Cinobufagin suppresses colorectal cancer angiogenesis by disrupting the endothelial mammalian target of rapamycin/hypoxia-inducible factor 1α axis

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

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

Novel analgesic peptide derived from Cinobufacini injection suppressing inflammation and pain via ERK1/2/COX-2 pathway

Inflammatory pain is a chronic pain caused by peripheral tissue inflammation, seriously impacting the patient's life quality. Cinobufacini injection, as a traditional Chinese medicine injection preparation, shows excellent efficacy in anti-inflammatory and analgesic treatment in patients with advanced tumors. In this study, a novel analgesic peptide CI5 with anti-inflammatory and analgesic bio-functions that naturally presents in Cinobufacini injection and its regulatory mechanism are reported. Our results showed that the administration of CI5 significantly relieved the pain of mice in the acetic acid twisting analgesic model and formalin inflammatory pain model. Furthermore, CI5 effectively reduced the inflammatory cytokines (IL-6, TNF-α and IL-1β) and inflammatory mediator (PGE2) expressions, and prevented the carrageenan-induced paw edema in mice. Further LC-MS/MS results showed the anti-inflammatory and analgesic bio-functions of CI5 depended on its interaction with the Rac-2 protein upstream of ERK1/2 and the inflammatory signaling pathway (ERK1/2/COX-2 axis). In summary, CI5, as a novel natural candidate identified from Cinobufacini injection, showed substantial clinical promise for inflammatory pain treatments.

Cinobufagin disrupts the stability of lipid rafts by inhibiting the expression of caveolin-1 to promote non-small cell lung cancer cell apoptosis

Introduction

The study was designed to explore how cinobufagin (CB) regulates the development of non-small cell lung cancer (NSCLC) cells through lipid rafts.

Material and methods

The effects of CB at gradient concentrations (0, 0.5, 1 and 2 µM) on NSCLC cell viability, apoptosis, reactive oxygen species (ROS) level, phosphorylation of Akt, and apoptosis- and lipid raft-related protein expression were assessed by MTT assay, flow cytometry and Western blot. Cholesterol and sphingomyelin were labeled with BODIPY to evaluate the effect of CB (2 µM) on them. Sucrose density gradient centrifugation was used to extract lipid rafts. The effect of CB on the expression and distribution of caveolin-1 was determined by immunofluorescence, quantitative reverse transcription polymerase chain reaction and Western blot. After overexpression of caveolin-1, the above experiments were performed again to observe whether the regulatory effect of CB was reversed.

Results

CB inhibited NSCLC cell viability while promoting apoptosis and ROS level. CB redistributed the lipid content on the membrane surface and reduced the content of caveolin-1 in the cell membrane. In addition, CB repressed the activation of AKT. However, caveolin-1 overexpression reversed the effects of CB on apoptosis, AKT activation and lipid raft.

Conclusions

CB regulates the activity of Akt in lipid rafts by inhibiting caveolin-1 expression to promote NSCLC cell apoptosis.

Biomimetic Prussian blue nanocomplexes for chemo-photothermal treatment of triple-negative breast cancer by enhancing ICD

Drug-induced immunogenic cell death (ICD) can efficiently inhibit tumor growth and recurrence through the release of tumor-associated antigens which activate both local and systemic immune responses. Pyroptosis has emerged as an effective means for inducing ICD; however, the development of novel pyroptosis inducers to specifically target tumor cells remains a pressing requirement. Herein, we report that Cinobufagin (CS-1), a main ingredient of Chansu, can effectively induce pyroptosis of triple-negative breast cancer (TNBC) cells, making it a potential therapeutic agent for this kind of tumor. However, the application of CS-1 in vivo is extremely limited by the high dosage/long-term usage and non-selectivity caused by systemic toxicity. To address these drawbacks, we developed a new nanomedicine by loading CS-1 into Prussian blue nanoparticles (PB NPs). The nanomedicine can release CS-1 in a photothermal-controlled manner inherited in PB NPs. Furthermore, hybrid membrane (HM) camouflage was adopted to improve the immune escape and tumor-targeting ability of this nanomedicine, as well. In vitro assays demonstrated that the chemo-photothermal combination treatment produced high-level ICD, ultimately fostering the maturation of dendritic cells (DCs). In vivo anti-tumor assessments further indicated that this strategy not only efficiently inhibited primary growth of MDA-MB-231 cells and 4T1 cells-bearing models but also efficiently attenuated distant tumor growth in 4T1 xenograft model. This was mechanistically achieved throuh the promotion of DCs maturation, infiltration of cytotoxic T lymphocyte into the tumor, and the inhibition of Treg cells. In summary, this work provides a novel strategy for efficient TNBC therapy by using nanomaterials-based multimodal nanomedicine through rational design.

Anthracycline chemicals with anthracyclinone structure exert antitumor effects by inhibiting angiogenesis and lymphangiogenesis in a xenografted gastric tumor model

BACKGROUND

It is vital to screen or develop alternative therapeutic drugs with higher curative characteristics and fewer side effects for the clinical treatment of gastric cancer.

METHODS

Gastric cancer cells were exposed to different auramycin G doses while determining the impact on cell viability, migration, and invasion. Then the antitumor effects of auramycin G, 5-fluorouracil (5-Fu) and their combination were evaluated. Furthermore, the molecular mechanisms of angiogenesis and lymphangiogenesis regulated by auramycin G and its analogs were investigated.

RESULTS

Auramycin G inhibited cell viability in a dose-dependent manner, with a 50% inhibitory concentration of 23.72 ± 6.36 mg/L and 32.54 ± 5.91 mg/L for AGS and MGC803 cells, respectively. The migration and invasion of gastric cancer cells were significantly inhibited by 10 mg/L auramycin G, which was consistent with the down-regulation of the VEGFR2-VEGFA-pPI3K-pAkt-pErk1 and VEGFR3-VEGFC-pPI3K-pAkt-pmTOR proteins. Notably, the average tumor weights were significantly reduced in both the auramycin G (2.21 ± 0.45 g) of 50 mg/kg body weight and auramycin G + 5-fluorouracil (5-Fu) groups (1.33 ± 0.28 g), compared with the control (3.73 ± 0.56 g). Considering that auramycin G decreased the growth of blood and lymphatic vessels while reducing the degree of tumor malignancy, it effectively suppressed tumors by regulating the angiogenic and lymphangiogenic pathways.

CONCLUSION

The present study confirmed that auramycin G displayed a prominent antitumor activity in gastric tumor models, both in vitro and in vivo. Moreover, it was confirmed that auramycin G played a specific role in certain gastric cancer cell types, while the mechanism was validated to be associated with angiogenesis- and lymphangiogenesis-related pathway suppression.

Mechanism of the HIF-1α/VEGF/VEGFR-2 pathway in the proliferation and apoptosis of human haemangioma endothelial cells

Haemangiomas (HAs) are prevalent vascular endothelial cell tumours. With respect to the possible involvement of HIF-1α in HAs, we have explored its role in haemangioma endothelial cell (HemEC) proliferation and apoptosis. shRNA HIF-1α and pcDNA3.1 HIF-α were manipulated into HemECs. HIF-α, VEGF, and VEGFR-2 mRNA and protein levels were assessed by qRT-PCR and Western blotting. Cell proliferation and viability, cell cycle and apoptosis, migration and invasion, and ability to form tubular structures were assessed by colony formation assay, CCK-8, flow cytometry, Transwell assay, and tube formation assay. Cell cycle-related protein levels, and VEGF and VEGFR-2 protein interaction were detected by Western blot and immunoprecipitation assays. An Haemangioma nude mouse model was established by subcutaneous injection of HemECs. Ki67 expression was determined by immunohistochemical staining. HIF-1α silencing suppressed HemEC neoplastic behaviour and promoted apoptosis. HIF-1α facilitated VEGF/VEGFR-2 expression and the VEGF had interacted with VEGFR-2 at protein - protein level. HIF-1α silencing arrested HemECs at G0/G1 phase, diminished Cyclin D1 protein level, and elevated p53 protein level. VEGF overexpression partially abrogated the effects of HIF-1α knockdown on inhibiting HemEC malignant behaviours. Inhibiting HIF-1α in nude mice with HAs repressed tumour growth and Ki67-positive cells. Briefly, HIF-1α regulated HemEC cell cycle through VEGF/VEGFR-2, thus promoting cell proliferation and inhibiting apoptosis.

Pharmacological Effects of Cinobufagin

Cinobufagin (CBF) is a bufadienolide, which is a major active ingredient of toad venom. In recent years, CBF has attracted increasing attention due to its highly potent and multiple pharmacological activities. To better understand the status of research on CBF, we collated recent studies on CBF to provide a valuable reference for clinical researchers and practitioners. According to reports, CBF exhibits extensive pharmacological properties, including antitumor, analgesic, cardioprotection, immunomodulatory, antifibrotic, antiviral, and antiprotozoal effects. Studies on the pharmacological activity of CBF have mainly focused on its anticancer activity. It has been demonstrated that CBF has a therapeutic effect on liver cancer, osteosarcoma, melanoma, colorectal cancer, acute promyelocytic leukemia, nasopharyngeal carcinoma, multiple myeloma, gastric cancer, and breast cancer. However, the direct molecular targets of CBF are currently unknown. In addition, there are few reports on toxicological and pharmacokinetic of CBF. Subsequent studies focusing on these aspects will help promote the development and application of CBF in clinical practice.

Cinobufagin: a promising therapeutic agent for cancer

OBJECTIVES

Cinobufagin is a natural active ingredient isolated from the traditional Chinese medicine Venenum Bufonis (Chinese: Chansu), which is the dried secretion of the postauricular gland or skin gland of the Bufo gargarizans Cantor or Bufo melanostictus Schneider. There is increasing evidence indicating that cinobufagin plays an important role in the treatment of cancer. This article is to review and discuss the antitumor pharmacological effects and mechanisms of cinobufagin, along with a description of its toxicity and pharmacokinetics.

METHODS

The public databases including PubMed, China National Knowledge Infrastructure and Elsevier were referenced, and 'cinobufagin', 'Chansu', 'Venenum Bufonis', 'anticancer', 'cancer', 'carcinoma', and 'apoptosis' were used as keywords to summarize the comprehensive research and applications of cinobufagin published up to date.

KEY FINDINGS

Cinobufagin can induce tumour cell apoptosis and cycle arrest, inhibit tumour cell proliferation, migration, invasion and autophagy, reduce angiogenesis and reverse tumour cell multidrug resistance, through triggering DNA damage and activating the mitochondrial pathway and the death receptor pathway.

CONCLUSIONS

Cinobufagin has the potential to be further developed as a new drug against cancer.

Biomimetic oxygen-boosted hybrid membrane nanovesicles as the treatment strategy for ischemic stroke with the concept of the neurovascular unit

The pathogenesis of ischemic cerebrovascular disease has revealed that ischemic stroke often leads to deprivation of oxygen, blood-brain barrier (BBB) damage and enhanced inflammatory activation, eventually causing severe brain tissue damage. Herein, we prepared hybrid membrane nanovesicles (YC-1@[RBC-PL] NVs) composed of red blood cell (RBC) membrane and platelet (PL) membrane encapsulating hypoxia inducible factor-1α (HIF-1α) inhibitor YC-1 for contributing to the protection of the neurovascular unit (NVU) in ischemic stroke. YC-1@[RBC-PL] NVs targeted the ischemic brain by the thrombus targeting properties of PL membrane and relieved the hypoxia inside ischemic brain in the presence of YC-1 and catalase in YC-1@[RBC-PL] NVs. Finally, YC-1@[RBC-PL] NVs attenuated ischemic injury to NVU by reducing infarct volume, preserving BBB integrity, and blocking activation of astrocyte and microglia in a middle cerebral artery occlusion/reperfusion (MCAO/R) model.

Toad venom-derived bufadienolides and their therapeutic application in prostate cancers: Current status and future directions

Cancer is the second leading cause of death worldwide. Specially, the high incidence rate and prevalence of drug resistance have rendered prostate cancer (PCa) a great threat to men’s health. Novel modalities with different structures or mechanisms are in urgent need to overcome these two challenges. Traditional Chinese medicine toad venom-derived agents (TVAs) have shown to possess versatile bioactivities in treating certain diseases including PCa. In this work, we attempted to have an overview of bufadienolides, the major bioactive components in TVAs, in the treatment of PCa in the past decade, including their derivatives developed by medicinal chemists to antagonize certain drawbacks of bufadienolides such as innate toxic effect to normal cells. Generally, bufadienolides can effectively induce apoptosis and suppress PCa cells in-vitro and in-vivo, majorly mediated by regulating certain microRNAs/long non-coding RNAs, or by modulating key pro-survival and pro-metastasis players in PCa. Importantly, critical obstacles and challenges using TVAs will be discussed and possible solutions and future perspectives will also be presented in this review. Further in-depth studies are clearly needed to decipher the mechanisms, e.g., targets and pathways, toxic effects and fully reveal their application. The information collected in this work may help evoke more effects in developing bufadienolides as therapeutic agents in PCa.

Cinobufagin induces acute promyelocytic leukaemia cell apoptosis and PML-RARA degradation in a caspase-dependent manner by inhibiting the β-catenin signalling pathway

CONTEXT

Acute promyelocytic leukaemia (APL) is a malignant hematological tumour characterized by the presence of promyelocytic leukaemia-retinoic acid receptor A (PML-RARA) fusion protein. Cinobufagin (CBG) is one of the main effective components of toad venom with antitumor properties. However, only a few reports regarding the CBG treatment of APL are available.

OBJECTIVE

We explored the effect and mechanism of action of CBG on NB4 and NB4-R1 cells.

MATERIALS AND METHODS

We evaluated the viability of NB4 and NB4-R1 cells treated with 0, 20, 40, and 60 nM CBG for 12, 24, and 48 h. After treatment with CBG for 24 h, Bcl-2 associated X (Bax), B-cell lymphoma 2 (Bcl-2), β-catenin, cyclin D1, and c-myc expression was detected using western blotting and real-time polymerase chain reaction. Caspase-3 and PML-RARA expression levels were detected using western blotting.

RESULTS

CBG inhibited the viability of NB4 and NB4-R1 cells. The IC₅₀ values of NB4 and NB4-R1 cells treated with CBG for 24 h were 45.2 nM and 37.9 nM, respectively. CBG induced NB4 and NB4-R1 cell apoptosis and PML-RARA degradation in a caspase-dependent manner and inhibited the β-catenin signalling pathway.

DISCUSSION AND CONCLUSION

CBG induced NB4 and NB4-R1 cell apoptosis and PML-RARA degradation in a caspase-dependent manner by inhibiting the β-catenin signalling pathway. This study proposes a novel treatment strategy for patients with APL, particularly those with ATRA-resistant APL.

A research update on the antitumor effects of active components of Chinese medicine ChanSu

Clinical data show that the incidence and mortality rates of cancer are rising continuously, and cancer has become an ongoing public health challenge worldwide. Excitingly, the extensive clinical application of traditional Chinese medicine may suggest a new direction to combat cancer, and the therapeutic effects of active ingredients from Chinese herbal medicine on cancer are now being widely studied in the medical community. As a traditional anticancer Chinese medicine, ChanSu has been clinically applied since the 1980s and has achieved excellent antitumor efficacy. Meanwhile, the ChanSu active components (e.g., telocinobufagin, bufotalin, bufalin, cinobufotalin, and cinobufagin) exert great antitumor activity in many cancers, such as breast cancer, colorectal cancer, hepatocellular carcinoma and esophageal squamous cell carcinoma. Many pharmaceutical scientists have investigated the anticancer mechanisms of ChanSu or the ChanSu active components and obtained certain research progress. This article reviews the research progress and antitumor mechanisms of ChanSu active components and proposes that multiple active components of ChanSu may be potential anticancer drugs.

Bioactive constituents of animal-derived traditional Chinese medicinal materials for breast cancer: opportunities and challenges

Breast cancer is globally the most common invasive cancer in women and remains one of the leading causes of cancer-related deaths. Surgery, radiotherapy, chemotherapy, immunotherapy, and endocrine therapy are currently the main treatments for this cancer type. However, some breast cancer patients are prone to drug resistance related to chemotherapy or immunotherapy, resulting in limited treatment efficacy. Consequently, traditional Chinese medicinal materials (TCMMs) as natural products have become an attractive source of novel drugs. In this review, we summarized the current knowledge on the active components of animal-derived TCMMs, including Ophiocordycepssinensis-derived cordycepin, the aqueous and ethanolic extracts of O.sinensis, norcantharidin (NCTD), Chansu, bee venom, deer antlers, Ostreagigas, and scorpion venom, with reference to marked anti-breast cancer effects due to regulating cell cycle arrest, proliferation, apoptosis, metastasis, and drug resistance. In future studies, the underlying mechanisms for the antitumor effects of these components need to be further investigated by utilizing multi-omics technologies. Furthermore, large-scale clinical trials are necessary to validate the efficacy of bioactive constituents alone or in combination with chemotherapeutic drugs for breast cancer treatment.

Combining Network Pharmacology and Experimental Validation to Study the Action and Mechanism of Water extract of Asparagus Against Colorectal Cancer

Asparagus (ASP) is a well-known traditional Chinese medicine with nourishing, moistening, fire-clearing, cough-suppressing, and intestinal effects. In addition, it exerts anti-inflammatory, antioxidant, anti-aging, immunity-enhancing, and anti-tumor pharmacological effect. The anti-tumor effect of ASP has been studied in hepatocellular carcinoma. However, its action and pharmacological mechanism in colorectal cancer (CRC) are unclear. The present study aimed to identify the potential targets of ASP for CRC treatment using network pharmacology and explore its possible therapeutic mechanisms using in vitro and in vivo experiments. The active compounds and potential targets of ASP were obtained from the TCMSP database, followed by CRC-related target genes identification using GeneCards and OMIM databases, which were matched with the potential targets of ASP. Based on the matching results, potential targets and signaling pathways were identified by protein-protein interaction (PPI), gene ontology (GO) functions, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Finally, in vitro and in vivo experiments were performed to further validate the anti-cancer effects of ASP on CRC. Network pharmacology analysis identified nine active components from ASP from the database based on oral bioavailability and drug similarity index, and 157 potential targets related to ASP were predicted. The PPI network identified tumor protein 53 (TP53), Fos proto-oncogene, AP-1 transcription factor subunit (FOS), and AKT serine/threonine kinase 1 (AKT1) as key targets. GO analysis showed that ASP might act through response to wounding, membrane raft, and transcription factor binding. KEGG enrichment analysis revealed that ASP may affect CRC through the phosphatidylinositol-4,5-bisphosphate 3-kinase PI3K/AKT/mechanistic target of rapamycin kinase (mTOR) signaling pathway. In vitro, ASP inhibited cell proliferation, migration, and invasion of HCT116 and LOVO cells, and caused G0/G1 phase arrest and apoptosis in CRC cells. In vivo, ASP significantly inhibited the growth of CRC transplanted tumors in nude mice. Furthermore, pathway analysis confirmed that ASP could exert its therapeutic effects on CRC by regulating cell proliferation and survival through the PI3K/AKT/mTOR signaling pathway. This study is the first to report the potential role of ASP in the treatment of colorectal cancer.

Cinobufagin inhibits proliferation of acute myeloid leukaemia cells by repressing c-Myc pathway-associated genes

Cinobufagin is a cardiotoxic bufanolide steroid secreted by the Asiatic toad, Bufo gargarizans. Bufanolides inhibit Na⁺/K⁺ ATPase and have similar effects as cardiac glycosides, such as digitoxin or ouabain derived from toxic herbs. Recently, the anti-cancer effects of bufanolides have gained attention, however the underlying molecular mechanisms remain unclear. Selecting cinobufagin as a candidate anti-leukaemia agent, we here conducted transcriptomic analyses on the effect of cinobufagin on human acute myeloid leukaemia (AML) cell lines, HL60 and Kasumi-1. Flow cytometry analysis showed that cinobufagin induced apoptosis in both cell lines. RNA-sequencing (RNA-seq) of the two cell lines treated with cinobufagin revealed commonly downregulated genes with enrichment in the term "Myc active pathway" according to Gene Ontology (GO) analysis. Gene Set Enrichment Analysis (GSEA) of genes downregulated by cinobufagin also showed "MYC_TARGETS_V2" with the highest normalised enrichment score (NES) in both cell lines. In contrast, hallmarks such as "TNFA_SIGNALING_VIA_NFKB", "APOPTOSIS", and "TGF_BETA_SIGNALING" were significantly enriched as upregulated gene sets. Epigenetic analysis using chromatin immunoprecipitation and sequencing (ChIP-seq) confirmed that genes encoding cell death-related signalling molecules were upregulated by gain of H3K27ac, whereas downregulation of c-Myc-related genes was not accompanied by H3K27ac alteration. Cinobufagin is an anti-proliferative natural compound with c-Myc-inhibiting and epigenetic-modulating activity in acute myeloid leukaemia.

Cinobufagin Is a Selective Anti-Cancer Agent against Tumors with EGFR Amplification and PTEN Deletion

Glioblastoma multiforme (GBM) is the most common and malignant brain tumor, and almost half of the patients carrying EGFR-driven tumor with PTEN deficiency are resistant to EGFR-targeted therapy. EGFR amplification and/or mutation is reported in various epithelial tumors. This series of studies aimed to identify a potent compound against EGFR-driven tumor. We screened a chemical library containing over 600 individual compounds purified from Traditional Chinese Medicine against GBM cells with EGFR amplification and found that cinobufagin, the major active ingredient of Chansu, inhibited the proliferation of EGFR amplified GBM cells and PTEN deficiency enhanced its anti-proliferation effects. Cinobufagin also strongly inhibited the proliferation of carcinoma cell lines with wild-type or mutant EGFR expression. In contrast, the compound only weakly inhibited the proliferation of cancer cells with low or without EGFR expression. Cinobufagin blocked EGFR phosphorylation and its downstream signaling, which additionally induced apoptosis and cytotoxicity in EGFR amplified cancer cells. In vivo, cinobufagin blocked EGFR signaling, inhibited cell proliferation, and elicited apoptosis, thereby suppressing tumor growth in both subcutaneous and intracranial U87MG-EGFR xenograft mouse models and increasing the median survival of nude mice bearing intracranial U87MG-EGFR tumors. Cinobufagin is a potential therapeutic agent for treating malignant glioma and other human cancers expressing EGFR.

Small molecule targeting topoisomerase 3β for cancer therapy

DNA topoisomerases are proved cancer therapeutic targets with clinically successful anticancer drugs for decades. However, the role of RNA topoisomerase (TOP3β) remained mysterious especially in cancer, and no targeted agent has been reported yet. In a target identification assay of anti-cancer compound using a modified DrugTargetSeqR strategy, mutation of TOP3B was detected in cancer cells acquired resistance to cinobufagin (CBG), a key compound of Huachansu that has been approved for cancer therapy in China. We demonstrated that CBG directly engaged with TOP3β, and promoted TOP3β depletion in wildtype but not mutant cancer cells. Notably, knockout of TOP3β in cancer cells significantly reduced tumor enlargement but not initiation, and inhibited colony formation upon nutrient deprivation. We also demonstrated that CBG induced formation of stress granule, RNA-loop and asymmetric DNA damages in cancer cells, and all these phenotypes were significantly attenuated in TOP3B knockout cells. Of note, examination of a panel of cancer cell lines revealed associations among cell growth inhibition and induction of DNA damage as well as TOP3B depletion upon CBG treatment. Our findings not only highlighted TOP3β as a promising therapeutic target of cancer, but also identified CBG as a lead chemical inhibitor of TOP3β for cancer therapy.

A hybrid membrane coating nanodrug system against gastric cancer via the VEGFR2/STAT3 signaling pathway

Although drug combination has proved to be an efficient strategy for clinic gastric cancer therapy, how to further improve their bioavailability and reduce the side effects are still challenges due to the low solubility and untargeted ability of drugs. Recently, newly emerging nanotechnology has provided an alternative for constructing new drug delivery systems with high targeting ability and solubility. In this study, a pH-responsive liposome (Liposome-PEO, LP) loaded with apatinib (AP) and cinobufagin (CS-1) was used for combinational therapy against gastric cancer after coating with a hybrid membrane (R/C). The results indicated that the constructed nanocomplex LP-R/C@AC not only efficiently killed tumor cells in vitro by inducing apoptosis, autophagy, and pyroptosis, but also significantly inhibited tumor invasion and metastasis via the VEGFR2/STAT3 pathway. Moreover, it showed stronger anti-tumor activity in gastric cancer-bearing mouse models, as compared to the sole drugs. A naturally-derived hybrid cell membrane coating bestowed nanocomplexes with enhanced biointerfacing including prolonged circulation time and targeting ability.

Natural products as potent inhibitors of hypoxia-inducible factor-1α in cancer therapy

Hypoxia is a prominent feature of tumors. Hypoxia-inducible factor-1α (HIF-1α), a major subunit of HIF-1, is overexpressed in hypoxic tumor tissues and activates the transcription of many oncogenes. Accumulating evidence has demonstrated that HIF-1α promotes tumor angiogenesis, metastasis, metabolism, and immune evasion. Natural products are an important source of antitumor drugs and numerous studies have highlighted the crucial role of these agents in modulating HIF-1α. The present review describes the role of HIF-1α in tumor progression, summarizes natural products used as HIF-1α inhibitors, and discusses the potential of developing natural products as HIF-1α inhibitors for the treatment of cancer.

Toad venom: A comprehensive review of chemical constituents, anticancer activities, and mechanisms

Toad venom, a traditional natural medicine, has been used for hundreds of years in China for treating different diseases. Many studies have been performed to elucidate the cardiotonic and analgesic activities of toad venom. Until the last decade, an increasing number of studies have documented that toad venom is a source of lead compound(s) for the development of potential cancer treatment drugs. Research has shown that toad venom contains 96 types of bufadienolide monomers and 23 types of indole alkaloids, such as bufalin, cinobufagin, arenobufagin, and resibufogenin, which exhibit a wide range of anticancer activities in vitro and, in particular, in vivo for a range of cancers. The main antitumor mechanisms are likely to be apoptosis or/and autophagy induction, cell cycle arrest, cell metastasis suppression, reversal of drug resistance, or growth inhibition of cancer cells. This review summarizes the chemical constituents of toad venom, analyzing their anticancer activities and molecular mechanisms for cancer treatments. We also outline the importance of further studies regarding the material basis and anticancer mechanisms of toad venom.

Histone Demethylase KDM3A Promotes Cervical Cancer Malignancy Through the ETS1/KIF14/Hedgehog Axis

Background

Lysine demethylase 3A (KDM3A) has been increasingly recognized as an important epigenetic regulator involved in cancer development. This study aims to explore the relevance of KDM3A to cervical cancer (CC) progression and the molecules involved.

Materials and Methods

Tumor and the adjacent tissues from CC patients were collected. KDM3A expression in tissues and CC cell lines and its correlation with the survival and prognosis of patients were determined. Malignant potentials of CC cells and the angiogenesis ability of HUVECs were measured to evaluate the function of KDM3A on CC progression. The interactions among KDM3A, H3K9me2 and ETS1, and the binding between ETS1 and KIF14 were validated through ChIP and luciferase assays. Altered expression of ETS1 and KIF14 was introduced to explore their roles in CC development.

Results

KDM3A was abundantly expressed in CC tissues and cells and linked to dismal prognosis of CC patients. Knockdown of KDM3A suppressed malignant behaviors of CC cells. KDM3A was found to increase ETS1 expression through the demethylation of H3K9me2. Overexpression of ETS1 blocked the inhibiting roles of sh-KDM3A. ETS1 could bind to the promoter region of KIF14 to trigger its transcription. Overexpression ofKIF14aggravated the malignant behaviors of CC cells and the angiogenesis ability of HUVECs, and it activated the Hedgehog signaling pathway. Artificial activation of Hedgehog by Sag1.5 diminished the effects of sh-KDM3A. These changes were reproduced in vivo.

Conclusion

This study evidenced that KDM3A promotes ETS1-mediated KIF14 transcription to promote CC progression with the involvement of the Hedgehog activation.

Cinobufagin Suppresses Melanoma Cell Growth by Inhibiting LEF1

Constitutive activation of the β-catenin dependent canonical Wnt signaling pathway, which enhances tumor growth and progression in multiple types of cancer, is commonly observed in melanoma. LEF1 activates β-catenin/TCF4 transcriptional activity, promoting tumor growth and progression. Although several reports have shown that LEF1 is highly expressed in melanoma, the functional role of LEF1 in melanoma growth is not fully understood. While A375, A2058, and G361 melanoma cells exhibit abnormally high LEF1 expression, lung cancer cells express lower LEF1 levels. A luciferase assay-based high throughput screening (HTS) with a natural compound library showed that cinobufagin suppressed β-catenin/TCF4 transcriptional activity by inhibiting LEF1 expression. Cinobufagin decreases LEF1 expression in a dose-dependent manner and Wnt/β-catenin target genes such as Axin-2, cyclin D1, and c-Myc in melanoma cell lines. Cinobufagin sensitively attenuates cell viability and induces apoptosis in LEF1 expressing melanoma cells compared to LEF1-low expressing lung cancer cells. In addition, ectopic LEF1 expression is sufficient to attenuate cinobufagin-induced apoptosis and cell growth retardation in melanoma cells. Thus, we suggest that cinobufagin is a potential anti-melanoma drug that suppresses tumor-promoting Wnt/β-catenin signaling via LEF1 inhibition.

Anticancer Effects of Fufang Yiliu Yin Formula on Colorectal Cancer Through Modulation of the PI3K/Akt Pathway and BCL-2 Family Proteins

Colorectal cancer (CRC) is one of the most common malignant tumors in China. Fufang Yiliu Yin (FYY) is a traditional Chinese medicine formula used in clinical practice for cancer treatment, but its effectiveness and mechanism of action in human CRC are unclear. In this study, we investigated the antitumor effect of FYY on HCT116 and SW480 human CRC cell lines in vitro and evaluated the underlying molecular mechanism. A subcutaneous xenograft mouse model was used to confirm the antitumor effect in vivo. The components and targets of FYY were collected from the Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) database. CRC targets were collected via the GeneCards and OMIM databases. Protein–protein interactions were explored using the STRING platform. Cytoscape was used to construct drug–disease–target networks. KEGG and GO analyses were performed to investigate common FYY and CRC targets. FYY significantly inhibited cell proliferation and induced HCT116 and SW480 cell apoptosis. Cell proliferation was blocked at the G0/G1 phase, while cell apoptosis was promoted at the early stage. According to the network pharmacological analysis, quercetin and kaempferol were the most bioactive compounds of FYY. The key targets of FYY were cyclin-D1, MAPK8, and EGFR. GO analysis showed that core targets included the apoptotic signaling pathway, response to steroid hormone, and cellular response to organic cyclic compound. The KEGG pathway analysis showed that FYY may affect CRC through the PI3K/Akt pathway. In vitro, FYY significantly inhibited tumor growth. Pathway analysis confirmed that FYY induced cell apoptosis by modulating PI3K/Akt signaling and BCL-2 family proteins. Hence, our findings indicate that FYY may be a promising adjuvant therapy for CRC.

Molecular mechanisms of bufadienolides and their novel strategies for cancer treatment

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

Biology and Therapeutic Targets of Colorectal Serrated Adenocarcinoma; Clues for a Histologically Based Treatment against an Aggressive Tumor

Serrated adenocarcinoma (SAC) is a tumor recognized by the WHO as a histological subtype accounting for around 9% of colorectal carcinomas. Compared to conventional carcinomas, SACs are characterized by a worse prognosis, weak development of the immune response, an active invasive front and a frequent resistance to targeted therapy due to a high occurrence of KRAS or BRAF mutation. Nonetheless, several high-throughput studies have recently been carried out unveiling the biology of this cancer and identifying potential molecular targets, favoring a future histologically based treatment. This review revises the current evidence, aiming to propose potential molecular targets and specific treatments for this aggressive tumor.

Chrysophanol exhibits anti-cancer activities in lung cancer cell through regulating ROS/HIF-1a/VEGF signaling pathway

In the present study, we explored the anti-tumor and anti-angiogenesis effects of chrysophanol, and to investigate the underlying mechanism of the chrysophanol on anti-tumor and anti-angiogenesis in human lung cancer. The viability of cells was measured by CCK-8 assay, cell apoptosis was measured by Annexin-FITC/PI staining assay, and the cell migration and invasion were analyzed by wound-healing assay and transwell assay. ROS generation and mitochondrial membrane potential were analyzed by DCFH-DA probe and mitochondrial staining kit. Angiogenesis was analyzed by tube formation assay. The expression of CD31 was analyzed by immunofluorescence. The levels of proteins were measured by western blot assay. The anti-tumor effects of chrysophanol in vivo were detected by established xenograft mice model. In this study, we found that the cell proliferation, migration, invasion, tube formation, the mitochondrial membrane potential, and the expression of CD31 were inhibited by chrysophanol in a dose-dependent manner, but cell apoptotic ratios and ROS levels were increased by chrysophanol in a dose-dependent manner. Furthermore, the effects of chrysophanol on A549, H738, and HUVEC cell apoptotic rates were reversed by the ROS inhibitor NAC. Besides, the effects of chrysophanol on HUVEC cell tube formation were reversed by the HIF-1α inhibitor KC7F2 and the VEGF inhibitor axitinib in vitro. Moreover, tumor growth was reduced by chrysophanol, and the expression of CD31, CD34, and angiogenin was suppressed by chrysophanol in vivo. Our finding demonstrated that chrysophanol is a highly effective and low-toxic drug for inhibition of tumor growth especially in high vascularized lung cancer.

Cinobufagin suppresses colorectal cancer angiogenesis by disrupting the endothelial mammalian target of rapamycin/hypoxia-inducible factor 1α axis

Inducing angiogenesis is a hallmark of cancers that sustains tumor growth and metastasis. Neovascularization is a surprisingly early event during the multistage progression of cancer. Cinobufagin, an important bufadienolide originating from Chan Su, has been clinically used to treat cancer in China since the Tang dynasty. Here, we show that cinobufagin suppresses colorectal cancer (CRC) growth in vivo by downregulating angiogenesis. The hierarchized neovasculature is significantly decreased and the vascular network formation is disrupted in HUVEC by cinobufagin in a dose‐dependent way. Endothelial apoptosis is observed by inducing reactive oxygen species (ROS) accumulation and mitochondrial dysfunction which can be neutralized by N‐acetyl‐l‐cysteine (NAC). Expression of hypoxia‐inducible factor 1α (HIF‐1α) is reduced and phosphorylation of mTOR at Ser2481 and Akt at Ser473 is downregulated in HUVEC. Endothelial apoptosis is triggered by cinobufagin by stimulation of Bax and cascade activation of caspase 9 and caspase 3. Increased endothelial apoptosis rate and alterations in the HIF‐1α/mTOR pathway are recapitulated in tumor‐bearing mice in vivo. Further, the anti‐angiogenesis function of cinobufagin is consolidated based on its pro‐apoptotic effects on an EOMA‐derived hemangioendothelioma model. In conclusion, cinobufagin suppresses tumor neovascularization by disrupting the endothelial mTOR/HIF‐1α pathway to trigger ROS‐mediated vascular endothelial cell apoptosis. Cinobufagin is a promising natural anti‐angiogenetic drug that has clinical translation potential and practical application value.