Gambogenic acid induces cell growth inhibition, cell cycle arrest and metastasis inhibition in choroidal melanoma in a dose-dependent manner

Unveiling Gambogenic Acid as a Promising Antitumor Compound: A Review

Gambogenic acid is a derivative of gambogic acid, a polyprenylated xanthone isolated from Garcinia hanburyi. Compared with the more widely studied gambogic acid, gambogenic acid has demonstrated advantages such as a more potent antitumor effect and less systemic toxicity than gambogic acid according to early investigations. Therefore, the present review summarizes the effectiveness and mechanisms of gambogenic acid in different cancers and highlights the mechanisms of action. In addition, drug delivery systems to improve the bioavailability of gambogenic acid and its pharmacokinetic profile are included. Gambogenic acid has been applied to treat a wide range of cancers, such as lung, liver, colorectal, breast, gastric, bladder, and prostate cancers. Gambogenic acid exerts its antitumor effects as a novel class of enhancer of zeste homolog 2 inhibitors. It prevents cancer cell proliferation by inducing apoptosis, ferroptosis, and necroptosis and controlling the cell cycle as well as autophagy. Gambogenic acid also hinders tumor cell invasion and metastasis by downregulating metastasis-related proteins. Moreover, gambogenic acid increases the sensitivity of cancer cells to chemotherapy and has shown effects on multidrug resistance in malignancy. This review adds insights for the prevention and treatment of cancers using gambogenic acid.

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 antagonizes the expression and effects of long non-coding RNA NEAT1 and triggers autophagy and ferroptosis in melanoma

In this study, we investigated the molecular mechanism underlying melanoma proliferation, with the aim to discover effective interventions which may markedly improve clinical prognosis. The results showed that gambogenic acid (GNA) could inhibit the proliferation of melanoma cells in vivo (C57BL/6 mice) and in vitro. Long non-coding RNA sequencing was used to identify the most significant long non-coding RNA, i.e., nuclear enriched abundant transcript 1 (NEAT1). NEAT1 was is up-regulated in melanoma, which was found to closely relate to cell proliferation. Melanoma cell lines either over-expressing NEAT1 or with NEAT1 knockdown was established through cloning experiments. A model of transplanted tumors was established to verify the inhibitory effect of GNA on the proliferation of melanoma cells in vitro and in vivo by downregulating NEAT1. Downregulation of NEAT1-induced ferroptosis and autophagy was demonstrated by detecting the effects of NEAT1 overexpressed and downregulated melanoma cell lines and melanoma transplantation model mice. Mechanistically, downregulation of NEAT1 can weaken the direct binding of Slc7a11, indirectly leading to inhibiting GPX-4 activity and subsequent ferroptosis, while, mediating the AMPK/mTOR signal axis-induced autophagy. The levels of Furthermore, NEAT1 decrease under the treatment of Gambogenic acid (GNA), a promising natural anticancer compound, while NEAT1 overexpression suppresses GNA inhibition on cell vitality and eliminates GNA-induced melanoma cell ferroptosis and autophagy.

Degradation strategy of cyclin D1 in cancer cells and the potential clinical application

Cyclin D1 has been reported to be upregulated in several solid and hematologic tumors, promoting cancer progression. Thus, decreasing cyclin D1 by degradation could be a promising target strategy for cancer therapy. This mini review summarizes the roles of cyclin D1 in tumorigenesis and progression and its degradation strategies. Besides, we proposed an exploration of the degradation of cyclin D1 by FBX4, an F box protein belonging to the E3 ligase SKP-CUL-F-box (SCF) complex, which mediates substrate ubiquitination, as well as a postulate about the concrete combination mode of FBX4 and cyclin D1. Furthermore, we proposed a possible photodynamic therapy strategythat is based on the above concrete combination mode for treating superficial cancer.

miR-876-3p suppresses the progression of colon cancer and correlates the prognosis of patients

BACKGROUND

miR-876-3p has been identified to be downregulated in colon cancer, implying the potential biological function in the progression and prognosis of colon cancer. The clinical significance and the biological function of miR-876-3p were investigated in this study to assess the potential of miR-876-3p in acting as a novel biomarker of the progression of colon cancer.

METHODS

The expression of miR-876-3p in colon cancer was evaluated by RT-qPCR. The clinical significance of miR-876-3p was assessed by associated its expression level with the clinical features and prognosis of patients. The biological function of miR-876-3p was estimated by the CCK8 and Transwell assay in vitro.

RESULTS

The significant downregulation of miR-876-3p was observed in colon cancer tissues and cells, which was closely associated with the lymph node metastasis status, TNM stage, and the perineural invasion of patients. miR-876-3p served as an independent indicator that was negatively associated with the prognosis of patients. In colon cancer cells, miR-876-3p showed significant inhibitory effects on cell proliferation, migration, and invasion, indicating its tumor suppressor role in the progression of colon cancer.

CONCLUSION

miR-876-3p might be involved in colon cancer development, which provides a potential therapeutic target for colon cancer treatment.

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-β1-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-β1-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-β1-stimulated melanoma cells via the p53/SLC7A11/GPX4 signaling pathway.

An update on the implications of cyclin D1 in melanomas

Cyclin D1 is a protein encoded by the CCND1 gene, located on 11q13 chromosome, which is a key component of the physiological regulation of the cell cycle. CCND1/cyclin D1 is upregulated in several types of human tumors including melanoma and is currently classified as an oncogene that promotes uncontrolled cell proliferation. Despite the demonstrated importance of CCND1/cyclin D1 as a central oncogene in several types of human tumors, its knowledge in melanoma is still limited. This review examines data published on upregulation of the CCND1 gene and cyclin D1 protein in the melanoma setting, focusing on the pathways and molecular mechanisms involved in the activation of the gene and on the clinical and therapeutic implications.

Preparation and preliminary pharmacokinetics study of GNA-loaded zein nanoparticles

OBJECTIVES

Gambogenic acid (GNA), one of the main active ingredients isolated from Garcinia cambogia, has shown diverse antitumour activities. However, short biological half-life and low oral bioavailability severely limit its clinical application. Here, we developed GNA-loaded zein nanoparticles (GNA-ZN-NPs) based on phospholipid complex and zein nanoparticles to prolong the circulation time and enhance oral bioavailability of GNA.

METHODS

The physicochemical properties of GNA-ZN-NP were characterized in details. The in vitro release profile, in vivo pharmacokinetic experiments and tissue distribution of GNA-ZN-NPs were also evaluated.

KEY FINDINGS

The particle size, PDI and encapsulation efficiency of GNA-ZN-NPs were 102.90 nm, 0.027 and 76.35 ± 0.64%, respectively. The results of SEM, FTIR, DSC and XRD demonstrated that GNA-ZN-NPs were prepared successfully. The in vitro dissolution of GNA-ZN-NPs exhibited controlled release compared with raw GNA solution. The pharmacokinetic study showed that the AUC of GNA-ZN-NPs was significantly increased, and the t_1/2 and MRT values of GNA-ZN-NPs were 3.21-fold and 2.19-fold higher than that of GNA solution. Tissue distribution results illustrated that GNA-ZN-NPs showed hepatic-targeting properties.

CONCLUSION

GNA-ZN-NPs significantly enhanced the oral bioavailability and prolonged half-life of GNA, providing a promising oral drug delivery system to improve in vivo pharmacokinetic behaviour of GNA.

Gambogenic acid inhibits the proliferation of small‑cell lung cancer cells by arresting the cell cycle and inducing apoptosis

Gambogenic acid (GNA), which is an important active compound present in gamboge, exerts anticancer activity in various types of tumor cells. However, the effect of GNA on small‑cell lung cancer (SCLC) cell lines and the underlying mechanism involved still remain unclear. In the present study, GNA inhibited the proliferation and cell cycle progression of SCLC cells. GNA also promoted the apoptosis of SCLC cells in a dose‑dependent manner, which is associated with modulating the levels of proteins involved in apoptosis pathways in NCI‑H446 and NCI‑H1688 cells. The results demonstrated that GNA increased the level of cleaved caspase‑3, ‑8 and ‑9, and Bax but decreased the expression of anti‑apoptotic protein, Bcl‑2. Furthermore, similar results were obtained in a mouse tumor xenograft model. Additionally, GNA exhibit low toxicity in tissues when administered to mice in the SCLC xenograft models. Collectively, our findings demonstrated that GNA significantly inhibited the proliferation of SCLC cells and promoted cell apoptosis via cell cycle arrest and induction of apoptosis.

Oridonin inhibits migration, invasion, adhesion and TGF-β1-induced epithelial-mesenchymal transition of melanoma cells by inhibiting the activity of PI3K/Akt/GSK-3β signaling pathway

Epithelial-mesenchymal transition (EMT) has been reported to play pivotal roles in tumor invasion and metastasis. Inhibition of EMT may exert beneficial effects in regulating metastasis. Oridonin (ORI), an active diterpenoid compound isolated from Rabdosia rubescens, was found to be a potent anti-metastatic agent. However, the possible involvement of ORI in the EMT in malignant melanoma is unclear. The present study found that ORI inhibited cell migration, invasion, and adhesion in A375 and B16-F10 melanoma cells. The transforming growth factor-β1 (TGF-β1)-induced EMT was also inhibited in ORI-treated cells, as reflected in the upregulation of E-cadherin, and downregulation of vimentin and Snail. Similar results were observed in A375 and B16-F10 melanoma cells treated with ORI. Furthermore, pre-treatment with ORI blocked the TGF-β1-induced phosphoinositide 3-kinase (PI3K)/AKT serine/threonine kinase (Akt)/glycogen synthase kinase (GSK)-3β signaling pathway activation. These effects mimicked PI3 kinase inhibitor LY294002 treatment. ORI interfered with the PI3K/Akt/GSK-3β pathway, and reversed TGF-β1-induced EMT, which suppressed the invasion and metastasis of melanoma cells. Taken together, the present study demonstrated that ORI inhibits melanoma cells migration, invasion, and adhesion and TGF-β1-induced EMT through the PI3K/Akt/GSK-3β signaling pathway. These findings suggest that ORI is a promising anti-metastasis agent for melanoma.