Halofuginone and artemisinin synergistically arrest cancer cells at the G1/G0 phase by upregulating p21Cip1 and p27Kip1

New uses of halofuginone to treat cancer

The small-molecule alkaloid halofuginone (HF) is obtained from febrifugine. Recent studies on HF have aroused widespread attention owing to its universal range of noteworthy biological activities and therapeutic functions, which range from parasite infections and fibrosis to autoimmune diseases. In particular, HF is believed to play an excellent anticancer role by suppressing the proliferation, adhesion, metastasis, and invasion of cancers. This review supports the goal of demonstrating various anticancer effects and molecular mechanisms of HF. In the studies covered in this review, the anticancer molecular mechanisms of HF mainly included transforming growth factor-β (TGF-β)/Smad-3/nuclear factor erythroid 2-related factor 2 (Nrf2), serine/threonine kinase proteins (Akt)/mechanistic target of rapamycin complex 1(mTORC1)/wingless/integrated (Wnt)/β-catenin, the exosomal microRNA-31 (miR-31)/histone deacetylase 2 (HDAC2) signaling pathway, and the interaction of the extracellular matrix (ECM) and immune cells. Notably, HF, as a novel type of adenosine triphosphate (ATP)-dependent inhibitor that is often combined with prolyl transfer RNA synthetase (ProRS) and amino acid starvation therapy (AAS) to suppress the formation of ribosome, further exerts a significant effect on the tumor microenvironment (TME). Additionally, the combination of HF with other drugs or therapies obtained universal attention. Our results showed that HF has significant potential for clinical cancer treatment.

Experimental study on the inhibitory effect of Halofuginone on NSCLC

In recent decades, significant advancements have been achieved in non-small cell lung cancer (NSCLC) treatment. However, drug resistance, postoperative recurrence, distant metastasis, and other critical issues arise during NSCLC treatment. Natural products play a crucial role in the development of anti-tumor drugs. Halofuginone (HF) is a derivative of Febrifugine, an extract of Dichroa febrifuga Lour, a traditional Chinese medicine. Recent studies on HF have demonstrated its antitumor activity and great potential for clinical applications. However, its antitumor effects and mechanisms in NSCLC remain unknown. This study aimed to elucidate the antitumor effect of HF on NSCLC and preliminarily explore its mechanism of action. The proliferation-related assay revealed that HF could inhibit the proliferation of lung adenocarcinoma cells HCC827 and H1975. Network pharmacology of HF and NSCLC indicated that HF could induce cellular oxidative stress, and the antitumor effect was related to autophagy, apoptosis, and cell cycle arrest. Experimental analysis using flow cytometry and western blotting confirmed that HF indeed induced autophagy, enhanced apoptosis, and caused cell cycle arrest. The addition of N-acetyl-cysteamine acid inhibits the HF-induced increase in reactive oxygen species levels, inhibits autophagy and apoptosis, and alters cell cycle distribution. The HCC827 transplantation tumor animal model established that HF substantially inhibited the growth of transplanted tumors. These findings suggest that HF exerts a significant inhibitory effect on NSCLC in vivo and in vitro. The inhibitory effect of HF on NSCLC was associated with the increase of ROS in tumor cells, induction of autophagy and apoptosis, and cell cycle arrest.

Targeting Ferroptosis: Small-molecule Inducers as Novel Anticancer Agents

Ferroptosis, a distinct form of regulated cell death characterized by iron-dependent lipid peroxidation and reactive oxygen species (ROS) accumulation, is increasingly recognized for its role in cancer development and as a potential therapeutic target. This review consolidates insights into the molecular mechanisms underpinning ferroptosis and evaluates the therapeutic potential of small-molecule inducers, such as erastin, RSL3, sulfasalazine, and sorafenib, which selectively trigger ferroptosis in cancer cells. It highlights the distinct morphological and molecular signatures of ferroptosis, its complex interplay with iron, lipid, and amino acid metabolic pathways, and the resultant implications for cancer treatment strategies. Strategic manipulation of the ferroptosis pathway offers a groundbreaking approach to cancer treatment, potentially circumventing the resistance that cancers develop against traditional apoptosis-inducing agents. Furthermore, it also emphasizes the necessity of refining these small molecules for clinical application and exploring their synergistic potential when combined with current therapies to augment overall treatment efficacy and improve patient outcomes. Ferroptosis thus emerges as a promising avenue in the realm of cancer therapy. Moving forward, research endeavors should focus on a more nuanced understanding of the interconnections between ferroptosis and other cell death modalities. Additionally, comprehensive evaluations of the long-term safety and therapeutic indices of the involved compounds are imperative. Such investigations are poised to herald a transformative shift in the paradigm of oncology, paving the way for innovative and targeted interventions.

Evaluation of Anticancer Efficacy of D-α-Tocopheryl Polyethylene-Glycol Succinate and Soluplus® Mixed Micelles Loaded with Olaparib and Rapamycin Against Ovarian Cancer

Purpose

Ovarian cancer has the highest mortality rate and lowest survival rate among female reproductive system malignancies. There are treatment options of surgery and chemotherapy, but both are limited. In this study, we developed and evaluated micelles composed of D-α-tocopheryl polyethylene-glycol (PEG) 1000 succinate (TPGS) and Soluplus® (SOL) loaded with olaparib (OLA), a poly(ADP-ribose)polymerase (PARP) inhibitor, and rapamycin (RAPA), a mammalian target of rapamycin (mTOR) inhibitor in ovarian cancer.

Methods

We prepared micelles containing different molar ratios of OLA and RAPA embedded in different weight ratios of TPGS and SOL (OLA/RAPA-TPGS/SOL) were prepared and physicochemical characterized. Furthermore, we performed in vitro cytotoxicity experiments of OLA, RAPA, and OLA/RAPA-TPGS/SOL. In vivo toxicity and antitumor efficacy assays were also performed to assess the efficacy of the mixed micellar system.

Results

OLA/RAPA-TPGS/SOL containing a 4:1 TPGS:SOL weight ratio and a 2:3 OLA:RAPA molar ratio showed synergistic effects and were optimized. The drug encapsulation efficiency of this formulation was >65%, and the physicochemical properties were sustained for 180 days. Moreover, the formulation had a high cell uptake rate and significantly inhibited cell migration (**p < 0.01). In the in vivo toxicity test, no toxicity was observed, with the exception of the high dose group. Furthermore, OLA/RAPA-TPGS/SOL markedly inhibited tumor spheroid and tumor growth in vivo.

Conclusion

Compared to the control, OLA/RAPA-TPGS/SOL showed significant tumor inhibition. These findings lay a foundation for the use of TPGS/SOL mixed micelles loaded with OLA and RAPA in the treatment of ovarian cancer.

In Vitro and In Vivo Anti-Cancer Activity of Lasiokaurin in a Triple-Negative Breast Cancer Model

Due to its intricate heterogeneity, high invasiveness, and poor prognosis, triple-negative breast cancer (TNBC) stands out as the most formidable subtype of breast cancer. At present, chemotherapy remains the prevailing treatment modality for TNBC, primarily due to its lack of estrogen receptors (ERs), progesterone receptors (PRs), and human epidermal growth receptor 2 (HER2). However, clinical chemotherapy for TNBC is marked by its limited efficacy and a pronounced incidence of adverse effects. Consequently, there is a pressing need for novel drugs to treat TNBC. Given the rich repository of diverse natural compounds in traditional Chinese medicine, identifying potential anti-TNBC agents is a viable strategy. This study investigated lasiokaurin (LAS), a natural diterpenoid abundantly present in Isodon plants, revealing its significant anti-TNBC activity both in vitro and in vivo. Notably, LAS treatment induced cell cycle arrest, apoptosis, and DNA damage in TNBC cells, while concurrently inhibiting cell metastasis. In addition, LAS effectively inhibited the activation of the phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway and signal transducer and activator of transcription 3 (STAT3), thus establishing its potential for multitarget therapy against TNBC. Furthermore, LAS demonstrated its ability to reduce tumor growth in a xenograft mouse model without exerting detrimental effects on the body weight or vital organs, confirming its safe applicability for TNBC treatment. Overall, this study shows that LAS is a potent candidate for treating TNBC.

Medicinal and mechanistic overview of artemisinin in the treatment of human diseases

Artemisinin (ART) is a bioactive compound isolated from the plant Artemisia annua and has been traditionally used to treat conditions such as malaria, cancer, viral infections, bacterial infections, and some cardiovascular diseases, especially in Asia, North America, Europe and other parts of the world. This comprehensive review aims to update the biomedical potential of ART and its derivatives for treating human diseases highlighting its pharmacokinetic and pharmacological properties based on the results of experimental pharmacological studies in vitro and in vivo. Cellular and molecular mechanisms of action, tested doses and toxic effects of artemisinin were also described. The analysis of data based on an up-to-date literature search showed that ART and its derivatives display anticancer effects along with a wide range of pharmacological activities such as antibacterial, antiviral, antimalarial, antioxidant and cardioprotective effects. These compounds have great potential for discovering new drugs used as adjunctive therapies in cancer and various other diseases. Detailed translational and experimental studies are however needed to fully understand the pharmacological effects of these compounds.

The anti-inflammatory activity of the compounds isolated from Dichroa febrifuga leaves

Dichroa febrifuga Lour. is a traditional medicinal herb that has been applied in the treatment of malaria and some other infectious diseases. Studies recently have focused on the anti-inflammation of the extracts of Dichroa febrifuga Lour. although there have not many reports about which compounds play the essential role. Therefore, in this study, we isolated hydrangenoside C (1), isoarborinol (2), and methyl 1,3,4,6-tetra-O-acetyl-fructofuranoside (3) from the leaves of Dichroa febrifuga. Subsequently, the anti-inflammatory property of 1-3 was assessed using an in vivo assay of edema mouse model which was induced by carrageenan. Out of the three, 2 inhibited the edema effectively and dose-dependently, similarly to diclofenac while there was no obvious activity observed in 1 and 3. The in silico results demonstrated that 2 enables binding to 5-LOX and PLA2 via generating h-bonds. This is the first study to mention the anti-inflammation of 2 in Dichroa febrifuga Lour., and would be a contribution to further studies to elucidate the promising bioactivities of this compound.

A comprehensive overview of Artemisinin and its derivatives as anticancer agents

Artemisinin is the crucial ingredient of artemisia annua, a traditional Chinese medicine used for the therapy of malaria in China for hundreds of years. In recent years, the anticancer properties of artemisinin and its derivatives have also been reported. This review has summarized the research and development of artemisinin and its derivatives as anticancer agents, which included both natural and synthetic monomers as well as their dimers. In addition, it highlights the antitumor effects of artemisinin and its derivatives after site-modification or after transformation to a nano-delivery system. Moreover, we have further explored their potential mechanisms of action and also discussed the clinical trials of ARTs used to treat cancer, which will facilitate in further development of novel anticancer drugs based on the scaffold of artemisinin.

Drug Repurposing Strategies for Non-Cancer to Cancer Therapeutics

Global efforts invested for the prevention and treatment of cancer need to be repositioned to develop safe, effective, and economic anticancer therapeutics by adopting rational approaches of drug discovery. Drug repurposing is one of the established approaches to reposition old, clinically approved off patent noncancer drugs with known targets into newer indications. The literature review suggests key role of drug repurposing in the development of drugs intended for cancer as well as noncancer therapeutics. A wide category of noncancer drugs namely, drugs acting on CNS, anthelmintics, cardiovascular drugs, antimalarial drugs, anti-inflammatory drugs have come out with interesting outcomes during preclinical and clinical phases. In the present article a comprehensive overview of the current scenario of drug repurposing for the treatment of cancer has been focused. The details of some successful studies along with examples have been included followed by associated challenges.

Cell death mechanisms induced by synergistic effects of halofuginone and artemisinin in colorectal cancer cells

Our previous study found that the combination of halofuginone (HF) and artemisinin (ATS) synergistically arrest colorectal cancer (CRC) cells at the G1/G0 phase of the cell cycle; however, it remains unclear whether HF-ATS induces cell death. Here we report that HF-ATS synergistically induced caspase-dependent apoptosis in CRC cells. Specifically, both in vitro and in vivo experiments showed that HF or HF-ATS induces apoptosis via activation of caspase-9 and caspase-8 while only caspase-9 is involved in ATS-induced apoptosis. Furthermore, we found HF or HF-ATS induces autophagy; ATS can't induce autophagy until caspase-9 is blocked. Further analyzing the crosstalk between autophagic and caspase activation in CRC cells, we found autophagy is essential for activation of caspase-8, and ATS switches to activate capase-8 via induction of autophagy when caspase-9 is inhibited. When apoptosis is totally blocked, HF-ATS switches to induce autophagic cell death. This scenario was then confirmed in studies of chemoresistance CRC cells with defective apoptosis. Our results indicate that HF-ATS induces cell death via interaction between apoptosis and autophagy in CRC cells. These results highlight the value of continued investigation into the potential use of this combination in cancer therapy.

Exploring the mechanisms of anti-ovarian cancer of Hedyotis diffusa Willd and Scutellaria barbata D. Don through focal adhesion pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Hedyotis diffusa Willd and Scutellaria barbata D.Don (HD-SB) pairing were widely used as traditional medicine known for their anti-tumor effects. However, the inhibitory effect of HD-SB on ovarian cancer and its potential mechanisms were still not clear.

AIM OF THE STUDY

Our study identified the anti-tumor effect of HD-SB on ovarian cancer and analyzed the potential mechanisms by the network pharmacology and molecular docking method.

MATERIALS AND METHODS

The inhibitory effect of HD-SB combination on the growth and migration of ovarian cancer was detected by MTT and transwell assays. The effective ingredients of HD-SB and their potential targets were obtained from the Traditional Chinese Medicines for Systems Pharmacology Database (TCMSP), the GeneCards database, and the UniProt database. The relationships between active ingredients of HD-SB and potential targets or pathways of ovarian cancer were analyzed by String database, Cytoscape 3.7.2 software, and David 6.7 online database. The anti-ovarian cancer targets of HD-SB in the focal adhesion pathway were identified by RT-qPCR and molecular docking.

RESULTS

HD-SB combination significantly inhibited the proliferation and migration of ovarian cancer cells. We observed that the 1:2 ratio of HD-SB had the lowest IC50 value. 60 gene targets of 33 active ingredients in HD-SB were selected by pharmacokinetic parameters. The network pharmacological analysis showed that quercetin, luteolin, and baicalein might be the important anti-ovarian cancer ingredients in HD-SB, and the inhibitory effects of these three ingredients on the proliferation of ovarian cancer cells were verified respectively. Functional enrichment results suggested that HD-SB inhibited ovarian cancer growth and migration mainly through the focal adhesion pathway and the potential targets were EGFR, MAPK1, VEGFA, and PIK3CG.

CONCLUSIONS

HD-SB pairing significantly inhibited the proliferation and migration of ovarian cancer. Using network pharmacological methods and validation experiments, we found that HD-SB might, at least partially, inhibit ovarian cancer through the focal adhesion pathway. We believed that the HD-SB combination could be a potential therapeutic drug for the treatment of ovarian cancer patients.

Halofuginone functions as a therapeutic drug for chronic periodontitis in a mouse model

Periodontitis is an inflammatory disease caused by host immune response, resulting in a loss of periodontium and alveolar bone. Immune cells, such as T cells and macrophages, play a critical role in the periodontitis onset. Halofuginone, a natural quinazolinone alkaloid, has been shown to possess anti-fibrosis, anti-cancer, and immunomodulatory properties. However, the effect of halofuginone on periodontitis has never been reported. In this study, a ligature-induced mice model of periodontitis was applied to investigate the potential beneficial effect of halofuginone on periodontitis. We demonstrated that the administration of halofuginone significantly reduced the expression levels of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) in vivo, and markedly suppressed immune cell infiltration into the infected sites. Furthermore, we also observed that halofuginone treatment blocked the T-helper 17 (Th17) cell differentiation in vivo and in vitro. We demonstrated for the first time that halofuginone alleviated the onset of periodontitis through reducing immune responses.

1,2,3-Triazole tethered 1,2,4‑trioxane trimer induces apoptosis in metastatic cancer cells and inhibits their proliferation, migration and invasion

Artemisinin (ART) has been in use against different cancer cells and its derivatives and conjugates are more cytotoxic to iron-rich cancer cells. It is desirable to develop easily achievable synthetic 1,2,4-trioxanes having the same pharmacophore as that of ART. To explore more efficient compounds, a 1,2,3-triazole tethered 1,2,4‑trioxane trimer (4T) was synthesized and the anti-cancer effects of ART and 4T on MDA-MB-435 and MDA-MB-231 cells were investigated concerning regulation of osteopontin (OPN) expression, which is associated with cancer progression and malignancy. ¹H NMR and ¹³C NMR, oxidative stress analysis, flow cytometry, western blot, Real-Time PCR, transfections, luciferase assay, cell viability, proliferation, migration and chemotactic invasion assays were used in this study. It was observed that the 4T induced apoptosis by inhibiting Bcl-2 (~0.6-fold) and cleavage of caspase-3 (intrinsic pathway) in these metastatic cancer cells, and also reduced colony formation, migration and invasion of these cancer cells. The treatment of 4T decreased the reduced glutathione level and increased the activities of glucose-6-phosphate dehydrogenase and glutathione reductase in the 4T treated cancer cells as compared to their respective controls. Further, the expression of OPN was diminished (~0.5-fold) by the 4T in these cell lines. It was also observed that the key mitogen-activated protein kinase pathway proteins, mitogen-activated protein kinase kinase1/2 (~1.8-fold) and extracellular signal-regulated kinase1/2 (~16-fold), were also activated following the treatment of the 4T. However, the phosphorylated c-Jun level, a component of activator protein-1, was significantly reduced in these cancer cells upon 4T treatment. Taken together, we hypothesize that 4T may be useful for controlling cancer progression and malignancy.

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.

Anticarcinogenic effects of halofuginone on lung-derived cancer cells

Malignant mesothelioma is a rare but aggressive form of malignancy, which is difficult to diagnose and is resistant to current chemotherapeutic treatment options. Molecular techniques have been used to investigate the mechanisms of action and the beneficial therapeutic effects of halofuginone (HF) in several cancers but not malignant mesotheliomas. In this study, the antiproliferative and apoptotic effects of HF were investigated through its ability to deregulate EGFR downstream signalling cascade proteins in the pathologically aggressive malignant mesothelioma and non-small-cell lung cancer cells. We showed that administration of HF at nanomolar concentrations induced a dose-dependent reduction in the viability of cancer cells, made cell cycle arrest, inhibited proliferation of cancer cells via STAT3 and ERK1/2 pathways and triggered the apoptotic cascade via p38MAPK. We demonstrated that the apoptotic cell death mechanism was mediated by enhanced activation of caspase-3 and concomitant PARP cleavage, downregulation of Bcl-2 and upregulation of Bax in both malignant mesothelioma and lung cancer cells. In particular, we demonstrated that cancer cells were more sensitive to HF treatment than normal mesothelial cells. Taken together, this study suggests that HF exerts its anticancer effects in lung-derived cancers by targeting signal transduction pathways mainly through deregulation of ERK1/2, STAT3 and p38MAPK to reduce cancer cell viability, induce cell cycle arrest and apoptotic cell death. Thus, HF might be considered as a potential agent against malignant mesothelioma and/or lung cancer cells.

Artemisinin compounds sensitize cancer cells to ferroptosis by regulating iron homeostasis

The antimalarial drug artemisinin and its derivatives have been explored as potential anticancer agents, but their underlying mechanisms are controversial. In this study, we found that artemisinin compounds can sensitize cancer cells to ferroptosis, a new form of programmed cell death driven by iron-dependent lipid peroxidation. Mechanistically, dihydroartemisinin (DAT) can induce lysosomal degradation of ferritin in an autophagy-independent manner, increasing the cellular free iron level and causing cells to become more sensitive to ferroptosis. Further, by associating with cellular free iron and thus stimulating the binding of iron-regulatory proteins (IRPs) with mRNA molecules containing iron-responsive element (IRE) sequences, DAT impinges on IRP/IRE-controlled iron homeostasis to further increase cellular free iron. Importantly, in both in vitro and a mouse xenograft model in which ferroptosis was triggered in cancer cells by the inducible knockout of GPX4, we found that DAT can augment GPX4 inhibition-induced ferroptosis in a cohort of cancer cells that are otherwise highly resistant to ferroptosis. Collectively, artemisinin compounds can sensitize cells to ferroptosis by regulating cellular iron homeostasis. Our findings can be exploited clinically to enhance the effect of future ferroptosis-inducing cancer therapies.

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.

Effects of Jaeumkanghwa-tang on tamoxifen responsiveness in preclinical ER+ breast cancer model

Resistance to endocrine therapy remains a clinical challenge in the treatment of estrogen receptor-positive (ER+) breast cancer. We investigated if adding a traditional Asian herbal mixture consisting of 12 herbs, called Jaeumkanghwa-tang (JEKHT), to tamoxifen (TAM) therapy might prevent resistance and recurrence in the ER+ breast cancer model of 7,12-dimethylbenz[a]anthracene (DMBA)-exposed Sprague-Dawley rats. Rats were divided into four groups treated as follows: 15 mg/kg TAM administered via diet as TAM citrate (TAM only); 500 mg/kg JEKHT administered via drinking water (JEKHT only group); TAM + JEKHT and no treatment control group. The study was replicated using two different batches of JEKHT. In both studies, a significantly higher proportion of ER+ mammary tumors responded to TAM if animals also were treated with JEKHT (experiment 1: 47% vs 65%, P = 0.015; experiment 2: 43% vs 77%, P < 0.001). The risk of local recurrence also was reduced (31% vs 12%, P = 0.002). JEKHT alone was mostly ineffective. In addition, JEKHT prevented the development of premalignant endometrial lesions in TAM-treated rats (20% in TAM only vs 0% in TAM + JEKHT). Co-treatment of antiestrogen-resistant LCC9 human breast cancer cells with 1.6 mg/mL JEKHT reversed their TAM resistance in dose-response studies in vitro. Several traditional herbal medicine preparations can exhibit anti-inflammatory properties and may increase anti-tumor immune activities in the tumor microenvironment. In the tumors of rats treated with both JEKHT and TAM, expression of Il-6 (P = 0.03), Foxp3/T regulatory cell (Treg) marker (P = 0.033) and Tgfβ1 that activates Tregs (P < 0.001) were significantly downregulated compared with TAM only group. These findings indicate that JEKHT may prevent TAM-induced evasion of tumor immune responses.

Artemisinin derivatives inhibit epithelial ovarian cancer cells via autophagy-mediated cell cycle arrest

Epithelial ovarian cancer (EOC) is the most fatal gynecologic malignancy due to its late diagnosis and lack of curative therapy. The antimalaria compound artemisinin and its derivatives, such as artesunate (ART) and dihydroartemisinin (DHA), have proven to be potent anticancer drugs and act through various anticancer mechanisms. To identify novel targets of artemisinin derivatives in EOC cells, we investigated the effects of ART and DHA on SKOV3 and primary EOC cell growth via CCK-8 assay. Both ART and DHA inhibited EOC cell growth. A cell cycle distribution analysis showed that ART and DHA caused G2/M cell cycle arrest. Moreover, ART and DHA induced autophagy in EOC cells, whereas autophagy inhibitors reversed the cell growth inhibition and cell cycle arrest induced by ART and DHA. Western blot analysis showed that ART and DHA also suppressed the cell cycle-related NF-κB-signaling pathway in EOC cells. These data suggest that artemisinin derivatives induce autophagy, block the cell cycle, and inhibit cell growth in EOC cells. Our research provides new targets for artemisinin derivatives for EOC treatment.

Delivery of a TNF-α-derived peptide by nanoparticles enhances its antitumor activity by inducing cell-cycle arrest and caspase-dependent apoptosis

Prostate cancer is the second-most common malignancy of the male genitourinary system. TNF-α has attracted intense attention as a potential therapeutic agent against various cancers. However, its therapeutic application is restricted by short half life and severe toxic side-effects. In this study, we constructed a stable nanodrug, called TNF-α-derived polypeptide (P16)-conjugated, chitosan (CTS)-modified selenium nanoparticle (SC; SCP), which is composed of SC as a slow-release carrier conjugated to P16. SCP had significant inhibitory effects on multiple types of tumor cells, especially DU145 prostate cancer cells, but not on RWPE-1 normal human prostate epithelial cells. SCP could induce G0/G1 cell-cycle arrest and apoptosis in DU145 cells more effectively than could P16 and TNF-α. In DU145 xenograft tumor models, SCP exerted much stronger antitumor effects than P16 or estramustine (the clinical drug for prostate cancer) but caused fewer toxic side-effects. In addition, SCP significantly inhibited proliferation and accelerated apoptosis in DU145 xenograft tumors. Further mechanistic studies revealed that SCP exerted antitumor effects via activation of the p38 MAPK/JNK pathway, thus inducing G0/G1 cell-cycle arrest and caspase-dependent apoptosis. These findings suggest that SCP may represent a potential long-lasting therapeutic agent for human prostate cancer with fewer side effects.-Yan, Q., Chen, X., Gong, H., Qiu, P., Xiao, X., Dang, S., Hong, A., Ma, Y. Delivery of a TNF-α-derived peptide by nanoparticles enhances its antitumor activity by inducing cell-cycle arrest and caspase-dependent apoptosis.

Antitumor Research on Artemisinin and Its Bioactive Derivatives

Cancer is the leading cause of human death which seriously threatens human life. The antimalarial drug artemisinin and its derivatives have been discovered with considerable anticancer properties. Simultaneously, a variety of target-selective artemisinin-related compounds with high efficiency have been discovered. Many researches indicated that artemisinin-related compounds have cytotoxic effects against a variety of cancer cells through pleiotropic effects, including inhibiting the proliferation of tumor cells, promoting apoptosis, inducing cell cycle arrest, disrupting cancer invasion and metastasis, preventing angiogenesis, mediating the tumor-related signaling pathways, and regulating tumor microenvironment. More importantly, artemisinins demonstrated minor side effects to normal cells and manifested the ability to overcome multidrug-resistance which is widely observed in cancer patients. Therefore, we concentrated on the new advances and development of artemisinin and its derivatives as potential antitumor agents in recent 5 years. It is our hope that this review could be helpful for further exploration of novel artemisinin-related antitumor agents.

Hydrangenol inhibits the proliferation, migration, and invasion of EJ bladder cancer cells via p21WAF1-mediated G1-phase cell cycle arrest, p38 MAPK activation, and reduction in Sp-1-induced MMP-9 expression

Hydrangenol is a dihydroisocoumarin that is mainly obtained from Hydrangea macrophylla. Recently, hydrangenol has garnered attention since several studies have reported that it has anti-inflammatory, anti-allergic, anti-diabetic, and anti-malarial activities. However, there have been few studies on the effect of hydrangenol on oncogenesis. In this study, we evaluated the anti-cancer activity of hydrangenol against the EJ bladder cancer cell line. Hydrangenol significantly inhibited the proliferation of EJ cells in a dose-dependent manner with an IC₅₀ of 100 µM. Flow cytometry and immunoblotting experiments indicated that EJ cells were arrested in the G1-phase of the cell cycle and showed reduced expression of CDK2, CDK4, cyclin D1, and cyclin E mediated via the upregulation of p21^WAF1. Hydrangenol increased the phosphorylation of p38 MAPK without affecting the phosphorylation of ERK and JNK. In addition, hydrangenol significantly inhibited the migratory and invasive activities of EJ cells by suppressing the enzymatic activity of MMP-9. Electrophoretic mobility shift assays suggested that the inhibition of MMP-9 activity by hydrangenol was attributable to its suppression of the Sp-1 transcription factor binding activity. This study is the first report on the mode of action of hydrangenol as an inhibitor of bladder cancer. We believe that these results provide novel insights that could aid the development of hydrangenol-based chemotherapeutic agents.

Effect of artemisinin on proliferation and apoptosis-related protein expression in vivo and in vitro

Artemisinin is the first-line drugs for the treatment of malaria. In recent years, a large number of reports showed that artemisinin exhibit anti-tumor activity. In this study, we used C6 glioma cells and rat C6 brain-glioma model to study anti-tumor activity of artemisinin in vivo and in vitro. We found that artemisinin inhibited the proliferation in C6 cells and induced cell cycle arrest and a caspase-3-dependent cell apoptosis. It also inhibited the growth of C6 brain-glioma in vivo and enhanced living state of rat brain-glioma model. These results suggested that artemisinin had significant anti-tumor activities on C6 cells both in vitro and in vivo. Artemisinin might be exploited as a promising clinical anti-cancer drug in future.

Halofuginone-induced autophagy suppresses the migration and invasion of MCF-7 cells via regulation of STMN1 and p53

Traditional Chinese medicines have been recognized as especially promising anticancer agents in modern anticancer research. Halofuginone (HF), an analog of quinazolinone alkaloid extracted from Dichroa febrifuga, is widely used in traditional medicine. However, whether HF inhibits the growth of breast cancer cells and/or reduces the migration and invasion of MCF-7 human breast cancer cells, as well as the underlying mechanisms in vitro, remains unclear. In this study, we report that an HF extract inhibits the growth of MCF-7 cells and reduces their migration and invasion, an important feature of potential anticancer agents. In addition, HF significantly increases the activation of autophagy, which is closely associated with tumor metastasis. As STMN1 and p53 have been closely implicated in breast cancer progression, we analyzed their expression in the context of HF extract treatment. Western blot analysis showed that HF suppresses STMN1 and p53 expression and activity in an autophagy-dependent manner. Collectively, these data indicate that activation of autophagy reduces expression of STMN1 and p53, and the migration and invasion of cancer cells contributes to the anti-cancer effects of the HF. These findings may provide new insight into breast cancer prevention and therapy.

Transcriptome analysis of genes associated with breast cancer cell motility in response to Artemisinin treatment

Background

Well-known anti-malarial drug artemisinin exhibits potent anti-cancerous activities. In-vivo and in-vitro studies showed its anti-tumor and immunomodulatory properties signifying it as a potent drug candidate for study. The studies of mechanisms of cell movement are relevant which can be understood by knowing the involvement of genes in an effect of a drug. Although cytotoxicity and anti-proliferative activity of artemisinin is evident, the genes participating in its anti-migratory and reduced invasive effect are not well studied. The present study reports the alteration in the expression of 84 genes involved in cell motility upon artemisinin treatment in MCF-7 breast cancer cells using pathway focused gene expression PCR array. In addition, the effect of artemisinin on epigenetic modifier HDACs is studied.

Methods

We checked the functional stimulus of artemisinin on cell viability, migration, invasion and apoptosis in breast cancerous cell lines. Using qRT-PCR and western blot, we validated the altered expression of relevant genes associated with proliferation, migration, invasion, apoptosis and mammary gland development.

Results

Artemisinin inhibited cell proliferation of estrogen receptor negative breast cancer cells with fewer efficacies in comparison to estrogen receptor positive ones. At the same time, cell viability and proliferation of normal breast epithelial MCF10A cells was un-affected. Artemisinin strongly inhibited cancer cell migration and invasion. Along with orphan nuclear receptors (ERRα, ERRβ and ERRγ), artemisinin altered the ERα/ERβ/PR/Her expression status of MCF-7 cells. The expression of genes involved in the signaling pathways associated with proliferation, migration, invasion and apoptosis was significantly altered which cooperatively resulted into reduced growth promoting activities of breast cancer cells. Interestingly, artemisinin exhibited inhibitory effect on histone deacetylases (HDACs).

Conclusions

Upregulated expression of tumor suppressor genes along with reduced expression of oncogenes significantly associated with growth stimulating signaling pathways in response to artemisinin treatment suggests its efficacy as an effective drug in breast cancer treatment.

Synergistic antitumor effect of 3-bromopyruvate and 5-fluorouracil against human colorectal cancer through cell cycle arrest and induction of apoptosis

3-Bromopyruvic acid (3-BP) is a well-known inhibitor of energy metabolism. It has been proposed as an anticancer agent as well as a chemosensitizer for use in combination with anticancer drugs. 5-Fluorouracil (5-FU) is the first-line chemotherapeutic agent for colorectal cancer; however, most patients develop resistance to 5-FU through various mechanisms. The aim of this study was to investigate whether 3-BP has a synergistic antitumor effect with 5-FU on human colorectal cancer cells. In our study, combined 3-BP and 5-FU treatment upregulated p53 and p21, whereas cyclin-dependent kinase CDK4 and CDK2 were downregulated, which led to G0/G1 phase arrest. Furthermore, there was an increase in reactive oxygen species levels and a decrease in adenosine triphosphate levels. It was also observed that Bax expression increased, whereas Bcl-2 expression reduced, which were indicative of mitochondria-dependent apoptosis. In addition, the combination of 3-BP and 5-FU significantly suppressed tumor growth in the BALB/c mice in vivo. Therefore, 3-BP inhibits tumor proliferation and induces S and G2/M phase arrest. It also exerts a synergistic antitumor effect with 5-FU on SW480 cells.

Luteolin suppresses gastric cancer progression by reversing epithelial-mesenchymal transition via suppression of the Notch signaling pathway

BACKGROUND

Gastric cancer (GC) is one of the most malignant tumors and the second leading cause of cancer-related deaths in the world. Luteolin, a flavonoid present in many fruits and green plants, suppresses cancer progression. The effects of luteolin on GC cells and their underlying mechanisms remain unclear.

METHODS

Effects of luteolin on cell proliferation, migration, invasion, and apoptosis were examined in vitro and in vivo by cell counting kit-8 (CCK-8), transwell assays, and flow cytometry, respectively. Real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blots were performed to evaluate Notch1 signaling and activation of epithelial-mesenchymal transition (EMT) in GC cells treated with or without luteolin. Immunohistochemistry was performed to examine proliferation and Notch1 expression in xenograft tumors.

RESULTS

Luteolin significantly inhibited cell proliferation, invasion, and migration in a dose-dependent and time-dependent manner and promoted cell apoptosis. Luteolin reversed EMT by shrinking the cytoskeleton and by inducing the expression of epithelial biomarker E-cadherin and downregulating the mesenchymal biomarkers N-cadherin, vimentin and Snail. Furthermore, Notch1 signaling was inhibited by luteolin, and downregulation of Notch1 had similar effects as luteolin treatment on cell proliferation, migration, and apoptosis. In addition, luteolin suppressed tumor growth in vivo. A higher expression of Notch1 correlated with a poor overall survival and a poor time to first progression. Furthermore, co-immunoprecipitation analysis revealed that activated Notch1 and β-catenin formed a complex and regulated cell proliferation, migration, and invasion.

CONCLUSIONS

In this study, GC progression was inhibited by luteolin through suppressing Notch1 signaling and reversing EMT, suggesting that luteolin may serve as an effective anti-tumor drug in GC treatment.

Artemisinin and Its Derivatives as a Repurposing Anticancer Agent: What Else Do We Need to Do?

Preclinical investigation and clinical experience have provided evidence on the potential anticancer effect of artemisinin and its derivatives (ARTs) in the recent two decades. The major mechanisms of action of ARTs may be due to toxic-free radicals generated by an endoperoxide moiety, cell cycle arrest, induction of apoptosis, and inhibition of tumor angiogenesis. It is very promising that ARTs are expected to be a new class of antitumor drugs of wide spectrum due to their detailed information regarding efficacy and safety. For developing repurposed drugs, many other characteristics of ARTs should be studied, including through further investigations on possible new pathways of anticancer effects, exploration on efficient and specific drug delivery systems-especially crossing biological barriers, and obtaining sufficient data in clinical trials. The aim of this review is to highlight these achievements and propose the potential strategies to develop ARTs as a new class of cancer therapeutic agents.