Jin-Hyeok Hwang

Seoul National University Bundang Hospital, Sŏul, Seoul, South Korea

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Publications (83)178.91 Total impact

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    ABSTRACT: Long-term outcomes of symptomatic gallbladder (GB) sludge are not fully established. This study aimed to determine whether patients with symptomatic GB sludge could experience subsequent biliary events.
    Journal of clinical gastroenterology. 08/2014;
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    ABSTRACT: The durability of off-treatment virologic responses has not been fully elucidated in chronic hepatitis B (CHB) patients who have previously achieved complete virologic suppression with nucleos(t)ide analog (NA) therapy. This study aimed to assess off-treatment virologic relapse rates and to characterize the outcomes of subsequent re-treatment in CHB patients who have discontinued oral NA following complete virologic suppression.
    BMC Infectious Diseases 08/2014; 14(1):439. · 3.03 Impact Factor
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    ABSTRACT: To investigate the prognostic factors determining the success rate of non-surgical treatment in the management of post-operative bile duct injuries (BDIs).
    World journal of gastroenterology : WJG. 06/2014; 20(22):6924-31.
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    ABSTRACT: The objectives of this study were to study the expression status of markers associated with epithelial-to-mesenchymal transition (EMT) and metastasis in pancreatic ductal adenocarcinomas (PDACs) and to explore the prognostic value of these markers. Immunohistochemical stains for CD24, CD44, E-cadherin, N-cadherin, Snail, S100A4, Vimentin, urokinase-type plasminogen activator receptor, Ezrin, and matrix metalloproteinase 2 were performed on 67 resected PDACs. Proteins associated with EMT and metastasis were more frequently expressed in PDACs with poor differentiation, higher tumor stage, and lymphatic and perineural invasion. CD24 expression was associated with frequent expression of EMT markers (CD44 [P = 0.004], S100A4 [P < 0.001], Vimentin [P = 0.022], urokinase-type plasminogen activator receptor [P = 0.002], and Ezrin [P = 0.010]). CD24 and S100A4 expressions in PDAC were significant prognostic factors for early tumor recurrence (hazard risk [HR], 5.185 and 2.490, P = 0.048 and 0.009, respectively) and poor survival (HR, 11.977 and 3.202, P = 0.006 and 0.004, respectively). In addition, the interaction between CD24 and S100A4 expression status was a significant prognostic factor for poor survival (HR, 18.518, P = 0.003). The expression of markers of EMT and metastasis in PDACs was significantly associated with pathologic features of aggressiveness. CD24 and S100A4 expressions were significant predictors of poor survival; thus, immunohistochemistry for these markers in resected specimens may help to identify PDAC patients with a poor prognosis.
    Pancreas 04/2014; 43(3):380-8. · 2.95 Impact Factor
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    ABSTRACT: Background and study aim: The combination of midazolam and opioid has been widely used as a standard sedative regimen for endoscopic retrograde cholangiopancreatography (ERCP). Following recent evidence that dexmedetomidine may exert a synergistic effect in combination with midazolam, this study compared the sedative effect and adverse events of midazolam - meperidine - dexmedetomidine (MMD) and midazolam - meperidine during ERCP. Patients and methods: A total of 110 patients who were scheduled for ERCP were prospectively enrolled and randomly assigned, in a double-blind manner, to the MMD (n = 53) or midazolam - meperidine (n = 57) groups. Each patient received an intravenous (IV) bolus dose of midazolam and meperidine (0.06 mg/kg and 50 mg, 30 % reduction and 25 mg for patients aged ≥ 65 years, respectively). To this dose, a continuous IV infusion of dexmedetomidine (1 μg/kg/h; MMD group) or the same volume of normal saline (midazolam - meperidine group) was added. The sedation level (Ramsay Sedation Scale [RSS]) as well as hemodynamic and respiratory changes were assessed. Results: Adequate sedation (RSS ≥ 3) was maintained during ERCP in 75.5 % and 36.8 % of the MMD and midazolam - meperidine group, respectively (P < 0.001). RSS scores were significantly higher in the MMD group (P < 0.001). Intraoperative bispectral index scores were significantly lower in the MMD group (P < 0.001) than in the midazolam - meperidine group. Lower additional (P = 0.001) and total (P = 0.003) doses of midazolam were required in the MMD group. Patients in the MMD group showed lower pain scores (P < 0.001) and higher satisfaction scores (P < 0.001). Desaturation occurred more frequently in the midazolam - meperidine group (11 vs. 1; P = 0.003). Conclusions: The addition of dexmedetomidine to the midazolam - meperidine regimen provided better sedative efficacy and a superior safety profile during ERCP compared with a midazolam - meperidine regimen.This trial was registered at ClinicalTrials.gov Identifier (NCT01404689).
    Endoscopy 04/2014; 46(4):291-8. · 5.74 Impact Factor
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    ABSTRACT: Background/Aims: It has been demonstrated that cryptogenic pyogenic liver abscess (PLA) is associated with colonic mucosal defect, especially colorectal cancer (CRC). Therefore, the screening of CRC in patients with cryptogenic PLA is important. This study was to investigate whether computed tomographic colonography (CTC) has value as a follow-up modality as well as CRC screening tool in patients with PLA. Methods: A retrospective evaluation of 109 patients with cryptogenic PLA who underwent CTC or colonoscopy for CRC screening between July 2005 and July 2012 was performed. The patients were divided into a CTC group (n = 68) and colonoscopy group (n = 41) after treatment of liver abscess, and compared concerning the detection rate of advanced neoplasia, consisting of advanced adenomas and invasive carcinomas. Patients with advanced polyps in CTC surveillance underwent subsequent colonoscopy. Results: Advanced colonic neoplasia was detected in 9 of the 68 patients (13.2%) in the CTC group and 8 of the 41 patients (19.5%) in the conventional colonoscopy group (p = 0.42). The treatment response of all abscess lesions was clearly visualized on CTC, with complete resolution in 17.6% (12/68) of patients. After adjustment for sex and pathogens, old age (≥65 years) was significantly associated with advanced neoplasia (OR 5.481; 95% CI 1.757-17.100; p = 0.03). Conclusion: CTC has a valuable dual role as a follow-up modality and in the screening of CRC in patients with cryptogenic PLA, particularly in elderly patients over 65 years of age. © 2014 S. Karger AG, Basel.
    Digestion 04/2014; 89(3):175-183. · 1.94 Impact Factor
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    ABSTRACT: Fascioliasis is a zoonotic infection caused by Fasciola hepatica or Fasciola gigantica. We report an 87-year-old Korean male patient with postprandial abdominal pain and discomfort due to F. hepatica infection who was diagnosed and managed by endoscopic retrograde cholangiopancreatography (ERCP) with extraction of 2 worms. At his first visit to the hospital, a gallbladder stone was suspected. CT and magnetic retrograde cholangiopancreatography (MRCP) showed an intraductal mass in the common bile duct (CBD) without proximal duct dilatation. Based on radiological findings, the presumed diagnosis was intraductal cholangiocarcinoma. However, in ERCP which was performed for biliary decompression and tissue diagnosis, movable materials were detected in the CBD. Using a basket, 2 living leaf-like parasites were removed. The worms were morphologically compatible with F. hepatica. To rule out the possibility of the worms to be another morphologically close species, in particular F. gigantica, 1 specimen was processed for genetic analysis of its ITS-1 region. The results showed that the present worms were genetically identical (100%) with F. hepatica but different from F. gigantica.
    The Korean Journal of Parasitology 04/2014; 52(2):193-6. · 0.88 Impact Factor
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    ABSTRACT: Hilar cholangiocarcinoma is a tumor of the extrahepatic bile duct involving the left main hepatic duct, the right main hepatic duct, or their confluence. Biliary drainage in hilar cholangiocarcinoma is sometimes clinically challenging because of complexities associated with the level of biliary obstruction. This may result in some adverse events, especially acute cholangitis. Hence the decision on the indication and methods of biliary drainage in patients with hilar cholangiocarcinoma should be carefully evaluated. This review focuses on the optimal method and duration of preoperative biliary drainage (PBD) in resectable hilar cholangiocarcinoma. Under certain special indications such as right lobectomy for Bismuth type IIIA or IV hilar cholangiocarcinoma, or preoperative portal vein embolization with chemoradiation therapy, PBD should be strongly recommended. Generally, selective biliary drainage is enough before surgery, however, in the cases of development of cholangitis after unilateral drainage or slow resolving hyperbilirubinemia, total biliary drainage may be considered. Although the optimal preoperative bilirubin level is still a matter of debate, the shortest possible duration of PBD is recommended. Endoscopic nasobiliary drainage seems to be the most appropriate method of PBD in terms of minimizing the risks of tract seeding and inflammatory reactions.
    World journal of gastrointestinal endoscopy. 03/2014; 6(3):68-73.
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    ABSTRACT: Background/Aims: There is no standard consensus on a strategy in the second-line setting for gemcitabine-refractory advanced pancreatic cancer. This study evaluated the activity and tolerability of oxaliplatin, irinotecan, 5-fluorouracil and leucovorin (FOLFIRINOX) as a second-line therapy in advanced pancreatic adenocarcinoma pretreated with a gemcitabine-based regimen. Methods: A retrospective survey was carried out on 18 patients with advanced pancreatic cancer who had been on gemcitabine-based chemotherapy and were then treated with FOLFIRINOX as a second-line therapy. Results: One patient (5.6%) had a confirmed complete response, 4 (22.2%) had confirmed partial responses and 5 (27.8%) had stable disease, resulting in a rate of disease control of 55.6% (95% CI, 33.3-77.8%). The median progression-free survival and median survival were 2.8 months and 8.4 months, respectively. Seven patients (38.9%) experienced grade 3-4 neutropenia. Grade 3 or 4 nonhematologic adverse events included nausea (38.9%) and vomiting (16.7%). Conclusions: These results suggest the modest clinical activity regarding efficacy and the acceptable toxicity profile with the FOLFIRINOX regimen as a second-line treatment. © 2014 S. Karger AG, Basel.
    Chemotherapy 01/2014; 59(4):273-279. · 2.07 Impact Factor
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    ABSTRACT: Achalasia is classified into 3 types according to the Chicago classification. The aim of this study was to investigate characteristics and treatment outcomes of 3 achalasia subtypes in Korean patients. Fifty-five patients diagnosed with achalasia based on conventional or high-resolution esophageal manometry were consecutively enrolled. Their clinical characteristics, manometric, endoscopic and esophagographic findings and treatment responses were analyzed among the 3 subtypes of achalasia. Of 55 patients, 21 (38.2%) patients had type I, 28 (50.9%) patients had type II and 6 (10.9%) patients had type III. The median follow-up period was 22.4 (interquartile range, 3.6-67.4) months. Type III patients were older than type I and II patients (70.0 vs. 46.2 and 47.6 years, P = 0.023). The width of the esophagus in type I patients was wider with more frequent bird's beak appearance on esophagogram than the other 2 types (P = 0.010 and 0.006, respectively). Of the 50 patients who received the evaluation for treatment response at 3 months, 7 patients (36.8% vs. 26.9%) were treated with pneumatic dilatation and 4 patients (21.1% vs. 15.4%) with laparoscopic Heller's myotomy in type I and II groups, respectively. The treatment responses of pneumatic dilatation and Heller's myotomy in type I group were 71.4 and 50.0% and in type II were 85.7 and 75.0%, respectively, and all 5 patients in type III group showed good response to medical therapy. Clinical characteristics of 3 achalasia subtypes in Korean patients are consistent with other studies. Treatment outcomes are variable among 3 subtypes.
    Journal of neurogastroenterology and motility 10/2013; 19(4):485-94.
  • Jaihwan Kim, Jin-Hyeok Hwang
    The Korean journal of gastroenterology = Taehan Sohwagi Hakhoe chi 10/2013; 62(4):256-9.
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    ABSTRACT: Immunoglobulin G4 (IgG4)-related disease is a novel disease entity that can involve diverse organs, causing specific diseases, including autoimmune pancreatitis, sclerosing cholangitis, cholecystitis, inflammatory aortic aneurysm, and inflammatory pseudotumor. IgG4-related disease is characterized by elevated serum IgG4 concentrations, abundant IgG4 lymphoplasmacytic infiltration, and dramatic steroid responses. It is clinically important to differentiate this rare disease from primary sclerosing cholangitis and cholangiocarcinoma, because the treatment and prognosis of these two diseases are completely different. However, the preoperative diagnosis is challenging, and the disease is frequently misdiagnosed. If the serum level of IgG4 is within the normal range, the diagnosis of IgG4-related disease is more difficult. This article reports on a 59-year-old man with IgG4-related disease mimicking unresectable gallbladder cancer with normal serum IgG4 concentrations.
    Gut and liver 09/2013; 7(5):616-20. · 1.31 Impact Factor
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    ABSTRACT: No standard chemotherapy has been established for advanced gallbladder cancer. The authors studied the activity and tolerability of a gemcitabine and oxaliplatin (GEMOX) combination in unresectable gallbladder cancer (GBC). Adult patients with pathologically confirmed unresectable GBC were prospectively recruited at three centers. No patient had received prior chemotherapy or radiotherapy. Patients received cycles of gemcitabine at 1,000 mg/m(2) on day 1, followed by oxaliplatin at 100 mg/m(2) on day 2, every 2 weeks. The primary study endpoint was time to progression. Forty patients with unresectable GBC were enrolled. The median age was 60 years (range, 38 to 79 years). All patients showed good performance status. Of the 33 analyzable patients, 12 achieved partial response (36%), 17 stable disease (52%), and four progressive disease (12%). No patient achieved a complete response. The tumor control rate was 88%. At a median follow-up of 6.8 months, the median time to progression was 5.3 months (95% confidence interval [CI], 3.7 to 6.9), and median overall survival was 6.8 months (95% CI, 6.1 to 7.5). Nine of the 40 patients (23%) experienced at least a grade-3 adverse event, but no patient experienced a grade-4 adverse event. GEMOX combination therapy is a feasible option and is well tolerated in unresectable GBC.
    Gut and liver 09/2013; 7(5):594-8. · 1.31 Impact Factor
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    ABSTRACT: Abstract Background: Nonsurgical biliary drainage is considered as a priority for obstructive jaundice associated with unresectable hepatocellular carcinoma (HCC). Successful drainage allows the patient to receive antitumor therapy, such as transarterial chemoembolization (TACE). However, only limited data are available on clinical outcomes in patients who treated biliary drainage with subsequent TACE. Objective: This study evaluated the clinical outcome of biliary drainage with subsequent TACE in unresectable HCC patients with obstructive jaundice. Design: This was a retrospective study. Setting/subjects: A total of 60 patients received endoscopic biliary drainage (ERBD) or percutaneous transhepatic biliary drainage (PTBD) in two tertiary care referral centers. Measurements: Successful drainage and survival were measured. Results: Successful drainage was achieved in 39 (65%) patients. The median survival of 39 patients in whom successful drainage was achieved, regardless of which procedure was performed, was much longer than that of 21 patients without successful drainage (147 days versus 38 days, respectively, P<.001). In particular, the median survival was longer in 17 patients who underwent TACE after achieving successful drainage than in 22 patients who were treated conservatively after achieving successful drainage (410 days versus 77 days, respectively, P<.001). Multivariable analysis in 39 patients in the successful drainage group showed that TACE (hazard ratio 0.15; 95% confidence interval 0.05-0.45, P=.001) was an independent predictive factor of a favorable outcome. Conclusions: Effective palliation by successful biliary drainage with subsequent TACE might prolong the survival in patients with obstructive jaundice caused by unresectable HCC.
    Journal of palliative medicine 07/2013; · 1.84 Impact Factor
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    ABSTRACT: Small interfering RNAs not only modulate gene expression at a post-transcriptional level, but also induce transcriptional gene silencing by RNA interference-mediated heterochromatin formation and RNA-directed DNA methylation (RdDM). However, although established in plants, there have been controversies whether RdDM operates in mammals. Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) serves as a template for viral RNA transcription, and transcriptional activity of HBV cccDNA is regulated by methylation in patients with chronic HBV infection. In this study, we stably expressed short hairpin RNA (shRNA) against HBV in human hepatoma cells to determine whether shRNA induces methylation of HBV cccDNA. HepAD38 cells which permit replication of HBV under control of tetracycline-responsive promoter were transduced with lentiviral vectors which encode sh-1580, a shRNA against the hepatitis B viral protein HBx. Bisulfite sequencing PCR analysis revealed that sh-1580 induced CpG methylations at a higher rate compared to control (31.3% vs. 12.8%, p < 0.05). The sh-1580-induced CpG methylation was localized near the target sequence of sh-1580 in more than a half of the clones. Methylation-induced transcriptional suppression was confirmed by in vitro transcription assay. These results confirm the feasibility of RdDM of HBV cccDNA in human cells. Lentiviral vector-mediated transfer of shRNA may be used as a tool for novel transcriptional modulation by epigenetic modification of HBV cccDNA.
    Biochemical and Biophysical Research Communications 06/2013; 436(2):152–155. · 2.28 Impact Factor
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    ABSTRACT: BACKGROUND: Despite routine preoperative biliary drainage (PBD) with periampullary cancer, its optimal duration has not been established. The objective of this study was to investigate PBD in severely jaundiced patients. METHODS: A total of 120 patients with periampullary tumors who underwent surgery with intent to cure after PBD for severe obstructive jaundice were enrolled. According to the duration of PBD, 66 and 54 patients were classified into the long-term (≥2 weeks) and short-term (<2 weeks) groups. RESULTS: PBD-related complications occurred in 6 (9.1%) and 14 (25.9%) patients in the short-term and long-term groups, respectively (P = .014). Rates of surgery-related complications and mortalities were not significantly different between the 2 groups. The R0 resection rate tended to be lower (P = .054) and the mean length of hospital stay was significantly longer (P = .039) in the long-term group. CONCLUSIONS: PBD duration <2 weeks is more appropriate in severely jaundiced patients with periampullary cancer.
    American journal of surgery 05/2013; · 2.36 Impact Factor
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    ABSTRACT: BACKGROUND AND AIM: Propensity score indicates a probability of having a confounding factor. It is used to match each patient with the closest propensity score between two groups, which is known as propensity score matching. This study aimed to evaluate the gallstone-related biliary events, defined as biliary colic and acute cholecystitis between coronary artery disease (CAD) and non-CAD patients using propensity score matching. METHODS: This retrospective cohort study evaluated 267 asymptomatic gallstone patients with CAD and 459 asymptomatic gallstone patients without CAD from March 2003 to December 2009 at two tertiary teaching hospitals in the Republic of Korea. After propensity score matching, total 378 patients, including 126 in study group (with CAD) and 252 in control group (without CAD), were evaluated. RESULTS: During a median follow up of 47 months, overall gallstone-related biliary event rate was 33.5% in the study group and 27.5% in the control group. The five-year cumulative rates were 25.3% vs. 17.7% in gallstone-related biliary event and 10.9% vs. 1.6% in acute cholecystitis (study vs. control group). After propensity score adjustment, the risk of gallstone-related biliary events in the CAD patients significantly increased [Hazard ratio (HR) 2.11, 95% confidence interval (CI) 1.14 to 3.90, P=0.017 in matched patients]. CONCLUSION: In patients with asymptomatic gallstones, the co-existence of CAD can increase the risk of gallstone-related biliary events, particularly acute cholecystitis. Therefore, gallstone patients with CAD should be carefully monitored, even if they are asymptomatic.
    Journal of Gastroenterology and Hepatology 05/2013; · 3.33 Impact Factor
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    ABSTRACT: BACKGROUND: Small stone fragments after an endoscopic stone extraction for choledocholithiasis may act as the nidus for recurrent choledocholithiasis. Therefore, efforts to eliminate the nidus might reduce the recurrence of choledocholithiasis and cholangitis related to choledocholithiasis. AIMS: The purpose of this study was to determine whether an additional preventive saline irrigation of the bile duct after the endoscopic removal of common bile duct stones would decrease residual stones and the recurrence of cholangitis. METHODS: A retrospective analysis was performed for the consecutively collected data about the patients who underwent the complete endoscopic treatment for common bile duct stone. RESULTS: Among 99 patients, 45 patients underwent saline irrigation. Residual stones were detected in 18 patients (18.2 %). The incidences of residual stones were 8.9 % (4 of 45 patients) in the irrigation group and 25.9 % (14 of 54 patients) in the non-irrigation group (P = 0.037). In multivariate analysis, preventive saline irrigation was found to be the only significant factor for the decrease of residual stones (HR = 0.258, P = 0.039). When analyzing the occurrence of recurrent cholangitis and the procedure related to complications, there were no significant differences according to the performance of preventive saline irrigation of the bile duct. CONCLUSIONS: Preventive saline irrigation could reduce the residual common bile duct stones without complications.
    Digestive Diseases and Sciences 04/2013; · 2.26 Impact Factor
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    ABSTRACT: BACKGROUNDAIMS: This study evaluated the effect of Helicobacter pylori eradication on functional dyspepsia (FD), and the relationship between the changes of histological gastritis and FD symptom responses. A total of 213 FD patients diagnosed by Rome III criteria were consecutively enrolled. H. pylori tests and gastritis grade by the Sydney system were performed before and 1 year after the proton pump based-eradication therapy for 7 days. Serum levels of pepsinogen, and genetic polymorphisms IL-6, IL-8 and IL-10 were investigated. Total of 91 patients completed the 1 year follow-up. When the response rate of dyspepsia was compared at 1 year between the non-eradicated group (n = 24) and eradicated group (n = 67), each group showed complete response of 62.5% and 62.7%; satisfactory response (≥ 50%) of 0.0% and 19.4%; partial response (< 50%) of 12.5% and 11.9%; and refractory response of 25.0% and 6.0%, respectively (P = 0.015). In addition, the responder group (complete + satisfactory response) at 1 year showed improvement of activity and chronic inflammation in both the antrum and corpus (all P < 0.001). Multivariate analysis showed that H. pylori eradication (OR, 5.81; 95% CI, 1.07-31.59) and symptom improvement at 3 month (OR, 28.90; 95% CI, 5.29-157.82) were associated with the improvement of dyspepsia at 1 year. Among the successfully eradicated FD patients (n = 67), male (P = 0.013) and higher initial BMI (P = 0.016) were associated with the improvement of dyspepsia at 1 year. H. pylori eradication improved FD symptoms, as well as gastritis at 1 year, suggesting that inflammation mediates FD.
    Journal of neurogastroenterology and motility 04/2013; 19(2):233-43.
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    ABSTRACT: Background/Aim: Overexpression of microRNA-21 (miR-21) indicates chemoresistance in pancreatic cancer. We evaluated the change of chemosensitivity to gemcitabine through the down-regulation of miR-21 in human pancreatic cancer cells (Panc-1). The efficacy of indole-3-carbinol (I3C) in suppressing miR-21 expression and its anticancer effect in combination with gemcitabine were investigated. Down-regulation of miR-21 by I3C was positively-correlated in a time- and dose-dependent manner. I3C and gemcitabine combination therapy increased cytotoxicity in Panc-1 cells. Transfection of miR-21 mimic abrogated I3C-induced sensitivity to gemcitabine. DNA fragmentation and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assays showed that pre-treatment with I3C enhanced apoptosis and this effect was attenuated by miR-21 transfection. The expression of programmed cell death-4 (PDCD4) was increased by I3C and reduced by miR-21 transfection. I3C would be effective for enhancing sensitivity of pancreatic cancer cells to gemcitabine via down-regulation of miR-21. Such enhanced chemosensitivity might be explained by the increased expression of PDCD4, which is a downstream target which miR-21 negatively regulates.
    Anticancer research 04/2013; 33(4):1473-81. · 1.71 Impact Factor

Publication Stats

590 Citations
178.91 Total Impact Points

Institutions

  • 2005–2014
    • Seoul National University Bundang Hospital
      • Department of Medicine
      Sŏul, Seoul, South Korea
  • 2013
    • National Cancer Center Korea
      Kōyō, Gyeonggi Province, South Korea
  • 2003–2013
    • Seoul National University Hospital
      • Department of Internal Medicine
      Seoul, Seoul, South Korea
  • 2011
    • Seoul Medical Center
      Sŏul, Seoul, South Korea
  • 2010
    • National Institutes of Health
      • Branch of Medical Oncology Branch and Affiliates
      Bethesda, MD, United States
  • 2006
    • Dongguk University
      • Department of Internal Medicine
      Seoul, Seoul, South Korea