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1.  Role of 15-hydroxyprostaglandin dehydrogenase down-regulation on the prognosis of hepatocellular carcinoma 
The role of prostaglandin E2 (PGE2) in the modulation of cell growth is well established in colorectal cancer. The aim of this study was to elucidate the significance of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) down-regulation on the prognosis of hepatocellular carcinoma (HCC) patients.
The expression of 15-PGDH in HCC cell lines and resected HCC tissues was investigated, and the correlation between 15-PGDH expression and HCC cell-line proliferation and patient survival was explored.
The interleukin-1-β-induced suppression of 15-PGDH did not change the proliferation of PLC and Huh-7 cells in the MTS [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The induction of 15-PGDH by transfection in HepG2 cells without baseline 15-PGDH expression was suppressed at day 2 of proliferation compared with empty-vector transfection, but there was no difference at day 3. Among the 153 patients who received curative HCC resection between 2003 and 2004 at our institution, 15-PGDH expression was observed in resected HCC tissues in 56 (36.6%), but the 5-year survival rate did not differ from that of the remaining 97 non-15-PGDH-expressing patients (57.1% vs 59.8%; P=0.93). Among 50 patients who exhibited baseline 15-PGDH expression in adjacent nontumor liver tissues, 28 (56%) exhibited a reduction in 15-PGDH expression score in HCC tissues, and there was a trend toward fewer long-term survivors compared with the remaining 22 with the same or increment in their 15-PGDH expression score in HCC tissues.
The prognostic significance of 15-PGDH down-regulation in HCC was not established in this study. However, maintenance of 15-PGDH expression could be a potential therapeutic target for a subgroup of HCC patients with baseline 15-PGDH expression in adjacent nontumor liver tissue.
PMCID: PMC3992327  PMID: 24757656
Hepatocellular carcinoma; 15-hydroxyprostaglandin dehydrogenase; Transfection; Immunohistochemistry; Survival analysis
3.  Pseudo-Spontaneous Nystagmus in Lateral Semicircular Canal Benign Paroxysmal Positional Vertigo 
Spontaneous nystagmus, which has been considered a typical sign of acute vestibulopathy, has recently been reported in benign paroxysmal positional vertigo involving the lateral semicircular canals (LC-BPPV) without unilateral vestibulopathy (pseudo-spontaneous nystagmus, PSN), but research about its clinical application is still limited. Here we investigate the frequency and characteristics of PSN in LC-BPPV patients, and estimate its prognostic value.
For 95 patients with LC-BPPV, we examined nystagmus in the sitting position in the clinic with video goggles. Patients were categorized as PSN or non-PSN, according to presence of horizontal nystagmus in the sitting position at diagnosis. The duration of vertiginous symptoms before diagnosis and the duration of treatment were compared between the two groups. The results of video-nystagmography test were reviewed when available.
PSN was examined in 16 (16.8%) patients, all of whose symptoms disappeared immediately after successful repositioning therapy. While the duration of symptoms did not differ statistically between groups (P=0.481), the duration of treatment in the PSN group was significantly longer than in the non-PSN group (P<0.001).
We conclude that the presence of spontaneous nystagmus in the sitting position does not preclude a diagnosis of LC-BPPV without unilateral vestibulopathy. PSN was related to a poor outcome of LC-BPPV in this study.
PMCID: PMC3506770  PMID: 23205224
Benign paroxysmal positional vertigo; Pathologic nystagmus; Semicircular canals
4.  Inhibition of Hypoxia Inducible Factor Alpha and Astrocyte-Elevated Gene-1 Mediates Cryptotanshinone Exerted Antitumor Activity in Hypoxic PC-3 Cells 
Although cryptotanshinone (CT) was known to exert antitumor activity in several cancers, its molecular mechanism under hypoxia still remains unclear. Here, the roles of AEG-1 and HIF-1α in CT-induced antitumor activity were investigated in hypoxic PC-3 cells. CT exerted cytotoxicity against prostate cancer cells and suppressed HIF-1α accumulation and AEG-1 expression in hypoxic PC-3 cells. Also, AEG-1 was overexpressed in prostate cancer cells. Interestingly, HIF-1α siRNA transfection enhanced the cleavages of caspase-9,3, and PAPR and decreased expression of Bcl-2 and AEG1 induced by CT in hypoxic PC-3 cells. Of note, DMOG enhanced the stability of AEG-1 and HIF-1α during hypoxia. Additionally, CT significantly reduced cellular level of VEGF in PC-3 cells and disturbed tube formation of HUVECs. Consistently, ChIP assay revealed that CT inhibited the binding of HIF-1α to VEGF promoter. Furthermore, CT at 10 mg/kg suppressed the growth of PC-3 cells in BALB/c athymic nude mice by 46.4% compared to untreated control. Consistently, immunohistochemistry revealed decreased expression of Ki-67, CD34, VEGF, carbonic anhydrase IX, and AEG-1 indices in CT-treated group compared to untreated control. Overall, our findings suggest that CT exerts antitumor activity via inhibition of HIF-1α, AEG1, and VEGF as a potent chemotherapeutic agent.
PMCID: PMC3519236  PMID: 23243443
5.  Korean Clinical Practice Guidelines: Otitis Media in Children 
Journal of Korean Medical Science  2012;27(8):835-848.
Acute otitis media (AOM) and otitis media with effusion (OME) are common infections in children, and their diagnosis and treatment have significant impacts on the health of children and the costs of providing national medical care. In 2009, the Korean Otologic Society organized a committee composed of experts in the field of otolaryngology, pediatrics, and family medicine to develop Korean clinical practice guidelines (CPG) for otitis media in children with the goal of meeting regional medical and social needs in Korea. For this purpose, the committee adapted existing guidelines. A comprehensive literature review was carried out primarily from 2004 to 2009 using medical search engines including data from Korea. A draft was written after a national questionnaire survey and several public audits, and it was editorially supervised by senior advisors before publication of the final report. These evidence-based guidelines for the management of otitis media in children provide recommendations to primary practitioners for the diagnosis and treatment of children younger than 15 yr old with uncomplicated AOM and OME. The guidelines include recommendations regarding diagnosis, treatment options, prevention and parent education, medical records, referral, and complementary/alternative medicine for treating pediatric otitis media.
PMCID: PMC3410229  PMID: 22876048
Otitis Media; Acute Disease; Otitis Media with Effusion; Child; Diagnosis; Treatment; Guideline
6.  1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG) reduces renal crystallization and oxidative stress in a hyperoxaluric rat model 
Kidney international  2010;79(5):538-545.
Adhesion of calcium oxalate (CaOx) crystals to kidney cells may be a key event in the pathogenesis of kidney stones associated with marked hyperoxaluria. Previously, we found that 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG), isolated from a traditional medicinal herb, reduced CaOx crystal adhesion to renal epithelial cells by acting on the cells as well as the crystal surface. Here we used the ethylene glycol (EG) - mediated hyperoxaluric rat model and found evidence of oxidant stress as indicated by decreases in the activities of the renal antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase, with increased kidney cell apoptosis and serum malondialdehyde levels, all evident by 21 days of EG treatment. These effects of hyperoxaluria were reversed by concurrent PGG treatment along with decreased urinary oxalate levels and CaOx supersaturation. Renal epithelial cell expression of the crystal binding molecule hyaluronan increased diffusely within 7 days of EG initiation, suggesting it is not a result of but precedes crystal deposition. Renal cell osteopontin (OPN) was also up regulated in EG-treated animals, and PGG significantly attenuated over expression of both OPN and hyaluronan. Thus, our findings demonstrate that PGG reduces renal crystallization and oxidative renal cell injury, and may be a candidate chemo preventative agent for nephrolithiasis.
PMCID: PMC4019041  PMID: 21085110
7.  Photothermal cancer therapy using graphitic carbon–coated magnetic particles prepared by one-pot synthesis 
We describe here a simple synthetic strategy for the fabrication of carbon-coated Fe3O4 (Fe3O4@C) particles using a single-component precursor, iron (III) diethylenetriaminepentaacetic acid complex. Physicochemical analyses revealed that the core of the synthesized particles consists of ferromagnetic Fe3O4 material ranging several hundred nanometers, embedded in nitrogen-doped graphitic carbon with a thickness of ~120 nm. Because of their photothermal activity (absorption of near-infrared [NIR] light), the Fe3O4@C particles have been investigated for photothermal therapeutic applications. An example of one such application would be the use of Fe3O4@C particles in human adenocarcinoma A549 cells by means of NIR-triggered cell death. In this system, the Fe3O4@C can rapidly generate heat, causing >98% cell death within 10 minutes under 808 nm NIR laser irradiation (2.3 W cm−2). These Fe3O4@C particles provided a superior photothermal therapeutic effect by intratumoral delivery and NIR irradiation of tumor xenografts. These results demonstrate that one-pot synthesis of carbon-coated magnetic particles could provide promising materials for future clinical applications and encourage further investigation of this simple method.
PMCID: PMC4284004  PMID: 25565819
graphitic carbon–encapsulated magnetic nanoparticles; iron oxide; one-pot synthesis; photothermal cancer therapy
8.  Aesculetin suppresses proliferation of human colon cancer cells by directly targeting β-catenin 
Cancer prevention research (Philadelphia, Pa.)  2013;6(12):10.1158/1940-6207.CAPR-13-0241.
The Wnt pathway is a promising therapeutic and preventive target in various human cancers. The transcriptional complex of β-catenin/Tcf, a key mediator of canonical Wnt signaling, has been implicated in human colon cancer development. Current treatment of colon cancer depends on traditional cytotoxic agents with limited effects. Therefore, the identification of natural compounds that can disrupt the β–catenin/TcF complex to suppress cancer cell growth with fewer adverse side effects is needed. To identify compounds that inhibit the association between β-catenin and Tcf, we used computer docking to screen a natural compound library. Aesculetin, also known as 6,7-dihydroxycoumarin, is a derivative of coumarin and was identified as a potential small molecule inhibitor of the Wnt/β-catenin pathway. We then evaluated the effect of aesculetin on the growth of various human colon cancer cell lines and its effect on Wnt/β-catenin signaling in cells and in an embryonic model. Aesculetin disrupted the formation of the β-catenin/Tcf complex through direct binding with the Lys312, Gly307, Lys345 and Asn387 residues of β-catenin in colon cancer cells. Additionally, aesculetin effectively decreased viability and inhibited anchorage-independent growth of colon cancer cells. Aesculetin potently antagonized the cellular effects of β-catenin-dependent activity and in vivo treatment with aesculetin suppressed tumor growth in a colon cancer xenograft mouse model. Our data indicate that the interaction between aesculetin and β-catenin inhibits the formation of the β-catenin/Tcf complex, which could contribute to aesculetin’s positive therapeutic and preventive effects against colon carcinogenesis.
PMCID: PMC3885338  PMID: 24104353
aesculetin; human colon cancer; Wnt; β-catenin; Tcf
9.  Essential oil of Pinus koraiensis inhibits cell proliferation and migration via inhibition of p21-activated kinase 1 pathway in HCT116 colorectal cancer cells 
The essential oil of Pinus koraiensis (EOPK) is biologically active compound obtained from the leaves of P. koraiensis. The goal of this study was to investigate the anti-cancer mechanism of EOPK in HCT116 colorectal cancer cells.
HCT116 cell proliferation was assessed by conducting crystal violet and BrdU assays. To assess the effects of EOPK on cell migration, we performed a wound-healing assay. Further, the contribution of PAK1 to EOPK-induced AKT and extracellular signal-regulated kinase (ERK) suppression was assessed by siRNA-mediated PAK1 knockdown. Changes to the expression and phosphorylation of PAK1 and its effectors were determined by western blotting, and changes to the actin cytoskeleton were determined by performing an immunofluorescence assay.
EOPK significantly decreased HCT116 cell proliferation and migration, and induced G1 arrest without affecting normal cells. Additionally, EOPK suppressed the expression of PAK1, and decreased ERK and AKT phosphorylation in HCT116 cells. Finally, EOPK suppressed β-catenin, cyclin D1, and CDK4/6 expression.
Our studies indicate that EOPK significantly reduced proliferation and migration of colorectal cancer cells. Furthermore, EOPK suppressed PAK1 expression in a dose-dependent manner, and this suppression of PAK1 led to inhibition of ERK, AKT, and β-catenin activities. Our findings suggest that EOPK exerts its anticancer activity via the inhibition of PAK1 expression, suggesting it may be a potent chemotherapeutic agent for colorectal cancer.
PMCID: PMC4138364  PMID: 25074784
EOPK; PAK1; Colorectal cancer; Proliferation; Migration
10.  Inhibition of 15-hydroxyprostaglandin dehydrogenase by Helicobacter pylori in Human Gastric Carcinogenesis 
Helicobacter pylori (H pylori) infection induces a chronic inflammatory response, which promotes gastric carcinogenesis. 15-hydroxyprostaglandin dehydrogenase (15–PGDH) plays a key role as a tumor suppressor in gastrointestinal cancers. The aim of this study was to elucidate the role of 15-PGDH in gastric carcinogenesis associated with H pylori. 15-PGDH expression in gastric biopsies from H pylori-infected (n=25) and non-infected (n=15) subjects was analyzed by quantitative real-time PCR, western blot analysis, and immunohistochemisty. 15-PGDH DNA methylation was evaluated by methylation specific PCR and pyrosequencing. The expression of 15-PGDH, Snail, ERK1/2, TLR4 and MyD88 in response to H pylori infection was assessed by immunoblot analysis. Compared to negative specimens, H pylori positive specimens had 2-fold lower 15-PGDH mRNA levels and significantly less 15-PGDH protein. In four H pylori infected subjects with longitudinal follow-up, the suppression of 15-PGDH expression was reversed by H pylori eradication therapy. In parallel with suppressing 15-PGDH expression, H pylori infection activated expression of TLR4 and MyD88 expression, increased levels of phospho-ERK1/2, and increased expression of epidermal growth factor receptor (EGFR)-Snail. Inhibition of Snail and MyD88 reversed suppression of 15-PGDH expression and small interfering Myd88 reduced phosphorylated ERK1/2. Similarly, treatment with an ERK1/2 and EGFR inhibitor also restored 15-PGDH expression. Heliocobacter pylori appeared to promote gastric carcinogenesis by suppressing15-PGDH. This process is mediated by the TLR4/MyD88 pathway via ERK1/2 or EGFR - Snail transcriptional regulation. 15-PGDH may be a useful marker and a potential therapeutic target in H pylori-induced gastric carcinogenesis.
PMCID: PMC3796116  PMID: 23430757
Gastric cancer; Helicobacter pylori; 15-prostaglandin dehydrogenase
11.  Technique of Functional and Motility Test: How to Perform Biofeedback for Constipation and Fecal Incontinence 
Biofeedback therapy is an instrument-based learning process centered on operant conditioning. The goal of biofeedback therapy in defecatory disorders is to strengthen the pelvic floor muscles, retrain rectal sensation and coordinate pelvic floor muscles during evacuation. Biofeedback therapy, in a broader sense, includes education, counseling, and diaphragmatic muscle training as well as exercise, sensory, and coordination training. For dyssynergic defecation, biofeedback therapy is a well-known and useful treatment option that had response rates of approximately 70-80% in randomized controlled trials. Biofeedback therapy for dyssynergic defecation consists of improving the abdominal push effort together with biofeedback technique-guided pelvic floor relaxation followed by simulated defecation and/or sensory training. For fecal incontinence, the results of a randomized controlled trial, which had a response rate of 76%, indicated that biofeedback therapy is useful in selected patients who fail to respond to conservative treatment and that training to enhance rectal discrimination of sensation may be helpful in reducing fecal incontinence. The focus of biofeedback therapy for fecal incontinence is on exercising external sphincter contractions under instant feedback, either alone or synchronously with rectal distension and/or sensory training. Biofeedback therapy is a safe treatment that may produce durable improvement beyond the active treatment period; however, a well-designed study to establish a standard protocol for biofeedback therapy is needed. This review discusses the technique of biofeedback therapy to achieve the goal and clinical outcomes for constipation and fecal incontinence.
PMCID: PMC3816189  PMID: 24199015
Biofeedback; Constipation; Dyssynergic defecation; Fecal incontinence; Treatment outcome
12.  Molecular Cloning, Sequence Characterization and Expression Analysis of a CD63 Homologue from the Coleopteran Beetle, Tenebrio molitor 
CD63, a member of the tetraspanin membrane protein family, plays a pivotal role in cell growth, motility, signal transduction, host-pathogen interactions and cancer. In this work, the cDNA encoding CD63 homologue (TmCD63) was cloned from larvae of a coleopteran beetle, Tenebrio molitor. The cDNA is comprised of an open reading frame of 705 bp, encoding putative protein of 235 amino acid residues. In silico analysis shows that the protein has four putative transmembrane domains and one large extracellular loop. The characteristic “Cys-Cys-Gly” motif and “Cys188” residues are highly conserved in the large extracellular loop. Phylogenetic analysis of TmCD63 revealed that they belong to the insect cluster with 50%–56% identity. Analysis of spatial expression patterns demonstrated that TmCD63 mRNA is mainly expressed in gut and Malphigian tubules of larvae and the testis of the adult. Developmental expression patterns of CD63 mRNA showed that TmCD63 transcripts are detected in late larval, pupal and adult stages. Interestingly, TmCD63 transcripts are upregulated to the maximum level of 4.5 fold, in response to DAP-type peptidoglycan during the first 6 h, although other immune elicitors also caused significant increase to the transcript level at later time-points. These results suggest that CD63 might contribute to T. molitor immune response against various microbial pathogens.
PMCID: PMC3821641  PMID: 24132157
molecular cloning; CD63; TM4SF; expression analysis; Tenebrio molitor; immune elicitors
13.  Essential Oil of Pinus koraiensis Exerts Antiobesic and Hypolipidemic Activity via Inhibition of Peroxisome Proliferator-Activated Receptors Gamma Signaling 
Our group previously reported that essential oil of Pinus koraiensis (EOPK) exerts antihyperlipidemic effects via upregulation of low-density lipoprotein receptor and inhibition of acyl-coenzyme A. In the present study, we investigated the antiobesity and hypolipidemic mechanism of EOPK using in vitro 3T3-L1 cells and in vivo HFD-fed rats. EOPK markedly suppressed fat accumulation and intracellular triglyceride associated with downregulation of adipogenic transcription factor expression, including PPARγ and CEBPα in the differentiated 3T3-L1 adipocytes. Additionally, EOPK attenuated the expression levels of FABP and GPDH as target genes of PPARγ during adipocyte differentiation. Furthermore, PPARγ inhibitor GW9662 enhanced the decreased expression of FABP and PPARγ and fat accumulation induced by EOPK. To confirm the in vitro activity of EOPK, animal study was performed by administering normal diet, HFD, and/or EOPK at the dose of 100 or 200 mg/kg for 6 weeks. Consistently, EOPK significantly suppressed body weight gain, serum triglyceride, total cholesterol, LDL cholesterol, and AI value and increased HDL cholesterol in a dose-dependent manner. Immunohistochemistry revealed that EOPK treatment abrogated the expression of PPARγ in the liver tissue sections of EOPK-treated rats. Taken together, our findings suggest that EOPK has the antiobesic and hypolipidemic potential via inhibition of PPARγ-related signaling.
PMCID: PMC3753736  PMID: 23997801
14.  15-Hydroxyprostaglandin Dehydrogenase in Colorectal Mucosa as a Potential Biomarker for Predicting Colorectal Neoplasms 
Journal of Korean Medical Science  2013;28(8):1154-1160.
15-Hydroxyprostaglandin dehydrogenase (15-PGDH) is downregulated during the early stages of colorectal carcinogenesis. The aim of the present study was to investigate the potential role of 15-PGDH in normal-appearing colorectal mucosa as a biomarker for predicting colorectal neoplasms. We obtained paired tumor and normal tissues from the surgical specimens of 32 sporadic colorectal cancer patients. mRNA expression of 15-PGDH was measured using a quantitative real-time PCR assay. We evaluated the association between 15-PGDH mRNA expression in normal-appearing mucosa, the presence of synchronous adenoma, and the cumulative incidence of metachronous adenoma. The relative 15-PGDH expression of normal-appearing mucosa in patients with synchronous adenoma was significantly lower than in patients without synchronous adenoma (0.71 vs 1.00, P = 0.044). The patients in the lowest tertile of 15-PGDH expression in normal-appearing mucosa were most likely to have synchronous adenoma (OR: 10.5, P = 0.024). Patients with low 15-PGDH expression in normal-appearing mucosa also demonstrated more advanced stage colorectal cancer (P = 0.045). However, there was no significant difference in the cumulative incidence of metachronous adenoma according to 15-PGDH mRNA expression in normal-appearing mucosa (P = 0.333). Hence, 15-PGDH in normal-appearing colorectal mucosa can be a useful biomarker of field effect for the prediction of sporadic synchronous neoplasms.
PMCID: PMC3744702  PMID: 23960441
15-Hydroxyprostaglandin Dehydrogenase; Biological Markers; Colorectal Neoplasms
15.  Particled Mica, STB-HO has chemopreventive potential via G1 arrest, and inhibition of proliferation and vascular endothelial growth factor receptor 2 in HCT colorectal cancer cells 
Though Mica, a thin and sheet like mineral, has been used as a mineral medicine for treatment of bleeding, dysentery and inflammation in traditional medicine including Ayurveda, the biological evidences of Mica were not clearly elucidated so far. Thus, in the present study, the antitumor mechanism of particled Mica (STB-HO) was examined in colorectal cancers.
Athymic nude mice were inoculated with HCT116 colon cancer cells and orally administered STB-HO daily for 41 days, and HCT116 and human umbilical vein endothelial cells (HUVECs) were treated with STB-HO for 0 ~ 24 hours to perform immunoblotting, cytotoxicity assay, FACs analysis and measurement of matrix metalloproteinase 9 (MMP-9) secretion and other experiments. Significant differences of all date were evaluated using Student’s t-test and a Turkey-Kramer multiple-comparison post test.
STB-HO significantly suppressed the tumor volume and weight in athymic nude mice inoculated with HCT116 cells at a dose of 100 mg/kg. Thus, the in vivo antitumor mechanism of STB-HO was to elucidated in vitro as well. STB-HO exerted cytotoxicity in HCT116, SW620 and HCT15 colorectal cancer cells. Also, STB-HO increased G1 cell population in a time and concentration dependent manner, enhanced the expression of p21, p27, p53 as cyclin dependent kinase (CDK) inhibitors, attenuated the expression of proliferating cell nuclear antigen (PCNA) and cyclin D1 and also reduced the production of vascular endothelial growth factor (VEGF) and matrix metalloproteinase 9 (MMP-9) in HCT116 cells. Consistently, STB-HO suppressed the phosphorylation of VEGFR2 in HCT116, SW620 and HCT15 cells. Also, STB-HO inhibited the VEGF mediated proliferation and also attenuated the phosphorylation of VEGFR2 and Akt in human umbilical vein endothelial cells (HUVECs).
Collectively, these findings suggest that STB-HO has chemopreventive potential via G1 arrest and inhibition of proliferation and VEGFR2 in HCT116 colorectal cancer cells.
PMCID: PMC3765551  PMID: 23883349
Mica; VEGFR; Colon cancer; G1 arrest; Cell proliferation
16.  Electrical Stimulation Therapy in Chronic Functional Constipation: Five Years' Experience in Patients Refractory to Biofeedback Therapy and With Rectal Hyposensitivity 
Biofeedback therapy (BFT) can be unsuccessful in constipated patients, even those with pelvic floor dysfunction. Electrical stimulation therapy (EST) has been introduced as a novel therapeutic modality in patients with chronic constipation, especially those who have rectal hyposensitivity. We evaluated the efficacy of EST based on five years' clinical experience.
From January 2002 to February 2007, 159 patients underwent EST. After exclusion of 12 drop-outs, 147 (M:F = 61:86, 49 ± 17 years) finished all treatment sessions. Among them, 88 (M:F = 29:59, 49 ± 17 years) were refractory to BFT without rectal hyposensitivity (RH), and 59 (M:F = 32:27, 54 ± 17 years) were those with RH.
The overall response to EST was 59.2% (87/147) by per-protocol analysis. In the EST-responsive group, overall satisfaction improved significantly (from 7.3 ± 3.0 to 4.3 ± 2.5, P < 0.05). Subgroup analysis showed that the response rate was 64.8% (57/88) in patients refractory to BFT without RH, and 50.8% (30/59) in those with RH.
EST may have additional therapeutic efficacy in patients who are refractory to BFT. EST may also be effective in patients with RH, including restoration of rectal sensation. Therefore, EST could be considered as an alternative choice in patients refractory to BFT and with or without RH.
PMCID: PMC3714415  PMID: 23875104
Biofeedback; Constipation; Electric stimulation therapy
17.  Inhibition of cyclooxygenase-2-dependent survivin mediates decursin-induced apoptosis in human KBM-5 myeloid leukemia cells 
Cancer letters  2010;298(2):212-221.
We demonstrate that decursin induces apoptosis via regulation of cyclooxygenase-2 (COX-2) and survivin in leukemic KBM-5 cells. By activating an apoptotic machinery, decursin is cytotoxic to KBM-5 cells. In this apoptotic process, decursin can activate caspase family members and triggers PARP cleavage. At the same time, the expression of COX-2 and survivin in the cells is downregulated. Furthermore, decursin is in synergy with COX-2 inhibitor, celecoxib or NS398 for the induction of apoptosis. Overall, these results suggest that decursin, via inhibiting COX-2 and survivin, sensitizes human leukemia cells to apoptosis and is a potential chemotherapeutic agent to treat this disease.
PMCID: PMC3689030  PMID: 20673699
Decursin; Apoptosis; COX-2; Survivin; KBM-5
18.  Melatonin Suppresses the Expression of 45S Preribosomal RNA and Upstream Binding Factor and Enhances the Antitumor Activity of Puromycin in MDA-MB-231 Breast Cancer Cells 
Since the dysregulation of ribosome biogenesis is closely associated with tumor progression, in the current study, the critical role of ribosome biogenesis related signaling was investigated in melatonin and/or puromycin induced apoptosis in MDA-MB-231 breast cancer cells. Despite its weak cytotoxicity, melatonin from 3 mM attenuated the expression of 45S pre-ribosomal RNA (pre-rRNA), UBF as a nucleolar transcription factor, and fibrillarin at mRNA level and consistently downregulated nucleolar proteins such as UBF and fibrillarin at protein level in MDA-MB-231 cells. Furthermore, immunofluorescence assay revealed that UBF was also degraded by melatonin in MDA-MB-231 cells. In contrast, melatonin attenuated the expression of survival genes such as Bcl-xL, Mcl-1, cyclinD1, and cyclin E, suppressed the phosphorylation of AKT, mTOR, and STAT3, and cleaved PARP and activated caspase 3 only at a high concentration of 12 mM. However, combined treatment of melatonin (3 mM) and puromycin (1 μM) synergistically inhibited viability, attenuated the expression of 45S pre-rRNA and UBF, and consistently downregulated UBF, XPO1 and IPO7, procaspase 3, and Bcl-xL in MDA-MB 231 cells. Overall, these findings suggest that melatonin can be a cancer preventive agent by combination with puromycin via the inhibition of 45S pre-rRNA and UBF in MDA-MB 231 breast cancer cells.
PMCID: PMC3638601  PMID: 23690862
19.  Activation of AMP-Activated Protein Kinase α and Extracelluar Signal-Regulated Kinase Mediates CB-PIC-Induced Apoptosis in Hypoxic SW620 Colorectal Cancer Cells 
Here, antitumor mechanism of cinnamaldehyde derivative CB-PIC was elucidated in human SW620 colon cancer cells. CB-PIC significantly exerted cytotoxicity, increased sub-G1 accumulation, and cleaved PARP with apoptotic features, while it enhanced the phosphorylation of AMPK alpha and ACC as well as activated the ERK in hypoxic SW620 cells. Furthermore, CB-PIC suppressed the expression of HIF1 alpha, Akt, and mTOR and activated the AMPK phosphorylation in hypoxic SW620 cells. Conversely, silencing of AMPKα blocked PARP cleavage and ERK activation induced by CB-PIC, while ERK inhibitor PD 98059 attenuated the phosphorylation of AMPKα in hypoxic SW620 cells, implying cross-talk between ERK and AMPKα. Furthermore, cotreatment of CB-PIC and metformin enhanced the inhibition of HIF1α and Akt/mTOR and the activation of AMPKα and pACC in hypoxic SW620 cells. In addition, CB-PIC suppressed the growth of SW620 cells inoculated in BALB/c athymic nude mice, and immunohistochemistry revealed that CB-PIC treatment attenuated the expression of Ki-67, CD34, and CAIX and increased the expression of pAMPKα in CB-PIC-treated group. Interestingly, CP-PIC showed better antitumor activity in SW620 colon cancer cells under hypoxia than under normoxia, since it may be applied to chemoresistance. Overall, our findings suggest that activation of AMPKα and ERK mediates CB-PIC-induced apoptosis in hypoxic SW620 colon cancer cells.
PMCID: PMC3622407  PMID: 23589723
20.  Inhibition of Connexin 26/43 and Extracellular-Regulated Kinase Protein Plays a Critical Role in Melatonin Facilitated Gap Junctional Intercellular Communication in Hydrogen Peroxide-Treated HaCaT Keratinocyte Cells 
Though melatonin was known to regulate gap junctional intercellular communication (GJIC) in chick astrocytes and mouse hepatocytes, the underlying mechanism by melatonin was not elucidated in hydrogen peroxide- (H2O2-) treated HaCaT keratinocyte cells until now. In the current study, though melatonin at 2 mM and hydrogen peroxide (H2O2) at 300 μM showed weak cytotoxicity in HaCaT keratinocyte cells, melatonin significantly suppressed the formation of reactive oxygen species (ROS) in H2O2-treated HaCaT cells compared to untreated controls. Also, the scrape-loading dye-transfer assay revealed that melatonin enhances the intercellular communication by introducing Lucifer Yellow into H2O2-treated cells. Furthermore, melatonin significantly enhanced the expression of connexin 26 (Cx26) and connexin 43 (Cx43) at mRNA and protein levels, but not that of connexin 30 (Cx30) in H2O2-treated HaCaT cells. Of note, melatonin attenuated the phosphorylation of extracellular signal-regulated protein kinases (ERKs) more than p38 MAPK or JNK in H2O2-treated HaCaT cells. Conversely, ERK inhibitor PD98059 promoted the intercellular communication in H2O2-treated HaCaT cells. Furthermore, combined treatment of melatonin (200 μM) and vitamin C (10 μg/mL) significantly reduced ROS production in H2O2-treated HaCaT cells. Overall, these findings support the scientific evidences that melatonin facilitates gap junctional intercellular communication in H2O2-treated HaCaT keratinocyte cells via inhibition of connexin 26/43 and ERK as a potent chemopreventive agent.
PMCID: PMC3518788  PMID: 23243457
21.  The Genome-Wide Expression Profile of 1,2,3,4,6-Penta-O-Galloyl-β-D-Glucose-Treated MDA-MB-231 Breast Cancer Cells: Molecular Target on Cancer Metabolism 
Molecules and Cells  2011;32(2):123-132.
1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG), a polyphenolic compound isolated from Rhus chinensis Mill. PGG has been known to have anti-tumor, anti-angiogenic and anti-diabetic activities. The present study revealed another underlying molecular target of PGG in MDA-MB-231 breast cancer cells by using Illumina Human Ref-8 expression BeadChip assay. Through the Beadstudio v3 micro assay program to compare the identified genes expressed in PGG-treated MDA-MB-231 cells with untreated control, we found several unique genes that are closely associated with pyruvate metabolism, glycolysis/gluconeogenesis and tyrosine metabolism, including PC, ACSS2, ACACA, ACYP2, ALDH3B1, FBP1, PRMT2 and COMT. Consistent with microarray data, real-time RT-PCR confirmed the significant down-regulation of these genes at mRNA level in PGG-treated MDA-MB-231 cells. Our findings suggest the potential of PGG as anticancer agent for breast cancer cells by targeting cancer metabolism genes.
PMCID: PMC3887664  PMID: 21614488
cancer metabolism; MDA-MB-231; microarray; PGG; real-time PCR
22.  Oral administration of penta-O-galloyl-β-D-glucose suppresses triple-negative breast cancer xenograft growth and metastasis in strong association with JAK1-STAT3 inhibition 
Carcinogenesis  2011;32(6):804-811.
There is an urgent clinical need for chemotherapeutic and chemopreventive drugs for triple-negative breast cancer (TNBCa). Extending on our recent work, we hypothesize that the herbal compound 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG) can inhibit the growth and metastasis of TNBCa xenograft and target Janus-activated kinase (JAK)-signal transducer and activator of transcription (STAT) 3-signaling axis. Daily oral gavage of 10 mg PGG/kg body wt decreased MDA-MB-231 xenograft weight by 49.3% (P < 0.01) at 40 days postinoculation, whereas weekly intraperitoneal injections of Taxol at the same dosage resulted in a 21.4% reduction (P > 0.1). PGG treatment also decreased the incidence of lung metastasis. Immunohistochemical staining detected decreased Ki-67 (proliferation) index and increased terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling (apoptosis) index in PGG-treated and Taxol-treated xenografts. However, the CD34 (angiogenesis) index was decreased only in PGG-treated xenografts along with decreased phospho-STAT3. In cell culture of MDA-MB-231 cells, PGG decreased pSTAT3 and its downstream target proteins, decreased its upstream kinase pJAK1 and induced the expression of SHP1, a JAK1 upstream tyrosine phosphatase, within as early as 1 h of exposure. The phosphatase inhibitor pervanadate reversed the PGG-induced downregulation of pSTAT3 and caspase activation. Orally administered PGG can inhibit TNBCa growth and metastasis, probably through anti-angiogenesis, antiproliferation and apoptosis induction. Mechanistically, PGG-induced inhibition of JAK1-STAT3 axis may contribute to the observed in vivo efficacy and the effects on the cellular processes.
PMCID: PMC3106430  PMID: 21289371
23.  Coffee phenolic phytochemicals suppress colon cancer metastasis by targeting MEK and TOPK 
Carcinogenesis  2011;32(6):921-928.
Epidemiological studies suggest that coffee consumption reduces the risk of cancers, including colon cancer, but the molecular mechanisms and target(s) underlying the chemopreventive effects of coffee and its active ingredient(s) remain unknown. Based on serving size or daily units, coffee contains larger amounts of phenolic phytochemicals than tea or red wine. Coffee or chlorogenic acid inhibited CT-26 colon cancer cell-induced lung metastasis by blocking phosphorylation of ERKs. Coffee or caffeic acid (CaA) strongly suppressed mitogen-activated MEK1 and TOPK activities and bound directly to either MEK1 or TOPK in an ATP-noncompetitive manner. Coffee or CaA, but not caffeine, inhibited ERKs phosphorylation, AP-1 and NF-κB transactivation and subsequently inhibited TPA-, EGF- and H-Ras-induced neoplastic transformation of JB6 P+ cells. Coffee consumption was also associated with a significant attenuation of ERKs phosphorylation in colon cancer patients. These results suggest that coffee and CaA target MEK1 and TOPK to suppress colon cancer metastasis and neoplastic cell transformation.
PMCID: PMC3106432  PMID: 21317303
24.  Music Perception Ability of Korean Adult Cochlear Implant Listeners 
Although the cochlear implant (CI) is successful for understanding speech in patients with severe to profound hearing loss, listening to music is a challenging task to most CI listeners. The purpose of this study was to assess music perception ability and to provide clinically useful information regarding CI rehabilitation.
Ten normal hearing and ten CI listeners with implant experience, ranging 2 to 6 years, participated in the subtests of pitch, rhythm, melody, and instrument. A synthesized piano tone was used as musical stimuli. Participants were asked to discriminate two different tones during the pitch subtest. The rhythm subtest was constructed with sets of five, six, and seven intervals. The melody & instrument subtests assessed recognition of eight familiar melodies and five musical instruments from a closed set, respectively.
CI listeners performed significantly poorer than normal hearing listeners in pitch, melody, and instrument identification tasks. No significant differences were observed in rhythm recognition between groups. Correlations were not found between music perception ability and word recognition scores.
The results are consistent with previous studies that have shown that pitch, melody, and instrument identifications are difficult to identify for CI users. Our results can provide fundamental information concerning the development of CI rehabilitation tools.
PMCID: PMC3369983  PMID: 22701773
Cochlear implant; Music perception; Korean cochlear implant listener
25.  Effects of Electrical Stimulation Rate on Speech Recognition in Cochlear Implant Users 
Korean Journal of Audiology  2012;16(1):6-9.
Background and Objectives
The stimulus signals delivered in cochlear implant (CI) systems are generally derived by sampling the temporal envelope of each channel at some constant rate and using its intensity to control the stimulation current level delivered to the corresponding electrode site. The objective of the study was to investigate speech recognition performance of cochlear implant users in quiet and noisy environments using either moderate or high rates of electrical stimulations.
Materials and Methods
Six post-lingually deafened adult users of the Nucleus CI24 cochlear implant (Contour® electrode array, Cochlear™, Macquarie Park, Australia) with the Freedom® speech processor participated in the study. Stimulation rates of 900 and 2400 pulses-per-second/channel (pps/ch) were used after both stimulation programs were balanced for loudness. Monosyllabic word and sentence recognition scores in quiet and noisy environments were evaluated for each stimulation program after two months of practice. Subjects were also asked to respond to a questionnaire to examine their preference to any stimulation rate in different hearing conditions.
Word recognition scores for monosyllabic words in quiet conditions with the 900 stimulation rate was better than that of the 2400 stimulation rate, although no significant differences between them were found for sentence test in noise. A survey questionnaire indicated that most subjects preferred the 900 stimulation rate to the 2400 stimulation rate, especially in quiet conditions.
Most subjects indicated a preference for 900 pps/ch rate in quiet conditions. It is recommended to remap at 900 pps/ch for those CI users whose performance in quiet conditions is less than ideal.
PMCID: PMC3936531  PMID: 24653862
Cochlear implants; Speech perception; Rehabilitation of hearing impaired

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