Dihydroartemisinin exhibits antitumor activity toward hepatocellular carcinoma in vitro and in vivo

Target prediction and potential application of dihydroartemisinin on hepatocarcinoma treatment

With high incidence of hepatocarcinoma and limited effective treatments, most patients suffer in pain. Antitumor drugs are single-targeted, toxicity, causing adverse side effects and resistance. Dihydroartemisinin (DHA) inhibits tumor through multiple mechanisms effectively. This study explores and evaluates safety and potential mechanism of DHA towards human hepatocarcinoma based on network pharmacology in a comprehensive way. Adsorption, distribution, metabolism, excretion, and toxicity (ADMET) properties of DHA were evaluated with pkCSM, SwissADME, and ADMETlab. Potential targets of DHA were obtained from SwissTargetPrediction, Drugbank, TargetNET, and PharmMapper. Target gene of hepatocarcinoma was obtained from OMIM, GeneCards, and DisGeNET. Overlapping targets and hub genes were identified and analyzed for Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome pathway. Molecular docking was utilized to investigate the interactions sites and hydrogen bonds. Cell counting kit-8 (CCK8), wound healing, invasion, and migration assays on HepG2 and SNU387 cell proved DHA inhibits malignant biological features of hepatocarcinoma cell. DHA is safe and desirable for clinical application. A total of 131 overlapping targets were identified. Biofunction analysis showed targets were involved in kinase activity, protein phosphorylation, intracellular reception, signal transduction, transcriptome dysregulation, PPAR pathway, and JAK-STAT signaling axis. Top 9 hub genes were obtained using MCC (Maximal Clique Centrality) algorithm, namely CDK1, CCNA2, CCNB1, CCNB2, KIF11, CHEK1, TYMS, AURKA, and TOP2A. Molecular docking suggests that all hub genes form a stable interaction with DHA for optimal binding energy were all less than - 5 kcal/mol. Dihydroartemisinin might be a potent and safe anticarcinogen based on its biological safety and effective therapeutic effect.

Anticancer Activity and Molecular Mechanisms of an Ursodeoxycholic Acid Methyl Ester-Dihydroartemisinin Hybrid via a Triazole Linkage in Hepatocellular Carcinoma Cells

Hepatocellular carcinoma is the third most common cause of cancer-related death according to the International Agency for Research on Cancer. Dihydroartemisinin (DHA), an antimalarial drug, has been reported to exhibit anticancer activity but with a short half-life. We synthesized a series of bile acid-dihydroartemisinin hybrids to improve its stability and anticancer activity and demonstrated that an ursodeoxycholic-DHA (UDC-DHA) hybrid was 10-fold more potent than DHA against HepG2 hepatocellular carcinoma cells. The objectives of this study were to evaluate the anticancer activity and investigate the molecular mechanisms of UDCMe-Z-DHA, a hybrid of ursodeoxycholic acid methyl ester and DHA via a triazole linkage. We found that UDCMe-Z-DHA was even more potent than UDC-DHA in HepG2 cells with IC₅₀ of 1 μM. Time course experiments and stability in medium determined by cell viability assay as well as HPLC-MS/MS analysis revealed that UDCMe-Z-DHA was more stable than DHA, which in part accounted for the increased anticancer activity. Mechanistic studies revealed that UDCMe-Z-DHA caused G0/G1 arrest and induced reactive oxygen species (ROS), mitochondrial membrane potential loss and autophagy, which may in turn lead to apoptosis. Compared to DHA, UDCMe-Z-DHA displayed much lower cytotoxicity toward normal cells. Thus, UDCMe-Z-DHA may be a potential drug candidate for hepatocellular carcinoma.

Dihydroartemisinin synergistically enhances the cytotoxic effects of oxaliplatin in colon cancer by targeting the PHB2-RCHY1 mediated signaling pathway

Dihydroartemisinin (DHA) has recently attracted increasing attention for its low toxicity and high antitumor activity. DHA has been reported to have synergistic anticancer effects with a variety of drugs in the clinic; however, the molecular mechanism by which DHA inhibits tumorigenesis and improves oxaliplatin cytotoxicity in colon cancer cells is still not well understood. In this study, we found that DHA can inhibit cell proliferation and colony formation in a dose-dependent manner. Prohibitin 2 (PHB2) is a potential target by which DHA exerts its antitumor and cytotoxic effects. The function and molecular mechanism of PHB2 in colon cancer tumorigenesis were fully studied to determine the regulatory mechanism between DHA and PHB2. We found that PHB2, a mitochondrial inner membrane scaffold protein, has a higher expression level in colon cancer tissues than in adjacent nontumor tissues and is mainly localized in mitochondria. Overexpression of PHB2 can promote cell proliferation and colony formation in vitro and accelerate tumor growth in vivo. We also found that the expression level of PHB2 was inversely related to the cytotoxicity of DHA and oxaliplatin in colon cancer cells. The molecular mechanism of PHB2 in tumorigenesis and cancer therapy was further studied. The results showed that 20 μM DHA can downregulate PHB2 expression in a ubiquitylation-dependent manner and subsequently block PHB2-induced RCHY1 upregulation and p53 and p21 downregulation. In this process, RCHY1 is necessary for PHB2 to play a tumor-promoting role. Thus, PHB2 and RCHY1 are effective targets for colon cancer therapy, and DHA has synergistic anticancer effects with oxaliplatin via promoting PHB2 degradation in colon cancer cells.

Dihydroartemisinin inhibited the Warburg effect through YAP1/SLC2A1 pathway in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) was the third most common cause of cancer death. But it has only limited therapeutic options, aggressive nature, and very low overall survival. Dihydroartemisinin (DHA), an anti-malarial drug approved by the Food and Drug Administration (FDA), inhibited cell growth in HCC. The Warburg effect was one of the ten new hallmarks of cancer. Solute carrier family 2 member 1 (SLC2A1) was a crucial carrier for glucose to enter target cells in the Warburg effect. Yes-associated transcriptional regulator 1 (YAP1), an effector molecule of the hippo pathway, played a crucial role in promoting the development of HCC. This study sought to determine the role of DHA in the SLC2A1 mediated Warburg effect in HCC. In this study, DHA inhibited the Warburg effect and SLC2A1 in HepG2215 cells and mice with liver tumors in situ. Meanwhile, DHA inhibited YAP1 expression by inhibiting YAP1 promoter binding protein GA binding protein transcription factor subunit beta 1 (GABPB1) and cAMP responsive element binding protein 1 (CREB1). Further, YAP1 knockdown/knockout reduced the Warburg effect and SLC2A1 expression by shYAP1-HepG2215 cells and Yap1^LKO mice with liver tumors. Taken together, our data indicated that YAP1 knockdown/knockout reduced the SLC2A1 mediated Warburg effect by shYAP1-HepG2215 cells and Yap1^LKO mice with liver tumors induced by DEN/TCPOBOP. DHA, as a potential YAP1 inhibitor, suppressed the SLC2A1 mediated Warburg effect in HCC.

Network Pharmacology-Based Exploration on the Intervention of Qinghao Biejia Decoction on the Inflammation-Carcinoma Transformation Process of Chronic Liver Disease via MAPK and PI3k/AKT Pathway

Chronic liver disease(CLD) is a slow-developing and long-term disease that can cause serious damage to the liver. Thus far, it has been associated with viral hepatitis, non-alcoholic fatty liver disease(NAFLD), alcoholic liver disease(ALD), hepatic fibrosis(HF), liver cirrhosis (LC), and liver cancer. Qinghao Biejia Decoction (QBD) is a classic ancient Chinese herbal prescription with strong immune-enhancing, anti-inflammatory, and anti-tumor effects. In this study, we used a network pharmacology approach to investigate the molecular mechanisms of QBD in the inflammation-carcinoma transformation process of chronic liver disease. Two key drug targets, MAPK1 and PIK3CA, were screened using network pharmacology and molecular docking techniques, revealing dihydroartemisinin, artesunate, 12-O-Nicotinoylisolineolone, caffeic acid, and diincarvilone A as active ingredients involved in QBD mechanisms. The main signaling pathways involved were the PI3K-AKT signaling pathway and MAPK signaling pathway. In summary, our results indicated that QBD affects the inflammatory transformation of chronic liver disease through MAPK1 and PIK3CA and signaling pathways MAPK and PI3K/AKT. These data provide research direction for investigating the mechanisms underlying the inflammation-carcinoma transformation process in QBD for chronic liver disease.

The Effects of Qinghao-Kushen and Its Active Compounds on the Biological Characteristics of Liver Cancer Cells

Background and Aims. Artemisia annua (Qinghao) and Sophora flavescens (Kushen) are traditional Chinese medicines (TCMs). They are widely used in disease therapy, including hepatocellular carcinoma (HCC). However, their key compounds and targets for HCC treatment are unclear. This article mainly analyzed the vital active compounds and the mechanism of Qinghao-Kushen acting on HCC. Methods. First, we chose a traditional Chinese medicine, which has an excellent clinical effect on HCC by network meta-analysis. Then, we composed the Qinghao-Kushen herb pair and prepared the medicated serum. The active compounds of Qinghao-Kushen were verified by the LC-MS method. Next, we detected key targets from PubChem, SymMap, SwissTargetPrediction, DisGeNET, and GeneCards databases. Subsequently, the mechanism of Qinghao-Kushen was predicted by network pharmacology strategy and primarily examined in HuH-7 cells, HepG2 cells, and HepG2215 cells. Results. The effect of the Qinghao-Kushen combination was significantly better than that of single Qinghao or single Kushen in HepG2 and HuH-7 cells. Qinghao-Kushen increased the expression of activated caspase-3 protein than Qinghao or Kushen alone in HepG2 and HepG2215 cells. Network analyses and the LC-MS method revealed that the pivotal compounds of Qinghao-Kushen were matrine and scopoletin. GSK-3β was one of the critical molecules related to Qinghao-Kushen. We confirmed that Qinghao-Kushen and matrine-scopoletin decreased the expression of GSK-3β in HepG2 cells while increased GSK-3β expression in HepG2215 cells. Conclusions. This work not only illustrated that the practical components of Qinghao-Kushen on HCC were matrine and scopoletin but shed light on the inhibitory of Qinghao-Kushen and matrine-scopoletin on liver cancer cells. Moreover, Qinghao-Kushen and matrine-scopoletin had a synergistic effect over the drug alone in HuH-7, HepG2, or HepG2215 cells. GSK-3β may be a potential target for HCC therapy.

Dihydroartemisinin promoted FXR expression independent of YAP1 in hepatocellular carcinoma

Loss of FXR, one of bile acid receptors, enlarged livers. Yes-associated protein 1 (YAP1), a dominant oncogene, promotes hepatocellular carcinoma (HCC). However, the relationship between FXR and YAP1 was unspecified in bile acid homeostasis in HCC. Here, we used TIMER2.0, the Cancer Genome Atlas (TCGA) Database, and Kaplan-Meier Plotter Database and discovered that FXR was positively correlated with better prognosis in liver cancer patients. Our previous research showed that dihydroartemisinin (DHA) inhibited cell proliferation in HepG2 and HepG22215 cells. However, the relationship of YAP1 and the bile acid receptor FXR remains elusive during DHA treatment. Furthermore, we showed that DHA improved FXR and reduced YAP1 in the liver cancer cells and mice. Additionally, the expression of nucleus protein FXR was enhanced in Yap1^LKO mice with liver cancer. DHA promoted the expression level of whole and nuclear protein FXR independent of YAP1 in Yap1^LKO mice with liver cancer. DHA declined cholesterol 7α-hydroxylase, but not sterol 27-hydroxylase, and depressed cholic acid and chenodeoxycholic acid of liver tissue in Yap1^LKO mice with liver cancer. Generally, our results suggested that DHA improved FXR and declined YAP1 to suppress bile acid metabolism. Thus, we suggested that FXR acted as a potential therapeutic target in HCC.

Dihydroartemisinin ameliorates retinal vascular dysfunction in diabetes mellitus via the FASN/Kmal-mTOR/SREBP1 feedback loop

Microvascular dysfunction is the primary aetiology of visual impairment caused by diabetic retinopathy (DR). Dihydroartemisinin (DHA), the active metabolite of the antimalarials artemisinins, exhibits antiangiogenic properties in numerous diseases. Here, we investigated the function and mechanisms of DHA as a vasculoprotective agent in DR. DHA exerted its protective effect on vascular injuries in diabetic mice and inhibited cell proliferation and tube formation in human retinal microvascular endothelial cells by decreasing the level of fatty acid synthase (FASN), enhancing the malonylation of mechanistic target of rapamycin (mTOR) at lysine 1218 (K1218) and attenuating the activation of mTOR complex 1 (mTORC1). Impressively, a chemosynthetic small interfering RNA against FASN and mutagenesis of K1218 of mTOR showed therapeutic potential in suppressing cell proliferation and tube formation induced by high glucose. Notably, suppression of mTORC1 kinase activity further inhibited FASN by reducing p70S6K phosphorylation to subsequently reduce the expression of sterol regulatory element binding protein 1, which interacted directly with the FASN promoter at nucleotide positions -64 and -55. In conclusion, our study elucidated the promising effects of FASN and malonylation on vascular injuries of DR and indicated the great potential of DHA as a therapeutic approach.

Targeted Lipid Nanoparticles Encapsulating Dihydroartemisinin and Chloroquine Phosphate for Suppressing the Proliferation and Liver Metastasis of Colorectal Cancer

Antimalarial drugs Dihydroartemisinin (DHA) and chloroquine phosphate (CQ) exhibit evident anti-cancer activity, particularly as combination therapy. DHA and CQ combination therapy has been proved to exhibit higher cytotoxic effect in tumor cells and lower toxicity to normal cells than combination of artemisinin derivatives (ARTs) and anticancer chemotherapy drugs. However, different physiochemical properties of DHA and CQ, leading to distinctive in vivo outcomes, considerably limited their synergistic effect in cancer treatment. Herein, we developed a lipid nanoparticle (LNP) for co-delivery of DHA and CQ to inhibit proliferation and metastasis of colorectal cancer. Considering the beneficial effects of acid/reactive oxide species (ROS)-sensitive phospholipids and targeting ligands for colorectal cancer cells, an RGD peptide-modified pH/ROS dual-sensitive LNP loaded with DHA and CQ (RLNP/DC) was prepared. It exhibited optimal cytotoxicity and suppression of invasion and metastasis in HCT116 cells in vitro, attributable to irreversible upregulation of intracellular ROS levels, downregulation of VEGF expression, and upregulation of paxillin expression. A mouse model of orthotopic metastasis of colorectal cancer was established to evaluate anti-proliferation and anti-metastasis effects of RLNP/DC in vivo. Thus, an optimized nanoplatform for DHA and CQ combination therapy was developed in this study that offered potential antitumor efficacy against colorectal cancer.

Chemical hybridization of sulfasalazine and dihydroartemisinin promotes brain tumor cell death

Gliomas are primary brain tumors with still poor prognosis for the patients despite a combination of cytoreduction via surgery followed by a radio-chemotherapy. One strategy to find effective treatment is to combine two different compounds in one hybrid molecule via linker to add to or at best potentiate their impact on malignant cells. Here, we report on the effects of a newly synthesized hybrid of sulfasalazine (SAS) and dihydroartemisinin (DHA), called AC254. In previous studies, both SAS and DHA have already proved to have anti-tumor properties themselves and to have sensitizing respectively potentiating effects on other treatments against malignant tumors. We investigated the impact of individual drugs SAS and DHA, their 1:1 combination and a novel SAS-DHA hybrid compound (AC254) on rodent and human glioma cells. In our study SAS alone showed no or only a mild effect on glioma, whereas DHA led to a significant reduction of cell viability in a dose-dependent manner. Next we compared the efficacy of the hybrid AC254 to the combinational treatment of its parent compounds SAS and DHA. The hybrid was highly efficient in combating glioma cells compared to single treatment strategies regarding cell viability and cell death. Interestingly, AC254 showed a remarkable advantage over the combinational treatment with both parent compounds in most used concentrations. In addition to its reduction of tumor cell viability and induction of cell death, the hybrid AC254 displayed changes in cell cycle and reduction of cell migration. Taken together, these results demonstrate that clinically established compounds such as SAS and DHA can be potentiated in their anti-cancer effects by chemical hybridization. Thus, this concept provides the opportunity to devise new effective chemotherapeutic agents.

Dihydroartemisinin triggers ferroptosis in primary liver cancer cells by promoting and unfolded protein response‑induced upregulation of CHAC1 expression

Dihydroartemisinin (DHA), an artemisinin derivate, has been investigated as a potential antitumor drug in primary liver cancer (PLC). Ferroptosis is a form of iron-dependent cell death that can be driven by lipid peroxidation inducers. The present study aimed to determine whether and how DHA could promote the death of PLC cells by inducing ferroptosis. In total, four PLC cell lines with different p53 statuses, including Hep3B (p53 null), Huh7 (p53 mutant), PLC/PRF/5 (p53 mutant) and HepG2 (p53 wild-type), were treated with various concentrations of DHA. The effects of DHA on all three branches of the unfolded protein response (UPR) were evaluated. To deactivate the UPRs, small interfering RNA was used to knockdown the expression of activating transcription factor (ATF)4, X-box binding protein 1 (XBP1) or ATF6 in PLC cells. The effect of DHA on the promoter activity of Chac glutathione specific γ-glutamylcyclotransferase 1 (CHAC1) was evaluated using a dual luciferase reporter assay. The results revealed that DHA-induced death in PLC cells was irrelevant of the p53 status. PLC cells exposed to DHA displayed classic features of ferroptosis, such as increased lipid reactive oxygen species and malondialdehyde levels, an iron overload, and decreased activity or expression of glutathione (GSH), glutathione peroxidase 4, solute carrier family (SLC) 7 member 11 and SLC family 3 member 2. The antitumor effects of DHA in PLC cells were significantly weakened by two typical ferroptosis inhibitors, ferrostatin-1 and deferoxamine mesylate salt, whereas the antitumor effects were augmented following iron overload. Furthermore, DHA activated all three branches of the UPR (eukaryotic translation initiation factor 2 α kinase 3/eukaryotic translation initiation factor 2A/ATF4, inositol-requiring transmembrane kinase/endoribonuclease 1α/XBP1 and ATF6 branches) in vitro. Notably, DHA-induced ferroptosis was significantly attenuated following the knockdown of ATF4, XBP1 or ATF6 expression. In addition, the promoter activity of CHAC1, a gene capable of degrading GSH, was enhanced by DHA, but weakened when the aforementioned three UPR transcription factors were knocked down. In conclusion, the findings of the present study suggested that DHA may effectively induce ferroptosis in PLC cells through the activation of anti-survival UPRs and the upregulation of CHAC1 expression.

Anti-malarial drug: the emerging role of artemisinin and its derivatives in liver disease treatment

Artemisinin and its derivatives belong to a family of drugs approved for the treatment of malaria with known clinical safety and efficacy. In addition to its anti-malarial effect, artemisinin displays anti-viral, anti-inflammatory, and anti-cancer effects in vivo and in vitro. Recently, much attention has been paid to the therapeutic role of artemisinin in liver diseases. Several studies suggest that artemisinin and its derivatives can protect the liver through different mechanisms, such as those pertaining to inflammation, proliferation, invasion, metastasis, and induction of apoptosis and autophagy. In this review, we provide a comprehensive discussion of the underlying molecular mechanisms and signaling pathways of artemisinin and its derivatives in treating liver diseases. Further pharmacological research will aid in determining whether artemisinin and its derivatives may serve as promising medicines for the treatment of liver diseases in the future.

Characterization of a Tumor-Microenvironment-Relevant Gene Set Based on Tumor Severity in Colon Cancer and Evaluation of Its Potential for Dihydroartemisinin Targeting

Colon cancer (COAD) is a leading cause of cancer mortality in the world. Most patients with COAD die as a result of cancer cell metastasis. However, the mechanisms underlying the metastatic phenotype of COAD remain unclear. Instead, particular features of the tumor microenvironment (TME) could predict adverse outcomes including metastasis in patients with COAD, and the role of TME in governing COAD progression is undeniable. Therefore, exploring the role of TME in COAD may help us better understand the molecular mechanisms behind COAD progression which may improve clinical outcomes and quality of patients. Here, we identified a Specific TME Regulatory Network including AEBP1, BGN, POST, and FAP (STMERN) that is highly involved in clinical outcomes of patients with COAD. Comprehensive in silico analysis of our study revealed that the STMERN is highly correlated with the severity of COAD. Meanwhile, our results reveal that the STMERN might be associated with immune infiltration in COAD. Importantly, we show that dihydroartemisinin (DHA) potentially interacts with the STMERN. We suggest that DHA might contribute to immune infiltration through regulating the STMERN in COAD. Taken together, our data provide a set of biomarkers of progression and poor prognosis in COAD. These findings could have potential prognostic and therapeutic implications in the progression of COAD.

Effects and Mechanisms of Anlotinib and Dihydroartemisinin Combination Therapy in Ameliorating Malignant Biological Behavior of Gastric Cancer Cells

BACKGROUND

Gastric Cancer (GC) is currently one of the major malignancies that threaten human lives and health. Anlotinib is a novel small-molecule that inhibits angiogenesis to exert antitumor effects. However, its function in gastric cancer is incompletely understood.

OBJECTIVE

The aim of the present study was to investigate the anti-tumor effects and molecular mechanisms of anlotinib combined with Dihydroartemisinin (DHA) in SGC7901 gastric cancer cells.

METHODS

Different concentrations of anlotinib and DHA were used to treat SGC7901 gastric cancer cells, after which cell proliferation was measured. Drug interactions of anlotinib and DHA were analyzed by the Chou-Talalay method with CompuSyn software. Proliferation, apoptosis, invasion, migration, and angiogenesis were measured using the Cell Counting Kit-8 (CCK8) assay, flow cytometry, Transwell invasion assays, scratch assays, and chicken Chorioallantoic Membrane (CAM) assays. Proliferation- associated protein (Ki67), apoptosis-related protein (Bcl-2), and Vascular Endothelial Growth Factor A (VEGF-A) were quantified by Western blotting.

RESULTS

The combination of 2.5 μmol/L of anlotinib and 5 of μmol/L DHA was highly synergistic in inhibiting cell growth, significantly increased the apoptosis rate and suppressed obviously the invasion and migration capability and angiogenesis of gastric cancer cells. In addition, the expression levels of Ki67, Bcl-2, and VEGF-A, as well as angiogenesis, were significantly decreased in the Combination of drugs compared with control and either drug alone.

CONCLUSION

The combination of anlotinib and DHA showed synergistic antitumor activity, suggesting their potential in treating patients with gastric cancer.

A Network Pharmacology Approach to Reveal the Underlying Mechanisms of Artemisia annua on the Treatment of Hepatocellular Carcinoma

Objective

To investigate the potential active ingredients and underlying mechanisms of Artemisia annua (AA) on the treatment of hepatocellular carcinoma (HCC) based on network pharmacology.

Methods

In the present study, we used a network pharmacological method to predict its underlying complex mechanism of treating HCC. First, we obtained relative compounds of AA based on the traditional Chinese medicine systems pharmacology (TCMSP) database and collected potential targets of these compounds by target fishing. Then, we built HCC-related targets target by the oncogenomic database of hepatocellular carcinoma (OncoDB.HCC) and biopharmacological network (PharmDB-K) database. Based on the matching results between AA potential targets and HCC targets, we built a protein-protein interaction (PPI) network to analyze the interactions among these targets and screen the hub targets by topology. Furthermore, the function annotation and signaling pathways of key targets were performed by Gene Oncology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis using DAVID tools. Finally, the binding capacity between active ingredients and key targets was validated by molecular docking.

Results

A total of 19 main active ingredients of AA were screened as target prediction; then, 25 HCC-related common targets were seeked out via multiple HCC databases. The areas of nodes and corresponding degree values of EGFR, ESR1, CCND1, MYC, EGF, and PTGS2 were larger and could be easily found in the PPI network. Furthermore, GO and KEGG enrichment analysis showed that these key targets were significantly involved in multiple biological processes and pathways which participated in tumor cell proliferation, apoptosis, angiogenesis, tumor invasion, and metastasis to accomplish the anti-HCC activity. The molecular docking analysis showed that quercetin could stably bind to the active pocket of EGFR protein 4RJ5 via LibDock.

Conclusion

The anticancer effects of AA on HCC were predicted to be associated with regulating tumor cell proliferation, apoptosis, angiogenesis, tumor invasion, and metastasis via various pathways such as the EGFR signaling pathway, ESR1 signaling pathway, and CCND1 signaling pathway. It is suggested that AA might be developed as a broad-spectrum antitumor drug based on its characteristics of multicomponent, multipath, and multitarget.

Dihydroartemisinin: A Potential Natural Anticancer Drug

Dihydroartemisinin (DHA) is an active metabolite of artemisinin and its derivatives (ARTs), and it is an effective clinical drug widely used to treat malaria. Recently, the anticancer activity of DHA has attracted increasing attention. Nevertheless, there is no systematic summary on the anticancer effects of DHA. Notably, studies have shown that DHA exerts anticancer effects through various molecular mechanisms, such as inhibiting proliferation, inducing apoptosis, inhibiting tumor metastasis and angiogenesis, promoting immune function, inducing autophagy and endoplasmic reticulum (ER) stress. In this review, we comprehensively summarized the latest progress regarding the anticancer activities of DHA in cancer. Importantly, the underlying anticancer molecular mechanisms and pharmacological effects of DHA in vitro and in vivo are the focus of our attention. Interestingly, new methods to improve the solubility and bioavailability of DHA are discussed, which greatly enhance its anticancer efficacy. Remarkably, DHA has synergistic anti-tumor effects with a variety of clinical drugs, and preclinical and clinical studies provide stronger evidence of its anticancer potential. Moreover, this article also gives suggestions for further research on the anticancer effects of DHA. Thus, we hope to provide a strong theoretical support for DHA as an anticancer drug.

p53 Enhances Artemisia annua L. Polyphenols-Induced Cell Death Through Upregulation of p53-Dependent Targets and Cleavage of PARP1 and Lamin A/C in HCT116 Colorectal Cancer Cells

Plant-derived natural polyphenols exhibit anticancer activity without showing any noticeable toxicities to normal cells. The aim of this study was to investigate the role of p53 on the anticancer effect of polyphenols isolated from Korean Artemisia annua L. (pKAL) in HCT116 human colorectal cancer cells. We confirmed that pKAL induced reactive oxygen species (ROS) production, propidium iodide (PI) uptake, nuclear structure change, and acidic vesicles in a p53-independent manner in p53-null HCT116 cells through fluorescence microscopy analysis of DCF/PI-, DAPI-, and AO-stained cells. The pKAL-induced anticancer effects were found to be significantly higher in p53-wild HCT116 cells than in p53-null by hematoxylin staining, CCK-8 assay, Western blot, and flow cytometric analysis of annexin V/PI-stained cells. In addition, expression of ectopic p53 in p53-null cells was upregulated by pKAL in both the nucleus and cytoplasm, increasing pKAL-induced cell death. Moreover, Western bot analysis revealed that pKAL-induced cell death was associated with upregulation of p53-dependent targets such as p21, Bax and DR5 and cleavage of PARP1 and lamin A/C in p53-wild HCT116 cells, but not in p53-null. Taken together, these results indicate that p53 plays an important role in enhancing the anticancer effects of pKAL by upregulating p53 downstream targets and inducing intracellular cell death processes.

Evaluation of the Anticancer Activity of a Bile Acid-Dihydroartemisinin Hybrid Ursodeoxycholic-Dihydroartemisinin in Hepatocellular Carcinoma Cells

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy in adults and accounts for 85-90% of all primary liver cancer. Based on the estimation by the International Agency for Research on Cancer in 2018, liver cancer is the fourth leading cause of cancer death globally. Dihydroartemisinin (DHA), the main active metabolite of artemisinin derivatives, is a well-known drug for the treatment of malaria. Previous studies have demonstrated that DHA exhibits antitumor effects toward a variety of human cancers and has a potential for repurposing as an anticancer drug. However, its short half-life is a concern and may limit the application in cancer therapy. We have reported that UDC-DHA, a hybrid of bile acid ursodeoxycholic acid (UDCA) and DHA, is ∼12 times more potent than DHA against a HCC cell line HepG2. In this study, we found that UDC-DHA was also effective against another HCC cell line Huh-7 with an IC₅₀ of 2.16 μM, which was 18.5-fold better than DHA with an IC₅₀ of 39.96 μM. UDC-DHA was much more potent than the combination of DHA and UDCA at 1:1 molar ratio, suggesting that the covalent linkage rather than a synergism between UDCA and DHA is critical for enhancing DHA potency in HepG2 cells. Importantly, UDC-DHA was much less toxic to normal cells than DHA. UDC-DHA induced G0/G1 arrest and apoptosis. Both DHA and UDC-DHA significantly elevated cellular reactive oxygen species generation but with different magnitude and timing in HepG2 cells; whereas only DHA but not UDC-DHA induced reactive oxygen species in Huh-7 cells. Depolarization of mitochondrial membrane potential was detected in both HepG2 and Huh-7 cells and may contribute to the anticancer effect of DHA and UDC-DHA. Furthermore, UDC-DHA was much more stable than DHA based on activity assays and high performance liquid chromatography-MS/MS analysis. In conclusion, UDC-DHA and DHA may exert anticancer actions via similar mechanisms but a much lower concentration of UDC-DHA was required, which could be attributed to a better stability of UDC-DHA. Thus, UDC-DHA could be a better drug candidate than DHA against HCC and further investigation is warranted.

Dihydroartemisinin inhibits the migration of esophageal cancer cells by inducing autophagy

Esophageal cancer (EC) is a complex gastrointestinal malignancy and its global incidence rate ranks 7th among all cancer types. Due to its aggressive nature and the potential for early metastasis, the survival rates of patients with EC are poor. Dihydroartemisinin (DHA) is the primary active derivative of artemisinin, and, as well as its use as an anti-malarial, DHA has also exhibited antitumor activity in various cancer models, such as cholangiocarcinoma, head and neck carcinoma, and hepatocellular carcinoma cells. However, the molecular mechanisms underlying the antitumor effect of DHA in the treatment of EC remains poorly understood. The results of the present study demonstrated that DHA significantly inhibited the migration of TE-1 and Eca-109 EC cells in a dose-dependent manner by activating autophagy. DHA treatment also significantly reversed epithelial-mesenchymal transition (EMT) by downregulating the EMT-associated markers, N-cadherin and vimentin, and upregulating the expression of E-cadherin. Mechanistically, DHA treatment decreased Akt phosphorylation and inhibited the Akt/mTOR signaling pathway, leading to the activation of autophagy. The levels of the autophagy-associated proteins were suppressed and DHA-mediated inhibition of migration in EC cells was reversed when an active form of Akt was overexpressed. In conclusion, the present study demonstrated the potential value of DHA in the treatment of EC, and revealed the underlying mechanism by which FDHA inhibits cellular migration.

Artemisinin and its derivatives: a promising cancer therapy

The world is experiencing a cancer epidemic and an increase in the prevalence of the disease. Cancer remains a major killer, accounting for more than half a million deaths annually. There is a wide range of natural products that have the potential to treat this disease. One of these products is artemisinin; a natural product from Artemisia plant. The Nobel Prize for Medicine was awarded in 2015 for the discovery of artemisinin in recognition of the drug's efficacy. Artemisinin produces highly reactive free radicals by the breakdown of two oxygen atoms that kill cancerous cells. These cells sequester iron and accumulate as much as 1000 times in comparison with normal cells. Generally, chemotherapy is toxic to both cancerous cells and normal cells, while no significant cytotoxicity from artemisinin to normal cells has been found in more than 4000 case studies, which makes it far different than conventional chemotherapy. The pleiotropic response of artemisinin in cancer cells is responsible for growth inhibition by multiple ways including inhibition of angiogenesis, apoptosis, cell cycle arrest, disruption of cell migration, and modulation of nuclear receptor responsiveness. It is very encouraging that artemisinin and its derivatives are anticipated to be a novel class of broad-spectrum antitumor agents based on efficacy and safety. This review aims to highlight these achievements and propose potential strategies to develop artemisinin and its derivatives as a new class of cancer therapeutic agents.

Self-assembled dihydroartemisinin nanoparticles as a platform for cervical cancer chemotherapy

Dihydroartemisinin (DHA) is a potent anti-cancer drug that has limited clinical applications due to poor water solubility and low bioavailability. We designed a biodegradable poly(ethylene glycol) methyl ether-poly(ε-caprolactone) (MPEG-PCL) micelle carrier for DHA using the self-assembly method. The DHA/MPEG-PCL nanoparticles were spherical with an average particle size of 30.28 ± 0.27 nm, and released the drug in a sustained manner in aqueous solution. The drug-loaded nanoparticles showed dose-dependent toxicity in HeLa cells by inducing cycle arrest and apoptosis. Furthermore, compared to free DHA, the DHA/MPEG-PCL nanoparticles showed higher therapeutic efficacy and lower toxicity in vivo, and significantly inhibited tumor growth and prolonged the survival of tumor-bearing nude mice. In addition, the tumor tissues of the DHA/MPEG-PCL-treated mice showed a marked decline in the in situ expression of proliferation and angiogenesis markers. Taken together, the self-assembled DHA/MPEG-PCL nanoparticles are a highly promising delivery system for targeted cancer treatment.

Dihydroartemisinin Prevents Progression and Metastasis of Head and Neck Squamous Cell Carcinoma by Inhibiting Polarization of Macrophages in Tumor Microenvironment

Background

Polarized M2 macrophages are an important type of tumor-associated macrophage (TAM), with roles in the growth, invasion, and migration of cancer cells in the tumor microenvironment. Dihydroartemisinin (DHA), a traditional Chinese medicine extract, has been shown to inhibit the progression and metastasis of head and neck squamous cell carcinoma (HNSCC); however, the effect of DHA on cancer prevention, and the associated mechanism, has not been investigated in the tumor microenvironment.

Materials and Methods

First, human Thp-1 monocytes were induced and differentiated into M2 macrophages using phorbol 12-myristate 13-acetate (PMA), interleukin-6 (IL-6), and interleukin-4 (IL-4). Induction success was confirmed by cell morphology evaluation, flow cytometry, and quantitative real-time polymerase chain reaction (qRT-PCR). Then, DHA was applied to interfere with M2 macrophage polarization, and conditioned medium (CM), including conditioned medium from M2 macrophages (M2-CM) and conditioned medium from M2 macrophages with DHA (M2-DHA-CM), was obtained. CM was applied to Fadu or Cal-27 cells, and its effects on cancer invasion, migration, and angiogenesis were evaluated using transwell, wound-healing, and tube formation assays, respectively. Finally, Western blotting was used to evaluate the relationship between signal transducer and activator of transcription 3 (STAT3) signaling pathway activation and M2 macrophage polarization.

Results

Human Thp-1 monocytes were successfully polarized into M2-like TAMs using PMA, IL-6, and IL-4. We found that M2-like TAMs promoted the invasion, migration, and angiogenesis of HNSCC cells; however, DHA significantly inhibited IL-4/IL-6-induced M2 macrophage polarization. Additionally, as DHA induced a decrease in the number of M2-like TAMs, M2-DHA-CM inhibited the induction of invasion, migration, and angiogenesis of Fadu and Cal-27 cells. Finally, DHA inhibited M2 macrophage polarization by blocking STAT3 pathway activation in macrophages.

Conclusion

DHA inhibits the invasion, migration, and angiogenesis of HNSCC by preventing M2 macrophage polarization via blocking STAT3 phosphorylation.

The effect of R547, a cyclin-dependent kinase inhibitor, on hepatocellular carcinoma cell death

Hepatocellular carcinoma (HCC) is the third main cause of cancer-related death. Cyclin-dependent kinases (CDKs) and their cyclin partners regulate the cell cycle. Since inhibition of CDKs gives some guiding ideas for cancer studies, we aimed to determine the possible effects of R547, a cyclin kinase 1-2-4 inhibitor, on proliferation and apoptotic mechanisms of Hep G2 cells (human) and H-4-II-E cells derived from rat HCC. We determined in vitro survival rates with MTT assay, apoptosis with flow cytometry, morphological changes with confocal microscopy, and ultrastructural changes by transmission electron microscopy. Cisplatin was used as a positive control. After 24 h of culture with 0.1, 1, 10, 50, and 100 µM doses of R547, the corresponding percentages of live Hep G2 cells were 101%, 94%, 93%, 89%, and 79% (P < 0.001), respectively. However, with the same R547 doses the live Hep G2 cell percentages were 92%, 101%, 53.6% (P <0 .01), 47.4% (P < 0.001), and 41% (P < 0.001), respectively, after 48 h. After 24 h of incubation with the same doses of R547, the survival percentages of live rat cells were 90%, 80% (P < 0.01), 63% (P < 0.001), 47% (P < 0.001), and 43% (P < 0.001), respectively. The percentages of surviving H-4-II-E cells were 96%, 85% (P < 0.01), 46% (P < 0.001), 44% (P < 0.001), and 45% (P < 0.01), respectively, after 48 h. Since R547 did not significantly affect Hep G2 cell survival in 24 h, experiments of apoptosis were carried out with H-4-II-E cells. The early apoptotic rates of 38% and 45% (P < 0.05 for both) after applications of 10 and 25 μM R547 (control: 4.1%), respectively, indicated that R547 has an apoptotic effect on H-4-II-E cells in 24 h. The apoptosis morphology at 24 h of treatment was clearly observed with microscopic examinations. According to our results, it is obvious that R547 has antiproliferative action when compared to cisplatin.

TMT-based proteomics analysis of the anti-hepatocellular carcinoma effect of combined dihydroartemisinin and sorafenib

Hepatocellular carcinoma (HCC), as the major primary liver cancer, is one of the most prevalent malignant diseases with a high mortality rate worldwide. Prior studies have demonstrated that dihydroartemisinin (DHA), the semisynthetic derivative of artemisinin, possesses anti-HCC activity. The multikinase inhibitor sorafenib has been approved for the treatment of HCC. However, the anti-HCC efficacy of DHA combined with sorafenib has not been reported. In this study, we confirmed the significantly enhanced anti-HCC efficacy of DHA in combination with sorafenib compared with that of each agent alone. Tandem Mass Tag (TMT) peptide labeling coupled with LC-MS/MS was used to quantify the proteins from the control, DHA, sorafenib, and DHA + sorafenib groups. In total, 532, 426, 628 differentially expressed proteins (fold change >1.20 or <0.83 and P-value <0.05) were determined by comparing DHA versus control, sorafenib versus control and DHA + sorafenib versus control groups, respectively. Moreover, optimized screening was performed, and 101 optimized differentially expressed proteins were identified. The results of functional analysis of the optimized differentially expressed proteins suggested that they were enriched in cell components such as membrane-bound vesicles, extracellular vesicles, and organelle lumens, and they were mainly involved in biological processes such as cellular component organization, response to stress, and response to chemicals; in addition, they were related to various molecular functions such as protein binding, chromatin binding and enzyme binding. KEGG pathway analysis showed that the optimized differentially expressed proteins were enriched in pyrimidine metabolism, RNA polymerase, base excision repair, and osteoclast differentiation. Protein-protein interaction (PPI) networks of some of the optimized upregulated proteins suggested that they might not only affect vitamin and fat digestion and absorption but may also be involved in tight junctions. In the PPI network, some of the optimized downregulated proteins were enriched in base excision repair, RNA polymerase, purine metabolism, pyrimidine metabolism and mucin type O-glycan biosynthesis. Overall, this research explored the anti-HCC efficacy of DHA combined with sorafenib by using the TMT-based quantitative proteomics technique and might facilitate the understanding of the related anti-HCC molecular mechanism.

Dihydroartemisinin inhibits HepG2.2.15 proliferation by inducing cellular senescence and autophagy

Dihydroartemisinin (DHA) has been reported to possess anti-cancer activity against many cancers. However, the pharmacologic effect of DHA on HBV-positive hepatocellular carcinoma (HCC) remains unknown. Thus, the objective of the present study was to determine whether DHA could inhibit the proliferation of HepG2.2.15 cells and uncover the underlying mechanisms involved in the effect of DHA on HepG2.2.15 cells. We found that DHA effectively inhibited HepG2.2.15 HCC cell proliferation both in vivo and in vitro. DHA also reduced the migration and tumorigenicity capacity of HepG2.2.15 cells. Regarding the underlying mechanisms, results showed that DHA induced cellular senescence by up-regulating expression levels of proteins such as p-ATM, p-ATR, γ-H₂AX, P53, and P21 involved in DNA damage response. DHA also induced autophagy (green LC3 puncta gathered together and LC3II/LC3I ratio increased through AKT-mTOR pathway suppression). Results also revealed that DHA-induced autophagy was not linked to senescence or cell death. TPP1 (telomere shelterin) overexpression could not rescue DHA-induced anticancer activity (cell proliferation). Moreover, DHA down-regulated TPP1 expression. Gene knockdown of TPP1 caused similar phenotypes and mechanisms as DHA induced phenotypes and mechanisms in HepG2.2.15 cells. These results demonstrate that DHA might inhibit HepG2.2.15 cells proliferation through inducing cellular senescence and autophagy.

Dihydroartemisinin-Bile Acid Hybridization as an Effective Approach to Enhance Dihydroartemisinin Anticancer Activity

A series of hybrid compounds based on natural products-bile acids and dihydroartemisinin-were prepared by different synthetic methodologies and investigated for their in vitro biological activity against HL-60 leukemia and HepG2 hepatocellular carcinoma cell lines. Most of these hybrids presented significantly improved antiproliferative activities with respect to dihydroartemisinin and the parent bile acid. The two most potent hybrids of the series exhibited a 10.5- and 15.4-fold increase in cytotoxic activity respect to dihydroartemisinin alone in HL-60 and HepG2 cells, respectively. Strong evidence that an ursodeoxycholic acid hybrid induced apoptosis was obtained by flow cytometric analysis and western blot analysis.

Dihydroartemisinin inhibits the proliferation of IgAN mesangial cells through the mTOR signaling pathway

IgA nephropathy (IgAN) is an autoimmune kidney disease and is the most prevalent form of glomerular kidney disease in China and worldwide. IgA immune complex deposition accompanied by mesangial cell proliferation and mesangial matrix expansion is the most basic pathological feature of IgAN. Dihydroartemisinin (DHA), an antimalarial drug, was recently reported to be effective in treating autoimmune diseases. However, its potential therapeutic role in IgAN is relatively unstudied. The aim of this study was to investigate the pharmacological effects and the underlying mechanisms of DHA in the treatment of IgAN. In this study, renal biopsy specimens were collected for immunohistochemistry. In vitro, 25 μg/ml concentrations of aggregated IgA1 (aIgA1) was used to construct the IgAN mesangial cell model. Stimulated human mesangial cells (HMCs) were treated for 24 h with DHA (0-15 μM) and were collected for western blot analyses. Cell proliferation was assessed by Cell Counting Kit 8 (CCK8) and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. In vitro, our results showed that DHA could downregulate the mammalian target of rapamycin/ribosomal protein S6 kinase beta-1 (mTOR/S6K1) signaling pathway, promote cell autophagy, and ameliorate cell proliferation in aIgA1-induced HMCs. The results suggested that DHA may represent a novel class of mTOR inhibitor and promote an anti-proliferation effect in IgAN HMCs, which provides an alternative approach for IgAN treatment.

Dihydroartemisinin Sensitizes Mutant p53 (R248Q)-Expressing Hepatocellular Carcinoma Cells to Doxorubicin by Inhibiting P-gp Expression

Mutant p53 (R248Q) induces doxorubicin (ADM) resistance in hepatocellular carcinoma (HCC). Dihydroartemisinin (DHA) can synergistically enhance anticancer effect of many chemotherapeutic agents. However, whether DHA could increase therapeutic efficacy of ADM in p53 (R248Q)-expressing HCC cells remains unknown. In the present study, we established mutant p53 (R248Q)-expressing Hep3B cells to study the effect and mechanism of DHA on ADM resistance and the synergistic effect of DHA with ADM. We found that P-gp was highly expressed in p53 (R248Q)-expressing Hep3B cells. As a result, cells expressing p53 (R248Q) displayed higher cell viability and lower cell apoptosis level upon ADM treatment. Meanwhile, phosphorylation levels of ERK1/2 and p65 were elevated in p53 (R248Q)-expressing Hep3B cells. However, combination of DHA and ADM treatment decreased cell viability and elevated cell apoptosis level in p53 (R248Q)-expressing Hep3B cells. Molecular dynamics simulations showed that DHA had the potential to bind with mutant p53 (R248Q) protein. Furthermore, DHA treatment decreased P-gp expression and inhibited phosphorylation levels of ERK1/2 and p65 in p53 (R248Q)-expressing Hep3B cells. Finally, DHA treatment could significantly reduce ADM efflux in p53 (R248Q)-expressing cells. Our results indicate that DHA could decrease P-gp expression via inhibiting the p53 (R248Q)-ERK1/2-NF-κB signaling pathway, which eventually confers sensitization of p53 (R248Q)-expressing HCC cells to ADM. Our study provides evidence for the potential application of DHA and ADM combination in treatment of mutant p53 (R248Q)-harbored HCC.

Naturally occurring anti-cancer compounds: shining from Chinese herbal medicine

Numerous natural products originated from Chinese herbal medicine exhibit anti-cancer activities, including anti-proliferative, pro-apoptotic, anti-metastatic, anti-angiogenic effects, as well as regulate autophagy, reverse multidrug resistance, balance immunity, and enhance chemotherapy in vitro and in vivo. To provide new insights into the critical path ahead, we systemically reviewed the most recent advances (reported since 2011) on the key compounds with anti-cancer effects derived from Chinese herbal medicine (curcumin, epigallocatechin gallate, berberine, artemisinin, ginsenoside Rg3, ursolic acid, silibinin, emodin, triptolide, cucurbitacin B, tanshinone I, oridonin, shikonin, gambogic acid, artesunate, wogonin, β-elemene, and cepharanthine) in scientific databases (PubMed, Web of Science, Medline, Scopus, and Clinical Trials). With a broader perspective, we focused on their recently discovered and/or investigated pharmacological effects, novel mechanism of action, relevant clinical studies, and their innovative applications in combined therapy and immunomodulation. In addition, the present review has extended to describe other promising compounds including dihydroartemisinin, ginsenoside Rh2, compound K, cucurbitacins D, E, I, tanshinone IIA and cryptotanshinone in view of their potentials in cancer therapy. Up to now, the evidence about the immunomodulatory effects and clinical trials of natural anti-cancer compounds from Chinese herbal medicine is very limited, and further research is needed to monitor their immunoregulatory effects and explore their mechanisms of action as modulators of immune checkpoints.

Artesunate and sorafenib: Combinatorial inhibition of liver cancer cell growth

An antimalarial medication, artesunate (Art), has exhibited promising anticancer effects with excellent tolerability in various types of cancer, suggesting that it has the potential to be used in combination with sorafenib (Sora) in hepatocellular carcinoma (HCC) treatment. To determine the potency of this combination, the present study attempted to quantitatively measure the dose-effect relationship of each drug alone and in combination in liver cancer cells in vitro using Calcusyn software. Cell growth inhibition was determined using the CyQUANT proliferation assay in two liver cancer cell lines, HepG2 and Huh7. Drug combination and reduction indices and isobologram plots were used to assess drug interactions. Cell apoptosis was evaluated by measurements of the proportion of cells in the sub G₀/G₁ phase of the cell cycle, and determination of protein expression levels of cleaved poly ADP ribose polymerase and caspase-9. Additionally, a cell migration assay was conducted using Essen ImageLock plates with an IncuCyte Zoom imaging system. The results of the present study revealed that the inhibitory effect of Sora on cell growth was synergistically enhanced by the combination with Art in HepG2 and Huh7 cells. The combination index and dose reduction index were specific to each cell line. Furthermore, combination at a fixed ratio presented mutual enhancement with respect to apoptosis induction and suppression of in vitro liver cancer cell migration. Therefore, considering the low toxicity and well-defined clinical characteristics of Art, combination of Sora and Art may present an attractive therapeutic option in the development of clinical trials for HCC treatment.

Dihydroartemisinin suppresses glycolysis of LNCaP cells by inhibiting PI3K/AKT pathway and downregulating HIF-1α expression

AIMS

Dihydroartemisinin (DHA) exhibits potential anticancer activity. However, the biological functions of DHA in prostate cancer remain largely unexplored. In this study, we aim to investigate the anti-proliferative effect and glycolysis regulation of DHA on prostate cancer cell LNCaP.

MAIN METHODS

Cell proliferative activity and apoptosis inducing were detected. The gene expression was detected by mRNA microarray and results were analyzed by GO and KEGG pathway database. Expressions of glycolysis key enzymes and PI3K/AKT/HIF-1α were detected by Western blot.

KEY FINDINGS

Results indicated that DHA could inhibit the LNCaP cell proliferation considerably and induce cell apoptosis. mRNA microarray showed 1293 genes were upregulated and 2322 genes were downregulated. GO and KEGG enrichment analysis suggested that glycolysis pathway was correlated with DHA inhibited the proliferation on the LNCaP cell. Western blot results showed that DHA can decrease GLUT1 and regulatory enzymes of glycolytic pathway expression probably by suppressing the activity of the intracellular Akt/mTOR and HIF-1 α.

SIGNIFICANCE

Experimental validation results indicate that DHA treatment can inhibit the LNCaP cell proliferation and induce apoptosis, which may be related to glycolysis inhibition.

The HSP90/Akt pathway may mediate artemether-induced apoptosis of Cal27 cells

Tongue squamous cell carcinoma is the most common malignant tumor in oral and maxillofacial regions. Recent research has found that artemether can inhibit growth and induce apoptosis of cancer cells, although the mechanism is not clear. The present study aimed to explore the correlation between the HSP90/Akt pathway and artemether‐induced apoptosis of Cal27 cells. A cell counting kit‐8 and flow cytometry were used to detect the proliferation and apoptosis of Cal27 cells, respectively, mRNA expression was examined by quantitative RT‐PCR, and protein expression was detected by western blotting. Our data revealed that artemether can inhibit growth and induce apoptosis of Cal27 cells. As the artemether concentration was increased, we observed downregulation of the expression of HSP90, p‐Akt and p‐mTOR in Cal27 cells, whereas the expression of Akt was not significantly changed. We also observed a time‐dependent decrease in the expression of HSP90, p‐Akt and p‐mTOR during exposure to 0.1 mg·mL⁻¹ artemether. In conclusion, the HSP90/Akt pathway may be involved in artemether‐induced apoptosis of Cal27 cells.

Cytotoxic Effects of Artemisia annua L. and Pure Artemisinin on the D-17 Canine Osteosarcoma Cell Line

Artemisia annua has been used for centuries in Traditional Chinese Medicine. Although used as an antimalarial drug, its active compound artemisinin and the semisynthetic derivatives have also been investigated for their anticancer properties, with interesting and promising results. The aims of this research were to evaluate (i) the cytotoxicity and the antiproliferative effect of pure artemisinin and a hydroalcoholic extract obtained from A. annua on the D-17 canine osteosarcoma cell line and (ii) the intracellular iron concentration and its correlation with the cytotoxic effects. Both artemisinin and hydroalcoholic extract induced a cytotoxic effect in a dose-dependent manner. Pure artemisinin caused an increase of cells in the S phase, whereas the hydroalcoholic extract induced an evident increase in the G₂/M phase. A significant decrease of iron concentration was measured in D-17 cells treated with pure artemisinin and hydroalcoholic extract compared to untreated cells. In conclusion, although preliminary, the data obtained in this study are indicative of a more potent cytotoxic activity of the hydroalcoholic extract than pure artemisinin, indicating a possible synergistic effect of the phytocomplex and a mechanism of action involving iron and possibly ferroptosis. Considering the similarities between human and canine osteosarcomas, progress in deepening knowledge and improving therapeutic protocols will probably be relevant for both species, in a model of reciprocal translational medicine.

Effects of magnetic dihydroartemisinin nano-liposome in inhibiting the proliferation of head and neck squamous cell carcinomas

BACKGROUND

Dihydroartemisinin (DHA) was one of the most potent anticancer artemisinin-like compounds that had been proved by many researchers, but its application was limited by its own characteristics.

PURPOSE

Magnetic DHA nano-liposomes (DHA-MLPs) were developed to improve the targeting antitumor efficiency and bioavailability of DHA, and their physical properties were characterized.

STUDY DESIGN AND METHODS

Liposomes were prepared by thin film dispersion and orthogonal experimental design was used to optimize the formula. The magnetic targeting and antitumor effects of DHA-MLPs in the externally applied magnetic field was investigated in vitro and in vivo.

RESULTS

The mean particle size of DHA-MLPs was 209.10 ± 4.92 nm, the charge potential was -37.13 ± 1.01 mV, the encapsulation efficiency (E.E.%) was 82.12 ± 0.91%, and the saturation magnetization at room temperature was 11.84 emu g^-1. Targeting DHA-MLPs as well as free DHA could lead to cell cycle G₁ block and apoptosis of HNSCC tumor cells in vitro. The tumor volumes of targeting DHA-MLPs treated mouse group were distinctly decreased than that in the control group, free DHA group and non-targeting DHA-MLPs group (P < 0.05). It was observed from iron staining intensity that DHA-MLPs had significant targeting effect in magnetic field (P < 0.05).

CONCLUSION

This novelty liposome could strengthen the ability of DHA in tumor suppression, by increasing the targeted delivery of DHA and biocompatibility, optimize the bioefficacy of DHA.

Dihydroartemisinin triggers c-Myc proteolysis and inhibits protein kinase B/glycogen synthase kinase 3β pathway in T-cell lymphoma cells

Recent studies have revealed a positive therapeutic effect of dihydroartemisinin (DHA) on tumor cells. However, the underlying mechanism of this has not yet been elucidated. The present study examined the potential therapeutic role and mechanism of DHA in T-cell lymphoma cells. It was revealed that DHA inhibited the proliferation of Jurkat and HuT-78 T-cell lymphoma cells in a concentration- and time-dependent manner. Furthermore, DHA reduced c-Myc protein expression at the transcriptional level, and induced the phosphorylation of c-Myc and the degradation of c-Myc oncoprotein levels. DHA treatment resulted in decreased phosphorylation of protein kinase B (Akt) and glycogen synthase 3β (GSK3β) in T-cell lymphoma cells. In addition, DHA treatment induced cell apoptosis, which was accompanied by an increased ratio of Bax/Bcl-2. Taken together, the results of the present study suggested that DHA may exert its antitumor role by accelerating c-Myc proteolysis and inhibiting the Akt/GSK3β pathway in T-cell lymphoma cells.

Dihydroartemisinin increases gemcitabine therapeutic efficacy in ovarian cancer by inducing reactive oxygen species

Ovarian cancer is the major cause of death in women gynecological malignancy and gemcitabine (GEM) is commonly used in related chemotherapy. However, more than 90% GEM is catalyzed into an inactive metabolite 2'-deoxy-2',2'-difluorouridine by stromal and cellular cytidine deaminase (CDA). Dihydroartemisinin (DHA), which possesses an intramolecular endoperoxide bridge, could be activated by heme or ferrous iron to produce reactive oxygen species (ROS). The excess ROS generation will excite expression of heme oxygenase-1 and suppress CDA expression. Under low CDA expression, the inactivation of GEM is decreased in turn to exert excellent therapeutic efficiency. Herein, we first studied the ROS generation by DHA in vitro with A2780 cells by means of flow cytometry and confocal laser scanning microscopy. Furthermore, cytotoxicity assay in vitro showed that DHA + GEM had synergistic effect, with molar ratio of DHA and GEM at 10. Eventually, in A2780 ovarian cancer xenograft tumor model, DHA + GEM exhibited significant antitumor efficiency with lower blood toxicity than GEM alone. Noteworthy, the combination treatment group completely eliminated the tumors on day 14.

Dihydroartemisinin induces apoptosis and autophagy-dependent cell death in cholangiocarcinoma through a DAPK1-BECLIN1 pathway

Cholangiocarcinoma (CCA) is a very aggressive cancer arising from the malignant transformation of cholangiocytes. Intrahepatic CCA is associated with reactive inflammation and intense fibrosis of the hepatobiliary tract. Dihydroartemisinin (DHA), the active compound found in Artemisia annua, has been shown to possess anti-tumor activity in a variety of human cancers, including hepatoma. Here, we tested the ability of DHA to specifically kill CCA cells and have investigated the underlying mechanisms. DHA induced both apoptosis and autophagy-dependent caspase-independent cell death in many CCA cell lines, while being slightly toxic to immortalized cholangiocytes. DHA induced the expression of many apoptosis- and autophagy-related genes in CCA cells. In particular, it greatly induced the expression of DAPK1, and reduced the interaction of BECLIN1 with BCL-2 while promoting its interaction with PI3KC3. Genetic silencing of DAPK1 prevented DHA-induced autophagy. Pharmacologic and genetic inhibition of BECLIN1 function prevented autophagy and cell death induced by DHA in CCA cells. These data unravel a novel pathway of DHA cancer toxicity and open the possibility to introduce DHA in the therapeutic regimen for the treatment of CCA.

Uncovering the pharmacological response of novel sesquiterpene derivatives that differentially alter gene expression and modulate the cell cycle in cancer cells

The present study aimed to assess the pharmacological anticancer profile of three natural and five synthetic sesquiterpenes developed by total chemical synthesis. To this end, their properties at the cellular and molecular level were evaluated in a panel of normal and cancer cell lines. The results obtained by performing cytotoxicity assays and gene expression analysis by reverse transcription-quantitative polymerase chain reaction showed that: i) Among the sesquiterpene derivatives analyzed, VDS58 exhibited a notable anticancer profile within attached (U-87 MG and MCF-7) and suspension (K562 and MEL-745) cancer cell cultures; however, U-87 MG cells were able to recover their proliferation capacity rapidly after 48 h of exposure; ii) gene expression profiling of U-87 MG cells, in contrast to K562 cells, showed a transient induction of cyclin-dependent kinase inhibitor 1A (CDKN1) expression; iii) the expression levels of transforming growth factor β1 (TGFB1) increased after 12 h of exposure of U-87 MG cells to VDS58 and were maintained at this level throughout the treatment period; iv) in K562 cells exposed to VDS58, TGFB1 expression levels were upregulated for 48 h and decrease afterwards; and v) the re-addition of VDS58 in U-87 MG cultures pretreated with VDS58 resulted in a notable increase in the expression of caspases (CASP3 and CASP9), BCL2‑associated agonist of cell death (BAD), cyclin D1, CDK6, CDKN1, MYC proto-oncogene bHLH transcription factor (MYC), TGFB1 and tumor suppressor protein p53. This upregulation persisted only for 24 h for the majority of genes, as afterwards, only the expression of TGFB1 and MYC was maintained at high levels. Through bioinformatic pathway analysis of RNA-Seq data of parental U-87 MG and K562 cells, substantial variation was reported in the expression profiles of the genes involved in the regulation of the cell cycle. This was associated with the differential pharmacological profiles observed in the same cells exposed to VDS58. Overall, the data presented in this study provide novel insights into the molecular mechanisms of action of sesquiterpene derivatives by dysregulating the expression levels of genes associated with the cell cycle of cancer cells.

Opening of the CLC-3 chloride channel induced by dihydroartemisinin contributed to early apoptotic events in human poorly differentiated nasopharyngeal carcinoma cells

Nasopharyngeal carcinoma (NPC) is a specific type of head and neck cancer that is prevalent in Southeast Asia. Dihydroartemisinin (DHA), a semisynthetic derivative of artemisinin, has specific anticancer activity. Here, we aimed to investigate the role of the CLC-3 chloride channel in the anticancer effect of DHA in poorly differentiated NPC CNE-2Z cells. First, we observed that DHA could specifically inhibit the proliferation, induce apoptosis, and increase cleaved caspase-3 expression in the CNE-2Z cells. Then, we found that DHA could activate chloride channels, which led to Cl^- efflux and apoptotic volume decrease (AVD) in the early stage in the CNE-2Z cells. DHA also specifically increased CLC-3 chloride channel protein expression in the CNE-2Z cells. Silencing of the CLC-3 protein expression depleted the Cl^- currents, and decreased the AVD capacity and cell apoptosis induced by DHA. Finally, we revealed that the [Ca²⁺ ]_i increased after around 6 hours of treatment with DHA, which was also inhibited by silencing of the CLC-3 protein expression. Our data demonstrated that the selective antitumor activities of DHA in NPC may occur through the specific activation of the CLC-3 Cl^- channel, leading to Cl^- efflux, and induced AVD, then led to [Ca²⁺ ]_i accumulation and caspase-3 activation, and finally induced apoptosis. The activation of the CLC-3 chloride channel played an essential and proximal upstream role in the antitumor activities of DHA.

Anticancer Effects of Dihydroartemisinin on Human Esophageal Cancer Cells In Vivo

Despite recent advances in chemotherapy and surgical resection, the 5-year survival rate of esophageal cancer still remains at the low level. Therefore, it is very important to discover a new agent to improve the life expectancy of patients with esophageal cancer. Dihydroartemisinin (DHA), a semisynthetic derivative of artemisinin, has recently exhibited promising anticancer activity against various cancer cells. But so far, the specific mechanism remains unclear. We have previously demonstrated that DHA reduced viability of esophageal cancer cells in a dose-dependent manner in vitro and induced cell cycle arrest and apoptosis. Here, we extended our study to further observe the efficacy of DHA on esophageal cancer cells in vivo. In the present study, for the first time, we found that DHA significantly inhibits cell proliferation in xenografted tumor compared with the control. The mechanism was that DHA induced cell apoptosis in both human esophageal cancer cell lines Eca109 and Ec9706 in vivo in a dose-dependent manner. The results suggested that DHA was a promising agent against esophageal cancer in the clinical treatment.

Dihydroartemisinin potentiates antitumor activity of 5-fluorouracil against a resistant colorectal cancer cell line

Although the combination of chemotherapy and surgical resection has effectively increased the survival rate of colorectal cancer patients in recent decades, acquired drug resistance is still a problem that leads to treatment failure. Dihydroartemisinin (DHA), a semisynthetic derivative of artemisinin, has recently been reported to show anticancer effects against numerous types of cancer, including colorectal cancer. This study showed that DHA exerted a strong anticancer effect against several colorectal cancer cell lines. We also found that p53 knockout colorectal cancer HCT116 cells (HCT116 TP53^-/-) were not sensitive to 5-fluorouracil (5-FU) treatment, unlike wild-type HCT116 cells. Interestingly, co-treatment with DHA could effectively restore the anticancer effect of 5-FU against HCT116 TP53^-/- cells, which manifested as the inhibition of proliferation and induction of reactive oxygen species (ROS)-mediated apoptosis and was accompanied by the upregulation of B-cell lymphoma 2 (BCL-2) and downregulation of the BCL-2-associated X protein (BAX). These findings suggested that DHA could effectively sensitize cells to 5-FU through ROS-mediated apoptosis and the alteration of the BCL-2/BAX expression ratio, which indicated that this may be one of the mechanisms of the DHA-promoted 5-FU anticancer effect.

Dihydroartemisinin induced caspase-dependent apoptosis through inhibiting the specificity protein 1 pathway in hepatocellular carcinoma SK-Hep-1 cells

AIMS

Dihydroartemisinin (DHA) is a semi-synthetic derivative of artemisinin, well known for a safe and effective first-line antimalarial agent. This study investigated whether and how DHA induces apoptosis focusing on the specificity protein 1 (Sp1) pathway in hepatocellular carcinoma (HCC) SK-Hep-1 cells.

MAIN METHODS

The cell viability was evaluated by MTT assay. Cell cycle analysis was performed after PI staining by flow cytometry system. Apoptosis was confirmed by DAPI staining and by detecting cytoplasmic histone-associated-DNA-fragments using a cell death detection ELISAPLUS kit. The expression of proteins involved in apoptosis was evaluated by Western blot. The nuclear localization of Sp1 was evaluated by immunofluorescence assay.

KEY FINDINGS

DHA exerted potent cytotoxicity against HCC SK-Hep-1 cells compared with normal hepatocyte AML12 cells. The sub-G1 DNA content and apoptosis index were increased by DHA, which was accompanied by nuclei condensation and fragmentation. DHA activated caspase 3, caspase 8, and caspase 9 and cleaved poly (ADP-ribose) polymerase (PARP). DHA-induced apoptotic cell death, activation of caspases and cleavage of PARP were dramatically inhibited by pan caspase inhibitor Z-VAD-FMK. DHA down-regulated protein expression and nuclear localization of Sp1, which in turn decreased Sp1 downstream target protein, X-linked inhibitor of apoptosis. Decreased Sp1 protein expression by DHA was restored by proteasome inhibitor MG132. DHA led to a down-regulation of phospho-ERK, -p38 and -JNK without affecting their total forms.

SIGNIFICANCE

These results demonstrate that DHA induces caspase-dependent apoptosis in HCC SK-Hep-1 cells by proteasome-dependent degradation of Sp1, which is involved in mitogen-activate protein kinase pathway.

Cyclic AMP efflux inhibitors as potential therapeutic agents for leukemia

Apoptotic evasion is a hallmark of cancer. We propose that some cancers may evade cell death by regulating 3′-5′-cyclic adenosine monophosphate (cAMP), which is associated with pro-apoptotic signaling. We hypothesize that leukemic cells possess mechanisms that efflux cAMP from the cytoplasm, thus protecting them from apoptosis. Accordingly, cAMP efflux inhibition should result in: cAMP accumulation, activation of cAMP-dependent downstream signaling, viability loss, and apoptosis. We developed a novel assay to assess cAMP efflux and performed screens to identify inhibitors. In an acute myeloid leukemia (AML) model, several identified compounds reduced cAMP efflux, appropriately modulated pathways that are responsive to cAMP elevation (cAMP-responsive element-binding protein phosphorylation, and deactivation of Very Late Antigen-4 integrin), and induced mitochondrial depolarization and caspase activation. Blocking adenylyl cyclase activity was sufficient to reduce effects of the most potent compounds. These compounds also decreased cAMP efflux and viability of B-lineage acute lymphoblastic leukemia (B-ALL) cell lines and primary patient samples, but not of normal primary peripheral blood mononuclear cells. Our data suggest that cAMP efflux is a functional feature that could be therapeutically targeted in leukemia. Furthermore, because some of the identified drugs are currently used for treating other illnesses, this work creates an opportunity for repurposing.

Dihydroartemisinin-induced apoptosis in human acute monocytic leukemia cells

Dihydroartemisinin (DHA) is a derivative of artemisinin. The present study aimed to investigate whether DHA induces apoptosis in the THP-1 human acute monocytic leukemia cell line (AMoL), and to identify the relative molecular mechanisms. The results of the present study demonstrated that the viability of THP-1 cells were inhibited by DHA in a dose- and time-dependent manner, which was accompanied by morphological characteristics associated with apoptosis. After 24 h of 200 µM DHA treatment, the proportion of apoptotic cells was significantly increased compared with the untreated controls (P<0.01). In addition, DHA downregulated the levels of B-cell lymphoma (Bcl)-2, protein kinase B (Akt)1, Akt2 and Akt3 gene expression, and increased the expression of the Bcl-2-associated X protein apoptosis regulator. The protein expression of phospho-Akt and phospho-extracellular signal-regulated kinase (ERK) was also decreased, and the protein expression level of cleaved caspase-3 was increased following treatment with DHA. Therefore, DHA may induce apoptosis in the AMoL THP-1 cell line via currently unknown underlying molecular mechanisms, including the downregulation of ERK and Akt, and the activation of caspase-3.