Cinobufagin Induces Cell Cycle Arrest at the G2/M Phase and Promotes Apoptosis in Malignant Melanoma Cells

Research progress of Chinese medicinal monomers in the process of melanoma occurrence

CONTEXT

Melanoma's aggressiveness and resistance to radiotherapy highlight an urgent need for innovative treatments. Traditional Chinese medicine (TCM) offers a unique approach through its 'four natures' theory-cold, cool, warm, and hot.

OBJECTIVE

This review aims to explore the potential of TCM's 'four natures' herbal monomers in melanoma treatment, providing an alternative to conventional therapies.

MATERIALS & METHODS

A systematic literature review was conducted by accessing various databases, including Baidu Scholar, PubMed, Science Citation Index Expanded (SCIE), and China National Knowledge Infrastructure (CNKI), to synthesize the most recent findings on traditional Chinese medicine monomers. Furthermore, this review elucidated the mechanisms underlying their role in melanoma retention.

RESULTS

TCM's multi-component, multi-target approach has shown promise in addressing melanoma's complexity, with specific monomers demonstrating the ability to modulate tumor behavior.

DISCUSSION AND CONCLUSIONS

The 'four natures' theory in TCM presents a novel perspective for melanoma treatment, warranting further investigation into its clinical applications and potential integration with modern oncology.

A Newly Synthesized Benzimidazolium Salt: 1-(2-Cyanobenzyl)-3-(4-Vinylbenzyl)-1H-Benzo[D]imidazol-3-ium Chloride as a Potential Anticancer Agent for Colon Cancer Treatment, In Vitro Study

Colon cancer is one of the most common cancer-related deaths. Drug resistance is one of the biggest challenges in cancer treatment. Numerous pharmacological and biochemical investigations have documented the benzimidazole ring's anticancer, anti-inflammatory, and antioxidant properties. Within the scope of our project, the effect of newly synthesized benzimidazolium salt (BS) on cell proliferation was tested with MTT assay, and its effect on apoptosis and cell cycle was tested with annexin V and PI in the two different colon cancer cell lines (HT-29 and DLD-1). Our study examined the expressions of some genes related to apoptosis and, additionally, caspase activities with the multicaspase kit. BS showed an antiproliferative effect at lower doses in HT-29 colon cancer cells. When HT-29 cells were exposed to a 20 µM dosage, they showed increased caspase activity and apoptosis compared to DLD-1 cells. HT-29 accumulated in the G2/M phase of the cell cycle, whereas DLD-1 cells accumulated more in the S phase. In HT-29 cells, colony formation was inhibited; however, in DLD-1 cells, this effect was insufficient. Based on the apoptosis-death pathway, BS is expected to have anti-cancer effects. As a result of this work, this chemical was thoroughly examined in two different colon cancer cell lines, and additional, more comprehensive initiatives are being planned in light of the information obtained from this study.

Unveiling the antitumor mechanism of 7α-acetoxy-6β-hydroxyroyleanone from Plectranthus hadiensis in glioblastoma

ETHNOPHARMACOLOGICAL RELEVANCE

Glioblastoma (GB) is the most aggressive and prevalent glioma within the central nervous system. Despite considerable efforts, GB continues to exhibit a dismal 5-year survival rate (∼6%). This is largely attributed to unfavorable prognosis and lack of viable treatment options. Therefore, novel therapies centered around plant-derived compounds emerge as a compelling avenue to enhance patient survival and well-being. The South African species, Plectranthus hadiensis Schweinf. (P. hadiensis), a member of the Lamiaceae family, has a history of use in traditional medicine for treating a range of diseases, including respiratory, digestive, and liver disorders. This species exhibits diverse biological activities, such as anti-inflammatory and antitumoral properties, likely attributed to its rich composition of naturally occurring diterpenes, like the abietane diterpene, 7α-acetoxy-6β-hydroxyroyleanone (Roy). Roy has demonstrated promising antitumor effects in various cancer cell lines, making it a compelling candidate for further investigation into its mechanisms against GB.

AIM OF THE STUDY

This study aims to investigate the antitumor activity and potential mechanism of Roy, a natural lead compound, in GB cells.

MATERIAL AND METHODS

Roy was isolated from the acetonic extract of P. hadiensis and its antitumor mechanism was assessed in a panel of human GB cell lines (U87, A172, H4, U373, and U118) to mimic tumor heterogeneity. Briefly, the impact of Roy treatment on the metabolic activity of cells was evaluated by Alamar Blue® assay, while cell death, cell cycle regulation, mitochondrial membrane potential, and activated caspase-3 activity were evaluated by flow cytometry. Measurement of mRNA levels of target genes was performed by qPCR, while protein expression was assessed by Western blotting. Cell uptake and impact on mitochondrial morphology were evaluated by confocal microscopy.

RESULTS

Roy induced G2/M cell cycle arrest, mitochondrial fragmentation, and apoptosis by inhibiting the expression of anti-apoptotic proteins and increasing the levels of activated caspase-3. The concentrations of Roy needed to achieve significant inhibitory outcomes were notably lower (6-9 fold) than those of temozolomide (TMZ), the standard first-line treatment, for achieving comparable effects. In addition, at low concentrations (16 μM), Roy affected the metabolic activity of tumor cells while having no significant impact on non-tumoral cells (microglia and astrocytes).

CONCLUSION

Overall, Roy demonstrated a robust antitumor activity against GB cells offering a promising avenue for the development of novel chemotherapeutic approaches.

Cytotoxic activity of silver nanoparticles prepared by eco-friendly synthesis using Lythrum salicaria extract on breast cancer cells

BACKGROUND

Metal nanoparticles (NPs) have widely been investigated due to their several applications in therapeutic activities. The current investigation highlights the cytotoxic effects of the eco-friendly phytosynthesis route for silver nanoparticles using Lythrum salicaria (L. salicaria) extract (AgNPs-LS).

METHODS AND RESULTS

The change in color from colorless to brown confirmed the reduction of silver ions to AgNPs. x-ray diffraction (XRD) analysis demonstrated high crystallinity. The surface morphology of AgNPs-LS was spherical, and their average sizes were 50 nm. energy-dispersive x-ray analysis (EDAX) confirmed that silver was the predominant component, indicating the involvement of L. salicaria plant extract in the green synthesis process. In vitro dimethyl thiazolyl tetrazolium bromide (MTT) assay showed significant cytotoxicity of AgNPs-LS against MCF7 cells, with an IC50 of 113 µg mL- 1. In contrast, AgNPs-LS showed minimal cytotoxicity to HEK293 cells (IC50: 254 µg mL- 1), demonstrating a higher sensitivity of cancer cells to AgNPs-LS. Moreover, AgNPs-LS resulted in MCF7 cells producing reactive oxygen species (ROS) and undergoing cell cycle arrest at the G2/M phase, serving as barriers to the proliferation of cancer cells. Annexin V fluorescein isothiocyanate (FITC) assays and fluorescence microscopy confirmed the induction of apoptosis in MCF7 cells by AgNPs-LS. Gene expression analysis revealed upregulated pro-apoptotic genes (Bax, p53, caspase-3, and caspase-9) and downregulated an anti-apoptotic gene (Bcl2) in michigan cancer foundation7 (MCF7) cells treated with AgNPs-LS.

CONCLUSION

These results indicate that AgNPs-LS induced apoptosis via the intrinsic pathway (mitochondrial-mediated mechanism) and involved p53-dependent regulation. The current study results implied that AgNPs-LS fabricated by a bio-green approach could be helpful to the future of nanomedicine.

Encapsulation of 4-oxo-N-(4-hydroxyphenyl) retinamide in human serum albumin nanoparticles promotes EZH2 degradation in preclinical neuroblastoma models

Neuroblastoma is the most prevalent and aggressive solid tumor that develops extracranially in children between the ages of 0-14 years, which accounts for 8-10% of all childhood malignancies and ∼15% of pediatric cancer-related mortality. The polycomb repressive complex 2 (PRC2) protein, EZH2, is overexpressed in neuroblastoma and mediates histone H3 methylation at lysine 27 (K27) positions through its methyl transferase activity and is a potential epigenetic silencer of many tumor suppressor genes in cancer. Phosphorylation of EZH2 decreases its stability and leads to proteasomal degradation. The 4-oxo-N-(4-hydroxyphenyl) retinamide (4O4HPR) promotes EZH2 degradation via activation of PKC-δ, but its limited solubility and physiological instability limit its application. In the current study, the encapsulation of 4O4HPR in Human Serum Albumin Nanoparticles (HSANPs) enhanced the solubility and physiological stability of the nanoformulation, leading to improved therapeutic efficacy through G2-M cell cycle arrest, depolarization of mitochondrial membrane potential, generation of reactive oxygen species and caspase 3 mediated apoptosis activation. The molecular mechanistic approach of 4O4HPR loaded HSANPs has activated caspase 3, which further cleaves PKC-δ into two fragments wherein the cleaved fragment of PKC-δ possesses the kinase activity that phosphorylates EZH2 and decreases the protein stability leading to its further ubiquitination in SH-SY5Y cells. Co-immunoprecipitation experiments revealed the direct interaction between PKC-δ and EZH2 phosphorylation, followed by ubiquitination. Moreover, 4O4HPR loaded HSANPs demonstrated improved in vivo biodistribution, greater dispersibility, and biocompatibility and exhibited enhanced protein instability and degradation of EZH2 in the neuroblastoma xenograft mouse model.

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.

Predictive DNA damage signaling for low‑dose ionizing radiation

Numerous studies have attempted to develop biological markers for the response to radiation for broad and straightforward application in the field of radiation. Based on a public database, the present study selected several molecules involved in the DNA damage repair response, cell cycle regulation and cytokine signaling as promising candidates for low‑dose radiation‑sensitive markers. The HuT 78 and IM‑9 cell lines were irradiated in a concentration‑dependent manner, and the expression of these molecules was analyzed using western blot analysis. Notably, the activation of ataxia telangiectasia mutated (ATM), checkpoint kinase 2 (CHK2), p53 and H2A histone family member X (H2AX) significantly increased in a concentration‑dependent manner, which was also observed in human peripheral blood mononuclear cells. To determine the radioprotective effects of cinobufagin, as an ATM and CHK2 activator, an in vivo model was employed using sub‑lethal and lethal doses in irradiated mice. Treatment with cinobufagin increased the number of bone marrow cells in sub‑lethal irradiated mice, and slightly elongated the survival of lethally irradiated mice, although the difference was not statistically significant. Therefore, KU60019, BML‑277, pifithrin‑α, and nutlin‑3a were evaluated for their ability to modulate radiation‑induced cell death. The use of BML‑277 led to a decrease in radiation‑induced p‑CHK2 and γH2AX levels and mitigated radiation‑induced apoptosis. On the whole, the present study provides a novel approach for developing drug candidates based on the profiling of biological radiation‑sensitive markers. These markers hold promise for predicting radiation exposure and assessing the associated human risk.

Cell division cyclin 25C knockdown inhibits hepatocellular carcinoma development by inducing endoplasmic reticulum stress

BACKGROUND

Cell division cyclin 25C (CDC25C) is a protein that plays a critical role in the cell cycle, specifically in the transition from the G2 phase to the M phase. Recent research has shown that CDC25C could be a potential therapeutic target for cancers, particularly for hepatocellular carcinoma (HCC). However, the specific regulatory mechanisms underlying the role of CDC25C in HCC tumorigenesis and development remain incompletely understood.

AIM

To explore the impact of CDC25C on cell proliferation and apoptosis, as well as its regulatory mechanisms in HCC development.

METHODS

Hepa1-6 and B16 cells were transduced with a lentiviral vector containing shRNA interference sequences (LV-CDC25C shRNA) to knock down CDC25C. Subsequently, a xenograft mouse model was established by subcutaneously injecting transduced Hepa1-6 cells into C57BL/6 mice to assess the effects of CDC25C knockdown on HCC development in vivo. Cell proliferation and migration were evaluated using a Cell Counting Kit-8 cell proliferation assays and wound healing assays, respectively. The expression of endoplasmic reticulum (ER) stress-related molecules (glucose-regulated protein 78, X-box binding protein-1, and C/EBP homologous protein) was measured in both cells and subcutaneous xenografts using quantitative real-time PCR (qRT-PCR) and western blotting. Additionally, apoptosis was investigated using flow cytometry, qRT-PCR, and western blotting.

RESULTS

CDC25C was stably suppressed in Hepa1-6 and B16 cells through LV-CDC25C shRNA transduction. A xenograft model with CDC25C knockdown was successfully established and that downregulation of CDC25C expression significantly inhibited HCC growth in mice. CDC25C knockdown not only inhibited cell proliferation and migration but also significantly increased the ER stress response, ultimately promoting ER stress-induced apoptosis in HCC cells.

CONCLUSION

The regulatory mechanism of CDC25C in HCC development may involve the activation of ER stress and the ER stress-induced apoptosis signaling pathway.

Synthesis of Bufadienolide Cinobufagin via Late-Stage Singlet Oxygen Oxidation/Rearrangement Approach

This manuscript describes a concise synthesis of cinobufagin, a natural steroid of the bufadienolide family, from readily available dehydroepiandrosterone (DHEA), as well as its α5-epimer derived from 3-epi-andosterone. This synthesis features expedient installation of the 17β-pyrone moiety with the 14β,15β-epoxide and the 16β-acetoxy group using a photochemical regioselective singlet oxygen [4 + 2] cycloaddition followed by CoTPP-promoted in situ endoperoxide rearrangement to provide a 14β,16β-bis-epoxide in 64% yield with a 1.6:1 d.r. This β,β-bis-epoxide intermediate was subsequently subjected to a regioselective scandium(III) trifluoromethanesulfonate catalyzed House-Meinwald rearrangement to establish the 17β-configuration. The synthesis of cinobufagin is achieved in 12 steps (LLS) and 7.6% overall yield, and we demonstrate that it could be used as a platform for the subsequent medicinal chemistry exploration of cinobufagin analogs such as cinobufagin 5α-epimer.

Regulation of Cell Cycle Progression through RB Phosphorylation by Nilotinib and AT-9283 in Human Melanoma A375P Cells

BCR-ABL tyrosine kinase inhibitors are commonly employed for the treatment of chronic myeloid leukemia, yet their impact on human malignant melanoma remains uncertain. In this study, we delved into the underlying mechanisms of specific BCR-ABL tyrosine kinase inhibitors (imatinib, nilotinib, ZM-306416, and AT-9283) in human melanoma A375P cells. We first evaluated the influence of these inhibitors on cell growth using cell proliferation and wound-healing assays. Subsequently, we scrutinized cell cycle regulation in drug-treated A375P cells using flow cytometry and Western blot assays. Notably, imatinib, nilotinib, ZM-306416, and AT-9283 significantly reduced cell proliferation and migration in A375P cells. In particular, nilotinib and AT-9283 impeded the G1/S transition of the cell cycle by down-regulating cell cycle-associated proteins, including cyclin E, cyclin A, and CDK2. Moreover, these inhibitors reduced RB phosphorylation, subsequently inhibiting E2F transcriptional activity. Consequently, the expression of the E2F target genes (CCNA2, CCNE1, POLA1, and TK-1) was markedly suppressed in nilotinib and AT9283-treated A375P cells. In summary, our findings suggest that BCR-ABL tyrosine kinase inhibitors may regulate the G1-to-S transition in human melanoma A375P cells by modulating the RB-E2F complex.

A network pharmacology- and transcriptomics-based investigation reveals an inhibitory role of β-sitosterol in glioma via the EGFR/MAPK signaling pathway

Glioma is characterized by rapid cell proliferation, aggressive invasion, altered apoptosis and a poor prognosis. β-Sitosterol, a kind of phytosterol, has been shown to possess anticancer activities. Our current study aims to investigate the effects of β-sitosterol on gliomas and reveal the underlying mechanisms. Our results show that β-sitosterol effectively inhibits the growth of U87 cells by inhibiting proliferation and inducing G2/M phase arrest and apoptosis. In addition, β-sitosterol inhibits migration by downregulating markers of epithelial-mesenchymal transition (EMT). Mechanistically, network pharmacology and transcriptomics approaches illustrate that the EGFR/MAPK signaling pathway may be responsible for the inhibitory effect of β-sitosterol on glioma. Afterward, the results show that β-sitosterol effectively suppresses the EGFR/MAPK signaling pathway. Moreover, β-sitosterol significantly inhibits tumor growth in a U87 xenograft nude mouse model. β-Sitosterol inhibits U87 cell proliferation and migration and induces apoptosis and cell cycle arrest in U87 cells by blocking the EGFR/MAPK signaling pathway. These results suggest that β-sitosterol may be a promising therapeutic agent for the treatment of glioma.

Mechanisms underlying the therapeutic effects of cinobufagin in treating melanoma based on network pharmacology, single-cell RNA sequencing data, molecular docking, and molecular dynamics simulation

Malignant melanoma is one of the most aggressive of cancers; if not treated early, it can metastasize rapidly. Therefore, drug therapy plays an important role in the treatment of melanoma. Cinobufagin, an active ingredient derived from Venenum bufonis, can inhibit the growth and development of melanoma. However, the mechanism underlying its therapeutic effects is unclear. The purpose of this study was to predict the potential targets of cinobufagin in melanoma. We gathered known and predicted targets for cinobufagin from four online databases. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were then performed. Gene expression data were downloaded from the GSE46517 dataset, and differential gene expression analysis and weighted gene correlation network analysis were performed to identify melanoma-related genes. Using input melanoma-related genes and drug targets in the STRING online database and applying molecular complex detection (MCODE) analysis, we identified key targets that may be the potential targets of cinobufagin in melanoma. Moreover, we assessed the distribution of the pharmacological targets of cinobufagin in melanoma key clusters using single-cell data from the GSE215120 dataset obtained from the Gene Expression Omnibus database. The crucial targets of cinobufagin in melanoma were identified from the intersection of key clusters with melanoma-related genes and drug targets. Receiver operating characteristic curve (ROC) analysis, survival analysis, molecular docking, and molecular dynamics simulation were performed to gain further insights. Our findings suggest that cinobufagin may affect melanoma by arresting the cell cycle by inhibiting three protein tyrosine/serine kinases (EGFR, ERBB2, and CDK2). However, our conclusions are not supported by relevant experimental data and require further study.

Cytotoxic effects of Chartergellus communis wasp venom peptide against melanoma cells

Cancer is a huge public health problem being one of the main causes of death globally. Specifically, melanoma is one of the most threatening cancer types due to the metastatic capacity, treatment resistance and mortality rates. It is evident the urgent need for research on new agents with pharmacological potential for cancer treatment, in order to develop new cancer therapeutic strategies and overcome drug resistance. The present work investigated the anti-tumoral potential of Chartergellus-CP1 peptide, isolated from Chartergellus communis wasp venom on human melanoma cell lines with different pigmentation degrees, namely the amelanotic cell line A375 and pigmented cell line MNT-1. Chartergellus-CP1 induced selective cytotoxicity to melanoma cell lines when compared to the lower induced cytotoxicity towards to nontumorigenic keratinocytes. Chartergellus-CP1 peptide induced apoptosis in both melanoma cell lines, cell cycle impairment in amelanotic A375 cells and intracellular ROS increase in pigmented MNT-1 cells. The amelanotic A375 cell line showed higher sensitivity to the peptide than the pigmented cell line MNT-1. From our knowledge, this is the first study reporting the cytotoxic effects of Chartergellus-CP1 on melanoma cells.

Baicalin functionalized PEI-heparin carbon dots as cancer theranostic agent

The worldwide prevalence of cancer and its significantly rising risks with age have garnered the attention of nanotechnology for prompt detection and effective therapy with minimal or no adverse effects. In the current study, heparin (HP) polymer derived heteroatom (N, S-) co-doped CDs were synthesized using hydrothermal synthesis method to efficiently deliver natural anticancer compound baicalin (BA). Heparin carbon dots (HCDs) were passivated with polyethylenimine (PEI) to improve its fluorescence quantum yield. The surface passivation of CDs by polycationic PEI polymer not only facilitated loading of BA, but also played a crucial role in the pH-responsive drug delivery. The sustained release of BA (up to 80 %) in mildly acidic pH (5.5 and 6.5) conditions endorsed its drug delivery potential for cancer-specific microenvironments. BA-loaded PHCDs exhibited enhanced anticancer activity as compared to BA/PHCDs indicating the effectiveness of the nanoformulation, Furthermore, the flow cytometry analysis confirmed that BA-PHCDs treated cells were arrested in the G2/M phase of cell cycle and had a higher potential for apoptosis. Bioimaging study demonstrated the excellent cell penetration efficiency of PHCDs with complete cytoplasmic localization. All this evidence comprehensively demonstrates the potency of BA-loaded PHCDs as a nanotheranostic agent for cancer.

Gut Metabolite Indoxyl Sulfate Has Selective Deleterious and Anticancer Effect on Colon Cancer Cells

There are a number of reports about anticancer activity of indole derivatives. In this study, we investigated the role of indoxyl sulfate (IS) for its selective anticancer activity on colon cancer cells. IS treatment on HCT-116 and HT-29 human epithelial adenocarcinoma cells led to a decrease in cell proliferation, cell viability, and ATP content. Colon cancer cells showed a 10% increase in cell apoptosis in comparison to control. Due to IS treatment, cell morphology got distorted, cell number found decreased, intracellular vesicles formed, and cells were found floating in the media. Cells also showed a loss in membrane integrity and a decrease in colony-forming ability and ceased at the G2/M phase of the cell cycle. No significant change was noted in the level of inflammatory cytokines IL-17A, IL-1β, and TNF-α, histology, length of intestine, and spleen after 100 mM IS treatment to balb/c mice. These observations indicate the selective anticancer effect of IS on colon cancer cells.

Tumor suppressor Parkin induces p53-mediated cell cycle arrest in human lung and colorectal cancer cells

Dysregulation of the E3 ubiquitin ligase Parkin has been linked to various human cancers, indicating that Parkin is a tumor suppressor protein. However, the mechanisms of action of Parkin remain unclear to date. Thus, we aimed to elucidate the mechanisms of action of Parkin as a tumor suppressor in human lung and colorectal cancer cells. Results showed that Parkin overexpression reduced the viability of A549 human lung cancer cells by inducing G2/M cell cycle arrest. In addition, Parkin caused DNA damage and ATM (Ataxia telangiectasia mutated) activation, which subsequently led to p53 activation. It also induced the p53-mediated upregulation of p21 and downregulation of cyclin B1. Moreover, Parkin suppressed the proliferation of HCT-15 human colorectal cancer cells by a mechanism similar to that in A549 lung cancer cells. Taken together, our results suggest that the tumor-suppressive effects of Parkin on lung and colorectal cancer cells are mediated by DNA damage/p53 activation/cyclin B1 reduction/cell cycle arrest. [BMB Reports 2023; 56(10): 557-562].

Effect of differential deprivation of nutrients on cellular proliferation, oxidative stress, mitochondrial function, and cell migration in MDA-MB-231, HepG2, and HeLa cells

Cancerous cells display metabolic engineering through enhanced utilization of nutrients to support their increased requirements for proliferation, bioenergetics, biosynthesis, redox homeostasis, and cell signaling. To investigate the extent to which malignant cells rely on glycolysis and glutaminolysis, the effects of differential deprivation of nutrients such as d-glucose, l-glutamine, and pyruvate on proliferation, morphology, cell cycle, oxidative stress, mitochondrial function, autophagic vacuole formation, and migration in MDA-MB-231, HepG2, and HeLa cells were investigated in this study. Cell viability assay,  cell morphology, and ATP assay showed higher dependence of MDA-MB-231 and HepG2 cells on glucose and glutamine, respectively, for cell survival, growth, ATP production, and proliferation, while HeLa cells were equally dependent on both. However, the combination of all three nutrients displayed maximum proliferation. Differential deprivation of glucose in the absence of glutamine resulted in G0/G1 plus G2/M arrest in MDA-MB-231, whereas G0/G1 arrest in HepG2 and S-phase arrest in HeLa cells occurred at 48 h. Although the differential withdrawal of nutrients revealed a varying degree of effect dependent on cell type, nutrient type, nutrient concentrations, and deprivation time, a general trend of increased oxidative stress, loss of mitochondrial membrane potential, and ATP and antioxidant (GSH) depletion led to mitochondrial dysfunction in all three cell lines and inhibition of cell migration in MDA-MB-231 and HeLa cells at 48 h. Extreme deprivation of nutrients formed autophagic vacuoles. Importantly, normal cells (HEK293) remained unaffected under most of the nutrient-deprived conditions examined. This study enhances our understanding of the impact of differential nutrient deprivation on critical characteristics of cancer cells, contributing to the development of metabolism-based effective anticancer strategies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03759-w.

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.

Ultrasound-Activatable g-C3 N4 -Anchored Titania Heterojunction as an Intracellular Redox Homeostasis Perturbator for Augmented Oncotherapy

Energy band structure of inorganic nano-sonosensitizers is usually optimized by surface decoration with noble metals or metal oxide semiconductors, aiming to enhance interfacial charge transfer, augment spin-flip and promote radical generation. To avoid potential biohazards of metallic elements, herein, metal-free graphitic carbon nitride quantum dots (g-C₃ N₄ QDs) are anchored onto hollow mesoporous TiO₂ nanostructure to formulate TiO₂ @g-C₃ N₄ heterojunction. The direct Z-scheme charge transfer significantly improves the separation/recombination dynamics of electron/hole (e^- /h⁺ ) pairs upon ultrasound (US) stimulation, which promotes the yield of singlet oxygen (¹ O₂ ) and hydroxyl radicals (·OH). The conjugated g-C₃ N₄ QDs with peroxidase-mimic activity further react with the elevated endogenous H₂ O₂ and aggravate oxidative stress. After loading prodrug romidepsin (RMD) in TiO₂ @g-C₃ N₄ , stimulus-responsive drug delivery can be realized by US irradiation. The disulfide bridge of the released RMD tends to be reduced by glutathione (GSH) into a monocyclic dithiol, which arrests cell cycle in G2/M phase and evokes apoptosis through enhanced histone acetylation. Importantly, reactive oxygen species accumulation accompanied by GSH depletion is devoted to deleterious redox dyshomeostasis, leading to augmented systemic oncotherapy by eliciting antitumor immunity. Collectively, this paradigm provides useful insights in optimizing the performance of TiO₂ -based nano-sonosensitizers for tackling critical diseases.

Morin Sensitizes MDA-MB-231 Triple-Negative Breast Cancer Cells to Doxorubicin Cytotoxicity by Suppressing FOXM1 and Attenuating EGFR/STAT3 Signaling Pathways

Considerable emphasis is being placed on combinatorial chemotherapeutic/natural treatments for breast cancer. This study reveals the synergistic anti-tumor activity of morin and Doxorubicin (Dox) co-treatment on MDA-MB-231 triple-negative breast cancer (TNBC) cell proliferation. Morin/Dox treatment promoted Dox uptake and induced DNA damage and formation of nuclear foci of p-H2A.X. Furthermore, DNA repair proteins, RAD51 and survivin, and cell cycle proteins, cyclin B1 and forkhead Box M1 (FOXM1), were induced by Dox alone but attenuated by morin/Dox co-treatment. In addition, Annexin V/7-AAD analysis revealed that necrotic cell death after co-treatment and apoptotic cell death by Dox alone were associated with the induction of cleaved PARP and caspase-7 without Bcl-2 family involvement. FOXM1 inhibition by thiostrepton showed that co-treatment caused FOXM1-mediated cell death. Furthermore, co-treatment downregulated the phosphorylation of EGFR and STAT3. Flow cytometry showed that the accumulation of cells in the G2/M and S phases might be linked to cellular Dox uptake, p21 upregulation, and cyclin D1 downregulation. Taken together, our study shows that the anti-tumor effect of morin/Dox co-treatment is due to the suppression of FOXM1 and attenuation of EGFR/STAT3 signaling pathways in MDA-MB-231 TNBC cells, which suggests that morin offers a means of improving therapeutic efficacy in TNBC patients.

"Half-Sandwich" Ruthenium Complexes with Alizarin as Anticancer Agents: In Vitro and In Vivo Studies

Upon exploration of the chemistry of the combination of ruthenium/arene with anthraquinone alizarin (L), three new complexes with the general formulas [Ru(L)Cl(η⁶-p-cymene)] (C1), [Ru(L)(η⁶-p-cymene)(PPh₃)]PF₆ (C2), and [Ru(L)(η⁶-p-cymene)(PEt₃)]PF₆ (C3) were synthesized and characterized using spectroscopic techniques (mass, IR, and 1D and 2D NMR), molar conductivity, elemental analysis, and X-ray diffraction. Complex C1 exhibited fluorescence, such as free alizarin, while in C2 and C3, the emission was probably quenched by monophosphines and the crystallographic data showed that hydrophobic interactions are predominant in intermolecular contacts. The cytotoxicity of the complexes was evaluated in the MDA-MB-231 (triple-negative breast cancer), MCF-7 (breast cancer), and A549 (lung) tumor cell lines and MCF-10A (breast) and MRC-5 (lung) nontumor cell lines. Complexes C1 and C2 were more selective to the breast tumor cell lines, and C2 was the most cytotoxic (IC₅₀ = 6.5 μM for MDA-MB-231). In addition, compound C1 performs a covalent interaction with DNA, while C2 and C3 present only weak interactions; however, internalization studies by flow cytometry and confocal microscopy showed that complex C1 does not accumulate in viable MDA-MB-231 cells and is detected in the cytoplasm only after cell permeabilization. Investigations of the mechanism of action of the complexes indicate that C2 promotes cell cycle arrest in the Sub-G₁ phase in MDA-MB-231, inhibits its colony formation, and has a possible antimetastatic action, impeding cell migration in the wound-healing experiment (13% of wound healing in 24 h). The in vivo toxicological experiments with zebrafish indicate that C1 and C3 exhibit the most zebrafish embryo developmental toxicity (inhibition of spontaneous movements and heartbeats), while C2, the most promising anticancer drug in the in vitro preclinical tests, revealed the lowest toxicity in in vivo preclinical screening.

5-Demethylnobiletin mediates cell cycle arrest and apoptosis via the ERK1/2/AKT/STAT3 signaling pathways in glioblastoma cells

5-Demethylnobiletin is the active ingredient in citrus polymethoxyflavones that could inhibit the proliferation of several tumor cells. However, the anti-tumor effect of 5-Demethylnobiletin on glioblastoma and the underlying molecular mechanisms are remains unknown. In our study, 5-Demethylnobiletin markedly inhibited the viability, migration and invasion of glioblastoma U87-MG, A172 and U251 cells. Further research revealed that 5-Demethylnobiletin induces cell cycle arrest at the G0/G1 phase in glioblastoma cells by downregulating Cyclin D1 and CDK6 expression levels. Furthermore, 5-Demethylnobiletin significantly induced glioblastoma cells apoptosis by upregulating the protein levels of Bax and downregulating the protein level of Bcl-2, subsequently increasing the expression of cleaved caspase-3 and cleaved caspase-9. Mechanically, 5-Demethylnobiletin trigged G0/G1 phase arrest and apoptosis by inhibiting the ERK1/2, AKT and STAT3 signaling pathway. Furthermore, 5-Demethylnobiletin inhibition of U87-MG cell growth was reproducible in vivo model. Therefore, 5-Demethylnobiletin is a promising bioactive agent that might be used as glioblastoma treatment drug.

Exploring the Phytochemical Profile and Biological Activities of Clerodendrum infortunatum

Clerodendrum infortunatum (C. infortunatum), the hill glory bower, is reputed as the prodigious treasure for Indian folk medicine. The study has focused on exploring the phytochemistry and antitumor potential of the C. infortunatum root extract in vitro and in vivo. The ethyl acetate root extract has demonstrated the highest cytotoxicity in a series of nine human tumor cell lines. Further fractionation of the same has yielded seven compounds. The structures of these compounds were confirmed with spectroscopic techniques. Considering the toxicity observed with the crude extract, cytotoxicity of these compounds was further assessed in two breast carcinoma cell lines (MCF-7[ER/PR-positive HER2-negative] and MDA-MB-231 [ER/PR/HER2-negative]) and in two cervical cancer [human papilloma virus (HPV)-negative C33A and HPV-positive SiHa] cell lines. Betulinic acid (BA) was found as the active principle contributing the cytotoxic activity, and cervical cancer cell lines documented the minimum IC₅₀ value in 24 h. In order to validate the in vitro experimental data, we have established a xenograft model of HPV-positive cervical cancer in female NOD/SCID mice treated with BA using doxorubicin as the positive control. BA treatment gradually reduced the tumor size, maintaining healthy hematological and biochemical parameters, and improved the survival rate of tumor-bearing mice considerably. Thus, our findings suggest that the C. infortunatum root extract has a promising anticancer property against HPV-positive cervical cancer and supports its usage by traditional healers for treating cervical cancer.

Cinobufacini injection suppresses the proliferation of human osteosarcoma cells by inhibiting PIN1-YAP/TAZ signaling pathway

Cinobufacini injection (CI), an aqueous extract of Cutis Bufonis, is clinically used for cancer therapy in China, but its molecular mechanism for the treatment of osteosarcoma (OS) remains unclear. We constructed U2OS ectopic subcutaneous tumor model to verify the anti-OS effect of CI in vivo. Meanwhile, cell proliferation of U2OS and MG63 cells was monitored in vitro using the CCK-8 assay, colony formation and morphological changes. Cell cycle arrest and apoptosis were detected by flow cytometry and western blot, which showed that CI significantly inhibited proliferation, induced cell cycle arrest and apoptosis in human OS cells. The further RNA-seq results identified that the Hippo signaling pathway was involved in the anti-OS effect of CI. YAP/TAZ are two major components of the Hippo pathway in breast cancer and are positively regulated by prolyl isomerase PIN1, we assessed their role in OS using both clinicopathological sections and western blots. CI also inhibited PIN1 enzyme activity in a dose-dependent manner, which resulted in impaired PIN1, YAP, and TAZ expression in vitro and in vivo. Additionally, 15 potential compounds of CI were found to occupy the PIN1 kinase domain and inhibit its activity. In summary, CI plays an anti-OS role by down-regulating the PIN1-YAP/TAZ pathway.

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.

Novel pentacyclic derivatives and benzylidenes of the progesterone series cause anti-estrogenic and antiproliferative effects and induce apoptosis in breast cancer cells

The promising antitumor effects of progesterone derivatives have been identified in many studies. However, the specific mechanism of action of this class of compounds has not been fully described. Therefore, in this study, we investigated the antiproliferative and (anti)estrogenic activities of novel pentacyclic derivatives and benzylidenes of the progesterone series. The antiproliferative effects of the compounds were evaluated on hormone-dependent MCF7 breast cancer cells using the MTT test. Estrogen receptor α (ERα) activity was assessed by a luciferase-based reporter assay. Immunoblotting was used to evaluate the expression of signaling proteins. All benzylidenes demonstrated inhibitory effects with IC₅₀ values below 10 µM, whereas pentacyclic derivatives were less active. These patterns may be associated with the lability of the geometry of benzylidene molecules, which contributes to an increase in the affinity of interaction with the receptor. The selected compounds showed significant anti-estrogenic potency. Benzylidene 1d ((8 S,9 S,10R,13 S,14 S,17 S)-17-[(2E)-3-(4-fluorophenyl)prop-2-enoyl]-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15-decahydrocyclopenta[a]phenanthren-3-one) was the most active in antiproliferative and anti-estrogenic assays. Apoptosis induced by compound 1d was accompanied by decreases in CDK4, ERα, and Cyclin D1 expression. Compounds 1d and 3d were characterized by high inhibitory potency against resistant breast cancer cells. Apoptosis induced by the leader compounds was confirmed by PARP cleavage and flow cytometry analysis. Compound 3d caused cell arrest in the G2/M phase. Further analysis of novel derivatives of the progesterone series is of great importance for medicinal chemistry, drug design, and oncology.

Hyperthermia-stimulated tonsil-mesenchymal stromal cells suppress hematological cancer cells through downregulation of IL-6

There are contradictory reports on the use of mesenchymal stromal cells (MSCs) in cancer therapy. Variable outcomes have been associated with several factors including cancer pathology, experimental procedure, MSC source tissue, and individual genetic differences. It is also known that MSCs exert their therapeutic effects with various paracrine factors released from these cells. The profiles of the factors released from MSCs are altered by heat shock, hypoxia, oxidative stress, starvation or various agents such as inflammatory cytokines, and their therapeutic potential is affected. In this study, the antitumor potential of conditioned media (CM), which contains paracrine factors, of mild hyperthermia-stimulated mesenchymal stromal cells derived from lymphoid organ tonsil tissue (T-MSC) was investigated in comparison with CM obtained from T-MSCs grew under normal culture conditions. CM was obtained from T-MSCs that were successfully isolated from palatine tonsil tissue and characterized. The cytotoxic effect of CM on the growth of hematological cancer cell lines at different concentrations (1:1 and 1:2) was demonstrated by methylthiazoldiphenyl-tetrazolium bromide analysis. In addition, the apoptotic effect of T-MSC-CM treatment was evaluated on the cancer cells using Annexin-V/PI detection method by flow cytometry. The pro/anti-apoptotic and cytokine-related gene expressions were also analyzed by real-time polymerase chain reaction post T-MSC-CM treatment. In conclusion, we demonstrated that the factors released from hyperthermia-stimulated T-MSCs induced apoptosis in hematological cancer cell lines in a dose-dependent manner. Importantly, our results at the transcriptional level support that the factors and cytokines released from hyperthermia-stimulated T-MSC may exert antitumoral effects in cancer cells by downregulation of IL-6 that promotes tumorigenesis. These findings reveal that T-MSC-CM can be a powerful cell-free therapeutical strategy for cancer therapy.

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.

Proximal discrepancy in intrinsic atomic interaction arrests G2/M phase by inhibiting Cyclin B1/CDK1 to infer molecular and cellular biocompatibility of D-limonene

The quest for different natural compounds for different biomedical applications especially in the treatment of cancer is at a high pace with increasing incidence of severity. D-limonene has been portrayed as one of the effective potential candidate centered to the context of breast cancer. The anticipation of its count as an effective biomedical agent required a detailed understanding of their molecular mechanism of biocompatibility. This study elucidates the mechanistic action of D-limonene channelized by the induction of apoptosis for controlling proliferation in breast cancer cells. The possible mechanism was explored through an experimental and computational approach to estimate cell proliferation inhibition, cell cycle phase distribution, apoptosis analysis using a flow cytometry, western blotting and molecular docking. The results showed reduced dose and time-dependent viability of MCF7 cells. The study suggested the arrest of the cell cycle at G2/M phase leading to apoptosis and other discrepancies of molecular activity mediated via significant alteration in protein expression pattern of anti-apoptotic proteins like Cyclin B1 and CDK1. Computational analysis showed firm interaction of D-limonene with Cyclin B1 and CDK1 proteins influencing their structural and functional integrity indicating the mediation of mechanism. This study concluded that D-limonene suppresses the proliferation of breast cancer cells by inducing G2/M phase arrest via deregulation of Cyclin B1/CDK1.

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.

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.

Chemically synthesized cinobufagin suppresses nasopharyngeal carcinoma metastasis by inducing ENKUR to stabilize p53 expression

Clinically, the metastasis of tumor cells is the key factor of death in patients with cancer. In this study, we used a model of metastatic nasopharyngeal carcinoma (NPC) to explore the effects of a new chemical, cinobufagin (CB), combined with cisplatin (DDP). We observed that chemically synthesized CB strongly decreased the metastasis of NPC. Furthermore, a better therapeutic effect was shown when CB was combined with DDP. Molecular analysis revealed that CB induced ENKUR expression by deregulating the PI3K/AKT pathway and suppressing c-Jun, an oncogenic transcriptional factor that binds to the ENKUR promoter and negatively modulated its expression in NPC. ENKUR as a tumor suppressor binds to MYH9 and decreases its expression by recruiting β-catenin via its enkurin domain to prevent its nuclear accumulation, which therefore suppresses c-Jun-induced MYH9 expression. Subsequently, downregulated MYH9 reduces the enlistment of E3 ligase UBE3A and thus decreases the UBE3A-mediated ubiquitination degradation of p53, a key tumor suppressor that decreases epithelial-mesenchymal transition (EMT). Clinical sample analysis demonstrated that the ENKUR expression level was significantly reduced in NPC tissues. Its decreased expression substantially promoted clinical progression and reflected poor prognosis for patients with NPC. This study demonstrated that CB induced ENKUR to repress the β-catenin/c-Jun/MYH9 signal and thus decreased UBE3A-mediated p53 ubiquitination degradation. As a result, the EMT signal was inactivated to suppress NPC metastasis.

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.

Evaluation of anticancer activity in vitro of a stable copper(I) complex with phosphine-peptide conjugate

[CuI(2,9-dimethyl-1,10-phenanthroline)P(p-OCH₃-Ph)₂CH₂SarcosineGlycine] (1-MPSG), highly stable in physiological media phosphino copper(I) complex—is proposed herein as a viable alternative to anticancer platinum-based drugs. It is noteworthy that, 1-MPSG significantly and selectively reduced cell viability in a 3D spheroidal model of human lung adenocarcinoma (A549), in comparison with non-cancerous HaCaT cells. Confocal microscopy and an ICP-MS analysis showed that 1-MPSG effectively accumulates inside A549 cells with colocalization in mitochondria and nuclei. A precise cytometric analysis revealed a predominance of apoptosis over the other types of cell death. In the case of HaCaT cells, the overall cytotoxicity was significantly lower, indicating the selective activity of 1-MPSG towards cancer cells. Apoptosis also manifested itself in a decrease in mitochondrial membrane potential along with the activation of caspases-3/9. Moreover, the caspase inhibitor (Z-VAD-FMK) pretreatment led to decreased level of apoptosis (more pronouncedly in A549 cells than in non-cancerous HaCaT cells) and further validated the caspases dependence in 1-MPSG-induced apoptosis. Furthermore, the 1-MPSG complex presumably induces the changes in the cell cycle leading to G2/M phase arrest in a dose-dependent manner. It was also observed that the 1-MPSG mediated intracellular ROS alterations in A549 and HaCaT cells. These results, proved by fluorescence spectroscopy, and flow cytometry, suggest that investigated Cu(I) compound may trigger apoptosis also through ROS generation.

Janerin Induces Cell Cycle Arrest at the G2/M Phase and Promotes Apoptosis Involving the MAPK Pathway in THP-1, Leukemic Cell Line

Janerin is a cytotoxic sesquiterpene lactone that has been isolated and characterized from different species of the Centaurea genus. In this study, janerin was isolated form Centaurothamnus maximus, and its cytotoxic molecular mechanism was studied in THP-1 human leukemic cells. Janerin inhibited the proliferation of THP-1 cells in a dose-dependent manner. Janerin caused the cell cycle arrest at the G2/M phase by decreasing the CDK1/Cyclin-B complex. Subsequently, we found that janerin promoted THP-1 cell death through apoptosis as indicated by flow cytometry. Moreover, apoptosis induction was confirmed by the upregulation of Bax, cleaved PARP-1, and cleaved caspase 3 and the downregulation of an anti-apoptotic Bcl-2 biomarker. In addition, immunoblotting indicated a dose dependent upregulation of P38-MAPK and ERK1/2 phosphorylation during janerin treatment. In conclusion, we have demonstrated for the first time that janerin may be capable of inducing cell cycle arrest and apoptosis through the MAPK pathway, which would be one of the mechanisms underlying its anticancer activity. As a result, janerin has the potential to be used as a therapeutic agent for leukemia.

Curcumin Reduces Colorectal Cancer Cell Proliferation and Migration and Slows In Vivo Growth of Liver Metastases in Rats

Background: New therapeutic approaches are an essential need for patients suffering from colorectal cancer liver metastases. Curcumin, a well-known plant-derived polyphenol, has been shown to play a role in the modulation of multiple signaling pathways involved in the development and progression of certain cancer cells in vitro. This study aims to assess the anti-tumor effect of curcumin on CC531 colorectal cancer cells, both in vitro and in vivo. Methods: On CC531 cultures, the cell viability and cell migration capacity were analyzed (wound healing test) 24, 48, and 72 h after treatment with curcumin (15, 20, 25, or 30 µM). Additionally, in WAG/RijHsd tumor-bearing rats, the total and individual liver lobe tumor volume was quantified in untreated and curcumin-treated animals (200 mg/kg/day, oral). Furthermore, serum enzyme measurements (GOT, GPT, glucose, bilirubin, etc.) were carried out to assess the possible effects on the liver function. Results: In vitro studies showed curcumin’s greatest effects 48h after application, when all of the tested doses reduced cell proliferation by more than 30%. At 72 h, the highest doses of curcumin (25 and 30 µM) reduced cell viability to less than 50%. The wound healing test also showed that curcumin inhibits migration capacity. In vivo, curcumin slowed down the tumor volume of liver implants by 5.6-fold (7.98 ± 1.45 vs. 1.41 ± 1.33; p > 0.0001). Conclusions: Curcumin has shown an anti-tumor effect against liver implants from colorectal cancer, both in vitro and in vivo, in this experimental model.

Cytotoxic Activity of Isoniazid Derivative in Human Breast Cancer Cells

BACKGROUND/AIM

Isoniazid is an antibiotic used for the treatment of tuberculosis. Previously, we found that the isoniazid derivative (E)-N'-(2,3,4-trihydroxybenzylidene) isonicotinohydrazide (ITHB4) could be developed as novel antimycobacterial agent by lead optimization. We further explored the ability of this compound compared to zerumbone in inhibiting the growth of MCF-7 breast cancer cells.

MATERIALS AND METHODS

Cytotoxicity was measured by the MTT assay and further confirmed via apoptosis, ROS, cell cycle, DNA fragmentation and cytokine assays.

RESULTS

ITHB4 demonstrated a lower IC₅₀ compared to zerumbone in inhibiting the proliferation of MCF-7 cells. ITHB4 showed no toxicity against normal breast and human immune cells. Apoptosis assay revealed that ITHB4, at a concentration equal to the IC₅₀, induces apoptosis of MCF-7 cells and cell cycle arrest at the sub-G1 and G₂/M phases. ITHB4 triggered accumulation of intracellular ROS and nuclear DNA fragmentation. Secretion of pro-inflammatory cytokines induced inflammation and potentially immunogenic cell death.

CONCLUSION

ITHB4 has almost similar chemotherapeutic properties as zerumbone in inhibiting MCF-7 growth, and hence provide the basis for further experiments in animal models.

AKR1B10 protects against UVC-induced DNA damage in breast cancer cells

The cellular response to DNA damage is crucial for maintaining the integrity and stability of molecular structure. To maintain genome stability, DNA-damaged cells should be arrested so that mutations can be repaired before replication. Although several key components required for this arrest have been discovered, the majority of the pathways are still unclear. Through a number of assays, including cell viability, colony formation, and apotheosis assay, we found that AKR1B10 protected cells from UVC-induced DNA damage. Surprisingly, UVC-induced γH2AX foci and DNA double-strand breaks in the AKR1B10-overexpressing cells were ∼4-5 folds lower than those in the control group. The expression levels of AKR1B10, p53, chk1, chk2, nuclear factor (NF)-κB, and p65 showed dynamic changes in response to UVC irradiation. Our results suggested that AKR1B10 is involved in the pathway of cell cycle checkpoint and NF-κB in DNA damage. Taken together, our results suggest that AKR1B10 is involved in the repair of the DNA double-strand break, which provides a new insight into the role of AKR1B10 in DNA damage repair and indicates a new trail in tumorigenesis and cancer drug resistance.

Tiliacora racemosa leaves induce oxidative stress mediated DNA damage leading to G2/M phase arrest and apoptosis in cervical cancer cells SiHa

ETHNOPHARMACOLOGICAL RELEVANCE

The Menispermaceae plant Tiliacora racemosa is immensely popular in Indian traditional Ayurvedic medicine as "Krishnavetra" for its remarkable anti-cancerous property, and is commonly used by tribal population for the treatment of skin infections, snake bites and filariasis.

AIM OF THE STUDY

This present study intends to identify the modus operandi behind the cytotoxic activity of Tiliacora racemosa leaves in cervical cancer cells SiHa. Focus has been instilled in the ability of the plant extract to target multiple signaling pathways leading to cell cycle arrest and cell death in SiHa cells, followed by a pharmacological characterization to identify the bioactive principle.

MATERIALS AND METHODS

T. racemosa leaves extracted in methanol, ethyl acetate, hexane and aqueous solvent were screened for cytotoxicity in HeLa, SiHa, C33A (cervical cancer cells) and HEK cells by MTT assay. SiHa cells were treated with the most potent extract (TRM). Cellular morphology, clonogenic and wound healing potential, presence of intracellular ROS and NO, lipid peroxidation, activity of cellular antioxidants (SOD, CAT, GSH), DNA damage detection by comet assay and localisation of γ-H2AX foci, intracellular expression of PARP-1, Bax/Bcl2 and caspase-3, loss in mitochondrial membrane potential by JC1 (flow cytometry) and Rh123 (microscopy), cell cycle analysis, Annexin-FITC assay, AO/EtBr microscopy and apoptotic proteome profiling were undertaken in the treated cells. All the related proteins were studied by immunoblots. Effect of NAC (ROS-scavenger) on cell viability, DNA damage and apoptosis were studied. Phytochemical characterization of all TR extracts was followed by LC-MS analysis of TRM and isolated alkaloid of TR was assessed for cytotoxicity.

RESULTS

The methanol extract of T. racemosa (TRM) rich in bisbenzylisoquinoline and other alkaloids impeded the proliferation of cervical cancer cells SiHa in vitro through disruption of cellular redox homeostasis caused by increase in cellular ROS and NO with concomitant decrease in the cellular antioxidants. Double-stranded DNA damage was noted from γH2AX foci accumulation and Parp-1 activation leading to ATM-Chk2-p53 pathway arresting the cells at G2/M-phase through cyclin B1 inhibition. The mitochondrial membrane potential was also disturbed leading to caspase-3 dependent apoptotic induction by both extrinsic and intrinsic pathway. Immunoblots show TRM also inhibited PI3K/Akt and NFκB pathway. NAC pre-treatment rescued the cell viability proving DNA damage and apoptosis to be direct consequences of ROS overproduction. Lastly, the therapeutic potential of T. racemosa is was hypothesized to be possibly derived from its alkaloid content.

CONCLUSION

This study proves the age old ethnnopharmacological anticancer role of T. racemosa. The leaf extracts inhibited the anomalous proliferation of SiHa cells by virtue of G2/M-phase cell cycle arrest and apoptotic cell death. Oxidative stress mediated double stranded DNA damage paved the way towards apoptotic cell death through multiple routes, including PI3K/Akt/NFκB pathway. The abundant alkaloid content of T. racemosa was denoted as the probable responsible cytotoxic principle.

KIFC1 regulates ZWINT to promote tumor progression and spheroid formation in colorectal cancer

Colorectal cancer (CRC) is the second leading cause of cancer-related mortality worldwide. Kinesin Family Member C1 (KIFC1) has been proposed as a promising therapeutic target due to its pivotal role in centrosome clustering to mediate cancer cell progression. This study aimed to analyze the expression and biological function of KIFC1 in CRC. Immunohistochemically, 67 (52%) of 129 CRC cases were positive for KIFC1 and statistically associated with poorer overall survival. KIFC1 small interfering RNA (siRNA)-transfected cells demonstrated lower cell proliferation as compared to the negative control cells. A specific KIFC1 inhibitor, kolavenic acid analog (KAA) drastically inhibited CRC cell proliferation. Microarray analysis revealed that KAA-treated CRC cells presented reduced ZW10 interacting kinetochore protein (ZWINT) expression as compared to control cells. Immunohistochemical analysis demonstrated that 61 (47%) of 129 CRC cases were positive for ZWINT and ZWINT expression was significantly correlated with KIFC1 expression. ZWINT-positive cases exhibited significantly worse overall survival. KIFC1 siRNA-transfected cells showed reduced ZWINT expression while ZWINT siRNA-transfected cells decreased cell proliferation. Both KIFC1 and ZWINT knockdown cells attenuated spheroid formation ability. This study provides new insights into KIFC1 regulating ZWINT in CRC progression and its potential as a therapeutic target.

Sophoridine Inhibits the Tumour Growth of Non-Small Lung Cancer by Inducing Macrophages M1 Polarisation via MAPK-Mediated Inflammatory Pathway

Lung cancer is one of the most common and lethal neoplasms for which very few efficacious treatments are currently available. M1-like polarised tumour-associated macrophages (TAMs) are key mediators to modulate the tumour microenvironment, which play a key role in inhibiting cancer cell growth. Sophoridine, a naturally occurring alkaloid, exerts multiple pharmacological activities including anti-tumour and anti-inflammatory activities, but it has not been characterised as a regulator of tumour microenvironment towards NSCLC. Herein, the regulatory effects of sophoridine on the polarisation of THP-1 cells into TAMs and the anti-tumour effects of sophoridine-stimulated M1 polarised macrophages towards lung cancer cells were carefully investigated both in vitro and in vivo. The results showed that sophoridine could significantly promote M1 polarisation of RAW264.7 and THP-1-derived macrophages, leading to increased expression of pro-inflammatory cytokines and the M1 surface markers CD86 via activating MAPKs signaling pathway. Further investigations showed that sophoridine-stimulated RAW264.7 and THP-1-derived M1 macrophages effectively induced cell apoptosis as well as inhibited the cell colony formation and cell proliferation in both H460 and Lewis lung cancer cells. In Lewis-bearing mice model, sophoridine (15 or 25 mg/kg) significantly inhibited the tumour growth and up-regulated the expression of CD86/F4/80 in tumour tissues. Collectively, the findings clearly demonstrate that sophoridine promoted M1-like polarisation in vitro and in vivo, suggesting that sophoridine held a great therapeutic potential for treating lung cancer.

NCAPG upregulation mediated by four microRNAs combined with activation of the p53 signaling pathway is a predictor of poor prognosis in patients with breast cancer

The role of non-SMC condensin I complex subunit G (NCAPG) in breast cancer remains unclear. The present study used online databases, reverse transcription-quantitative PCR, flow cytometry and western blotting to determine the expression levels, prognosis and potential molecular mechanisms underlying the role of NCAPG in breast cancer. The association between NCAPG expression and several different clinicopathological parameters in patients with breast cancer was determined, and the results revealed that NCAPG expression was negatively associated with estrogen receptor and progesterone receptor positive status, but was positively associated with HER2 positive status, Nottingham Prognostic Index score and Scarff-Bloom-Richardson grade status. Furthermore, upregulated expression levels of NCAPG resulted in a poor prognosis in patients with breast cancer. A total of 27 microRNAs (miRNAs/miRs) were predicted to target NCAPG, among which four miRNAs (miR-101-3p, miR-195-5p, miR-214-3p and miR-944) were predicted to most likely regulate NCAPG expression in breast cancer. A total of 261 co-expressed genes of NCAPG were identified, including cell division cyclin 25 homolog C (CDC25C), and pathway enrichment analysis indicated that these co-expressed genes were significantly enriched in the p53 signaling pathway. CDC25C expression was downregulated in breast cancer and was associated with a poor prognosis. These findings suggested that upregulated NCAPG expression may be a prognostic biomarker of breast cancer.

Homoharringtonine inhibits melanoma cells proliferation in vitro and vivo by inducing DNA damage, apoptosis, and G2/M cell cycle arrest

Homoharringtonine (HHT), an approved anti-leukemic alkaloid, has been reported effectively in many types of tumor cells. However, its effect on melanoma cells has not been investigated. And the anti-melanoma mechanism of HHT is still unknown. In this study, we detected the effects of HHT on two melanoma cell lines (A375 and B16F10) and on the A375 xenograft mouse model. HHT significantly inhibited the proliferation of melanoma cells as investigated by the CCK8 method, cell cloning assay, and EdU experiment. HHT induced A375 and B16F10 cells DNA damage, apoptosis, and G2/M cell cycle arrest as proved by TdT-mediated dUTP Nick-End Labeling (TUNEL) and flow cytometry assay. Additionally, the loss of mitochondrial membrane potential in HHT-treated cells were visualized by JC-1 fluorescent staining. For the molecule mechanism study, western blotting results indicated the protein expression levels of ATM, P53, p-P53, p-CHK2, γ-H2AX, PARP, cleaved-PARP, cleaved caspase-3, cleaved caspase-9, Bcl-2, Bax, Aurka, p-Aurka, Plk1, p-Plk1, Cdc25c, CDK1, cyclin B1, and Myt1 were regulated by HHT. And the relative mRNA expression level of Aurka, Plk1, Cdc25c, CDK1, cyclin B1, and Myt1 were ascertained by q-PCR assay. The results in vivo experiment showed that HHT can slow down the growth rate of tumors. At the same time, the protein expression levels in vivo were consistent with that in vitro. Collectively, our study provided evidence that HHT could be considered an effective anti-melanoma agent by inducing DNA damage, apoptosis, and cell cycle arrest.

Antioxidant Molecules from Plant Waste: Extraction Techniques and Biological Properties

The fruit, vegetable, legume, and cereal industries generate many wastes, representing an environmental pollution problem. However, these wastes are a rich source of antioxidant molecules such as terpenes, phenolic compounds, phytosterols, and bioactive peptides with potential applications mainly in the food and pharmaceutical industries, and they exhibit multiple biological properties including antidiabetic, anti-obesity, antihypertensive, anticancer, and antibacterial properties. The aforementioned has increased studies on the recovery of antioxidant compounds using green technologies to value plant waste, since they represent more efficient and sustainable processes. In this review, the main antioxidant molecules from plants are briefly described and the advantages and disadvantages of the use of conventional and green extraction technologies used for the recovery and optimization of the yield of antioxidant naturals are detailed; finally, recent studies on biological properties of antioxidant molecules extracted from plant waste are presented here.

An Overview of Privileged Scaffold: Quinolines and Isoquinolines in Medicinal Chemistry as Anticancer Agents

Cancer is one of the most difficult diseases and causes of death for many decades. Many pieces of research are continuously going on to get a solution for cancer. Quinoline and isoquinoline derivatives have shown their possibilities to work as an antitumor agent in anticancer treatment. The members of this privileged scaffold quinoline and isoquinoline have shown their controlling impacts on cancer treatment through various modes. In particular, this review suggests the current scenario of quinoline and isoquinoline derivatives as antitumor agents and refine the path of these derivatives to find and develop new drugs against an evil known as cancer.

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.