β-Mangostin inhibits the metastatic power of cervical cancer cells attributing to suppression of JNK2/AP-1/Snail cascade

Alpha-mangostin alleviate renal interstitial fibrosis via suppression of TGF-β1/Smad/ERK signaling axis in vitro and in vivo

α-mangostin (α-MG), a natural derivative of coumarin, exhibits anti-inflammatory, antioxidant and anti-fibrotic effects. This study aimed to determine the effect of α-MG treatment in mediating the process of renal interstitial fibrosis. We found that α-MG could alleviate tubule-interstitial damage and decrease fibrotic (α-smooth muscle actin [α-SMA], fibronectin, and collagen I), and epithelial-mesenchymal transition (EMT) protein (N-cadherin, Snail, Slug, TGF-β1 and vimentin) expression in unilateral ureteral obstruction (UUO) mice with chronic kidney disease. α-MG significantly decreased motility as well as inhibited expression of fibrotic- and EMT-related proteins in TGF-β1-induced HK2 cells. To clarify the molecular mechanisms of α-MG in reducing renal interstitial fibrosis, we used a MEK inhibitor (U0126) or Smad inhibitor (SB431542) cotreatment with α-MG. This is the first study is to demonstrate the antifibrotic effects of α-MG by targeting the TGF-β1/ERK/Smad-mediated EMT signaling pathway, is even more effective against renal interstitial fibrosis.

Development and Assessment of 1,5-Diarylpyrazole/Oxime Hybrids Targeting EGFR and JNK-2 as Antiproliferative Agents: A Comprehensive Study through Synthesis, Molecular Docking, and Evaluation

New 1,5-diarylpyrazole oxime hybrid derivatives (scaffolds A and B) were designed, synthesized, and then their purity was verified using a variety of spectroscopic methods. A panel of five cancer cell lines known to express EGFR and JNK-2, including human colorectal adenocarcinoma cell line DLD-1, human cervical cancer cell line Hela, human leukemia cell line K562, human pancreatic cell line SUIT-2, and human hepatocellular carcinoma cell line HepG2, were used to biologically evaluate for their in vitro cytotoxicity for all the synthesized compounds 7a-j, 8a-j, 9a-c, and 10a-c. The oxime containing compounds 8a-j and 10a-c were more active as antiproliferative agents than their non-oxime congeners 7a-j and 9a-c. Compounds 8d, 8g, 8i, and 10c inhibited EGFR with IC50 values ranging from 8 to 21 µM when compared with sorafenib. Compound 8i inhibited JNK-2 as effectively as sorafenib, with an IC50 of 1.0 µM. Furthermore, compound 8g showed cell cycle arrest at the G2/M phase in the cell cycle analysis of the Hela cell line, whereas compound 8i showed combined S phase and G2 phase arrest. According to docking studies, oxime hybrid compounds 8d, 8g, 8i, and 10c exhibited binding free energies ranging from -12.98 to 32.30 kcal/mol at the EGFR binding site whereas compounds 8d and 8i had binding free energies ranging from -9.16 to -12.00 kcal/mol at the JNK-2 binding site.

Bioactivities of β-mangostin and its new glycoside derivatives synthesized by enzymatic reactions

Beta-mangostin is a xanthone commonly found in the genus Garcinia. Unlike α-mangostin, to date, there have only been a few studies on the biological activity and derivatization of β-mangostin. In this study, two novel glycosylated derivatives of β-mangostin were successfully synthesized via a one-pot enzymatic reaction. These derivatives were characterized as β-mangostin 6-O-β-d-glucopyranoside and β-mangostin 6-O-β-d-2-deoxyglucopyranoside by TOF ESI/MS and 1H and 13C NMR analyses. Beta-mangostin showed cytotoxicity against KB, MCF7, A549 and HepG2 cancer cell lines, with IC50 values ranging from 15.42 to 21.13 µM. The acetylcholinesterase and α-glucosidase inhibitory activities of β-mangostin were determined with IC50 values of 2.17 and 27.61 µM, respectively. A strong anti-microbial activity of β-mangostin against Gram-positive strains (Bacillus subtilis, Lactobacillus fermentum and Staphylococcus aureus) was observed, with IC50 values of 0.16, 0.18 and 1.24 µg ml-1, respectively. Beta-mangostin showed weaker activity against Gram-negative strains (Salmonella enterica, Escherichia coli and Pseudomonas aeruginosa) as well as Candida albicans fungus, with IC50 and MIC values greater than the tested concentration (greater than 32 µg ml-1). The new derivatives of β-mangostin showed weaker activities than those of β-mangostin, demonstrating the important role of the hydroxyl group at C-6 of β-mangostin in its bioactivity.

α-Mangostin induces oxidative damage, mitochondrial dysfunction, and apoptosis in a triple-negative breast cancer model

Triple-negative breast cancer (TNBC) does not express estrogen receptor, progesterone receptor, and human epidermal growth factor receptor; therefore, TNBC lacks targeted therapy, and chemotherapy is the only available treatment for this illness but causes side effects. A putative strategy for the treatment of TNBC could be the use of the polyphenols such as α-Mangostin (α-M), which has shown anticancerogenic effects in different cancer models and can modulate the inflammatory and prooxidant state in several pathological models. The redox state, oxidative stress (OS), and oxidative damage are highly related to cancer development and its treatment. Thus, this study aimed to evaluate the effects of α-M on redox state, mitochondrial metabolism, and apoptosis in 4T1 mammary carcinoma cells. We found that α-M decreases both protein levels and enzymatic activity of catalase, and increases reactive oxygen species, oxidized proteins and glutathione disulfide, which demonstrates that α-M induces oxidative damage. We also found that α-M promotes mitochondrial dysfunction by abating basal respiration, the respiration ligated to oxidative phosphorylation (OXPHOS), and the rate control of whole 4T1 cells. Additionally, α-M also decreases the levels of OXPHOS subunits of mitochondrial complexes I, II, III, and adenosine triphosphate synthase, the activity of mitochondrial complex I as well as the levels of peroxisome proliferator-activated receptor-gamma co-activator 1α, showing a mitochondrial mass reduction. Then, oxidative damage and mitochondrial dysfunction induced by α-M induce apoptosis of 4T1 cells, which is evidenced by B cell lymphoma 2 decrease and caspase 3 cleavage. Taken together, our results suggest that α-M induces OS and mitochondrial dysfunction, resulting in 4T1 cell death through apoptotic mechanisms.

Melatonin acts synergistically with pazopanib against renal cell carcinoma cells through p38 mitogen-activated protein kinase-mediated mitochondrial and autophagic apoptosis

BACKGROUND

Mounting evidence indicates that melatonin has possible activity against different tumors. Pazopanib is an anticancer drug used to treat renal cell carcinoma (RCC). This study tested the anticancer activity of melatonin combined with pazopanib on RCC cells and explored the underlying mechanistic pathways of its action.

METHODS

The 786-O and A-498 human RCC cell lines were used as cell models. Cell viability and tumorigenesis were detected with the MTT and colony formation assays, respectively. Apoptosis and autophagy were assessed using TUNEL, annexin V/propidium iodide, and acridine orange staining with flow cytometry. The expression of cellular signaling proteins was investigated with western blotting. The in vivo growth of tumors derived from RCC cells was evaluated using a xenograft mouse model.

RESULTS

Together, melatonin and pazopanib reduced cell viability and colony formation and promoted the apoptosis of RCC cells. Furthermore, the combination of melatonin and pazopanib triggered more mitochondrial, caspase-mediated, and LC3-II-mediated autophagic apoptosis than melatonin or pazopanib alone. The combination also induced higher activation of the p38 mitogen-activated protein kinase (p38MAPK) in the promotion of autophagy and apoptosis by RCC cells than melatonin or pazopanib alone. Finally, tumor xenograft experiments confirmed that melatonin and pazopanib cooperatively inhibited RCC growth in vivo and predicted a possible interaction between melatonin/pazopanib and LC3-II.

CONCLUSION

The combination of melatonin and pazopanib inhibits the growth of RCC cells by inducing p38MAPK-mediated mitochondrial and autophagic apoptosis. Therefore, melatonin might be a potential adjuvant that could act synergistically with pazopanib for RCC treatment.

Asiatic acid exhibits antimetastatic activity in human prostate cancer cells by modulating the MZF-1/Elk-1/Snail signaling axis

Prostate cancer metastasis is associated with poor prognosis and is difficult to treat clinically. Numerous studies have shown that Asiatic Acid (AA) has antibacterial, anti-inflammatory, and antioxidant effects. However, the effect of AA on prostate cancer metastasis is still unclear. This purpose of this study is to investigate the effect of AA on prostate cancer metastasis and to better understand its molecular mechanisms of action. Our results indicate that AA ≤ 30 μM did not influence cell viability and cell cycle distribution in PC3, 22Rv1 and DU145 cells. AA inhibited the migratory and invasive capabilities of three prostate cancer cells to be due to its effects on Snail, but did not have activity on Slug. We observed that AA inhibited the Myeloid zinc finger 1 (MZF-1) and ETS Like-1 (Elk-1) protein interaction and affected the complex's binding capacity to the Snail promoter region, ultimately blocking Snail transcription activity. Kinase cascade analysis revealed that phosphorylation of MEK3/6 and p38MAPK was inhibited by AA treatment. Moreover, knockdown of p38MAPK enhanced AA-suppressed protein levels of MZF-1, Elk-1, and Snail, suggesting that p38MAPK influences prostate cancer cell metastasis. These results provide promise for AA as a future candidate in the development of drug therapies to prevent or treat prostate cancer metastasis.

Timosaponin AIII Inhibits Migration and Invasion Abilities in Human Cervical Cancer Cells through Inactivation of p38 MAPK-Mediated uPA Expression In Vitro and In Vivo

Cervical cancer is one of the most common gynecologic cancers globally that require novel approaches. Timosaponin AIII (TSAIII) is a steroidal saponin that displays beneficial effects in antitumor activities. However, the effect of TSAIII on human cervical cancer remains unknown. In this study, we found that TSAIII showed no influence on cell viability, cytotoxicity, cell cycle distribution and apoptosis induction in human cervical cancer cells. TSAIII was revealed to have a significant inhibitory effect on cell migration and invasion through the downregulation of invasion-related uPA expression and p38 MAPK activation in both human cervical cancer cells and cervical cancer stem cells (CCSCs), indicating that the p38 MAPK-uPA axis mediated the TSAIII-inhibited capacity of cellular migration and invasion. In a synergistic inhibition assay, a TSAIII plus p38 siRNA cotreatment revealed a greater inhibition of uPA expression, migration and invasion in human cervical cancer cells. In an immunodeficient mouse model, TSAIII significantly inhibited lung metastases from human cervical cancer SiHa cells without TSAIII-induced toxicity. These findings first revealed the inhibitory effects of TSAIII on the progression of human cervical cancer through its downregulation of p38 MAPK-uPA axis activation. Therefore, TSAIII might provide a potential strategy for auxiliary therapy in human cervical cancer.

Asiatic acid from centella asiatica exert anti-invasive ability in human renal cancer cells by modulation of ERK/p38MAPK-mediated MMP15 expression

BACKGROUND

Asiatic acid (AA) is a naturally pentacyclic triterpenoids extracted from traditional medicine Centella asiatica l. that has demonstrated possesses potential health benefits and antitumor ability. However, the precise anticancer effects and mechanisms by which AA impact RCC cells remains unclear.

METHODS

Cell proliferation and cell cycle distribution were detected by MTT, colony formation assay and PI stain by flow cytometry, respectively. Cell mobility and invasiveness were determined by in vitro migration and invasion assay. The secretory MMP15 was detected by ELISA assay. Quantitative RT-PCR, siRNA, and immunoblot were used to determine gene expression/regulation and protein expression, respectively. Antimetastatic effect of AA were performed to lung nodule numbers in vivo metastasis mice model. MMP15, pERK1/2 and p-p38MAPK expressions were determined by immunohistochemistry.

RESULTS

Our findings indicated cell proliferation and cell cycle distribution of RCC cells were not significantly influenced by AA treatment. AA suppressed cell migration, invasion and significantly down-regulated mRNA and protein expression of MMP-15 (Matrix Metallopeptidase-15). Activation of ERK1/2 and p38MAPK were inhibited with AA, whereas combined AA with siRNA-ERK or siRNA-p38MAPK markedly reduced the metastatic effect and decreased MMP-15 expression in 786-O and A498 cells. Finally, AA significantly reduced the lung metastasis formation and metastasis-related proteins of human 786-O cells in vivo metastasis mice model.

CONCLUSION

AA inhibits the metastatic properties of RCC cells via inhibition of the p-ERK/p-p38MAPK axis and the subsequent down-regulation of MMP-15 in vitro and in vivo. Further study of AA as a potential anti-metastatic agent for RCC is warranted.

Epithelial–mesenchymal transition: The history, regulatory mechanism, and cancer therapeutic opportunities

Epithelial–mesenchymal transition (EMT) is a program wherein epithelial cells lose their junctions and polarity while acquiring mesenchymal properties and invasive ability. Originally defined as an embryogenesis event, EMT has been recognized as a crucial process in tumor progression. During EMT, cell–cell junctions and cell–matrix attachments are disrupted, and the cytoskeleton is remodeled to enhance mobility of cells. This transition of phenotype is largely driven by a group of key transcription factors, typically Snail, Twist, and ZEB, through epigenetic repression of epithelial markers, transcriptional activation of matrix metalloproteinases, and reorganization of cytoskeleton. Mechanistically, EMT is orchestrated by multiple pathways, especially those involved in embryogenesis such as TGFβ, Wnt, Hedgehog, and Hippo, suggesting EMT as an intrinsic link between embryonic development and cancer progression. In addition, redox signaling has also emerged as critical EMT modulator. EMT confers cancer cells with increased metastatic potential and drug resistant capacity, which accounts for tumor recurrence in most clinic cases. Thus, targeting EMT can be a therapeutic option providing a chance of cure for cancer patients. Here, we introduce a brief history of EMT and summarize recent advances in understanding EMT mechanisms, as well as highlighting the therapeutic opportunities by targeting EMT in cancer treatment.

Platelet-Tumor Cell Hybrid Membrane-Camouflaged Nanoparticles for Enhancing Therapy Efficacy in Glioma

Purpose

Cell membrane-camouflaged nanoparticles (NPs) are drawing increasing attention because their surfaces acquire some characteristics of the cell membranes, making them a unique class of biomimetic materials for diverse applications. Modification of cell membrane or combination of different types of membranes can enhance their functionality.

Methods

We prepared platelet and tumor cell membrane camouflaged β-mangostin-loaded NPs, which were synthesized with platelet–C6 hybrid biomimetic coating, poly(lactic-co-glycolic acid), and β-mangostin (β-PCNPs). Then, we evaluated their targeting ability and anticancer activity against glioma in vitro and in vivo.

Results

Biomimetic coating enhanced active drug targeting and immune escape properties of nanocarrier in C6 and THP-1 cells, respectively, which improved their cytotoxicity. β-PCNPs were characterized to study the inherent properties of both source cells. Compared with bare β-NPs, β-PCNPs exhibited high tumor-targeting capability and induced apoptosis of C6 cells in vitro. Similarly, intravenous administration of drug through β-PCNPs resulted in enhanced tumor-targeting and exhibited excellent rate of inhibition of glioma tumor growth in mice. Moreover, the blood circulation time of drug in mice in the β-PCNP group was markedly prolonged and these mice exhibited better outcome than those in the β-NP group.

Conclusion

These results provide a new strategy of utilizing PCNPs as carriers for drug delivery, which improves the targeting efficiency and therapeutic efficacy of chemotherapeutic agents for glioma therapy.

The purple mangosteen (Garcinia mangostana): Defining the anticancer potential of selected xanthones

The purple mangosteen (Garcinia mangostana) is a popular Southeast Asian fruit that has been used traditionally for its health promoting benefits for years. Unique to the mangosteen are a class of phytochemicals known as xanthones that have been reported to display significant anti-cancer and anti-tumor activities, specifically through the promotion of apoptosis, targeting of specific cancer-related proteins, or modulation of cell signaling pathways. α-Mangostin, the most abundant xanthone isolated from the mangosteen, has received substantial attention as it has proven to be a potent phytochemical, specifically as an anticancer agent, in numerous different cancer cell studies and cancer animal models. While the mechanisms for these anticancer effects have been reported in many studies, lesser xanthones, including gartanin, β-mangostin, γ-mangostin, garcinone C, and garcinone E, and mangosteen extracts from the pericarp, roots, rind, and stem show promise for their anticancer activity but their mechanisms of action are not as well developed and remain to be determined. Mangosteen products appear safe and have been well tolerated in human clinical trials where they show antioxidant activity, though their clinical anticancer activity has not yet been evaluated. This review summarizes the work that has been done to explore and explain the anticancer and antitumor activities of α-mangostin, lesser xanthones, and mangosteen extracts in vitro, in vivo, and in humans in various cancers.

Corosolic Acid Attenuates the Invasiveness of Glioblastoma Cells by Promoting CHIP-Mediated AXL Degradation and Inhibiting GAS6/AXL/JAK Axis

Corosolic acid (CA), a bioactive compound obtained from Actinidia chinensis, has potential anti-cancer activities. Glioblastoma (GBM) is a malignant brain tumor and whether CA exerts anti-cancer activity on GBM remains unclear. This study was aimed to explore the anticancer activity and its underlying mechanism of CA in GBM cells. Our findings showed that CA ≤ 20 μM did not affect cell viability and cell proliferative rate of normal astrocyte and four GBM cells. Notably, 10 or 20 μM CA significantly inhibited cell migration and invasion of three GBM cells, decreased the protein level of F-actin and disrupted F-actin polymerization in these GBM cells. Further investigation revealed that CA decreased AXL level by promoting ubiquitin-mediated proteasome degradation and upregulating the carboxyl terminus of Hsc70-interacting protein (CHIP), an inducer of AXL polyubiquitination. CHIP knock-down restored the CA-reduced AXL and invasiveness of GBM cells. Additionally, we observed that CA-reduced Growth arrest-specific protein 6 (GAS6) and inhibited JAK2/MEK/ERK activation, and GAS6 pre-treatment restored attenuated JAK2/MEK/ERK activation and invasiveness of GBM cells. Furthermore, molecular docking analysis revealed that CA might bind to GAS6 and AXL. These findings collectively indicate that CA attenuates the invasiveness of GBM cells, attributing to CHIP upregulation and binding to GAS6 and AXL and subsequently promoting AXL degradation and downregulating GAS6-mediated JAK2/MEK/ERK cascade. Conclusively, this suggests that CA has potential anti-metastatic activity on GBM cells by targeting the CHIP/GAS6/AXL axis.

Cytotoxic and Antiproliferative Effects of β-Mangostin on Rat C6 Glioma Cells Depend on Oxidative Stress Induction via PI3K/AKT/mTOR Pathway Inhibition

Background

Glioma is the most common malignant tumor of the nervous system, which accounts for more than 45% of central nervous system tumors and seriously threatens our health. Because of high mortality rate, limitations, and many complications of traditional treatment methods, new treatment methods are urgently needed. β-Mangostin is a natural compound derived from the fruit of Garcinia mangostana L. and it has anticancer activity in several types of cancer cells. However, the antitumor effect of β-mangostin in glioma has not been clarified. Hence, this study aimed to investigate its therapeutic effects on gliomas.

Materials and Methods

To study the effect of β-mangostin on glioma cells, cell viability assay, reactive oxygen species production, cell cycle, apoptosis, and mitochondrial membrane potential were evaluated in the C6 cell line in vitro. Immunofluorescence and Western blotting were used to analyze protein expression and phosphorylation to study its mechanism of action. A subcutaneous xenograft model was used to investigate the effect of β-mangostin on tumorigenesis in vivo.

Results

We found that β-mangostin can inhibit glioma cell growth and induce oxidative damage in vitro. In addition, it reduces the phosphorylated form levels of PI3K, AKT and mTOR. Furthermore, the phosphorylated form levels of PI3K, AKT and mTOR were increased after the PI3K inhibitor was added. In vivo experiments showed that β-mangostin can inhibit tumor growth as shown by its reduced size and weight.

Conclusion

This study suggests that β-mangostin can inhibit cell proliferation and induce oxidative damage in cells. It is the first study to demonstrate that β-mangostin induces oxidative damage in glioma cells by inhibiting the PI3K/AKT/mTOR signaling pathway.