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

Cinobufacini enhances the therapeutic response of 5-Fluorouracil against gastric cancer by targeting cancer stem cells via AKT/GSK-3β/β-catenin signaling axis

BACKGROUND

Gastric cancer stem cells (GCSCs) play crucial role in the development, recurrence, and resistance of gastric cancer (GC). Cinobufacini, a traditional Chinese medicine, offers significant advantages in improving tumor therapy. However, pre-clinical investigation into the antitumor effect and mechanism of Cinobufacini on GC is still lacking. Additionally, it has not been reported whether Cinobufacini is related to cancer stem cells (CSCs).

METHODS

The CCK-8, clone formation, EdU staining, transwell and wound healing experiments were performed to assess the cell toxicity of Cinobufacini and demonstrate the preventive effects of Cinobufacini on proliferation, invasion, and migration of GC cells. Elucidating the underlying mechanism of Cinobufacini in GC based on the transcriptome sequencing. Flow cytometry assays, sphere formation assays, subcutaneous xenograft model in nude mice, and immunofluorescent staining have been used to investigate whether the anti-GC effect of Cinobufacini is associated with GCSCs and enhancing therapeutic response to 5-Fluorouracil (5-FU).

RESULTS

Cinobufacini exerts minimal impact on normal human gastric epithelium cell GES-1, while significantly suppressing the proliferation, invasion, and migration of GC cell lines. Additionally, Cinobufacini attenuates the stemness of GCSCs by disrupting the AKT/GSK-3β/β-catenin signaling cascade. Moreover, Cinobufacin enhances the anti-tumor effects of 5-FU against GCSCs by reducing in vitro sphere formation and inhibiting subcutaneous graft tumor growth in vivo.

CONCLUSIONS

Cinobufacini enhances the therapeutic response of 5-FU against GC by targeting CSCs via AKT/GSK-3β/β-catenin signaling axis. Our findings offer a crucial insight into the molecular mechanism of Cinobufacini's anticancer activity in GC.

Urolithin C suppresses colorectal cancer progression via the AKT/mTOR pathway

Urolithin families are gut-microbial metabolites of ellagic acid (EA). Although urolithin A (UA) and urolithin B (UB) were reported to have antiproliferative activities in cancer cells, the role and related mechanisms of urolithin C (UC) in colorectal cancer (CRC) have not yet been clarified. In this study, we assess the antitumor activities of UC in vitro and in vivo and further explore the underlying mechanisms in CRC cell lines. We found that UC inhibited the proliferation and migration of CRC cells, induced apoptosis, and arrested the cell cycle at the G2/M phase in vitro, and UC inhibited tumor growth in a subcutaneous transplantation tumor model in vivo. Mechanically, UC blocked the activation of the AKT/mTOR signaling pathway by decreasing the expression of Y-box binding protein 1(YBX1). The AKT agonist SC79 could reverse the suppression of cell proliferation in UC-treated CRC cells. In conclusion, our research revealed that UC could prevent the progression of CRC by blocking AKT/mTOR signaling, suggesting that it may have potential therapeutic values.

Identification of potential anti-tumor targets and mechanisms of HuaChanSu injection using network pharmacology and cytological experiments in Breast cancer

HuaChanSu (HCS) or Cinobufacini injection is an aqueous extract of the dried skin of Bufo bufo gargarigans, and has anti-tumor effects. The aim of this study was to evaluate the possible therapeutic effect of HCS against breast cancer (BRCA) using cytology, network pharmacology, and molecular biology approaches. The half-inhibitory concentration (IC50) of HCS in the BRCA cells was determined by cytotoxicity assay, and were accordingly treated with high and low doses HCS in the TUNEL and scratch assays. The potential targets of HCS in the BRCA cells were identified through functional enrichment analysis and protein-protein interaction (PPI) networks, and verified by molecular docking. The expression levels of key signaling pathways-related proteins in HCS-treated BRCA cells by western blotting. HCS inhibited the proliferation and migration of MCF-7 and MDA-MB-231 cells, and induced apoptosis in a dose-dependent manner. Furthermore, we screened 289 core HCS targets against BRCA, which were primarily enriched in the PI3K-AKT, MAPK chemokines, and other. signaling pathways. In addition, PIK3CA, PIK3CD, and MTOR were confirmed as HCS targets by molecular docking. Consistent with this, we observed a reduction in the expression levels of phosphorylated PI3K, AKT, and MTOR in the HCS-treated BRCA cells. Taken together, our findings suggest that HCS inhibits the growth of BRCA cells by targeting the PI3K-AKT pathway, and warrants further investigation as a therapeutic agent for treating patients with BRCA.

Negative regulation of thyroid adenoma-associated protein (THADA) in the cardiac glycoside-induced anti-cancer effect

Cardiac glycosides, known as inhibitors of Na+,K+-ATPase, have anti-cancer effects such as suppression of cancer cell proliferation and induction of cancer cell death. Here, we examined the signaling pathway elicited by cardiac glycosides in the human hepatocellular carcinoma HepG2 cells and human epidermoid carcinoma KB cells. Three kinds of cardiac glycosides (ouabain, oleandrin, and digoxin) inhibited the cancer cell proliferation and decreased the expression level of thyroid adenoma-associated protein (THADA). Interestingly, the knockdown of THADA inhibited cancer cell proliferation, and the proliferation was significantly rescued by re-expression of THADA in the THADA-knockdown cells. In addition, the THADA-knockdown markedly decreased the expression level of L-type amino acid transporter LAT1. Cardiac glycosides also reduced the LAT1 expression. The LAT1 inhibitor, JPH203, significantly weakened the cancer cell proliferation. These results suggest that the binding of cardiac glycosides to Na+,K+-ATPase negatively regulates the THADA-LAT1 pathway, exerting the anti-proliferative effect in cancer cells.

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

Background

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

Methods

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

Results

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

Conclusion

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

Efficacy and Safety of Hepatic Arterial Infusion Therapy with Cinobufacini in Advanced Hepatocellular Carcinoma with Macrovascular Invasion: A Retrospective Cohort Study

Background

The presence of macrovascular invasion (MVI) is associated with poor prognosis in advanced hepatocellular carcinoma (HCC). This study aims to evaluate the efficacy and safety of Cinobufacini therapy via hepatic arterial infusion (HAI) in advanced HCC patients with MVI.

Methods

The clinical records of 130 consecutive patients with unresectable advanced HCC and MVI who had received Cinobufacini or cisplatin plus 5-fluorouracil (CF) treatment via HAI were retrospectively analyzed. The therapeutic efficacy, overall survival (OS), progression-free survival (PFS), and adverse events were compared between the two treatment groups.

Results

The Cinobufacini group demonstrated significant curative effects on treatment via HAI compared with the CF group, including the objective response rate (44.9% vs 27.9%, P=0.048), the median OS (14.8 months vs 11.1 months, P=0.010), and the median PFS (10.3 months vs 6.0 months, P=0.006). Result in subgroup analysis of portal vein invasion grade supported the efficacy in Cinobufacini treatment, especially in the median OS of Vp1-2 (18.3 months vs 14.3 months, P=0.043) and Vp3 (15.0 months vs 11.4 months, P=0.046), as well as the median PFS of Vp1-2 (14.8 months vs 10.2 months, P=0.028) and Vp3 (10.8 months vs 6.6 months, P=0.033) compared with CF treatment. Cox proportional hazards model and forest plot analysis of factors confirmed the survival benefit from HAI with Cinobufacini over CF (hazard ratio [HR], 0.61; 95% CI: 0.40-0.91; P=0.010). Multivariable analysis identified portal vein invasion grade (Vp4; HR, 1.78; 95% CI: 1.03-2.16; P=0.032) and AFP (>1000; HR, 1.61; 95% CI: 1.08-1.91; P=0.039) as the independent factors for prognosis. Moreover, the total incidence of adverse events in the Cinobufacini group was significantly lower than in the CF group (60.9% vs 82.0%, P=0.009).

Conclusion

Cinobufacini therapy via HAI is a viable strategy for curing advanced HCC with MVI, due to prolonged survival and a superior safety profile.

Overexpression of Nrf2 reverses ferroptosis induced by Arenobufagin in gastric cancer

Arenobufagin (ArBu) is a natural monomer extracted and isolated from the secretion of the Chinese toad, also known as toad venom. This compound exerts anti-tumor effects by promoting apoptosis in tumor cells, inhibiting tumor angiogenesis, and preventing the invasion and migration of tumor cells. However, their impact on ferroptosis in tumor cells has yet to be fully confirmed. In this study, we established a subcutaneous transplant tumor model in nude mice to investigate the inhibitory effect of ArBu on gastric cancer cells (MGC-803) and the safety of drug delivery. in vitro experiments, we screened the most sensitive cancer cell lines using the MTT method and determined the response of ArBu to cell death. Use flow cytometry to measure cytoplasmic and lipid reactive oxygen species (ROS) levels. Determine the expression levels of ferritin-related proteins through Western blot experiments. In addition, a MGC-803 cell model overexpressing Nrf2 was created using lentiviral transfection to investigate the role of ArBu in inducing ferroptosis in cancer cells. Our research findings indicate that ArBu inhibits the proliferation of MGC-803 cells and is linked to ferroptosis. In summary, our research findings indicate that ArBu is a potential anti-gastric cancer drug that can induce ferroptosis in human cancer cells through the Nrf2/SLC7A11/GPX4 pathway.

HuaChanSu suppresses the growth of hepatocellular carcinoma cells by interfering with pentose phosphate pathway through down-regulation of G6PD enzyme activity and expression

HuaChanSu is active water extracts from the skin of Bufo bufo gargarizans Cantor. It has been already used to treat clinical cancers including HCC (Hepatocellular carcinoma, HCC), however, the molecular mechanisms under HuaChanSu's anti-cancer effects remain unclear. PPP (Pentose phosphate pathway, PPP), the major source of ribose and NADPH (Nicotinamide adenine dinucleotide phosphate, NADPH), is always over-activated and particularly critical for tumor cells growth. In this study, firstly, we illustrate that HuaChanSu restrains the growth of human hepatoma cells. More importantly, we demonstrate that the expression of G6PD (Glucose-6-phosphate dehydrogenase, G6PD), the first rate-limiting enzyme of the PPP, is restrained in human hepatoma cells after treatment with HuaChanSu. Additionally, our results show that G6PD enzyme activity and dimer formation are inhibited by HuaChanSu. Furthermore, we find that HuaChanSu could inhibit NADPH production and nucleotide level. In addition, we identify that expression of PLK1 (Polo-like kinase 1, PLK1) is also reduced in response to HuaChanSu, and knockdown of PLK1 restrains enzyme activity and dimer formation of G6PD, but has no effect on G6PD protein level. Subsequently, we demonstrate that inhibition of G6PD could restrain the proliferation of tumor cells and enhance the inhibitory effect of HuaChanSu on cell proliferation of human hepatoma cells. In conclusion, for the first time, our study reveals that HuaChanSu interferes with PPP via suppression of G6PD expression and enzyme activity to restrain growth of tumor cells, and these results provide a novel insight for the anti-hepatoma mechanisms of HuaChanSu and promote the innovation of the research model of TCM. Moreover, the development of drugs targeting abnormal tumor metabolism is currently a hot topic, our works provide theoretical support for further drug development from HuaChanSu, meanwhile, the revelation of the new molecular mechanism also provides a new perspective for the study of the pathogenesis of liver cancer.

Short abstract

HuaChanSu suppresses expression of G6PD, the first rate-limiting enzyme of the PPP, restrains G6PD enzyme activity and dimer formation via inhibition of PLK1, knockdown of G6PD could impair the growth of human hepatoma cells and increase the blocking effect of HuaChanSu on cell proliferation of cancer cells. In addition, HuaChanSu restrains NADPH production and nucleotide level, implying the suppression of PPP flux. Our study suggests that HuaChanSu interferes with PPP via G6PD inhibition to exert anti-hepatoma effects.

Global trends in bufalin application research for cancer from 2003 to 2022: A bibliometric and visualised analysis

Background

Bufalin, the main active ingredient of the traditional Chinese medicine huachansu, is used in the clinical treatment of colorectal cancer and has multiple effects, including the inhibition of migratory invasion, reversal of multi-drug resistance, induction of apoptosis and differentiation, and inhibition of angiogenesis.

Methods

We collected relevant articles on bufalin from 2003 to 2022 using the Web Science platform, and analysed the information using VOSviewer, CiteSpace, and Microsoft Excel to categorise and summarise the publications over the past 20 years.

Results

We collected 371 papers, with a steady increase in the number of articles published globally. China has the highest number of published articles, whereas Japan has the highest number of citations. Currently, there is considerable enthusiasm for investigating the anti-tumour mechanism of bufalin and optimising drug delivery systems for its administration.

Conclusion

For the first time, we present a comprehensive overview of papers published worldwide on bufalin over the past two decades and the progress of its application in tumour therapy. We summarised the key authors, institutions, and countries that have contributed to the field and the potential of bufalin for the treatment of cancer. This will help other researchers obtain an overview of progress in the field, enhance collaboration and knowledge sharing, and promote future research on bufalin.

Efficacy and Safety of Huachansu as an Adjuvant Therapy for Non-Small Cell Lung Cancer: An Overview of Systematic Reviews and Meta-Analyses

OBJECTIVE

The purpose of this overview is to assess systematic reviews (SRs)/ meta-analyses (MAs) of Huachansu (HCS) combination chemotherapy for treating non-small cell lung cancer (NSCLC) and provide summarized evidence for clinical decision making.

METHODS

From the creation of the database to JUNE 2023, 8 databases in English and Chinese were searched. SRs/MAs that met the inclusion and exclusion criteria were included. Two reviewers independently screened research, extracted data and assessed methodological quality, risk of bias, report quality and evidence quality by using relevant criteria from AMSTAR-2, ROBIS scale, PRISMA, and GRADE system.

RESULTS

The short-term effect, long-term effect, quality of life improvement, safety and pain relief effect in 8 included SRs/MAs were assessed in this overview according to quantitative synthesis. Results assessed by AMSTAR-2, PRISMA, and ROBIS were generally unsatisfactory, with the results of the AMSTAR-2 assessment showing that all of them were of low or critically low quality; the number of items in the included research that were fully reported (compliance was 100%) by the PRISMA checklist was only 50%, while there were 38.10% of the research reporting less than 60% completeness; the ROBIS assessment showed a small number of systems to be low risk of bias. In addition, 26 items were rated as moderate quality, while 50.94% of items were rated as low or critically low quality by GRADE.

CONCLUSION

HCS may be a promising adjuvant therapy for NSCLC. However, high-quality SRs/MAs and randomized control trials (RCTs) should be conducted to provide sufficient evidence so as to draw a definitive conclusion.

Transcriptome Profiling of Cardiac Glycoside Treatment Reveals EGR1 and Downstream Proteins of MAPK/ERK Signaling Pathway in Human Breast Cancer Cells

Cardiac glycosides (CGs) constitute a group of steroid-like compounds renowned for their effectiveness in treating cardiovascular ailments. In recent times, there has been growing recognition of their potential use as drug leads in cancer treatment. In our prior research, we identified three highly promising CG compounds, namely lanatoside C (LC), peruvoside (PS), and strophanthidin (STR), which exhibited significant antitumor effects in lung, liver, and breast cancer cell lines. In this study, we investigated the therapeutic response of these CGs, with a particular focus on the MCF-7 breast cancer cell line. We conducted transcriptomic profiling and further validated the gene and protein expression changes induced by treatment through qRT-PCR, immunoblotting, and immunocytochemical analysis. Additionally, we demonstrated the interactions between the ligands and target proteins using the molecular docking approach. The transcriptome analysis revealed a cluster of genes with potential therapeutic targets involved in cytotoxicity, immunomodulation, and tumor-suppressor pathways. Subsequently, we focused on cross-validating the ten most significantly expressed genes, EGR1, MAPK1, p53, CCNK, CASP9, BCL2L1, CDK7, CDK2, CDK2AP1, and CDKN1A, through qRT-PCR, and their by confirming the consistent expression pattern with RNA-Seq data. Notably, among the most variable genes, we identified EGR1, the downstream effector of the MAPK signaling pathway, which performs the regulatory function in cell proliferation, tumor invasion, and immune regulation. Furthermore, we substantiated the influence of CG compounds on translational processes, resulting in an alteration in protein expression upon treatment. An additional analysis of ligand-protein interactions provided further evidence of the robust binding affinity between LC, PS, and STR and their respective protein targets. These findings underscore the intense anticancer activity of the investigated CGs, shedding light on potential target genes and elucidating the probable mechanism of action of CGs in breast cancer.

Anti-cancer activity of Marsdenialongise A, a new C21 steroidal glycoside isolated from Marsdenia longipes W.T. Wang (Apocynaceae)

C21 steroidal glycosides are a group of natural compounds with biological activities such as anti-cancer, anti-microbial, and anti-viral properties. In this study, we isolated and determined the structure of a new C21 steroidal glycoside, named Marsdenialongise A from Marsdenia longipes W.T. Wang, using nuclear magnetic resonance spectroscopy and mass spectra data. Marsdenialongise A is a derivative of tenacigenin B and was isolated for the first time from a plant. The inhibitory effect of Marsdenialongise A on cancer cells was evaluated through MTT and cell migration assays, cell cycle, and apoptosis analyses. The results of the MTT assay showed that Marsdenialongise A reduces the cell viability of cancer cells, with the AGS cell line being more sensitive than other cell lines, with an IC50 value of 5.69 µM (for 48 h of treatment). Marsdenialongise A also exhibited an ability to prevent the migration of cancer cells in AGS cells. Further analysis using flow cytometry has revealed that Marsdenialongise A is capable of inducing cell cycle arrest and apoptosis. The overexpression of reactive oxygen species (ROS) production induced by Marsdenialongise A can be considered a cause that leads to the influence on the cell cycle and apoptosis of cancer cells. Thus, Marsdenialongise A can be considered a potential anti-cancer agent.

Bioactivation and reactivity research advances - 2022 year in review‡

With the 50th year mark since the launch of Drug Metabolism and Disposition journal, the field of drug metabolism and bioactivation has advanced exponentially in the past decades (Guengerich 2023).This has, in a major part, been due to the continued advances across the whole spectrum of applied technologies in hardware, software, machine learning (ML), and artificial intelligence (AI). LC-MS platforms continue to evolve to support key applications in the field, and automation is also improving the accuracy, precision, and throughput of these supporting assays. In addition, sample generation and processing is being aided by increased diversity and quality of reagents and bio-matrices so that what is being analyzed is more relevant and translatable. The application of in silico platforms (applied software, ML, and AI) is also making great strides, and in tandem with the more traditional approaches mentioned previously, is significantly advancing our understanding of bioactivation pathways and how these play a role in toxicity. All of this continues to allow the area of bioactivation to evolve in parallel with associated fields to help bring novel or improved medicines to patients with urgent or unmet needs.Shuai Wang and Cyrus Khojasteh, on behalf of the authors.

Cell membrane-camouflaged bufalin targets NOD2 and overcomes multidrug resistance in pancreatic cancer

AIMS

Multidrug resistance in pancreatic cancer poses a significant challenge in clinical treatment. Bufalin (BA), a compound found in secretions from the glands of toads, may help overcome this problem. However, severe cardiotoxicity thus far has hindered its clinical application. Hence, the present study aimed to develop a cell membrane-camouflaged and BA-loaded polylactic-co-glycolic acid nanoparticle (CBAP) and assess its potential to counter chemoresistance in pancreatic cancer.

METHODS

The toxicity of CBAP was evaluated by electrocardiogram, body weight, distress score, and nesting behavior of mice. In addition, the anticarcinoma activity and underlying mechanism were investigated both in vitro and in vivo.

RESULTS

CBAP significantly mitigated BA-mediated acute cardiotoxicity and enhanced the sensitivity of pancreatic cancer to several clinical drugs, such as gemcitabine, 5-fluorouracil, and FOLFIRINOX. Mechanistically, CBAP directly bound to nucleotide-binding and oligomerization domain containing protein 2 (NOD2) and inhibited the expression of nuclear factor kappa-light-chain-enhancer of activated B cells. This inhibits the expression of ATP-binding cassette transporters, which are responsible for chemoresistance in cancer cells.

CONCLUSIONS

Our findings indicate that CBAP directly inhibits NOD2. Combining CBAP with standard-of-care chemotherapeutics represents a safe and efficient strategy for the treatment of pancreatic cancer.

Protective role of Dodonaea viscosa extract against streptozotocin-induced hepatotoxicity and nephrotoxicity in rats

Previous investigations have shown that D. viscosa herbal extract is often used to treat a variety of diseases. Therefore, the purpose of this study was to investigate any additional potential impacts on rat liver and kidney damage induced by diabetes. Streptozotocin (STZ) (60 mg/kg/day) was given as a single dosage to cause type 1 diabetes. After then, diabetic rats received oral doses of D. viscosa for four weeks at 150 and 300 mg/kg/day. Blood, liver, and kidney tissues were collected at the end of the treatment and examined. Analysis was made of the serum lipid profile, liver, and kidney functions, as well as blood biochemistry. Moreover, the levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), prostaglandin E-2 (PGE-2), and nitric oxide (NO) were estimated in serum. In liver and kidney samples, thiobarbituric acid reactive substances (TBARs) and reduced glutathione (GSH), as well as the pro-inflammatory cytokines and enzymatic activities of glutathione peroxidase (GPx), glutathione reeducates (GR), glutathione-S-transferase (GST), catalase (CAT), and superoxide dismutase (SOD) were analyzed. Histological changes in liver and kidney cross-sections were also observed. Our findings demonstrated that D. viscosa dramatically decreased pro-inflammatory indicators in blood, kidney, and liver tissues as well as blood glucose, and restored insulin levels, and lipid profiles. Additionally, it significantly raises the antioxidant enzyme activity SOD, CAT, GPx, and GST, while significantly lowering TBARs levels. The above-mentioned biochemical changes that took place in tissues were further supported by histological alterations. These findings imply that D. viscosa protects against STZ-induced hyperglycemia, aberrant lipid synthesis, and oxidative stress and that these benefits may be mediated by interacting with various targets to increase the levels of antioxidant enzymes in the liver and kidneys. Its mode of action and safety for use as medicine against various metabolic problems caused by diabetes require more research.

The Effects of Cinobufagin on Hepatocellular Carcinoma Cells Enhanced by MRT68921, an Autophagy Inhibitor

Cinobufagin, a cardiotonic steroid derived from toad venom extracts, exhibits significant anticancer properties by inhibiting Na[Formula: see text]/K[Formula: see text]-ATPase in cancer cells. It is frequently used in clinical settings to treat advanced-stage cancer patients, improving their quality of life and survival time. However, its long-term use can result in multidrug resistance to other chemotherapy drugs, and the exact mechanism underlying this effect remains unknown. Therefore, this study explores the molecular mechanism underlying the anticancer effects of cinobufagin in hepatocellular carcinomas (HCCs), specifically in HepG2 and Huh-7 cells. As determined using transcriptome analysis, cinobufagin-triggered protective autophagy suppressed cell apoptosis in liver cancer HepG2 and Huh-7 cells by inhibiting the phosphoinositide-3-Kinase (PI3K)-AKT serine/threonine kinase (AKT)-mammalian target of rapamycin (mTOR) pathway. Cinobufagin-inhibited cell proliferation, induced apoptosis, and generated cell autophagy by upregulating the expression of MAP1 light chain 3 protein II, Beclin1, and autophagy-related protein 12-5. In addition, the autophagy inhibitor MRT68921 improved the antiproliferative and proapoptotic effects of cinobufagin in the studied cell lines. Overall, this study suggests that combining cinobufagin with an autophagy inhibitor can effectively treat HCC, providing a potential strategy for cancer therapy.

Discovering Venom-Derived Drug Candidates Using Differential Gene Expression

Venoms are a diverse and complex group of natural toxins that have been adapted to treat many types of human disease, but rigorous computational approaches for discovering new therapeutic activities are scarce. We have designed and validated a new platform-named VenomSeq-to systematically identify putative associations between venoms and drugs/diseases via high-throughput transcriptomics and perturbational differential gene expression analysis. In this study, we describe the architecture of VenomSeq and its evaluation using the crude venoms from 25 diverse animal species and 9 purified teretoxin peptides. By integrating comparisons to public repositories of differential expression, associations between regulatory networks and disease, and existing knowledge of venom activity, we provide a number of new therapeutic hypotheses linking venoms to human diseases supported by multiple layers of preliminary evidence.

A Cross-Talk about Radioresistance in Lung Cancer-How to Improve Radiosensitivity According to Chinese Medicine and Medicaments That Commonly Occur in Pharmacies

Lung cancer is one of the most common cancers in the population and is characterized by non-specific symptoms that delay the diagnosis and reduce the effectiveness of oncological treatment. Due to the difficult placement of the tumor, one of the main methods of lung cancer treatment is radiotherapy, which damages the DNA of cancer cells, inducing their apoptosis. However, resistance to ionizing radiation may develop during radiotherapy cycles, leading to an increase in the number of DNA points of control that protect cells from apoptosis. Cancer stem cells are essential for radioresistance, and due to their ability to undergo epithelial-mesenchymal transition, they modify the phenotype, bypassing the genotoxic effect of radiotherapy. It is therefore necessary to search for new methods that could improve the cytotoxic effect of cells through new mechanisms of action. Chinese medicine, with several thousand years of tradition, offers a wide range of possibilities in the search for compounds that could be used in conventional medicine. This review introduces the potential candidates that may present a radiosensitizing effect on lung cancer cells, breaking their radioresistance. Additionally, it includes candidates taken from conventional medicine-drugs commonly available in pharmacies, which may also be significant candidates.

Unresectable hepatocellular carcinoma: transarterial chemoembolisation plus Huachansu - a single-center randomised controlled trial

OBJECTIVE

Huachansu, a Chinese medicine derived from the dried skin glands of toad venom, has been used in China since the 1970s to treat liver cancer. Transarterial chemoembolisation (TACE) is the standard of care for patients with unresectable hepatocellular carcinoma (HCC). This study evaluated the efficacy and safety of the combination of TACE and Huachansu in unresectable HCC.

METHODS

From September 2012 to September 2016, 120 patients diagnosed with unresectable HCC were prospectively enrolled. Patients were randomised at a 1:1 ratio into the combined treatment group (Huachansu-TACE) and the TACE treatment group. The primary endpoint was progression-free survival (PFS) and secondary endpoints were overall survival (OS) and safety. The exploration outcome serum Na⁺/K⁺-ATPase (NKA) α3 at baseline and 3-month follow-ups were compared for a prognostic role. All patients were subjected to 36-month follow-up.

RESULTS

A total of 112 patients who completed the study were included in the analysis. PFS and OS were significantly better in the Huachansu-TACE group than in the TACE group (p=0.029 and p=0.025, respectively), with a median PFS of 6.8 and 5.3; and a median OS of 14.8 months and 10.7 months, respectively. Although no prognostic significance was found between the baseline NKA-low and NKA-high groups in the patients' OS (p=0.48), its changes after 3-month follow-up showed significant prognostic values, of which, were 8.5 months and 23.8 months, respectively (p<0.001). Treatment-related adverse events were comparable between groups.

CONCLUSIONS

Huachansu-TACE is effective in prolonging the PFS and OS in patients with unresectable HCC.

TRIAL REGISTRATION NUMBER

NCT01715532.

Molecular and metabolic mechanisms of bufalin against lung adenocarcinoma: New and comprehensive evidences from network pharmacology, metabolomics and molecular biology experiment

BACKGROUND

This study aims to evaluate the efficacy and therapeutic mechanism of bufalin on lung adenocarcinoma (LUAD) through a comprehensive strategy integrating network pharmacology, metabolomics and molecular biology verification.

METHODS

The putative targets of bufalin were discerned from PharmMapper and Swiss Target Prediction database. LUAD-related targets were obtained by target filtering of GeneCard database and data mining of GEO database. PPI network was constructed to screen the core targets, and their clinical significance was assessed through several public databases. GO and KEGG pathway analyses were performed to identify possible enrichment of genes with specific biological themes. Molecular docking and molecular dynamics (MD) simulation were employed to determine the correlation and binding pattern between bufalin and core targets. The potential mechanisms of bufalin acting on LUAD, as predicted by network pharmacology analyses, were experimentally validated using in-vitro and in-vivo models. Finally, the effects of bufalin intervention on metabolite profile and metabolic pathway in LUAD nude mice were investigated by non-targeted metabolomics.

RESULTS

209 bufalin targets and 1082 LUAD-associated targets were harvested, of which 51 intersection targets were identified. 10 core targets including Akt1, STAT3, EGFR, CASP3 and SRC were picked out through network topology analysis, and they had a potent binding activity with bufalin as indicated by molecular docking and MD simulation. Hub module of PPI network was closely related to cell proliferation and apoptosis. GO and KEGG enrichment analyses suggested that bufalin exerted therapeutic effects on LUAD possibly by inhibiting proliferation and promoting apoptosis via PI3K/Akt, FoxO1 and MAPK/ERK pathways, which were confirmed by a series of in-vitro studies as well as HE, TUNEL and Ki-67 staining of tumor tissues. Further metabolomics analysis revealed that bufalin mainly regulated ABC transporter and remodeled AA metabolism, thereby contributing to the treatment of LUAD.

CONCLUSION

From molecular and metabolic perspective, the present study not only provided a unique insight into the possible mechanisms of bufalin against LUAD after successfully filtering out associated key target genes, differential endogenous metabolites, and signaling pathways, but also proposed a novel promising therapeutic strategy for LUAD.

Bufalin-Mediated Regulation of Cell Signaling Pathways in Different Cancers: Spotlight on JAK/STAT, Wnt/β-Catenin, mTOR, TRAIL/TRAIL-R, and Non-Coding RNAs

The renaissance of research into natural products has unequivocally and paradigmatically shifted our knowledge about the significant role of natural products in cancer chemoprevention. Bufalin is a pharmacologically active molecule isolated from the skin of the toad Bufo gargarizans or Bufo melanostictus. Bufalin has characteristically unique properties to regulate multiple molecular targets and can be used to harness multi-targeted therapeutic regimes against different cancers. There is burgeoning evidence related to functional roles of signaling cascades in carcinogenesis and metastasis. Bufalin has been reported to regulate pleiotropically a myriad of signal transduction cascades in various cancers. Importantly, bufalin mechanistically regulated JAK/STAT, Wnt/β-Catenin, mTOR, TRAIL/TRAIL-R, EGFR, and c-MET pathways. Furthermore, bufalin-mediated modulation of non-coding RNAs in different cancers has also started to gain tremendous momentum. Similarly, bufalin-mediated targeting of tumor microenvironments and tumor macrophages is an area of exciting research and we have only started to scratch the surface of the complicated nature of molecular oncology. Cell culture studies and animal models provide proof-of-concept for the impetus role of bufalin in the inhibition of carcinogenesis and metastasis. Bufalin-related clinical studies are insufficient and interdisciplinary researchers require detailed analysis of the existing knowledge gaps.

Bufalin reverses cancer-associated fibroblast-mediated colorectal cancer metastasis by inhibiting the STAT3 signaling pathway

At present, recurrence and metastasis are still important factors that lead to a poor prognosis among colorectal cancer (CRC) patients. Cancer-associated fibroblasts (CAFs) can promote tumorigenesis and development. Bufalin is the main active monomer of the clinical drug cinobufacini, which exhibits antitumor activity in various cancers. But few research have investigated the effect of bufalin in inhibiting metastasis from the perspective of the tumor microenvironment. We first isolated CAFs from freshly resected colorectal cancer patient specimens and observed the effect of CAFs on CRC cell invasion through a series of experiments. We explored the effect of bufalin on the physiological activity of CRC mediated by CAFs through experiments. In our study, we found that CAFs could promote CRC cell activity through the STAT3 pathway. Bufalin reversed CAF-mediated CRC invasion and metastasis by inhibiting the STAT3 pathway. Overexpression of STAT3 attenuated the inhibitory function of bufalin on invasion and metastasis. Taken together, bufalin can reverse CAF-mediated colorectal cancer metastasis based on inhibiting the STAT3 signaling pathway.

Drug Repurposing: A New Hope in Drug Discovery for Prostate Cancer

Prostate cancer (PCA), the most common cancer in men, accounted for 1.3 million new incidences in 2018. An increase in incidences is an issue of concern that should be addressed. Of all the reported prostate cancers, 85% were detected in stages III and IV, making them difficult to treat. Conventional drugs gradually lose their efficacy due to the developed resistance against them, thus requiring newer therapeutic agents to be used as monotherapy or combination. Recent research regarding treatment options has attained remarkable speed and development. Therefore, in this context, drug repurposing comes into the picture, which is defined as the "investigation of the off-patent, approved and marketed drugs for a novel therapeutic indication" which saves at least 30% of the time and cost, reducing the cost of treatment for patients, which usually runs high in cancer patients. The anticancer property of cardiac glycosides in cancers was tested in the early 1980s. The trend then shifts toward treating prostate cancer by repurposing other cardiovascular drugs. The current review mainly emphasizes the advantageous antiprostate cancer profile of conventional CVS drugs like cardiac glycosides, RAAS inhibitors, statins, heparin, and beta-blockers with underlying mechanisms.

Bufotalin ameliorates ovalbumin-induced allergic rhinitis by restoring the Tregs

BACKGROUND

Allergic rhinitis (AR) is one of the most common inflammatory diseases. IgE, inflammatory cytokine production and Th17/Tregs imbalance have been implicated in AR pathogenesis. Bufotalin, a component extracted from toad venom skin secretions and auricular glands, has anti-inflammatory activity and regulates Th17/Tregs balance. Here, the effects of bufotalin on AR were explored.

METHODS

The AR mice model was established using ovalbumin (OVA). AR mice were treated with bufotalin started on Day 22 with various doses (1, 10, 100 μg or 1 mg per mouse) every day to Day 30. The sneezing and rubbing frequencies were counted. Serum levels of IL-1β, IL-10 and OVA-specific IgE were measured. The superficial cervical lymph nodes were harvested and the percentage of Tregs in lymph node was determined using CD4 and Foxp3 markers.

RESULTS

OVA treatment successfully induced AR model in mice with significantly increased sneezing and rubbing frequency, elevated levels of serum histamine, IL-1β, IL-10 and OVA-specific IgE. Bufotalin treatment significantly ameliorated AR symptoms, with reduced histamine, IgE and IL-1β levels, as well as sneezing and rubbing frequency. Moreover, bufotalin treatment decreased the serum levels of IL-1β, IL-10 and OVA-specific IgE in AR mice.

CONLCUSION

Bufotalin ameliorated allergic rhinitis symptoms in AR mice by restoring Tregs in lymph node.

SRC-3 deficiency prevents atherosclerosis development by decreasing endothelial ICAM-1 expression to attenuate macrophage recruitment

Steroid receptor coactivator 3 (SRC-3) is a member of the p160 SRC family. This factor can interact with multiple nuclear hormone receptors and transcription factors to regulate the expression of their target genes. Although many physiological roles of SRC-3 have been revealed, its role in atherosclerosis is not clear. In this study, we found that SRC-3^-/-ApoE^-/- mice have reduced atherosclerotic lesions and necrotic areas in their aortas and aortic roots compared with SRC-3^+/+ApoE^-/- mice after Western diet (WD) feeding for 12 weeks. RNA-Seq and Western blot analyses of the aorta revealed that SRC-3 was required for maintaining the expression of ICAM-1, which was required for macrophage recruitment and atherosclerosis development. siRNA-mediated knockdown of SRC-3 in endothelial cells significantly reduced WD-induced atherosclerotic plaque formation. Additionally, treatment of ApoE^-/- mice with SRC-3 inhibitor bufalin prevented atherosclerotic plaque development. SRC-3 deficiency reduced aortic macrophage recruitment. Accordingly, ICAM-1 expression was markedly decreased in the aortas of SRC-3^-/-ApoE^-/- mice and ApoE^-/- mice with endothelial SRC-3 knockdown mediated by AAV9-shSRC-3 virus. Mechanistically, SRC-3 coactivated NF-κB p65 to increase ICAM-1 transcription in endothelial cells. Collectively, these findings demonstrate that inhibiting SRC-3 ameliorates atherosclerosis development, at least in part through suppressing endothelial activation by decreasing endothelial ICAM-1 expression via reducing NF-κB signaling.

Bufalin for an innovative therapeutic approach against cancer

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

Cinobufacini Injection Inhibits the Proliferation of Triple-Negative Breast Cancer Through the Pin1-TAZ Signaling Pathway

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer (BC), which is characterized by the total absence of human epidermal growth factor receptor 2 (HER2), progesterone receptor (PR), and estrogen receptor (ER) expression. Cinobufacini injection (CI) is the aqueous extract from the dry skin of Bufo gargarizans, which is broadly used for the treatment of malignant tumors. However, the potential mechanism of CI against TNBC has not been fully revealed. In this study, we found that CI inhibited the proliferation of MDA-MB-231 and 4T1 cells in a time- and dose-dependent manner. RNA-seq data showed that downregulated and upregulated genes were mainly enriched in biological processes related to tumor cell proliferation, including cell cycle arrest and regulation of apoptosis signaling pathways. Indeed, after CI treatment, the protein level of CDK1 and Bcl-2/Bax decreased, indicating that CI induced the cell cycle of MDA-MB-231 arrest in the G2/M phase and increased the rate of apoptosis. Meanwhile, CI significantly inhibited the growth of tumor in vivo, and RNA-seq data showed that the TAZ signaling pathway played a vital role after CI treatment. Both immunohistochemistry and Western blot analysis confirmed the downregulation of Pin1 and TAZ, caused by CI treatment. Furthermore, the bioinformatics analysis indicated that Pin1 and TAZ were indeed elevated in TNBC patients, with poor staging, classification, and patient survival rate. In conclusion, CI effectively inhibited the proliferation of TNBC in vitro and in vivo and induced their apoptosis and cycle arrest through the Pin1–TAZ pathway.

Synthesis and Biological Evaluation of Novel Bufalin Derivatives

Bufalin and other cardiac steroids (CS) have been used for centuries for the treatment of congestive heart failure, arrhythmias, and other maladies. However, toxicity and the small therapeutic window of this family of steroids limit their use. Therefore, attempts to synthesize a potent, but less toxic, CS are of major importance. In the present study, two novel bufalin derivatives were synthesized and some of their pharmacological properties were characterized. The reaction of bufalin with Ishikawa's reagent resulted in the production of two novel bufalin derivatives: bufalin 2,3-ene and bufalin 3,4-ene. The compounds were purified with TLC and HPLC and their structure was verified with UV, NMR, and MS analyses. The biological activities of these compounds were evaluated by testing their ability to inhibit the Na⁺, K⁺-ATPase activity of the brain microsomal fraction to induce cytotoxic activity against the NCI-60 human tumor cell line panel and non-cancer human cells, and to increase the force of contraction of quail embryonic heart muscle cells in culture. The two steroids exhibited biological activities similar to those of other CS in the tested experimental systems, but with reduced cytotoxicity, advocating their development as drugs for the treatment of heart failure and arrhythmias.

AHSA1 is a promising therapeutic target for cellular proliferation and proteasome inhibitor resistance in multiple myeloma

BACKGROUND

Currently, multiple myeloma (MM) is still an incurable plasma cell malignancy in urgent need of novel therapeutic targets and drugs.

METHODS

Bufalin was known as a highly toxic but effective anti-cancer compound. We used Bufalin as a probe to screen its potential targets by proteome microarray, in which AHSA1 was the unique target of Bufalin. The effects of AHSA1 on cellular proliferation and drug resistance were determined by MTT, western blot, flow cytometry, immunohistochemistry staining and xenograft model in vivo. The potential mechanisms of Bufalin and KU-177 in AHSA1/HSP90 were verified by co-immunoprecipitation, mass spectrometry, site mutation and microscale thermophoresis assay.

RESULTS

AHSA1 expression was increased in MM samples compared to normal controls, which was significantly associated with MM relapse and poor outcomes. Furthermore, AHSA1 promoted MM cell proliferation and proteasome inhibitor (PI) resistance in vitro and in vivo. Mechanism exploration indicated that AHSA1 acted as a co-chaperone of HSP90A to activate CDK6 and PSMD2, which were key regulators of MM proliferation and PI resistance respectively. Additionally, we identified AHSA1-K137 as the specific binding site of Bufalin on AHSA1, mutation of which decreased the interaction of AHSA1 with HSP90A and suppressed the function of AHSA1 on mediating CDK6 and PSMD2. Intriguingly, we discovered KU-177, an AHSA1 selective inhibitor, and found KU-177 targeting the same site as Bufalin. Bufalin and KU-177 treatments hampered the proliferation of flow MRD-positive cells in both primary MM and recurrent MM patient samples. Moreover, KU-177 abrogated the cellular proliferation and PI resistance induced by elevated AHSA1, and decreased the expression of CDK6 and PSMD2.

CONCLUSIONS

We demonstrate that AHSA1 may serve as a promising therapeutic target for cellular proliferation and proteasome inhibitor resistance in multiple myeloma.

Phylogeographic study of the Bufo gargarizans species complex, with emphasis on Northeast Asia

We conduct a phylogeographic and population genetic study of the Asiatic toad (Bufo gargarizans) to understand its evolutionary history, and the influence of geology and climate. A total of 292 individuals from 94 locations were genotyped for two mitochondrial loci (cytb, ND2) and five nuclear introns (Sox9-2, Rho-3, CCNB2-3, UCH-2, and DBI-2), and we performed a suite of phylogenetic, population genetic, and divergence dating analyses. The phylogenetic trees constructed using mitochondrial loci inferred B. gargarizans being divided into two major groups: China mainland and Northeast Asia (Northeast China, Russia, and Korean Peninsula). As with previous studies of this species, we recover population genetic structure not tied to geographic region. Additionally, we discover a new genetic clade restricted to Northeast Asia that points towards the Korean Peninsula being a glacial refugium during the Pleistocene. The weak phylogeographic pattern of B. gargarizans is likely the result of multiple biological, anthropogenic, and historical factors – robust dispersal abilities as a consequence of physiological adaptations, human translocation, geologic activity, and glacial cycles of the Pleistocene. We highlight the complex geologic and climatic history of Northeast Asia and encourage further research to understand its impact on the biodiversity in the region.

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.

Bufalin enhances the killing efficacy of NK cells against hepatocellular carcinoma by inhibiting MICA shedding

Bufalin, as a Chinese traditional anti-tumor agent, has been studied about inhibiting proliferation and promoting apoptosis of liver cancer, however, there are few reports on immune modulating function. We used the human liver cancer cell lines along with 91 pathologically-verified postoperative hepatocellular carcinoma (HCC) specimens to assess immune modulating function of bufalin. We found that bufalin directly balances stimulatory and inhibitory receptors on the surface of NK cells and indirectly activates natural killer (NK) cells by inhibiting MICA shedding, which prevented immune escape and indirectly enhanced NKG2D-dependent immune surveillance. This study showed that bufalin can directly or indirectly regulate the immune response, which provides a new theoretical basis for the clinical application of "Huachansu injection".

Clinical efficacy and safety of Huachansu injection combination with platinum-based chemotherapy for advanced non-small cell lung cancer: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Huachansu injection (HCS) is a widely used traditional Chinese medicine for advanced non-small cell lung cancer (NSCLC) to alleviate the adverse drug reactions (ADRs) and enhance the clinical efficacy of chemotherapy.

OBJECTIVE

To evaluate the efficacy and safety of HCS as an adjunctive treatment to platinum-based chemotherapy (PBC) for advanced NSCLC.

METHODS

A systematic review and meta-analysis were conducted according to PRISMA guidelines. A total of nine databases were searched to select randomized controlled trials (RCTs) of HCS plus PBC to treat NSCLC from inception to October 10, 2020. RCTs on HCS plus PBC vs PBC alone for advanced NSCLC were included. Dichotomous data were pooled as risk ratio (RR) with 95% confidence intervals. RCTs compared to HCS plus PBC vs PBC alone were included. Primary outcomes were objective response rate (ORR) and disease control rate (DCR), and secondary outcomes were survival rate, quality of life (QOL), and adverse drug reactions (ADRs). GRADE software was used to access the quality of evidence.

RESULTS

A total of 32 RCTs, including 2753 patients, were included. Compared to PBC alone, HCS plus PBC improved the ORR, DCR, 1- and 2-year survival rates, and QOL and alleviated neutropenia, thrombocytopenia, nausea, vomiting, anemia, liver injury, renal injury, and alopecia.

CONCLUSIONS

Compared to PBC alone, HCS plus PBC improved the clinical efficacy and alleviated the ADRs in advanced NSCLC patients. Considering the limitations of the included RCTs, high-quality trials with longer follow-ups are needed to further confirm the results.

Effects of low-dose bufalin combined with hydroxycamptothecin on human castration-resistant prostate cancer xenografts in nude mice

Prostate cancer is the most prevalent tumor found in men worldwide. Despite the efficiency of primary endocrine prostate cancer therapies, more efficient drugs are needed to tackle the most advanced and resistant forms of this condition. The present study investigated the antitumor effects of low-dose bufalin combined with hydroxycamptothecin on castration-resistant prostate cancer (CRPC) in mice, as well as the possible mechanisms of apoptosis induction. CRPC xenograft tumors were generated in mice and, subsequently, mice received appropriate doses of bufalin, hydroxycamptothecin or a combination of the two drugs. Tumors from each treatment group were removed, and the tumor volume, weight and inhibition rate of each group was determined. Hematoxylin and eosin staining was performed for pathological analysis and TUNEL staining was used to assess the level of apoptosis in the xenografts. Immunohistochemistry was used for the analysis of proliferating cell nuclear antigen expression and the expression of Bax, Bcl-XL, p53, programmed cell death 4 (PDCD4), phosphorylated (p)-AKT and glycogen synthase kinase (GSK)-3β was determined by western blotting. Treatment with bufalin significantly (P<0.05) reduced tumor volumes compared with the negative control group, reducing tumor volumes to lower levels when combined with hydroxycampothecin. The combination of bufalin (0.6 or 0.8 mg/kg) and hydroxycampothecin significantly (P<0.05) induced higher levels of cell apoptosis compared with the administration of bufalin or hydroxycampothecin alone. The combination of bufalin and hydroxycampothecin also increased the expression of apoptosis-related proteins Bax, p53, PDCD4 and GSK-3β, and decreased the expression of Bcl-XL and p-AKT compared with a single drug treatment. The present study suggested that the combination of bufalin and hydroxycampothecin improved the inhibitory effects of both drugs on CRPC tumors in vivo, potentially via the regulation of the PI3K/AKT/GSK-3β and p53-dependent apoptosis signaling pathways.

Bufalin inhibits peritoneal dissemination of gastric cancer through endothelial nitric oxide synthase-mitogen-activated protein kinases signaling pathway

Peritoneal dissemination threatens the survival of patients with gastric cancer (GC). Bufalin is an extract of traditional Chinese medicine, which has been proved to have anticancer effect. The target of bufalin in suppressing gastric cancer peritoneal dissemination (GCPD) and the underlying mechanism are still unclear. In this research, GC cell line MGC-803 and high-potential peritoneal dissemination cell line MKN-45P were treated with bufalin or L-NAME. Malignant biological behavior and protein level of GC cell lines were detected with MTT, wound healing, transwell, adhesion, and western blotting. Bioinformatics analysis and patient tissues were used to verify the role of endothelial nitric oxide synthase (NOS3) in GC. Mice model was used to assess the effect of bufalin and role of NOS3 in vivo. We found that bufalin inhibited the proliferation, invasion, and migration in GC cell lines. NOS3, which was an independent prognostic factor of GC patients, was predicted to be a potential target of bufalin. Further experiments proved that bufalin reduced the phosphorylation of NOS3, thereby inhibiting the mitogen-activated protein kinase (MAPK) signaling pathway, and ultimately suppressed GCPD by inhibiting EMT process. In conclusion, NOS3 was a potential therapeutic target and prognostic biomarker of GC. Bufalin could suppress GCPD through NOS3-MAPK signaling pathway, which provided more evidence support for intraperitoneal perfusion of bufalin to treat GCPD.

Bufalin inhibits human diffuse large B-cell lymphoma tumorigenesis by inducing cell death through the Ca2+/NFATC1/cMYC pathway

The 5-year survival rate of diffuse large B-cell lymphoma (DLBCL) can reach 60%. However, nearly half of patients undergo relapse/refractory issues with a survival period of less than 2 years. New therapeutic approaches are therefore needed to improve chemotherapy efficacy and patient survival. Bufalin (BF), isolated from the traditional Chinese medicine Chansu, has been reported to play an anticancer role in multiple cancer cell types. However, there are few reports of the effects of BF on the growth of DLBCL. In the present study, we demonstrated that BF exerts antitumor activity in DLBCL cells, both in vitro and in vivo. Treatment of DLBCL cells with BF resulted in increased proliferation and apoptosis in a dose- and time-dependent manner. Daily intraperitoneal injection of 1.5 mg/kg BF significantly delayed DLBCL xenograft growth in NOD/SCID mice without affecting body weight. Bioinformatics analysis showed that BF may regulate NFATC1 protein and affect expression of its downstream gene, cMYC. Our results suggest that BF can attenuate NFATC1 translocation by reducing the intracellular calcium concentration; BF may also have a low synergistic effect with cyclosporin A. In conclusion, we demonstrated that BF exerts antitumor activity that is mediated at least in part by the Ca2+/NFATC1/cMYC pathway. Our findings suggest that BF can be effectively applied as a novel potential therapeutic agent for DLBCL.

Potential anticancer activity of Acetone extracts of Toona cilliata, Seriphium plumosum and Schkuhria pinnata on HeLa cervical cancer cells

Background

Cervical cancer is common in women in less developed regions of the world. The plant biomolecules can be employed for synergistic activity with chemo- and radiotherapy. This combinations might result in reduced toxicity and increased efficacy of the treatment regimen.

Objectives

The anti-HeLa cells activity of the acetone extracts of S. plumosum, T. cilliata and S. pinnata was assessed using different parameters.

Methods

Secondary metabolite detection and antioxidant activity quantification were determined using the DPPH and ferric iron reducing assays. HeLa cell growth inhibition and mechanistics were assessed by employing MTT and Annexin-V flous assays.

Results

Observations revealed the presence of phenolic, flavonoids, tannins steroids and coumarins in all the plants extracts. High amount of total phenolic and flavonoid content were detected in S. plumosum and T. cilliata. S. plumosum extract had the best DPPH scavenging activity and ferric reducing powers.

Conclusion

Observable concentration dependent cell proliferation inhibition by test materials was exhibited. The leaf extracts from T. cilliata, S. plumosum and S. pinnata contain compounds of various polarities with free-radical, antioxidant and anti-cancerous activities that may play a beneficial role in treatment.

Surfactant Assisted Rapid-Release Liposomal Strategies Enhance the Antitumor Efficiency of Bufalin Derivative and Reduce Cardiotoxicity

Background

BF211, a derivative of bufalin (BF), shows significantly improved solubility and potent antitumor efficiency compared to BF. Unfortunately, the unwanted toxicity such as cardiotoxicity caused by unspecific distribution has hindered its clinical use.

Methods

PEGylated BF211 liposomes (BF211@Lipo) were designed and optimizely prepared based on the pre-prescription research. In vitro and in vivo cardiotoxicity was evaluated. In vivo pharmacokinetics and biodistribution of BF211@Lipo were investigated. In vivo antitumor activity and toxicity were evaluated in HepG2 cell xenograft models. The rapid-release triggered by Poloxamer 188 (P188) was assessed in vitro and in vivo.

Results

The optimized BF211@Lipo displayed a spherical morphology with a size of (164.6 ± 10.3) nm and a high encapsulation efficiency of (93.24 ± 2.15) %. The in vivo concentration–time curves of BF211 loaded in liposomes showed a prolonged half-life in plasma and increased tumor accumulation. No obvious abnormality in electrocardiograms was observed in guinea pigs even at 9 mg/kg. Moreover, to improve the efficient release of BF211@Lipo, a surfactant-assisted rapid-release strategy was developed, and the release-promoting mechanism was revealed by the fluorescence resonance energy transfer (FRET) and fluorescence nanoparticle tracking analysis (fl-NTA) technology. Sequential injection of BF211@Lipo and P188 could ignite the “cold” liposomes locally in tumor regions, facilitating the burst release of BF211 and enhancing the therapeutic index.

Conclusion

Our progressive efforts that begin with preparation technology and dosage regimen enable BF211 to like a drug, providing a promising nano platform to deliver the cardiac glycosides and alleviate the side effects by decreasing unspecific biodistribution.

Bufalin targets the SRC-3/MIF pathway in chemoresistant cells to regulate M2 macrophage polarization in colorectal cancer

M2-polarized macrophages are one of critical factors in tumour chemoresistance. An increasing number of studies have shown that M2 macrophage polarization can be promoted by chemoresistance. A large number of evidences indicate that Bufalin has significant antitumour effect, previous studies have found that Bufalin can reduce the polarization of M2 macrophages to play an anti-tumour effect in vivo, but the mechanism remains unclear. In our study, we found that Bufalin reduced the polarization of M2 macrophages induced by chemoresistant cells both in vivo and in vitro; however, Bufalin had no obvious direct effect on M2 macrophage polarization. Furthermore, we demonstrated that Bufalin targeted the SRC-3 protein to reduce MIF release in chemoresistant cells in order to regulate the polarization of M2 macrophages. More interestingly, we also found that Cinobufacini, Bufalin is its main active monomer, which its could regulate the polarization of M2 macrophages to enhance the anti-tumour effect of oxaliplatin in vivo and in the clinic. Overall, this study provides a theoretical basis for the clinical application of drugs containing Bufalin as the main active ingredient in combination with established chemotherapy for the treatment of colorectal cancer.

The Effectiveness and Safety of Cinobufotalin Injection as an Adjunctive Treatment for Lung Cancer: A Meta-Analysis of Randomized Controlled Trials

Cinobufotalin injection is a water-soluble preparation extracted from the skin secretion of Bufo bufo gargarizans Cantor or B. melanotictus Schneider, which has been widely used as an adjuvant treatment in lung cancer patients. This study aimed to evaluate the clinical efficacy and safety of cinobufotalin (PubChem CID: 259776) injection as an adjunctive treatment for lung cancer. We designed a meta-analysis that performed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We aim to include randomized controlled trials by systematically searching the PubMed, EMBASE, CNKI, Wanfang database, VIP, CBM, the Cochrane Central Register of Controlled Trials, and Chinese Clinical Trial Registry from inception to Mar 1, 2020, comparing the difference between the use of cinobufotalin injection as an adjunctive treatment and a control group without cinobufotalin injection. The objective response rate (ORR) and quality of life (QOL) will be defined as the primary outcomes, and the disease control rate (DCR) and adverse events will be defined as the secondary outcomes. We included 21 articles with 1735 cases of lung cancer patients. Comparison results show that combining with cinobufotalin injection can improve ORR (OR = 1.77, 95% CI [1.43, 2.21], P < 0.001), with low heterogeneity (P = 0.94, I ² = 0%); DCR (OR = 2.20, 95% CI [1.70, 2.85], P < 0.001), with low heterogeneity (P = 0.60, I ² = 0%); KPS score (OR = 3.10, 95% CI [2.23, 4.32], P < 0.001), with low heterogeneity (P = 0.85, I ² = 0%); and the effect of pain relief (OR = 2.68, 95% CI [1.30, 5.55], P = 0.008), with low heterogeneity (P = 0.72, I ² = 0%). Low-to-moderate evidence shows that cinobufotalin injection combined with chemotherapy can significantly increase ORR, DCR, QOL, and the effect of pain relief. Meanwhile, cinobufotalin injection did not bring additional adverse events such as hematological toxicity, gastrointestinal toxicity, cardiotoxicity, hepatotoxicity, and nephrotoxicity; however, multicenter, large-sample, high-quality clinical research results are still needed to reveal the therapeutic effect of cinobufotalin injection in small-cell lung cancer (PROSPERO registration number: CRD42020170052).

Prospects and Therapeutic Applications of Cardiac Glycosides in Cancer Remediation

Active metabolites from natural sources are the predominant molecular targets in numerous biological studies owing to their appropriate compatibility with biological systems and desirable selective toxicities. Thus, their potential for therapeutic development could span a broad scope of disease areas, including pathological and neurological dysfunctions. Cardiac glycosides are a unique class of specialized metabolites that have been extensively applied as therapeutic agents for the treatment of numerous heart conditions, and more recently, they have also been explored as probable antitumor agents. They are a class of naturally derived compounds that bind to and inhibit Na⁺/K⁺-ATPase. This study presents cardiac glycosides and their analogues with highlights on their applications, challenges, and prospects as lead compounds for cancer treatment.

Unified Total Synthesis of Five Bufadienolides

We report a unified total synthesis of five bufadienolides: bufalin (1), bufogenin B (2), bufotalin (3), vulgarobufotoxin (4), and 3-(N-succinyl argininyl) bufotalin (5). After the steroidal ABCD ring 8 was produced, the D ring was cross-coupled with a 2-pyrone moiety and stereoselectively epoxidized to generate 6. TMSOTf promoted a stereospecific 1,2-hydride shift from 6 to establish the β-oriented 2-pyrone of 19. Functional group manipulations from 19 furnished 1-5, which potently inhibited cancer cell growth.

Antitumor Activity of the Cardiac Glycoside αlDiginoside by Modulating Mcl-1 in Human Oral Squamous Cell Carcinoma Cells

We recently isolated a cardiac glycoside (CG), αldiginoside, from an indigenous plant in Taiwan, which exhibits potent tumor-suppressive efficacy in oral squamous cell carcinoma (OSCC) cell lines (SCC2095 and SCC4, IC₅₀ < 0.2 µM; 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays). Here, we report that αldiginoside caused Sphase arrest and apoptosis, through the inhibition of a series of signaling pathways, including those mediated by cyclin E, phospho-CDC25C (p-CDC25C), and janus kinase/signal transducer and activator of transcription (JAK/STAT)3. αldiginoside induced apoptosis, as indicated by caspase activation and poly (ADP-ribose) polymerase (PARP) cleavage. Equally important, αldiginoside reduced Mcl-1 expression through protein degradation, and overexpression of Mcl-1 partially protected SCC2095 cells from αldiginoside’s cytotoxicity. Taken together, these data suggest the translational potential of αldiginoside to foster new therapeutic strategies for OSCC treatment.

Efficacy and Safety of Cinobufacin Combined with Chemotherapy for Advanced Breast Cancer: A Systematic Review and Meta-Analysis

Background

Cinobufacin is a Chinese patent medicine widely used for breast cancer in China. However, no systematic review and meta-analysis have been published to validate its effects in breast cancer treatment. We, therefore, summarize the efficacy and safety of Cinobufacin combined with chemotherapy in order to provide rigid evidence for its clinical application.

Methods

By searching multiple databases incepted to December 2019, the RCTs of breast cancer patients treated with Cinobufacin were screened according to the inclusion criteria, and the meta-analysis and sensitivity analysis were conducted using RevMan5.3.

Results

A total of 1163 articles were retrieved, and 16 studies were included. The total sample size was 1331 cases, including 666 cases in the treatment group receiving Cinobufacin combined with chemotherapy and 665 cases in the control group receiving chemotherapy alone. Our study found that the ORR (overall response rate) (RR = 1.35, 95% CI: [1.23, 1.49], P < 0.00001), CBR (clinical benefit rate) (RR = 1.14, 95% CI: [1.08, 1.21], P < 0.00001), KPS scores (RR = 1.98, 95% CI: [1.45, 2.68], P < 0.0001), and pain relief rate (RR = 1.34, 95% CI: [1.01, 1.78] P=0.04 of the Cinobufacin combined with chemotherapy group were better than those of the chemotherapy group, and the difference was statistically significant. Our study also discovered that the tumor markers (CA125, CA153, and CEA) in the Cinobufacin combined with chemotherapy group were lower than those in the chemotherapy group, which heterogeneity was derived from the low-quality literature included in the study, but the results were robust. In addition, in terms of safety, we found that the incidences of gastrointestinal reactions (RR = 0.58, 95% CI: [0.48, 0.70], P < 0.00001), liver and kidney damage (RR = 0.57, 95% CI: [0.38, 0.84], P=0.004), and hair loss (RR = 0.61, 95% CI: [0.40, 0.92], P=0.02) in the Cinobufacin combined chemotherapy group were lower than those in the chemotherapy group, and the difference was statistically significant, but the incidences of peripheral neurotoxicity (RR = 0.69, 95% CI: [0.26, 1.85], P=0.46) and myelosuppression (RR = 0.78, 95% CI: [0.46, 1.34], P=0.37) in the combined group were similar to those of the chemotherapy group, and the difference was not statistically significant.

Conclusions

Cinobufacin combined with chemotherapy can improve the clinical efficacy of breast cancer patients, enhance the quality of life of the patients, reduce the value of tumor markers such as CA125, CA153, and CEA, and lower the occurrence of adverse reactions such as gastrointestinal reactions, liver and kidney damage, and hair loss.

Identification of Antitumor Constituents in Toad Venom by Spectrum-Effect Relationship Analysis and Investigation on Its Pharmacologic Mechanism

(1) Background: Toad venom (Bufonis Venenum, known as ‘Chansu’ in Chinese), the secretion of the ear-side gland and skin gland of Bufo gargarizans cantor or Duttaphrynus melanostictus Schneider, has been utilized to treat several diseases in China for thousands of years. However, due to the chemical variability of the components, systematic chemical composition and the key pharmacophores in toad venom have not yet fully understood. Besides, it contains a variety of effective compounds with different physiological activity and chemotypes, mainly including alkaloids, bufogenins, bufotoxins, and so on. The recent pharmacological researches have demonstrated that several bufogenins have remarkable pharmacological effects, such as anti-inflammatory, analgesic effects, and anti-tumor effects. Aim of the study: To identify the bioactive compounds and pharmacophores originating from toad venom based on analyzing spectrum-effect relationship by chemometrics and to explore the anti-cancer mechanism primarily. (2) Materials and methods: Fingerprint of the 21 batches of samples was established using HPLC (High Performance Liquid Chromatography). The anti-tumor activity of extracts were determined by in-vitro assays. Chemometric analysis was used to establish the spectrum-effect model and screen for active ingredients. Pharmacodynamic tests for the screened active compound monomers were conducted with in-vitro assays. Further anti-tumor mechanisms were investigated using western blot and flow cytometry. (3) Results: The established spectrum-effect model has satisfactory fitting effect and predicting accuracy. The inhibitory effect of major screened compounds on lung carcinoma cells A549 were validated in vitro, demonstrating that arenobufagin, telocinobufogenin, and cinobufotalin had significant anti-tumor effects. Through further investigation of the mechanism by western blotting and flow cytometry, we elucidated that arenobufagin induces apoptosis in A549 cells with the enhanced expression of cleaved PARP (poly (ADP-ribose) polymerase). These results may provide valuable information for further structural modification of bufadienolides to treat lung cancer and a method for discovery of anti-tumor active compounds. Conclusions: Our research offers a more scientific method for screening the principal ingredients dominating the pharmacodynamic function. These screened compounds (arenobufagin, etc.) were proven to induce apoptosis by overactivation of the PARP-pathway, which may be utilized to make BRCA (breast cancer susceptibility gene) mutant cancer cells more vulnerable to DNA damaging agents and kill them.

Bufalin attenuates triple-negative breast cancer cell stemness by inhibiting the expression of SOX2/OCT4

Triple-negative breast cancer (TNBC) has the poorest prognosis among all types of breast cancer and there is yet no effective therapy. Chemotherapy is the traditional standard of care for patients with TNBC; however, treatment of TNBC with chemotherapy may lead to the enrichment of cancer stem cells (CSCs), which exhibitan enhanced capacity for self-renewal, tumor initiation and metastasis. The present study demonstrated that bufalin, a small molecular compound used in traditional Chinese medicine, exerted anticancer effects on a wide range of cancer cell lines, inhibited cell proliferation through inducing G2/M cell cycle arrest, and triggered apoptosis in the TNBC cell lines MDA-MB-231 and HCC-1937. Consistently, bufalin markedly suppressed TNBC growth in a cell line-derived xenograft model. More importantly, unlike common chemotherapeutic drugs, bufalin reduced the stemness of TNBC stem cells. A mechanistic study suggested that bufalin may suppress the proliferation of TNBC stem cells by inhibiting the expression of octamer-binding transcription factor 4 (OCT4) and sex determining region Y-box 2 (SOX2) in MDA-MB-231 and HCC-1937 cells. These results indicated that bufalin may hold promise as a therapeutic agent in TNBC, and its effects may be mediated through the SOX2/OCT4 axis.

Toad Venom Antiproliferative Activities on Metastatic Melanoma: Bio-Guided Fractionation and Screening of the Compounds of Two Different Venoms

Melanoma is the most common cancer in young adults, with a constantly increasing incidence. Metastatic melanoma is a very aggressive cancer with a 5-year survival rate of about 22-25%. This is, in most cases, due to a lack of therapies which are effective on the long term. Hence, it is crucial to find new therapeutic agents to increase patient survival. Toad venoms are a rich source of potentially pharmaceutically active compounds and studies have highlighted their possible effect on cancer cells. We focused on the venoms of two different toad species: Bufo bufo and Rhinella marina. We screened the venom crude extracts, the fractions from crude extracts and isolated biomolecules by studying their antiproliferative properties on melanoma cells aiming to determine the compound or the combination of compounds with the highest antiproliferative effect. Our results indicated strong antiproliferative capacities of toad venoms on melanoma cells. We found that these effects were mainly due to bufadienolides that are cardiotonic steroids potentially acting on the Na⁺/K⁺ ATPase pump which is overexpressed in melanoma. Finally, our results indicated that bufalin alone was the most interesting compound among the isolated bufadienolides because it had the highest antiproliferative activity on melanoma cells.