Natural compound library screening identifies Sanguinarine chloride for the treatment of SCLC by upregulating CDKN1A

Angelic acid triggers ferroptosis in colorectal cancer cells via targeting and impairing NRF2 protein stability

Ferroptosis is a unique programmed cell death driven by iron-dependent phospholipid peroxidation. Tumor cells that escape from the conventional therapies appear more sensitive to ferroptosis. Therefore, it is extremely urgent to find safe and efficient active ingredients that induce ferroptosis in tumor cells. Herein, we identified that angelic acid, as a potent anti-tumor active ingredient in Angelica sinensis, profoundly sensitizes CRC cells to ferroptosis via a natural compound library screen. We revealed that angelic acid treatment is sufficient to predispose CRC cells to ferroptosis phenotype, evidenced by malondialdehyde (MDA) accumulation, lipid peroxidation, and upregulation of ferroptosis-associated markers CHAC1 and PTGS2, which is abolished by ferroptosis inhibitor Fer-1. Moreover, the results of network pharmacology showed that NRF2 is critical for angelic acid-mediated CRC cell ferroptosis. Mechanistically, angelic acid exerted its ferroptosis induction via directly binding and facilitating the degradation of NRF2. In addition, the syngeneic mouse models revealed that angelic acid boosts CRC cell sensitivity to ferroptosis inducer sulfasalazine with essentially no toxicity in vivo. Collectively, our findings highlighted a previously unrecognized anti-tumor mechanism of angelic acid and represented an appealing therapeutic strategy for CRC treatment.

Exploring the Potential of Cyclic Peptidyl Antitumor Agents Derived from Natural Macrocyclic Peptide Phakellistatin

The exploration of novel anticancer compounds based on natural cyclopeptides has emerged as a pivotal paradigm in the contemporary advancement of macrocyclic pharmaceuticals. Phakellistatin 13 is a cycloheptapeptide derived from the brown snubby sponge and exhibits remarkable antitumor activity. In this study, we have designed and synthesized a series of chiral cyclopeptides incorporating the rigid isoindolinone moiety at various sites within the natural cycloheptapeptide Phakellistatin 13, with the aim of investigating conformationally constrained cyclopeptides as potential antitumor agents. Cyclopeptide 3, comprising alternating l-/d-amino acid residues, exhibited promising antihepatocellular carcinoma effects. Detailed biological experiments have revealed that Phakellistatin 13 analogs effectively inhibit the proliferation of tumor cells and induce apoptosis and autophagy, while also causing cell cycle arrest through the modulation of the p53 and mitogen-activated protein kinase (MAPK) signaling pathway. This study not only provides valuable insights into chemical structural modifications but also contributes to a deeper understanding of the biological mechanisms underlying the development of natural cyclopeptide-based drugs.

Bioactivity and mechanism of action of sanguinarine and its derivatives in the past 10 years

Sanguinarine is a quaternary ammonium benzophenanthine alkaloid found in traditional herbs such as Chelidonium, Corydalis, Sanguinarum, and Borovula. It has been proven to possess broad-spectrum biological activities, such as antitumor, anti-inflammatory, antiosteoporosis, neuroprotective, and antipathogenic microorganism activities. In this paper, recent progress on the biological activity and mechanism of action of sanguinarine and its derivatives over the past ten years is reviewed. The results showed that the biological activities of hematarginine and its derivatives are related mainly to the JAK/STAT, PI3K/Akt/mTOR, NF-κB, TGF-β, MAPK and Wnt/β-catenin signaling pathways. The limitations of using sanguinarine in clinical application are also discussed, and the research prospects of this subject are outlined. In general, sanguinarine, a natural medicine, has many pharmacological effects, but its toxicity and safety in clinical application still need to be further studied. This review provides useful information for the development of sanguinarine-based bioactive agents.

Sanguinarine induces apoptosis in osteosarcoma by attenuating the binding of STAT3 to the single-stranded DNA-binding protein 1 (SSBP1) promoter region

BACKGROUND AND PURPOSE

Osteosarcoma, a primary malignant bone tumour prevalent among adolescents and young adults, remains a considerable challenge despite protracted progress made in enhancing patient survival rates over the last 40 years. Consequently, the development of novel therapeutic approaches for osteosarcoma is imperative. Sanguinarine (SNG), a compound with demonstrated potent anticancer properties against various malignancies, presents a promising avenue for exploration. Nevertheless, the intricate molecular mechanisms underpinning SNG's actions in osteosarcoma remain elusive, necessitating further elucidation.

EXPERIMENTAL APPROACH

Single-stranded DNA-binding protein 1 (SSBP1) was screened out by differential proteomic analysis. Apoptosis, cell cycle, reactive oxygen species (ROS) and mitochondrial changes were assessed via flow cytometry. Western blotting and quantitative real-time reverse transcription PCR (qRT-PCR) were used to determine protein and gene levels. The antitumour mechanism of SNG was explored at a molecular level using chromatin immunoprecipitation (ChIP) and dual luciferase reporter plasmids.

KEY RESULTS

Our investigation revealed that SNG exerted an up-regulated effect on SSBP1, disrupting mitochondrial function and inducing apoptosis. In-depth analysis uncovered a mechanism whereby SNG hindered the JAK/signal transducer and activator of transcription 3 (STAT3) signalling pathway, relieved the inhibitory effect of STAT3 on SSBP1 transcription, and inhibited the downstream PI3K/Akt/mTOR signalling axis, ultimately activating apoptosis.

CONCLUSIONS AND IMPLICATIONS

The study delved further into elucidating the anticancer mechanism of SNG in osteosarcoma. Notably, we unravelled the previously undisclosed apoptotic potential of SSBP1 in osteosarcoma cells. This finding holds substantial promise in advancing the development of novel anticancer drugs and identification of therapeutic targets.

Antagonistic effect of cyclin-dependent kinases and a calcium-dependent phosphatase on polyglutamine-expanded androgen receptor toxic gain of function

Spinal and bulbar muscular atrophy is caused by polyglutamine (polyQ) expansions in androgen receptor (AR), generating gain-of-function toxicity that may involve phosphorylation. Using cellular and animal models, we investigated what kinases and phosphatases target polyQ-expanded AR, whether polyQ expansions modify AR phosphorylation, and how this contributes to neurodegeneration. Mass spectrometry showed that polyQ expansions preserve native phosphorylation and increase phosphorylation at conserved sites controlling AR stability and transactivation. In small-molecule screening, we identified that CDC25/CDK2 signaling could enhance AR phosphorylation, and the calcium-sensitive phosphatase calcineurin had opposite effects. Pharmacologic and genetic manipulation of these kinases and phosphatases modified polyQ-expanded AR function and toxicity in cells, flies, and mice. Ablation of CDK2 reduced AR phosphorylation in the brainstem and restored expression of Myc and other genes involved in DNA damage, senescence, and apoptosis, indicating that the cell cycle-regulated kinase plays more than a bystander role in SBMA-vulnerable postmitotic cells.

Sanguinarine promotes apoptosis of hepatocellular carcinoma cells via regulating the miR-497-5p/CDK4 axis

OBJECTIVE

To determine the effect of sanguinarine on the biological behavior of hepatocellular carcinoma (HCC) cells via regulating the miR-497-5p/cyclin-dependent kinase 4 (CDK4) axis.

METHODS

Swiss Target Prediction was used for target prediction of sanguinarine. The targets were analyzed with KEGG enrichment analysis, and CDK4 was included in this study. Target prediction website, Diana tools enrichment analysis, and dual-luciferase reporter assay were adopted to identify the target miRNAs for CDK4. We measured expression levels of CDK4 and miR-497-5p in cancerous tissues, normal liver L02 cells, HepG2 HCC cells and sanguinarine-treated HepG2 cells. The expression of CDK4/miR-497-5p in HCC cells was intervened by treating HCC cells with sanguinarine. Cell proliferation, invasion and apoptosis were measured with CCK8, Transwell and flow cytometry, respectively.

RESULTS

CDK4 was shown to be a target for sanguinarine. Compared with L02 cells, CDK4 expression in HCC cells was significantly increased, but sanguinarine inhibited the CDK4 expression in HCC cells. The proliferation and invasion of HCC cells were inhibited, and the apoptosis was promoted by sanguinarine, but these effects were reversed by CDK4 overexpression (both P<0.05). miR-497-5p was confirmed to be a target miRNA for CDK4, and its expression was decreased in HCC cells but could be promoted by sanguinarine. The effect of miR-497-5p knockdown on HCC cells was partially reversed by si-CDK4.

CONCLUSION

Sanguinarine inhibits the proliferation and invasion of HCC cells, and induces the apoptosis of HCC cells by regulating the expression of miR-497-5p/CDK4.