Exosomal miR-1305 in the oncogenic activity of hypoxic multiple myeloma cells: a biomarker for predicting prognosis.

Background: Exosomes have emerged as important mediators of tumor progression, and a prognostic role for serum exosomal miRNAs has been suggested in multiple myeloma (MM). Given the association of hypoxia with tumor aggressiveness, including cancer stem cell-like phenotypes, we explored exosomal miRNAs from MM cells under hypoxic conditions and analyzed their diverse roles both in promoting oncogenic activity and in predicting prognosis. Methods: The human MM cell line, RPMI 8226, was cultured under hypoxic conditions and their exosome production and exosomal miRNA profiles were compared with those of normoxic parental cells. The survival outcome of myeloma patients was compared using serum levels of exosomal miRNAs, and the effects of exosomal miRNAs on the target genes of MM cells and adjacent immune cells were analyzed. Results: Increased expression of stem cell markers and exosome production were observed in hypoxic MM cells. Exosome miRNA analysis identified a higher expression of miR-1305 in exosomes isolated from hypoxic MM cells than in those of normoxic parental cells. The overall survival of patients with high exosomal miR-1305 was poorer than it was in patients with low exosomal miR-1305. In hypoxic MM cells, an increase of exosomal miR-1305 led to a decrease of cellular miR-1305 and increased expression of the miR-1305 target genes, MDM2, IGF1 and FGF2 resulted in the promotion of oncogenic activity of MM. Exosomal miR-1305 was also transferred from MM cells to macrophages, and miR-1305-transferred macrophages showed tumor-promoting, M2-macrophage phenotypes. Conclusions: Exosome-mediated secretion of miR-1305 in MM cells promoted oncogenic activity of hypoxic MM cells and high serum levels of exosomal miR-1305.

Utility of positron emission-computed tomography for predicting pathological response in resectable oesophageal squamous cell carcinoma after neoadjuvant chemoradiation.

OBJECTIVES: For patients with locally advanced oesophageal cancer, improved complete pathological response after neoadjuvant chemoradiation (nCRT) and the detrimental effects on the quality of life related to oesophagectomy have led to the need for a reliable method to select patients who have achieved complete pathological response and do not need surgery. The reliability of 18F-fluorodeoxyglucose positron emission-computed tomography (PET-CT) for predicting the pathological response after nCRT was evaluated. METHODS: Patients with locally advanced oesophageal cancer who were treated with nCRT and oesophagectomy from July 2010 to February 2017 were analysed. On the post-nCRT PET-CT, a complete metabolic response was defined as all tumourous lesions demonstrating maximum standardized uptake value (SUVmax) ≤2.5. To minimize the effect of radiation-induced oesophagitis, complete metabolic response was also defined as no viable lesion distinguishable from the background with diffuse uptake. The sensitivity, specificity, positive predictive value and negative predictive value were analysed for SUVmax, [X]ΔSUVmax and %ΔSUVmax. RESULTS: A total of 158 patients with oesophageal squamous cell carcinoma were analysed. The rate of complete pathological response was 27.8%, and that of complete metabolic response was 7.6%. The sensitivity, specificity, positive predictive value and negative predictive value based on SUVmax ≤2.5 and visual normalization were 95%, 14%, 74% and 50%, respectively. Analysis for [X]ΔSUVmax and %ΔSUVmax using the optimal cut-off values determined by the receiver operating characteristic curves did not show an improved predictive efficacy. CONCLUSIONS: PET-CT is not a reliable tool for predicting pathological response. Patients diagnosed with resectable oesophageal cancer who underwent neoadjuvant therapy should not be exempt from surgery based on PET-CT results.

Clinical features and prognosis of breast cancer with gastric metastasis.

Breast cancer rarely metastasizes to the gastrointestinal tract, including the stomach. Due to the rarity of this metastasis, it is occasionally confused with a primary stomach malignancy. However, discriminating characteristic features with clinical implications may exist. The aim of the current study was to analyze the clinical features and prognosis of breast cancer with gastric metastasis. Between January 1994 and October 2016, 13 patients at Samsung Medical Center (Seoul, Korea) were clinically or pathologically determined to have breast cancer with gastric metastasis. The present study retrospectively collected clinicopathological data from the electronic medical records of these 13 female patients. At breast cancer diagnosis, the median patient age was 45 years. A total of 7 patients (53.8%) presented with invasive lobular carcinoma (ILC) and 6 (46.2%) with invasive ductal carcinoma. Of the 13 patients, 11 were stage I-III at initial breast cancer diagnosis and underwent surgery. Positivity of breast cancer tissue samples for estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) was 92.3, 76.9 and 0%, respectively. Positivity of gastric metastasis lesions, based on immunohistochemistry results, was 81.8, 50 and 0% for ER, PR and HER2, respectively. The stomach was the location of the first metastatic lesion in 6 out of the 11 patients (54.5%) with de novo stage I-III cancer. The median time interval from initial breast cancer diagnosis to stomach metastasis was 77.5 months. The 3-year survival rate was 79.1%, and the estimated mean survival time was 35.1 months. Breast cancer with gastric metastasis is rare, and due to this fact, a thorough pathological review and greater clinical suspicion are required in these cases.

Does guideline non-adherence result in worse clinical outcomes for hormone receptor-positive and HER2-negative metastatic breast cancer in premenopausal women?: result of an institution database from South Korea.

BACKGROUND: In this study, we observe the patterns initial palliative treatment for premenopausal patients with HR-positive/HER2-negative MBC and determine if nonadherence to clinical guidelines are associated with worse clinical outcomes in terms of progression-free survival (PFS) and overall survival (OS) in the South Korean population. METHODS: A retrospective review was performed for premenopausal patients diagnosed with HR-positive/HER2-negative MBC between October 1997 and May 2016 who received palliative systemic treatments at a large tertiary medical center. Survival outcomes were analyzed according to the palliative treatment received prior to disease progression. RESULTS: The review identified a total of 272 premenopausal patients meeting study criteria, whose median age was 39 years. Endocrine therapy was the initial treatment in 137 patients (Group 1) with chemotherapy as initial treatment in 135 patients. In the latter group, chemotherapy was continued in 78 patients (Group 2), whereas chemotherapy was switched to endocrine treatment in 57 patients prior to any disease progression (Group 3). Both PFS and OS were significantly longer for chemotherapy-endocrine therapy (median PFS 18.2 months and OS 85.2 months) than for chemotherapy-alone (median PFS 12.6 months and OS 45.5 months) or endocrine therapy-alone (median PFS 7.0 months and OS 57.3 months) (all p values < 0.01). In multivariate analysis, chemotherapy-endocrine therapy was an independent predictive value for improved PFS and OS (hazard ratio [HR] 0.33, 95% CI 0.20-0.52, p <  0.001; HR 0.38, 95% CI 0.19-0.73, p = 0.004). CONCLUSIONS: In our study population, chemotherapy alone was not objectively inferior to endocrine therapy as the initial palliative treatment. In addition, chemotherapy followed by endocrine therapy was associated with objective higher response rate than endocrine therapy alone. Further studies should explore the relationship between non-adherent treatment patterns and patient outcomes across the largely premenopausal breast cancer populations across Asian countries.

Current status of immune checkpoint inhibitors in treatment of non-small cell lung cancer.

Lung cancer remains a leading cause of cancer mortality worldwide, including in Korea. Systemic therapy including platinum-based chemotherapy and targeted therapy should be provided to patients with stage IV non-small cell lung cancer (NSCLC). Applications of targeted therapy, such as an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) and anaplastic lymphoma kinase (ALK) inhibitors, in patients with NSCLC and an EGFR mutation or ALK gene rearrangement has enabled dramatic improvements in efficacy and tolerability. Despite advances in research and a better understanding of the molecular pathways of NSCLC, few effective therapeutic options are available for most patients with NSCLC without druggable targets, especially for patients with squamous cell NSCLC. Immune checkpoint inhibitors such as anti-cytotoxic T lymphocyte antigen-4 or anti-programmed death-1 (PD-1) or programmed death-ligand 1 (PD-L1) have demonstrated durable response rates across a broad range of solid tumors, including NSCLC, which has revolutionized the treatment of solid tumors. Here, we review the current status and future approaches of immune checkpoint inhibitors that are being investigated for NSCLC with a focus on pembrolizumab, nivolumab, atezolizumab, durvalumab, and ipilimumab.

EGFR Mutation Is Associated with Short Progression-Free Survival in Patients with Stage III Non-squamous Cell Lung Cancer Treated with Concurrent Chemoradiotherapy.

PURPOSE: This study was conducted to evaluate the relationship between epidermal growth factor receptor (EGFR) mutation and clinical outcomes in patients with stage III non-squamous cell lung cancer treated with definitive concurrent chemoradiotherapy (CCRT). MATERIALS AND METHODS: From January 2008 to December 2013, the medical records of 197 patients with stage III non- squamous non-small cell lung cancer treated with definitive CCRT were analyzed to determine progression-free survival (PFS) and overall survival (OS) according to EGFR mutation status. RESULTS: Among 197 eligible patients, 81 patients were EGFR wild type, 36 patients had an EGFR mutation (exon 19 Del, n=18; L858R, n=9, uncommon [G719X, L868, T790M], n=9), and 80 patients had unknown EGFR status. The median age was 59 years (range, 28 to 80 years) and 136 patients (69.0%) were male. The median follow-up duration was 66.5 months (range, 1.9 to 114.5 months). One hundred sixty-four patients (83.2%) experienced disease progression. Median PFS was 8.9 months for the EGFR mutation group, 11.8 months for EGFR wild type, and 10.5 months for the unknown EGFR group (p=0.013 and p=0.042, respectively). The most common site of metastasis in the EGFR mutant group was the brain. However, there was no significant difference in OS among the three groups (34.6 months for EGFR mutant group vs. 31.9 months for EGFR wild type vs. 22.6 months for EGFR unknown group; p=0.792 and p=0.284). A total of 29 patients (80.6%) with EGFR mutation were treated with EGFR tyrosine kinase inhibitor (gefitinib, n=24; erlotinib, n=3; afatinib, n=2) upon progression. CONCLUSION: EGFR mutation is associatedwith short PFS and the brain is the most common site of distant metastasis in patients with stage III non- squamous cell lung cancer treated with CCRT.

Clinical Outcomes of EGFR Exon 20 Insertion Mutations in Advanced Non-small Cell Lung Cancer in Korea.

PURPOSE: Epidermal growth factor receptor (EGFR) exon 20 insertion mutations account for approximately 4% of all EGFR mutations. Given the rarity of this mutation, its clinical outcomes are not fully established. MATERIALS AND METHODS: Between 2009 and 2017, non-small cell lung cancer (NSCLC) patients who showed an exon 20 insertion were retrospectively reviewed for clinical characteristics and outcomes, including responses to chemotherapy (CTx) or targeted therapy. RESULTS: Of 3,539 NSCLC patients who harbored an activating EGFR mutation, 56 (1.6%) had an exon 20 insertion. Of the advanced NSCLC patients, 27 of 1,479 (1.8%) had an exon 20 insertion. The median overall survival was 29.4 months (95% confidence interval 9.3 to 49.6) for 27 advancedNSCLC patients. The 22 patientswho received systemic CTx achieved a 50.0% response rate and a 77.2% disease control rate, with 4.2 months of progressionfree survival. Six patients received EGFR tyrosine kinase inhibitors (TKIs). Three of the four patients that had only an exon 20 insertion showed progressive disease, while one showed stable disease. The othertwo patients had an exon 20 insertion and another EGFR mutation and achieved a partial response. CONCLUSION: The incidence of an exon 20 insertion mutation is rare in Korea and occasionally accompanied by other common EGFR mutations. Although the response to systemic CTx. in these patients is comparable to that of patients with other mutations, the response rate to firstor second-generation EGFR TKIs is quite low. Therefore, the development of a more efficient agent is urgently needed.

Discordance of the PAM50 Intrinsic Subtypes Compared with Immunohistochemistry-Based Surrogate in Breast Cancer Patients: Potential Implication of Genomic Alterations of Discordance.

PURPOSE: We aimed to analyze the discordance between immunohistochemistry (IHC)-based surrogate subtyping and PAM50 intrinsic subtypes and to assess overall survival (OS) according to discordance. MATERIALS AND METHODS: A total of 607 patients were analyzed. Hormone receptor (HR) expression was evaluated by IHC, and human epidermal growth factor receptor 2 (HER2) expression was analyzed by IHC and/or fluorescence in situ hybridization. PAM50 intrinsic subtypes were determined according to 50 cancer genes using the NanoString nCounter Analysis System. We matched concordant tumor as luminal A and HR+/HER2-, luminal B and HR+/HER2+, HR-/HER2+ and HER2-enriched, and triple-negative breast cancer (TNBC) and normal- or basal-like. We used Ion Ampliseq Cancer Panel v2 was used to identify the genomic alteration related with discordance. The Kaplan-Meier method was used to estimate OS. RESULTS: In total, 233 patients (38.4%) were discordant between IHC-based subtype and PAM50 intrinsic subtype. Using targeted sequencing, we detected somatic mutation-related discordant breast cancer including the VHL gene in the HR+/HER2- group (31% in concordant group, 0% in discordant group, p=0.03) and the IDH and RET genes (7% vs. 12%, p=0.02 and 0% vs. 25%, p=0.02, respectively) in the TNBC group. Among the luminal A/B patients with a discordant result had significantly worse OS (median OS, 73.6 months vs. not reached; p < 0.001), and among the patients with HR positivity, the basal-like group as determined by PAM50 showed significantly inferior OS compared to other intrinsic subtypes (5-year OS rate, 92.2% vs. 75.6%; p=0.01). CONCLUSION: A substantial portion of patients showed discrepancy between IHC subtype and PAM50 intrinsic subtype in our study. The survival analysis demonstrated that current IHC-based classification could mislead the treatment and result in poor outcome. Current guidelines for IHC might be updated accordingly.

Serum IL18 is associated with hemophagocytosis and poor survival in extranodal natural killer/T-cell lymphoma.

Extranodal natural killer/T-cell lymphoma (ENKTL) is associated with Epstein-Barr virus (EBV) infection, a common cause of hemophagocytosis. As interleukin-18 (IL18) is related with hemophagocytosis, we measured serum IL18 and IL18-related cytokines of newly diagnosed patients with ENKTL (N = 114) to investigate the role as a biomarker for hemophagocytosis and determine the prognosis of ENKTL. The median value of serum IL18 was 20.5 pg/mL (1.23-2021.81 pg/mL). The high IL18 group (≥20.5 pg/mL) was associated with stage III/IV, the presence of hemophagocytosis and poor treatment outcome. Serum IL18 showed significant positive correlations with TNFα, IFNγ, and IP10. Overall survival was significantly different between the high and low IL18 groups (p < .001), and high serum IL18 was independently prognostic for survival in the multivariate analysis. In conclusion, serum IL18 levels may be associated with the hemophagocytosis and poor survival outcomes in patients with ENKTL.

Continuation of gefitinib beyond progression in patients with EGFR mutation-positive non-small-cell lung cancer: A phase II single-arm trial.

OBJECTIVES: Several studies have demonstrated the promise of continuation of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) beyond progression in patients with EGFR-mutant non-small-cell lung cancer (NSCLC). The aim of the present study is to clarify the efficacy of continuation of gefitinib in patients with NSCLC beyond progression. MATERIALS AND METHODS: A total of 50 patients with EGFR-mutant NSCLC who progressed based on Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria during gefitinib treatment were eligible. The primary endpoint was progression-free survival-2 (PFS2; time from first gefitinib dose to off-gefitinib progression). Secondary endpoints were PFS1 (time from first gefitinib dose to RECIST 1.1 progression); the difference between PFS2 and PFS1 (PFS2-PFS1); overall survival (OS); and safety. Patients received gefitinib 250 mg/d orally until symptomatic progression or at the investigator's discretion. RESULTS: Between January 2016 and March 2017, 50 patients were enrolled in this study. One patient withdrew consent, leaving a total of 49 patients to be evaluated. The median PFS2-PFS1 was 5.1 months (95% CI, 2.5-7.8), and the median PFS2 was 27.7 months (95% CI, 21.6-33.9). Twelve patients (24.4%) continued gefitinib therapy for 14 months (median value, range 7.2-20.3 months) after RECIST 1.1 progression. The median OS was not reached. Patients were classified by the characteristics of progression at the time of enrollment. PFS2-PFS1 was significantly shorter in patients with pleural metastasis or pleural effusion compared with the other types of progression (1.8 months vs. 7.1 months, p-value = 0.005). CONCLUSION: In patients with EGFR-mutant NSCLC who experience progression, it is beneficial to maintain gefitinib treatment with local treatment such as radiotherapy until symptomatic progression. However, in patients with pleural metastasis or effusion, continuation of gefitinib beyond progression should be carefully determined on a case by case basis.

Pemetrexed Monotherapy as Salvage Treatment in Patients with Metastatic Colorectal Cancer Refractory to Standard Chemotherapy: A Phase II Single-arm Prospective Trial.

Background: We designed a single-arm, open-label phase II study to determine the efficacy and toxicity of pemetrexed monotherapy with vitamin supplementation in patients with refractory colorectal cancer (CRC) that failed to respond to standard treatments including 5-fluorouracil, oxaliplatin, and irinotecan with or without biologic agents. Methods: Patients were treated with pemetrexed 500 mg/m2 on day 1 every 3 weeks, with folic acid and vitamin B12 supplementation. Treatment was continued until disease progression or intolerable toxicity. Between June 2016 and October 2016, 24 patients were enrolled in this study. Results: One patient withdrew consent, leaving a total of 23 patients for evaluation. The median age of the patients was 54.0 years (range, 23.0 to 67.0), and the median ECOG performance status was 1 (1-2). The median number of previous systemic chemotherapies was 3 (range, 2 to 5). There was no patient with complete response (CR) or partial response (PR). However, stable disease was observed in 10 patients (43.4%) and maintained more than 6 months in 7 of 10 patients. The median progression-free survival was 1.6 months (95% CI, 1.1-2.0) and the median overall survival was 9.8 months (95% CI, 5.9-13.6). Grade 3 treatment-related adverse events occurred in one patient with elevated liver enzymes and hematologic adverse event of grade 2 anemia was observed in one patient. There were no cases of dose reduction or treatment-related deaths and all toxicities were manageable. Conclusions: Pemetrexed monotherapy showed moderate disease control and acceptable toxicity profile as salvage therapy for refractory CRC.

Characteristics and Outcome of ROS1-Positive Non-Small Cell Lung Cancer Patients in Routine Clinical Practice.

INTRODUCTION: ROS1-rearranged NSCLC is classified as a distinct molecular subset of NSCLC with a therapeutic target. ROS1 rearrangement is most often identified in never-smokers with adenocarcinoma and EGFR and ALK receptor tyrosine kinase gene (ALK) wild type. Treatment with tyrosine kinase inhibitors (TKIs), which target the ROS1 kinase domain, is considered the standard of care. TKIs have been shown to have a robust and durable response. However, information regarding the clinical outcomes of TKI treatment, including brain metastasis, remains limited. METHODS: We identified 103 consecutive cases of ROS1-positive NSCLC by using break-apart fluorescence in situ hybridization (n = 84), next-generation sequencing (n = 23), or both (n = 3). Information regarding fusion breakpoints was available for eight patients. Clinical data, including patient characteristics, incidence of brain metastasis, response to chemotherapy, or to TKIs, were retrospectively analyzed. RESULTS: The median patient age was 56 years, and 58.9% of the patients were female. Most of the patients (75.7%) were never-smokers. Adenocarcinoma was predominant (98.1%), and two cases with pleomorphic carcinoma were identified. Sixty percent of patients had an extrathoracic metastatic lesion, and 22% had an intracranial lesion at the initial presentation or at the time of recurrence. The median time to development of brain metastases was 12.0 months (range 2.1-84.1). The most common fusion partner was CD74 molecule gene (CD74), followed by syndecan 4 gene (SDC4), ezrin gene (EZR), tropomyosin 3 gene (TPM3), TRK-fused gene (TFG), zinc finger CCHC-type containing 8 gene (ZCCHC8), sacrolemma associated protein gene (SLMAP), and myosin VC gene (MYO5C). All of these fusion partners preserved the tyrosine kinase domain of ROS1. The median overall survival time was 52.1 months (95% confidence interval [CI]: 23.6-not reached). In the 90 patients who were treated with pemetrexed-based chemotherapy, the overall response rate and progression-free survival time were 53.3% and 8.0 months (95% CI: 6.4-11.7), respectively. The overall response rate and progression-free survival time were 70.7% and 12.7 months (95% CI: 8.1-21.8), respectively, for the 50 patients treated with TKIs. Brain metastasis was more often observed during TKI treatment (15.5%) than during pemetrexed-based chemotherapy (6.7%). CONCLUSIONS: ROS1-positive NSCLC has distinct clinical characteristics, with an effective and durable response to both TKIs and pemetrexed-based chemotherapies. Regardless, given its novel characteristics and distinct clinical responses to conventional chemotherapies and TKIs, the treatment strategy for ROS1-positive NSCLC remains to be further developed.

A Case of Myeloid Sarcoma of Intestine.

Myeloid sarcoma (MS) is an extramedullary involvement of immature myeloid proliferation. An isolated MS is defined as a myeloblastic tumor when it arises without any concomitant circulating disease. A diagnosis of MS is established using pathologic features including infiltration of myeloblasts and strong myeloperoxidase expression with negative cytokeratin immunohistochemical staining. We report a rare case of colonic MS without any peripheral blood abnormality. If the affected patient were left untreated, the MS could evolve into acute myeloid leukemia (AML) within one year. Several studies recommend the same regimens of chemotherapy as used for circulating AML to treat isolated MS. We focused on the diagnosis of MS in this study. The correct diagnosis of MS is important for adequate treatment. In conclusion, MS should be considered in the differential diagnosis of intestinal tumor.

Highly selective production of succinic acid by metabolically engineered Mannheimia succiniciproducens and its efficient purification.

Succinic acid (SA) is one of the fermentative products of anaerobic metabolism, and an important industrial chemical that has been much studied for its bio-based production. The key to the economically viable bio-based SA production is to develop an SA producer capable of producing SA with high yield and productivity without byproducts. Mannheimia succiniciproducens is a capnophilic rumen bacterium capable of efficiently producing SA. In this study, in silico genome-scale metabolic simulations were performed to identify gene targets to be engineered, and the PALK strain (ΔldhA and Δpta-ackA) was constructed. Fed-batch culture of PALK on glucose and glycerol as carbon sources resulted in the production of 66.14 g/L of SA with the yield and overall productivity of 1.34 mol/mol glucose equivalent and 3.39 g/L/h, respectively. SA production could be further increased to 90.68 g/L with the yield and overall productivity of 1.15 mol/mol glucose equivalent and 3.49 g/L/h, respectively, by utilizing a mixture of magnesium hydroxide and ammonia solution as a pH controlling solution. Furthermore, formation of byproducts was drastically reduced, resulting in almost homo-fermentative SA production. This allowed the recovery and purification of SA to a high purity (99.997%) with a high recovery yield (74.65%) through simple downstream processes composed of decolorization, vacuum distillation, and crystallization. The SA producer and processes developed in this study will allow economical production of SA in an industrial-scale. Biotechnol. Bioeng. 2016;113: 2168-2177. © 2016 Wiley Periodicals, Inc.

Polysaccharide isolated from Triticum aestivum stimulates insulin release from pancreatic cells via the ATP-sensitive K+ channel.

Traditional natural plants have been used throughout the world for their antidiabetic effects. The aim of the present study was to investigate the stimulating activity of a polysaccharide extract derived from T. aestivum sprout (TASP) on insulin secretion in vitro using the RIN-5F pancreatic ß-cell line and rat pancreatic islets. In these experiments, TASP (0.1 to 2 mg/ml) augmented glucose-stimulated insulin secretion in a dose-dependent manner in the presence of a stimulatory glucose concentration (16.7 mM), but not of a basal concentration (1.1 mM). Although TASP failed to enhance the high K+-induced insulin secretion, the insulinotropic effect of TASP was significantly inhibited by diazoxide, an opener of ATP-sensitive K+ channel blocking insulin release. TASP potentiated the insulin secretion induced by other secretagogues, such as IBMX and tolbutamide. Moreover, glucose-derived blood insulin levels were significantly elevated by oral administration of TASP to mice, similarly to antidiabetic drugs. We also demonstrated that TASP significantly increased glucose-induced 45Ca2+ uptake and proinsulin mRNA expression in rat islets. Overall, our results suggest that TASP has a stimulating effect on insulin secretion and production in pancreatic ß-cells via K+ channel closure and calcium influx. These results suggest that TASP may be useful as a candidate for the therapy of diabetes mellitus.

Deoxyschisandrin inhibits H2O2-induced apoptotic cell death in intestinal epithelial cells through nuclear factor-kappaB.

Oxidative stress is a pathogenesis for a typical inflammatory intestinal disease known as ulcerative colitis (UC) characterized by erosion and mucosal ulceration. For the treatment of UC, many kinds of traditional Asian medical plants have been used. Schisandra chinensis fruits (SC) are known to possess anti-ulcer, anti-hepatotoxic and anti-neurotoxic activity. However, its mechanism is still unknown. In the present study, we investigated the cytoprotective effect of deoxyschisandrin, a lignan compound comprised of SC fruits, on H2O2-induced apoptotic cell death in human intestinal epithelial cells (HCT116). In flow cytometry assay using Annexin V and propidium iodide, deoxyschisandrin inhibited H2O2-induced apoptotic cell death. To further evaluate the apoptotic signaling by H2O2, we detected caspase-3 activation using cleavage of pro-caspase-3. Deoxyschisandrin inhibited H2O2-induced caspase-3 activation by blocking cleavage of pro-caspase-3. Furthermore, it has been reported that oxidative stress by H2O2 induces an activation of nuclear factor-kappaB (NF-kappaB). In our results, H2O2 stimulated the degradation of IkappaBalpha, inhibitor of NF-kappaB, in a concentration-dependent manner. On the contrary, deoxyschisandrin inhibited H2O2-stimulated degradation of IkappaBalpha and activation of NF-kappaB by blocking translocation of NF-kappaB to the nucleus. Therefore, we suggest that deoxyschisandrin inhibits H2O2-induced apoptotic cell death.