Baicalein inhibits the invasion of gastric cancer cells by suppressing the activity of the p38 signaling pathway

Flavonoids and Gastric Cancer Therapy: From Signaling Pathway to Therapeutic Significance

Gastric cancer (GC) is a prevalent gastrointestinal tumor characterized by high mortality and recurrence rates. Current treatments often have limitations, prompting researchers to explore novel anti-tumor substances and develop new drugs. Flavonoids, natural compounds with diverse biological activities, are gaining increasing attention in this regard. We searched from PubMed, Web of Science, SpringerLink and other databases to find the relevant literature in the last two decades. Using "gastric cancer", "stomach cancers", "flavonoid", "bioflavonoid", "2-Phenyl-Chromene" as keywords, were searched, then analyzed and summarized the mechanism of flavonoids in the treatment of GC. It was revealed that the anti-tumor mechanism of flavonoids involves inhibiting tumor growth, proliferation, invasion, and metastasis, as well as inducing cell death through various processes such as apoptosis, autophagy, ferroptosis, and pyroptosis. Additionally, combining flavonoids with other chemotherapeutic agents like 5-FU and platinum compounds can potentially reduce chemoresistance. Flavonoids have also demonstrated enhanced biological activity when used in combination with other natural products. Consequently, this review proposes innovative perspectives for the development of flavonoids as new anti-GC agents.

The most recent progress of baicalein in its anti-neoplastic effects and mechanisms

Problems, such as toxic side effects and drug resistance of chemoradiotherapy, target therapy and immunotherapy accompanying the current anti-cancer treatments, have become bottlenecks limiting the clinical benefit for patients. Therefore, it is urgent to find promising anti-cancer strategies with higher efficacy and lesser side effects. Baicalein, a flavonoid component derived from the Chinese medicine scutellaria baicalensis, has been widely studied for its remarkable anti-cancer activity in multiple types of malignancies both at the molecular and cellular levels. Baicalein exerts its anti-tumor effects by inhibiting angiogenesis, invasion and migration, inducing cell apoptosis and cell cycle arrest, as well as regulating cell autophagy, metabolism, the tumor microenvironment and cancer stem cells with no obvious toxic side effects. The role of classic signaling pathways, such as PI3K/AKT/mTOR, MAPK, AMPK, Wnt/β-catenin, JAK/STAT3, MMP-2/-9, have been highlighted as the major targets for baicalein exerting its anti-malignant potential. Besides, baicalein can regulate the relevant non-coding RNAs, such as lncRNAs, miRNAs and circ-RNAs, to inhibit tumorigenesis and progression. In addition to the mentioned commonalities, baicalein shows some specific anti-tumor characteristics in some specific cancer types. Moreover, the preclinical studies of the combination of baicalein and chemoradiotherapy pave the way ahead for developing baicalein as an adjunct treatment with chemoradiotherapy. Our aim is to summary the role of baicalein in different types of cancer with its mechanisms based on in vitro and in vivo experiments, hoping providing proof for baicalein serving as an effective and safe compound for cancer treatment in clinic in the future.

Progress and prospects of biomarker-based targeted therapy and immune checkpoint inhibitors in advanced gastric cancer

Gastric cancer and gastroesophageal junction cancer represent the leading cause of tumor-related death worldwide. Although advances in immunotherapy and molecular targeted therapy have expanded treatment options, they have not significantly altered the prognosis for patients with unresectable or metastatic gastric cancer. A minority of patients, particularly those with PD-L1-positive, HER-2-positive, or MSI-high tumors, may benefit more from immune checkpoint inhibitors and/or HER-2-directed therapies in advanced stages. However, for those lacking specific targets and unique molecular features, conventional chemotherapy remains the only recommended effective and durable regimen. In this review, we summarize the roles of various signaling pathways and further investigate the available targets. Then, the current results of phase II/III clinical trials in advanced gastric cancer, along with the superiorities and limitations of the existing biomarkers, are specifically discussed. Finally, we will offer our insights in precision treatment pattern when encountering the substantial challenges.

Baicalin and baicalein in modulating tumor microenvironment for cancer treatment: A comprehensive review with future perspectives

Cancer is a leading cause of death worldwide. The burden of cancer incidence and mortality is increasing rapidly. New approaches to cancer prevention and treatment are urgently needed. Natural products are reliable and powerful sources for anticancer drug discovery. Baicalin and baicalein, two major flavones isolated from Scutellaria baicalensis Georgi, a multi-purpose traditional medicinal plant in China, exhibit anticancer activities against multiple cancers. Of note, these phytochemicals exhibit extremely low toxicity to normal cells. Besides their cytotoxic and cytostatic activities toward diverse tumor cells, recent studies demonstrated that baicalin and baicalein modulate a variety of tumor stromal cells and extracellular matrix (ECM) in the tumor microenvironment (TME), which is essential for tumorigenesis, cancer progression and metastasis. In this review, we summarize the therapeutic potential and the mechanism of action of baicalin and baicalein in the regulation of tumor microenvironmental immune cells, endothelial cells, fibroblasts, and ECM that reshape the TME and cancer signaling, leading to inhibition of tumor angiogenesis, progression, and metastasis. In addition, we discuss the biotransformation pathways of baicalin and baicalein, related therapeutic challenges and the future research directions to improve their bioavailability and clinical anticancer applications. Recent advances of baicalin and baicalein warrant their continued study as important natural ways for cancer interception and therapy.

Baicalein facilitates gastric cancer cell apoptosis by triggering endoplasmic reticulum stress via repression of the PI3K/AKT pathway

OBJECTIVE

Gastric cancer (GC) remains a prevailing threat to life. Baicalein exhibits anti-cancer properties. This study estimated the mechanism of baicalein in GC cell apoptosis by mediating endoplasmic reticulum stress (ERS) through the PI3K/AKT pathway.

METHODS

After treatment with different concentrations of baicalein, GC cell (HGC-27 and AGS) viability was detected by MTT assay. AGS cells more sensitive to baicalein treatment were selected as study subjects. The IC50 of baicalein on AGS cells was determined. Colony formation, cell cycle, and apoptosis were detected using crystal violet staining and flow cytometry. Levels of ERS-related and BTG3/PI3K/AKT pathway-related proteins were determined by Western blot. Intracellular Ca²⁺ level was measured using Fluo-3 AM fluorescence working solution. GC mouse models were established by subcutaneously injecting AGS cells into the right rib and were intragastrically administrated with baicalein. Tumor volume and weight were recorded. Expression of Ki67 in tumor tissues and positive expression of apoptotic cells were detected by immunohistochemistry and TUNEL staining.

RESULTS

Baicalein inhibited cell proliferation and induced G0/G1 arrest and apoptosis by regulating the cell cycle, and triggered ERS in GC cells. Baicalein impeded the PI3K/AKT pathway by activating BTG3, thereby triggering ERS and inducing apoptosis. BTG3 inhibition reversed baicalein-induced apoptosis and ERS. Baicalein regulated GC cells in a concentration-dependent manner. Moreover, in xenograft mice, baicalein prevented tumor growth, decreased Ki67-positive cells, activated BTG3, and inhibited the PI3K/AKT pathway, thus activating ERS and increasing apoptotic cells.

CONCLUSION

Baicalein facilitates GC cell apoptosis by triggering ERS via repression of the PI3K/AKT pathway.

Traditional Chinese medicine for transformation of gastric precancerous lesions to gastric cancer: A critical review

Gastric cancer (GC) is a common gastrointestinal tumor. Gastric precancerous lesions (GPL) are the last pathological stage before normal gastric mucosa transforms into GC. However, preventing the transformation from GPL to GC remains a challenge. Traditional Chinese medicine (TCM) has been used to treat gastric disease for millennia. A series of TCM formulas and active compounds have shown therapeutic effects in both GC and GPL. This article reviews recent progress on the herbal drugs and pharmacological mechanisms of TCM in preventing the transformation from GPL to GC, especially focusing on anti-inflammatory, anti-angiogenesis, proliferation, and apoptosis. This review may provide a meaningful reference for the prevention of the transformation from GPL to GC using TCM.

Crosstalk between xanthine oxidase (XO) inhibiting and cancer chemotherapeutic properties of comestible flavonoids- a comprehensive update

Gout is an inflammatory disease caused by metabolic disorder or genetic inheritance. People throughout the world are strongly dependent on ethnomedicine for the treatment of gout and some receive satisfactory curative treatment. The natural remedies as well as established drugs derived from natural sources or synthetically made exert their action by mechanisms that are closely associated with anticancer treatment mechanisms regarding inhibition of xanthine oxidase, feedback inhibition of de novo purine synthesis, depolymerization and disappearance of microtubule, inhibition of NF-ĸB activation, induction of TRAIL, promotion of apoptosis, and caspase activation and proteasome inhibition. Some anti-gout and anticancer novel compounds interact with same receptors for their action, e.g., colchicine and colchicine analogues. Dietary flavonoids, i.e., chrysin, kaempferol, quercetin, fisetin, pelargonidin, apigenin, luteolin, myricetin, isorhamnetin, phloretinetc etc. have comparable IC₅₀ values with established anti-gout drug and effective against both cancer and gout. Moreover, a noticeable number of newer anticancer compounds have already been isolated from plants that have been using by local traditional healers and herbal practitioners to treat gout. Therefore, the anti-gout plants might have greater potentiality to become selective candidates for screening of newer anticancer leads.

Signaling pathways and therapeutic interventions in gastric cancer

Gastric cancer (GC) ranks fifth in global cancer diagnosis and fourth in cancer-related death. Despite tremendous progress in diagnosis and therapeutic strategies and significant improvements in patient survival, the low malignancy stage is relatively asymptomatic and many GC cases are diagnosed at advanced stages, which leads to unsatisfactory prognosis and high recurrence rates. With the recent advances in genome analysis, biomarkers have been identified that have clinical importance for GC diagnosis, treatment, and prognosis. Modern molecular classifications have uncovered the vital roles that signaling pathways, including EGFR/HER2, p53, PI3K, immune checkpoint pathways, and cell adhesion signaling molecules, play in GC tumorigenesis, progression, metastasis, and therapeutic responsiveness. These biomarkers and molecular classifications open the way for more precise diagnoses and treatments for GC patients. Nevertheless, the relative significance, temporal activation, interaction with GC risk factors, and crosstalk between these signaling pathways in GC are not well understood. Here, we review the regulatory roles of signaling pathways in GC potential biomarkers, and therapeutic targets with an emphasis on recent discoveries. Current therapies, including signaling-based and immunotherapies exploited in the past decade, and the development of treatment for GC, particularly the challenges in developing precision medications, are discussed. These advances provide a direction for the integration of clinical, molecular, and genomic profiles to improve GC diagnosis and treatments.

Natural Small Molecules in Gastrointestinal Tract and Associated Cancers: Molecular Insights and Targeted Therapies

Gastric cancer is one of the most common cancers of the gastrointestinal tract. Although surgery is the primary treatment, serious maladies that dissipate to other parts of the body may require chemotherapy. As there is no effective procedure to treat stomach cancer, natural small molecules are a current focus of research interest for the development of better therapeutics. Chemotherapy is usually used as a last resort for people with advanced stomach cancer. Anti-colon cancer chemotherapy has become increasingly effective due to drug resistance and sensitivity across a wide spectrum of drugs. Naturally-occurring substances have been widely acknowledged as an important project for discovering innovative medications, and many therapeutic pharmaceuticals are made from natural small molecules. Although the beneficial effects of natural products are as yet unknown, emerging data suggest that several natural small molecules could suppress the progression of stomach cancer. Therefore, the underlying mechanism of natural small molecules for pathways that are directly involved in the pathogenesis of cancerous diseases is reviewed in this article. Chemotherapy and molecularly-targeted drugs can provide hope to colon cancer patients. New discoveries could help in the fight against cancer, and future stomach cancer therapies will probably include molecularly formulated drugs.

Revealing the Active Compounds and Mechanism of Banxia Xiexin Decoction Against Gastric Ulcer by Network Pharmacology and Molecular Docking

Gastric ulcer (GU) is a clinically common gastrointestinal disease with a long disease course that frequently reoccurs. Banxia Xiexin decoction (BXD), a traditional Chinese medicine prescription, has a prominent protective effect against GU. Nonetheless, the therapeutic mechanisms of BXD against GU remain elusive. In this study, a rat model of GU was established by gavage with 95% ethanol, and BXD significantly attenuated the inflammatory effect of GU in rats. An “active ingredient–target” interaction and GU protein–protein interaction networks were constructed based on system biology, which could screen out the crucial active ingredients. The target protein–protein interaction network for the BXD treatment of GU was constructed to identify the key target proteins with network topology parameters. The DAVID database was then used to perform Gene Ontology and Kyoto encyclopedia of genes and genomes enrichment analysis on the proteins targeted by BXD in the treatment of GU. Finally, molecular docking technology was used to study the interactions between key active ingredients and core target proteins. A total of 89 active ingredients of BXD were screened and 63 target proteins of BXD in the treatment of GU were identified. Through the analysis of protein–protein interaction and the active ingredient–target protein network diagram, it was found that tumor necrosis factor-α(TNF-α), AKT1, and PTGS2 may play a key role in the treatment of GU by BXD. Molecular docking showed that these 3 core target proteins had a good affinity with the main components of BXD, including baicalein, norwogonin, and skullcapflavone II. The mechanism of BXD against GU may involve the inhibition of inflammatory response and oxidative stress, involving signaling pathways such as TNF, hypoxia-inducible factor-1, and mitogen-activated protein kinase. Network pharmacology and molecular docking technology indicated the key active ingredients, target proteins, and signal pathways that may be the biological basis of BXD in the treatment of GU.

Bioactive components of Banxia Xiexin Decoction for the treatment of gastrointestinal diseases based on flavor-oriented analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Banxia Xiexin Decoction (BXD) was first recorded in a Chinese medical classic, Treatise on Febrile Diseases and Miscellaneous Diseases, which was written in the Eastern Han dynasty of China. This ancient prescription consists of seven kinds of Chinese herbal medicine, namely, Pinellia ternata, Rhizoma Coptidis, Radix scutellariae, Rhizoma Zingiberis, Ginseng, Jujube, and Radix Glycyrrhizaepreparata. In clinic practice, its original application in China mainly has focused on the treatment of chronic gastritis for several hundred years. BXD is also effective in treating other gastrointestinal diseases (GIDs) in modern medical application. Despite available literature support and clinical experience, the treatment mechanisms or their relationships with the bioactive compounds in BXD responsible for its pharmacological actions, still need further explorations in more diversified channels. According to the analysis based on the five-flavor theory of TCM, BXD is traditionally viewed as the most representative prescription for pungent-dispersion, bitter-purgation and sweet-tonification. Consequently, based on the flavor-oriented analysis, the compositive herbs in BXD can be divided into three flavor groups, namely, the pungent, bitter, and sweet groups, each of which has specific active ingredients that are possibly relevant to GID treatment.

AIM OF THE REVIEW

This paper summarized recent literatures on BXD and its bioactive components used in GID treatment, and provided the pharmacological or chemical basis for the further exploration of the ancient prescription and the relative components.

METHOD

ology: Relevant literature was collected from various electronic databases such as Pubmed, Web of Science, and China National Knowledge Infrastructure (CNKI). Citations were based on peer-reviewed articles published in English or Chinese during the last decade.

RESULTS

Multiple components were found in the pungent, bitter, and sweet groups in BXD. The corresponding bioactive components include gingerol, shogaol, stigmasterol, and β-sitosterol in the pungent group; berberine, palmatine, coptisine, baicalein, and baicalin in the bitter group; and ginsenosides, polysaccharides, liquiritin, and glycyrrhetinic acid in the sweet group. These components have been found directly or indirectly responsible for the remarkable effects of BXD on GID.

CONCLUSION

This review provided some valuable reference to further clarify BXD treatment for GID and their possible material basis, based on the perspective of the flavor-oriented analysis.

An overview of pharmacological activities of baicalin and its aglycone baicalein: New insights into molecular mechanisms and signaling pathways

The flavonoids, baicalin, and its aglycone baicalein possess multi-fold therapeutic properties and are mainly found in the roots of Oroxylum indicum (L.) Kurz and Scutellaria baicalensis Georgi. These flavonoids have been reported to possess various pharmacological properties, including antibacterial, antiviral, anticancer, anticonvulsant, anti-oxidant, hepatoprotective, and neuroprotective effects. The pharmacological properties of baicalin and baicalein are due to their abilities to scavenge reactive oxygen species (ROS) and interaction with various signaling molecules associated with apoptosis, inflammation, autophagy, cell cycle, mitochondrial dynamics, and cytoprotection. In this review, we summarized the molecular mechanisms underlying the chemopreventive and chemotherapeutic applications of baicalin and baicalein in the treatment of cancer and inflammatory diseases. In addition, the preventive effects of baicalin and baicalein on mitochondrial dynamics and functions were highlighted with a particular emphasis on their anti-oxidative and cytoprotective properties. The current review highlights could be useful for future prospective studies to further improve the pharmacological applications of baicalein and baicalin. These studies should define the threshold for optimal drug exposure, dose optimization and focus on therapeutic drug monitoring, objective disease markers, and baicalin/baicalein drug levels.

Chiral Flavonoids as Antitumor Agents

Flavonoids are a group of natural products with a great structural diversity, widely distributed in plant kingdom. They play an important role in plant growth, development and defense against aggressors. Flavonoids show a huge variety of biological activities such as antioxidant, anti-inflammatory, anti-mutagenic, antimicrobial and antitumor, being able to modulate a large diversity of cellular enzymatic activities. Among natural flavonoids, some classes comprise chiral molecules including flavanones, flavan-3-ols, isoflavanones, and rotenoids, which have one or more stereogenic centers. Interestingly, in some cases, individual compounds of enantiomeric pairs have shown different antitumor activity. In nature, these compounds are mainly biosynthesized as pure enantiomers. Nevertheless, they are often isolated as racemates, being necessary to carry out their chiral separation to perform enantioselectivity studies. Synthetic chiral flavonoids with promising antitumor activity have also been obtained using diverse synthetic approaches. In fact, several new chiral bioactive flavonoids have been synthesized by enantioselective synthesis. Particularly, flavopiridol was the first cyclin-dependent kinase (CDK) inhibitor which entered clinical trials. The chiral pool approaches using amino acid as chiral building blocks have also been reported to achieve small libraries of chrysin derivatives with more potent in vitro growth inhibitory effect than chrysin, reinforcing the importance of the introduction of chiral moieties to improve antitumor activity. In this work, a literature review of natural and synthetic chiral flavonoids with antitumor activity is reported for the first time.

Deciphering genes associated with diffuse large B-cell lymphoma with lymphomatous effusions: A mutational accumulation scoring approach

Introduction

Earlier studies have shown that lymphomatous effusions in patients with diffuse large B-cell lymphoma (DLBCL) are associated with a very poor prognosis, even worse than for non-effusion-associated patients with stage IV disease. We hypothesized that certain genetic abnormalities were associated with lymphomatous effusions, which would help to identify related pathways, oncogenic mechanisms, and therapeutic targets.

Methods

We compared whole-exome sequencing on DLBCL samples involving solid organs (n = 22) and involving effusions (n = 9). We designed a mutational accumulation-based approach to score each gene and used mutation interpreters to identify candidate pathogenic genes associated with lymphomatous effusions. Moreover, we performed gene-set enrichment analysis from a microarray comparison of effusion-associated versus non-effusion-associated DLBCL cases to extract the related pathways.

Results

We found that genes involved in identified pathways or with high accumulation scores in the effusion-based DLBCL cases were associated with migration/invasion. We validated expression of 8 selected genes in DLBCL cell lines and clinical samples: MUC4, SLC35G6, TP53BP2, ARAP3, IL13RA1, PDIA4, HDAC1 and MDM2, and validated expression of 3 proteins (MUC4, HDAC1 and MDM2) in an independent cohort of DLBCL cases with (n = 31) and without (n = 20) lymphomatous effusions. We found that overexpression of HDAC1 and MDM2 correlated with the presence of lymphomatous effusions, and HDAC1 overexpression was associated with the poorest prognosis. 

Conclusion

Our findings suggest that DLBCL associated with lymphomatous effusions may be associated mechanistically with TP53-MDM2 pathway and HDAC-related chromatin remodeling mechanisms.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40364-021-00330-8.

Current Advances and Outlook in Gastric Cancer Chemoresistance: A Review

BACKGROUND

Surgical resection of the lesion is the standard primary treatment of gastric cancer. Unfortunately, most patients are already in the advanced stage of the disease when they are diagnosed with gastric cancer. Alternative therapies, such as radiation therapy and chemotherapy, can achieve only very limited benefits. The emergence of cancer drug resistance has always been the major obstacle to the cure of tumors. The main goal of modern cancer pharmacology is to determine the underlying mechanism of anticancer drugs.

OBJECTIVE

Here, we mainly review the latest research results related to the mechanism of chemotherapy resistance in gastric cancer, the application of natural products in overcoming the chemotherapy resistance of gastric cancer, and the new strategies currently being developed to treat tumors based on immunotherapy and gene therapy.

CONCLUSION

The emergence of cancer drug resistance is the main obstacle in achieving alleviation and final cure for gastric cancer. Mixed therapies are considered to be a possible way to overcome chemoresistance. Natural products are the main resource for discovering new drugs specific for treating chemoresistance, and further research is needed to clarify the mechanism of natural product activity in patients. .

MiR-3663-3p participates in the anti-hepatocellular carcinoma proliferation activity of baicalein by targeting SH3GL1 and negatively regulating EGFR/ERK/NF-κB signaling

Baicalein is a purified flavonoid that exhibits anticancer effects in hepatocellular carcinoma (HCC). However, its underlying molecular mechanisms remain largely unclear. In this study, we found that baicalein inhibited HCC cell growth, induced apoptosis, and blocked cell cycle arrest at the S phase in vitro, as well as reduced HCC tumor volume and weight in vivo. Quantitative reverse transcriptase-PCR (qRT-PCR) results suggested that miR-3663-3p was downregulated in HCC tissues. After baicalein treatment, miR-3663-3p expression was upregulated in HCC cells. Transfection of miR-3663-3p suppressed HCC cell proliferation and colony formation, increased the proportion of apoptotic cells in vitro, and reduced the volume and weight of tumors in vivo. The results of dual-luciferase reporter assay showed that miR-3663-3p could directly bind to the 3'-UTR of SH3GL1. SH3GL1 overexpression partly reduced the growth-inhibiting effect of miR-3663-3p. Both baicalein treatment and miR-3663-3p overexpression downregulated the expression of SH3GL1 and inactivated the Erk1/2, p-NF-κB/p65, and EGFR signaling pathways. Overall, our data suggest that baicalein may act as a novel HCC suppressor, and that the miR-3663-3p/SH3GL1/EGFR/ERK/NF-κB pathway plays a vital role in HCC progression. Thus, baicalein treatment or miR-3663-3p induction may be a promising strategy for HCC therapy.

Baicalein Induces Apoptosis of Pancreatic Cancer Cells by Regulating the Expression of miR-139-3p and miR-196b-5p

Pancreatic cancer is a common malignant tumor with a high incidence and mortality rate. The prognosis of patients with pancreatic cancer is considerably poor due to the lack of effective treatment in clinically. Despite numerous studies have revealed that baicalein, a natural product, is responsible for suppressing multiple cancer cells proliferation, motility and invasion. The mechanism by which baicalein restraining pancreatic cancer progression remains unclear. In this study, we firstly verified that baicalein plays a critical role in inhibiting pancreatic tumorigenesis in vitro and in vivo. Then we analyzed the alteration of microRNAs (miRNAs) expression levels in Panc-1 cells incubated with DMSO, 50 and 100 μM baicalein by High-Throughput sequencing. Intriguingly, we observed that 20 and 39 miRNAs were accordingly up- and down-regulated through comparing Panc-1 cells exposed to 100 μM baicalein with the control group. Quantitative PCR analysis confirmed that miR-139-3p was the most up-regulated miRNA after baicalein treatment, while miR-196b-5p was the most down-regulated miRNA. Further studies showed that miR-139-3p induced, miR-196b-5p inhibited the apoptosis of Panc-1 cells via targeting NOB1 and ING5 respectively. In conclusion, we demonstrated that baicalein is a potent inhibitor against pancreatic cancer by modulating the expression of miR-139-3p or miR-196b-5p.

Ligand decorated biodegradable nanomedicine in the treatment of cancer

Cancer is one of the major global health problems, responsible for the second-highest number of deaths. The genetic and epigenetic changes in the oncogenes or tumor suppressor genes alter the regulatory pathways leading to its onset and progression. Conventional methods are used in appropriate combinations for the treatment. Surgery effectively treats localized tumors; however, it fails to treat metastatic tumors, leading to a spread in other organs, causing a high recurrence rate and death. Among the different strategies, the nanocarriers-based approach is highly sought for, but its nonspecific delivery can cause a profound side effect on healthy cells. Targeted nanomedicine has the advantage of targeting cancer cells specifically by interacting with the receptors overexpressed on their surface, overcoming its non-specificity to target healthy cells. Nanocarriers prepared from biodegradable and biocompatible materials are decorated with different ligands by encapsulating therapeutic or diagnostic agents or both to target cancer cells overexpressing the receptors. Scientists are now utilizing a theranostic approach to simultaneously evaluate nanocarrier bio-distribution and its effect on the treatment regime. Herein, we have summarized the recent 5-year efforts in the development of the ligands decorated biodegradable nanocarriers, as a targeted nanomedicine approach, which has been highly promising in the treatment of cancer.

Baicalein enhanced cisplatin sensitivity of gastric cancer cells by inducing cell apoptosis and autophagy via Akt/mTOR and Nrf2/Keap 1 pathway

Baicalein is a natural flavonoid with various pharmacological activities including antitumor. The synergistic anti-cancer effect of the combination of baicalein and Cisplatin (DDP) on gastric cancer (GC) has not been reported. MTT assay and colony formation assay were used to determine the inhibitory effect of the combination of baicalein and DDP on cell survival. Invasive assay was performed to test the effects of baicalein and DDP on cell invasive capability. A flow cytometric analysis was conducted to determine the apoptosis-induced effects of baicalein on GC cells, especially SGC-7901/DDP (resistant to DDP). Confocal laser microscope and real-time PCR were used to test autophagy-induced effects of baicalein on SGC-7901 and SGC-7901/DDP cells. Western blotting was performed to investigate the molecular mechanisms of baicalein inducing apoptosis and autophagy. Our study showed that baicalein could inhibit cell proliferation of MGC-803, HGC-27, SGC-7901 and SGC-7901/DDP, and the inhibitory effect was extremely enhanced when combining with DDP. Additionally, combination of baicalein and DDP suppressed the invasive capability and induced apoptosis and autophagy in both SGC-7901 and SGC-7901/DDP, and the effect was stronger than that of DDP or baicalein alone. The further molecular mechanism analysis indicated that baicalein modulated the activities of Akt/mTOR and Nrf2/Keap 1 signaling. Our study demonstrated that baicalein enhanced DDP sensitivity of SGC-7901/DDP gastric cancer cells by inducing apoptosis and autophagy via Akt/mTOR and Nrf2/Keap 1 pathway.

Baicalein: A metabolite with promising antineoplastic activity

Cancer, being a multifactorial disease has diverse presentation in different subgroups which is mainly attributed to heterogenous presentation of tumor cells. This cancer cell heterogeneity is the major reason for variable response to standard chemotherapeutic regimes owing to which high relapse rate and multi-drug resistance has increasingly been reported over the past decade. Interestingly, the research on natural compounds in combination with standard therapies have reported with interesting and promising results from the pre-clinical trials and few of which have also been tested in other phases of clinical trials. This review focusses on baicalein, an emerging anti-cancerous natural compound, its chemistry and mechanism of action. In view of promising pre-clinical this review is mainly motivated by the results observed from baicalein treatment of different cancer cell population. With the advancing scientific evidence on the anti-malignant potential of baicalein with respect to its pharmacological activities encompassing from anti-inflammatory to anti-angiogenic/anti-metastatic effects, the focus is mainly directed to understanding the precise mechanism of action of baicalein. In the process of understanding the underlying signaling cascades, the role of mitogen activated protein kinase (MAPK), mammalian target of rapamycin (mTOR), AKT serine/threonine protein kinase B (AKT), poly(ADP-ribose) polymerase (PARP), matrix metalloproteinases-2 (MMP-2), matrix metalloproteinases-9 (MMP-9) and caspase-3/-8,-9 have been highlighted as the major players for baicalein anti-malignant potential. This is also supported by the interesting pre-clinical findings which cumulatively pave the way ahead for development of baicalein as an adjunct anti-cancer treatment with chemotherapeutic agents.

Baicalein inhibits cell development, metastasis and EMT and induces apoptosis by regulating ERK signaling pathway in osteosarcoma

Background: Osteosarcoma is a highly malignant primary tumor. Baicalein has broad-spectrum anti-tumor effects. This study aimed to study the specific molecular regulatory mechanism of baicalein in anti-osteosarcoma and the possible regulatory signaling network involved.Methods: In vitro experiment, MG-63 cells treated with 0, 50, 75, and 100 μM of baicalein. Cell viability, proliferation, migration, invasion, cycle, apoptosis, and morphology were detected using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazoliumbromide (MTT), clone formation, wound healing, Transwell, flow cytometry, Hoechst staining, wound healing and microscopic observation. In addition, cycle, apoptosis and EMT-related proteins and p-ERK/ERK expression level were analyzed using western blotting. In vivo experiments were performed by BALB/c-nude mice model establishment to detect mice and tumor weight, tumor volume, positive rate and p-ERK/ERK expression when mice treated with 100 μM of baicalein.Results: Firstly, the IC₅₀ of baicalein was 67.57 μM. Then, baicalein decreased cell viability, proliferation, migration, invasion, and the expression of CDK2, Cyclin D1, Cyclin E1, Bcl-2, N-cad, Vimentin, MMP-2, MMP-9, p-ERK/ERK, while increased G1 phase numbers, apoptosis and the expression level of p21, p27, cleaved caspase 3/9, Bax, E-cad, ZO-1 in a dose-dependent manner in MG-63 cells. Also, baicalein reduced the body weight, tumor weight and volume and relative expression level of p-ERK/ERK in vivo.Conclusion: Baicalein inhibits cell development, metastasis, and EMT progress and induces cell cycle arrest and apoptosis by regulating ERK signaling pathway in osteosarcoma, and has a visible anti-osteosarcoma effect in vivo.

Hypoxic Macrophage-Derived VEGF Promotes Proliferation and Invasion of Gastric Cancer Cells

BACKGROUND

Gastric cancer (GC) is one of the most common causes of cancer death. Hypoxia is an important property of the tumor microenvironment of GC. Increasing evidence demonstrates that tumor-associated macrophages are related to the metastasis of GC, while the precise mechanism of how hypoxic macrophages affect tumor progression is still not fully understood.

AIMS

To examine whether the mediators released from hypoxic macrophages contribute to the invasion and proliferation of GC cells.

METHODS

Cell Counting Kit-8 was utilized to determine the proliferation of SGC7901 and MKN45 cells. The invasion of SGC7901 and MKN45 cells was measured by transwell invasion assay. Expression of VEGF mRNA in THP-1-derived macrophages was determined by RT-PCR, and protein level of VEGF in the culture medium was detected by ELISA.

RESULTS

The proliferation and invasion of SGC7901 and MKN45 cells were dramatically increased after treatment with conditioned medium (CM) collected from THP-1-derived macrophages under hypoxia (H-CM), and the phosphorylation of Akt and p38 in SGC7901 and MKN45 cells was also up-regulated by H-CM stimulation. Notably, blockage of PI3K-Akt or p38 MAP kinase abolished the effects of H-CM on the proliferation and invasion of SGC7901 and MKN45 cells. Furthermore, VEGF was increased in macrophages after hypoxia and administration with nintedanib, an inhibitor of VEGFR, significantly decreases the phosphorylation of Akt and p38, as well as the proliferation and invasion of SGC7901 and MKN45 cells in response to H-CM.

CONCLUSIONS

Our findings suggest that hypoxia-injured macrophages contribute to the proliferation and invasion of GC cells through the release of mediators such as VEGF.

Mechanisms Underlying Therapeutic Effects Of Traditional Chinese Medicine On Gastric Cancer

Gastric cancer (GC) is one of the most common malignant tumors in the world. It is the fourth most common cancer and has the second highest mortality rate globally. Metastasis is an important feature of gastric cancer and is the most common cause of death. Exploring the mechanism underlying the metastasis of gastric cancer and searching for new drug targets has become the focus of several studies. Traditional Chinese medicine may show promise for treatment of gastric cancer. In this review, we report the recent progress in research on the anti-metastasis activity of Chinese medicine, to facilitate clinical development of treatments for gastric cancer.

α-Hispanolol Induces Apoptosis and Suppresses Migration and Invasion of Glioblastoma Cells Likely via Downregulation of MMP-2/9 Expression and p38MAPK Attenuation

α-Hispanolol (α-H) is a labdane diterpenoid that has been shown to induce apoptosis in several human cancer cells. However, the effect of α-H in human glioblastoma cells has not been described. In the present work, we have investigated the effects of α-H on apoptosis, migration, and invasion of human glioblastoma cells with the aim of identifying the molecular targets underlying its mechanism of action. The results revealed that α-H showed significant cytotoxicity against human glioma cancer cell lines U87 and U373 in a concentration- and time-dependent manner. This effect was higher in U87 cells and linked to apoptosis, as revealed the increased percentage of sub-G₁ population by cell cycle analysis and acquisition of typical features of apoptotic cell morphology. Apoptosis was also confirmed by significant presence of annexin V-positive cells and caspase activation. Pretreatment with caspase inhibitors diminishes the activities of caspase 8, 9, and 3 and maintains the percentage of viable glioblastoma cells, indicating that α-H induced cell apoptosis through both the extrinsic and the intrinsic pathways. Moreover, we also found that α-H downregulated the anti-apoptotic Bcl-2 and Bcl-xL proteins and activated the pro-apoptotic Bid and Bax proteins. On the other hand, α-H exhibited inhibitory effects on the migration and invasion of U87 cells in a concentration-dependent manner. Furthermore, additional experiments showed that α-H treatment reduced the enzymatic activities and protein levels of matrix metalloproteinase MMP-2 and MMP-9 and increased the expression of TIMP-1 inhibitor, probably via p38MAPK regulation. Finally, xenograft assays confirmed the anti-glioma efficacy of α-H. Taken together, these findings suggest that α-H may exert anti-tumoral effects in vitro and in vivo through the inhibition of cell proliferation and invasion as well as by the induction of apoptosis in human glioblastoma cells. This research describes α-H as a new drug that may improve the therapeutic efficacy against glioblastoma tumors.

Oxymatrine inhibits the migration and invasion of hepatocellular carcinoma cells by reducing the activity of MMP-2/-9 via regulating p38 signaling pathway

As one of the major alkaloid components in Sophoraflavescensait (kushen), oxymatrine has been used widely across the world in anti-inflammatory and anti-cancer therapies. However, the effect in the metastasis of hepatocellular carcinoma (HCC) and related mechanism(s) are still unclear. The present study aimed to investigate the anti-metastatic effect of oxymatrine on HCC cells. Oxymatrine could also inhibit the protein levels of MMP-2/-9 in a dose-dependent relationship. Moreover, oxymatrine reduces the activity of p38 signaling pathway via inhibiting the phosphorylation of p38. The inhibition effect of oxymatrine on the expression of MMP-2/-9 and the phosphorylated of p38 was also detected in vivo. Combined treatment with p38 signaling pathway inhibitor and oxymatrine may have a synergistic effect on MMP-2/-9 and invasion of HCC cells. Therefore, oxymatrine may have inhibited GBC invasiveness by reducing the expression of MMP-2/-9 via inhibiting the activity of p38 signaling pathway. As a potentially novel therapeutic drug, oxymatrine may play an important role in the treatment of HCC.

Traditional Chinese medicine-combination therapies utilizing nanotechnology-based targeted delivery systems: a new strategy for antitumor treatment

Cancer is a major public health problem, and is now the world’s leading cause of death. Traditional Chinese medicine (TCM)-combination therapy is a new treatment approach and a vital therapeutic strategy for cancer, as it exhibits promising antitumor potential. Nano-targeted drug-delivery systems have remarkable advantages and allow the development of TCM-combination therapies by systematically controlling drug release and delivering drugs to solid tumors. In this review, the anticancer activity of TCM compounds is introduced. The combined use of TCM for antitumor treatment is analyzed and summarized. These combination therapies, using a single nanocarrier system, namely codelivery, are analyzed, issues that require attention are determined, and future perspectives are identified. We carried out a systematic review of >280 studies published in PubMed since 1985 (no patents involved), in order to provide a few basic considerations in terms of the design principles and management of targeted nanotechnology-based TCM-combination therapies.

Effect of Baicalein on Matrix Metalloproteinases and Durability of Resin-Dentin Bonding

OBJECTIVE

In an attempt to increase resin-dentin bonding quality, this study used baicalein as a preconditioner in an etch-and-rinse adhesive to evaluate its effect on matrix metalloproteinases (MMPs) and adhesive durability.

METHODS

As a MMP inhibitor and potential collagen cross-linking agent, baicalein was used as a preconditioner in an etch-and-rinse adhesive system. The degree of conversion was evaluated by Fourier-transform infrared spectroscopy. EnzChek gelatinase/collagenase assay kits were then used to detect the MMP inhibitory effect of different concentrations of baicalein (0.1, 0.5, 2.5, and 5.0 μg/mL) on dentin powders. During in vitro bonding procedures, flat dentin surfaces on sound third molars were preconditioned with 2.5 μg/mL baicalein after being acid-etched; this step was followed by continuation of adhesive processes and build-up of resin composite. After resin-dentin stick preparation, bonding strength, failure mode, and interface nanoleakage were respectively evaluated via microtensile testing, stereomicroscopy, and field emission scanning electron microscopy either immediately or after storage in artificial saliva for three or six months. Data were analyzed by two-way analysis of variance and Tukey test (α=0.05).

RESULTS

Baicalein at a concentration of 0-5.0 μg/mL did not influence the conversion of adhesives. However, it inhibited the activities of dentin-bond gelatinase and collagenase, especially at a concentration of 2.5 μg/mL, while effectively increasing microtensile bonding strength and decreasing nanoleakage in vitro, both immediately and after aging.

CONCLUSIONS

Baicalein used as preconditioner in an etch-and-rinse adhesive system has an anti-MMP function and effectively improves resin-dentin bonding durability in vitro, which has potential value in clinical bonding procedures.

Baicalein inhibits cell growth and increases cisplatin sensitivity of A549 and H460 cells via miR-424-3p and targeting PTEN/PI3K/Akt pathway

Lung cancer is the leading cause of death in individuals with malignant disease. Non‐small‐cell lung cancer (NSCLC) is the most common type of lung cancer, and chemotherapy drugs such as cisplatin are the most widely used treatment for this disease. Baicalein is a purified flavonoid compound that has been reported to inhibit cancer cell growth and metastasis and increase sensitization to chemotherapeutic drugs via different pathways. Therefore, we assessed the effects of baicalein on the proliferation, apoptosis and cisplatin sensitivity in the NSCLC A549 and H460 cell lines and determined the pathways through which baicalein exerts its effects. Baicalein was slightly toxic to normal human bronchial NHBE cells but inhibited growth, induced apoptosis and increased cisplatin sensitivity in A549 and H460 cells. Baicalein down‐regulated miR‐424‐3p, up‐regulated PTEN expression and down‐regulated expression of PI3K and p‐Akt in A549 and H460 cells. Dual‐luciferase reporter assay demonstrated that PTEN is a target gene of miR‐424‐3p, and overexpression of miR‐424‐3p or silencing of PTEN partially attenuated the effects of baicalein on A549 and H460 cells. Taken together, we concluded that baicalein inhibits cell growth and increases cisplatin sensitivity to A549 and H460 cells via down‐regulation of miR‐424‐3p and targeting the PTEN/PI3K/Akt pathway.

Asparaginyl endopeptidase promotes the invasion and metastasis of gastric cancer through modulating epithelial-to-mesenchymal transition and analysis of their phosphorylation signaling pathways

Asparaginyl endopeptidase (AEP) is a lysosomal protease often overexpressed in gastric cancer. AEP was expressed higher in peritoneal metastatic loci than in primary gastric cancer. Then we overexpressed AEP or knocked it down with a lentiviral vector in gastric cancer cell lines and detected the cell cycle arrest and the changes of the invasive and metastatic ability in vitro and in vivo. When AEP was knocked-down, the proliferative, invasive and metastatic capacity of gastric cancer cells were inhibited, and the population of sub-G1 cells increased. AEP knockdown led to significant decrease of expression of transcription factor Twist and the mesenchymal markers N-cadherin, ß-catenin and Vimentin and to increased expression of epithelial marker E-cadherin. These results showed that AEP could promote invasion and metastasis by modulating EMT. We used phosphorylation-specific antibody microarrays to investigate the mechanism how AEP promotes gastric cancer invasion and metastasis, and found that the phosphorylation level of AKT and MAPK signaling pathways was decreased significantly if AEP was knocked-down. Therefore, AKT and MAPK signaling pathways took part in the modulation.

Baicalein Inhibits the Proliferation of Cervical Cancer Cells Through the GSK3β-Dependent Pathway

Baicalein, a flavonoid derived from the root of Scutellaria baicalensis, has been reported to possess multiple pharmacological activities, such as anticancer and anti-inflammatory properties. This study investigated the effect of baicalein in cervical cancer cells. Cell growth curve and MTT assay were performed and revealed that baicalein inhibited the proliferation of SiHa and HeLa cells in a dose-dependent manner. We further found that baicalein arrested the cell cycle of SiHa and HeLa cells at the G₀/G₁ phase by suppressing the expression of cyclin D1 through the downregulation of phosphorylated protein kinase B (p-AKT) and phosphorylated glycogen synthase kinase 3β (p-GSK3β) according to FACS assays and Western blotting. Moreover, when CHIR-99021, a GSK3β inhibitor, was added to baicalein-treated SiHa cells, the expression of cyclin D1 was recovered, and cell proliferation was promoted. In conclusion, these data indicated that baicalein suspended the cell cycle at the G₀/G₁ phase via the downregulation of cyclin D1 through the AKT–GSK3β signaling pathway and further inhibited the proliferation of SiHa and HeLa cervical cancer cells.

Assessment of Hepatocellular Carcinoma Metastasis Glycobiomarkers Using Advanced Quantitative N-glycoproteome Analysis

Hepatocelluar carcinoma (HCC) is one of the most common malignant tumors with high incidence of metastasis. Glycosylation is involved in fundamental molecular and cell biology process occurring in cancer including metastasis formation. In this study, lectin microarray, lectin blotting, lectin affinity chromatography and tandem ¹⁸O stable isotope labeling coupled with liquid chromatography-mass spectrometer (LC-MS) analysis were applied to quantify the changes in N-glycosite occupancy for HCC metastasis serum. Firstly, lectin microarray was used to screen glycoforms and Phaseolus vulgaris Leucoagglutinin (PHA-L) reactive structure (β1,6-GlcNAc branched N-glycan) was found to be increased significantly in HCC patients with metastasis compared with those with non-metastasis. Then, PHA-L affinity glycoproteins were enriched followed by N-glycosite occupancy measurement with strategy of tandem ¹⁸O stable isotope labeling. 11 glycoproteins with significantly changed N-glycosite occupancy were identified, they were associated with cell migration, invasion and adhesion through p38 mitogen-activated protein kinase signaling pathway and nuclear factor kappa B signaling pathway. Quantification of N-glycosite occupancy for PHA-L reactive glycoproteins could help to discover important glycoproteins of potential clinically significance in terms of HCC etiology. Also, understanding of N-glycosite occupancy alterations will aid the characterization of molecular mechanism of HCC metastasis as well as establishment of novel glycobiomarkers.

The Fascinating Effects of Baicalein on Cancer: A Review

Cancer is one of the leading causes of death worldwide and a major global health problem. In recent decades, the rates of both mortality and morbidity of cancer have rapidly increased for a variety of reasons. Despite treatment options, there are serious side effects associated with chemotherapy drugs and multiple forms of drug resistance that significantly reduce their effects. There is an accumulating amount of evidence on the pharmacological activities of baicalein (e.g., anti-inflammatory, antioxidant, antiviral, and antitumor effects). Furthermore, there has been great progress in elucidating the target mechanisms and signaling pathways of baicalein's anti-cancer potential. The anti-tumor functions of baicalein are mainly due to its capacities to inhibit complexes of cyclins to regulate the cell cycle, to scavenge oxidative radicals, to attenuate mitogen activated protein kinase (MAPK), protein kinase B (Akt) or mammalian target of rapamycin (mTOR) activities, to induce apoptosis by activating caspase-9/-3 and to inhibit tumorinvasion and metastasis by reducing the expression of matrix metalloproteinase-2/-9 (MMP-2/-9). In this review, we focused on the relevant biological mechanisms of baicalein involved in inhibiting various cancers, such as bladder cancer, breast cancer, and ovarian cancer. Moreover, we also summarized the specific mechanisms by which baicalein inhibited the growth of various tumors in vivo. Taken together, baicalein may be developed as a potential, novel anticancer drug to treat tumors.

Anticancer properties of baicalein: a review

The constituents of many traditional Chinese herbal remedies are currently at the forefront of modern cancer research. Baicalein, a bioactive flavone widely used in nutraceuticals and pharmaceuticals, has shown great potential in the treatment and prevention of cancer without causing severe side effects. Baicalein induces cancer cell apoptosis and cause cell cycle arrest. It shows inhibitory effects on angiogenesis, metastasis and inflammation, all of which are necessary for the promotion and progression of cancer. This review presents an overview of the anti-cancer effects and mechanisms of baicalein. In addition, the bioavailability of baicalein and approaches to improve it are summarized. Treatments of baicalein in combination with other anti-cancer agents are also mentioned.

Baicalein suppresses metastasis of breast cancer cells by inhibiting EMT via downregulation of SATB1 and Wnt/β-catenin pathway

BACKGROUND

The flavonoid baicalein, a historically used Chinese herbal medicine, shows a wide range of biological and pharmaceutical effects, among which its potent antitumor activity has raised great interest in recent years. However, the molecular mechanism involved in the antimetastatic effect of baicalein remains poorly understood. This study aimed to verify the inhibitory effects of baicalein on metastasis of MDA-MB-231 human breast cancer cells both in vitro and in vivo, as well as to investigate the related mechanisms.

METHODS

MTT assay was used to examine the inhibition of baicalein on proliferation of MDA-MB-231 cells. Wound healing assay and the in vitro invasion assay was carried out to investigate the effects of baicalein on migration and invasion of MDA-MB-231 cells, respectively. In order to explore the effects of baicalein on tumor metastasis in vivo, xenograft nude mouse model of MDA-MB-231 cells was established. Animals were randomly divided into four groups (control, therapy group, and low-dose and high-dose prevention group, n=6), and treated with baicalein as designed. Following sacrifice, their lungs and livers were collected to examine the presence of metastases. qRT-PCR and Western blot were performed to study the effects of baicalein on expression of SATB1, EMT-related molecules, and Wnt/β-catenin signaling components of MDA-MB-231 cells as well as the metastatic tissue. Effects of baicalein on the expression of target proteins in vivo were also analyzed by immunohistochemistry.

RESULTS

Our results indicated that baicalein suppressed proliferation, migration, and invasion of MDA-MB-231 cells in a time- and dose-dependent manner. Based on assays carried out in xenograft nude mouse model, we found that baicalein inhibited tumor metastasis in vivo. Furthermore, baicalein significantly decreased the expression of SATB1 in MDA-MB-231 cells. It suppressed the expression of vimentin and SNAIL while enhancing the expression of E-cadherin. Baicalein also downregulated the expression of Wnt1 and β-catenin proteins and transcription level of Wnt/β-catenin-targeted genes.

CONCLUSION

Our results demonstrate that baicalein has the potential to suppress breast cancer metastasis, possibly by inhibition of EMT, which may be attributed to downregulation of both SATB1 and the Wnt/β-catenin pathway. Taken together, baicalein may serve as a promising drug for metastasis treatment of breast cancer.

Mitogen-activated protein kinase signaling pathway and invasion and metastasis of gastric cancer

The mortality rate of gastric cancer worldwide is as high as 70%, despite the development of novel therapeutic strategies. One reason for the high mortality is the rapid and uninhibited spread of the disease, such that the majority of patients are diagnosed at a stage when efficient therapeutic treatment is not available. Therefore, in-depth research is needed to investigate the mechanism of gastric cancer metastasis and invasion to improve outcomes and provide biomarkers for early diagnosis. The mitogen-activated protein kinase (MAPK) signaling pathway is widely expressed in multicellular organisms, with critical roles in multiple biological processes, such as cell proliferation, death, differentiation, migration, and invasion. The MAPK pathway typically responds to extracellular stimulation. However, the MAPK pathway is often involved in the occurrence and progression of cancer when abnormally regulated. Many studies have researched the relationship between the MAPK signaling pathway and cancer metastasis and invasion, but little is known about the important roles that the MAPK signaling pathway plays in gastric cancer. Based on an analysis of published data, this review aims to summarize the important role that the MAP kinases play in the invasion and metastasis of gastric cancer and attempts to provide potential directions for further research and clinical treatment.