Anticoagulants Are a Risk Factor for Delayed Bleeding after Colorectal Endoscopic Submucosal Dissection: A HASID Multicenter Study.

INTRODUCTION: Delayed bleeding is an important adverse event following colorectal endoscopic submucosal dissection (ESD). However, whether anticoagulants are risk factors for delayed bleeding after colorectal ESD remains debatable. METHODS: We retrospectively analyzed 1,708 patients who underwent colorectal ESDs between January 2015 and December 2020 at five academic medical centers in South Korea. We aimed to identify the risk factors for delayed bleeding in patients after colorectal ESD and, in particular, to evaluate the effect of anticoagulants. RESULTS: Delayed bleeding occurred in 40 of 1,708 patients (2.3%). The risk factors for delayed bleeding were antithrombotic agents (odds ratio [OR], 6.155; 95% confidence interval [CI], 3.201-11.825; p < 0.001), antiplatelet agents (OR, 4.609; 95% CI, 2.200-9.658; p < 0.001), anticoagulants (OR, 8.286; 95% CI, 2.934-23.402; p < 0.001), and tumor location in the rectum (OR, 2.055; 95% CI, 1.085-3.897; p = 0.027). In the analysis that excluded patients taking antiplatelet agents, the delayed bleeding rate was higher in patients taking anticoagulants (1.6% no antithrombotic agents vs. 12.5% taking anticoagulants, p < 0.001). There was no difference in the delayed bleeding rate (4.2% direct oral anticoagulants vs. 25.0% warfarin, p = 0.138) or clinical outcomes according to the type of anticoagulant used. CONCLUSIONS: Anticoagulants use was a risk factor for delayed bleeding after colorectal ESD, and there was no difference in the risk of delayed bleeding based on the type of anticoagulant used. Colorectal ESD in patients receiving anticoagulants requires careful observation and management for delayed bleeding.

The Prognostic Utilities of DNA Mismatch Repair Status and KRAS and BRAF Mutation in Korean Colorectal Cancer Patients: The KASID Multicenter Study.

INTRODUCTION: KRAS, BRAF, and DNA mismatch repair (MMR) mutations aid clinical decision-making for colorectal cancer (CRC) patients. To ensure accurate predictions, the prognostic utilities of these biomarkers and their combinations must be individualized for patients with various TNM stages. METHODS: Here, we retrospectively analyzed the clinicopathological features of 904 Korean CRC patients who underwent CRC surgery in three teaching hospitals from 2011 to 2013; we also assessed the prognostic utilities of KRAS, BRAF, and MMR mutations in these patients. RESULTS: The overall frequencies of KRAS and BRAF mutations were 35.8% and 3.2%, respectively. Sixty-nine patients (7.6%) lacking expression of ≥1 MMR protein were considered MMR protein deficient (MMR-D); the remaining patients were considered MMR protein intact. KRAS mutations constituted an independent risk factor for shorter overall survival (OS) in TNM stage I-IV and stage III patients. BRAF mutations were associated with shorter OS in TNM stage I-IV patients. MMR-D status was strongly positive prognostic in TNM stage I-II patients. DISCUSSION/CONCLUSION: To our knowledge, this is the first multicenter study to explore the prognostic utilities of KRAS, BRAF, and MMR statuses in Korean CRC patients. Various combinations of KRAS, BRAF, and DNA MMR mutations serve as genetic signatures that affect tumor behavior; they are prognostic in CRC patients.

Differences in clinical outcomes according to the time interval between the bridge to surgery stenting and surgery for left-sided malignant colorectal obstruction.

BACKGROUND: Self-expandable metal stent (SEMS) placement is commonly used as a bridge to surgery (BTS) for left-sided malignant colorectal obstruction (MCO). However, the optimal time interval between BTS stenting and surgery for left-sided MCO is unclear, and the results of previous studies are conflicting. This study aimed to determine the differences in clinical outcomes according to the time interval between BTS stenting and surgery in left-sided MCO. METHODS: Data from 594 patients who underwent SEMS placement for MCO between January 2009 and December 2018 were reviewed. Among them, 148 patients who underwent SEMS placement as BTS treatment and curative surgery were enrolled. The enrolled patients were divided into three groups according to the interval between BTS stenting and surgery: group 1 (interval ≤2 weeks), group 2 (interval 2-3 weeks), and group 3 (interval >3 weeks). RESULTS: Group 2 and 3 patients underwent significantly higher rates of laparoscopic surgery than those in group 1 (83.7, 81.0 vs. 53.2 %, respectively; P=0.003, P=0.003, respectively). Also, rates of stoma formation directly after resection were significantly higher in group 1 compared to groups 2 and 3 (21.3 vs 2.3, 6.9%, respectively; P=0.008, P=0.043, respectively). Bridging interval had no effect on SEMS-related complications, resection-related complications, 90-day mortality, permanent stoma formation, 3-year disease-free survival, and 3-year overall survival. CONCLUSIONS: A bridging interval of > 2 weeks between BTS stenting and surgery for left-sided MCO is preferable for lower stoma formation rates and higher rates of laparoscopic approach operation, with no difference in short-term and long-term outcomes including complication, mortality, and survival.

Impact of Endoscopists' Personality Traits on Adenoma and Polyp Detection Rates in Colonoscopy: A KASID Multicenter Study.

BACKGROUND: The personality traits of endoscopists have been suggested to affect the adenoma detection rate (ADR). We thus evaluated the relationship between endoscopists' personality traits and the ADR during colonoscopy using the Minnesota Multiphasic Personality Inventory-2 (MMPI-2). METHODS: In total, 1230 patients (asymptomatic and aged 50-80 years) who underwent screening or surveillance (≥ 5 years) colonoscopy were recruited from 13 university hospitals by 20 endoscopists between September 2015 and December 2017. We retrospectively measured the ADR, polyp detection rate (PDR), and number of adenomas per colonoscopy (APC). All 20 endoscopists completed all 567 true/false MMPI-2 items. RESULTS: The overall mean colonoscopy withdrawal time, PDR, ADR, and APC were 7.3 ± 2.8 min, 55%, 45.3%, and 0.97 ± 1.58, respectively. No significant difference was observed in the MMPI-2 clinical scales (e.g., hypochondriasis and psychasthenia), content scales (e.g., obsessiveness and type A character), or supplementary scales (e.g., dominance and social responsibility) between the high ADR group (ADR ≥45%, n = 10) and the low ADR group (ADR < 45%, n = 10). In multivariate logistic regression analysis, the ADR was associated significantly with patient age and sex. The ADR was related significantly to endoscopists' colonoscopy experience and the per-minute increase in the colonoscopy withdrawal time (OR 1.21, 95% CI 1.06-1.38, p = 0.005). In a logistic regression analysis adjusted for patient factors, the ADR was associated significantly with ego strength (OR 1.04, 95% CI 1.00-1.09, p = 0.044), as measured by the MMPI-2. CONCLUSIONS: With the exception of ego strength, the endoscopists' personality traits were not associated with adenoma or polyp detection.

Relationship between the endoscopic withdrawal time and adenoma/polyp detection rate in individual colonic segments: a KASID multicenter study.

BACKGROUND AND AIMS: Appropriate colonoscopy withdrawal times for individual colonic segments are not well known. The relationship between withdrawal time and adenoma detection rate (ADR)/polyp detection rate (PDR) in individual colonic segments was examined in this study. METHODS: This was a prospective observational study involving 724 patients who underwent colonoscopy screening or surveillance colonoscopy from October 2015 to February 2017 at 10 university hospitals. RESULTS: In the right side of the colon, the ADR (33.2% vs 13.7%, P < .001), PDR, serrated polyp detection rate, and number of adenomas per colonoscopy (APC) were significantly higher when the colonoscopy withdrawal time was ≥2 minutes compared with <2 minutes. When the withdrawal time was ≥4 minutes in the proximal colon and ≥3 minutes in the left segment of the colon, the ADR, PDR, and APC were significantly higher compared with withdrawal times of <4 minutes and <3 minutes, respectively. Multivariate analyses showed that the ADR was significantly associated with withdrawal times of ≥2 minutes in the right side of the colon (odds ratio [OR], 2.98; 95% confidence interval [CI], 1.72-5.15; P < .001), ≥4 minutes in the proximal colon (OR, 4.48; 95% CI, 3.15-6.36; P < .001), and ≥3 minutes in the left segment of the colon (OR, 2.92; 95% CI, 1.74-4.91; P < .001). CONCLUSIONS: The PDR and ADR appeared to be significantly increased when the withdrawal time was ≥2 minutes in the right-sided colon segment, ≥4 minutes in the proximal colon, and ≥3 minutes in the left-sided colon segment compared with shorter withdrawal times.

Clinical outcomes of endoscopic resection for colorectal laterally spreading tumors with advanced histology.

BACKGROUND: Colorectal laterally spreading tumors (LSTs) are large, flat neoplasms that are usually treated using different endoscopic techniques based on their morphology, size, and histology. The aim of this study was to evaluate the clinical outcomes of LSTs with advanced histology treated by endoscopic resection. METHODS: A total of 246 LSTs with advanced histology [i.e., high-grade dysplasia (HGD) and adenocarcinoma (AC)] treated by endoscopic resection [i.e., endoscopic mucosal resection (EMR), EMR-precutting (EMR-P), and endoscopic submucosal dissection (ESD)] were enrolled. Clinicopathological characteristics were collected by review of patient's medical records. RESULTS: The en bloc resection and R0 resection rates were 75.6% and 85.0%, respectively. The bleeding and perforation rates were 10.2% and 2.4%, respectively. The frequency of cancerous pit pattern and bleeding was significantly higher in LSTs with AC than in LSTs with HGD. The R0 resection rate in LSTs with HGD was significantly higher than that in LSTs with AC. The frequency of cancerous pit patterns in LST cases with submucosal AC was significantly higher than those with intramucosal AC. The mean size of the LSTs was significantly larger in ESD group than in EMR or EMR-P groups. The frequencies of nodular mixed subtype, cancerous pit patterns, and en bloc resection rates were significantly higher in the ESD group than in the EMR or EMR-P groups. However, the frequency of perforation was significantly higher in EMR-P group than in EMR or ESD groups. CONCLUSIONS: These results indicate that ESD is a more acceptable treatment approach for resection of colorectal LSTs of larger size, with nodular mixed subtype, having a cancerous pit pattern or AC, using either en bloc or curative resection methods, compared to EMR or EMR-P procedures.

Risk of metachronous neoplasia on surveillance colonoscopy in young patients with colorectal neoplasia.

BACKGROUND AND AIMS: Few prior reports exist that address the appropriate colonoscopy surveillance interval for individuals <50 years old. We compared the risk of metachronous neoplasia between younger (20-49 years) and older (50-54 years) cohorts. METHODS: This multicenter retrospective cohort study compared the incidence of metachronous neoplasia in younger and older cohorts according to baseline risk stratification. Subjects were eligible if they underwent their first colonoscopy between June 2006 and May 2010 and had at least 1 or more surveillance colonoscopy up to June 2015. RESULTS: Among a total of 10,477 subjects who underwent baseline colonoscopy, 9722 were eligible after excluding 755 subjects. Of those 9722 subjects, 43% underwent surveillance colonoscopy. In the baseline high-risk adenoma group (n = 840), the 3-year risk of metachronous advanced neoplasia was 10.7% in the younger patients on screening colonoscopy and 8.9% in the older patients (P > .1). In the baseline low-risk adenoma group (n = 1869), the 5-year risk of metachronous advanced neoplasia was 4.9% in the younger patients on screening colonoscopy and 5.1% in the older patients (P > .1). Similarly, in the baseline no neoplasia group (n = 7013), the 5-year risk of metachronous advanced neoplasia was 4.1% in the younger patients on screening colonoscopy and 5.6% in the older patients (P > .1). CONCLUSIONS: Considering the similar risk of metachronous advanced neoplasia in younger and older individuals, we suggest a 3-year surveillance interval for high-risk adenoma and a 5-year surveillance interval for low-risk adenoma in young individuals without a strong family history.

An Adjusted Level of Adenoma Detection Rate is Necessary for Adults Below 50 Years Old.

BACKGROUND: Although adenoma prevalence is lower in younger people compared with screening-aged adults 50 years old and above, there is no adjustment recommendation for the target adenoma detection rate (ADR) in young people. Herein, we estimated a different target ADR for adults below 50 years old based on screening colonoscopy findings. MATERIALS AND METHODS: Asymptomatic, average-risk adults below 50 years old who underwent screening colonoscopy were enrolled at 12 endoscopy centers in Korea between February 2006 and March 2012. Screening colonoscopies were stratified into low or high ADR groups with ADR levels of 20% and 25%, respectively. RESULTS: The ADRs from 12 endoscopy centers ranged from 12.1% to 43.8% (median ADR, 24.1%) based on 5272 young adults receiving screening colonoscopies. Using 20% as an ADR level, the risks for metachronous adenoma and advanced adenoma were significantly higher in the low ADR group than the high ADR group (35.4% vs. 25.7%, P<0.001; 8.3% vs. 3.7%, P=0.001, respectively). However, using ADR level of 25%, the risk for metachronous neoplasia was similar in the high and low ADR groups in young adults according to screening colonoscopy. In subgroup analysis, similar findings were found in males, but not in females. CONCLUSIONS: Optimal target ADR may be different between younger and older populations, and the adoption of a 20% target ADR could be used as a performance indicator for young populations.

Prevalence and risk factors for upper gastrointestinal diseases in health check-up subjects: a nationwide multicenter study in Korea.

OBJECTIVES: The prevalence of upper gastrointestinal disease is expected to change following advances in socioeconomic status and improved hygiene in Korea. The aim of this study was to investigate the recent trends in upper gastrointestinal diseases based on endoscopic findings and Helicobacter pylori (H. pylori) seroprevalence in subjects undergoing health check-up at tertiary centers in Korea. METHODS: A multicenter cross-sectional study was conducted at nine healthcare centers between September 2016 and June 2017. The subjects were evaluated using questionnaires, upper endoscopy and H. pylori serology tests. The results were compared with previous data in our study group obtained from eight tertiary healthcare centers in 2011 (n = 4023). RESULTS: In total, we prospectively enrolled 2504 subjects undergoing health check-up. The prevalence of reflux esophagitis (RE) was 9.7%, which showed an increasing but insignificant trend since 2011 (8.8%). The prevalence of active and healing-stage benign gastric ulcer and duodenal ulcer (DU) was 1.6% and 1.2%, respectively, which confirmed a significant decrease since 2011 (4.1%; p < .001 and 2.2%; p = .005, respectively). The prevalence of gastric cancer was 0.5%, representing an increasing trend since 2011 (0.12%; p = .003). H. pylori seroprevalence was 51.3%, which significantly decreased from 2011 (59.8%; p < .001). In multivariate analysis, H. pylori seropositivity was a significant risk factor for DU (p < .001), whereas a significant protective factor against RE (p < .001). CONCLUSIONS: The significant decrease of H. pylori seroprevalence in the past five years altered the incidence of upper gastrointestinal disease.

Lower expression of endogenous intestinal alkaline phosphatase may predict worse prognosis in patients with Crohn's disease.

BACKGROUNDS: Intestinal alkaline phosphatase (IAP) plays important role in gut homeostasis. We aimed to evaluate the expression of endogenous IAP and to assess the clinical course according to the expression of endogenous IAP in patients with Crohn's disease (CD). METHODS: A total of 32 consecutive patients (14 males) with CD were included in the study. We measured the level of endogenous iAP in inflamed and noninflamed colonic mucosa. To verify the inflammation status, we measured the level of mRNA for IL-6, TNF-α, and TLR-4. We monitored the clinical courses of patients during follow-up after acquisition of biopsy specimens. RESULTS: Median age of patients was 22.5 years (range, 15-49). Median CD activity index (CDAI, range) was 93.7 (22.8~ 154.9). There were colonic involvements in all patients and perianal involvement in 43.8% patients. The mRNA levels of IL-6 (p = 0.005) and TLR-4 (p = 0.013) in inflamed mucosa were significantly higher than those in non-inflamed mucosa. However, there was no difference of expression of TNF-α mRNA (p = 0.345). During a 14-month follow-up (range, 9 months-54 months), there were 19 patients with clinical recurrences. There were 9 patients (9/19, 47.4%) with IAP expression ratio (inflamed to non-inflamed) ≤ 1.0 in patients with clinical recurrence while there was one patient (1/13, 7.7%) with IAP ratio ≤ 1.0 in patients without clinical recurrence (p = 0.024). CONCLUSION: Lower expression of IAP in inflamed mucosa compared to non-inflamed mucosa may be associated with clinical recurrence in patients with CD.

Prospero homeobox 1 mediates the progression of gastric cancer by inducing tumor cell proliferation and lymphangiogenesis.

BACKGROUND: Prospero homeobox 1 (PROX1) functions as a tumor suppressor gene or an oncogene in various cancer types. However, the distinct function of PROX1 in gastric cancer is unclear. We determined whether PROX1 affected the oncogenic behavior of gastric cancer cells and investigated its prognostic value in patients with gastric cancer. METHODS: A small interfering RNA against PROX1 was used to silence PROX1 expression in gastric cancer cell lines AGS and SNU638. Expression of PROX1 in gastric cancer tissues was investigated by performing immunohistochemistry. Apoptosis, proliferation, angiogenesis, and lymphangiogenesis were determined by performing the TUNEL assay and immunohistochemical staining for Ki-67, CD34, and D2-40. RESULTS: PROX1 knockdown induced apoptosis by activating cleaved caspase-3, caspase-7, caspase-9, and poly(ADP-ribose) polymerase, and by decreasing the expression of anti-apoptotic proteins Bcl-2 and Bcl-xL. PROX1 knockdown also suppressed tumor cell proliferation. In addition, PROX1 knockdown decreased lymphatic endothelial cell invasion and tube formation and the expression of vascular endothelial growth factor (VEGF)-C and -D and cyclooxygenase (COX)-2. However, PROX1 knockdown only decreased umbilical vein endothelial cell invasion, not tube formation. The mean Ki-67 labeling index and lymphatic vessel density value of PROX1-positive tumors were significantly higher than those of PROX1-negative tumors. However, no significant difference was observed between PROX1 expression and apoptotic index or microvessel density. PROX1 expression was significantly associated with age, cell differentiation, lymph node metastasis, cancer stage, and poor survival. CONCLUSIONS: These results indicate that PROX1 mediates the progression of gastric cancer by inducing tumor cell proliferation and lymphangiogenesis.

Risk of advanced colorectal neoplasm in patients with more than 10 adenomas on index colonoscopy: A Korean Association for the Study of Intestinal Diseases (KASID) study.

BACKGROUND AND AIM: The number of patients with >10 adenomas is relatively small, and few studies have investigated the risk of colorectal neoplasm (CRN) in these patients. Thus, we aimed to investigate the risk of developing CRN in patients with >10 adenomas and to compare their risk with that of patients with 3-10 adenomas. METHODS: A retrospective multicenter cohort study that included 214 patients with >10 adenomas on index colonoscopy performed between January 2009 and December 2011, and underwent follow-up colonoscopy until December 2015 was conducted. The risk of developing advanced CRN (cancer or advanced adenoma with a diameter of ≥10 mm or with a villous component, or high-grade dysplasia) was investigated and compared with that in patients with 3-10 adenomas (n = 975). RESULTS: Among the 214 patients with >10 adenomas, the mean age was 62.9 years and the mean number of adenomas on index colonoscopy was 14.2. Overall, 57 patients (26.6%) developed an advanced CRN after a mean of 4.3 years from baseline colonoscopy. The respective 3- and 5-year cumulative risks of advanced CRN were 6.8% (95% confidence interval [CI] 2.9-10.7) and 28.7% (95% CI 20.8-36.5), higher than those in the group with 3-10 adenomas (n = 975, P = 0.001). Having >10 adenomas on index colonoscopy was an independent risk factor for developing advanced CRN (odds ratio 2.25, 95% CI 1.49-3.38). CONCLUSIONS: The risk of developing advanced CRN in patients with >10 adenomas was high and statistically higher than that in patients with 3-10 adenomas. Further prospective studies are needed to investigate whether a more intensive surveillance is needed in this group.

Risks of colorectal advanced neoplasia in young adults versus those of screening colonoscopy in patients aged 50 to 54 years.

BACKGROUND AND AIM: The role of screening or diagnostic colonoscopy to detect advanced neoplasia in young cohorts of age < 50 is unclear. This study compared the risk of colorectal neoplasia in a young age cohort against that in 50-54s screening cohort. METHODS: A multi-center retrospective study was conducted at 14 university hospitals to compare the detection rates of neoplasia and advanced neoplasia in screening or diagnostic colonoscopy in the young cohort of < 50s against those in screening colonoscopy in the 50-54s cohort. RESULTS: Among 10 477 eligible subjects, 9765 subjects were enrolled after excluding 712 subjects. Advanced neoplasia detection rates in the young screening cohort was significantly lower than that in the 50-54s screening cohort (5.9% vs 9.3%, P < 0.001). Compared with 50-54s screening cohort, the risk of advanced neoplasia was significantly reduced by 23%, 53%, and 54% in the 45-49s, 40-44s, and 20-39s screening cohorts, respectively. The detection rates of advanced neoplasia in the young diagnostic cohort was 5.0%, which was much lower than 11.8% in 50-54s screening cohort (P < 0.001). Compared with the 50-54s screening cohort, the risk of advanced neoplasia was significantly reduced by 50%, 66%, and 71% in the 45-49s, 40-44s, and 20-39s diagnostic cohorts, respectively. CONCLUSIONS: Colonoscopy to detect advanced neoplasia in young adults aged < 50 years should be reconsidered as their risk of advanced neoplasia on screening or diagnostic colonoscopy was much lower than those of 50-54s screening cohort; however, colonoscopy screening may be justified for high-risk 45-49s cohorts.

Long-Term Clinical Outcomes of Rectal Neuroendocrine Tumors According to the Pathologic Status After Initial Endoscopic Resection: A KASID Multicenter Study.

OBJECTIVES: With advances in diagnostic endoscopy, the detection of rectal neuroendocrine tumors (NETs) has increased. However, clinical outcomes, especially after endoscopic treatment, are still unclear. The aim of this study was to determine the long-term clinical outcomes of endoscopically resected rectal NETs according to the pathologic status after initial resection. METHODS: In this large, multicenter, retrospective cohort study, we analyzed the medical records of patients who underwent endoscopic resection of rectal NETs and were followed for ≥24 months at 16 university hospitals. The outcomes of interest were local or distant recurrence and metachronous lesions. RESULTS: On the pathologic assessment of 407 patients, the resection margin status was positive in 76 (18.7%) and indeterminate in 72 (17.7%) patients. Patients whose rectal NETs were diagnosed or suspected as NETs before resection showed a much higher complete resection rate than those whose tumors were resected as polyps and then diagnosed (P<0.001). Fourteen patients received salvage treatment at 1.9±2.8 months after initial treatment. During a median follow-up period of 45.0 months, local recurrence occurred in 3 (0.74%) patients, but there was no recurrence in the lymph nodes or distant organs. Metachronous rectal NETs were diagnosed in 3 (0.74%) patients. According to the pathologic status after initial resection, local recurrence and metachronous lesions occurred in 1 (0.4%) and 2 (0.8%) patients, respectively, in the pathologic tumor-free group, whereas they occurred in 2 (1.4%) and 1 (0.7%) patients, respectively, in the indeterminate group. CONCLUSIONS: Considering the long-term prognosis including that for recurrences or metachronous lesions, endoscopic resection is an efficient and a safe modality for the treatment of rectal NETs. This treatment may result in favorable clinical outcomes in patients with tumors of indeterminate pathology, as well as in pathologic tumor-free cases after initial resection.

MicroRNA-375 Functions as a Tumor-Suppressor Gene in Gastric Cancer by Targeting Recepteur d'Origine Nantais.

Emerging evidence supports a fundamental role for microRNAs (miRNA) in regulating cancer metastasis. Recently, microRNA-375 (miR-375) was reported to be downregulated in many types of cancers, including gastric cancer. Increase in the expression of Recepteur d'Origine Nantais (RON), a receptor tyrosine kinase, has been reported in tumors. However, the function of miR-375 and RON expression in gastric cancer metastasis has not been sufficiently studied. In silico analysis identified miR-375 binding sites in the 3'-untranslated regions (3'-UTR) of the RON-encoding gene. Expression of miR-375 resulted in reduced activity of a luciferase reporter containing the 3'-UTR fragments of RON-encoding mRNA, confirming that miR-375 directly targets the 3'-UTR of RON mRNA. Moreover, we found that overexpression of miR-375 inhibited mRNA and protein expression of RON, which was accompanied by the suppression of cell proliferation, migration, and invasion in gastric cancer AGS and MKN-28 cells. Ectopic miR-375 expression also induced G1 cell cycle arrest through a decrease in the expression of cyclin D1, cyclin D3, and in the phosphorylation of retinoblastoma (Rb). Knockdown of RON by RNAi, similar to miR-375 overexpression, suppressed tumorigenic properties and induced G1 arrest through a decrease in the expression of cyclin D1, cyclin D3, and in the phosphorylation of Rb. Thus, our study provides evidence that miR-375 acts as a suppressor of metastasis in gastric cancer by targeting RON, and might represent a new potential therapeutic target for gastric cancer.

SOX4 expression is associated with treatment failure and chemoradioresistance in oral squamous cell carcinoma.

BACKGROUND: In humans, sex-determining region-Y (SRY) related high-mobility-group box 4 (SOX4) is linked to development and tumorigenesis. SOX4 is over-expressed in several cancers and has prognostic significance. This study evaluated whether SOX4 affects oncogenic behavior and chemoradiotherapy response in head and neck squamous cell carcinoma (HNSCC) cells, and documented the relationship between its expression and prognosis in oral squamous cell carcinoma (OSCC). METHODS: We used small interfering RNA in HNSCC cells to evaluate the effect of SOX4 on cell proliferation, apoptosis, chemoradiation-induced apoptosis, invasion, and migration. SOX4 expression in OSCC tissues was investigated by immunohistochemistry. RESULTS: SOX4 knockdown (KO) decreased cell proliferation and induced apoptosis by activating caspases-3 and -7, and poly-ADP ribose polymerase and suppressing X-linked inhibitor of apoptosis protein in HNSCC cells; it also enhanced radiation/cisplatin-induced apoptosis; and suppressed tumor cell invasion and migration. Immunostaining showed SOX4 protein was significantly increased in OSCC tissues compared with adjacent normal mucosa. SOX4 expression was observed in 51.8 % of 85 OSCC tissues, and was significantly correlated with treatment failure (P = 0.032) and shorter overall survival (P = 0.036) in patients with OSCC. CONCLUSIONS: SOX4 may contribute to oncogenic phenotypes of HNSCC cells by promoting cell survival and causing chemoradioresistance. It could be a potential prognostic marker for OSCC.

Piperine inhibits IL-1ß-induced IL-6 expression by suppressing p38 MAPK and STAT3 activation in gastric cancer cells.

Piperine, a kind of natural alkaloid found in peppers, has been reported to exhibit anti-oxidative and anti-tumor activities, both in vitro and in vivo. Interleukin-6 (IL-6) is an important cytokine that activates the signal transduction, promotes tumor cell metastasis, and induces malignancy, including in gastric cancer. However, the effects of piperine on IL-6 expression in gastric cancer cells have not yet been well defined. In this study, we investigated the effects of piperine on the IL-6 expression, and examined the underlying signaling pathways via RT-PCR, promoter studies and Western blotting in human gastric cancer TMK-1 cells. Our results showed that piperine inhibited interleukin-1ß (IL-1ß)-induced IL-6 expression in a dose-dependent manner. In addition, piperine also inhibited IL-6 promoter activity. Experiments with mitogen-activated protein kinase (MAPK) inhibitors and dominant negative mutant p38 MAPK indicated that p38 MAPK was essential for IL-6 expression in the TMK-1 cells. Additionally, signal transducer and activator of transcription 3 (STAT3) was also involved in the IL-1ß-induced IL-6 expression in gastric cancer cells. Piperine inhibited IL-1ß-induced p38 MAPK and STAT3 activation and, in turn, blocked the IL-1ß-induced IL-6 expression. Furthermore, gastric cancer cells pretreated with IL-1ß showed markedly enhanced invasiveness, which was partially abrogated by treatment with IL-6 siRNA, piperine, and inhibitors of p38 MAPK and STAT3. These results suggest that piperine may exert at least part of its anti-cancer effect by controlling IL-6 expression through the suppression of p38 MAPK and STAT3.

Livin is associated with the invasive and oncogenic phenotypes of human hepatocellular carcinoma cells.

AIM: Livin, a member of the inhibitors of apoptosis proteins, is expressed in variable cancers, and its expression is considered a poor prognostic marker. The aims of this study were to observe the effect of Livin on the behaviors of hepatocellular carcinoma (HCC) cells and to evaluate its expression in HCC tissues and its relation to prognosis. METHODS: The biological effects of Livin on tumor cell behavior were investigated using siRNA in HepG2 and Chang cells. Migration, invasion and proliferation assays were performed. Flow cytometric analyses and western blotting were used to evaluate the impact of Livin on apoptosis and the cell cycle. In addition, western blotting and immunohistochemistry were used to investigate Livin expression in HCC tissues. RESULTS: Livin knockdown suppressed tumor cell migration, invasion and proliferation in HCC cells, and increased the proportion of apoptotic cells as compared with scrambled siRNA-transfected HCC cells. Furthermore, Livin knockdown resulted in the activation of caspases and increased apoptosis. In addition, Livin knockdown modulated cell cycle regulatory protein levels such as decrease of cyclins and cyclin-dependent kinase (CDK) level, and increase of CDK inhibitor (CDKI) level in HCC cells. The Livin protein level was significantly elevated in HCC tissues as compared with normal hepatic tissues. However, Livin expression was not found to be associated with clinicopathological parameters, which included patient survival. CONCLUSION: These results suggest that Livin is associated with invasive and oncogenic phenotypes of human HCC cells.

Pretreatment antimicrobial susceptibility-guided vs. clarithromycin-based triple therapy for Helicobacter pylori eradication in a region with high rates of multiple drug resistance.

OBJECTIVES: Helicobacter pylori eradication rates with clarithromycin-based triple therapy are declining, and an alternative strategy is needed urgently. We sought to compare the efficacy of pretreatment antimicrobial susceptibility-guided vs. clarithromycin-based triple therapy for H. pylori eradication in a region with high rates of multiple drug resistance. METHODS: Consecutive H. pylori-infected patients with gastric epithelial neoplasms were randomized to receive antimicrobial susceptibility-guided therapy or clarithromycin-based triple therapy for 7 days. In patients in whom the infection was not eradicated, antibiotics were given according to an initial antimicrobial susceptibility test as a second-line therapy in both groups. Eradication rates, antibiotics resistance rates, and drug compliance owing to adverse effects were compared between the groups. RESULTS: In total, 114 patients were enrolled, and 112 completed the protocols. Drug compliance and side effects were similar between the groups. The intention-to-treat eradication rates were 94.7% (95% confidence interval (CI)=88.8-100%, 54/57) in the antimicrobial susceptibility-guided group and 71.9% (95% CI=60.2-83.5%, 41/57) in the clarithromycin-based triple therapy group after the initial treatment (P=0.002), whereas the per-protocol (PP) eradication rates were 96.4% (95% CI=91.5-100%, 54/56) in the antimicrobial susceptibility-guided group and 73.2% (95% CI=61.5-84.8%, 41/56) in the clarithromycin-based triple therapy group (P=0.001). In H. pylori with clarithromycin resistance, the eradication failure rate with first-line treatment was lower in the susceptibility-guided therapy group (0%, 0/12) compared with the clarithromycin-based triple therapy group (80.0%, 95% CI=59.7-100%, 12/15) by PP analysis (P<0.001). CONCLUSIONS: Pretreatment antimicrobial susceptibility-guided therapy is more effective than clarithromycin-based triple therapy for H. pylori eradication in a region with high rates of multiple drug resistance.

Prevalence and risk factors of functional dyspepsia: a nationwide multicenter prospective study in Korea.

GOALS: To evaluate the prevalence of functional dyspepsia (FD) and its risk factors. BACKGROUND: FD is a common disorder, but its negative influences greatly affect the quality of life. The predictive factors of FD are still ambiguous. STUDY: A total of 3399 participants underwent screening gastroscopy at one of 7 nationwide health care centers in Korea and who completed a questionnaire. Atrophic gastritis was defined by gastroscopy. Serologic Helicobacter pylori immunoglobulin G antibody was measured by enzyme-linked immunosorbent assay. RESULTS: Of the 3399 participants who did not have organic diseases, 694 (20.4%) had dyspeptic symptoms such as epigastric pain/soreness or postprandial discomfort. Among the 694 participants, atrophic gastritis and positive H. pylori serology were found in 282 (40.6%) and 422 (60.8%), respectively; these proportions were not different from the remaining asymptomatic subjects. Multivariate analysis showed that having relatives with gastric cancer [odds ratio (OR), 1.35; 95% confidence interval (CI), 1.01-1.81], education below college (OR, 1.32; 95% CI, 1.06-1.64), and high-salt diet (OR, 1.33; 95% CI, 1.05-1.68) were associated with FD symptoms. CONCLUSIONS: FD symptoms were frequently found in the health check-up subjects. Relatives of gastric cancer, education below college, and high-salt diet were risk factors of FD, suggesting that FD is a multifactorial disease.