Biomedical subjects

Kyung-Sun Kang

Publications and source records attributed to Kyung-Sun Kang.

At least 19 recordsLinked to original sources

PubMed2006

Hepatic gene expression profiling and lipid homeostasis in mice exposed to steatogenic drug, tetracycline.

Tetracycline is one of a group of drugs known to induce microvesicular steatosis. In the present study, we investigated the effects of tetracycline on gene expression in mouse liver, using Applied Biosystems Mouse Genome Survey Microarrays. A single oral dose of 0.1 or 1 g/kg tetracycline was administered to male ICR mice, and liver samples were obtained after 6, 24, or 72 h. Histopathological evaluation showed microvesicular steatosis in the high-dose group at 24 h. In total, 96 genes were identified as tetracycline responsive. Their level of expression differed significantly from controls (two-way analysis of variance; p < 0.05), after adjustment by the Benjamini-Hochberg multiple testing correction, and displayed a twofold or greater induction or repression. The largest groups of gene products affected by tetracycline exposure were those involved in signal transduction, nucleic acid metabolism, developmental processes, and protein metabolism. The expression of genes known to be involved in lipid metabolism was examined, using two-sample Student's t-test for each treatment group versus a corresponding control group. The overall net effects on expression of lipid metabolism genes indicated an increase in cholesterol and triglyceride biosynthesis and a decrease in beta-oxidation of fatty acids. Our data support a proposed mechanism for tetracycline-induced steatogenic hepatotoxicity that involves these processes. Moreover, we demonstrated global changes in hepatic gene expression following tetracycline exposure; many of these genes have the potential to be used as biomarkers of exposure to steatogenic hepatotoxic agents.

Administration, Oral↗

PubMed2006

Comprehensive analysis of differential gene expression profiles on D-galactosamine-induced acute mouse liver injury and regeneration.

Microarray analysis of RNA from d-galactosamine (GalN)-administered mouse livers was performed to establish a global gene expression profile during injury and regeneration stages at two different doses. A single dose of GalN at 266 or 26.6 mg/kg body weight was given intraperitoneally, and the liver samples were obtained after 6, 24, and 72 h. Histopathologic studies enabled the classification of the D-galactosamine effect into injury (6, 24 h) and regeneration (72 h) stages. By using the Applied Biosystems mouse genome survey microarray, a total of 7267 out of 33,315 (21.8%) genes were found to be statistically reliable at p<0.05 by two-way ANOVA, and 1469 (4.4%) probes at false discovery rate <5% by significance analysis of microarray. Among the statistically reliable clones by both analytical methods, 389 genes were differentially expressed when compared with non-treated control, with more than a 1.625-fold difference (which equals 0.7 in log(2) scale) at one or more GalN treatment conditions and with less than 1.625-fold difference at all three vehicle-treated conditions. Three hundred thirty six genes and 13 genes were identified as injury- and regeneration-specific genes, respectively, showing that most of the transcriptomic changes were seen during the injury stage. Furthermore, multiple genes involved in protein synthesis and degradation, mRNA processing and binding, and cell cycle regulation showed variable transcript levels upon acute GalN administration.

Acute Disease↗

PubMed2006

Potent inhibition of Lewis lung cancer growth by heyneanol A from the roots of Vitis amurensis through apoptotic and anti-angiogenic activities.

Vitis amurensis Rupr. (Vitaceae) has long been used in Chinese/Oriental herbal medicine for the treatment of cancer, but its active compounds and mechanisms of action have not been well studied. To this end, we isolated from its root heyneanol A (HA), which is a tetramer of resveratrol (RES), and established the in vivo antitumor activity of HA using the mouse Lewis lung carcinoma (LLC) model. We administered HA and RES by daily intraperitonial injection to C57BL/6 mice that were subcutaneously inoculated with LLC cells. HA dose-dependently decreased tumor growth without any adverse effect on body weight and seemed more potent than RES. The tumor inhibitory effects were accompanied by a marked increase in tumor cell apoptosis detected by cleaved caspase-3 and TUNEL assays and decreased tumor cell proliferation index and tumor microvessel density, supporting the involvement of apoptotic and anti-angiogenic activities in the anticancer effects. We next investigated the cellular and molecular processes that mediate the apoptosis and anti-angiogenesis effects using cell culture models. Mechanistically, treatment of LLC cells in vitro with HA or RES significantly increased apoptotic cells. Both HA- and RES-induced cleavage of caspase-9 and caspase-3 and PARP were completely blocked by a pan caspase inhibitor, Z-VAD-FMK. In addition, HA and RES suppressed the basic fibroblast growth factor (bFGF)-induced proliferation and capillary differentiation of human umbilical vein endothelial cells, and inhibited the binding of bFGF to its receptor in a test tube assay and the bFGF-induced vascularization of Matrigel plugs in vivo. Remarkably, HA was fairly stable in cell culture medium and did not undergo intracellular conversion to RES. Therefore, HA is an active anticancer compound that induces caspase-mediated cancer cell apoptosis and inhibits angiogenesis rivaling the potency of RES and merits further evaluation for cancer chemoprevention.

Angiogenesis Inhibitors↗

PubMed2006

Successful stem cell therapy using umbilical cord blood-derived multipotent stem cells for Buerger's disease and ischemic limb disease animal model.

Buerger's disease, also known as thromboangiitis obliterans, is a nonatherosclerotic, inflammatory, vasoocclusive disease. It is characterized pathologically as a panangiitis of medium and small blood vessels, including both arteries and adjacent veins, especially the distal extremities (the feet and the hands). There is no curative medication or surgery for this disease. In the present study, we transplanted human leukocyte antigen-matched human umbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) into four men with Buerger's disease who had already received medical treatment and surgical therapies. After the stem cell transplantation, ischemic rest pain suddenly disappeared from their affected extremities. The necrotic skin lesions were healed within 4 weeks. In the follow-up angiography, digital capillaries were increased in number and size. In addition, vascular resistance in the affected extremities, compared with the preoperative examination, was markedly decreased due to improvement of the peripheral circulation. Because an animal model of Buerger's disease is absent and also to understand human results, we transplanted human UCB-derived MSCs to athymic nude mice with hind limb ischemia by femoral artery ligation. Up to 60% of the hind limbs were salvaged in the femoral artery-ligated animals. By in situ hybridization, the human UCB-derived MSCs were detected in the arterial walls of the ischemic hind limb in the treated group. Therefore, it is suggested that human UCB-derived MSC transplantation may be a new and useful therapeutic armament for Buerger's disease and similar ischemic diseases.

Adult↗

PubMed2006

MAPK regulation and caspase activation are required in DMNQ S-52 induced apoptosis in Lewis lung carcinoma cells.

6-(1-Hydroxyimino-4-methylpentyl)5,8-dimethyoxy 1,4-naphthoquinone S-52 (DMNQ S-52) was reported to have cytotoxic activity against L1210 leukemia cells. In the present study, we investigated the apoptotic mechanism of DMNQ S-52 in vitro and in vivo in murine solid cancer cells. DMNQ S-52 exerted cytotoxicity against Lewis lung carcinoma (LLC) cells (IC50=12.3 microM). DMNQ S-52 increased Annexin V positive cell population in a concentration-dependent manner. DMNQ S-52 also induced apoptosis through caspase-mediated pathway, including activation of caspase-3, cleavage of Poly(ADP-ribose) polymerase (PARP) and decreased expression of Bcl-2 in LLC cells in a time and concentration-dependent fashion. DMNQ S-52 activated the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 as well as abrogated the expression of extracellular signal-regulated kinase (ERK) in a time-dependent manner at 10 microM. Similarly, cell proliferation inhibition by DMNQ S-52 was masked by caspase inhibitor Z-Asp-Glu-Val-Asp-fluoromethylketone (Z-VAD-FMK), JNK inhibitor SP600125 and p38 inhibitor SB203580, but not by MEK inhibitor U0126. Furthermore, i.p. administration of DMNQ S-52 at 5 mg/kg resulted in a potent inhibition of the growth of LLC cells implanted on the right flank of C57BL/6 mice compared to untreated control. Immunohistochemical analysis revealed the decreased tumor cell proliferation and increased tumor cell apoptosis in DMNQ S-52 treated tumor sections using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) and proliferation cell nuclear antigen (PCNA). Taken together, these findings demonstrate that DMNQ S-52 may exhibit anti-tumor activity by inducing apoptosis via caspases and mitogen activated protein (MAP) kinase-dependent pathways.

Animals↗

PubMed2006

Reversal of the TPA-induced inhibition of gap junctional intercellular communication by Chaga mushroom (Inonotus obliquus) extracts: effects on MAP kinases.

Chaga mushroom (Inonotus obliquus) has continued to receive attention as a folk medicine with indications for the treatment of cancers and digestive diseases. The anticarcinogenic effect of Chaga mushroom extract was investigated using a model system of gap junctional intercellular communication (GJIC) in WB-F344 normal rat liver epithelial cells. The cells were pre-incubated with Chaga mushroom extracts (5, 10, 20 microg/ml) for 24 h and this was followed by co-treatment with Chaga mushroom extracts and TPA (12-O-tetradecanoylphorbol-13-acetate, 10 ng/ml) for 1 h. The inhibition of GJIC by TPA (12-O-tetradecanoylphorbol-13-acetate), promoter of cancer, was prevented with treatment of Chaga mushroom extracts. Similarly, the increased phosphorylated ERK1/2 and p38 protein kinases were markedly reduced in Chaga mushroom extracts-treated cells. There was no change in the JNK kinase protein level, suggesting that Chaga mushroom extracts could only block the activation of ERK1/2 and p38 MAP kinase. The Chaga mushroom extracts further prevented the inhibition of GJIC through the blocking of Cx43 phosphorylation. Indeed cell-to-cell communication through gap junctional channels is a critical factor in the life and death balance of cells because GJIC has an important function in maintaining tissue homeostasis through the regulation of cell growth, differentiation, apoptosis and adaptive functions of differentiated cells. Thus Chaga mushroom may act as a natural anticancer product by preventing the inhibition of GJIC through the inactivation of ERK1/2 and p38 MAP kinase.

Agaricales↗

PubMed2006

Low molecular proanthocyanidin dietary biofactor Oligonol: Its modulation of oxidative stress, bioefficacy, neuroprotection, food application and chemoprevention potentials.

Interdisciplinary research endeavors are directed at understanding the molecular mechanisms of neurodegenerative and chronic diseases that affect human lifestyle. Hence the potential for developing medicinal herb-derived and food plant-derived prophylactic agents directed at neurological, metabolic, cardiovascular and psychiatric disorders abounds. Oligonol is a novel technology product emanating from the oligomerization of polyphenols, typically proanthocyanidin from a variety of fruits (grapes, apples, persimmons etc.) that has optimized bioavailability. It is an optimized phenolic product containing catechin-type monomers and oligomeric proanthocyanidins, the easily absorbed forms. Typically the constituents of Oligonol are 15-20% monomers, 8-12% dimers and 5-10% trimers. Supplementation of mice with Oligonol prior to the administration of ferric-nitrilotriacetic complex (a Fenton chemistry model) significantly reduced the extent of lipid peroxidation in the kidney, brain and liver. Oligonol triggers apoptosis in the MCF-7 and MDA-MB-231 breast cancer cells through modulation of the pro-apoptotic Bcl-2 family of proteins and the MEK/ERK signaling pathway, an observation suggesting its important chemopreventive effects. The senescence-accelerated strain of mice (SAM) are models of senescence acceleration and geriatric disorders which exhibit learning and memory deficits and enhanced production or defective control of oxidative stress leading.

Animals↗

PubMed2006

Alteration of the glutamate and GABA transporters in the hippocampus of the Niemann-Pick disease, type C mouse using proteomic analysis.

Niemann-Pick disease type C (NPC) is a fatal autosomal recessive cholesterol disorder characterized by severe progressive neurodegeneration. To unveil the mechanism of neurodegeneration, proteomic and morphological approaches were applied to the hippocampus in NPC -/- mouse. Two-DE was utilized to resolve the hippocampal protein expression profiles of 4- and 8-week-old NPC +/+ and -/- mice. Differentially expressed protein spots were identified by MALDI-TOF MS and database searching. At 4 weeks of age, there was no significant difference in protein profiles between NPC +/+ and -/- mice. However, at the age of 8 weeks, NPC +/+ and -/- mice showed marked difference in protein expressions. Among these, glutamate receptor 2 precursor was identified. The immunohistochemical study on neurotransporters showed that glial GABA transporter (GAT-3) increased in both 4- and 8-week-old NPC -/- mouse and glutamic acid decarboxylase (GAD-6) increased in 8-week-old NPC -/- mouse. Glial glutamate transporter, excitatory amino acids carrier-1 (EAAC1), decreased in 8-week-old NPC -/- mouse. In conclusion, our data may provide insight into the understanding of the basic mechanism through perturbation of protein networks and neurotransporter systems in a single gene knockout model of NPC disease.

Amino Acid Transport System X-AG↗

PubMed2006

In vivo bioluminescence imaging of cord blood derived mesenchymal stem cell transplantation into rat myocardium.

OBJECTIVE: The conventional method for the analysis of myocardial cell transplantation depends on postmortem histology. Here, we have sought to demonstrate the feasibility of a longitudinal monitoring of transplanted cell survival in living animals, accomplished with optical imaging techniques and pharmacological interventions. METHODS: Human cord blood (50 ml) was donated with parental consent. After getting cord blood derived mesenchymal stem cells (CBMSCs), cells were transfected (MOI = 100) overnight with adenovirus encoding firefly luciferase gene (Ad-CMV-Fluc). Our experimental Sprague-Dawley rats (n = 12) were given intramyocardial injections containing 1 x 10(6) CBMSCs, which had been made to express the firefly luciferase (Fluc) reporter gene. Optical bioluminescence imaging was then conducted using a cooled charged-coupled device (CCD) camera (Xenogen), beginning on the day after the transplantation (day 1). Groups of mice were intraperitoneally injected with cyclosporine (5 mg/kg) or tacrolimus (1 mg/kg), in an attempt to determine the degree to which cell survival had been prolonged, and these values were then compared with the cell survival values of the negative control group. The presence of transplanted CBMSCs on in vivo images confirmed by in situ hybridization for human specific Alu in the myocardium. RESULTS: Cardiac bioluminescence signals were determined to be present for 6 days after transplantation: day 1 (97000 +/- 9100 x 10(5) p/s/cm2/sr), day 3 (9600 +/- 1110 p/s/cm2/sr), and day 5 (3200 +/- 550 p/s/cm2/sr). The six mice that received either cyclosporine or tacrolimus displayed cardiac bioluminescence signals for a period of 8 days after transplantation. We observed significant differences between the treated group and the non-treated group, beginning on day 3 (tacrolimus; 26500 +/- 4340 p/s/cm2/sr, cyclosporine; 27200 +/- 3340 p/s/cm2/sr, non-treated; 9630 +/- 1180 p/s/cm2/sr, p < 0.01), and persisting until day 7 (tacrolimus; 12500 +/- 2946 p/s/cm2/sr, cyclosporine; 7310 +/- 1258 p/s/cm2/sr, non-treated; 2460 +/- 160 p/s/cm2/sr, p < 0.01). The human-derived CBMSCs were detected in the myocardium 3 days after transplantation by in situ hybridization. CONCLUSIONS: The locations, magnitude, and survival duration of the CBMSCs were noninvasively monitored with a bioluminescence optical imaging system. We determined that optical molecular imaging expedites the fast throughput screening of pharmaceutical agents, allowing for the noninvasive tracking of cell survival within animals. In rat cardiac CBMSC transplant models, transient immunosuppressive treatment with tacrolimus or cyclosporine was shown to improve donor cell survival.

Animals↗

PubMed2006

Effect of exercise on hepatic gene expression in an obese mouse model using cDNA microarrays.

To understand the molecular mechanisms involved in the effect of exercise training, we examined hepatic transcriptional profiles using cDNA microarrays in exercise-trained and untrained mice with diet-induced obesity. C57BL/6J male mice (n = 10/group) were fed with a normal diet, high-fat diet (HFD), or HFD with exercise training for 12 weeks. The expression level of approximately 10,000 transcripts in liver tissues from each group was assessed using cDNA microarray analysis. Exercise training improved lipid profiles and hepatic steatosis and decreased body fat mass induced by the HFD. Seventy-three genes were differentially expressed in the HFD- and/or HFD with exercise training-treated groups, compared with the normal diet- and HFD-fed groups, respectively. Interestingly, the expression profiles involved in metabolism, such as elongation of very long chain fatty acids-like 2, lipin, and malic enzyme, were changed by exercise training. In addition, expression of genes altered by exercise training related to defense and stress response, including metallothionein 1 and 2 and heat shock protein, showed interesting findings. Our study showed beneficial effects of exercise training in preventing the development of obesity and metabolic disorders in mice with diet-induced obesity.

Analysis of Variance↗

PubMed2006

Critical role of the c-JunNH2-terminal kinase and p38 mitogen-activated protein kinase pathways on sodium butyrate-induced apoptosis in DU145 human prostate cancer cells.

Sodium butyrate (NaBu) is known to exhibit anti-cancer effects via the differentiation and apoptosis of various carcinoma cells. However, the mechanism by which NaBu induces apoptosis and the involvement of protein kinases during apoptosis is not completely understood. To investigate the underlying pathways, we performed cell culture experiments in androgen-independent human prostate cancer (DU145 cells) focusing on various protein kinases. NaBu causes concentration-dependent cell detachment and growth inhibition. Exposure of DU145 cells to NaBu for 24 h caused a strong apoptotic effect with 26% nuclear fragmentation and condensation. In addition, NaBu induced caspase-3 and poly-ADP ribose polymerase cleavage and up-regulation of bax, suggesting that mitochondrial damage is involved in NaBu-induced caspase-dependent apoptosis. Interestingly, NaBu stimulated p38 mitogen-activated protein kinase (MAPK) and c-Jun NH2-terminal kinase (JNK) activation, but not extracellular signal-regulated kinase 1/2 activation during apoptosis. Furthermore, NaBu up-regulated total protein levels and phospho forms of MAPK kinase 3 (MKK3) and MAPK kinase 4 (MKK4) as the upstream kinases of p38 MAPK and JNK independently of oxidative stress. Taken together, it is suggested that NaBu can be a promising chemopreventive agent for prostate cancer and the p38 MAPK and JNK pathways have critical roles in NaBu-induced apoptosis in DU145 cells.

Apoptosis↗

PubMed2006

Expression of MAP kinases and connexins in the differentiation of rat mammary epithelial cells.

Gap junctional intercellular communication (GJIC) is involved in the regulation of many cellular processes. MAP kinases are known to affect GJIC and phosphorylation of connexin (Cx). MAP kinases can also be a regulator of cell proliferation and growth. This study was undertaken to show the relevance between expression patterns of Cxs and MAP kinases in rat mammary epithelial cells (RMECs). In order to characterize the RMECs, they were stained with Peanut lectin, which indicates most alveolar epithelial cells, and Thy-1.1 was used as a marker of luminal epithelial cells or myoepithelial cells, respectively. We studied the expression patterns of major gap junction proteins, Cx26, 32, and 43 in RMECs. Western blot analysis demonstrated that Cx26 gradually decreased from day 2, while Cx32 was expressed constantly from day 1 to 14. Cx43 dramatically increased on day 5 and decreased thereafter. The expression patterns and phosphorylation of ERK1/2 and JNK were similar to Cx43, but expression of p38 was like that of Cx32. These results showed that the MAP kinases that comprise ERK1/2, p38, and JNK were involved in regulation of Cxs. Our data suggests that GJIC plays an important role during rat mammary differentiation and that MAP kinases may be closely related functionally to regulate the gap junction.

Animals↗

PubMed2006

In vitro neuronal and osteogenic differentiation of mesenchymal stem cells from human umbilical cord blood.

Mesenchymal stem cells (MSCs) have the capabilities for self-renewal and differentiation into cells with the phenotypes of bone, cartilage, neurons and fat cells. These features of MSCs have attracted the attention of investigators for using MSCs for cell-based therapies to treat several human diseases. Because bone marrow-derived cells, which are a main source of MSCs, are not always acceptable due to a significant drop in their cell number and proliferative/differentiation capacity with age, human umbilical cord blood (UCB) cells are good substitutes for BMCs due to the immaturity of newborn cells. Although the isolation of hematopoietic stem cells from UCB has been well established, the isolation and characterization of MSCs from UCB still need to be established and evaluated. In this study, we isolated and characterized MSCs. UCB-derived mononuclear cells, which gave rise to adherent cells, exhibited either an osteoclast or a mesenchymal-like phenotype. The attached cells with mesenchymal phenotypes displayed fibroblast-like morphologies, and they expressed mesenchymal-related antigens (SH2 and vimentin) and periodic acid Schiff activity. Also, UCB-derived MSCs were able to transdifferentiate into bone and 2 types of neuronal cells, in vitro. Therefore, it is suggested that the MSCs from UCB might be a good alternative to bone marrow cells for transplantation or cell therapy.

Acid Phosphatase↗

PubMed2005

Chemopreventive properties of the ethanol extract of chinese licorice (Glycyrrhiza uralensis) root: induction of apoptosis and G1 cell cycle arrest in MCF-7 human breast cancer cells.

Much of the interest on the chemopreventive properties of licorice has been focused on the plant genius Glycyrrhiza glabra. In this study the ethanol extract of Chinese licorice root, Glycyrrhiza uralensis (G. uralensis) was investigated for its estrogenic effect and the ability to inhibit cell proliferation in the MCF-7 human breast cancer cell line. The extract of the root of G. uralensis was fractionated in EtOH:H(2)O (80:20) (80% ethanol). The extract exhibited estrogenic effects similar to 17beta- estradiol (E2) and induced apoptosis at the same dose level (100 microg/ml) in MCF-7 breast cancer cells, results were associated with up-regulation of tumor suppressor gene p53 and pro-apoptotic protein Bax. G. uralensis extract caused the up-regulation of p21(waf1/cip1) and down-regulation of cdk 2 and cyclin E and most significantly, induced G1 cell cycle arrest. This is the first study to show that the ethanolic extract of the root of G. uralensis has an estrogen-like activity and anti-cancer effects against MCF-7 human breast cancer cells. Whilst the use of phytoestrogens to protect against hormone-dependent cancers or as a 'natural' alternative to hormone replacement therapy remains controversial, the data in this paper support the suggestion that extracts of root of the Chinese licorice G. uralensis might be of importance in this debate.

Anticarcinogenic Agents↗

PubMed2005

Effects of the histone deacetylases inhibitors sodium butyrate and trichostatin A on the inhibition of gap junctional intercellular communication by H2O2- and 12-O-tetradecanoylphorbol-13-acetate in rat liver epithelial cells.

The histone deacetylase (HDAC) inhibitors, trichostatin A (TSA) and sodium butyrate (NaBu) are considered as potent therapeutic agents for cancer treatment presenting therapeutic benefits with less risk of side effects. The microbial metabolite, TSA is a potent reversible and highly specific inhibitor of mammalian histone deacetylases. NaBu causes hyperacetylation of core histones with effects similar to TSA but it is not a specific inhibitor of HDACs. The gap junction is a channel in the plasma membrane of most cell types which allows direct communication (gap junctional intercellular communication; GJIC) of small molecules and ions. Modulation of GJIC is a known cellular event associated with tumor promotion. The effects of NaBu and TSA on the H(2)O(2)- and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced GJIC inhibition of WB cells and the mechanisms involved in the process were assessed. TSA and NaBu exerted differential preventive effects on the H(2)O(2) and TPA-induced inhibition of GJIC as well as hyperphosphorylation of connexin43 (Cx43) in WB-F344 rat liver epithelial cells (WB cells). NaBu prevented the TPA-induced GJIC inhibition via ERK1/2 inactivation whilst TSA restored the H(2)O(2)-induced GJIC inhibition and Cx43 hyperphosphorylation by preventing p38 MAP kinase. The inhibition of tyrosine phosphorylation and down-regulation of src protein observed may also contribute to Connexin 43 dephosphorylation and GJIC restoration by TSA and NaBu partly through depletion of src protein pool. Thus, TSA and NaBu exert differential effects on chemically induced GJIC inhibition via modulation of MAP kinases and partly, tyrosine kinases.

Animals↗

PubMed2005

Neogenin expression may be inversely correlated to the tumorigenicity of human breast cancer.

BACKGROUND: Neogenin is expressed in cap cells that have been suggested to be mammary stem or precursor cells. Neogenin is known to play an important role in mammary morphogenesis; however its relationship to tumorigenesis remains to be elucidated. METHODS: To compare the expression levels of neogenin in cells with different tumorigenicity, the expression levels in M13SV1, M13SV1R2 and M13SV1R2N1 cells, which are immortalized derivatives of type I human breast epithelial cells, were evaluated. Then we measured the expression level of neogenin in paired normal and cancer tissues from eight breast cancer patients. Tissue array analysis was performed for 54 human breast tissue samples with different histology, and the results were divided into four categories (none, weak, moderate, strong) by a single well-trained blinded pathologist and statistically analyzed. RESULTS: The nontumorigenic M13SV1 cells and normal tissues showed stronger expression of neogenin than the M13SV1R2N1 cells and the paired cancer tissues. In the tissue array, all (8/8) of the normal breast tissues showed strong neogenin expression, while 93.5% (43/46) of breast cancer tissues had either no expression or only moderate levels of neogenin expression. There was a significant difference, in the expression level of neogenin, in comparisons between normal and infiltrating ductal carcinoma (p < 0.001). CONCLUSION: Neogenin may play a role in mammary carcinogenesis as well as morphogenesis, and the expression may be inversely correlated with mammary carcinogenicity. The value of neogenin as a potential prognostic factor needs further evaluation.

Biomarkers, Tumor↗

PubMed2005

Chinese cabbage extracts and sulforaphane can protect H2O2-induced inhibition of gap junctional intercellular communication through the inactivation of ERK1/2 and p38 MAP kinases.

The cruciferous vegetables such as Chinese cabbages and broccoli are known to have anticancer phytochemicals, and the consumption of cruciferous vegetables has been proposed to protect against various cancers. The anticarcinogenic properties of some Chinese cabbage extracts and sulforaphane glucosinolate (SFN) were assessed by examining their ability to prevent the inhibition of gap junctional intercellular communication (GJIC) induced by hydrogen peroxide (H2O2) in WB-F344 normal rat liver epithelial cells. The cells were preincubated with Chinese cabbage extracts and SFN for 24 h followed by cotreatment with cells and H2O2 (750 microM) for 1 h. Chinese cabbage extracts and SFN prevented the inhibition of GJIC and phosphorylation of gap junction protein connexin43 (Cx43) by H2O2 treatment. Chinese cabbage extracts and SFN were able to prevent the inhibition of GJIC through the blocking of Cx43 phosphorylaton and inactivation of ERK 1/2 and p38 MAP kinase. The results suggest that cruciferous vegetables and their components, SFN, may exert the anticancer effect by targeting the GJIC as a functional dietary chemopreventive agent.

Bidens↗

PubMed2005

NPC1 gene deficiency leads to lack of neural stem cell self-renewal and abnormal differentiation through activation of p38 mitogen-activated protein kinase signaling.

Neural stem cells (NSCs) are capable of giving rise to neurons, glia, and astrocytes. Although self-renewal and differentiation in NSCs are regulated by many genes, such as Notch and Numb, little is known about the role of defective genes on the self-renewal and differentiation of NSCs from developing brain. The Niemann-Pick type C1 (NPC1) disease is a neurodegenerative disease caused by a mutation of the NPC1 gene that affects the function of the NPC1 protein. The ability of NSC self-renewal and differentiation was investigated using a model of NPC1 disease. The NPC1 disorder significantly affected the self-renewal ability of NSCs, as well as the differentiation. NSCs from NPC1-/- mice showed impaired self-renewal ability compared with the NPC1+/+ mice. These alterations were accompanied by the enhanced activity of p38 mitogen-activated protein kinases (MAPKs). Further, the specific p38 MAPK inhibitor SB202190 improved the self-renewal ability of NSCs from NPC-/- mice. This indicated that the NPC1 deficiency can lead to lack of self-renewal and altered differentiation of NSCs mediated by the activation of p38 MAPK, impairing the generation of neurospheres from NPC1-/- Thus, the NPC1 gene may play a crucial role in NSC self-renewal associated with p38 MAPK.

Animals↗