Cantharidin suppressed breast cancer MDA-MB-231 cell growth and migration by inhibiting MAPK signaling pathway

Integrative approach using network pharmacology, bioinformatics, and experimental methods to explore the mechanism of cantharidin in treating colorectal cancer

Cantharidin, a terpenoid produced by blister beetles, has been used in traditional Chinese medicine to treat various ailments and cancers. However, its biological activity, impact, and anticancer mechanisms remain unclear. The Cantharidin chemical gene connections were identified using various databases. The GSE21815 dataset was used to collect the gene expression information. Differential gene analysis and gene ontology analyses were performed. Gene set enrichment analysis was used to assess the activation of disease pathways. Weighted gene co-expression network analysis and differential analysis were used to identify illness-associated genes, examine differential genes, and discover therapeutic targets via protein-protein interactions. MCODE analysis of major subgroup networks was used to identify critical genes influenced by Cantharidin, examine variations in the expression of key clustered genes in colorectal cancer vs. control samples, and describe the subject operators. Single-cell GSE188711 dataset was preprocessed to investigate Cantharidin's therapeutic targets and signaling pathways in colorectal cancer. Single-cell RNA sequencing was utilized to identify 22 cell clusters and marker genes for two different cell types in each cluster. The effects of different Cantharidin concentrations on colorectal cancer cells were studied in vitro. One hundred and ninety-seven Cantharidin-associated target genes and 480 critical genes implicated in the development of the illness were identified. Cantharidin significantly inhibited the proliferation and migration of HCT116 cells and promoted apoptosis at certain concentrations. Patients on current therapy develop inherent and acquired resistance. Our study suggests that Cantharidin may play an anti-CRC role by modulating immune function.

Cantharidin overcomes IL-2Rα signaling-mediated vorinostat resistance in cutaneous T-cell lymphoma through reactive oxygen species

BACKGROUND

Vorinostat (SAHA) is a histone deacetylase inhibitor that has shown clinical efficacy against advanced cutaneous T-cell lymphoma (CTCL). However, only a subset of patients with CTCL (30-35%) respond to SAHA and the response is not always sustainable. Thus, understanding the mechanisms underlying evasive resistance in this cancer is an unmet medical need to improve the efficacy of current therapies.

PURPOSE

This study aims to identify factors contributing to resistance against SAHA in CTCL and ways to mitigate it.

METHODS AND RESULTS

In this study, we demonstrated that attenuated reactive oxygen species (ROS) induces the expression of interleukin (IL)-2Rα, one of the IL-2 receptors, which drives resistance to SAHA in CTCL. We also determined that cantharidin could overcome SAHA resistance to CTCL by blocking IL-2Rα-related signaling via ROS-dependent manner. Mechanistically, accelerated translation of IL-2Rα contributes to excessive IL-2Rα protein formation as a result of reduced ROS levels in SAHA-resistant CTCL. At the same time, amplified IL-2R signals are evidenced by strengthened interaction of IL-2Rβ with IL-2Rγ and Janus kinase/signal transducer and activator of transcription molecules, and by increased expression of protein kinase B (AKT)/mTOR and mitogen-activated protein kinase signaling. Moreover, cantharidin, an active constituent of Mylabris used in traditional Chinese medicine, markedly increased ROS levels, and thereby restrained IL-2Rα translation, resulting in suppression of downstream pathways in SAHA-resistant cells. Cantharidin is also found to synergize with SAHA and triggers SAHA-resistant cell death via IL-2R signaling both in vitro and in vivo.

CONCLUSION

Our study uncovers a novel molecular mechanism of acquired SAHA resistance and also suggests that using cantharidin is a potential approach to overcome CTCL therapy resistance. Our findings underlie the therapeutic potential of cantharidin in treating CTCL.

In vitro immune-depression and anti-inflammatory activities of cantharidin on gilthead seabream (Sparus aurata) leucocytes activated by λ-carrageenan

Cantharidin is a natural compound with known therapeutic applications in humans. The aim of this study was to investigate the in vitro effects of cantharidin on gilthead seabream (Sparus aurata) head kidney leucocytes (HKL) stimulated with λ-carrageenan. HKLs were incubated for 24 h with cantharidin (0, 2.5 and 5 μg mL-1) and λ-carrageenan (0 and 1000 μg mL-1). The results showed that HKL viability only decreased by 15.2% after incubated with 5 μg mL-1 of cantharidin and λ-carrageenan. Cantharidin increased the peroxidase activity of HKLs only when incubated in combination with λ-carrageenan. Besides this, cantharidin inhibited the respiratory burst and phagocytic activities. Furthermore, cantharidin induced morphological changes in HKLs (apoptotic and vacuolization signs) that were enhanced when incubated with λ-carrageenan. Considering the analysis of the selected gene expression studied in HKLs [NF-κB subunits (rela, relb, crel, nfkb1, nfkb2), proinflammatory cytokines (il1b, tnfa), anti-inflammatory cytokines (il10, tgfb) and caspases (casp1, casp3, casp8, casp9)], although λ-carrageenan up-regulated the expression of the proinflammatory gene il1b, λ-carrageenan and cantharidin down-regulated its expression in HKLs. In addition, cantharidin up-regulated casp3 and casp9 expression. The casp3 and casp9 gene expression was down-regulated while casp1 gene expression was up-regulated in HKLs incubated with both cantharidin and λ-carrageenan. All the effects of cantharidin are related to its inhibitory effect on protein phosphatases, which induce apoptosis at long exposure times, and minimize the effects of λ-carrageenan. The present results provide detailed insight into the immune-depressive and anti-inflammatory properties of cantharidin on immune cells, which could be of interest to the aquaculture sector.

The evidence framework of traditional Chinese medicine injection (Aidi injection) in controlling malignant pleural effusion: A clustered systematic review and meta-analysis

INTRODUCTION

Aidi injection (Aidi), a traditional Chinese medicine injection, is often practiced to control malignant pleural effusion (MPE).

OBJECTIVES

We performed a registered systematic review and meta-analysis (PROSPERO: CRD42022337611) to clarify the clinical role of Aidi in MPE, reveal optimal combinations of Aidi and chemical agents, their indications, therapeutic route and usage, and demonstrate their clinical effectiveness and safety.

METHODOLOGY

All randomized controlled trials (RCTs) about Aidi in controlling MPE were collected from Chinese and English databases (up to October 2022). We clustered them into multiple homogenous regimens, evaluated the risk-of-bias at outcome level using a RoB 2, extracted and pooled the data using meta-analysis or descriptive analysis, and finally summarized their evidence quality.

RESULTS

All 56 studies were clustered into intrapleural administration with Aidi alone or plus chemical agents, and intravenous administration with Aidi for MPE. Intrapleural administration with Aidi alone displayed similar clinical responses on Cisplatin (DDP) alone. Only administration with Aidi plus DDP significantly improved complete response and quality of life, and displayed a low pleurodesis failure, disease progression, hematotoxicity, gastrointestinal and hepatorenal toxicity. For patients with moderate to massive effusion, Karnofsky Performance Status score ≥ 50 or anticipated survival time ≥3 months, Aidi (50 ml to 80 ml each time, one time each week and three to eight times) plus DDP (20 to 30 mg, 40 to 50 mg, or 60 to 80 mg each time) significantly improved clinical responses. Most results had moderate to low quality.

CONCLUSIONS

Current evidences indicate that Aidi, a pleurodesis agent, plays an interesting clinical role in controlling MPE. Aidi plus DDP perfusion is a most commonly used regimen, which shows a significant improvement in clinical responses. These findings also provide an indication and possible optimal usage for rational drug use.

Astragalus polysaccharide promotes sheep satellite cell differentiation by regulating miR-133a through the MAPK/ERK signaling pathway

Astragalus polysaccharide (APS) possesses extensive biological activities, pharmacological effects, and anti-fatigue function. MiR-133a is a specifically expressed miRNA in skeletal muscle that participates in the regulation of myoblast proliferation and differentiation. However, little is known about the role of APS in the development of sheep skeletal muscle. In this study, we aimed to investigate the underlying mechanism of APS and miR-133a on the differentiation of sheep skeletal muscle satellite cells (SMSCs) and the regulatory relationship between APS and miR-133a. The results suggested that APS plays a positive regulatory role in the proliferation and differentiation of sheep SMSCs. Moreover, miR-133a significantly promotes SMSC differentiation and the activity of the MAPK/ERK signaling pathway. Importantly, we found that APS function requires the mediation of miR-133a in the differentiation of sheep SMSCs. Taken together, our results indicate that APS accelerates SMSC differentiation by regulating miR-133a via the MAPK/ERK signaling pathway in sheep.

Supramolecular self-assembled AIE molecules are used in the search for target proteins in norcantharidin

Norcantharidin (NCTD), a demethylated derivative of cantharidin, is an anticancer active component in traditional Chinese medicine. At present, the main methods for finding its target proteins are pharmacological methods and biophysical screening, which cannot achieve the purpose of efficient and accurate screening. Here we established a new analytical method for specific fishing and assisted imaging for norcantharidin target proteins. For the AIE supramolecule probe, the benzophenone azide (BPA) fluorescent nanoparticles with strong AIE properties were encapsulated in biocompatible DSPE-PEG that covalently coupled with NCTD (named BPA@NCTD NPs). The target proteins of NCTD can be captured by BPA@NCTD NPs, and then be detected to investigate the potential signaling pathways. The screened differential proteins were analysed through the protein and signaling pathway database, and multiple signaling pathways were obtained and verified. The mechanism of norcantharidin in inhibiting the migration and invasion of A549 cells through the P53 signaling pathway was confirmed by Western blot experiments. Our research showed that AIE supramolecule probe BPA@NCTD NPs has the dual functions of specific screening of A549 cells target proteins and biological imaging, which not only offers a good anti-fluorescence quenching ability for the dynamic imaging process of NCTD, but also provides a novel and efficient specific method for efficient analysis of target proteins and signal pathways.

Cantharidin and Its Analogue Norcantharidin Inhibit Metastasis-Inducing Genes S100A4 and MACC1

Colorectal cancer (CRC) is the third most prevalent and second deadliest cancer worldwide. In addition, metastasis directly causes up to 90% of all CRC deaths, highlighting the metastatic burden of the disease. Biomarkers such as S100A4 and MACC1 aid in identifying patients with a high risk of metastasis formation. High expression of S100A4 or MACC1 and to a greater extent the combination of both biomarkers is a predictor for metastasis and poor patient survival in CRC. MACC1 is a tumor-initiating and metastasis-promoting oncogene, whereas S100A4 has not been shown to initiate tumor formation but can, nevertheless, promote malignant tumor growth and metastasis formation. Cantharidin is a natural drug extracted from various blister beetle species, and its demethylated analogue norcantharidin has been shown in several studies to have an anti-cancer and anti-metastatic effect in different cancer entities such as CRC, breast cancer, and lung cancer. The impact of the natural compound cantharidin and norcantharidin on S100A4 and MACC1 gene expression, cancer cell migration, motility, and colony formation in vitro was tested. Here, for the first time, we have demonstrated that cantharidin and norcantharidin are transcriptional inhibitors of S100A4 and MACC1 mRNA expression, protein expression, and motility in CRC cells. Our results clearly indicate that cantharidin and, to a lesser extent, its analogue norcantharidin are promising compounds for efficient anti-metastatic therapy targeting the metastasis-inducing genes S100A4 and MACC1 for personalized medicine for cancer patients.

Strategies for Solubility and Bioavailability Enhancement and Toxicity Reduction of Norcantharidin

Cantharidin (CTD) is the main active ingredient isolated from Mylabris, and norcantharidin (NCTD) is a demethylated derivative of CTD, which has similar antitumor activity to CTD and lower toxicity than CTD. However, the clinical use of NCTD is limited due to its poor solubility, low bioavailability, and toxic effects on normal cells. To overcome these shortcomings, researchers have explored a number of strategies, such as chemical structural modifications, microsphere dispersion systems, and nanodrug delivery systems. This review summarizes the structure-activity relationship of NCTD and novel strategies to improve the solubility and bioavailability of NCTD as well as reduce the toxicity. This review can provide evidence for further research of NCTD.

In vitro effects of cantharidin on gilthead seabream (Sparus aurata) head-kidney leucocytes

Cantharidin is a toxic vesicant terpene used in folk and traditional medicine due to its various therapeutic effects. Since there are no previous data on the effect of cantharidin in fish, this study aimed to investigate the in vitro related-inflammatory effects of cantharidin in gilthead seabream (Sparus aurata L.) head-kidney leucocytes (HKLs). In the first experiment, the HKLs were incubated with 0, 5 and 10 μg mL^-1 of cantharidin for 24 h to delimit its possible toxic effects. In a second experiment, leucocytes were incubated with ranging concentrations from 0 to 10 μg mL^-1 for 3, 6, or 12 h. Cell viability was higher in acidophilic granulocytes than in monocytes/macrophages and lymphocytes. Cantharidin caused apoptosis as was evidenced by transmission electron microscopy. In addition, cantharidin produced a time- and dose-dependent decrease of respiratory burst and phagocytic activities in HKLs, while their peroxidase activity was increased at 24 h of incubation with 5 and 10 μg mL^-1 of cantharidin. Different changes in the gene expression were observed after incubation with cantharidin. While the gene expression of tnfa, il1b and crel was up-regulated in HKLs, the nfkb1 and igmh genes were down-regulated in comparison to the expression found in control HKLs. Present results offer a first view of the possible effects and action mechanisms of cantharidin in HKLs, as well as its implication in the inflammatory process, which could be of interest not only for basic research but also in the aquaculture sector.

Effects of Ulinastatin on Proliferation and Apoptosis of Breast Cancer Cells by Inhibiting the ERK Signaling Pathway

PURPOSE

To explore the effects of ulinastatin on the proliferation and apoptosis of breast cancer cells and the relevant mechanism of action.

METHODS

Breast cancer cells (MCF-7) were cultured and randomly divided into three groups, namely, control group, ulinastatin group, and ulinastatin+extracellular-regulated protein kinase (ERK) inhibitor group. Then, the Cell Counting Kit-8 (CCK-8) assay was carried out to detect the effect of ulinastatin on the viability of breast cancer cells. The effects of ulinastatin on the proliferation and apoptosis of breast cancer cells were determined via EdU staining and Hoechst 33258 staining assays, respectively. The messenger ribonucleic acid (mRNA) and protein expression levels of ERK and forkhead box O3 (FOXO3) in breast cancer cells were measured through reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting.

RESULTS

In comparison with the control group, the ulinastatin group displayed decreased viability of breast cancer cells, a decreased positive rate of 5-ethynyl-2'-deoxyuridine (EdU) staining, an increased positive rate of Hoechst 33258 staining, and reduced mRNA and protein levels of ERK and FOXO3 in breast cancer cells. Compared with those in the ulinastatin group, the viability of breast cancer cells was lowered, the positive rate of EdU staining was reduced, the positive rate of Hoechst 33258 staining was raised, and the mRNA and protein levels of ERK and FOXO3 in breast cancer cells clearly declined in the ulinastatin+ERK inhibitor group.

CONCLUSION

Ulinastatin inhibits the proliferation and promotes the apoptosis of breast cancer cells. The possible mechanism of action is associated with the suppression of the ERK signaling pathway.

Cantharidin downregulates PSD1 expression and inhibits autophagic flux in yeast cells

Cantharidin is a terpenoid compound of insect origin, naturally produced by male blister beetles as an anti-predatory mechanism. Cantharidin has anticancer properties, which are attributed to its ability to induce cell cycle arrest, DNA damage, MAPK signalling pathway and apoptosis. Cantharidin has been reported to induce apoptosis in triple-negative breast cancer cells by suppressing autophagy via downregulation of Beclin 1 expression and autophagosome formation. However, it remains unclear which stage of the autophagic pathway is targeted by cantharidin. Herein, we report that yeast cells are sensitive to cantharidin, and external supplementation of ethanolamine (ETA) ameliorates the cytotoxicity. In addition, cantharidin downregulates phosphatidylserine decarboxylase1 (PSD1) expression. We also report that cantharidin inhibits autophagic flux, and external administration of ETA could rescue this inhibition. Additionally, co-treatment with chloroquine sensitized the autophagy inhibitory effects of cantharidin. We conclude that yeast cells are sensitive to cantharidin due to inhibition of autophagic flux.

A disorder-related variant (E420K) of a PP2A-regulatory subunit (PPP2R5D) causes constitutively active AKT-mTOR signaling and uncoordinated cell growth

Functional genomic approaches have facilitated the discovery of rare genetic disorders and improved efforts to decipher their underlying etiology. PPP2R5D-related disorder is an early childhood onset condition characterized by intellectual disability, hypotonia, autism-spectrum disorder, macrocephaly, and dysmorphic features. The disorder is caused by de novo single nucleotide changes in PPP2R5D, which generate heterozygous dominant missense variants. PPP2R5D is known to encode a B'-type (B'56δ) regulatory subunit of a PP2A-serine/threonine phosphatase. To help elucidate the molecular mechanisms altered in PPP2R5D-related disorder, we used a CRISPR-single-base editor to generate HEK-293 cells in which a single transition (c.1258G>A) was introduced into one allele, precisely recapitulating a clinically relevant E420K variant. Unbiased quantitative proteomic and phosphoproteomic analyses of endogenously expressed proteins revealed heterozygous-dominant changes in kinase/phosphatase signaling. These data combined with orthogonal validation studies revealed a previously unrecognized interaction of PPP2R5D with AKT in human cells, leading to constitutively active AKT-mTOR signaling, increased cell size, and uncoordinated cellular growth in E420K-variant cells. Rapamycin reduced cell size and dose-dependently reduced RPS6 phosphorylation in E420K-variant cells, suggesting that inhibition of mTOR1 can suppress both the observed RPS6 hyperphosphorylation and increased cell size. Together, our findings provide a deeper understanding of PPP2R5D and insight into how the E420K-variant alters signaling networks influenced by PPP2R5D. Our comprehensive approach, which combines precise genome editing, isobaric tandem mass tag labeling of peptides generated from endogenously expressed proteins, and concurrent liquid chromatography-mass spectrometry (LC-MS³), also provides a roadmap that can be used to rapidly explore the etiologies of additional genetic disorders.

Antitumor potential of the protein phosphatase inhibitor, cantharidin, and selected derivatives

Cantharidin is a potent natural protein phosphatase monoterpene anhydride inhibitor secreted by several species of blister beetle, with its demethylated anhydride analogue, (S)-palasonin, occurring as a constituent of the higher plant Butea frondosa. Cantharidin shows both potent protein phosphatase inhibitory and cancer cell cytotoxic activities, but possible preclinical development of this anhydride has been limited thus far by its toxicity. Thus, several synthetic derivatives of cantharidin have been prepared, of which some compounds exhibit improved antitumor potential and may have use as lead compounds. In the present review, the potential antitumor activity, structure-activity relationships, and development of cantharidin-based anticancer drug conjugates are summarized, with protein phosphatase-related and other types of mechanisms of action discussed. Protein phosphatases play a key role in the tumor microenvironment, and thus described herein is also the potential for developing new tumor microenvironment-targeted cancer chemotherapeutic agents, based on cantharidin and its naturally occurring analogues and synthetic derivatives.

Noncanonical Cell Death Induction by Reassortant Reovirus

Triple-negative breast cancer (TNBC) constitutes 10 to 15% of all breast cancer and is associated with worse prognosis than other subtypes of breast cancer. Current therapies are limited to cytotoxic chemotherapy, radiation, and surgery, leaving a need for targeted therapeutics to improve outcomes for TNBC patients. Mammalian orthoreovirus (reovirus) is a nonenveloped, segmented, double-stranded RNA virus in the Reoviridae family. Reovirus preferentially kills transformed cells and is in clinical trials to assess its efficacy against several types of cancer. We previously engineered a reassortant reovirus, r2Reovirus, that infects TNBC cells more efficiently and induces cell death with faster kinetics than parental reoviruses. In this study, we sought to understand the mechanisms by which r2Reovirus induces cell death in TNBC cells. We show that r2Reovirus infection of TNBC cells of a mesenchymal stem-like (MSL) lineage downregulates the mitogen-activated protein kinase/extracellular signal-related kinase pathway and induces nonconventional cell death that is caspase-dependent but caspase 3-independent. Infection of different MSL lineage TNBC cells with r2Reovirus results in caspase 3-dependent cell death. We map the enhanced oncolytic properties of r2Reovirus in TNBC to epistatic interactions between the type 3 Dearing M2 gene segment and type 1 Lang genes. These findings suggest that the genetic composition of the host cell impacts the mechanism of reovirus-induced cell death in TNBC. Together, our data show that understanding host and virus determinants of cell death can identify novel properties and interactions between host and viral gene products that can be exploited for the development of improved viral oncolytics.IMPORTANCE TNBC is unresponsive to hormone therapies, leaving patients afflicted with this disease with limited treatment options. We previously engineered an oncolytic reovirus (r2Reovirus) with enhanced infective and cytotoxic properties in TNBC cells. However, how r2Reovirus promotes TNBC cell death is not known. In this study, we show that reassortant r2Reovirus can promote nonconventional caspase-dependent but caspase 3-independent cell death and that the mechanism of cell death depends on the genetic composition of the host cell. We also map the enhanced oncolytic properties of r2Reovirus in TNBC to interactions between a type 3 M2 gene segment and type 1 genes. Our data show that understanding the interplay between the host cell environment and the genetic composition of oncolytic viruses is crucial for the development of efficacious viral oncolytics.

Anticancer Attributes of Cantharidin: Involved Molecular Mechanisms and Pathways

Cancer is a preeminent threat to the human race, causing millions of deaths each year on the Earth. Traditionally, natural compounds are deemed promising agents for cancer treatment. Cantharidin (CTD)-a terpenoid isolated from blister beetles-has been used extensively in traditional Chinese medicines for healing various maladies and cancer. CTD has been proven to be protein phosphatase 2A (PP2A) and heat shock transcription factor 1 (HSF-1) inhibitor, which can be potential targets for its anticancer activity. Albeit, it harbors some toxicities, its immense anticancer potential cannot be overlooked, as the cancer-specific delivery of CTD could help to rescue its lethal effects. Furthermore, several derivatives have been designed to weaken its toxicity. In light of extensive research, the antitumor activity of CTD is evident in both in vitro as well as in vivo cancer models. CTD has also proven efficacious in combination with chemotherapy and radiotherapy and it can also target some drug-resistant cancer cells. This mini-review endeavors to interpret and summarize recent information about CTD anticancer potential and underlying molecular mechanisms. The pertinent anticancer strength of CTD could be employed to develop an effective anticarcinogenic drug.

RNA-sequencing-based transcriptome analysis of cantharidin-induced myocardial injury

The cardiotoxicity of cantharidin has been well characterized, but the understanding of the underlying mechanism(s) is incomplete. To more fully understand the differentially expressed genes (DEGs) in cantharidin-induced myocardial injury, Sprague-Dawley rats were exposed to cantharidin (1.34 mg/kg or 2.67 mg/kg) for 24 h and then the heart was sampled for pathologic changes analysis and RNA-sequencing-based transcriptomic profiling. In addition, serum troponin T (TN-T) levels were also tested using the enzyme-linked immunosorbent assay method. The results showed that cantharidin could cause myocardial damage and elevated serum TN-T levels. The genes with a fold change ≥2 were considered as DEGs and we found 38 DEGs that were mainly enriched in eight pathways revealed by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The cellular component of gene ontology analysis showed that the DEGs were mostly enriched in the extracellular matrix. In conclusion, our present study demonstrated that cantharidin induces myocardial injury by multiple modulatory mechanisms, which provide new insights for further study of the pathophysiologic mechanism of cantharidin-induced myocardial injury.

Broussoflavonol B from Broussonetia kazinoki Siebold Exerts Anti-Pancreatic Cancer Activity through Downregulating FoxM1

Pancreatic cancer has a high mortality rate due to poor rates of early diagnosis. One tumor suppressor gene in particular, p53, is frequently mutated in pancreatic cancer, and mutations in p53 can inactivate normal wild type p53 activity and increase expression of transcription factor forkhead box M1 (FoxM1). Overexpression of FoxM1 accelerates cellular proliferation and cancer progression. Therefore, inhibition of FoxM1 represents a therapeutic strategy for treating pancreatic cancer. Broussoflavonol B (BF-B), isolated from the stem bark of Broussonetia kazinoki Siebold has previously been shown to inhibit the growth of breast cancer cells. This study aimed to investigate whether BF-B exhibits anti-pancreatic cancer activity and if so, identify the underlying mechanism. BF-B reduced cell proliferation, induced cell cycle arrest, and inhibited cell migration and invasion of human pancreatic cancer PANC-1 cells (p53 mutated). Interestingly, BF-B down-regulated FoxM1 expression at both the mRNA and protein level. It also suppressed the expression of FoxM1 downstream target genes, such as cyclin D1, cyclin B1, and survivin. Cell cycle analysis showed that BF-B induced the arrest of G0/G1 phase. BF-B reduced the phosphorylation of extracellular signal-regulated kinase ½ (ERK½) and expression of ERK½ downstream effector c-Myc, which regulates cell proliferation. Furthermore, BF-B inhibited cell migration and invasion, which are downstream functional properties of FoxM1. These results suggested that BF-B could repress pancreatic cancer cell proliferation by inactivation of the ERK/c-Myc/FoxM1 signaling pathway. Broussoflavonol B from Broussonetia kazinoki Siebold may represent a novel chemo-therapeutic agent for pancreatic cancer.

18-GA-Suc Modified Liposome Loading Cantharidin for Augmenting Hepatic Specificity: Preparation, Characterization, Antitumor Effects, and Liver-Targeting Efficiency

Cantharidin (CTD), a natural Chinese medicine constituent extracted from mylabris, is a potent drug against hepatocellular carcinoma. However, the clinical application of CTD was limited because of its toxicity and low solubility. In this work, a novel CTD-loaded liposome modified with 3-succinyl-30-stearyl glycyrrhetinic acid (18-GA-Suc-CTD-Lip) was prepared to enhance liver-targeting efficiency and antitumor activity. 18-GA-Suc-CTD-Lip and CTD-Lip were successfully prepared by film dispersion method and totally characterized. The antitumor effects in vitro were evaluated by cell proliferation inhibition assay, transwell assay, cell cycle analysis, and an apoptosis test. Pharmacokinetic and biodistribution were all investigated to precisely reveal liver-targeting efficiency of 18-GA-Suc-CTD-Lip in vivo. The IC₅₀ values of 18-GA-Suc-CTD-Lip in HepG2 (3.417 ± 0.165 nmol/L) and Huh-7 (4.478 ± 0.409 nmol/L) cells were much lower than that of CTD-Lip, indicating that antitumor effects of 18-GA-Suc-CTD-Lip were remarkable because of the modification of 18-GA-Suc. The maximum concentration in the liver of 18-GA-Suc-CTD-Lip (1.72 ± 0.14 μg/g) was more than twice CTD-Lip (0.75 ± 0.08 μg/g) at 30 min, illustrating that 18-GA-Suc-CTD-Lip possesses excellent liver-targeting efficiency. Conclusively, 18-GA-Suc-CTD-Lip could be a potential liver-targeting antitumor drug for hepatocellular carcinoma.

Integrin beta 4 (ITGB4) and its tyrosine-1510 phosphorylation promote pancreatic tumorigenesis and regulate the MEK1-ERK1/2 signaling pathway

Pancreatic cancer is the fourth leading cause of cancer death, with a 5-year survival rate of only 1–4%. Integrin-mediated cell adhesion is critical for the initiation, progression, and metastasis of cancer. In this study we investigated the role of integrin β4 (ITGB4) and its phosphorylation at tyrosine Y1510 (p-ITGB4-Y1510) in the tumorigenesis of pancreatic cancer. We analyzed the expression of ITGB4 and p-ITGB4-Y1510 in pancreatic cancer tissue and cell lines using immunohistochemistry, Western blot, or semi-quantitative reverse transcription PCR. ITGB4 and p-ITGB4-Y1510 were highly expressed in pancreatic cancer (n = 176) compared with normal pancreatic tissue (n = 171). High p-ITGB4-Y1510 expression correlated with local invasion and distant metastasis of pancreatic cancer, and high ITGB4 was significantly associated with poor survival of patients. Inhibition of ITGB4 by siRNA significantly reduced migration and invasion of PC-1.0 and AsPC-1 cells. Overexpression of the mutant ITGB4-Y1510A (a mutation of tyrosine to alanine at 1510 position) in PC-1.0 and AsPC-1 cells not only blocked the ITGB4 phosphorylation at Y1510 but also suppressed the expression of ITGB4 (p < 0.05 vs. wild-type ITGB4). The transfection of PC-1.0 and AsPC-1 cells with ITGB4-Y1510A significantly decreased the level of p-mitogen-activated protein kinase kinase (MEK)1 (T292) and p-extracellular signal-regulated kinase (ERK)1/2 but did not affect the level of p-MEK1 (T386) and p-MEK2 (T394). Overall, our study showed that ITGB4 and its phosphorylated form promote cell migration and invasion in pancreatic cancer and that p-ITGB4-Y1510 regulates the downstream MEK1-ERK1/2 signaling cascades. Targeting ITGB4 or its phosphorylation at Y1510 may be a novel therapeutic option for pancreatic cancer.

Cantharidin suppresses gastric cancer cell migration/invasion by inhibiting the PI3K/Akt signaling pathway via CCAT1

Cantharidin (CTD) is a traditional Chinese medicine that shows an anticancer effects in multiple types of cancer cells. However, the mechanism of CTD anti-cancer function in gastric cancer (GC) is still unclear. The aim of the present study was to investigate the underlying mechanism that CTD inhibits proliferation and migration through suppression of the PI3K/Akt signaling. CTD induced GC cell apoptosis and inhibited metastasis measured by CCK8 assays as well as wound healing assays and transwell assays. Mechanistic investigations suggested that CTD modulated the PI3K/Akt signaling via western-blot and quantitative q-PCR. In addition, we identified and confirmed CCAT1 as a novel direct target of CTD inhibited PI3K/AKt signaling expression. In conclusion, our results provide new point into the critical role of CTD in suppressing PI3K/Akt signaling via down-regulation of CCAT1, resulting in suppression GC cell growth and migration/invasion.

Nucleotide exchange factor SIL1 promotes the progress of breast cancer cells via regulating the cell cycle and apoptosis

Breast cancer, as one of the most malignant tumors, poses a serious threat to the lives of females. Nucleotide exchange factor SIL1 is an important regulator of endoplasmic reticulum function that might have a specific role in tumor progression. In this study, we aimed to investigate the effect of SIL1 on the proliferation, apoptosis, and metastasis of human breast cancer. SIL1-specific small interfering RNA was transfected into two breast cancer cell lines, MCF7 and MDA-MB-231, to generate SIL1 knockdown cells. Clone formation and Cell Counting Kit-8 assays were performed to determine cell proliferation. Wound healing and transwell assays were used to detect the cell migration and invasion, respectively. Cell cycle and apoptosis were determined by flow cytometry. The messenger RNA and protein levels of target genes were analyzed using quantitative real-time PCR and western blot. According to the results of TCGA and GTEx database analysis, we determined that SIL1 was overexpressed in 1085 breast cancer samples compared with 291 normal samples. Knockdown of SIL1 inhibited the proliferation, migration, and invasion of MCF7 and MDA-MB-231 cells, accordingly. The cell cycle was blocked at the G1 phase following transfection of SIL1-specific small interfering RNA through the inhibition of Cyclin D1, CDK4, and CDK6. SIL1 knockdown induced apoptosis and also promoted the activity of Caspase9 and Bax. Furthermore, SIL1 was able to promote phosphorylation of ERK1/2. Based on these results, SIL1 might act as an oncogene and accelerate the progression of human breast cancer.

Anticancer Effect of the Ethyl Acetate Fraction from Orostachys japonicus on MDA-MB-231 Human Breast Cancer Cells through Extensive Induction of Apoptosis, Cell Cycle Arrest, and Antimetastasis

The antibreast cancer activities of the ethyl acetate fraction from Orostachys japonicus (OJEF) were investigated in MDA-MB-231 human breast cancer cells through WST assay, DAPI staining, flow cytometry analysis, and western blotting. OJEF effectively inhibited MDA-MB-231 cells by inducing apoptosis via intrinsic, extrinsic, and endoplasmic reticulum (ER) stress response pathways, cell cycle arrest at the G1/S phase, and antimetastasis including inhibition of tight junction, adherens junction, invasion, and migration. The MAPK family-mediated upstream signal transduction through p-p38 and p-ERK was considered to affect the downstream signal transduction including induction of apoptosis, cell cycle arrest, and antimetastasis. In conclusion, we executed an integrated study on the anticancer activities of OJEF, which extensively induced apoptosis, cell cycle arrest, and antimetastasis in estrogen-independent MDA-MB-231 human breast cancer cells known to be liable to metastasize.

Sophoraflavanone G from Sophora flavescens induces apoptosis in triple-negative breast cancer cells

BACKGROUND

A compound isolated from Sophora flavescens-sophoraflavanone G (SG)-showed anti-tumor and anti-inflammatory properties. We previously demonstrated that SG promoted apoptosis in human leukemia HL-60 cells. In the present study, we investigated the effects of SG on apoptosis in human breast cancer MDA-MB-231 cells, and explored the underlying molecular mechanisms.

METHODS

MDA-MB-231 cells were treated with various SG concentrations, and cell viability was evaluated by MTT assay. Apoptotic signal proteins were detected by western blotting, and cell apoptosis was assessed using flow cytometry.

RESULTS

Our results demonstrated that SG induced nuclear condensation, DNA fragmentation, reactive oxygen species production, and increased cell apoptosis in MDA-MB-231 cells. SG also suppressed migration and invasion, likely via blockage of the MAPK pathway. In the apoptotic signaling pathway, SG increased cleaved caspase-8, caspase-3, and caspase-9. SG treatment also decreased Bcl-2 and Bcl-xL expression, increased Bax expression, and prompted release of more cytochrome c from mitochondria to the cytoplasm in MDA-MB-231 cells.

CONCLUSION

Overall, our findings suggest that SG might increase apoptosis, and decrease migration and invasion, in MDA-MB-231 cells through suppression of a MAPK-related pathway.

Cantharidin Inhibits Anti-Apoptotic Bcl-2 Family Proteins and Induces Apoptosis in Human Osteosarcoma Cell Lines MG-63 and MNNG/HOS via Mitochondria-Dependent Pathway

Background

Cantharidin (CTD) is one of the major active ingredients of blister beetles and has significant antitumor activity in many cancer cell lines. The aim of our study was to evaluate the effect of CTD on the apoptosis of human osteosarcoma cells MG-63 and MNNG/HOS, and to explore the possible molecular mechanism.

Material/Methods

Osteosarcoma cells MG-63 and MNNG/HOS were treated with varying concentrations of CTD. The proliferation inhibition of cells was detected by MTS. Flow cytometry and Hoechst 33258 staining were used to determine cell cycle arrest and apoptosis, and apoptosis-related protein levels were analyzed by Western blotting.

Results

Our current findings suggest that CTD could inhibit the proliferation of these 2 osteosarcoma cells. The cells treated with CTD showed an obvious apoptotic morphology, and CTD promoted cells apoptosis in a dose-dependent manner. In addition, cantharidin-induced apoptosis was accompanied by increased expression of Bax and PARP and decreased expression of Bcl-2, p-Akt, and p-Cdc2.

Conclusions

CTD accelerates the apoptosis of MG-63 and MNNG/HOS cells in a concentration-dependent manner through the mitochondria-dependent pathway, suggesting that use of CTD is a novel approach for the treatment of osteosarcoma.