Induction of autophagy by an oleanolic acid derivative, SZC017, promotes ROS-dependent apoptosis through Akt and JAK2/STAT3 signaling pathway in human lung cancer cells

A Preliminary Report Regarding the Morphological Changes of Nano-Enabled Pharmaceutical Formulation on Human Lung Carcinoma Monolayer and 3D Bronchial Microtissue

Background and Objectives: Nowadays, the development of enabled pharmaceutical nanoparticles of solid lipid type is continuously growing, because they have the potential to be used for targeted drug release leading to an increased effect of chemotherapy, being used in lung cancer nano-diagnosis and nano-therapy. The current study reports the preliminary results obtained regarding the biological effect of a new nano-enabled pharmaceutical formulation in terms of its cytotoxic and biosafety profile. Materials and Methods: The pharmaceutical formulations consist of solid lipid nanoparticles (SLN) obtained via the emulsification-diffusion method by loading green iron oxide nanoparticles (green-IONPs) with a pentacyclic triterpene (oleanolic acid-OA). Further, a complex biological assessment was performed, employing three-dimensional (3D) bronchial microtissues (EpiAirwayTM) to determine the biosafety profile of the SLN samples. The cytotoxic potential of the samples was evaluated on human lung carcinoma, using an in vitro model (A549 human lung carcinoma monolayer). Results: The data revealed that the A549 cell line was strongly affected after treatment with SLN samples, especially those that contained OA-loaded green-IONPs obtained with Ocimum basilicum extract (under 30% viability rates). The biosafety profile investigation of the 3D normal in vitro bronchial model showed that all the SLN samples negatively affected the viability of the bronchial microtissues (below 50%). As regards the morphological changes, all the samples induce major changes such as loss of the surface epithelium integrity, loss of epithelial junctions, loss of cilia, hyperkeratosis, and cell death caused by apoptosis. Conclusions: In summary, the culprit for the negative impact on viability and morphology of 3D normal bronchial microtissues could be the too-high dose (500 µg/mL) of the SLN sample used. Nevertheless, further adjustments in the SLN synthesis process and another complex in vitro evaluation will be considered for future research.

Mechanism study of oleanolic acid derivative, K73-03, inducing cell apoptosis in hepatocellular carcinoma

Oleanolic acid (3β-hydroxyolean-12-en-28-oic acid, OA) is a kind of pentacyclic triterpene, which widely distributes in nature. OA possesses a powerful anti-cancer effect; however, its low solubility limits its bioavailability and application. In this study, a new OA derivative, K73-03, was used to determine its effect on liver cancer cells and detailed molecular mechanisms. Here, we show that K73-03 may lead to the disorder of mitochondria in HepG2 cells, leading to excessive ROS production and apoptosis in cells. Meanwhile, K73-03 could induce cell apoptosis by inhibiting JAK2/STAT3 pathway and NF-κB/P65 pathway. Collectively, this study may provide a preliminary basis for further cancer treatment of hepatocellular carcinoma.

Natural Products as Anticancer Agents: Current Status and Future Perspectives

Natural products have been an invaluable and useful source of anticancer agents over the years. Several compounds have been synthesized from natural products by modifying their structures or by using naturally occurring compounds as building blocks in the synthesis of these compounds for various purposes in different fields, such as biology, medicine, and engineering. Multiple modern and costly treatments have been applied to combat cancer and limit its lethality, but the results are not significantly refreshing. Natural products, which are a significant source of new therapeutic drugs, are currently being investigated as potential cytotoxic agents and have shown a positive trend in preclinical research and have prompted numerous innovative strategies in order to combat cancer and expedite the clinical research. Natural products are becoming increasingly important for drug discovery due to their high molecular diversity and novel biofunctionality. Furthermore, natural products can provide superior efficacy and safety due to their unique molecular properties. The objective of the current review is to provide an overview of the emergence of natural products for the treatment and prevention of cancer, such as chemosensitizers, immunotherapeutics, combinatorial therapies with other anticancer drugs, novel formulations of natural products, and the molecular mechanisms underlying their anticancer properties.

An oleanolic acid derivative, K73-03, inhibits pancreatic cancer cells proliferation in vitro and in vivo via blocking EGFR/Akt pathway

Oleanolic acid (OA) and its derivatives show potent anticancer function. Pancreatic cancer (PC) is the fourth core motive of cancer-related deaths worldwide. Epidermal growth factor receptor (EGFR) has been implicated in PC and has been validated as a therapeutic target. Our study demonstrated that K73-03, an OA derivative, was identified as a potent inhibitor of EGFR by using reverse pharmacophore screening and molecular dynamics simulation assays. Moreover, Western blot analysis showed that K73-03 markedly suppressed the levels of phosphorylated-EGFR (p-EGFR) and phosphorylated-Akt (p-Akt). The inhibitory effect of K73-03 on PC cells was assessed in vitro and in vivo. Mechanistically, K73-03 effectively inhibited the cell proliferation of PC cells, and induced apoptosis and autophagy of ASPC-1 cells in a dose-dependent manner. Additionally, pretreatment with chloroquine, an autophagy inhibitor, significantly inhibited K73-03-induced autophagy and enhanced K73-03-induced apoptotic cell death. K73-03 also strongly repressed ASPC-1 cells xenograft growth in vivo. Thus, all these findings provided new clues about OA analog K73-03 as an effective anticancer agent targeted EGFR against ASPC-1 cells, it is worth further evaluation in the future.

Anticancer activity of Mannich bases: a review of recent literature

This report summarizes the latest published data on the antiproliferative action and cytotoxic activity of Mannich bases, a structurally heterogeneous category of chemical entities that includes compounds which are synthesized via the grafting of an aminomethyl function onto diverse substrates by means of the Mannich reaction. The present overview of the topic is an update to the information assembled in a previously published review that covered the literature up to 2014.

A Scientometric Visualization Analysis for Natural Products on Cancer Research from 2008 to 2020

Background: An increasing number of studies have shown that natural products have anti-tumor effects, and it has become a hotspot in cancer research. However, few bibliometric analyses have been examined in this field systematically. The current study aimed to explore the status and provide the developing trends in the natural products on cancer research.

Methods: Publications on natural products in cancer research were extracted from the Web of Science core collection database. CiteSpace (5.6.R3) software and GraphPad prism 6 were used to analyze and plot the references.

Results: On February 1, 2021, 34,611 records of natural products in cancer research published from 2008 to 2020 were collected. The United States was the driving force, with a strong academic reputation in this area. The top-contributing institution was the Chinese Academy of Sciences. Most publications were published in Molecules. Efferth Thomas was the most prolific author, while Newman DJ was the most cited and frequently co-cited author. Flavonoid, curcumin, and polyphenol were the most widely studied natural products. Oleanolic acid and rosmarinic acid have gradually become research hotspots recently. Breast cancer, prostate cancer, and colorectal cancer were the most common types of cancer in this field. “Natural killer cell” was the leading research hotspot. The keywords of “leaf extract,” “molecular docking” and “gold nanoparticle” appeared most recently as research frontiers.

Conclusion: Our results provided a general overview of the major research directions of natural products research in cancer. The mechanisms of natural products, especially those related to molecular docking, gold nanoparticle, gut microbiota, and immune checkpoints may soon become hotspots and should be closely monitored.

RANKL expression of primary osteoblasts is enhanced by an IL-17-mediated JAK2/STAT3 pathway through autophagy suppression

Objective: Interleukin-17 (IL-17), produced by T helper (Th)-17 cells, is a potent regulator of bone homeostasis. Osteoblasts are key cells that orchestrate inflammatory bone destruction and bone remodeling. This study examines the effect of different concentrations of IL-17 on osteogenesis and receptor activator of nuclear factor-kappa B ligand (RANKL) expression of primary osteoblasts.Methods: First, the growth of primary osteoblasts was evaluated. Second, we assessed the effects of IL-17 on the level of autophagy and the related Janus activated kinase 2 (JAK2) and downstream signal transducer and activator of transcription 3 (STAT3) signaling pathway. Next, osteogenic activity in different concentrations of IL-17 was tested. Finally, the specific JAK2/STAT3 signaling pathway inhibitor AG490 and autophagy inhibitor 3-MA were used to investigate the involvement of this pathway and autophagy in IL-17-induced regulation of RANKL expression.Results: Initially, we found that IL-17 treatment promoted growth of osteoblasts in a time- and dose-dependent manner. Next, we showed that low levels of IL-17 promoted autophagy activity, whereas the opposite was observed at high levels of IL-17. Moreover, high levels of IL-17 activated the JAK2/STAT3 signaling pathway, although this effect was reversed by upregulation of autophagy. Furthermore, our findings indicated that high concentrations of IL-17 promoted the differentiation, calcification, and RANKL expression of murine osteoblasts via activation of the JAK2/STAT3 pathway. Importantly, downregulation of autophagy at high IL-17 concentrations further enhanced RANKL expression via suppressing the JAK2/STAT3 cascade.Conclusion: Overall, our findings demonstrate, for the first time, that IL-17 modulates RANKL expression of osteoblasts through an autophagy-JAK2-STAT3 signaling pathway, thus affecting bone metabolism.

Identification of potential descriptors of water-soluble fullerene derivatives responsible for antitumor effects on lung cancer cells via QSAR analysis

Water-soluble fullerene derivatives are actively investigated as potential drugs for cancer treatment due to their favorable membranotropic properties. Herein, cytotoxic effects of twenty fullerene derivatives with different solubilizing addends were evaluated in three different types of non-small-cell lung carcinoma (NSCLC). The potential structural descriptors of the solubilizing addends related to the inhibitory activities on each type of lung cancer cell were investigated by the quantitative structure–activity relationship (QSAR) approach. The determination coefficient r² for the recommended QSAR model were 0.9325, 0.8404, and 0.9011 for A549, H460, and H1299 cell lines, respectively. The results revealed that the chemical features of the fullerene-based compounds including aromatic bonds, sulfur-containing aromatic rings, and oxygen atoms are favored properties and promote the inhibitory effects on H460 and H1299 cells. Particularly, thiophene moiety is the key functional group, which was positively correlated with strong inhibitory effects on the three types of lung cancer cells. The useful information obtained from our regression models may lead to the design of more efficient inhibitors of the three types of NSCLC.

Cytisine exerts anti-tumour effects on lung cancer cells by modulating reactive oxygen species-mediated signalling pathways

Cytisine is a natural product isolated from plants and is a member of the quinolizidine alkaloid family. This study aims to investigate the effect of cytisine in human lung cancer. Cell viability was determined using the CCK-8 assay, and the results showed that cytisine inhibited the growth of lung cancer cell lines. The apoptotic effects were evaluated using flow cytometry, and the results showed that cytisine induced mitochondrial-dependent apoptosis through loss of the mitochondrial membrane potential; increased expression of BAD, cleaved caspase-3, and cleaved-PARP; and decreased expression levels of Bcl-2, pro-caspase-3, and pro-PARP. In addition, cytisine caused G2/M phase cell cycle arrest that was associated with inhibiting the AKT signalling pathway. During apoptosis, cytisine increased the phosphorylation levels of JNK, p38, and I-κB, and decreased the phosphorylation levels of ERK, STAT3, and NF-κB. Furthermore, cytisine treatment led to the generation of ROS, and the NAC attenuated cytisine-induced apoptosis. In vivo, cytisine administration significantly inhibited the lung cancer cell xenograft tumorigenesis. In conclusion, cytisine plays a critical role in suppressing the carcinogenesis of lung cancer cells through cell cycle arrest and induction of mitochondria-mediated apoptosis, suggesting that it may be a promising candidate for the treatment of human lung cancer.

Methyloleanolate Induces Apoptotic And Autophagic Cell Death Via Reactive Oxygen Species Generation And c-Jun N-terminal Kinase Phosphorylation

Background

To develop a potent anticancer agent similar to oleanolate, the underlying mechanisms of its derivative, methyloleanolate, in the apoptosis and autophagy of A549 and H1299 cells were elucidated.

Purpose

The aim of the present study was to investigate the effect of methyloleanolate in inducing apoptotic and autophagic cell death in cancer cells.

Materials and methods

Flow cytometric analysis with Annexin V/PI staining, Western blot analysis, and immunofluorescence analysis were conducted in A549 and H1299 cells.

Results

Methyloleanolate increased the fraction of Annexin V/PI apoptotic cells and activated caspase-8, caspase-3, and death receptor 5 (DR5) more than oleanolate in A549 and H1299 cells pretreated with pancaspase inhibitor z-VAD-fmk and DR5 depletion. Also, methyloleanolate induced autophagic features of microtubule-associated protein light chain 3 3BII (LC3BII) conversion and puncta in A549 and H1299 cells, along with autophagosomes and vacuoles. Methyloleanolate blocked autophagy flux for impaired autophagy and chloroquine (CQ)-enhanced microtubule-associated protein LC3BII accumulation and cytotoxicity in A549 and H1299 cells, although 3-methyladenine (3-MA) did not. Interestingly, LC3BII accumulation was detected only in methyloleanolate-treated autophagy-related gene 5 (ATG5)^+/+ mouse embryonic fibroblast (MEF) cells but not in ATG5 ^-/- MEF cells. Methyloleanolate reduced p-mTOR but activated p-c-Jun N-terminal kinases and reactive oxygen species production in A549 and H1299 cells. Conversely, n-acetyl-l-cysteine and SP600125 blocked apoptotic and autophagic cascades caused by methyloleanolate in A549 and H1299 cells.

Conclusion

Overall, the findings suggest that methyloleanolate induces apoptotic and autophagic cell death in non-small cell lung cancers via reactive oxygen species generation and c-Jun N-terminal kinase phosphorylation.

TGF-β1 reduces the oxidative stress-induced autophagy and apoptosis in rat annulus fibrosus cells through the ERK signaling pathway

Background

The aim of this study is to explore the effects of TGF-β1 on autophagy and apoptosis induced by exogenous hydrogen peroxide (H₂O₂) in annulus fibrosus (AF) cells and possible signal pathways involved in this process.

Methods

AF cells were isolated from rat lumbar discs and subjected to different concentrations of exogenous H₂O₂ (50, 100, 200 μmol/L) for different time periods (0.5, 1, 2, and 4 h). Cell viability was determined by CCK-8 assay, and the levels of autophagy and apoptosis were evaluated by Western blotting and caspase 3, 8, 9 activity assay. By administration with different concentrations of TGF-β1 (5, 10, 20 ng/mL), the effects of TGF-β1 on autophagy and apoptosis induced by H₂O₂ were observed, and the possible signaling pathways were also investigated by using various apoptosis inhibitors or an autophagy inhibitor Bafilomycin A (Baf A) in AF cells.

Results

H₂O₂ significantly impaired cell viability in a dose- and time-dependent manner. H₂O₂ also induced a sudden and the highest level of autophagy at 1 h, and gradually increased apoptosis through ERK pathway. The mitochondrial pathway was involved in H₂O₂-induced apoptosis in AF cells. TGF-β1 reduced the expression of p-ERK and downregulated the expressions of Beclin-1, LC3 II/I, and mitochondrial-related apoptotic proteins (Bax/Bcl-2, caspase-9). Meanwhile, TGF-β1 downregulated the level of intracellular H₂O₂ through upregulating the expression level of glutathione peroxidase-1 (GPx-1).

Conclusions

TGF-β1 reduced autophagy and apoptosis induced by exogenous H₂O₂ through downregulating the expression of ERK in AF cells. TGF-β1 could downregulate the level of ERK and intracellular H₂O₂ by upregulating GPx-1.

EZH2 inhibition suppresses bladder cancer cell growth and metastasis via the JAK2/STAT3 signaling pathway

The aim of the current study was to investigate the role of enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) in the progression of bladder cancer. Human bladder cancer tissue samples were analyzed by immunohistochemistry, and the association between the clinicopathological parameters and EZH2 expression was analyzed. The proliferation, apoptosis and migration ability of the human bladder cancer cell lines E-J and 5637 with or without the EZH2 inhibitor UNC1999 was investigated. The effect of UNC1999 was further explored in a xenograft model of nude mice. The in vivo and in vitro expression levels of EZH2, janus kinase 2, signal transducer and activator of transcription 3 and their phosphorylated forms were examined by western blotting. The expression levels of EZH2, JAK2 and STAT3 were increased in bladder cancer tissue compared with normal adjacent tissue. Furthermore, the expression of EZH2 was increased in tumors with a higher TNM Classification of Malignant Tumors stage and histological grade compared with tumors with a lower stage and grade. The human bladder cancer cell lines E-J and 5637 treated with UNC1999 demonstrated reduced cell proliferation, apoptosis and migration compared with cells treated without UNC1999. Additionally, EZH2 may promote the proliferation and migration of bladder cancer via the JAK2/STAT3 pathway. EZH2 may serve an important role in the proliferation and migration of human bladder cancer cells, and may aid in the development of novel treatment strategies for bladder cancer.

Chrysophanol attenuated isoproterenol-induced cardiac hypertrophy by inhibiting Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway

Cardiac hypertrophy is a common pathological change found in various cardiovascular diseases. Although it has long been recognized as an important risk factor responsible for heart failure, there is still a lack of effective treatments in clinic. Chrysophanol is a natural compound with multiple biological activities and protective roles in the cardiovascular system. However, its potential effect on cardiac hypertrophy remains unclear. In the current study, we found that chrysophanol could protect against isoproterenol (ISO)-induced cardiac hypertrophy both in vitro and in vivo. Increase of cell surface and hypertrophic marker expression induced by ISO in neonatal rat cardiomyocytes was downregulated by chrysophanol. Moreover, chrysophanol ameliorated the abnormal changes of cardiac structure and function in rats subjected to ISO injection, as shown by echocardiography and morphometry measurements. Further mechanistical investigation demonstrated that chrysophanol inhibited phosphorylation of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) induced by ISO. Nuclear translocation of STAT3 and transcription of downstream genes promoted by ISO treatment were also remarkably suppressed by chrysophanol. Taken together, our findings revealed that chrysophanol attenuated ISO-induced cardiac hypertrophy by inhibiting JAK2/STAT3 signaling pathway. Chrysophanol may be a potential candidate compound for the prevention and treatment of hypertrophy-related cardiomyopathy.

Antrodin C, an NADPH Dependent Metabolism, Encourages Crosstalk between Autophagy and Apoptosis in Lung Carcinoma Cells by Use of an AMPK Inhibition-Independent Blockade of the Akt/mTOR Pathway

The current study aims to explore the possible anti-lung carcinoma activity of ADC as well as the underlying mechanisms by which ADC exerts its actions in NSCLC. Findings showed that ADC potently inhibited the viability of SPCA-1, induced apoptosis triggered by ROS, and arrested the cell cycle at the G2/M phase via a P53 signaling pathway. Interestingly, phenomena such as autophagosomes accumulation, conversion of the LC3-I to LC3-II, etc., indicated that autophagy could be activated by ADC. The blockage of autophagy-augmented ADC induced inhibition of cell proliferation, while autophagy activation restored cell death, indicating that autophagy had a protective effect against cell death which was induced by ADC treatment. Meanwhile, ADC treatment suppressed both the Akt/mTOR and AMPK signaling pathways. The joint action of both ADC and the autophagy inhibitor significantly increased the death of SPCA-1. An in vitro phase I metabolic stability assay showed that ADC was highly metabolized in SD rat liver microsomes and moderately metabolized in human liver microsomes, which will assist in predicting the outcomes of clinical pharmacokinetics and toxicity studies. These findings imply that blocking the Akt/mTOR signaling pathway, which was independent of AMPK inhibition, could activate ADC-induced protective autophagy in non-small-cell lung cancer cells.

Sanshool improves UVB-induced skin photodamage by targeting JAK2/STAT3-dependent autophagy

Ultraviolet radiation is markedly increased because of pollution and the depletion of the stratospheric ozone layer. Excessive exposure to sunlight can negatively affect the skin, resulting in sunburn, photo-aging, or skin cancer. In this study, we first determined the photoprotective effect of sanshool, a major component in Zanthoxylum bungeanum, on UVB-irradiated responses in human dermal fibroblasts (HDFs) and nude mouse. We found that sanshool treatment can protect cells against the effects of UVB irradiation by (i) increasing cell viability, (ii) inhibiting MMP expression, and (iii) inducing autophagy. We also used the recombinant CSF2 or anti-CSF2 antibody co-cultured with human dermal fibroblasts (HDFs) and found that CSF2 contributes to sanshool-induced autophagy. Sanshool hindered the UVB-induced activation of JAK2-STAT3 signaling in HDFs, thereby inhibiting the expression of MMPs and activation of autophagic flux. Exposure of the dorsal skin of hairless mice to UVB radiation and subsequent topical application of sanshool delayed the progression of skin inflammation, leading to autophagy and inhibiting the activation of JAK2-STAT3 signaling. These results provide a basis for the study of the photoprotective effect of sanshool and suggest that it can be potentially used as an agent against UVB-induced skin damage in humans.