-PARP) and cleaved-caspase 3 (cl-caspase 3) were downregulated in ANE-treated OSCC cells in the presence of cisplatin, which was also reversed by NAC and Compound C. Collectively, ANE could decrease cisplatin toxicity of OSCC by inducing autophagy, which involves the ROS and AMPK/mTOR signaling pathway.