Scutellarin inhibits the metastasis and cisplatin resistance in glioma cells

Natural products reverse cisplatin resistance in the hypoxic tumor microenvironment

Cisplatin is one of the most commonly used drugs for cancer treatment. Despite much progress in improving patient outcomes, many patients are resistant to cisplatin-based treatments, leading to limited treatment efficacy and increased treatment failure. The fact that solid tumors suffer from hypoxia and an inadequate blood supply in the tumor microenvironment has been widely accepted for decades. Numerous studies have shown that a hypoxic microenvironment significantly reduces the sensitivity of tumor cells to cisplatin. Therefore, understanding how hypoxia empowers tumor cells with cisplatin resistance is essential. In the fight against tumors, developing innovative strategies for overcoming drug resistance has attracted widespread interest. Natural products have historically made major contributions to anticancer drug research due to their obvious efficacy and abundant candidate resources. Intriguingly, natural products show the potential to reverse chemoresistance, which provides new insights into cisplatin resistance in the hypoxic tumor microenvironment. In this review, we describe the role of cisplatin in tumor therapy and the mechanisms by which tumor cells generate cisplatin resistance. Subsequently, we call attention to the linkage between the hypoxic microenvironment and cisplatin resistance. Furthermore, we summarize known and potential natural products that target the hypoxic tumor microenvironment to overcome cisplatin resistance. Finally, we discuss the current challenges that limit the clinical application of natural products. Understanding the link between hypoxia and cisplatin resistance is the key to unlocking the full potential of natural products, which will serve as new therapeutic strategies capable of overcoming resistance.

Therapeutic Potential of Natural Compounds in Subarachnoid Haemorrhage

Subarachnoid hemorrhage (SAH) is a common and fatal cerebrovascular disease with high morbidity, mortality and very poor prognosis worldwide. SAH can induce a complex series of pathophysiological processes, and the main factors affecting its prognosis are early brain injury (EBI) and delayed cerebral ischemia (DCI). The pathophysiological features of EBI mainly include intense neuroinflammation, oxidative stress, neuronal cell death, mitochondrial dysfunction and brain edema, while DCI is characterized by delayed onset ischemic neurological deficits and cerebral vasospasm (CVS). Despite much exploration in people to improve the prognostic outcome of SAH, effective treatment strategies are still lacking. In recent years, numerous studies have shown that natural compounds of plant origin have unique neuro- and vascular protective effects in EBI and DCI after SAH and long-term neurological deficits, which mainly include inhibition of inflammatory response, reduction of oxidative stress, anti-apoptosis, and improvement of blood-brain barrier and cerebral vasospasm. The aim of this paper is to systematically explore the processes of neuroinflammation, oxidative stress, and apoptosis in SAH, and to summarize natural compounds as potential targets for improving the prognosis of SAH and their related mechanisms of action for future therapies.

The role of flavonoids in the regulation of epithelial-mesenchymal transition in cancer: A review on targeting signaling pathways and metastasis

One of the hallmarks of cancer is metastasis, a process that entails the spread of cancer cells to distant regions in the body, culminating in tumor formation in secondary organs. Importantly, the proinflammatory environment surrounding cancer cells further contributes to cancer cell transformation and extracellular matrix destruction. During metastasis, front-rear polarity and emergence of migratory and invasive features are manifestations of epithelial-mesenchymal transition (EMT). A variety of transcription factors (TFs) are implicated in the execution of EMT, the most prominent belonging to the Snail Family Transcriptional Repressor (SNAI) and Zinc Finger E-Box Binding Homeobox (ZEB) families of TFs. These TFs are regulated by interaction with specific microRNAs (miRNAs), as miR34 and miR200. Among the several secondary metabolites produced in plants, flavonoids constitute a major group of bioactive molecules, with several described effects including antioxidant, antiinflammatory, antidiabetic, antiobesogenic, and anticancer effects. This review scrutinizes the modulatory role of flavonoids on the activity of SNAI/ZEB TFs and on their regulatory miRNAs, miR-34, and miR-200. The modulatory role of flavonoids can attenuate mesenchymal features and stimulate epithelial features, thereby inhibiting and reversing EMT. Moreover, this modulation is concomitant with the attenuation of signaling pathways involved in diverse processes as cell proliferation, cell growth, cell cycle progression, apoptosis inhibition, morphogenesis, cell fate, cell migration, cell polarity, and wound healing. The antimetastatic potential of these versatile compounds is emerging and represents an opportunity for the synthesis of more specific and potent agents.

Precise Construction of Dual-Promising Anticancer Drugs Associated with Gold Nanomaterials on Glioma Cancer Cells

Multiple chemodrugs with nanotechnology have proven to be an effective cancer treatment technique. When taken combined, cabazitaxel (CTX) and cisplatin (PT) have more excellent cytotoxic effects than drugs used alone in the chemotherapy of several different cancers. However, several severe side effects are associated with using these chemotherapy drugs in cancer patients. Gold nanomaterials (AuNMs) are promising as drug carriers because of their small diameter, easy surface modifications, good biocompatibility, and strong cell penetration. This work aimed to determine the CTX and PT encapsulated with AuNMs against human glioma U87 cancer cells. The fabrication of the AuNMs achieved a negative surface charge, polydispersity index, and the mean sizes. The combined cytotoxic effect of CTX and PT bound to AuNMs was greater than that of either drug alone when tested on U87 cells. The half inhibitory concentration (IC50) values for free PT were 54.7 μg/mL (at 24 h) and 4.8 g μg/mL (at 72 h). Results acquired from the MTT assay show cell growth decreases time- and concentration-dependent AuNMs, free CTX, free PT, and AuNMs@CTX/PT-induced cytotoxicity and, ultimately, the cell death of U87 cells via apoptosis. The biochemical apoptosis staining techniques investigated the cells' morphological changes of the cells (acridine orange and ethidium bromide (AO-EB) and nuclear staining (DAPI) techniques). The AO-EB and nuclear staining results reveal that the NPs effectively killed cancer cells. Furthermore, the flow cytometry analysis examined the mode of cell death. Therefore, AuNMs@CTX/PT has excellent potential in the cancer therapy of different cancer cells.

Scutellarin Inhibits Glioblastoma Growth in a Dose-dependent Manner by Suppressing the p63 Signaling Pathway

Although scutellarin has been extensively investigated, its effects on glioma are unclear. This study intended to reveal this regulation and the underlying mechanisms. The U251, M059K, and SF-295 cell lines were treated with gradient concentrations of scutellarin and then IC50 was calculated. SF-295 cells selected for subsequent procedures were treated with four concentrations of scutellarin. Then, proliferation, apoptosis, and cell cycle, as well as the protein and mRNA expression of significantly differentially expressed genes identified by next-generation sequencing (NGS), were examined. The curative effect of scutellarin was validated by 5-FU as the positive control. Scutellarin inhibited proliferation and induced apoptosis and G2/M cell cycle arrest in the SF-295 cell line in a dose-dependent manner. The effect of scutellarin was similar to but significantly weaker than the effect of 5-FU. The NGS results showed that genes associated with anti-apoptosis signaling pathways were significantly reduced after treatment. The Western blotting results indicated that the expressions of TP63/BIRC3/TRAF1/Bcl-2 were reduced in a dose-dependent manner, as well as the mRNA levels determined by qRT‒PCR. Our original conclusion revealed that scutellarin may inhibit glioma growth in a dose-dependent manner via the p63 signaling pathway which may provide a potential medicine for glioma chemotherapy.

Scutellarin suppresses triple-negative breast cancer metastasis by inhibiting TNFα-induced vascular endothelial barrier breakdown

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with high vascularity and frequent metastasis. Tumor-associated abnormal vasculature was reported to accelerate TNBC metastasis. Scutellarin (SC) is a natural flavonoid with a cardiovascular protective function. In this study, SC reduced TNBC metastasis and alleviated tumor-associated vascular endothelial barrier injury in vivo. SC rescued the tumor necrosis factor-α (TNFα)-induced diminishment of endothelial junctional proteins and dysfunction of the endothelial barrier in vitro. SC reduced the increased transendothelial migration of TNBC cells through a monolayer composed of TNFα-stimulated human mammary microvascular endothelial cells (HMMECs) or human umbilical vein endothelial cells (HUVECs). TNFα induced the nuclear translocation of enhancer of zeste homolog-2 (EZH2), and its chemical inhibitor GSK126 blocked TNFα-induced endothelial barrier disruption and subsequent TNBC transendothelial migration. TNF receptor 2 (TNFR2) is the main receptor by which TNFα regulates endothelial barrier breakdown. Extracellular signal-regulated protein kinase (ERK)1/2 was found to be downstream of TNFα/TNFR2 and upstream of EZH2. Additionally, SC abrogated the TNFR2-ERK1/2-EZH2 signaling axis both in vivo and in vitro. Our results suggest that SC reduced TNBC metastasis by suppressing TNFα-initiated vascular endothelial barrier breakdown through rescuing the reduced expression of junctional proteins by regulating the TNFR2-ERK1/2-EZH2 signaling pathway.

Network pharmacology-based investigation and experimental validation of the mechanism of scutellarin in the treatment of acute myeloid leukemia

Background: It has been demonstrated that scutellarin, a natural flavone compound from Scutellaria lateriflora and Scutellaria barbata, exerts selective cytotoxicity against a range of cancer cells. However, the underlining mechanism of scutellarin on acute myeloid leukemia (AML) remains elusive.

Methods: In this study, the combination of network pharmacology and experimental verification was performed to identify the pharmacological mechanisms of scutellarin for AML therapy. The public databases, such as PharmMapper, UniProt, OMIM, GeneCards, DrugBank and PharmGkb database, were used to sceen the potential targets of scutellarin and AML. The protein-protein interaction (PPI), gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were conducted to uncover the mechanism of scutellarin in the treatment of AML. Finally, the network pharmacological results were further confirmed by in vitro and in vivo experiments.

Results: First and foremost, we totally obtained 289 target genes for scutellarin and 10998 disease targets for AML. 253 overlapping genes were preliminarily considered the potential targets of scutellarin for AML treatment. The results of PPI network analysis, GO analysis and KEGG pathway enrichment demonstrated that the anti-AML effect of scutellarin may focused on MAPK signaling pathway. Furthermore, the cytologic tests suggested that scutellarin can inhibit AML cells proliferation through the mediation of JNK/Caspase-3 pathway. Meanwhile, pretreatment with the JNK inhibitor SP600125 rescued scutellarin-induced apoptosis. Similarly, scutellarin obviously suppressed subcutaneous xenograft growth in nude mice via regulating the JNK/Caspase-3 signaling pathway.

Conclusion: In this study, we integrated network pharmacology-based prediction and experimental validation and revealed the importance of the JNK pathway in scutellarin-mediated AML treatment.

Scutellarin Suppresses Patient-Derived Xenograft Tumor Growth by Directly Targeting AKT in Esophageal Squamous Cell Carcinoma

Scutellarin is a flavonoid compound that is found in Scutellaria barbata It has been reported to exhibit anticancer and anti-inflammation activities. However, the anticancer properties of scutellarin and its molecular targets have not been investigated in esophageal squamous cell carcinoma (ESCC). In the current study, we report that scutellarin is a potential AKT inhibitor that suppresses patient-derived xenograft ESCC tumor growth. To identify possible molecular targets of scutellarin, potential candidate proteins were screened by an in vitro kinase assay and Western blotting. We found that scutellarin directly binds to the AKT1/2 proteins and inhibits activities of AKT1/2 in vitro The AKT protein is activated in ESCC tissues and knockdown of AKT significantly suppresses growth of ESCC cells. Scutellarin significantly inhibits anchorage-dependent and independent cell growth and induces G₂ phase cell-cycle arrest in ESCC cells. The inhibition of cell growth by scutellarin is dependent on the expression of the AKT protein. Notably, scutellarin strongly suppresses patient-derived xenograft ESCC tumor growth in an in vivo mouse model. Taken together, our data suggest that scutellarin is a novel AKT inhibitor that may prevent progression of ESCC.