Ultra-pH-sensitive nanoparticle of gambogenic acid for tumor targeting therapy via anti-vascular strategy plus immunotherapy.

Although the combination of anti-vascular strategy plus immunotherapy has emerged as the optimal first-line treatment of hepatocellular carcinoma, lack of tumor targeting leads to low antitumor efficacy and serious side effect. Here, we report an ultra-pH-sensitive nanoparticle of gambogenic acid (GNA) encapsulated by poly(ethylene glycol)-poly(2-azepane ethyl methacrylate) (PEG-PAEMA) for tumor-targeting combined therapy of anti-vascular strategy plus immunotherapy. PEG-PAEMA-GNA nanoparticle was quite stable at pH 7.4 for 30 d. In contrast, it exerted size shrinkage, charge reversal and the release of GNA at pH 6.7 within 24 h. Moreover, PEG-PAEMA-GNA significantly enhanced the anti-vascular activity, membrane-disruptive capability and pro-apoptosis when pH changed from 7.4 to 6.7. Western blot analysis exhibits that PEG-PAEMA and its GNA nanoparticle facilitated the phosphorylation of STING protein. In vivo assays show that PEG-PAEMA-GNA not only displayed much higher tumor inhibition of 92 % than 37 % of free GNA, but also inhibited tumor vasculature, promoted the maturation of dendritic cells and recruited more cytotoxic t-lymphocytes for sufficient anti-vascular therapy and immunotherapy. All these results demonstrate that PEG-PAEMA-GNA displayed tumor-targeting combined treatment of anti-vascular therapy and immunotherapy. This study offers a simple and novel method for the combination of anti-vascular therapy and immunotherapy with high selectivity towards tumor.

Design, synthesis, and biological evaluation of gambogenic acid derivatives: Unraveling their anti-cancer effects by inducing pyroptosis.

Gambogenic acid (GNA), a caged xanthone derived from Garcinia hanburyi, exhibits a wide range of anti-cancer properties. The caged skeleton of GNA serves as the fundamental pharmacophore responsible for its antitumor effects. However, limited exploration has focused on the structural modifications of GNA. This study endeavors to diversify the structure of GNA and enhance its anti-cancer efficacy. Sulfoximines, recognized as pivotal motifs in medicinal chemistry due to their outstanding properties, have featured in several anti-cancer drugs undergoing clinical trials. Accordingly, a series of 33 GNA derivatives combined with sulfoximines were synthesized and evaluated for their anti-cancer effects against MIAPaCa2, MDA-MB-231, and A549 cells in vitro. The activity screening led to the identification of compound 12k, which exhibited the most potent anti-cancer effect. Mechanistic studies revealed that 12k primarily induced pyroptosis in MIAPaCa2 and MDA-MB-231 cells by activating the caspase-3/gasdermin E (GSDME) pathway. These findings suggested that 12k is a promising drug candidate in cancer therapy and highlighted the potential of sulfoximines as a valuable functional group in drug discovery.

Gambogenic Acid Inhibits Invasion and Metastasis of Melanoma through Regulation of lncRNA MEG3.

Cutaneous melanoma is an aggressive cancer, which is the most common type of melanoma. In our previous studies, gambogenic acid (GNA) inhibited the proliferation and migration of melanoma cells. Maternally expressed gene 3 (MEG3) is a long noncoding RNA (lncRNA) that has been shown to have inhibitory effects in a variety of cancers. However, the mechanisms in melanoma progression need to be further investigated. In the current study, we investigated the inhibitory effect of GNA on melanoma and its molecular mechanism through a series of cell and animal experiments. We found that GNA could improve epithelial mesenchymal transition by up-regulating the expression of the lncRNA MEG3 gene, thereby inhibiting melanoma metastasis in vitro and in vivo.

Gambogenic acid induces cell death in human osteosarcoma through altering iron metabolism, disturbing the redox balance, and activating the P53 signaling pathway.

Osteosarcoma (OS) is the most common primary bone malignancy in children and adolescents with extremely poor prognosis. Gambogenic acid (GNA), one of the major bioactive ingredients isolated from Gamboge, has been shown to possess a multipotent antitumor effect, its activity on OS remains unclear yet. In this study, we found that GNA could trigger multiple cell death modalities, including ferroptosis and apoptosis in human OS cells, reduce the cell viability, inhibit the proliferation and invasiveness. Furthermore, GNA provoked oxidative stress leading to GSH depletion-inducing ROS generation and lipid peroxidation, altered iron metabolism represented by the induction of labile iron, mitochondrial membrane potential decreased, mitochondrial morphological changed, decreased the cell viability. In addition, ferroptosis inhibitors (Fer-1) and apoptosis inhibitors (NAC) can partially reversed GNA' s effects on OS cells. Further investigation showed that GNA augmented the expression of P53, bax, caspase 3 and caspase 9 and decreased the expression of Bcl-2, SLC7A11 and glutathione peroxidase-4 (GPX4). In vivo, GNA was showed to delay tumor growth significantly in axenograft osteosarcoma mouse model. In conclusion, this study reveals that GNA simultaneously triggers ferroptosis and apoptosis in human OS cells by inducing oxidative stress via the P53/SLC7A11/GPX4 axis.

Anti-tumor Effect of Gambogenic Acid and Its Effect on CYP2C and CYP3A after Oral Administration.

Gambogenic acid (GNA), which has a broad spectrum of anti-tumor activity, is considered as a potential anticancer ingredient. In this study, we examined the anti-tumor effect and the effect of GNA on CYP and pregnane X receptor (PXR). In anti-tumor experiments, an A549 cells tumor-bearing nude mice model was established. Tumor weights and volumes were measured. Inhibition ratio (IR) was calculated. In a pharmacokinetic study, after intragastrical administration of GNA in rats, a cocktail method was adopted to evaluate the activities of CYP2C6, 2C11 and 3A1; RT-quantitative PCR (RT-qPCR) and Western blot (WB) assays were applied to evaluate the mRNA and protein expression levels, respectively. Compared with injection, oral administration also can inhibit tumor growth. Moreover, GNA increased the activities of CYP2C11 and CYP3A1 in the high-dose group as well as the mRNA and protein expression levels. The mRNA and protein expression levels of PXR were also slightly induced. Our study suggested that, oral administration of GNA was effective in inhibiting tumor growth in mice and could induced the activities of CYP2C and CYP3A in rats.

Smart anti-vascular nanoagent induces positive feedback loop for self-augmented tumor accumulation.

How to achieve efficient drug accumulation in the tumor with low vascular density is a great challenge but the key to push the limit of anti-vascular therapeutic efficacy. Herein, we report a charge-reversible nanoparticles of gambogenic acid (CRNP-GNA) that would induce the positive feedback loop between increased tumor vascular permeability and improved drug accumulation. This positive feedback loop would remarkably improve tumor vascular permeability for efficient drug accumulation through few residue vessels. As compared to its charge-irreversible analogue in the latter injections, the accumulation in tumor and vascular permeability and retention indexes (VPRI) in CRNP-GNA group respectively boosted from nearly equal to 8.32 and 60 times, while its tumorous microvessel density decreased from nearly equal to only 7%. The self-augmented accumulation consequently amplified the antitumor efficacy via multiple pathways of anti-angiogenesis, vascular disruption and pro-apoptosis, where 5 out of 6 tumors in animal models were completely cured by CRNP-GNA. This work confirms that the underlying positive feedback loop for anti-vascular therapy could be induced by charge-reversible drug delivery nanosystem to achieve efficient and self-augmented drug accumulation even in the tumor with few vessels. It provides a novel strategy to conquer the dilemma between anti-vascular efficacy and drug accumulation.

Gambogenic acid induces apoptosis and autophagy through ROS-mediated endoplasmic reticulum stress via JNK pathway in prostate cancer cells.

Prostate cancer (PCa) is the most common malignant tumor in males, which frequently develops into castration-resistant prostate cancer (CRPC) with limited therapies. Gambogenic acid (GNA), a flavonoids compound isolated from Gamboge, exhibits anti-tumor capacity in various cancers. Our results showed that GNA revealed not only antiproliferative and pro-apoptotic activities but also the induction of autophagy in PCa cells. In addition, autophagy inhibitor chloroquine enhanced the pro-apoptosis effect of GNA. Moreover, the activation of JNK pathway and the induction of apoptosis and autophagy triggered by GNA were attenuated by JNK inhibitor SP600125. We also found that GNA significantly promoted reactive oxygen species (ROS) generation and endoplasmic reticulum (ER) stress. Meanwhile, suppressing ER stress with 4-phenylbutyric acid (4-PBA) markedly blocked the activation of JNK pathway induced by GNA. Further research indicated that ROS scavenger N-acetyl-L-cysteine (NAC) effectively abrogated ER stress and JNK pathway activation induced by GNA. Furthermore, NAC and 4-PBA significantly reversed GNA-triggered apoptosis and autophagy. Finally, GNA remarkably suppressed prostate tumor growth with low toxicity in vivo. In conclusion, the present study revealed that GNA induced apoptosis and autophagy through ROS-mediated ER stress via JNK signaling pathway in PCa cells. Thus, GNA might be a promising therapeutic drug against PCa.

Mechanism of gambogenic acid inhibiting the proliferation of melanoma based on RNA-seq sequencing technology / 中国临床药理学与治疗学

AIM: By analyzing the effect of gambogenic acid (GNA) on the mRNA expression profile of melanoma xenograft model mice, the possible mechanism of GNA in the treatment of melanoma was explored. METHODS: The inhibitory effect of GNA on melanoma cells was studied by measuring the cell survival rate by MTT method in vitro and observing the cell morphology under an inverted microscope. In the in vivo experiment, the effect of GNA on the growth of xenografted tumors in melanoma mice was observed by comparing the results of HE (hematoxylin-eosin) staining and immunohistochemistry (Ki-67), and the tumor weight and tumor weight ratio were recorded. RNA-seq sequencing technology was used to sequence the GNA medium-dose group and the model group, and the screened mRNAs were analyzed by GO and KEGG, and finally the screening results of differentially expressed genes were verified by real-time quantitative fluorescent PCR. RESULTS: After different doses of GNA acted on the melanoma mouse model, a large area of necrosis occurred in the tumor tissue of the model mouse, and the tumor growth was significantly inhibited. A total of 36 differentially expressed mRNAs were identified by mRNA sequencing, of which 30 were up-regulated and 6 were down-regulated. The possible functions of the mRNAs were predicted according to the genomic adjacency analyzed by GO and KEGG. The expression of the selected differential mRNAs was further verified by real-time quantitative PCR technology. The results showed that the mRNA expressions of Cidec, Ces1d, Mylk4, and Igkv9-123 were up-regulated, and the mRNA expressions of Ryr3 and Hapln1 were down-regulated. CONCLUSION: GNA can inhibit the proliferation of melanoma cells in vitro and in vivo, and its mechanism is related to the regulation of cytokine-cytokine receptor interaction, NF-κB, MAPK, and other pathways of mRNA expression.

Gambogenic acid alleviates kidney fibrosis via epigenetic inhibition of EZH2 to regulate Smad7-dependent mechanism.

BACKGROUND: Epigenetics regulating gene expression plays important role in kidney fibrosis. Natural products originating from diverse sources including plants and microorganisms are capable to influence epigenetic modifications. Gambogenic acid (GNA) is a caged xanthone extracted from gamboge resin, exudation of Garcinia hanburyi Hook.f., and the effect of GNA on kidney fibrosis with its underlying mechanism on epigenetics remains unknown. PURPOSE: This study aimed to explore the role of GNA against kidney fibrogenesis by histone methylation mediating gene expression. METHODS: Two experimental mice of unilateral ureteral obstruction (UUO) and folic acid (FA) were given two dosages of GNA (3 and 6 mg/kg/d). TGF-ß1 was used to stimulate mouse tubular epithelial (TCMK-1) cells and siRNAs were transfected to verify the underlying mechanisms of GNA. Histological changes were evaluated by HE, MASSON stainings, immunohistochemistry and immunofluorescence. Western blot and qPCR were used to measure protein/gene transcription levels. RESULTS: GNA dose-dependently alleviated UUO-induced kidney fibrosis and FA-induced kidney early fibrosis, indicated by the pathology and fibrotic factor changes (α-SMA, collagen I, collagen VI, and fibronectin). Mechanically, GNA reduced enhancer of zeste homolog 2 (EZH2) and H3K27me3, promoted Smad7 transcription, and inhibited TGF-ß/Smad3 fibrotic signaling in injured kidneys. Moreover, with TGF-ß1-induced EZH2 increasing, GNA suppressed α-SMA, fibronectin and collagen levels in tubular epithelial TCMK-1 cells. Although partially decreasing EZH2, GNA did not influence fibrotic signaling in Smad7 siRNA-transfected TCMK-1 cells. CONCLUSION: Epigenetic inhibition of EZH2 by GNA ameliorated kidney fibrogenesis via regulating Smad7-meidated TGF-ß/Smad3 signaling.

Gambogenic Acid Inhibits Basal Autophagy of Drug-Resistant Hepatoma Cells and Improves Its Sensitivity to Adriamycin.

Gambogenic acid (GNA) is extracted from plant Gamboge, has a wide range of anti-tumor effects. In this paper, we study the inhibitory effect of GNA on the BEL-7402/ADM of hepatoma resistant cell lines and further study the mechanism of action. Cell viability test represented that GNA could improve the sensitivity of hepatoma drug-resistant cell line BEL-7402/ADM to Adriamycin (ADM), and further study by 4',6-diamidino-2-phenylindole (DAPI) staining and flow cytometry found that GNA could improve the effect of ADM on promoting apoptosis in BEL-7402/ADM cells, and the activation of apoptosis-related protein was significantly increased, and the ratio of Bax to Bcl-2 was significantly increased. Monodansylcadaverine staining and transmission electron microscopy showed that the basal autophagy level of BEL-7402/ADM cells was higher than that of BEL-7402 cells. Further detection of protein expression found that the intracellular LC3-II to LC3-I ratio and Beclin 1 protein expression increased in the combination of GNA and ADM, but the protein level of p62 increased significantly. GNA inhibit protective autophagy in BEL-7402/ADM cells and promote the role of ADM in inducing apoptosis, thereby increasing ADM sensitivity to BEL-7402/ADM cells, and the effect of GNA inhibition of autophagy may be achieved by inhibiting the degradation of autophagosomes.

Gambogenic Acid Induces Endoplasmic Reticulum Stress in Colorectal Cancer via the Aurora A Pathway.

Colorectal cancer (CRC) is one of the most common malignancies in the world and has a poor prognosis. In the present research, gambogenic acid (GNA), isolated from the traditional Chinese medicine gamboge, markedly induced apoptosis and inhibited the proliferation of CRC in vitro and in vivo. Furthermore, GNA triggered endoplasmic reticulum (ER) stress, which subsequently activated inositol-requiring enzyme (IRE) 1α and the eukaryotic translation initiation factor (eIF) 2α pathway. Pretreatment with salubrinal (an eIF2α inhibitor) rescued GNA-induced cell death. Furthermore, GNA downregulated the expression of Aurora A. The Aurora A inhibitor alisertib decreased ER stress. In human colorectal adenocarcinoma tissue, Aurora A was upregulated compared to normal colorectal epithelial nuclei. Furthermore, GNA ameliorated mouse colitis-associated cancer models. Our findings demonstrated that GNA significantly inhibited the proliferation of CRC through activation of ER stress by regulating Aurora A, which indicates the potential of GNA for preventing the progression of CRC.

Gambogic acid and gambogenic acid induce a thiol-dependent heat shock response and disrupt the interaction between HSP90 and HSF1 or HSF2.

Cancer cells rely on heat shock proteins (HSPs) for growth and survival. Especially HSP90 has multiple client proteins and plays a critical role in malignant transformation, and therefore different types of HSP90 inhibitors are being developed. The bioactive natural compound gambogic acid (GB) is a prenylated xanthone with antitumor activity, and it has been proposed to function as an HSP90 inhibitor. However, there are contradicting reports whether GB induces a heat shock response (HSR), which is cytoprotective for cancer cells and therefore a potentially problematic feature for an anticancer drug. In this study, we show that GB and a structurally related compound, called gambogenic acid (GBA), induce a robust HSR, in a thiol-dependent manner. Using heat shock factor 1 (HSF1) or HSF2 knockout cells, we show that the GB or GBA-induced HSR is HSF1-dependent. Intriguingly, using closed form ATP-bound HSP90 mutants that can be co-precipitated with HSF1, a known facilitator of cancer, we show that also endogenous HSF2 co-precipitates with HSP90. GB and GBA treatment disrupt the interaction between HSP90 and HSF1 and HSP90 and HSF2. Our study implies that these compounds should be used cautiously if developed for cancer therapies, since GB and its derivative GBA are strong inducers of the HSR, in multiple cell types, by involving the dissociation of a HSP90-HSF1/HSF2 complex.

Oral Delivery of Gambogenic Acid by Functional Polydopamine Nanoparticles for Targeted Tumor Therapy.

To enhance the water solubility, oral bioavailability, and tumor targeting of gambogenic acid (GNA), polydopamine nanoparticles (PDA NPs) were prepared to encapsulate and stabilize GNA surface modified by folic acid (FA) and then coated with sodium alginate (GNA@PDA-FA SA NPs) to achieve an antitumor effect by oral administration. GNA@PDA-FA SA NPs exhibited in vitro pH-sensitive release behavior. In vitro cell studies manifested that GNA@PDA-FA NPs had higher cytotoxicity to 4T1 cells compared with raw GNA (IC50 = 2.58 µM vs 7.57 µM). After being modified with FA, GNA@PDA-FA NPs were taken up easily by 4T1 cells. In vivo studies demonstrated that the area under the curve (AUC0→∞) of the plasma drug concentration-time of GNA@PDA-FA SA NPs was 2.97-fold higher than that of raw GNA, along with improving drug distribution in the liver, lung, and kidney tissues. In vivo anti-tumor experiments, GNA@PDA-FA SA NPs significantly inhibited the growth of breast tumors in the 4T1 xenograft breast cancer model via oral administration without obvious toxicity on major organs. Our studies indicated that the GNA@PDA-FA SA NPs modified with FA and coated with SA were a promising drug delivery system for targeting tumor therapy via oral administration.

Scar-reducing effects of gambogenic acid on skin wounds in rabbit ears.

Hypertrophic scar (HS) is a dermal fibroproliferative disease that often occurs following abnormal wound healing. To date, there is no satisfied treatment strategies for improvement of scar formation with few side effects. The effects of gambogenic acid (GNA) on scar hypertrophy has not been studied previously. The present study was undertaken to find out the scar-reducing effects of GNA (0.48, 0.96 or 1.92 mg/ml) on skin wounds in rabbit ears. Scar evaluation index (SEI), collagen I (Col1) and collagen III (Col3), microvascular density (MVD), CD4+T cells and macrophages, vascular endothelial growth factor receptor 2 (VEGFR2), fibroblast growth factor receptor 1 (FGFR1), phospho-VEGFR 2 (p-VEGFR2) and p-FGFR1, interleukin (IL)-1ß, IL-6, IL-10 and tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-ß1 and connective tissue growth factor (CTGF) in scar tissue were detected using various methods, respectively. Our data showed that GNA significantly reduced SEI, and the expression of Col1 and Col3 in scar tissue in a concentration-dependent manner. Also, it decreased MVD, the infiltration of CD4+T cells and macrophages, and the levels of VEGFR2, p-VEGFR2, FGFR1, p-FGFR1, TGF-ß1, CTGF, IL-1ß, IL-6, TNF-α, in addition to upregulated IL-10 in scar tissue. As a result, this study revealed that GNA reduced HS formation, which was associated with the inhibition of neoangiogenesis, local inflammatory response and growth factor expression in scar tissue during wound healing. These findings suggested that GNA may be considered as a preventive and therapeutic candidate for HS.

Gambogenic acid induces Noxa-mediated apoptosis in colorectal cancer through ROS-dependent activation of IRE1α/JNK.

BACKGROUND: Gambogenic acid (GNA), an active component of Garcinia hanburyi Hook.f. (Clusiaceae) (common name gamboge), exerts anti-inflammatory and antitumor properties. However, the underlying mechanism of GNA in colorectal cancer (CRC) is still not well understood. PURPOSE: This study aimed to investigate the antitumor effects and mechanisms of GNA on CRC in vitro and in vivo. METHODS: Cell viability, colony formation and cell apoptosis assays were performed to determine the antitumor effects of GNA. qRT-PCR and Western blotting were performed to evaluate the expression of genes or proteins affected by GNA in vitro and in vivo. HCT116 colon cancer xenografts and the APCmin/+ mice model were used to confirm the antitumor effects of GNA on CRC in vivo. RESULTS: GNA induced Noxa-mediated apoptosis by inducing reactive oxygen species (ROS) generation and c-Jun N-terminal kinase (JNK) activation. Moreover, GNA triggered endoplasmic reticulum (ER) stress, which subsequently activated inositol-requiring enzyme-1α (IRE1α) leading to JNK phosphorylation. ROS scavenger attenuated GNA-induced IRE1α activation and JNK phosphorylation. Knockdown of IRE1α also prevented GNA-induced JNK phosphorylation. In vivo, GNA suppressed tumor growth and progression in HCT116 colon cancer xenografts and the APCmin/+ mices model. CONCLUSION: These findings revealed that GNA induced Noxa-mediated apoptosis by activating the ROS/IRE1α/JNK signaling pathway in CRC both in vitro and in vivo. GNA is therefore a promising antitumor agent for CRC treatment.

In vitro/in vivo evaluation of pH-sensitive Gambogenic acid loaded Zein nanoparticles with polydopamine coating.

As one of the active pharmaceutical ingredients in Gamboge, Gambogenic acid (GNA) has shown diverse anti-tumor activities. To reduce the vascular irritation of GNA and improve its water solubility, tumor targeting, and bioavailability, GNA loaded Zein nanoparticles (GNA@Zein NPs) was further coated by polydopamine (PDA) to develop GNA@Zein-PDA NPs by anti-solvent precipitation and surface modification. The results showed that particle size and Zeta potential of GNA@Zein-PDA NPs were about 310 nm and -40.8 mV with core-shell morphology confirmed by TEM. GNA@Zein-PDA NPs increased the water solubility of GNA by more than 700 times and showed pH-sensitive release behavior in PBS with pH 6.86. In vitro cytotoxicity tests showed that GNA@Zein-PDA NPs had higher inhibitory activity on HepG2 cells than free GNA, and their IC50 were 1.59 µg/mL and 9.89 µg/mL, respectively. Additionally, the hemolysis and vascular irritation assay showed that GNA@Zein-PDA NPs had good cytocompatibility and reduced the irritation of GNA to blood vessels. Moreover, the in vivo pharmacokinetic experiments exhibited that the Cmax and AUC0-t of GNA@Zein-PDA NPs were significantly improved approximately by 2.09-fold and 3.48-fold over that of GNA, respectively. In conclusion, GNA@Zein-PDA NPs solve many defects of GNA and provide a tumor-targeting drug delivery for GNA.

Gambogenic acid suppresses bladder cancer cells growth and metastasis by regulating NF-κB signaling.

BACKGROUND: Gambogenic acid (GNA) is one of the main active components of Gamboge, and its anticancer role has been reported in some cancers. The study was to investigate the inhibitory effects of GNA on the proliferation and metastasis of bladder cancer (BC) cells and its potential regulatory mechanisms. MATERIALS AND METHODS: BC cell lines (BIU-87 cells, T24 cells, and J82 cells) were treated with different doses of GNA for different time, and then the effects of GNA on BC cell were examined in vitro using CCK-8 assay, apoptosis assays, and Transwell tests. NF-κB signaling activity was detected by the NF-κB p65 luciferase reporter assay. Western blot was used to detect the expressions of cIAP2, XIAP, Survivin, and p65. RESULTS: GNA inhibited the viability of BC cells in vitro in a dose- and time-dependent manner and facilitated apoptosis of BC cells. Moreover, GNA could remarkably impede the migration and invasion abilities of BC cells. In terms of mechanism, GNA administration reduced the activity of NF-κB signaling and down-regulated the expressions of p65, survivin, XIAP, and cIAP2. CONCLUSION: GNA blocks the growth and metastasis of BC cells via inhibiting the NF-κB signal transduction pathway.

Gambogenic acid induces ferroptosis in melanoma cells undergoing epithelial-to-mesenchymal transition.

Melanoma is characterized by high malignancy and early onset of metastasis. Epithelial-to-mesenchymal transition (EMT) is an early event during tumor metastasis. Tumor cells that develop EMT can escape apoptosis, but they are vulnerable to ferroptosis inducers. Gambogenic acid (GNA), a xanthone found in Gamboge, has cytotoxic effects in highly invasive melanoma cells. This study investigated the anti-melanoma effect and mechanism of action of GNA in TGF-ß1-induced EMT melanoma cells. We found that GNA significantly inhibited the invasion, migration and EMT in melanoma cells, and these cells exhibited small mitochondrial wrinkling (an important feature of ferroptosis). An iron chelator, but not an apoptosis inhibitor or a necrosis inhibitor, abolished the inhibitory effects of GNA on proliferation, invasion and migration of TGF-ß1-stimulated melanoma cells. GNA upregulated the expression of p53, solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) in the model cells, contributing to the mechanisms underlying GNA-induced ferroptosis. Collectively, our findings suggest that GNA induces ferroptosis in TGF-ß1-stimulated melanoma cells via the p53/SLC7A11/GPX4 signaling pathway.

Folic acid-modified nonionic surfactant vesicles for gambogenic acid targeting: Preparation, characterization, and in vitro and in vivo evaluation.

The aim of present study was to develop folic acid (FA)-modified nonionic surfactant vesicles (NISVs, niosomes) as carrier systems for targeted delivery of gambogenic acid (GNA). The FA-GNA-NISVs exhibited a mean particle size of 180.77 ± 2.41 nm with a narrow poly dispersion index of 0.147 ± 0.08 determined by dynamic light scattering. Transmission electron microscopy also revealed that the FA-GNA-NISVs were spherical with double-layer structure. Entrapment efficiency (EE%) and zeta potential of the optimal FA-GNA-NISVs were 87.84 ± 1.06% and -37.33 ± 0.33 mV, respectively. Differential scanning calorimetry demonstrated that the GNA was in a molecular or amorphous state inside the FA-NISVs in vitro release profiles suggested that FA-GNA-NISVs could release GNA at a sustained manner, and less than 60% of GNA was released from the FA-NISVs within 12 hours of dialysis. in vivo pharmacokinetic results illustrated that FA-GNA-NISVs had considerably higher Cmax , area under curve (AUC0 - t ) and accumulation in lung. The cell proliferation study shown that the FA-GNA-NISVs significantly enhanced the in vitro cytotoxicity against A549 cells. Flow cytometry and fluorescence microscopy further demonstrated that the FA-GNA-NISVs increased apoptosis compared with nonmodified GNA-NISVs and free GNA. Moreover, FA-GNA-NISVs induced A549 cell apoptosis in a dose-dependent manner. In addition, cellular uptake assays showed a higher uptake of FA-GNA-NISVs than GNA-NISVs as well as free GNA. Taken together, it could be concluded that FA-GNA-NISVs were proposed as a novel targeting carriers for efficient delivering of GNA to cancers cells.

Gambogenic acid exerts anticancer effects in cisplatin­resistant non­small cell lung cancer cells.

Non­small cell lung cancer (NSCLC) is the most common type of lung cancer and the most common cause of mortality in patients with lung cancer. The efficacy of cisplatin­based chemotherapy in NSCLC is limited by drug resistance, therefore, the development of novel anticancer agents is required to overcome cisplatin resistance. The present study investigated the anticancer activity of gambogenic acid (GNA), derived from gamboge, in the cisplatin­resistant NSCLC cell line A549/Cis. GNA was revealed to have a potent inhibitory effect on cell growth in A549/Cis cells by blocking the cell cycle and inducing apoptosis. The investigation of the molecular mechanisms identified that GNA arrested the cell cycle at the G1 phase through the downregulation of cyclin Ds, cyclin dependent kinase (CDK)4 and CDK6, and the upregulation of p53 and p21. In addition, GNA induced apoptosis by increasing the activation of caspase 3 and caspase 7, in addition to the cleavage of poly(ADP­ribose) polymerase. The results of the present study supported the potential application of GNA in cisplatin­resistant NSCLC.