• Environmental Mutagens and Carcinogens
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• v.23 no.2
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• pp.56-62
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• 2003

The liver progenitor cells could form a potential target cell population fore both tumor-initiating and -promoting chemicals. Induction of drug-metabolizing and antioxidant enzymes, including AhR-dependent CYP1A1, NQO-1 and AKR1C9, was detected in the rat liver epithelial WB-F344 "stem-like" cells. Additionally, WB-F344 cells express a functional, wild-type form of p53 protein, a biomarker of genotoxic events, and connexin 43, a basic structural unit of gap junctions forming an important type of intercellular communication. In this cellular model, two complementary assays have been established for detection of the modes of action associated with tumor promotion: inhibition of gap junctional intercellular communication (GJIC) and proliferative activity in confluent cells. We found that the PAHs and PCBs, which are AhR agonists, released WB-F344 cells from contact inhibition, increasing both DNA synthesis and cell numbers. Genotoxic effects of some PAHs that lead to apoptosis and cell cycle delay might interfere with the proliferative activity of PAHs. Contrary to that, the nongenotoxic low-molecular-weight PAHs and non-dioxin-like PCB congeners, abundant in the environment, did not significantly affect cell cycle and cell proliferation; however both groups of compounds inhibited GJIC in WB-F344 cells. The release from contact inhibiton by a mechanism that possibly involves the AhR activation, inhibition of GJIC and genotoxic events induced by environmental contaminants are three important modes of action that could play an important role in carcinogenic effects of toxic compounds. The relative potencies to inhibit GJIC, to induce AhR-mediated activity, and to release cells from contact inhibition were determined for a large series of PAHs and PCBs and their metabolites. In vitro bioassays based on detection of events on cellular level (deregulation of GJIC and/or proliferation) or determination of receptor-mediated activities in both ?$stem-like^{\circ}{\times}$ and hepatocyte-like liver cellular models are valuable tools for detection of modes of action of polyaromatic hydrocarbons. They may serve, together with concentration data, as a first step in their risk assessment.

• Biomolecules & Therapeutics
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• v.31 no.2
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• pp.161-167
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• 2023

Despite the various medications used in clinics, the efforts to develop more effective treatments for depression continue to increase in the past decades mainly because of the treatment-resistant population, and the testing of several hypotheses- and target-based treatments. Undesirable side effects and unresponsiveness to current medications fuel the drive to solve this top global health problem. In this study, we focused on neuroinflammatory response-mediated depression which represents a cluster of depression etiology both in animal models and humans. Several meta-analyses reported that proinflammatory cytokines such as interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) were increased in major depressive disorder patients. Inflammatory mediators implicated in depression include type-I interferon and inflammasome pathways. To elucidate the molecular mechanisms of neuroinflammatory cascades underlying the pathophysiology of depression, we introduced hycanthone, an antischistosomal drug, to check whether it can counteract depressive-like behaviors in vivo and normalize the inflammation-induced changes in vitro. Lipopolysaccharide (LPS) treatment increased proinflammatory cytokine expression in the murine microglial cells as well as the stimulation of type I interferon-related pathways that are directly or indirectly regulated by Janus kinase-signal transducer and activator of transcription (JAK-STAT) activation. Hycanthone treatment attenuated those changes possibly by inhibiting the JAK-STAT pathway and inflammasome activation. Hycanthone also ameliorated depressive-like behaviors by LPS. Taken together, we suggest that the inhibitory action of hycanthone against the interferon pathway leading to attenuation of depressive-like behaviors can be a novel therapeutic mechanism for treating depression.

• Biomolecules & Therapeutics
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• v.31 no.4
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• pp.434-445
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• 2023

We investigated whether FTY-720 might have an effect on bleomycin-induced pulmonary fibrosis through inhibiting TGF-β1 pathway, and up-regulating autophagy. The pulmonary fibrosis was induced by bleomycin. FTY-720 (1 mg/kg) drug was intraperitoneally injected into mice. Histological changes and inflammatory factors were observed, and EMT and autophagy protein markers were studied by immunohistochemistry and immunofluorescence. The effects of bleomycin on MLE-12 cells were detected by MTT assay and flow cytometry, and the related molecular mechanisms were studied by Western Blot. FTY-720 considerably attenuated bleomycin-induced disorganization of alveolar tissue, extracellular collagen deposition, and α-SMA and E-cadherin levels in mice. The levels of IL-1β, TNF-α, and IL-6 cytokines were attenuated in bronchoalveolar lavage fluid, as well as protein content and leukocyte count. COL1A1 and MMP9 protein expressions in lung tissue were significantly reduced. Additionally, FTY-720 treatment effectively inhibited the expressions of key proteins in TGF-β1/TAK1/P38MAPK pathway and regulated autophagy proteins. Similar results were additionally found in cellular assays with mouse alveolar epithelial cells. Our study provides proof for a new mechanism for FTY-720 to suppress pulmonary fibrosis. FTY-720 is also a target for treating pulmonary fibrosis.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.10
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• pp.4353-4358
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• 2014

Background: PI3/AKT and NF-kB signaling pathways are constitutively active in acute myeloid leukemia and cross-talk between the two has been shown in various cancers. However, their role in acute myeloid leukemia has not been completely explored. We therefore used cell penetrating inhibitor peptides to define the contributions of AKT and NF-kB to survival and multi drug resistance (MDR) in HL-60 cells. Materials and Methods: Inhibition of AKT and NF-kB activity by AKT inhibitor peptide and NBD inhibitor peptide, respectively, resulted in decreased expression of mRNA for the MDR1 gene as assessed by real time PCR. In addition, treatment of HL-60 cells with AKT and NBD inhibitor peptides led to inhibition of cell viability and induction of apoptosis in a dose dependent manner as detected by flow cytometer. Results: Finally, co-treatment of HL-60 cells with sub-optimal doses of AKT and NBD inhibitor peptides led to synergistic apoptotic responses in AML cells. Conclusions: These data support a strong biological link between NF-kB and PI3-kinase/AKT pathways in the modulation of antiapoptotic and multi drug resistant effects in AML cells. Synergistic targeting of these pathways using NF-kB and PI3-kinase/AK inhibitor peptides may have a therapeutic potential for AML and possibly other malignancies with constitutive activation of these pathways.

• Parasites, Hosts and Diseases
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• v.54 no.6
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• pp.759-768
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• 2016

Cystic echinococcosis (CE) treatment urgently requires a novel drug. The p38 mitogen-activated protein kinases (MAPKs) are a family of Ser/Thr protein kinases, but still have to be characterized in Echinococcus granulosus. We identified a 1,107 bp cDNA encoding a 368 amino acid MAPK protein (Egp38) in E. granulosus. Egp38 exhibits 2 distinguishing features of p38-like kinases: a highly conserved T-X-Y motif and an activation loop segment. Structural homology modeling indicated a conserved structure among Egp38, EmMPK2, and H. sapiens $p38{\alpha}$, implying a common binding mechanism for the ligand domain and downstream signal transduction processing similar to that described for $p38{\alpha}$. Egp38 and its phosphorylated form are expressed in the E. granulosus larval stages vesicle and protoscolices during intermediate host infection of an intermediate host. Treatment of in vitro cultivated protoscolices with the p38-MAPK inhibitor ML3403 effectively suppressed Egp38 activity and led to significant protoscolices death within 5 days. Treatment of in vitro-cultivated protoscolices with $TGF-{\beta}1$ effectively induced Egp38 phosphorylation. In summary, the MAPK, Egp38, was identified in E. granulosus, as an anti-CE drug target and participates in the interplay between the host and E. granulosus via human $TGF-{\beta}1$.

• BMB Reports
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• v.40 no.6
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• pp.911-920
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• 2007

Tuberculosis, caused by Mycobacterium tuberculosis, continues to be one of the leading infectious diseases to humans. It is urgent to discover novel drug targets for the development of antitubercular agents. The 2-C-methyl-Derythritol-4-phosphate (MEP) pathway for isoprenoid biosynthesis has been considered as an attractive target for the discovery of novel antibiotics for its essentiality in bacteria and absence in mammals. MEP cytidyltransferase (IspD), the third-step enzyme of the pathway, catalyzes MEP and CTP to form 4-diphosphocytidyl-2-C-methylerythritol (CDP-ME) and PPi. In the work, ispD gene from M. tuberculosis H37Rv (MtIspD) was cloned and expressed. With N-terminal fusion of a histidine-tagged sequence, MtIspD could be purified to homogeneity by one-step nickel affinity chromatography. MtIspD exists as a homodimer with an apparent molecular mass of 52 kDa. Enzyme property analysis revealed that MtIspD has high specificity for pyrimidine bases and narrow divalent cation requirements, with maximal activity found in the presence of CTP and $Mg^{2+}$. The turnover number of MtIspD is $3.4 s^{-1}$. The Km for MEP and CTP are 43 and $92{\mu}M$, respectively. Furthermore, MtIspD shows thermal instable above $50^{\circ}C$. Circular dichroism spectra revealed that the alteration of tertiary conformation is closely related with sharp loss of enzyme activity at higher temperature. This study is expected to help better understand the features of IspD and provide useful information for the development of novel antibiotics to treat M. tuberculosis.

• Biomolecules & Therapeutics
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• v.30 no.3
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• pp.274-283
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• 2022

KRAS activating mutations, which are present in more than 90% of pancreatic cancers, drive tumor dependency on the RAS/mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/AKT signaling pathways. Therefore, combined targeting of RAS/MAPK and PI3K/AKT signaling pathways may be required for optimal therapeutic effect in pancreatic cancer. However, the therapeutic efficacy of combined MAPK and PI3K/AKT signaling target inhibitors is unsatisfactory in pancreatic cancer treatment, because it is often accompanied by MAPK pathway reactivation by PI3K/AKT inhibitor. Therefore, we developed an inRas37 antibody, which directly targets the intra-cellularly activated GTP-bound form of oncogenic RAS mutation and investigated its synergistic effect in the presence of the PI3K inhibitor BEZ-235 in pancreatic cancer. In this study, inRas37 remarkably increased the drug response of BEZ-235 to pancreatic cancer cells by inhibiting MAPK reactivation. Moreover, the co-treatment synergistically inhibited cell proliferation, migration, and invasion and exhibited synergistic anticancer activity by inhibiting the MAPK and PI3K pathways. The combined administration of inRas37and BEZ-235 significantly inhibited tumor growth in mouse models. Our results demonstrated that inRas37 synergistically increased the antitumor activity of BEZ-235 by inhibiting MAPK reactivation, suggesting that inRas37 and BEZ-235 co-treatment could be a potential treatment approach for pancreatic cancer patients with KRAS mutations.

• Journal of Ginseng Research
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• v.48 no.1
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• pp.77-88
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• 2024

Background: Lung inflammation occurs in many lung diseases, but has limited effective therapeutics. Ginseng and its derivatives have anti-inflammatory effects, but their unstable physicochemical and metabolic properties hinder their application in the treatment. Panaxadiol (PD) is a stable saponin among ginsenosides. Inhalation administration may solve these issues, and the specific mechanism of action needs to be studied. Methods: A mouse model of lung inflammation induced by lipopolysaccharide (LPS), an in vitro macrophage inflammation model, and a coculture model of epithelial cells and macrophages were used to study the effects and mechanisms of inhalation delivery of PD. Pathology and molecular assessments were used to evaluate efficacy. Transcriptome sequencing was used to screen the mechanism and target. Finally, the efficacy and mechanism were verified in a human BALF cell model. Results: Inhaled PD reduced LPS-induced lung inflammation in mice in a dose-dependent manner, including inflammatory cell infiltration, lung tissue pathology, and inflammatory factor expression. Meanwhile, the dose of inhalation was much lower than that of intragastric administration under the same therapeutic effect, which may be related to its higher bioavailability and superior pharmacokinetic parameters. Using transcriptome analysis and verification by a coculture model of macrophage and epithelial cells, we found that PD may act by inhibiting TNFA/TNFAR and IL7/IL7R signaling to reduce macrophage inflammatory factor-induced epithelial apoptosis and promote proliferation. Conclusion: PD inhalation alleviates lung inflammation and pathology by inhibiting TNFA/TNFAR and IL7/IL7R signaling between macrophages and epithelial cells. PD may be a novel drug for the clinical treatment of lung inflammation.

• Molecules and Cells
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• v.43 no.11
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• pp.909-920
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• 2020

Cytosolic Ca²⁺ levels ([Ca²⁺]_c) change dynamically in response to inducers, repressors, and physiological conditions, and aberrant [Ca²⁺]_c concentration regulation is associated with cancer, heart failure, and diabetes. Therefore, [Ca²⁺]_c is considered as a good indicator of physiological and pathological cellular responses, and is a crucial biomarker for drug discovery. A genetically encoded calcium indicator (GECI) was recently developed to measure [Ca²⁺]_c in single cells and animal models. GECI have some advantages over chemically synthesized indicators, although they also have some drawbacks such as poor signal-to-noise ratio (SNR), low positive signal, delayed response, artifactual responses due to protein overexpression, and expensive detection equipment. Here, we developed an indicator based on interactions between Ca²⁺-loaded calmodulin and target proteins, and generated an innovative GECI sensor using split nano-luciferase (Nluc) fragments to detect changes in [Ca²⁺]_c. Stimulation-dependent luciferase activities were optimized by combining large and small subunits of Nluc binary technology (NanoBiT, LgBiT:SmBiT) fusion proteins and regulating the receptor expression levels. We constructed the binary [Ca²⁺]_c sensors using a multicistronic expression system in a single vector linked via the internal ribosome entry site (IRES), and examined the detection efficiencies. Promoter optimization studies indicated that promoter-dependent protein expression levels were crucial to optimize SNR and sensitivity. This novel [Ca²⁺]_c assay has high SNR and sensitivity, is easy to use, suitable for high-throughput assays, and may be useful to detect [Ca²⁺]_c in single cells and animal models.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5339-5343
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• 2012

The induction of apoptosis in target cells is a key mechanism for most anti-tumor therapies. Bufalin is a cardiotonic steroid that has the potential to induce differentiation and apoptosis of tumor cells. Research on bufalin has so far mainly involved leukemia, prostate cancer, gastric cancer and liver cancer, and has been confined to in vitro studies. The bufadienolides bufalin and cinobufagin have been shown to induce apoptosis in a wide spectrum of cancer cell. The present article reviews the anticancer effects of bufalin. It induces apoptosis of lung cancer cells via the PI3K/Akt pathway and also suppressed the proliferation of human non-small cell lung cancer A549 cell line in a time and dose dependent manner. Bufalin, bufotalin and gamabufotalin, key bufadienolides, significantly sensitize human breast cancer cells with differing ER-alpha status to apoptosis induction by the TNF-related apoptosis-inducing ligand (TRAIL). In addition, bufadienolides induce prostate cancer cell apoptosis more significantly than that in breast epithelial cell lines. Similar effects have been observed with hepatocellular carcinoma (HCC) but the detailed molecular mechanisms of inducing apoptosis in this case are still unclear. Bufalin exerts profound effects on leukemia therapy in vitro. Results of multiple studies indicate that bufalin has marked anti-tumor activities through its ability to induce apoptosis. Large-scale randomized, double-blind, placebo or positive drug parallel controlled studies are now required to confirm the efficacy and apoptosis-inducing potential of bufalin in various cancers in the cliniucal setting.