A cytokinin response factor PtCRF1 is involved in the regulation of wood formation in poplar.

Wood formation is a complex developmental process under the control of multiple levels of regulatory transcriptional network and hormone signals in trees. It is well known that cytokinin (CK) signaling plays an important role in maintaining the activity of the vascular cambium. The CK response factors (CRFs) encoding a subgroup of AP2 transcription factors have been identified to mediate the CK-dependent regulation in different plant developmental processes. However, the functions of CRFs in wood development remain unclear. Here, we characterized the function of PtCRF1, a CRF transcription factor isolated from poplar, in the process of wood formation. The PtCRF1 is preferentially expressed in secondary vasculature, especially in vascular cambium and secondary phloem, and encodes a transcriptional activator. Overexpression of PtCRF1 in transgenic poplar plants led to a significant reduction in the cell layer number of vascular cambium. The development of wood tissue was largely promoted in the PtCRF1-overexpressing lines, while it was significantly compromised in the CRISPR/Cas9-generated double mutant plants of PtCRF1 and its closest homolog PtCRF2. The RNA sequencing (RNA-seq) and quantitative reverse transcription PCR (RT-qPCR) analyses showed that PtCRF1 repressed the expression of the typical CK-responsive genes. Furthermore, bimolecular fluorescence complementation assays revealed that PtCRF1 competitively inhibits the direct interactions between histidine phosphotransfer proteins and type-B response regulator by binding to PtHP protein. Collectively, these results indicate that PtCRF1 negatively regulates CK signaling and is required for woody cell differentiation in poplar.

Delayed CO2 postconditioning promotes neurological recovery after cryogenic traumatic brain injury by downregulating IRF7 expression.

AIMS: Few treatments are available in the subacute phase of traumatic brain injury (TBI) except rehabilitation training. We previously reported that transient CO2 inhalation applied within minutes after reperfusion has neuroprotective effects against cerebral ischemia/reperfusion injury. In this study, it was hypothesized that delayed CO2 postconditioning (DCPC) starting at the subacute phase may promote neurological recovery of TBI. METHODS: Using a cryogenic TBI (cTBI) model, mice received DCPC daily by inhaling 5%/10%/20% CO2 for various time-courses (one/two/three cycles of 10-min inhalation/10-min break) at Days 3-7, 3-14 or 7-18 after cTBI. Beam walking and gait tests were used to assess the effect of DCPC. Lesion size, expression of GAP-43 and synaptophysin, amoeboid microglia number and glia scar area were detected. Transcriptome and recombinant interferon regulatory factor 7 (Irf7) adeno-associated virus were applied to investigate the molecular mechanisms. RESULTS: DCPC significantly promoted recovery of motor function in a concentration and time-course dependent manner with a wide therapeutic time window of at least 7 days after cTBI. The beneficial effects of DCPC were blocked by intracerebroventricular injection of NaHCO3 . DCPC also increased puncta density of GAP-43 and synaptophysin, and reduced amoeboid microglia number and glial scar formation in the cortex surrounding the lesion. Transcriptome analysis showed many inflammation-related genes and pathways were altered by DCPC, and Irf7 was a hub gene, while overexpression of IRF7 blocked the motor function improvement of DCPC. CONCLUSIONS: We first showed that DCPC promoted functional recovery and brain tissue repair, which opens a new therapeutic time window of postconditioning for TBI. Inhibition of IRF7 is a key molecular mechanism for the beneficial effects of DCPC, and IRF7 may be a potential therapeutic target for rehabilitation after TBI.

Unusual presentation of systemic lupus erythematosus as hemophagocytic lymphohistiocytosis in a female patient: A case report.

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) is a rare life-threatening disorder, often resulting in the immune-mediated injury of multiple organ systems, including primary HLH and secondary HLH (sHLH). Among them, sHLH results from infections, malignant, or autoimmune conditions, which have quite poor outcomes even with aggressive management and are more common in adults. CASE SUMMARY: We report a rare case of a 36-year-old female manifested with sHLH on background with systemic lupus erythematosus (SLE). During hospitalization, the patient was characterized by recurrent high-grade fever, petechiae and ecchymoses of abdominal skin, and pulmonary infection. Whole exon gene sequencing revealed decreased activity of natural killer cells. She received systematic treatment with Methylprednisolone, Etoposide, and anti-infective drugs. Intravenous immunoglobulin and plasmapheresis were applied when the condition was extremely acute and progressive. The patient recovered and did not present any relapse of the HLH for one year of follow-up. CONCLUSION: The case showed sHLH, thrombotic microvascular, and infection in the whole course of the disease, which was rarely reported by now. The treatment of the patient emphasizes that early recognition and treatment of sHLH in SLE patients was of utmost importance to improve the prognosis and survival rate of patients.

Edema of limbs as the primary symptom of gastric signet-ring cell carcinoma: A case report and literature review.

BACKGROUND: Metastatic skin cancers are relatively rare dermatological malignancies. They usually present as nodules, erythematous lesions, scar-like lesions or other lesion types. Signet-ring cell carcinoma (SRCC) is an uncommon histological type of gastric cancer that usually behaves aggressively and has a poor prognosis. Skin metastasis may be the first sign of clinically silent visceral cancer or recurrence of an internal malignancy. CASE SUMMARY: Herein we report on the case of a 55-year-old man with edema of a lower extremity as the primary symptom which progressed from local to generalized pitting edema in the year following skin involvement. Pathological evidence from gastroscopic specimens and subcutaneous tissue biopsy showed typical signet-ring cells and gland-like structures. Consistently, immunohistochemical analysis revealed positive pan-cytokeratin expression in tumor cells. A diagnosis of gastric SRCC with skin metastasis was established. Moreover, lymphoscintigraphy showed an obvious accumulation of radiotracer on the anterior and posterior sides of the right leg which indicated lymphedema. We reviewed the relevant literature on subcutaneous metastases of gastric SRCC. CONCLUSION: This rare case emphasizes the importance of physical examination as it may help elucidate the etiology of edema.

Sphingosine-1-Phosphate Protects Against the Development of Cardiac Remodeling via Sphingosine Kinase 2 and the S1PR2/ERK Pathway.

OBJECTIVE: Cardiac remodeling is a common pathological change in various cardiovascular diseases and can ultimately result in heart failure. Thus, there is an urgent need for more effective strategies to aid in cardiac protection. Our previous work found that sphingosine-1-phosphate (S1P) could ameliorate cardiac hypertrophy. In this study, we aimed to investigate whether S1P could prevent cardiac fibrosis and the associated mechanisms in cardiac remodeling. METHODS: Eight-week-old male C57BL/6 mice were randomly divided into a sham, transverse aortic constriction (TAC) or a TAC+S1P treatment group. RESULTS: We found that S1P treatment improved cardiac function in TAC mice and that the cardiac fibrosis ratio in the TAC+S1P group was significantly lower and was accompanied by a decrease in α-smooth muscle actin (α-SMA) and collagen type I (COL I) expression compared with the TAC group. We also found that one of the key S1P enzymes, sphingosine kinase 2 (SphK2), which was mainly distributed in cytoblasts, was downregulated in the cardiac remodeling case and recovered after S1P treatment in vivo and in vitro. In addition, our in vitro results showed that S1P treatment activated extracellular regulated protein kinases (ERK) phosphorylation mainly through the S1P receptor 2 (S1PR2) and spurred p-ERK transposition from the cytoplasm to cytoblast in H9c2 cells exposed to phenylephrine. CONCLUSION: These findings suggest that SphK2 and the S1PR2/ERK pathway may participate in the anti-remodeling effect of S1P on the heart. This work therefore uncovers a novel potential therapy for the prevention of cardiac remodeling.

2-(Naphthalene-2-thio)-5,8-dimethoxy-1,4-naphthoquinone induces apoptosis via ROS-mediated MAPK, AKT, and STAT3 signaling pathways in HepG2 human hepatocellular carcinoma cells.

1,4-naphthoquinone and its derivatives have attracted widespread attention due to their multiple biological activities, such as induction of cancer cell apoptosis; however, most of these compounds have high cytotoxicity. In this study, in order to reduce their toxicity and increase their potential anti-tumor effects, we synthesized a novel 1,4-naphthoquinone derivative named 2-(naphthalene-2-thio)-5,8-dimethoxy-1,4-naphthoquinone (NTDMNQ), and investigated its apoptotic effects and underlying mechanism. Our results showed that NTDMNQ inhibited the viability of HepG2, Hep3B, and Huh7 human hepatocellular carcinoma (HCC) cells. It also increased the accumulation of cells in the G0/G1 phase of the cell cycle by increasing the expression levels of p-p53, p21 and p27, while decreasing the levels of Cyclin D1, Cyclin E, Cyclin-dependent kinase 2 (CDK2), CDK4, and CDK6. Inhibition of reactive oxygen species (ROS) by the ROS scavenger N-acetyl-L-cysteine (NAC) decreased apoptosis in NTDMNQ-treated cells. Western blot analysis showed that NTDMNQ increased the phosphorylation of p38 and c-Jun N-terminal kinase (JNK), and decreased the phosphorylation of extracellular signal-regulated kinase (ERK), AKT, and signal transducer and activator of transcription-3 (STAT3); these effects were blocked by NAC. Both the JNK inhibitor (SP600125) and p38 inhibitor (SB203580) reversed the phosphorylation of STAT3, and the ERK inhibitor (FR180204) and AKT inhibitor (LY294002) reduced the expression of STAT3. Taken together, these findings suggest that NTDMNQ induces apoptosis via ROS-mediated MAPK, AKT and STAT3 signaling pathways in HepG2 cells, and may be a potent anticancer agent.

Posterior reversible encephalopathy syndrome with a special focus on seizures.

Posterior reversible encephalopathy syndrome (PRES) is a neurological disorder characterized by headache, seizures, confusion and visual disturbances, as well as potentially reversible neuroimaging findings in most patients after proper treatment. Seizures is one of the most common clinical presentations of PRES. This review summarizes the potential pathophysiology and clinical features of PRES, as well as a multimodal approach to imaging and also briefly discusses the phenomenon of seizures in paediatric population.

The compound 2-benzylthio-5,8-dimethoxynaphthalene-1,4-dione leads to apoptotic cell death by increasing the cellular reactive oxygen species levels in Ras-mutated liver cancer cells.

The aim of the present study was to verify the pro-apoptotic anticancer potential of several 5,8-dimethoxy-1,4-phthoquinone (DMNQ) derivatives in Ras-mediated tumorigenesis. MTT assays were used to detect cellular viability and flow cytometry was performed to assess intracellular reactive oxygen species (ROS) levels and apoptosis. The expression levels of proteins were detected via western blotting. Among the 12 newly synthesized DMNQ derivatives, 2-benzylthio-5,8-dimethoxynaphthalene-1,4-dione (BZNQ; component #1) significantly reduced cell viability both in mouse NIH3T3 embryonic fibroblasts cells (NC) and H-RasG12V transfected mouse NIH3T3 embryonic fibroblasts cells (NR). Moreover, BZNQ resulted in increased cytotoxic sensitivity in Ras-mutant transfected cells. Furthermore, the reactive oxygen species (ROS) levels in H-RasG12V transfected HepG2 liver cancer cells (HR) were significantly higher compared with the levels in HepG2 liver cancer cells (HC) following BZNQ treatment, which further resulted in increased cellular apoptosis. Eliminating cellular ROS using an ROS scavenger N-acetyl-L-cysteine markedly reversed BZNQ-induced cellular ROS accumulation and cell apoptosis in HC and HR cells. Western blotting results revealed that BZNQ significantly downregulated H-Ras protein expression and inhibited the Ras-mediated downstream signaling pathways such as protein kinase B, extracellular signal-related kinase and glycogen synthase kinase phosphorylation and ß-catenin protein expression. These results indicated that the novel DMNQ derivative BZNQ may be a therapeutic drug for Ras-mediated liver tumorigenesis. The results of the current study suggest that BZNQ exerts its effect by downregulating H-Ras protein expression and Ras-mediated signaling pathways.

2-(6-Hydroxyhexylthio)-5,8-dimethoxy-1,4-naphthoquinone Induces Apoptosis through ROS-Mediated MAPK, STAT3, and NF-κB Signalling Pathways in Lung Cancer A549 Cells.

Two novel compounds, 2-(2-hydroxyethylthio)-5,8-dimethoxy-1,4-naphthoquinone (HEDMNQ) and 2-(6-hydroxyhexylthio)-5,8-dimethoxy-1,4-naphthoquinone (HHDMNQ), were synthesized to investigate the kill effects and mechanism of 1,4-naphthoquinone derivatives in lung cancer cells. The results of the CCK-8 assay showed that HEDMNQ and HHDMNQ had significant cytotoxic effects on A549, NCI-H23, and NCI-H460 NSCLC cells. Flow cytometry and western blot results indicated that HHDMNQ induced A549 cell cycle arrest at the G2/M phase by decreasing the expression levels of cyclin-dependent kinase 1/2 and cyclin B1. Fluorescence microscopy and flow cytometry results indicated that HHDMNQ could induce A549 cell apoptosis, and western blot analysis showed that HHDMNQ induced apoptosis through regulating the mitochondria pathway, as well as the MAPK, STAT3, and NF-κB signalling pathways. Flow cytometry results showed that intracellular reactive oxygen species (ROS) levels were increased after HHDMNQ treatment, and western blot showed that ROS could modulate the intrinsic pathway and MAPK, STAT3, and NF-κB signalling pathways. These effects were blocked by the ROS inhibitor N-acetyl-L-cysteine in A549 cells. Our findings suggest that compared with HEDMNQ, HHDMNQ had the stronger ability to inhibit the cell viability of lung cancer cells and induce apoptosis by regulating the ROS-mediated intrinsic pathway and MAPK/STAT3/NF-κB signalling pathways. Thus, HHDMNQ might be a potential antitumour compound for treating lung cancer.

Picrasma quassioides Extract Elevates the Cervical Cancer Cell Apoptosis Through ROS-Mitochondrial Axis Activated p38 MAPK Signaling Pathway.

BACKGROUND/AIM: Picrasma quassioides (P. quassioides) is used in traditional Asian medicine widely for the treatment of anemopyretic cold, eczema, nausea, loss of appetite, diabetes mellitus, hypertension etc. In this study we aimed to understand the effect of P. quassioides ethanol extract on SiHa cervical cancer cell apoptosis. MATERIALS AND METHODS: The P. quassioides extract-induced apoptosis was analyzed using the MTT assay, fluorescence microscopy, flow cytometry and western blotting. RESULTS: P. quassioides extract induced cellular apoptosis by increasing the accumulation of cellular and mitochondrial reactive oxygen species (ROS) levels and inhibiting ATP synthesis. Pretreatment with N-Acetylcysteine (NAC), a classic antioxidant, decreased the intracellular ROS production and inhibited apoptosis. In addition, the P38 MAPK signaling pathway is a key in the apoptosis of SiHa cells induced by the P. quassioides extract. CONCLUSION: The P. quassioides extract exerts its anti-cancer properties on SiHa cells through ROS-mitochondria axis and P38 MAPK signaling. Our data provide a new insight for P. quassioides as a therapeutic strategy for cervical cancer treatment.

Isoorientin induces the apoptosis and cell cycle arrest of A549 human lung cancer cells via the ROS­regulated MAPK, STAT3 and NF­κB signaling pathways.

Isoorientin (ISO) is a naturally occurring C­glycosyl flavone that has various pharmacological properties, such as anti­bacterial and anti­inflammatory effects. However, its underlying molecular mechanisms in human lung cancer cells remain unknown. In the present study, the effects of ISO on the induction of apoptosis and relative molecular mechanisms in A549 human lung cancer cells were investigated. The results of Cell Counting Kit­8 assay (CCK­8) indicated that ISO exerted significant cytotoxic effects on 3 lung cancer cell lines, but had no obvious side­effects on normal cells. Moreover, flow cytometry and western blot analysis revealed that ISO induced mitochondrial­dependent apoptosis by reducing mitochondrial membrane potential. ISO also increased the expression levels of Bax, cleaved­caspase­3 (cle­cas­3) and poly(ADP­ribose) polymerase (PARP; cle­PARP), and decreased the expression levels of Bcl­2 in A549 cells. Furthermore, ISO induced G2/M cell cycle arrest by decreasing the expression levels of cyclin B1 and CDK1/2, and increasing the expression levels of p21 and p27 in A549 cells. As the duration of ISO treatment increased, intracellular reactive oxygen species (ROS) levels in A549 cells also increased. However, pre­treatment of the cells with the ROS scavenger, N­acetylcysteine (NAC), inhibited ISO­induced apoptosis. In addition, ISO increased the expression levels of p­p38, p­JNK and IκB­α; and decreased the expression levels of p­extracellular signal­regulated kinase (ERK), p­signal transducer and activator of transcription (STAT)3, p­nuclear factor (NF)­κB, NF­κB and p­IκB; these effects were induced by mitogen­activated protein kinase (MAPK) inhibitors and blocked by NAC. Taken together, the results of the present study indicate that ISO induces the apoptosis of A549 lung cancer cells via the ROS­mediated MAPK/STAT3/NF­κB signaling pathway, and thus may be a potential drug for use in the treatment of lung cancer.

Peroxiredoxin I deficiency increases pancreatic ß­cell apoptosis after streptozotocin stimulation via the AKT/GSK3ß signaling pathway.

Apoptosis of pancreatic ß­cells is involved in the pathogenesis of type I and II diabetes. Peroxiredoxin I (Prx I) serves an important role in regulating cellular apoptosis; however, the role of Prx I in pancreatic ß­cell apoptosis is not completely understood. In the present study, the role of peroxiredoxin 1 (Prx I) during streptozotocin (STZ)­induced apoptosis of pancreatic ß­cells was investigated. The expression level of Prx I was decreased by STZ treatment in a time­dependent manner, and apoptosis of Prx I knockdown MIN6 cells was increased by STZ stimulation, compared with untransduced MIN6 cells. Furthermore, an intraperitoneal injection of STZ increased pancreatic islet damage in Prx I knockout mice, compared with wild­type and Prx II knockout mice. AKT and glycogen synthase kinase (GSK)­3ß phosphorylation significantly decreased following Prx I knockdown in MIN6 cells. However, phosphorylated ß­catenin and p65 levels significantly increased after STZ stimulation, compared with untransduced cells. The results of the present study indicate that deletion of Prx I mediated STZ­induced pancreatic ß­cell death in vivo and in vitro by regulating the AKT/GSK­3ß/ß­catenin signaling pathway, as well as NF­κB signaling. These findings provide a theoretical basis for treatment of pancreatic damage.

Peroxiredoxin II Maintains the Mitochondrial Membrane Potential against Alcohol-Induced Apoptosis in HT22 Cells.

Excessive alcohol intake can significantly reduce cognitive function and cause irreversible learning and memory disorders. The brain is particularly vulnerable to alcohol-induced ROS damage; the hippocampus is one of the most sensitive areas of the brain for alcohol neurotoxicity. In the present study, we observed significant increasing of intracellular ROS accumulations in Peroxiredoxin II (Prx II) knockdown HT22 cells, which were induced by alcohol treatments. We also found that the level of ROS in mitochondrial was also increased, resulting in a decrease in the mitochondrial membrane potential. The phosphorylation of GSK3ß (Ser9) and anti-apoptotic protein Bcl2 expression levels were significantly downregulated in Prx II knockdown HT22 cells, which suggests that Prx II knockdown HT22 cells were more susceptible to alcohol-induced apoptosis. Scavenging the alcohol-induced ROS with NAC significantly decreased the intracellular ROS levels, as well as the phosphorylation level of GSK3ß in Prx II knockdown HT22 cells. Moreover, NAC treatment also dramatically restored the mitochondrial membrane potential and the cellular apoptosis in Prx II knockdown HT22 cells. Our findings suggest that Prx II plays a crucial role in alcohol-induced neuronal cell apoptosis by regulating the cellular ROS levels, especially through regulating the ROS-dependent mitochondrial membrane potential. Consequently, Prx II may be a therapeutic target molecule for alcohol-induced neuronal cell death, which is closely related to ROS-dependent mitochondria dysfunction.

Integrated network analysis to explore the key mRNAs and lncRNAs in acute myocardial infarction.

Acute myocardial infarction (AMI) is the most severe cardiovascular event in the world. However, the molecular mechanisms underlying AMI remained largely unclear. Recently, long non-coding RNAs (lncRNAs) were reported to play important roles in human diseases. In the present work, we analyzed a public dataset GSE48060 to confirm key lncRNAs and mRNAs in AMI. We observed 4835 mRNAs and 442 lncRNAs were significantly differently expressed in AMI. Then, we for the first time constructed PPI networks and lncRNA co-expression networks in AMI. The protein-protein interaction (PPI) networks revealed several mRNAs such as RHOA, GNB1, GNG, RAC1, FBXO32, DET1, MEX3C and HECTD1 functioned as key regulators in AMI. LncRNA co-expression network analysis showed 8 lncRNAs (CA5BP1, LOC101927608, BZRAP1-AS1, EBLN3, FGD5-AS1, HNRNPU-AS1, LINC00342, and LOC101927204) played key roles in AMI. Gene ontology (GO) analysis demonstrated these differently expressed lncRNAs were associated with more signaling pathways, such as regulating transcription, protein amino acid phosphorylation, signal transduction, development. Taken together, our research unveiled a series of key lncRNAs and mRNAs in AMI. Several lncRNAs, including CA5BP1, LOC101927608, BZRAP1-AS1, EBLN3, FGD5-AS1, HNRNPU-AS1, LINC00342, and LOC101927204 were identified as key lncRNAs. PPI networks were constructed to reveal key mRNAs in AMI. These results provided useful information for exploring novel molecular target therapy for AMI.

KLB gene polymorphism is associated with obesity and non-alcoholic fatty liver disease in the Han Chinese.

Klotho beta (KLB) mediates binding of fibroblast growth factor (FGF) 21 to the FGF receptor (FGFR). FGF21-KLB-FGFR signaling regulates multiple metabolic systems in the liver, and we hypothesized that FGF21, KLB and FGFR single-nucleotide polymorphisms (SNPs) are involved in hepatic lipid accumulation. The SNPs were detected in 1688 individuals divided into four groups: non-obese without non-alcoholic fatty liver disease (NAFLD), obese without NAFLD, non-obese with NAFLD, and obese with NAFLD. The A-allele of KLB SNP rs7670903 correlated with higher body mass index (P = 0.0005), and the A-allele frequency was higher in the obese than non-obese group (P = 0.003). The G-allele frequency of KLB rs7674434 and T-allele frequency of rs12152703 were higher in the obese with NAFLD than obese without NAFLD group (P = 0.004 and P = 0.006), but the genotype distribution between two non-obese groups did not differ. KLB rs7674434 and rs12152703 had associations with alanine aminotransferase (ALT) (P = 0.03 and P = 0.04, respectively) and gamma-glutamyltransferase (P = 0.03 and P = 0.02, respectively) levels in all subjects, but the associations were especially strong with ALT in the NAFLD group (P = 0.005 and P = 0.008, respectively). These findings suggest that KLB SNPs are related to obesity and hepatic inflammation and that they may be involved in the pathogenesis of NAFLD.

Peroxiredoxin V Inhibits Emodin-induced Gastric Cancer Cell Apoptosis via the ROS/Bcl2 Pathway.

BACKGROUND/AIM: Peroxiredoxin (Prx) protein family is aberrantly expressed in various cancers including gastric cancer. Among the six family members, Prx V has been known as an antioxidant enzyme which scavenges intracellular reactive oxygen species (ROS) and modulates cellular apoptosis. This study aimed at investigating the role of Prx V in apoptosis of gastric cancer cells. MATERIALS AND METHODS: Stably constructed Prx V knockdown, over-expression and mock AGS cells (a human gastric adenocarcinoma cell line) were used to study the effect of Prx V on emodin-induced apoptosis by western blotting, cell viability, apoptosis and ROS detection assays. RESULTS: Overexpression of Prx V significantly decreased emodin-induced cellular apoptosis and ROS levels compared to Mock and Prx V knockdown AGS cells. Also, overexpression of Prx V down-regulated the expression of pro-apoptotic proteins, Bad and cleaved PARP, and increased the expression of anti-apoptotic protein, Bcl2. CONCLUSION: Prx V suppresses AGS cell apoptosis via scavenging intracellular ROS and modulating apoptosis-related markers.

Two novel 1,4­naphthoquinone derivatives induce human gastric cancer cell apoptosis and cell cycle arrest by regulating reactive oxygen species­mediated MAPK/Akt/STAT3 signaling pathways.

1,4­Naphthoquinone derivatives have superior anticancer effects, but their use has been severely limited in clinical practice due to adverse side effects. To reduce the side effects and extend the anticancer effects of 1,4­naphthoquinone derivatives, 2­(butane­1­sulfinyl)­1,4­naphthoquinone (BQ) and 2­(octane­1­sulfinyl)­1,4­naphthoquinone (OQ) were synthesized, and their anticancer activities were investigated. The anti­proliferation effects, determined by MTT assays, showed that BQ and OQ significantly inhibited the viability of gastric cancer cells and had no significant cytotoxic effect on normal cell lines. The apoptotic effect was determined by flow cytometry, and the results showed that BQ and OQ induced cell apoptosis by regulating the mitochondrial pathway and cell cycle arrest at the G2/M phase via inhibition of the Akt signaling pathway in AGS cells. Furthermore, BQ and OQ significantly increased the levels of reactive oxygen species (ROS) and this effect was blocked by the ROS scavenger NAC in AGS cells. BQ and OQ induced apoptosis by upregulating the protein expression of p38 and JNK and downregulating the levels of ERK and STAT3. Furthermore, expression levels of these proteins were also blocked after NAC treatment. These results demonstrated that BQ and OQ induced apoptosis and cell cycle arrest at the G2/M phase in AGS cells by stimulating ROS generation, which caused subsequent activation of MAPK, Akt and STAT3 signaling pathways. Thus, BQ and OQ may serve as potential therapeutic agents for the treatment of human gastric cancer.

Peroxiredoxin V Reduces ß-Lapachone-induced Apoptosis of Colon Cancer Cells.

BACKGROUND/AIM: Peroxiredoxin (Prx) V has been known as an antioxidant enzyme which scavenges intracellular reactive oxygen species (ROS). Also, Prx V has been shown to mediate cell apoptosis in various cancers. However, the mechanism of Prx V-induced apoptosis in colon cancer cells remains unknown. Thus, in this study we analyzed the effects of Prx V in ß-lapachone-induced apoptosis in SW480 human colon cancer cells. MATERIALS AND METHODS: ß-lapachone-induced apoptosis was analyzed by the MTT assay, western blotting, fluorescence microscopy, Annexin V staining and flow cytometry. RESULTS: Overexpression of Prx V, significantly decreased ß-lapachone-induced cellular apoptosis and Prx V silencing increased ß-lapachone-induced cellular apoptosis via modulating ROS scavenging activity compared to mock SW480 cells. In addition, to further explore the mechanism of Prx V regulated ß-lapachone-induced SW480 cells apoptosis, the Wnt/ß-catenin signaling was studied. The Wnt/ ß-catenin signaling pathway was found to be induced by ß-lapachone. CONCLUSION: Prx V regulates SW480 cell apoptosis via scavenging ROS cellular levels and mediating the Wnt/ß-catenin signaling pathway, which was induced by ß-lapachone.

2-(4-methoxyphenylthio)-5,8-dimethoxy-1,4-naphthoquinone induces apoptosis via ROS-mediated MAPK and STAT3 signaling pathway in human gastric cancer cells.

The 1,4-naphthoquinones and their derivatives have garnered great interest due to their antitumor pharmacological properties in various cancers; however, their clinical application is limited by side effects. In this study, to reduce side effects and improve therapeutic efficacy, a novel 1,4-naphthoquinone derivative-2-(4-methoxyphenylthio)-5,8-dimethoxy-1,4-naphthoquinone (MPTDMNQ) was synthesized. We investigated the effects and underlying mechanisms of MPTDMNQ on cell viability, apoptosis, and reactive oxygen species (ROS) generation in human gastric cancer cells. Our results showed that MPTDMNQ decreased cell viability in nine human gastric cancer cell lines. MPTDMNQ significantly induced apoptosis accompanied by the accumulation of ROS in GC cells. However, pre-treatment with the ROS scavenger N-acetyl-L-cysteine (NAC) attenuated the MPTDMNQ-induced apoptosis. Moreover, MPTDMNQ decreased the phosphorylation levels of extracellular signal-regulated kinase (ERK) and signal transducer and activator of transcription 3 (STAT3); and increased the phosphorylation levels of c-Jun N-terminal kinase (JNK) and p38 kinase. However, phosphorylation was inhibited by NAC and a mitogen-activated protein kinase (MAPK) inhibitor. These findings showed that MPTDMNQ induced AGS cell apoptosis via ROS-mediated MAPK and STAT3 signaling pathways. Thus, MPTDMNQ may be a promising candidate for treating gastric cancer.

The design of 1,4-naphthoquinone derivatives and mechanisms underlying apoptosis induction through ROS-dependent MAPK/Akt/STAT3 pathways in human lung cancer cells.

The natural compound 1,4-naphthoquinone has potent anti-tumor activity. However, the clinical application of 1,4-naphthoquinone and its derivatives has been limited by their side effects. In this study, we attempted to reduce the toxicity of 1,4-naphthoquinone by synthesizing two derivatives: 2,3-dihydro-2,3-epoxy-2-propylsulfonyl-5,8-dimethoxy-1,4-naphthoquinone (EPDMNQ) and 2,3-dihydro-2,3-epoxy-2-nonylsulfonyl-5,8-dimethoxy-1,4-naphthoquinone (ENDMNQ). Then we evaluated the cytotoxicity and molecular mechanisms of these compounds in lung cancer cells. EPDMNQ and ENDMNQ significantly inhibited the viabilities of three lung cancer cell lines and induced A549 cell cycle arrest at the G1 phase. In addition, they induced the apoptosis of A549 lung cancer cells by increasing the phosphorylation of p38 and c-Jun N-terminal kinase (p-JNK), and decreasing the phosphorylation of extracellular signal-related kinase (p-ERK), protein kinase B (Akt), and signal transducer and activator of transcription 3 (STAT3). Furthermore, they increased reactive oxygen species (ROS) levels in A549 cells; however, pretreatment with the ROS inhibitor N-acetyl-l-cysteine significantly inhibited EPDMNQ- and ENDMNQ-mediated apoptosis and reversed apoptotic proteins expression. In conclusion, EPDMNQ and ENDMNQ induced G1 phase cell cycle arrest and apoptosis in A549 cells via the ROS-mediated activation of mitogen activated protein kinase (MAPK), Akt and STAT3 signaling pathways.