Bufalin inhibits migration and invasion in human hepatocellular carcinoma SK-Hep1 cells through the inhibitions of NF-kB and matrix metalloproteinase-2/-9-signaling pathways

A review on animal venom-based matrix metalloproteinase modulators and their therapeutic implications

Matrix Metalloproteinases (MMPs) belong to a family of proteolytic enzymes that degrade extracellular matrix components, such as collagen, elastin, laminin, and fibronectin. They also play a part in tissue remodeling by cleaving and rejoining the tissue proteins. Cancer, neurodegenerative disorders, cardiovascular diseases, arthritis, and chronic inflammatory conditions are just some of the diseases that can start or get worse when different MMPs are not working properly. Venomous Animals such as honeybees, toads, snakes, spiders, scorpions, jellyfish, and sea anemones contain venom-secreting glands, which help them defend against predators and immobilize their prey. The molecules that come from animal venom are a complicated mix of bioactive molecules, such as peptides, enzymes, proteins, and small organic compounds that do a number of biological things. Venom-derived molecules have been found to modulate MMP. These venoms and their components target specific signaling pathways, modifying MMP expression levels to either induce inflammation or exhibit anti-inflammatory effects. In this review, we study and explore different MMPs, such as MMP1, MMP2, MMP3, MMP7, MMP8, and MMP9, and their roles in the progression of certain diseases. We also look at different types of molecules derived from marine and land animal venom that are used as MMP modulators. We look at how they work by targeting specific signaling pathways to change MMPs and how they might be used as a medicine to stop diseases by decreasing MMPs.

The advancement of structure, bioactivity, mechanism, and synthesis of bufotalin

Toad venom, a family of toxic yet pharmacologically valuable biotoxins, has long been utilized in traditional medicine and holds significant promise in modern drug development. Bufotalin, a prominent bufotoxin, has demonstrated potent cytotoxic properties through mechanisms such as apoptosis induction, cell cycle arrest, endoplasmic reticulum stress activation, and inhibition of metastasis by modulating key pathways including Akt, p53, and STAT3/EMT signaling-these multi-target mechanisms position bufotalin as a promising agent to combat multidrug resistance in cancer therapy. Additionally, advances in bufotalin synthesis, including chemical and biocatalytic methods, have streamlined production, with strategies such as C14α-hydroxylation and novel coupling techniques enhancing yield and reducing environmental impact. This review consolidates recent progress on bufotalin's structure, activity, cytotoxic mechanisms, and synthetic methodologies, offering a foundation for further development as an innovative chemotherapy agent.

Bufalin Suppresses Head and Neck Cancer Development by Modulating Immune Responses and Targeting the β-Catenin Signaling Pathway

Bufalin, a cardiotonic steroid derived from the Chinese toad (Bufo gargarizans), has demonstrated potent anticancer properties across various cancer types, positioning it as a promising therapeutic candidate. However, comprehensive mechanistic studies specific to head and neck cancers have been lacking. Our study aimed to bridge this gap by investigating bufalin's mechanisms of action in head and neck cancer cells. Using several methods, such as Western blotting, immunofluorescence, and flow cytometry, we observed bufalin's dose-dependent reduction in cell viability, disruption of cell membrane integrity, and inhibition of colony formation in both HPV-positive and HPV-negative cell lines. Bufalin induces apoptosis through the modulation of apoptosis-related proteins, mitochondrial function, and reactive oxygen species production. It also arrests the cell cycle at the G2/M phase and attenuates cell migration while affecting epithelial-mesenchymal transition markers and targeting pivotal signaling pathways, including Wnt/β-catenin, EGFR, and NF-κB. Additionally, bufalin exerted immunomodulatory effects by polarizing macrophages toward the M1 phenotype, bolstering antitumor immune responses. These findings underscore bufalin's potential as a multifaceted therapeutic agent against head and neck cancers, targeting essential pathways involved in proliferation, apoptosis, cell cycle regulation, metastasis, and immune modulation. Further research is warranted to validate these mechanisms and optimize bufalin's clinical application.

Influence of Different Ratios of DSPE-PEG2k on Ester Prodrug Self-Assembly Nanoparticles for Cell Migration and Proliferation Suppression

Background

Bufalin (BFL, an active anti-tumor compound derived from toad venom) is limited in its application due to high toxicity and rapid metabolism of the cardiotonic steroid. Ester prodrug self-assembly nanoparticles have shown significant improved effects in addressing the above-mentioned issues.

Methods

An ester bond was formed between linoleic acid and bufalin to synthesize linoleic acid-bufalin prodrug (LeB). The self-assembly nanoparticles (LeB-PSNs) containing different mass ratios of DSPE-PEG2k and prodrug (6:4, 7:3, 8:2, 9:1 and 10:0) were prepared via co-precipitation method and defined as 6:4-PSNs, 7:3-PSNs, 8:2-PSNs, 9:1-PSNs and LeB-PSNs, respectively. Further, the characterization (particle size, zeta potential, surface morphology and stability) of the nanoparticles was carried out. Finally, we evaluated the impact of different ratios of DSPE-PEG2k on the hydrolysis rate, cytotoxicity, cellular uptake, cell migration and proliferation suppression potential of the prodrug nanoparticles.

Results

The linoleic acid-bufalin prodrug (LeB) was successfully synthesized. Upon the addition of DSPE-PEG2k at different weight ratios, both particle size and polydispersity index (PDI) significantly decreased, while the zeta potential increased remarkably. No significant differences in particle size, PDI and Zeta potential were observed among the 9:1, 8:2 and 7:3 PSNs. Notably, the 8:2 (w/w) DSPE-PEG2k nanoparticles exhibited superior stability, hydrolysis and cellular uptake rates, along with efficient cell cytotoxicity, cell migration and proliferation suppression.

Conclusion

These findings indicate that DSPE-PEG2k could improve the performance of BFL prodrug nanoparticles, namely enhancing stability and achieving adaptive drug release by modulating the hydrolysis rate of esterase. This study therefore provides more opportunities for the development of BFL application.

CCL3-CCR5 axis promotes cell migration and invasion of colon adenocarcinoma via Akt signaling pathway

BACKGROUND

Infiltration of tumor-associated macrophages (TAMs) can promote tumorigenesis and development. C-C motif chemokine ligand 3 (CCL3) was reported to be derived from TAMs and tumor cells and facilitate the progression of several cancers. Nevertheless, whether CCL3 can be derived from TAMs and tumor cells of colon adenocarcinoma (COAD) is unclarified.

METHODS

Peripheral blood monocytes-derived macrophages were polarized by the conditioned medium from COAD cells to establish TAM-like macrophages (TAM1/2). RT-qPCR and western blotting were used for detection of expression levels of CCL3 and its receptors C-C motif chemokine receptor 1 (CCR1) and CCR5 in TAM1/2 and COAD cells. Immunofluorescence staining was utilized for evaluating CCL3, CD163 and CCR5 expression. The Akt signaling pathway-associated protein levels were measured by western blotting. Transwell assays were used for assessing cell migration and invasiveness.

RESULTS

CCL3 displayed a high level in TAMs and cancer cells of COAD. CCL3 activated the Akt signaling pathway by binding to CCR5. CCL3-CCR5 axis facilitated COAD cell migration and invasiveness by activating the Akt signaling. CCL3 derived from both TAMs and cancer cells contributed to the malignant behaviors of COAD cells. High expression of CCL3/CCR5 was closely associated with poor prognoses of COAD patients.

CONCLUSION

CCL3-CCR5 interaction promotes cell migration and invasiveness, and functions as a prognostic biomarker for COAD.

Bufadienolides originated from toad source and their anti-inflammatory activity

Bufadienolide, an essential member of the C-24 steroid family, is characterized by an α-pyrone positioned at C-17. As the predominantly active constituent in traditional Chinese medicine of Chansu, bufadienolide has been prescribed in the treatment of numerous ailments. It is a specifically potent inhibitor of Na+/K+ ATPase with excellent anti-inflammatory activity. However, the severe side effects triggered by unbiased inhibition of the whole-body cells distributed α1-subtype of Na+/K+ ATPase, restrict its future applicability. Thus, researchers have paved the road for the structural alteration of desirable bufadienolide derivatives with minimal adverse effects via biotransformation. In this review, we give priority to the present evidence for structural diversity, MS fragmentation principles, anti-inflammatory efficacy, and structure modification of bufadienolides derived from toads to offer a scientific foundation for future in-depth investigations and views.

Bufalin for an innovative therapeutic approach against cancer

Bufalin is an endogenous cardiotonic steroid, first discovered in toad venom but also found in the plasma of healthy humans, with anti-tumour activities in different cancer types. The current review is focused on its mechanisms of action and highlights its very large spectrum of effects both in vitro and in vivo. All leads to the conclusion that bufalin mediates its effects by affecting all the hallmarks of cancer and seems restricted to cancer cells avoiding side effects. Bufalin decreases cancer cell proliferation by acting on the cell cycle and inducing different mechanisms of cell death including apoptosis, necroptosis, autophagy and senescence. Bufalin also moderates metastasis formation by blocking migration and invasion as well as angiogenesis and by inducing a phenotype switch towards differentiation and decreasing cancer cell stemness. Regarding its various mechanisms of action in cancer cells, bufalin blocks overactivated signalling pathways and modifies cell metabolism. Moreover, bufalin gained lately a huge interest in the field of drug resistance by both reversing various drug resistance mechanisms and affecting the immune microenvironment. Together, these data support bufalin as a quite promising new anti-cancer drug candidate.

The Research Progress of Bufalin in the Treatment of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the deadliest cancers in the world with a five-year survival rate of less than 20%. Nonetheless, selecting an appropriate therapeutic agent to inhibit the development of hepatoma cells is still a challenge. Bufalin, a component of the traditional Chinese medicine Chansu, has been shown to inhibit the proliferation, invasion and metastasis of HCC through various signaling pathways. In addition, bufalin and sorafenib demonstrate a synergistic effect in cancer therapeutics. This review highlighted on several focal signaling pathways involved in the inhibitory effects of bufalin on HCC and its synergistic mechanisms with sorafenib. The immunotherapy effect of bufalin has also been discussed as a novel property.

Screening of Bufadienolides from Toad Venom Identifies Gammabufotalin as a Potential Anti-inflammatory Agent

Toad venom (Chansu) is used in the treatment of infectious and inflammatory diseases in China and East/Southeast Asian countries. However, the anti-inflammatory components of toad venom have not yet been systematically evaluated and clearly defined. To investigate the anti-inflammatory effects of toad venom and identify new anti-inflammatory ingredients, we used zebrafish, an alternative drug screening model, to evaluate the anti-inflammatory effects of 14 bufadienolides previously isolated from toad venom. Most of the bufadienolides were found to exert significant anti-inflammatory effects on lipopolysaccharide-, CuSO₄-, or tail transection-induced zebrafish inflammatory models. Moreover, gammabufotalin ( 6: ) inhibits lipopolysaccharide-induced inflammation by suppressing the myeloid differentiation primary response 88/nuclear factor-kappa B and STAT3 signal pathways. This study confirms the potential of zebrafish in drug screening, clarifies the anti-inflammatory effects of bufadienolides from toad venom, and indicates that gammabufotalin may be developed as a novel therapeutic agent for inflammatory diseases in the future.

Novel Strategies for Solubility and Bioavailability Enhancement of Bufadienolides

Toad venom contains a large number of bufadienolides, which have a variety of pharmacological activities, including antitumor, cardiovascular, anti-inflammatory, analgesic and immunomodulatory effects. The strong antitumor effect of bufadienolides has attracted considerable attention in recent years, but the clinical application of bufadienolides is limited due to their low solubility and poor bioavailability. In order to overcome these shortcomings, many strategies have been explored, such as structural modification, solid dispersion, cyclodextrin inclusion, microemulsion and nanodrug delivery systems, etc. In this review, we have tried to summarize the pharmacological activities and structure-activity relationship of bufadienolides. Furthermore, the strategies for solubility and bioavailability enhancement of bufadienolides also are discussed. This review can provide a basis for further study on bufadienolides.

Revealing the suppressive role of protein kinase C delta and p38 mitogen-activated protein kinase (MAPK)/NF-κB axis associates with lenvatinib-inhibited progression in hepatocellular carcinoma in vitro and in vivo

Nuclear factor-kappa B (NF-κB), an oncogenic transcription factor, modulates tumor formation and progression by inducing the expression of oncogenes involved in proliferation, survival, angiogenesis, and metastasis. Oral multikinase inhibitors, such as sorafenib, regorafenib, and lenvatinib have been used for the treatment of hepatocellular carcinoma (HCC). Both sorafenib and regorafenib were shown to abolish the NF-κB-mediated progression of HCC. However, the effect of lenvatinib on NF-κB-mediated progression of HCC is ambiguous. Therefore, the primary purpose of the present study was to evaluate the inhibitory effect of lenvatinib and its inhibitory mechanism on the NF-κB-mediated progression of HCC in vitro and in vivo. Here, we used two HCC cell lines to identify the cytotoxicity, apoptosis and metastasis effect of lenvatinib. We also applied a Hep3B-bearing animal model to investigate the therapeutic efficacy of lenvatinib on in vivo model. An NF-κB translocation assay, NF-κB reporter gene assay, a Western blotting assay and immunohistochemistry staining were used to investigate the underlying mechanism by which lenvatinib acts on HCC. In this study, we demonstrated that lenvatinib induced extrinsic/intrinsic apoptosis and suppressed the metastasis of HCC both in vitro and in vivo. Lenvatinib may also suppress NF-κB translocation and activation. We also found both protein kinase C delta (PKC-δ) and p38 mitogen-activated protein kinase (MAPK) inactivation participated in lenvatinib-reduced NF-κB signaling. In conclusion, this study reveals that the suppression of PKC-δ, and the p38 MAPK/NF-κB axis is associated with the lenvatinib-inhibited progression of HCC in vitro and in vivo.

Inhibition of matrix stiffness relating integrin β1 signaling pathway inhibits tumor growth in vitro and in hepatocellular cancer xenografts

Background

Cancer development is strictly correlated to composition and physical properties of the extracellular matrix. Particularly, a higher matrix stiffness has been demonstrated to promote tumor sustained growth. Our purpose was to explore the role of matrix stiffness in liver cancer development.

Methods

The matrix stiffness of tumor tissues was determined by atomic force microscopy (AFM) analysis. In vitro, we used a tunable Polyacrylamide (PA) hydrogels culture system for liver cancer cells culture. The expression level of integrin β1, phosphorylated FAK, ERK1/2, and NF-κB in SMMC-7721 cells was measured by western blotting analysis. We performed MTT, colony formation and transwell assay to examine the tumorigenic and metastatic potential of SMMC-7721 cells cultured on the tunable PA hydrogels. SMMC-7721 cancer xenografts were established to explore the anticancer effects of integrin inhibitors.

Results

Our study provided evidence that liver tumor tissues from metastatic patients possessed a higher matrix stiffness, when compared to the non-metastatic group. Liver cancer cells cultured on high stiffness PA hydrogels displayed enhanced tumorigenic potential and migrative properties. Mechanistically, activation of integrin β1/FAK/ ERK1/2/NF-κB signaling pathway was observed in SMMC-7721 cells cultured on high stiffness PA hydrogels. Inhibition of ERK1/2, FAK, and NF-κB signaling suppressed the pro-tumor effects induced by matrix stiffness. Combination of chemotherapy and integrin β1 inhibitor suppressed the tumor growth and prolonged survival time in hepatocellular cancer xenografts.

Conclusion

A higher matrix stiffness equipped tumor cells with enhanced stemness and proliferative characteristics, which was dependent on the activation of integrin β1/FAK/ERK1/2/NF-κB signaling pathway. Blockade of integrin signals efficiently improved the outcome of chemotherapy, which described an innovative approach for liver cancer treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08982-3.

Therapeutic potential of targeting membrane-spanning proteoglycan SDC4 in hepatocellular carcinoma

Syndecan-4 (SDC4) functions as a major endogenous membrane-associated receptor and widely regulates cytoskeleton, cell adhesion, and cell migration in human tumorigenesis and development, which represents a charming anti-cancer therapeutic target. Here, SDC4 was identified as a direct cellular target of small-molecule bufalin with anti-hepatocellular carcinoma (HCC) activity. Mechanism studies revealed that bufalin directly bond to SDC4 and selectively increased SDC4 interaction with substrate protein DEAD-box helicase 23 (DDX23) to induce HCC genomic instability. Meanwhile, pharmacological promotion of SDC4/DDX23 complex formation also inactivated matrix metalloproteinases (MMPs) and augmented p38/JNK MAPKs phosphorylation, which are highly associated with HCC proliferation and migration. Notably, specific knockdown of SDC4 or DDX23 markedly abolished bufalin-dependent inhibition of HCC proliferation and migration, indicating SDC4/DDX23 signaling axis is highly involved in the HCC process. Our results indicate that membrane-spanning proteoglycan SDC4 is a promising druggable target for HCC, and pharmacological regulation of SDC4/DDX23 signaling axis with small-molecule holds great potential to benefit HCC patients.

Tumor-Targeted Delivery of Bufalin-Loaded Modified Albumin-Polymer Hybrid for Enhanced Antitumor Therapy and Attenuated Hemolysis Toxicity and Cardiotoxicity

A novel albumin polymer hybrid with a core-shell structure was designed to target delivery of bufalin, which is an antineoplastic monomer with serious cardiotoxicity. The sheath layer was composed of ursodeoxycholic acid (UA)-modified bovine serum albumin (UA-BSA), while the stable core consisted of poly n-butyl cyanoacrylate (PBCA) nanoparticles. The UA-BSA was synthetized, and the substitution degree was characterized. The physical properties of bufalin-loaded UA-modified protein-PBCA nanocomplexes (BF-uPPNCs), such as morphology, particle size, and encapsulation efficiency, were evaluated. FTIR and DSC revealed the bufalin to be in an amorphous state. Furthermore, the in vitro release study indicated a sustained release profile of BF-uPPNCs. The MTT and cellular uptake study demonstrated that BF-uPPNCs significantly improved the inhibitory effect of the bufalin accompanied with an enhanced cell uptake capacity on HepG2 cells. In addition, in vivo research demonstrated that BF-uPPNCs had a better antitumor effect coupled with improved therapeutic effect, and reduced hemolysis, vascular irritation, and cardiotoxicity. This work therefore presented a novel albumin polymer hybrid with favorable stability, efficient tumor-targeted delivery potential, and side effect reduction ability, which can be a potential vehicle for an anticancer drug.

The Role of Chronic Inflammation in Various Diseases and Anti-inflammatory Therapies Containing Natural Products

Chronic inflammation represents a long-term reaction of the body's immune system to noxious stimuli. Such a sustained inflammatory response sometimes results in lasting damage to healthy tissues and organs. In fact, chronic inflammation is implicated in the development and progression of various diseases, including cardiovascular diseases, respiratory diseases, metabolic diseases, neurodegenerative diseases, and even cancers. Targeting nonresolving inflammation thus provides new opportunities for treating relevant diseases. In this review, we will go over several chronic inflammation-associated diseases first with emphasis on the role of inflammation in their pathogenesis. Then, we will summarize a number of natural products that exhibit therapeutic effects against those diseases by acting on different markers in the inflammatory response. We envision that natural products will remain a rich resource for the discovery of new drugs treating diseases associated with chronic inflammation.

Bufalin: A Systematic Review of Research Hotspots and Antitumor Mechanisms by Text Mining and Bioinformatics

Bufalin is an anticancer drug extract from traditional Chinese medicine. Several articles about bufalin have been published. However, the literature on bufalin has not yet been systematically studied. This study aimed to identify the study status and knowledge structures of bufalin and to summarize the antitumor mechanism. Data were retrieved and downloaded from the PubMed database. The softwares of BICOMB, gCLUTO, Ucinet 6.0, and NetDraw2.084 were used to analyze these publications. The bufalin related genes were recognized and tagged by ABNER software. Then these BF-related genes were performed by Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis, and protein-protein interaction (PPI) network analysis. A total of 474 papers met the search criteria from 2000 to 2019. By biclustering clustering analysis, the 50 high-frequency main MeSH terms/subheadings were classified into 5 clusters. The clusters of drug therapy and the mechanism of bufalin were hotspot topics. A total of 50 genes were identified as BF-related genes. PPI network analysis showed that inducing apoptosis was the main effect of bufalin, and apoptosis-related gene Caspase 3 was the most reported by people. Bufalin could inhibit the proliferation, invasion, and metastasis of cancer cells through multiple signaling pathways, such as PI3K/AKT, Hedgehog, MAPK/JNK, Wnt/[Formula: see text]-catenin, TGF-[Formula: see text]/Smad, Integrin signaling pathway, and NF-KB signaling pathway via KEGG analysis. Through the quantitative analysis of bufalin literature, we revealed the research status and hot spots in this field and provided some guidance for further research.

Glycyrrhizic Acid Modulates Apoptosis through Extrinsic/Intrinsic Pathways and Inhibits Protein Kinase B- and Extracellular Signal-Regulated Kinase-Mediated Metastatic Potential in Hepatocellular Carcinoma In Vitro and In Vivo

A previous study presented that glycyrrhizic acid as the hepatoprotective agent inhibits total parenteral nutrition-associated acute liver injury in rats. However, the anticancer effect and mechanism of glycyrrhizic acid in human hepatocellular carcinoma (HCC) is ambiguous. The purpose of the present study was to investigate the effect of glycyrrhizic acid on apoptosis dysregulation and metastatic potential in HCC in vitro and in vivo. Both SK-Hep1 and Hep3B cells were treated with different concentrations of glycyrrhizic acid for 24 or 48h. SK-Hep1/luc2 tumor-bearing mice were treated with vehicle or glycyrrhizic acid (50mg/kg/day by intraperitoneal injection) for 7 days. Tumor cells growth, apoptotic, and metastatic signaling transduction were evaluated by using MTT assay, digital caliper, bioluminescence imaging (BLI), flow cytometry, western blotting assay, and immunohistochemistry (IHC) staining. The results demonstrated glycyrrhizic acid significantly inhibits tumor cell growth, cell invasion, and expression of AKT (Ser473), extracellular-signal-regulated kinase (ERK), epidermal growth factor receptor (EGFR) phosphorylation, anti-apoptotic and metastatic proteins in HCC in vitro and in vivo. Glycyrrhizic acid also significantly triggered apoptosis and extrinsic/intrinsic apoptotic signaling transduction. In addition, PD98059 (ERK inhibitor) and LY294002 (AKT inhibitor) obviously reduced cell invasion and expression of metastasis-associated proteins. Taken together, these results indicated that glycyrrhizic acid induces apoptosis through extrinsic/intrinsic apoptotic signaling pathways and diminishes EGFR/AKT/ERK-modulated metastatic potential in HCC in vitro and in vivo.

Molecular mechanisms of bufadienolides and their novel strategies for cancer treatment

Bufadienolides are cardioactive C24 steroids with an α-pyrone ring at position C17. In the last ten years, accumulating studies have revealed the anticancer activities of bufadienolides and their underlying mechanisms, such as induction of autophagy and apoptosis, cell cycle disruption, inhibition of angiogenesis, epithelial-mesenchymal transition (EMT) and stemness, and multidrug resistance reversal. As Na⁺/K⁺-ATPase inhibitors, bufadienolides have inevitable cardiotoxicity. Short half-lives, poor stability, low plasma concentration and oral bioavailability in vivo are obstacles for their applications as drugs. To improve the drug potency of bufadienolides and reduce their side effects, prodrug strategies and drug delivery systems such as liposomes and nanoparticles have been applied. Therefore, systematic and recapitulated information about the antitumor activity of bufadienolides, with special emphasis on the molecular or cellular mechanisms, prodrug strategies and drug delivery systems, is of high interest. Here, we systematically review the anticancer effects of bufadienolides and the molecular or cellular mechanisms of action. Research advancements regarding bufadienolide prodrugs and their tumor-targeting delivery strategies are critically summarized. This work highlights recent scientific advances regarding bufadienolides as effective anticancer agents from 2011 to 2019, which will help researchers to understand the molecular pathways involving bufadienolides, resulting in a selective and safe new lead compound or therapeutic strategy with improved therapeutic applications of bufadienolides for cancer therapy.

Hesperetin alleviates doxorubicin-induced migration in 4T1 breast cancer cells

Background

Hesperetin (Hst), a citrus flavanone, is widely distributed among citrus fruits, including lemons. Hst has been shown to possess bioactivity as an antioxidant, anti-inflammatory, anti-allergic, hypolipidemic, vasoprotector, and anticancer agent. This study aimed to identify potential combinations of Hst and the chemotherapeutic agent doxorubicin (Dox) as co-chemotherapy agents against 4T1 murine metastatic breast cancer cells.

Results

MTT assay results showed that Hst exhibited cytotoxic effect in 4T1 cells, and its combination with Dox showed a synergistic effect based on the CI value. The combination of Hst and Dox increased G2/M phase cell cycle arrest and apoptosis induction. The combination of Hst and Dox inhibited migration and decreased MMP-9 expression in 4T1 cells.

Conclusion

In conclusion, the results of this study show that Hst has potential as a Dox co-chemotherapy against 4T1 cells by inducing G2/M phase cell cycle arrest and apoptosis. More importantly, Hst reduces Dox-induced migration and decreases MMP-9 expression.

Plantamajoside inhibits the proliferation and epithelial-to-mesenchymal transition in hepatocellular carcinoma cells via modulating hypoxia-inducible factor-1α-dependent gene expression

As a potential antitumor herbal medicine, plantamajoside (PMS) benefits the treatment of many human malignances. However, the role of PMS in the progression of hepatocellular carcinoma (HCC) and the related molecular mechanisms is still unknown. Here, we proved that the cell viabilities of HepG2 cells were gradually decreased with the increasing concentrations of CoCl₂ and/or PMS via cell counting kit-8 assay. Meanwhile, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and western blot assays were used to further confirm that PMS inhibited the CoCl₂ -induced cell proliferation in HepG2 cells via suppressing the Ki67 and proliferating cell nuclear antigen expressions. We also performed wound-healing and transwell assays and demonstrated that PMS inhibited CoCl₂ -induced migration and invasion in HepG2 cells via suppressing the epithelial-mesenchymal transition (EMT) process. In addition, the use of 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole further proved that PMS inhibited the malignant biological behaviors of HepG2 cells under hypoxic condition by suppressing the hypoxia-inducible factor-1α (HIF-1α) expression. Besides, we further confirmed that PMS suppressed the growth and metastasis of implanted tumors in vivo. Given that PMS suppressed the proliferation and EMT induced by CoCl₂ in HCC cells via downregulating HIF-1α signaling pathway, we provided evidence that PMS might be a novel anti-cancer drug for HCC treatment.

Silencing of long noncoding RNA LEF1-AS1 prevents the progression of hepatocellular carcinoma via the crosstalk with microRNA-136-5p/WNK1

Long noncoding RNAs (lncRNAs) have been recognized as cancer-associated biological molecules, favoring hepatocellular carcinoma (HCC) progression. This study was conducted to elucidate the effects lncRNA lymphoid enhancer-binding Factor 1 antisense RNA (LEF1-AS1) on the pathological development of HCC, along with the crosstalk involving microRNA-136-5p (miR-136-5p) and with-no-K (lysine) kinase 1 (WNK1). The study recruited primary HCC tissues and their corresponding nonneoplastic liver tissues. The gain- and loss-of-function studies were performed in HCC cells HuH-7 and tumor xenografts in nude mice. The dual luciferase reporter gene assay system, RNA pull-down, and radioimmunoprecipitation assays were applied to detect their interactions among lncRNA LEF1-AS1, miR-136-5p, and WNK1. 5-Ethynyl-2'-deoxyuridine staining, scratch test, Transwell assays, and in vitro tube formation assays were conducted to examine HCC cell proliferation, migration, and invasion and HUVEC angiogenesis. HCC tissues and cells contained high lncRNA LEF1-AS1 expression. LncRNA LEF1-AS1 upregulation triggered markedly increased HCC cell proliferation, migration, and invasion and human umbilical vein endothelial cell angiogenesis. In vivo silencing lncRNA LEF1-AS1 resulted in reduced tumor cell vitality and matrix metalloproteinase-9 and the vascular endothelial growth factor expression. Additionally, the role of lncRNA LEF1-AS1 was found to be largely dependent on WNK1. Association of lncRNA LEF1-AS1 with WNK1 blocked the inhibitory effect of miR-136-5p on WNK1, which was confirmed by in vivo experiments. Altogether, our results revealed an important role of lncRNA LEF1-AS1 in regulating the HCC progression by regulating WNK1, providing a potential biomarker for the therapeutic modalities regarding HCC.

Polyphyllin II inhibits liver cancer cell proliferation, migration and invasion through downregulated cofilin activity and the AKT/NF-κB pathway

The morbidity and mortality of primary liver cancer is one of the highest amongst all cancers. Deficiency of effective treatment and characteristics of cancer metastasis are believed to be responsible for this situation, thus a great demand is required for new agent development. Polyphyllin II (PP2), an important steroidal saponin extracted from Rhizoma Paris, has emerged as a potential anti-cancer agent, but the effects of PP2 in liver cancers and its underlying mechanisms remain unexplored. In our study, we found that PP2 could remarkably suppress the proliferation of two liver cancer cell lines, HepG2 and BEL7402, resulting in significant cell death. Besides, low doses of PP2 have displayed properties that inhibit cellular motility and invasion of liver cancer cells. In addition, we have found that PP2-mediated cofilin activity suppression was implicated in the inhibition of liver cancer cell motility. Decreased expression of two major hydrolytic enzymes (MMP2/MMP9), through the AKT/NF-κB signaling pathway may also be also responsible for this process. Rescue experiments done with either non-phosphorylatable mutant cofilin-1 (S3A) transfection or an activator of the AKT pathway significantly reversed the inhibition effects of PP2 on liver cancer cells. Taken together, we report a potential agent for liver cancer treatment and reveal its underlying mechanisms.

Metabolites from Bufo gargarizans (Cantor, 1842): A review of traditional uses, pharmacological activity, toxicity and quality control

ETHNOPHARMACOLOGICAL RELEVANCE

Bufo gargarizans (Cantor, 1842) (BGC), a traditional medicinal animal distributed in many provinces of China, is well known for the pharmaceutical value of Chansu and Chanpi. As traditional Chinese medicines (TCMs), Chansu and Chanpi, with their broad-spectrum of therapeutic applications, have long been applied to detoxification, anti-inflammation, analgesia, etc. OVERARCHING OBJECTIVE: We critically analyzed the current evidence for the traditional uses, chemical profiles, pharmacological activity, toxicity and quality control of BGC (Bufonidae family) to provide a scientific basis for future in-depth studies and perspectives for the discovery of potential drug candidates.

METHODOLOGY

All of the available information on active constituents and TCMs derived from BGC was obtained using the keywords "Bufo gargarizans", "Chansu", "Chanpi", "Huachansu", or "Cinobufacini" through different electronic databases, including PubMed, Web of Science, Chinese National Knowledge Infrastructure (CNKI), the Wanfang Database, and Pharmacopoeia of China. In addition, Chinese medicine books from different times were used to elucidate the traditional uses of BGC. Electronic databases, including the "IUCN Red List of Threatened Species", "American Museum of Natural History" and "AmphibiaWeb Species Lists", were used to validate the scientific name of BGC.

RESULTS

To date, about 118 bufadienolide monomers and 11 indole alkaloids have been identified from BGC in total. The extracts and isolated compounds exhibit a wide range of in vitro and in vivo pharmacological effects. The literature search demonstrated that the ethnomedicinal uses of BGC, such as detoxification, anti-inflammation and the ability to reduce swelling and pain associated with infections, are correlated with its modern pharmacological activities, including antitumor, immunomodulation and attenuation of cancer-derived pain. Bufadienolides and indole alkaloids have been regarded as the main active substances in BGC, among which bufadienolides have significant antitumor activity. Furthermore, the cardiotoxicity of bufadienolides was discussed, and the main molecular mechanism involves in the inhibition of Na⁺/K⁺-ATPase. Besides, with the development of modern analytical techniques, the quality control methods of BGC-derived TCMs are being improved constantly.

CONCLUSIONS

An increasing number of reports suggest that BGC can be regarded as an excellent source for exploring the potential antitumor constituents. However, the future antitumor research of BGC needs to follow the standard pharmacology guidelines, so as to provide comprehensive pharmacological information and aid the reproducibility of the data. Besides, to ensure the efficacy and safety of BGC-derived TCMs, it is vital to construct a comprehensive quality evaluation model on the basis of clarifying pharmacodynamic-related and toxicity-related compositions.

Alisol A Suppresses Proliferation, Migration, and Invasion in Human Breast Cancer MDA-MB-231 Cells

Natural products are a precious source of promising leads for the development of novel cancer therapeutics. Recently, triterpenoids in Alismatis rhizoma has been widely demonstrated for their anti-cancer activities in cancer cells. In this study, we examined the inhibitory effects of alisol A in human breast cancer cells. We demonstrated that alisol A exhibited significant anti-proliferative effects in MDA-MB-231 cells and this response was related to autophagy induction. Alisol A-induced autophagy was supported by the triggered autophagosome formation and increased LC3-II levels. Interestingly, autophagy inhibitor 3-MA significantly reversed the cytotoxic effects induced by alisol A. Meanwhile, alisol A-induced autophagy was significantly inhibited by 3-MA in MDA-MB-231 cells. Cell cycle analysis revealed that alisol A arrested the cell cycle at G0/G1 phase. The expression level of cell cycle regulatory proteins cyclin D1 was significantly down regulated. In addition, the suppression of NF-κB and PI3K/Akt/mTOR pathways in MDA-MB-231 cells was observed. Furthermore, alisol A significantly suppressed the migration and invasion of MDA-MB-231 cells by inhibiting the expression levels of MMP-2 and MMP-9. Taken together, our results demonstrated that alisol A could inhibit the proliferation and metastasis of MDA-MB-231 cells. It could be a promising agent for breast cancer therapy.

Prevention of early liver metastasis after pancreatectomy by perioperative administration of a nuclear factor-κB inhibitor in mice

BACKGROUND

Liver metastasis is a common problem after pancreatectomy for pancreatic cancer. In pancreatic cancer cells, nuclear factor-κB is activated constitutively. Nuclear factor-κB activates matrix metalloproteinase-2/9, which plays an important role in cancer metastasis. Because the serine protease inhibitor FUT-175 suppresses nuclear factor-κB, we hypothesized that perioperative treatment with FUT-175 for pancreatic cancer may help to prevent liver metastasis.

METHODS

We compared in vitro cell viability, cell invasiveness, nuclear factor-κB signaling, and the expression levels of matrix metalloproteinase signals between the control group (C group) and the FUT-175 group (F group) using the murine pancreatic cancer cells PAN02. In addition, we evaluated the in vivo effect of pretreatment with FUT-175 using an established model of liver metastasis in mice. Metastatic liver lesions were assessed with magnetic resonance imaging. Liver recurrence and overall survival were evaluated. Also, the antimetastatic effect of systemic administration of FUT-175 was examined.

RESULTS

FUT-175 did not suppress the cell viability of PAN02 cells at or after 24 hours of treatment (P > .05); however, cell invasion was suppressed in the F group compared with the C group (P < .05). The levels of nuclear factor-κB activation, membrane type-1 (MT-1) matrix metalloproteinase (MMP)/matrix metalloproteinase-14 (MMP-14), and matrix metalloproteinase-2/9 (MMP-2/9) were lower in the F group compared with the C group. In vivo, both disease-free and overall survivals were prolonged in the F group compared with the C group. Systemic administration was also effective in suppressing the number of metastases.

CONCLUSION

Perioperative treatment with FUT-175 may help to prevent early liver metastasis after pancreatectomy for pancreatic cancer.

Identification of angiogenesis-inhibiting peptides from Chan Su

Chan Su is a traditional medicine prepared from toxic secretions from the auricular and skin glands of Chinese toads. Previous studies show that active components in Chan Su can inhibit the proliferation of tumor cells. To study the effect of Chan Su peptides on angiogenesis, fresh Chan Su was collected and its component peptides were isolated by an extraction and precipitation method. A high-performance liquid chromatography (HPLC) fingerprint of the Chan Su component peptides revealed that there were more than 18 peptide component peaks. We demonstrate that Chan Su peptides inhibit angiogenesis in vitro by inhibiting human umbilical vein endothelial cell (HUVEC) proliferation and tube formation in a dose-dependent manner. Western blots indicated that Chan Su peptides inhibited the protein expression of VEGF165 and Ras, leading us to conclude that Chan Su peptide components exert anti-angiogenic effects by suppressing the VEGF165-VEGFR2-Ras signalling pathway. Finally, we identified the partial amino acid sequences of seven Chan Su peptides using the shotgun proteomics method.

Overexpression of MAP3K3 promotes tumour growth through activation of the NF-κB signalling pathway in ovarian carcinoma

Mitogen-activated protein kinase kinase kinase 3 (MAP3K3), a member of the serine/threonine protein kinase family, is ubiquitously expressed and acts as an oncogene. However, the expression and exact molecular mechanism of MAP3K3 in ovarian carcinoma (OC) remain unclear. Here, we found that MAP3K3 protein was highly expressed in 70.5% of high-grade serous ovarian carcinoma (HGSOC) samples. MAP3K3 overexpression was significantly associated with the FIGO stage and chemotherapy response. Additionally, MAP3K3 overexpression was associated with reduced disease-free survival and overall survival. In vitro experiments showed that MAP3K3 overexpression promoted cell proliferation, inhibited apoptosis, and enhanced the migration and invasion of OC cells. Moreover, in vivo tumourigenesis experiments confirmed that silencing MAP3K3 significantly reduced the growth rate and volume of transplanted tumours in nude mice. Drug sensitivity experiments demonstrated that differential expression of MAP3K3 in OC cell lines correlates with chemotherapy resistance. Functionally, the MAP3K3 gene regulated the malignant biological behaviour of OC cells by mediating NF-κB signalling pathways, affecting the downstream epithelial-mesenchymal transition and cytoskeletal protein expression. Our results unveiled the role of MAP3K3 in mediating NF-κB signalling to promote the proliferation, invasion, migration, and chemotherapeutic resistance of OC cells, highlighting a potential new therapeutic and prognostic target.

Casticin inhibits human prostate cancer DU 145 cell migration and invasion via Ras/Akt/NF-κB signaling pathways

Casticin, a polymethoxyflavone derived from natural plants, has biological activities including induction of cell apoptosis. In this study, we showed the beneficial effects of casticin on the inhibition of prostate cancer cell metastasis. Casticin reduced total viable cell number, thus, we selected low doses of casticin for following experiments. Casticin decreased cell mobility, suppressed cell migration and invasion, and reduced cell gelatinolytic activities of MMP-2/-9. Furthermore, casticin inhibited the protein levels of AKT, GSK3 αβ, Snail, and MMPs (MMP-2, -9, -13, and -7) at 24 and 48 hr treatment. Casticin diminished the expressions of NF-κB p65, GRB2, SOS-1, MEK, p-ERK1/2, and p-JNK1/2 at 48 hr treatment only. However, casticin reduced the level of E-cadherin at 24 hr treatment but elevated at 48 hr. The novel findings suggest that casticin may represent a new and promising therapeutic agent for the metastatic prostate cancer. PRACTICAL APPLICATIONS: Casticin derived from natural plants had been used for Chinese medicine in Chinese population for thousands of years. In the present study, casticin attenuated metastatic effects, including decreasing viable cell number, inhibiting the migration, invasion, and adhesion, and reducing matrix metalloproteinases activity on human prostate DU 145 cancer cells. In addition, the results also provided possible pathways involved in casticin anti-metastasis mechanism. We conclude that casticin may be an aptitude anticancer agent or adjuvant for the metastatic prostate cancer in the future.

New therapeutic aspects of steroidal cardiac glycosides: the anticancer properties of Huachansu and its main active constituent Bufalin

Aim of the review

In the past decade, increasing research attention investigated the novel therapeutic potential of steroidal cardiac glycosides in cancer treatment. Huachansu and its main active constituent Bufalin have been studied in vitro, in vivo and clinical studies. This review aims to summarize the multi-target and multi-pathway pharmacological effects of Bufalin and Huachansu in the last decade, with the aim of providing a more comprehensive view and highlighting the recently discovered molecular mechanisms.

Results

Huachansu and its major derivative, Bufalin, had been found to possess anti-cancer effects in a variety of cancer cell lines both in vitro and in vivo. The underlying anti-cancer molecular mechanisms mainly involved anti-proliferation, apoptosis induction, anti-metastasis, anti-angiogenesis, epithelial-mesenchymal transition inhibition, anti-inflammation, Na⁺/K⁺-ATPase activity targeting, the steroid receptor coactivator family inhibitions, etc. Moreover, the potential side-effects and toxicities of the toad extract, Huachansu, and Bufalin, including hematological, gastrointestinal, mucocutaneous and cardiovascular adverse reactions, were reported in animal studies and clinic trails.

Conclusions

Further research is needed to elucidate the potential drug-drug interactions and multi-target interaction of Bufalin and Huachansu. Large-scale clinical trials are warranted to translate the knowledge of the anticancer actions of Bufalin and Huachansu into clinical applications as effective and safe treatment options for cancer patients in the future.

Fluoxetine Induces Apoptosis through Extrinsic/Intrinsic Pathways and Inhibits ERK/NF-κB-Modulated Anti-Apoptotic and Invasive Potential in Hepatocellular Carcinoma Cells In Vitro

The aim of the present study was to verify the effects of fluoxetine on dysregulation of apoptosis and invasive potential in human hepatocellular carcinoma (HCC) SK-Hep1 and Hep3B cells. Cells were treated with different concentrations of fluoxetine for different times. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assays were used for testing the effects of fluoxetine on cell viability. The regulation of apoptosis signaling, and anti-apoptotic, proliferation, and metastasis-associated proteins after fluoxetine treatment were assayed by flow cytometry and Western blotting assay. The detection of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation after fluoxetine treatment was performed by NF-κB reporter gene assay. The results demonstrated that fluoxetine significantly reduced cell viability, cell migration/invasion, NF-κB, extracellular signal-regulated kinases (ERK) activation, and expression of anti-apoptotic (Cellular FLICE (FADD-like IL-1β-converting enzyme)-inhibitory protein (C-FLIP), Myeloid cell leukemia-1 (MCL-1), X-Linked inhibitor of apoptosis protein (XAIP), and Survivin), proliferation (Cyclin-D1), angiogenesis (vascular endothelial growth factor (VEGF)), and metastasis-associated proteins (matrix metalloproteinase-9 (MMP-9)). Fluoxetine also significantly induced apoptosis, unregulated extrinsic (activation of first apoptosis signal protein and ligand (Fas/FasL), and caspase-8) and intrinsic (loss of mitochondrial membrane potential (ΔΨm) pathways and increased Bcl-2 homologous antagonist killer (BAK) apoptosis signaling. Taken together, these results demonstrated that fluoxetine induced apoptosis through extrinsic/intrinsic pathways and diminished ERK/NF-κB-modulated anti-apoptotic and invasive potential in HCC cells in vitro.

Transferrin and folic acid co-modified bufalin-loaded nanoliposomes: preparation, characterization, and application in anticancer activity

Aim

The aim of this study was to prepare transferrin (Tf) and folic acid (FA) co-modified bufalin (BF) liposomes for lung cancer treatment.

Method

In this study, (FA+Tf) BF-LPs were prepared using the high-pressure homogenization method.

Results

The EE% and DL% of prepared LPs were 82.3% and 10.7%, respectively, and the mean diameter was 120.4 nm from three batches. In vitro release showed that the release of BF from (FA+Tf) BF-LPs was slow with burst effects at an early stage. In vitro cytotoxicity assay showed that (FA+Tf) BF-LPs had a superior antiproliferative effect on A549 cells. An in vivo imaging study indicated that (FA+Tf) BF-LPs had obvious targeting characteristics on subcutaneous tumor, with the potential to actively deliver drugs to tumor tissues. In terms of the in vivo antitumor activity, (FA+Tf) BF-LPs treated mice showed a significantly suppressed tumor growth and no systemic toxicity in the body.

Conclusion

Through this study, it was found that the Tf and FA co-modified BF could be a very promising lung target preparation.

The Development of Toad Toxins as Potential Therapeutic Agents

Toxins from toads have long been known to contain rich chemicals with great pharmaceutical potential. Recent studies have shown more than 100 such chemical components, including peptides, steroids, indole alkaloids, bufogargarizanines, organic acids, and others, in the parotoid and skins gland secretions from different species of toads. In traditional Chinese medicine (TCM), processed toad toxins have been used for treating various diseases for hundreds of years. Modern studies, including both experimental and clinical trials, have also revealed the molecular mechanisms that support the development of these components into medicines for the treatment of inflammatory diseases and cancers. More recently, there have been studies that demonstrated the therapeutic potential of toxins from other species of toads, such as Australian cane toads. Previous reviews mostly focused on the pharmaceutical effects of the whole extracts from parotoid glands or skins of toads. However, to fully understand the molecular basis of toad toxins in their use for therapy, a comprehensive understanding of the individual compound contained in toad toxins is necessary; thus, this paper seeks to review the recent studies of some typical compounds frequently identified in toad secretions.

Serum MMP-2 as a potential predictive marker for papillary thyroid carcinoma

OBJECTIVE

The prevalence of papillary thyroid carcinoma (PTC) is rising rapidly. However, there are no reliable serum biomarkers for PTC. This study aimed to investigate the validity of preoperative serum matrix metalloproteinase-2 (MMP-2) as a biomarker for predicting prognosis of PTC after total or partial thyroidectomy.

METHODS

Male patients with PTC or a benign thyroid nodule (BTN) and healthy controls (HCs) were retrospectively included. Receiver operating characteristic (ROC) curves were constructed to evaluate the performance of preoperative serum MMP-2 in diagnosing PTC, predicting lymph node metastasis (LNM), and predicting structurally persistent/recurrent disease (SPRD). Multivariate logistic regression and Cox regression were applied to identify independent risk factors for SPRD.

RESULTS

The preoperative serum MMP-2 concentration in the PTC group was higher than those in BTN and HC groups. The concentration of postoperative serum MMP-2 decreased in comparison with pre-operation. ROC curves showed that serum MMP-2 could differentially diagnose PTC from BTN at the cutoff value of 86.30 ng/ml with an area under the curve (AUC) of 0.905 and could predict central LNM (CLNM) at the cutoff value of 101.55 ng/ml with an AUC of 0.711. Serum MMP-2 ≥101.55 ng/ml, age ≥45 years, and advanced TNM stage were independent risk factors for CLNM. Patients with SPRD had a higher median MMP-2 level (149.22 ng/ml) than patients without SPRD (104.55 ng/ml). Serum MMP-2 at the cutoff value of 144.04 ng/ml could predict SPRD in PTC patients with an AUC of 0.803. Advanced TNM stage and serum MMP-2 ≥144.04 ng/ml were independent risk factors for SPRD. Patients with serum MMP-2 ≥144.04 ng/ml had a worse clinical outcome than those with MMP-2 <144.04 ng/ml.

CONCLUSION

Preoperative serum MMP-2 may serve as a biomarker for diagnosing PTC and a predictive indicator for LNM and SPRD in male patients with PTC.

Molecular mechanisms underlying the antimetastatic activity of bufalin

Bufalin is a monomer compound extract from Chansu, which is a traditional Chinese medicine obtained from the skin and parotid venom glands of toads, such as Bufo bufo gargarizans Cantor and Bufo melanostictus Schneider. Chansu had been used in traditional Chinese medicine for >1,000 years due to its cardiac, anti-inflammatory and anticancer properties. Previous studies identified bufalin as the main anticancer compound of Chansu, and recent evidence has corroborated its anticancer properties. Bufalin inhibits cancer cell proliferation, induces cell cycle arrest, induces cancer cell apoptosis, inhibits neovascularization, induces cell differentiation, inhibits cancer metastasis and invasion, and enhances chemotherapeutic drug sensitivity. However, the function and mechanism of bufalin in metastatic cancer cells have not yet been expounded. The aim of the present review was to discuss the recent progress and prospects of bufalin in the prevention of cancer metastasis, particularly in inhibiting epithelial-to-mesenchymal transition.

Bufalin suppresses hepatocarcinogenesis by targeting β-catenin/TCF signaling via cell cycle-related kinase

Hepatocellular carcinoma (HCC) is one of the most aggressive malignant tumors, of which treatment options are limited especially in advanced stage. Bufalin, the major digoxin-like component of the traditional Chinese medicine Chansu, exhibits significant antitumor activities in hepatoma cells, but the potential mechanism is obscure. Cell cycle-related kinase (CCRK) is recently identified to be a crucial oncogenic master regulator to drive hepatocarcinogenesis. Here we investigated the molecular function of bufalin on CCRK-regulated signaling pathway, and expounded the underlying mechanism in HCC suppression. In vitro with PLC5 HCC cells and human immortal LO2 cells, proliferation, malignant transformation and cell cycle progression assays were performed to evaluate the antitumor effect of bufalin. In vivo with xenograft and orthotopic mice models, tumor growths with weight and volume change were assessed with or without bufalin treatment. Western blot, RT-qPCR, immunofluorescence and immunohistochemistry were conducted to examine the expression level of CCRK and β-catenin/TCF signaling cascade. We revealed that bufalin suppresses PLC5 HCC cell proliferation, transformation and cell cycle progression rather than LO2 cells, which is correlated with CCRK-mediated β-catenin/TCF signaling. It was also confirmed in mice model. Thus, bufalin is a potential anti-HCC therapeutic candidate through the inhibition of CCRK-driven β-catenin/TCF oncogenic signaling pathway.

Bufadienolides induce p53-mediated apoptosis in esophageal squamous cell carcinoma cells in vitro and in vivo

Bufadienolides are a type of cardiotonic steroids isolated from the skin and parotid venom glands of the toad Bufo bufo gargarizans Cantor, and exhibit wide-spectrum anticancer activities. However, the effects and mechanisms of bufadienolides on esophageal squamous cell carcinoma (ESCC) cells remain unknown. In the present study, the anticancer activities of two bufadienolides, bufotalin and bufalin, were examined in vitro and in vivo. The results demonstrated that bufotalin and bufalin effectively inhibited the viability of ESCC cells, with half-maximal inhibitory concentration (IC₅₀) values of 0.8–3.6 µM. However, bufotalin and bufalin exhibited lower toxicity towards Het-1A human esophageal squamous cells, indicating their high selectivity towards cancer cells. Mechanistic studies revealed that bufotalin effectively induced ESCC cell apoptosis, as characterized by DNA fragmentation and nuclear condensation, which was primarily mediated through activation of caspase family members. In addition, treatment of ESCC cells with bufotalin markedly activated tumor protein p53 (p53) phosphorylation. Transfection of cells with p53 small interfering RNA markedly inhibited bufotalin-induced p53 phosphorylation and significantly inhibited bufotalin-induced cell apoptosis. Furthermore, bufotalin demonstrated in vivo anticancer efficacy in a tumor-bearing nude mice model, where bufotalin effectively inhibited Eca-109 xenograft tumor growth in a time- and dose-dependent manner, through activation of the p53 signaling pathway. Collectively, the results from the present study suggested that bufadienolides exert anticancer effects against ESCC by regulating the p53 signaling pathway.

Actinidia callosa var. callosa suppresses metastatic potential of human hepatoma cell SK-Hep1 by inhibiting matrix metalloproteinase-2 through PI3K/Akt and MAPK signaling pathways

BACKGROUND

Cancer cell metastasis involving multi-step procedures and cytophysiological property changes may make difficult in the clinical management and death rate increasing.

RESULTS

In this study, we first observed that ethyl acetate fraction of Actinidia callosa var. callosa (EAAC) carry out a dose-dependent inhibitory effect without cytotoxicity on the mobility and invasion of highly metastatic SK-Hep1 cells. To investigate the EAAC in cancer metastasis, SK-Hep1 cells were treated with EAAC at various concentrations and then subjected to gelatin zymography, casein zymography and western blot to study the impacts of EAAC on metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-1/2 (TIMP-1/2), respectively. Our results showed that EAAC treatment may decrease the expressions of MMP-2 and enhance the expression of TIMP-1/2 in a concentration-dependent manner. EAAC also inhibited effect on the phosphorylation of mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3-kinase/serine/threonine protein kinase [or protein kinase B (PI3K/Akt)] and focal adhesion kinase (FAK).

CONCLUSIONS

These results indicate that EAAC inhibited SK-Hep1 cell of metastasis by reduced protein level of MMP-2 through the suppression of MAPK and FAK signaling pathway and of the activity of PI3K/Akt. These findings suggest that EAAC may be used as an antimetastatic agent.

Methylation-mediated repression of microRNA-129-2 suppresses cell aggressiveness by inhibiting high mobility group box 1 in human hepatocellular carcinoma

Aberrant expression of microRNAs (miRNAs) and its dysfunction have been revealed as crucial modulators of cancer initiation and progression. MiR-129-2 has been reported to play a tumor suppressive role in different human malignancies. Here, we demonstrated that miR-129-2 was significantly decreased in hepatocellular carcinoma (HCC) tissues and cell lines. Furthermore, miR-129-2 was expressed at significant lower levels in aggressive and recurrent tumor tissues. Clinical analysis indicated that miR-129-2 expression was inversely correlated with venous infiltration, high Edmondson-Steiner grading and advanced tumor-node-metastasis (TNM) stage in HCC. Notably, miR-129-2 was an independent prognostic factor for indicating overall survival (OS) and disease-free survival (DFS) of HCC patients. Ectopic expression of miR-129-2 inhibited cell migration and invasion in vitro and in vivo. Furthermore, we confirmed that high mobility group box 1 (HMGB1) was a direct target of miR-129-2, and it abrogated the function of miR-129-2 in HCC. Mechanistic investigations showed that miR-129-2 overexpression inhibited AKT phosphorylation at Ser473 and decreased the expression of matrix metalloproteinase2/9 (MMP2/9). Upregulation of p-AKT abolished the decreased cell migration and invasion induced by miR-129-2 in HCC. Whereas inhibition of Akt phosphorylation significantly decreased HMGB1-enhanced HCC cell migration and invasion. Moreover, we found that miR-129-2 was downregulated by DNA methylation, and demethylation of miR-129-2 increased miR-129-2 expression in HCC cells and resulted in significant inhibitory effects on cell migration and invasion. In conclusion, miR-129-2 may serve as a prognostic indicator for HCC patients and exerts tumor suppressive role, at least in part, by inhibiting HMGB1.

β-mangostin suppresses human hepatocellular carcinoma cell invasion through inhibition of MMP-2 and MMP-9 expression and activating the ERK and JNK pathways

β-mangostin is a dietary xanthone that has been reported to have the anticancer properties in some human cancer cell types. However, the antimetastatic effect and molecular mechanism of β-mangostin action in human hepatocellular carcinoma (HCC) cells remain unknown. In this study, we found that β-mangostin did not induce cytotoxicity in human HCC cells (SK-Hep-1, Huh-7 and HA22T/VGH cells). β-mangostin could inhibit migration and invasion of human HCC cells. Meanwhile, β-mangostin significantly decreased the protein activities and expression of matrix metalloproteinase (MMP)-2 and MMP-9 via increasing the activation of MEK1/2, ERK1/2, MEK4 and JNK1/2 signaling pathways. Furthermore, using specific inhibitor for ERK1/2 (PD98059) and JNK1/2 (JNKII) significantly restored the expression of MMP-2/-9 and invasion by β-mangostin treatment in Huh-7 cells. In addition, β-mangostin effectively restored the protein levels and transcription activity of MMP-2 and MMP-9 in siERK or siJNK-transfected Huh-7 cells, concomitantly with promotion on cell migration and invasion. Taken together, these findings are the first to demonstrate the antimetastatic activity of β-mangostin against human HCC cells, which may act as a promising therapeutic agent for the treatment of HCC.

Benzyl isothiocyanate and phenethyl isothiocyanate inhibit murine melanoma B16F10 cell migration and invasion in vitro

Benzyl isothiocyanate (BITC), and phenethyl isothiocyanate (PEITC) have been demonstrated to induce anticancer function in many human cancer cells and also inhibit cancer cell migration and invasion. However, there are no studies that show BITC and PEITC to inhibit cell migration and invasion in mouse melanoma B16F10 cells. In this study, we investigated anti-metastasis effects of BITC and PEITC in melanoma cancer cells in vitro. Under sub-lethal concentrations (from 1, 2.5 up to 5 µM), BITC and PEITC significantly inhibited cell mobility, migration and invasion nature of B16F10 cells. Gelatin zymography assay also showed that BITC and PEITC inhibited matrix metalloproteinase-2 (MMP-2) activity in B16F10 cells. PEITC reduced MAPK signaling associated proteins such as p-ERK1/2, p-p38 and p-JNK1/2 but BITC increased those MAPK signaling associated proteins. BITC and PEITC both suppressed the expression of RhoA, Ras, and SOS-1, however, PEITC increased FAK and GRB2 but BITC increased FAK at 48 h. Furthermore, PEITC decreased the expression of MMP-2 and tissue inhibitors of matrix metalloproteinases (TIMP) but BITC increased them. PEITC inhibited NF-κB protein levels and DNA binding which was confirmed by electrophoretic mobility shift (EMSA) assay. Based on these observations, we suggest that BITC and PEITC can be used in anti-metastasis of melanoma cells in the future.

Identification of anti-tumor components from toad venom

Secretion of granular glands from the skin of amphibians is a fascinating resource of active substances, particularly for cancer therapy in clinical practice of Traditional Chinese Medicine. A variety of anti-tumor peptides have been isolated from different toads and frogs; however, no anti-tumor peptides are reported in toad venom of Bufo gargarizans. Firstly, soluble fraction from fresh toad venom (FTV) was compared with that from dried toad venom (DTV), using HPLC analysis. It was revealed that FTV has a different HPLC chromatography compared with DTV. Soluble fraction of FTV is more toxic to SH-SY5Y cells than that of DTV, as evaluated by MTT assay. Secondly, it was identified that protein components from soluble fractions of FTV and DTV possess different patterns by SDS-PAGE analysis, and proteins from FTV are also more toxic than that from DTV. Thirdly, an immobilized basic fibroblast growth factor (bFGF) affinity column was used to isolate bFGF-binding components from soluble fraction of FTV, and it was identified that bFGF-binding components prohibited bFGF-dependent neurite growth of SH-SY5Y cells. Finally, it was identified that bFGF-binding components activated apoptosis via upregulation of caspase-3 and caspase-8 expression in SH-SY5Y cells. These data suggest that FTV contains active components that interact with bFGF and activate apoptosis in SH-SY5Y cells.

Arenobufagin activates p53 to trigger esophageal squamous cell carcinoma cell apoptosis in vitro and in vivo

Esophageal squamous cell carcinoma (ESCC) is often diagnosed at late incurable stage and lacks effective treatment strategy. Bufadienolides are cardiotonic steroids isolated from the skin and parotid venom glands of the toad Bufo bufo gargarizans Cantor with novel anticancer activity. However, there is little information about the effects and action mechanisms of bufadienolides on ESCC cells. In this study, the in vitro and in vivo anti-ESCC activities of bufadienolides, including bufalin (Bu) and arenobufagin (ArBu), were examined and the underlying molecular mechanisms were elucidated. The results showed that ArBu exhibited higher anticancer efficacy than Bu against a panel of five ESCC cells, with IC₅₀ values ranging from 0.8 μM to 3.6 μM. However, ArBu showed lower toxicity toward Het-1A human normal esophageal squamous cells, indicating its great selectivity between cancer and normal cells. Moreover, ArBu effectively induced ESCC cell apoptosis mainly by triggering caspase activation through intrinsic and extrinsic pathways. Treatment of ESCC cells also significantly activated p53 signaling by enhancing its phosphorylation. Interestingly, transfection of cells with p53 small interfering RNA significantly inhibited the ArBu-induced p53 phosphorylation and the overall apoptotic cell death. Furthermore, ArBu also demonstrated novel in vivo anticancer efficacy by inhibiting the tumor growth through activation of p53 pathway. Taken together, these results demonstrate the p53-targeting therapeutic potential of bufadienolides against ESCC.

Radiosynthesis and pharmacokinetics of [18F]fluoroethyl bufalin in hepatocellular carcinoma-bearing mice

Purpose

Bufalin, the main component of a Chinese traditional medicine chansu, shows convincing anticancer effects in a lot of tumor cell lines. However, its in vivo behavior is still unclear. This research aimed to evaluate how bufalin was dynamically absorbed after intravenous injection in animal models. We developed a radiosynthesis method of [¹⁸F]fluoroethyl bufalin to noninvasively evaluate the tissue biodistribution and pharmacokinetics in hepatocellular carcinoma-bearing mice.

Methods

[¹⁸F]fluoroethyl bufalin was synthesized with conjugation of 18F-CH₂CH₂OTs and bufalin. The radiochemical purity was proved by the radio-high-performance liquid chromatography (HPLC). The pharmacokinetic studies of [¹⁸F]fluoroethyl bufalin were then performed in Institute of Cancer Research (ICR) mice. Furthermore, the biodistribution and metabolism of [¹⁸F]fluoroethyl bufalin in HepG2 and SMMC-7721 tumor-bearing nude mice were studied in vivo by micro-positron emission tomography (micro-PET).

Results

The radiochemical purity (RCP) of [¹⁸F]fluoroethyl bufalin confirmed by radio-HPLC was 99%±0.18%, and [¹⁸F]fluoroethyl bufalin showed good in vitro and in vivo stabilities. Blood dynamics of [¹⁸F]fluoroethyl bufalin conformed to the two compartments in the ICR mice model. The pharmacokinetic parameters of [¹⁸F]fluoroethyl bufalin were calculated by DAS 2.0 software. The area under concentration–time curve (AUC_0–t) and the values of clearance (CL) were 540.137 μg/L·min and 0.001 L/min/kg, respectively. The half-life of distribution (t_1/2α) and half-life of elimination (t_1/2β) were 0.693 and 510.223 min, respectively. Micro-PET imaging showed that [¹⁸F]fluoroethyl bufalin was quickly distributed via the blood circulation; the major tissue biodistribution of [¹⁸F]fluoroethyl bufalin in HepG2 and SMMC-7721 tumor-bearing mice was liver and bladder.

Conclusion

[¹⁸F]fluoroethyl bufalin was accumulated rapidly in the liver at an early time point (5 min) post injection (pi) and then declined slowly, mainly through both the hepatic pathway and the renal pathway. Our study showed the biodistribution of [¹⁸F]fluoroethyl bufalin in micro-PET images and provided visible information for demonstrating the bioactivities of bufalin.

Bufalin inhibits gefitinib resistant NCI-H460 human lung cancer cell migration and invasion in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Bufalin, a component of Chan Su (frog), has been shown to have biological activities including anti-tumor effects. Gefitinib has been used as an anti-cancer drug in lung cancer patients; however, some patients eventually become gefitinib resistant.

AIM OF THE STUDY

In this study, we investigated anti-metastasis effects of bufalin in gefitinib resistant NCI-H460 lung cancer cells.

MATERIALS AND METHODS

The effects of the bufalin in gefitinib resistant NCI-H460 lung cancer cells were investigated on cell viability using flow cytometry. The adhesion capacity, wound healing assay, invasion and migration assay, and Western blot analysis were used to understand the molecular mechanisms in this study RESULTS: Under sub-lethal concentrations (from 2.5 up to 10nM), bufalin significantly inhibits cell adhension, migration and invasion nature of gefitinib resistant H460 cells. Western blotting assay revealed that bufalin depressed some of the key metastasis-related proteins, such as SOS-1, MMP-2 and Rho A underwent significant reduction. Phosphorylated Focal adhesion kinase (p-FAK), phosphorylated extracellular signal-regulated kinase (p-ERK1/2), Ras and E-cadherin were significantly reduced at 48h treatment. However, phosphorylated p38 (p-p38), phosphorylated c-Jun NH2-terminal kinase (p-JNK1/2) and NF-κBp65 were increased.

CONCLUSIONS

Based on these observations, we suggest that bufalin can be used in anti-metastasis of gefitinib resistant NCI-H460 lung cancer cells in the future.

Bufalin inhibits pancreatic cancer by inducing cell cycle arrest via the c-Myc/NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Bufalin, a cardiotonic steroid isolated from toad venom (bufo gargarizans Cantor or B. melanotictus Schneider), has widely demonstrated antitumor effects and exhibits potential antitumor activity in various human cancer cells lines.

AIMS OF THE STUDY

The main characteristic of cancers including pancreatic cancer is the ability of uncontrolled proliferation. The aim of this study is to clarify the underlying mechanism by which bufalin inhibits pancreatic cancer cell proliferation.

MATERIALS AND METHODS

The effect of bufalin on the suppression of tumor growth in vivo was studied in a bioluminescent mouse model generated using the pancreatic cancer cell line BxPC3-luc2 and the cytotoxicity was evaluated in BcPc3 and Sw1990 cells with MTT. Flow cytometry and western blotting analyses were utilized to detect the effect of bufalin on the cell cycle and to detect the cell cycle-related proteins, respectively. Then, a luciferase reporter assay was applied to screen the activity of potent transcription factors following bufalin exposure and their expression was detected by western blotting.

RESULTS

Bufalin suppressed tumor growth in a bioluminescence mouse model generated using BxPC3-luc2 cells and inhibited cell proliferation in vitro through inducing cell cycle arrest at S phase. Bufalin treatment inhibited cyclin D1 and cyclin E1 expression and therefore increased expression of p27, a regulatory molecular that controls cell cycle transition from S to G2 phase. Furthermore, luciferase reporter screening studies revealed that bufalin inhibited the expression and activity of the transcription factors c-Myc and NF-κB, which might cause cell cycle arrest at S phase and the inhibition of cell proliferation.

CONCLUSIONS

Taken together, our results indicate that bufalin can inhibit pancreatic cancer by targeting c-Myc, thus suggesting that the mechanism of c-Myc regulation by bufalin might be worthy of further study regarding its potential as a therapeutic target for pancreatic cancer treatment.

3'3-Diindolylmethane inhibits migration, invasion and metastasis of hepatocellular carcinoma by suppressing FAK signaling

Late stage hepatocellular carcinoma (HCC) usually has a low survival rate because it has high potential of metastases and there is no effective cure. 3'3-Diindolylmethane (DIM) is the major product of the acid-catalyzed oligomerization of indole-3-carbinol present in cruciferous vegetables. DIM has been proved to exhibit anticancer properties. In this study, we explored the effects and molecular mechanisms of anti-metastasis of DIM on HCC cells both in vitro and in vivo. We chose two HCC cell lines SMMC-7721 and MHCC-97H that have high potential of invasion. The results showed that DIM inhibited the proliferation, migration and invasion of these two cell lines in vitro. In addition, in vivo study demonstrated that DIM significantly decreased the volumes of SMMC-7721 orthotopic liver tumor and suppressed lung metastasis in nude mice. Focal Adhesion Kinase (FAK) is found over activated in HCC cells. We found that DIM decreased the level of phospho-FAK (Tyr397) both in vitro and in vivo. DIM inhibition of phospho-FAK (Tyr397) led to down-regulation of MMP2/9 and decreased potential of metastasis. DIM also repressed the migration and invasion induced by vitronectin through inactivation of FAK pathway and down-regulation of MMP2/9 in vitro. We also found that pTEN plays a role in down-regulation of FAK by DIM. These results demonstrated that DIM blocks HCC cell metastasis by suppressing tumor cell migration and invasion. The anti-metastasis effect of DIM could be explained to be its down-regulated expression and activation of MMP2/9 partly induced by up-regulation of pTEN and inhibition of phospho-FAK (Tyr397).

Bufalin Inhibits NCI-H460 Human Lung Cancer Cell Metastasis In Vitro by Inhibiting MAPKs, MMPs, and NF-κB Pathways

Bufalin, a component of Chan Su (a traditional Chinese medicine), has been known to have antitumor effects for thousands of years. In this study, we investigated its anti-metastasis effects on NCI-H460 lung cancer cells. Under sub-lethal concentrations (from 25 up to 100 nM), bufalin significantly inhibits the invasion and migration nature of NCI-H460 cells that were measured by Matrigel Cell Migration Assay and Invasion System. Bufalin also suppressed the enzymatic activity of matrix metalloproteinase (MMP)-9, which was examined by gelatin zymography methods. Western blotting revealed that bufalin depressed several key metastasis-related proteins, such as NF-κB, MMP-2, MMP-9, protein kinase C (PKC), phosphatidylinositol 3-kinase (PI3-K), phosphorylated Akt, growth factor receptor-bound protein 2 (GRB2), phosphorylated extracellular signal-regulated kinase (ERK), phosphorylated p38, and phosphorylated c-Jun NH2-terminal kinase (JNK). As evidenced by immunostaining and the electrophoretic mobility shift assay (EMSA), bufalin induced not only a decreased cytoplasmic NF-κB production, but also decreased its nuclear translocation. Several metastasis-related genes, including Rho-associated (Rho A), coiled-coil-containing protein kinase 1 (ROCK1), and focal adhesion kinase (FAK), were down-regulated after bufalin treatment. In conclusion, bufalin is effective in inhibiting the metastatic nature of NCI-H460 cells in low, sub-lethal concentrations. Such an effect involves many mechanisms including MMPs, mitogen-activated protein kinases (MAPKs) and NF-κB systems. Bufalin has a potential to evolve into an anti-metastasis drug for human lung cancer in the future.

Biological activities of skin and parotoid gland secretions of bufonid toads (Bufo bufo, Bufo verrucosissimus and Bufotes variabilis) from Turkey

Toad glandular secretions and skin extractions contain numerous natural agents which may provide unique resources for novel drug development. Especially the skin-parotoid gland secretions of toads from genus Bufo contain as many as 86 different types of active compounds, each with the potential of becoming a potent drug. In the present study, crude skin-parotoid gland secretions from Bufo bufo, Bufo verrucosissimus and Bufotes variabilis from Turkey were screened against various cancer cells together with normal cells using MTT assay. Furthermore, the antimicrobial properties of skin secretions were tested on selected bacterial and fungal species for assessing the possible medical applications. Antimicrobial activity of skin secretions was studied by determining minimal inhibitory concentration (MIC) in broth dilution method. Hemolytic activity of each skin-secretion was also estimated for evaluating pharmaceutical potential. Both skin-parotoid gland secretions showed high cytotoxic effect on all cancerous and non-cancerous cell lines with IC50 values varying between <0.1μg/ml and 6.02μg/ml. MIC results of antimicrobial activity tests were found to be between 3.9μg/ml and 250μg/ml. No hemolytic activities on rabbit red blood cells at concentrations between 0.5μg/ml and 50μg/ml were observed. In conclusion, skin-parotoid secretions of bufonid toads might be remarkable candidates for anti-cancer and antimicrobial agents without hemolytic activities.