Hyperforin induces apoptosis through extrinsic/intrinsic pathways and inhibits EGFR/ERK/NF-κB-mediated anti-apoptotic potential in glioblastoma

Xerophenone H, a naturally-derived proteasome inhibitor, triggers apoptosis and paraptosis in lung cancer

BACKGROUND

Polycyclic polyprenylated acylphloroglucinols (PPAPs) characterized by unique chemical architectures, exhibit diverse pharmacological activities. Xerophenone H (XeH) is a PPAP extracted from the plant Garcinia multiflora Champ. ex Benth. (Clusiaceae) with a novel and unique chemical structure. Although in vitro screening has revealed the anti-cancer activity of XeH, whose in vivo effectiveness and mechanistic basis required systematic investigation.

METHODS

Cytotoxic effects were evaluated through MTT and colony formation assays. A subcutaneous xenograft model was established to assess in vivo anti-cancer efficacy. To elucidate the underlying mechanism of the anti-cancer effect of XeH, RNA-sequencing and western blotting were performed. A proteasome activity assay was conducted to quantify the effect of XeH. Molecular docking and cellular thermal shift assays were conducted to identify the potential molecular target for XeH.

RESULTS

XeH demonstrated concentration-dependent cytotoxicity in A549 cells (IC₅₀ = 12.16 μM at 48 h). Intratumoral administration (10 mg/kg triweekly) achieved 38.6 % tumor growth inhibition. XeH simultaneously triggered apoptosis and paraptosis in A549 and H460 cells. Mechanistically, XeH promoted the formation of protein aggregates and induced significant endoplasmic reticulum stress in lung cancer cells by directly interacting with PSMB5 and inhibiting proteasome activity.

CONCLUSIONS

XeH, a novel PPAP, was identified as a novel proteasome inhibitor. It effectively downregulated proteasome activity, and induced both apoptosis and paraptosis in lung cancer cells.

Discovery of flavonoid-containing compound Lupalbigenin as anti-NSCLC cancer agents via suppression of EGFR and ERK1/2 pathway

Epidermal growth factor receptor exon 20 insertions (EGFR Ex20ins) driver mutations in non-small cell lung cancer (NSCLC) is insensitive to EGFR tyrosine kinase inhibitors (TKIs). Therefore, it is necessary to develop more novel strategy to address the limitations of existing therapies targeting EGFR-mutated NSCLC. Lupalbigenin (LB), a flavonoid compound extracted from Derris scandens, has shown preclinical activity in lung cancer. However, the activity of LB in Ex20ins-driven tumors has not yet been elucidated. In this study, a series of stable BaF/3 cell-line that contains a high proportion (>90 %) of EGFR-eGFP Ex20ins were generated using an IL3-deprivation method. Ba/F3 cell models harboring dissimilar Ex20ins were used to characterize the antineoplastic mechanism of LB. Molecular docking confirmed that the LB could effectively bind to key target EGFR. The in vitro anticancer activity of LB was investigated in engineered Ba/F3 cells bearing diverse uncommon EGFR mutations. LB was shown to be more potent in inhibiting the viability of various uncommon EGFR-mutated cell lines. Mechanistic studies disclosed that LB repressed EGFR phosphorylation and downstream survival pathways in Ba/F3 cells expressing EGFR Ex20ins, resulting in caspase activation by activating the intrinsic apoptotic pathway. Further analyses showed that LB significantly induced G0/G1 cell cycle arrest and apoptosis in cells. LB also reduced the protein expression levels of CDK4, CDK6, CDK8, cyclin D1, cyclin A2, and Bcl2 and promoted the expression of cytochrome C, p27, and p53. In summary, we explored the possible potential targets of LB through network pharmacology and verified the target using in vitro experiments. Furthermore, our results demonstrated that LB showed potential anti-Ex20ins cancer activity through suppression of the EGFR and ERK1/2 signaling pathway in Ba/F3 cells bearing two to three amino acid insertion mutations. These findings suggested that LB might be valuable for further investigation as a potential candidate in the treatment of associated diseases.

A comprehensive apoptotic assessment of niloticin in cervical cancer cells: a tirucallane-type triterpenoid from Aphanamixis polystachya (Wall.) Parker

Pharmacologically active small organic molecules derived from natural resources are prominent drug candidates due to their inherent structural diversity. Herein, we explored one such bioactive molecule, niloticin, which is a tirucallane-type triterpenoid isolated from the stem barks of Aphanamixis polystachya (Wall.) Parker. After initial screening with other isolated compounds from the same plant, niloticin demonstrated selective cytotoxicity against cervical cancer cells (HeLa) with an IC50 value of 11.64 μM. Whereas the compound exhibited minimal cytotoxicity in normal epithelial cell line MCF-10A, with an IC50 value of 83.31 μM. Subsequently, in silico molecular docking studies of niloticin based on key apoptotic proteins such as p53, Fas, FasL, and TNF β revealed striking binding affinity, reflecting docking scores of -7.2, -7.1, -6.8, and -7.2. Thus, the binding stability was evaluated through molecular dynamic simulation. In a downstream process, the apoptotic capability of niloticin was effectively validated through in vitro fluorimetric assays, encompassing nuclear fragmentation. Additionally, an insightful approach involving surface-enhanced Raman spectroscopy (SERS) re-establishes the occurrence of DNA cleavage during cellular apoptosis. Furthermore, niloticin was observed to induce apoptosis through both intrinsic and extrinsic pathways. This was evidenced by the upregulation of upstream regulatory molecules such as CD40 and TNF, which facilitate the activation of caspase 8. Concurrently, niloticin-induced p53 activation augmented the expression of proapoptotic proteins Bax and Bcl-2 and downregulation of IAPs, leading to the release of cytochrome C and subsequent activation of caspase 9. Therefore, the reflection of mitochondrial-mediated apoptosis is in good agreement with molecular docking studies. Furthermore, the anti-metastatic potential was evidenced by wound area closure and Ki67 expression patterns. This pivotal in vitro assessment confirms the possibility of niloticin being a potent anti-cancer drug candidate, and to the best of our knowledge, this is the first comprehensive anticancer assessment of niloticin in HeLa cells.

Targeting epidermal growth factor receptor and its downstream signaling pathways by natural products: A mechanistic insight

The epidermal growth factor receptor (EGFR) is a transmembrane receptor tyrosine kinase (RTK) that maintains normal tissues and cell signaling pathways. EGFR is overactivated and overexpressed in many malignancies, including breast, lung, pancreatic, and kidney. Further, the EGFR gene mutations and protein overexpression activate downstream signaling pathways in cancerous cells, stimulating the growth, survival, resistance to apoptosis, and progression of tumors. Anti-EGFR therapy is the potential approach for treating malignancies and has demonstrated clinical success in treating specific cancers. The recent report suggests most of the clinically used EGFR tyrosine kinase inhibitors developed resistance to the cancer cells. This perspective provides a brief overview of EGFR and its implications in cancer. We have summarized natural products-derived anticancer compounds with the mechanistic basis of tumor inhibition via the EGFR pathway. We propose that developing natural lead molecules into new anticancer agents has a bright future after clinical investigation.

Cellular neurobiology of hyperforin

Hyperforin is a phloroglucinol derivative isolated from the medicinal plant Hypericum perforatum (St John's wort, SJW). This lipophilic biomolecule displays antibacterial, pro-apoptotic, antiproliferative, and anti-inflammatory activities. In addition, in vitro and in vivo data showed that hyperforin is a promising molecule with potential applications in neurology and psychiatry. For instance, hyperforin possesses antidepressant properties, impairs the uptake of neurotransmitters, and stimulates the brain derived neurotrophic factor (BDNF)/TrkB neurotrophic signaling pathway, the adult hippocampal neurogenesis, and the brain homeostasis of zinc. In fact, hyperforin is a multi-target biomolecule with a complex neuropharmacological profile. However, one prominent pharmacological feature of hyperforin is its ability to influence the homeostasis of cations such as Ca2+ , Na+ , Zn2+ , and H+ . So far, the pathophysiological relevance of these actions is currently unknown. The main objective of the present work is to provide an overview of the cellular neurobiology of hyperforin, with a special focus on its effects on neuronal membranes and the movement of cations.

Phlorotannins: Novel Orally Administrated Bioactive Compounds That Induce Mitochondrial Dysfunction and Oxidative Stress in Cancer

Mitochondrial dysfunction is an interesting therapeutic target to help reduce cancer deaths, and the use of bioactive compounds has emerged as a novel and safe approach to solve this problem. Here, we discuss the information available related to phlorotannins, a type of polyphenol present in brown seaweeds that reportedly functions as antioxidants/pro-oxidants and anti-inflammatory and anti-tumorigenic agents. Specifically, available evidence indicates that dieckol and phloroglucinol promote mitochondrial membrane depolarization and mitochondria-dependent apoptosis. Phlorotannins also reduce pro-tumorigenic, -inflammatory, and -angiogenic signaling mechanisms involving RAS/MAPK/ERK, PI3K/Akt/mTOR, NF-κB, and VEGF. In doing so, they inhibit pathways that favor cancer development and progression. Unfortunately, these compounds are rather labile and, therefore, this review also summarizes approaches permitting the encapsulation of bioactive compounds, like phlorotannins, and their subsequent oral administration as novel and non-invasive therapeutic alternatives for cancer treatment.

Borax regulates iron chaperone- and autophagy-mediated ferroptosis pathway in glioblastoma cells

Glioblastoma (GBM) is classified as a stage-IV glioma. Unfortunately, there are currently no curative treatments for GBM. Poly(rC)-binding protein 1 (PCBP1) is a cytosolic iron chaperone with diverse functions. PCBP1 is also known to regulate autophagy, but the role of PCBP1 in ferroptosis, iron-dependent cell death pathway, remains unrevealed in GBM cells. Here, we investigated the effects of borax, a boron compound, on the ferroptosis signaling pathway mediated by PCBP1 and autophagy. The study analyzed cell viability, proliferation, and cell cycle on U87-MG and HMC3 cells to investigate the effects of borax. After determining the cytotoxic concentrations of borax, morphological analyzes and measurement of PCBP1, Beclin1, malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase 4 (GPx4) and acyl-CoA synthetase long chain family member 4 (ACSL4) levels were performed. Finally, expression levels of PCBP1, Beclin1, GPx4 and ACSL4, and caspase-3/7 activity were determined. We found that borax reduced U87-MG cell viability in a concentration- and time-dependent manner. Additionally, borax altered cell proliferation and remarkably reduced S phase in the U87-MG cells and exhibited selectivity by having an opposite effect on normal cells (HMC3). According to DAPI staining, borax caused nuclear deficits in U87-MG cells. The result showed that borax in U87-MG cells induced reduction of the PCBP1, GSH, and GPx4 and enhancement of Beclin1, MDA, and ACSL4. Furthermore, borax triggered apoptosis by activating caspase 3/7 in U87-MG cells. Our study indicated that the borax has potential as an anticancer treatment for GBM via regulating PCBP1/Beclin1/GPx4/ACSL4 signaling pathways.

Antrodia camphorata and coenzyme Q0 , a novel quinone derivative of Antrodia camphorata, impede HIF-1α and epithelial-mesenchymal transition/metastasis in human glioblastoma cells

Antrodia camphorata (AC) and Coenzyme Q₀ (CoQ₀ ), a novel quinone derivative of AC, exhibits antitumor activities. The present study evaluated EMT/metastasis inhibition and autophagy induction aspects of AC and CoQ₀ in human glioblastoma (GBM8401) cells. Our findings revealed that AC treatment (0-150 μg/mL) hindered tumor cell proliferation and migration/invasion in GBM8401 cells. Notably, AC treatment inhibited HIF-1α and EMT by upregulating epithelial marker protein E-cadherin while downregulating mesenchymal proteins Twist, Slug, Snail, and β-catenin. There was an appearance of the autophagy markers LC3-II and p62/SQSTM1, while ATG4B was downregulated by AC treatment. We also found that CoQ₀ (0-10 μM) could inhibit migration and invasion in GBM8401 cells. In particular, E-cadherin was elevated and N-cadherin, Vimentin, Twist, Slug, and Snail, were reduced upon CoQ₀ treatment. In addition, MMP-2/-9 expression and Wnt/β-catenin pathways were downregulated. Furthermore, autophagy inhibitors 3-MA or CQ reversed the CoQ₀ -elicited suppression of migration/invasion and metastasis-related proteins (Vimentin, Snail, and β-catenin). Results suggested autophagy-mediated antiEMT and antimetastasis upon CoQ₀ treatment. CoQ₀ inhibited HIF-1α and metastasis in GBM8401 cells under normoxia and hypoxia. HIF-1α knockdown using siRNA accelerated CoQ₀ -inhibited migration. Finally, CoQ₀ exhibited a prolonged survival rate in GBM8401-xenografted mice. Treatment with Antrodia camphorata/CoQ₀ inhibited HIF-1α and EMT/metastasis in glioblastoma.

Hyperforin Elicits Cytostatic/Cytotoxic Activity in Human Melanoma Cell Lines, Inhibiting Pro-Survival NF-κB, STAT3, AP1 Transcription Factors and the Expression of Functional Proteins Involved in Mitochondrial and Cytosolic Metabolism

Hyperforin (HPF), the main component responsible for the antidepressant action of Hypericum perforatum, displays additional beneficial properties including anti-inflammatory, antimicrobic, and antitumor activities. Among its antitumor effects, HPF activity on melanoma is poorly documented. Melanoma, especially BRAF-mutated melanoma, is still a high-mortality tumor type and the currently available therapies do not provide solutions. We investigated HPF's antimelanoma effectiveness in A375, FO1 and SK-Mel-28 human BRAF-mutated cell lines. Cell viability assays documented that all melanoma cells were affected by low HPF concentrations (EC50% 2-4 µM) in a time-dependent manner. A Br-deoxy-uridine incorporation assay attested a significant reduction of cell proliferation accompanied by decreased expression of cyclin D1 and A2, CDK4 and of the Rb protein phosphorylation, as assessed by immunoblots. In addition, the expression of P21/waf1 and the activated form of P53 were increased in A375 and SK-Mel-28 cells. Furthermore, HPF exerts cytotoxic effects. Apoptosis is induced 24 h after HPF administration, documented by an increase of cleaved-PARP1 and a decrease of both Bcl2 and Bcl-xL expression levels. Autophagy is induced, attested by an augmented LC3B expression and augmentation of the activated form of AMPK. Moreover, HPF lowers GPX4 enzyme expression, suggesting ferroptosis induction. HPF has been reported to activate the TRPC6 Ca⁺⁺ channel and/or Ca⁺⁺ and Zn⁺⁺ release from mitochondria stores, increasing cytosolic Ca⁺⁺ and Zn⁺⁺ concentrations. Our data highlighted that HPF affects many cell-signaling pathways, including signaling induced by Ca⁺⁺, such as FRA1, pcJun and pCREB, the expression or activity of which are increased shortly after treatment. However, the blockage of the TRPC6 Ca⁺⁺ channel or the use of Ca⁺⁺ and Zn⁺⁺ chelators do not hinder HPF cytostatic/cytotoxic activity, suggesting that damages induced in melanoma cells may pass through other pathways. Remarkably, 24 h after HPF treatment, the expression of activated forms of the transcription factors NF-κB P65 subunit and STAT3 are significantly lowered. Several cytosolic (PGM2, LDHA and pPKM2) and mitochondrial (UQCRC1, COX4 and ATP5B) enzymes are downregulated by HPF treatment, suggesting a generalized reduction of vital functions in melanoma cells. In line with these results is the recognized ability of HPF to affect mitochondrial membrane potential by acting as a protonophore. Finally, HPF can hinder both melanoma cell migration and colony formation in soft agar. In conclusion, we provide evidence of the pleiotropic antitumor effects induced by HPF in melanoma cells.

How Should the Worldwide Knowledge of Traditional Cancer Healing Be Integrated with Herbs and Mushrooms into Modern Molecular Pharmacology?

Traditional herbal medicine (THM) is a "core" from which modern medicine has evolved over time. Besides this, one third of people worldwide have no access to modern medicine and rely only on traditional medicine. To date, drugs of plant origin, or their derivates (paclitaxel, vinblastine, vincristine, vinorelbine, etoposide, camptothecin, topotecan, irinotecan, and omacetaxine), are very important in the therapy of malignancies and they are included in most chemotherapeutic regimes. To date, 391,000 plant and 14,000 mushroom species exist. Their medical and biochemical capabilities have not been studied in detail. In this review, we systematized the information about plants and mushrooms, as well as their active compounds with antitumor properties. Plants and mushrooms are divided based on the regions where they are used in ethnomedicine to treat malignancies. The majority of their active compounds with antineoplastic properties and mechanisms of action are described. Furthermore, on the basis of the available information, we divided them into two priority groups for research and for their potential of use in antitumor therapy. As there are many prerequisites and some examples how THM helps and strengthens modern medicine, finally, we discuss the positive points of THM and the management required to transform and integrate THM into the modern medicine practice.

Extracellular vesicles derived from glioblastoma promote proliferation and migration of neural progenitor cells via PI3K-Akt pathway

BACKGROUND

Glioblastomas are lethal brain tumors under the current combinatorial therapeutic strategy that includes surgery, chemo- and radio-therapies. Extensive changes in the tumor microenvironment is a key reason for resistance to chemo- or radio-therapy and frequent tumor recurrences. Understanding the tumor-nontumor cell interaction in TME is critical for developing new therapy. Glioblastomas are known to recruit normal cells in their environs to sustain growth and encroachment into other regions. Neural progenitor cells (NPCs) have been noted to migrate towards the site of glioblastomas, however, the detailed mechanisms underlying glioblastoma-mediated NPCs' alteration remain unkown.

METHODS

We collected EVs in the culture medium of three classic glioblastoma cell lines, U87 and A172 (male cell lines), and LN229 (female cell line). U87, A172, and LN229 were co-cultured with their corresponding EVs, respectively. Mouse NPCs (mNPCs) were co-cultured with glioblastoma-derived EVs. The proliferation and migration of tumor cells and mNPCs after EVs treatment were examined. Proteomic analysis and western blotting were utilized to identify the underlying mechanisms of glioblastoma-derived EVs-induced alterations in mNPCs.

RESULTS

We first show that glioblastoma cell lines U87-, A172-, and LN229-derived EVs were essential for glioblastoma cell prolifeartion and migration. We then demonstrated that glioblastoma-derived EVs dramatically promoted NPC proliferation and migration. Mechanistic studies identify that glioblastoma-derived EVs achieve their functions via activating PI3K-Akt-mTOR pathway in mNPCs. Inhibiting PI3K-Akt pathway reversed the elevated prolfieration and migration of glioblastoma-derived EVs-treated mNPCs.

CONCLUSION

Our findings demonstrate that EVs play a key role in intercellular communication in tumor microenvironment. Inhibition of the tumorgenic EVs-mediated PI3K-Akt-mTOR pathway activation might be a novel strategy to shed light on glioblastoma therapy. Video Abstract.

Revealing the suppressive role of protein kinase C delta and p38 mitogen-activated protein kinase (MAPK)/NF-κB axis associates with lenvatinib-inhibited progression in hepatocellular carcinoma in vitro and in vivo

Nuclear factor-kappa B (NF-κB), an oncogenic transcription factor, modulates tumor formation and progression by inducing the expression of oncogenes involved in proliferation, survival, angiogenesis, and metastasis. Oral multikinase inhibitors, such as sorafenib, regorafenib, and lenvatinib have been used for the treatment of hepatocellular carcinoma (HCC). Both sorafenib and regorafenib were shown to abolish the NF-κB-mediated progression of HCC. However, the effect of lenvatinib on NF-κB-mediated progression of HCC is ambiguous. Therefore, the primary purpose of the present study was to evaluate the inhibitory effect of lenvatinib and its inhibitory mechanism on the NF-κB-mediated progression of HCC in vitro and in vivo. Here, we used two HCC cell lines to identify the cytotoxicity, apoptosis and metastasis effect of lenvatinib. We also applied a Hep3B-bearing animal model to investigate the therapeutic efficacy of lenvatinib on in vivo model. An NF-κB translocation assay, NF-κB reporter gene assay, a Western blotting assay and immunohistochemistry staining were used to investigate the underlying mechanism by which lenvatinib acts on HCC. In this study, we demonstrated that lenvatinib induced extrinsic/intrinsic apoptosis and suppressed the metastasis of HCC both in vitro and in vivo. Lenvatinib may also suppress NF-κB translocation and activation. We also found both protein kinase C delta (PKC-δ) and p38 mitogen-activated protein kinase (MAPK) inactivation participated in lenvatinib-reduced NF-κB signaling. In conclusion, this study reveals that the suppression of PKC-δ, and the p38 MAPK/NF-κB axis is associated with the lenvatinib-inhibited progression of HCC in vitro and in vivo.

Canonical transient receptor potential channels and their modulators: biology, pharmacology and therapeutic potentials

Canonical transient receptor potential channels (TRPCs) are nonselective, high calcium permeability cationic channels. The TRPCs family includes TRPC1, TRPC2, TRPC3, TRPC4, TRPC5, TRPC6, and TRPC7. These channels are widely expressed in the cardiovascular and nervous systems and exist in many other human tissues and cell types, playing several crucial roles in the human physiological and pathological processes. Hence, the emergence of TRPCs modulators can help investigate these channels’ applications in health and disease. It is worth noting that the TRPCs subfamilies have structural and functional similarities, which presents a significant difficulty in screening and discovering of TRPCs modulators. In the past few years, only a limited number of selective modulators of TRPCs were detected; thus, additional research on more potent and more selective TRPCs modulators is needed. The present review focuses on the striking desired therapeutic effects of TRPCs modulators, which provides intel on the structural modification of TRPCs modulators and further pharmacological research. Importantly, TRPCs modulators can significantly facilitate future studies of TRPCs and TRPCs related diseases.

Anti-Tumor Activity of Hypericum perforatum L. and Hyperforin through Modulation of Inflammatory Signaling, ROS Generation and Proton Dynamics

In this paper we review the mechanisms of the antitumor effects of Hypericum perforatum L. (St. John's wort, SJW) and its main active component hyperforin (HPF). SJW extract is commonly employed as antidepressant due to its ability to inhibit monoamine neurotransmitters re-uptake. Moreover, further biological properties make this vegetal extract very suitable for both prevention and treatment of several diseases, including cancer. Regular use of SJW reduces colorectal cancer risk in humans and prevents genotoxic effects of carcinogens in animal models. In established cancer, SJW and HPF can still exert therapeutic effects by their ability to downregulate inflammatory mediators and inhibit pro-survival kinases, angiogenic factors and extracellular matrix proteases, thereby counteracting tumor growth and spread. Remarkably, the mechanisms of action of SJW and HPF include their ability to decrease ROS production and restore pH imbalance in tumor cells. The SJW component HPF, due to its high lipophilicity and mild acidity, accumulates in membranes and acts as a protonophore that hinders inner mitochondrial membrane hyperpolarization, inhibiting mitochondrial ROS generation and consequently tumor cell proliferation. At the plasma membrane level, HPF prevents cytosol alkalization and extracellular acidification by allowing protons to re-enter the cells. These effects can revert or at least attenuate cancer cell phenotype, contributing to hamper proliferation, neo-angiogenesis and metastatic dissemination. Furthermore, several studies report that in tumor cells SJW and HPF, mainly at high concentrations, induce the mitochondrial apoptosis pathway, likely by collapsing the mitochondrial membrane potential. Based on these mechanisms, we highlight the SJW/HPF remarkable potentiality in cancer prevention and treatment.