S100P Expression via DNA Hypomethylation Promotes Cell Growth in the Sessile Serrated Adenoma/Polyp-Cancer Sequence.

BACKGROUND/AIMS: Sessile serrated adenomas/polyps (SSA/Ps) are a putative precursor lesion of colon cancer. Although the relevance of DNA hypermethylation in the SSA/P-cancer sequence is well documented, the role of DNA hypomethylation is unknown. We investigated the biological relevance of DNA hypomethylation in the SSA/P-cancer sequence by using 3-dimensional organoids of SSA/P. METHODS: We first analyzed hypomethylated genes using datasets from our previous DNA methylation array analysis on 7 SSA/P and 2 cancer in SSA/P specimens. Expression levels of hypomethylated genes in SSA/P specimens were determined by RT-PCR and immunohistochemistry. We established 3-dimensional SSA/P organoids and performed knockdown experiments using a lentiviral shRNA vector. DNA hypomethylation at CpG sites of the gene was quantitated by MassARRAY analysis. RESULTS: The mean number of hypomethylated genes in SSA/P and cancer in SSA/P was 41.6 ± 27.5 and 214 ± 19.8, respectively, showing a stepwise increment in hypomethylation during the SSA/P-cancer sequence. S100P, S100α2, PKP3, and MUC2 were most commonly hypomethylated in SSA/P specimens. The mRNA and protein expression levels of S100P, S100α2, and MUC2 were significantly elevated in SSA/P compared with normal colon tissues, as revealed by RT-PCR and immunohistochemistry, respectively. Among these, mRNA and protein levels were highest for S100P. Knockdown of the S100P gene using a lentiviral shRNA vector in 3-dimensional SSA/P organoids inhibited cell growth by >50% (p < 0.01). The mean diameter of SSA/P organoids with S100P gene knockdown was significantly smaller compared with control organoids. MassARRAY analysis of DNA hypomethylation in the S100P gene revealed significant hypomethylation at specific CpG sites in intron 1, exon 1, and the 5'-flanking promoter region. CONCLUSION: These results suggest that DNA hypomethylation, including S100P hypomethylation, is supposedly associated with the SSA/P-cancer sequence. S100P overexpression via DNA hypomethylation plays an important role in promoting cell growth in the SSA/P-cancer sequence.

JMJD2A sensitizes gastric cancer to chemotherapy by cooperating with CCDC8.

BACKGROUND: Jumonji domain-containing protein 2A (JMJD2A) of the JMJD2 family of histone lysine demethylases has been implicated in tumorigenesis. However, its expression and role in gastric cancer (GC) drug resistance remain unknown. Here, we investigated the role of JMJD2A in GC chemotherapeutic susceptibility and its clinical relevance in GC. METHODS: We selected 12 relevant genes from previously identified gene signatures that can predict GC susceptibility to docetaxel, cisplatin, and S-1 (DCS) therapy. Each gene was knocked down using siRNA in GC cell lines, and cell viability assays were performed. JMJD2A expression in GC cell lines and tissues was assessed using qRT-PCR and immunohistochemistry, respectively. A JMJD2A downstream target related to drug susceptibility was examined using whole-gene expression array and immunoprecipitation. RESULTS: Among the 12 candidate genes, down-regulation of JMJD2A showed the maximum effect on GC susceptibility to anti-cancer drugs and increased the IC50 values for 5-FU, cisplatin, and docetaxel 15.3-, 2.7-, and 4.0-fold, respectively. JMJD2A was universally expressed in 12 GC cell lines, and its overexpression in GC tissue was positively correlated with tumor regression in 34 DCS-treated patients. A whole-gene expression array of JMJD2A-knockdown GC cells demonstrated a significant decrease in the expression of pro-apoptotic coiled-coil domain containing 8 (CCDC8), a downstream target of JMJD2A. Direct interaction between CCDC8 and JMJD2A was verified using immunoprecipitation. CCDC8 inhibition restored drug resistance to docetaxel, cisplatin, and S-1. CONCLUSIONS: Our results indicate that JMJD2A is a novel epigenetic factor affecting GC chemotherapeutic susceptibility, and JMJD2A/CCDC8 is a potential GC therapeutic target.

MicroRNA-296-5p Promotes Cell Invasion and Drug Resistance by Targeting Bcl2-Related Ovarian Killer, Leading to a Poor Prognosis in Pancreatic Cancer.

BACKGROUND/AIMS: Pancreatic ductal adenocarcinoma (PDAC) is characterized by aggressive invasion, early metastasis, and resistance to chemotherapy, leading to a poor prognosis. To clarify the molecular mechanism of these malignant characteristics, we performed a genome-wide microRNA (miRNA) array analysis utilizing micro-cancer tissues from patients with unresectable PDAC (stage IV), obtained by endoscopic ultrasound-fine needle aspiration (EUS-FNA). METHODS: The expression profiles of 2,042 miRNAs were determined using micro-cancer tissues from 13 patients with unresectable PDAC obtained by EUS-FNA. The relationship between individual miRNA levels and overall survival (OS) was analyzed. Possible target genes for miRNAs were bioinformatically analyzed using the online database miRDB. Pancreatic cancer cell lines PANC-1, MIA PaCa-2, and PK-8 were transfected with miRNA mimic or small interfering RNA, and cell invasion, epithelial-mesenchymal transition (EMT), and apoptosis markers were examined. miRNA and mRNA expressions were examined by quantitative polymerase chain reaction. RESULTS: Of 2,042 miRNAs, the 10 that exhibited the lowest correlation coefficient (p ≤ 0.005) between miRNA expression level and OS among the patients were identified. The miRDB and expression analysis in cancer cell lines for the 10 miRNAs identified miR-296-5p and miR-1207-5p as biomarkers predictive of shorter survival (p < 0.0005). Bioinformative target gene analysis and transfection experiments with miRNA mimics showed that Bcl2-related ovarian killer (BOK), a pro-apoptotic gene, is a target for miR296-5p in pancreatic cancer cells; transfection of miR-296-5p mimic into PANC-1, MIA PaCa-2, and PK-8 cells resulted in significant suppression of BOK mRNA and protein expression. These transfectants showed significantly higher invasion capability compared with control cells, and knock down of BOK in pancreatic cancer cells similarly enhanced invasion capability. Transfectants of miR-296-5p mimic also exhibited aberrant expression of EMT markers, including vimentin and N-cadherin. Moreover, these transfectants showed a significantly lower apoptosis rate in response to 5-fluorouracil and gemcitabine with a decrease of BOK expression, suggesting a role of miR-296-5p in drug resistance. CONCLUSION: These results suggest that miR-296-5p is a useful biomarker for a poor prognosis in patients with PDAC, and that the miR-296-5p/BOK signaling axis plays an important role in cell invasion, drug resistance, and EMT in PDACs.

Inhibitory Effects of Sodium Alginate on Hepatic Steatosis in Mice Induced by a Methionine- and Choline-deficient Diet.

Nonalcoholic steatohepatitis (NASH) progresses from nonalcoholic fatty liver disease (NAFLD); however, efficacious drugs for NASH treatment are lacking. Sodium alginate (SA), a soluble dietary fiber extracted from brown algae, could protect the small intestine from enterobacterial invasion. NASH pathogenesis has been suggested to be associated with enterobacterial invasion, so we examined the effect of SA on methionine- and choline-deficient (MCD) diet-induced steatohepatitis in mice (the most widely-used model of NASH). The mice (n = 31) were divided into three groups (mice fed with regular chow, MCD diet, and MCD diet premixed with 5% SA) for 4 and 8 weeks. The MCD diet increased lipid accumulation and inflammation in the liver, the NAFLD Activity Score and hepatic mRNA expression of tumor necrosis factor- and collagen 11, and induced macrophage infiltration. Villus shortening, disruption of zonula occludens-1 localization and depletion of mucus production were observed in the small intestine of the MCD-group mice. SA administration improved lipid accumulation and inflammation in the liver, and impaired barrier function in the small intestine. Collectively, these results suggest that SA is useful for NASH treatment because it can prevent hepatic inflammation and fatty degeneration by maintaining intestinal barrier function.

CD44v-dependent upregulation of xCT is involved in the acquisition of cisplatin-resistance in human lung cancer A549 cells.

Cisplatin (CDDP) is widely used as an anti-cancer platinum agent but its therapeutic efficacy is limited by acquired drug resistance. To develop a new therapeutic strategy that could overcome this resistance, it is important to characterize CDDP-resistant cancer cells. Here we established human lung cancer A549 cell-derived low- and high-grade CDDP-resistant sublines, termed ACR4 and ACR20 cells, by stepwise increasing CDDP concentrations up to 4 and 20 µM, respectively. ACR4 and ACR20 cells showed 6- and 16-fold higher resistance to CDDP than A549 cells, respectively. Cell migration, invasion, and sphere formation were significantly decreased, whereas expression of the stem cell marker CD44v was increased in order of A549, ACR4, and ACR20 cells. The expression of the cystine-glutamate transporter xCT, which is encoded by SLC7A11, was upregulated because of the increased cell surface expression of CD44v in ACR20 cells. Treatment with the xCT inhibitor salazosulfapyridine and knockdown of SLC7A11 mRNA by a specific siRNA significantly improved sensitivity to CDDP in A549, ACR4, and ACR20 cells. Thus, our results suggest that CD44v overexpression is not involved in cancer stem cell properties but increases xCT expression, which leads to the acquisition of CDDP-resistance. This mechanism may contribute to the development of a new therapeutic strategy that can overcome resistance.

Mechanism of recipient cell-dependent differences in exosome uptake.

BACKGROUND: Exosomes, small-membrane vesicles, are secreted by cells and include several types of proteins and nucleic acids. Exosomes transfer cellular information derived from donor cells and are involved in various physiological and pathological events, such as organ-specific metastasis. Elucidating the exosome uptake mechanisms is important for understanding the progression processes of organ-specific metastasis. However, whether the exosomes secreted by the donor cells are selectively or non-selectively incorporated into the recipient cells is unknown. METHODS: In this study, three human carcinoma cell lines, A549 (lung), HCT116 and COLO205 (colon), were used. The exosome isolation efficiency was compared between three methods: ultracentrifugation, ExoQuick-TC and Total Exosome Isolation kits. Recipient cells were treated with Pitstop 2, an inhibitor of clathrin-dependent endocytosis, or genistein, an inhibitor of caveolae-dependent endocytosis, and then incubated with DiO-labeled exosomes. RESULTS: Among the three methods examined, ultracentrifugation was the most efficient and reproducible. Exosomes derived from a donor cell line are incorporated into the three cell lines, but the exosome uptake capability was different depending on the recipient cell type and did not depend on the donor cell type. Exosome uptake in COLO205 was inhibited by Pitstop 2 and genistein. Exosome uptake in HCT116 was inhibited by Pitstop 2, but not genistein, while that in A549 cells was not inhibited by these inhibitors. Taken together, these results suggest that the exosomes secreted by donor cells are non-selectively incorporated into recipient cells and that the exosome uptake mechanism is different depending on the recipient cells. CONCLUSIONS: Different recipient cells' exosome uptake capabilities may be involved in organ-specific metastasis.

Potential contribution of erythrocyte microRNA to secondary erythrocytosis and thrombocytopenia in congenital heart disease.

BackgroundChildren with cyanotic heart disease develop secondary erythrocytosis and thrombocytopenia via unknown mechanisms. Mature erythrocyte microRNAs may reflect clinical pathologies and cell differentiation processes pre-enucleation. This study evaluated erythrocyte microRNAs in children with cyanotic heart disease.MethodsErythrocyte microRNAs from children with cyanotic and acyanotic heart disease and without cardiac disease were quantified with Ion PGM System (n=10 per group). Differential expression was confirmed by quantitative PCR (qPCR; n=20 per group).ResultsMir-486-3p, mir-486-5p, and mir-155-5p increased in patients with cyanotic heart disease compared with those without heart disease: fold differences (95% confidence interval): mir-486-3p: 1.92 (1.14-3.23), P=0.011; mir-486-5p: 2.27 (1.41-3.65), P<0.001; and mir-155-5p: 1.44 (1.03-2.03), P=0.028. Mir-486-5p was increased, and let-7e-5p and mir-1260a were decreased in patients with acyanotic heart disease compared with those without heart disease: mir-486-5p: 1.66 (1.03-2.66), P=0.035; let-7e-5p: 0.66 (0.44-0.99), P=0.049; and mir-1260a: 0.53 (0.29-0.99), P=0.045.ConclusionSeveral microRNA levels changed in children with cyanotic and acyanotic heart disease. Mir-486-3p and -5p are associated with hematopoietic differentiation. Mir-486-3p regulates the erythroid vs. megakaryocyte lineage fate decision. Mir-155 is a hypoxia-inducible microRNA, whose overexpression inhibits megakaryocyte differentiation. Erythrocyte microRNA expression changes may contribute to erythrocytosis and thrombocytopenia in children with cyanotic heart disease.

Response Predictors of S-1, Cisplatin, and Docetaxel Combination Chemotherapy for Metastatic Gastric Cancer: Microarray Analysis of Whole Human Genes.

OBJECTIVES: The aim of this study was to identify biomarkers for predicting the efficacy of docetaxel, cisplatin, and S-1 (DCS) therapy for advanced gastric cancer using microarrays of biopsy specimens before chemotherapy. METHODS: Nineteen samples were taken from 19 patients with unresectable metastatic gastric cancer who received DCS as a first-line therapy. Laser capture microdissection was performed, and total cellular RNA was extracted from each microdissected sample. Whole-gene expression was analyzed by microarray, and the difference in mRNA expression observed with the microarrays was confirmed by quantitative real-time PCR. Immunohistochemical staining was performed using clinical tissue sections obtained by endoscopic biopsy. RESULTS: Eleven patients were identified as early responders and 8 patients as nonresponders to DCS therapy. Twenty-nine genes showed significant differences in relative expression ratios between tumor and normal tissues. A classifier set of 29 genes had high accuracy (94.7%) for distinguishing gene expression between 11 early responders and 8 nonresponders. Decreasing the size of the classifier set to 4 genes (PDGFB, PCGF3, CISH, and ANXA5) increased the accuracy to 100%. Expression levels by real-time PCR for validation were well correlated with those 4 genes in microarrays. CONCLUSION: The genes identified may serve as efficient biomarkers for personalized cancer-targeted therapy.

Indigo Naturalis Ameliorates Oxazolone-Induced Dermatitis but Aggravates Colitis by Changing the Composition of Gut Microflora.

BACKGROUND: Indigo naturalis (IND) is an herbal medicine that has been used as an anti-inflammatory agent to treat diseases including dermatitis and inflammatory bowel disease in China. However, the mechanism by which IND exerts its immunomodulatory effect is not well understood. METHODS: A murine model of dermatitis and inflammatory bowel disease, both induced by oxazolone (OXA), was treated with IND. The severity of dermatitis was evaluated based on ear thickness measurements and histological scoring. The severity of colitis was evaluated by measuring body weight, histological scoring, and endoscopic scoring. The expression of inflammatory cytokines in ear and colon tissue was evaluated using real-time PCR. 16S rRNA DNA sequencing of feces from OXA-induced colitis mice was performed before and after IND treatment. The effects of IND on OXA-induced colitis were also evaluated after depleting the gut flora with antibiotics to test whether alteration of the gut flora by IND influenced the course of intestinal inflammation in this model. RESULTS: IND treatment ameliorated OXA dermatitis with a reduction in IL-4 and eosinophil recruitment. However, OXA colitis was significantly aggravated in spite of a reduction in intestinal IL-13, a pivotal cytokine in the induction of the colitis. It was found that IND dramatically altered the gut flora and IND no longer exacerbated colitis when colitis was induced after gut flora depletion. CONCLUSIONS: Our data suggest that IND could modify the inflammatory immune response in multiple ways, either directly (i.e., modification of the allergic immune cell activity) or indirectly (i.e., alteration of commensal compositions).

Clinicopathological Assessment of Gastric Xanthoma as Potential Predictive Marker of Gastric Cancer.

BACKGROUND/AIMS: Gastric xanthomas are frequently observed in the stomach as small yellowish plaques or nodules. A close relationship among Helicobacter pylori infection, atrophic gastritis, and xanthomas has been reported. We assessed the clinicopathological features of gastric cancer with or without xanthomas. METHODS: A total of 91 patients who were diagnosed as having early gastric cancer were enrolled. We evaluated the gastritis status using scores for gastritis and atrophy, positivity of H. pylori infection, the prevalence rate of xanthomas, and the clinicopathological features of gastric cancer. RESULTS: Gastric xanthomas were observed in 72.5% of early gastric cancer cases. Scores for gastritis and atrophy were significantly higher in the xanthoma-positive group than those in the xanthoma-negative group. A higher prevalence of differentiated-type adenocarcinoma was found in the xanthoma-positive group. Among the cases with multiple gastric xanthomas, the prevalence of males was significantly higher than that of females. CONCLUSION: A high prevalence rate of gastric xanthomas in gastric cancer cases was shown. Xanthomas were highly associated with age, the severities of gastritis and atrophy, and differentiated-type adenocarcinoma. Regardless of the eradication of H. pylori, xanthomas may be useful predictive markers for the development of differentiated-type adenocarcinoma.

Variants in KCNQ1 are associated with susceptibility to type 2 diabetes mellitus.

We carried out a multistage genome-wide association study of type 2 diabetes mellitus in Japanese individuals, with a total of 1,612 cases and 1,424 controls and 100,000 SNPs. The most significant association was obtained with SNPs in KCNQ1, and dense mapping within the gene revealed that rs2237892 in intron 15 showed the lowest Pvalue (6.7 x 10(-13), odds ratio (OR) = 1.49). The association of KCNQ1 with type 2 diabetes was replicated in populations of Korean, Chinese and European ancestry as well as in two independent Japanese populations, and meta-analysis with a total of 19,930 individuals (9,569 cases and 10,361 controls) yielded a P value of 1.7 x 10(-42) (OR = 1.40; 95% CI = 1.34-1.47) for rs2237892. Among control subjects, the risk allele of this polymorphism was associated with impairment of insulin secretion according to the homeostasis model assessment of beta-cell function or the corrected insulin response. Our data thus implicate KCNQ1 as a diabetes susceptibility gene in groups of different ancestries.

MicroRNA expression in hepatocellular carcinoma after the eradication of chronic hepatitis virus C infection using interferon therapy.

AIM: Hepatocellular carcinoma (HCC) develops in up to 5% of patients after the successful treatment of chronic hepatitis C virus (HCV) infection using interferon therapy. The aim of this study was to characterize miRNA expression in liver tissues from patients who achieved a sustained viral response (SVR). METHODS: Seventy-one patients with resected HCC were enrolled into the present study: 61 HCC from patients with continuously infected HCV (HCV-HCC) and 10 from patients who had achieved SVR (SVR-HCC). We also included non-tumor tissues (SVR-NT) from four patients with SVR-HCC, and liver tissue (SVR-CH) from four SVR patients without HCC. Total RNA was extracted from liver samples. The miRNA expression patterns were analyzed using microarrays. In addition, target gene expression was quantified after miRNA overexpression in HEK293 cells. RESULTS: We could discriminate between SVR-HCC and HCV-HCC with 75.36% accuracy using the expression pattern of six specific miRNA. The expression levels of 37 miRNA were significantly lower in HCV-HCC than in SVR-HCC, whereas the expression of 25 miRNA was significantly higher in HCV-HCC than SVR-HCC (P < 1.0E-05). The expression of thrombospondin 1 was regulated in an opposing manner by miR-30a-3p in SVR-HCC and HCV-HCC. In non-tumor tissues, the expression pattern of seven miRNA could distinguish between SVR-CH and SVR-NT with 87.50% accuracy. CONCLUSION: Comprehensive miRNA expression analyses could not only differentiate between SVR-HCC and HCV-HCC but also forecast hepatocarcinogenesis after achieving SVR.

Preventative Effects of Sodium Alginate on Indomethacin-induced Small-intestinal Injury in Mice.

Recent advances in diagnostic technologies have revealed that nonsteroidal anti-inflammatory drugs (NSAIDs) can cause serious mucosal injury in the upper and lower gastrointestinal tract (including the small intestine). A drug to treat NSAID-induced small-intestinal injury (SII) is lacking. Sodium alginate is a soluble dietary fiber extracted from brown seaweed and its solution has been used as a hemostatic agent to treat gastrointestinal bleeding due to gastric ulcers. Whether sodium alginate has therapeutic effects on NSAID-induced SII and its mechanism of action are not known. Here, we investigated if administration of two forms (high-molecular-weight (HMW) and low-molecular-weight (LMW)) of sodium alginate could ameliorate indomethacin-induced SII. Pretreatment with HMW sodium alginate or LMW sodium alginate before indomethacin administration improved ulceration and the resultant intestinal shortening was associated with reduced histological severity of mucosal injury and ameliorated mRNA expression of inflammation-related molecules in the small intestine. We found that mRNAs of secretory Muc2 and membrane-associated Muc1, Muc3 and Muc4 were expressed in the small intestine. mRNA expression of Muc1-4 was increased in indomethacin-induced SII, and these increases were prevented by sodium alginate. Thus, administration of sodium alginate could be a therapeutic approach to prevent indomethacin-induced SII.

Down-regulation of hepatic CYP3A1 expression in a rat model of indomethacin-induced small intestinal ulcers.

The liver and the small intestine are closely related in the processes of drug absorption, metabolism and excretion via the enterohepatic circulation. Small intestinal ulcers are a serious adverse effect commonly occurring in patients taking nonsteroidal anti-inflammatory drugs. However, the influence of small intestinal ulcers on drug metabolism has not been established. This study examined the expressional changes of cytochrome P450 (CYP) in the liver using an indomethacin-induced small intestinal ulcer rat model and in cultured cells. After the administration of indomethacin to rats, ulcers were observed in the small intestine and expression of CYP3A1, the major isoform of hepatic CYP, was significantly down-regulated in the liver, accompanied by increased expression of inducible nitric oxide synthase, tumor necrosis factor α, interleukin (IL)-1ß and IL-6, in the small intestine and the liver. The indomethacin-induced small intestinal ulceration, the increase in inflammatory mediators in the small intestine and the liver, and the down-regulation of CYP3A1 expression in the liver were inhibited by co-administration of ampicillin, an antibacterial agent. In the human hepatic HepG2 cell line, IL-1ß, IL-6 and NOC-18, an NO donor, caused down-regulation of CYP3A4, the major isoform of human CYP3A. Thus, this study suggests that after indomethacin treatment small intestinal ulcers cause the down-regulation of CYP3A1 in the rat liver through an increase in ulcer-derived inflammatory mediators. Copyright © 2016 John Wiley & Sons, Ltd.

Discovering novel direct acting antiviral agents for HBV using in silico screening.

The treatments for chronic hepatitis B (CHB) are interferon and nucleoside analogues reverse transcriptase (RT) inhibitors. Because both treatments are less than ideal, we conducted to identify novel anti-viral agents for HBV-reverse transcriptase (HBV-RT). We determined the ligand-binding site of the HBV-RT by conducting a homological search of the amino acid sequence and then we also determined not only structural arrangement of the target protein but the target protein-binding site of the ligand using known protein-ligand complexes in registered in the protein data bank (PDB). Finally we simulated binding between the ligand candidates and the HBV-RT and evaluated the degree of binding (in silico screening). PXB cells derived from human-mouse chimeric mouse liver, infected with HBV were administrated with the candidates, and HBVDNA in the culture medium was monitored by realtime qPCR. Among compounds from the AKosSamples database, twelve candidates that can inhibit RT were also identified, two of which seem to have the potential to control HBV replication in vitro.

Development of novel hepatitis B virus capsid inhibitor using in silico screening.

Antiviral therapy for chronic hepatitis B that uses nucleos(t)ide analogue is considered effective. However, most drugs of this class frequently result in viral relapse after cessation of therapy as well as the emergence of resistance, thereby limiting their clinical use. In order to increase the therapeutic efficiency of chronic hepatitis B treatments, it is important to survey novel (chemical) reagents targeting other stages of the viral replication process. The aim of this study was to identify novel capsid inhibitor candidates using in silico screening. We discovered four such candidates that decreased the levels of HBV DNA and HBsAg in vitro. These four capsid inhibitor candidates did not induce cell toxicity even at high concentrations. Results from docking simulation showed that the candidates bounded with high affinity with the capsid protein hydrophobic binding site. Identifying direct acting HBV core protein inhibitors increases the likelihood that novel medicines can be developed that allows the combination of novel anti-viral drugs and nucleos(t)ide analogue or interferon for HBV treatment.

Ultradeep Sequencing for Detection of Quasispecies Variants in the Major Hydrophilic Region of Hepatitis B Virus in Indonesian Patients.

Quasispecies of hepatitis B virus (HBV) with variations in the major hydrophilic region (MHR) of the HBV surface antigen (HBsAg) can evolve during infection, allowing HBV to evade neutralizing antibodies. These escape variants may contribute to chronic infections. In this study, we looked for MHR variants in HBV quasispecies using ultradeep sequencing and evaluated the relationship between these variants and clinical manifestations in infected patients. We enrolled 30 Indonesian patients with hepatitis B infection (11 with chronic hepatitis and 19 with advanced liver disease). The most common subgenotype/subtype of HBV was B3/adw (97%). The HBsAg titer was lower in patients with advanced liver disease than that in patients with chronic hepatitis. The MHR variants were grouped based on the percentage of the viral population affected: major, ≥20% of the total population; intermediate, 5% to <20%; and minor, 1% to <5%. The rates of MHR variation that were present in the major and intermediate viral population were significantly greater in patients with advanced liver disease than those in chronic patients. The most frequent MHR variants related to immune evasion in the major and intermediate populations were P120Q/T, T123A, P127T, Q129H/R, M133L/T, and G145R. The major population of MHR variants causing impaired of HBsAg secretion (e.g., G119R, Q129R, T140I, and G145R) was detected only in advanced liver disease patients. This is the first study to use ultradeep sequencing for the detection of MHR variants of HBV quasispecies in Indonesian patients. We found that a greater number of MHR variations was related to disease severity and reduced likelihood of HBsAg titer.

Oxidative stress-inducible truncated serine/arginine-rich splicing factor 3 regulates interleukin-8 production in human colon cancer cells.

Serine/arginine-rich splicing factor 3 (SRSF3) is a member of the SR protein family and plays wide-ranging roles in gene expression. The human SRSF3 gene generates two alternative splice transcripts, a major mRNA isoform (SRSF3-FL) encoding functional full-length protein and a premature termination codon (PTC)-containing isoform (SRSF3-PTC). The latter is degraded through nonsense-mediated mRNA decay (NMD). Treatment of a human colon cancer cell line (HCT116) with 100 µM sodium arsenite increased SRSF3-PTC mRNA levels without changing SRSF3-FL mRNA levels. A chemiluminescence-based NMD reporter assay system demonstrated that arsenite treatment inhibited NMD activity and increased SRSF3-PTC mRNA levels in the cytoplasm, facilitating translation of a truncated SRSF3 protein (SRSF3-TR) from SRSF3-PTC mRNA. SRSF3-TR lacked two-thirds of the Arg/Ser-rich (RS) domain whose phosphorylation state is known to be crucial for subcellular distribution. SRSF3-FL was localized in the nucleus, while overexpressed SRSF3-TR was diffusely distributed in the cytoplasm and the nucleus. A part of SRSF3-TR was also associated with stress granules in the cytoplasm. Interestingly, treatment of HCT116 cells with a small interference RNA specifically targeting SRSF3-PTC mRNA significantly attenuated arsenite-stimulated induction of c-JUN protein, its binding activity to the AP-1 binding site (-126 to 120 bp) in the interleukin (IL)-8 gene promoter, and AP-1 promoter activity, resulting in significant reduction of arsenite-stimulated IL-8 production. Our results suggest that SRSF3-TR may function as a positive regulator of oxidative stress-initiated inflammatory responses in colon cancer cells.

A deep-sequencing method detects drug-resistant mutations in the hepatitis B virus in Indonesians.

OBJECTIVE: The long-term administration of a nucleos(t)ide analogue (NA) for the treatment of chronic hepatitis B may encourage the emergence of viral mutations associated with drug resistance. Minor populations of viruses may exist before treatment, but are difficult to detect because of technological limitations. Identifying minor viral quasispecies should be useful in the clinical management of hepatitis B virus (HBV) infection. METHODS: Six treatment-naïve Indonesian patients with chronic HBV infection participated in this study. The polymerase region of the HBV genome, including regions with known drug-resistant mutations, was subjected to capillary sequencing and MiSeq sequencing (Illumina). Mutations were analyzed with Genomics Workbench software version 6.0.1 (CLC bio). RESULTS: The mean mapping reads for the six samples was 745,654, and the mean number of amplified fragments ranged from 17,926 to 25,336 DNA reads. Several known drug-resistant mutations in the reverse transcriptase region were identified in all patients, although the frequencies were low (0.12-1.06%). The proportions of the total number of reads containing mutations I169L/M, S202R, M204I/L or N236S were >1.0%. CONCLUSION: Several known NA-resistant mutations were detected in treatment-naïve patients in Indonesia using deep sequencing. Careful management of such patients is essential to prevent drug-resistant mutations from spreading to other patients.

Downregulation of CYP3A and P-glycoprotein in the secondary inflammatory response of mice with dextran sulfate sodium-induced colitis and its contribution to cyclosporine A blood concentrations.

CYP3A and P-glycoprotein (P-gp) play important roles in drug metabolism and excretion; however, their functions in pathological conditions remain unclear. Hepatobiliary abnormalities have been described in patients with ulcerative colitis, which may affect drug metabolism and excretion in the liver and small intestine. We examined the functions of CYP3A and P-gp in the liver and small intestine of mice with dextran sodium sulfate (DSS)-induced colitis. Up to day 7, inflammatory markers were significantly increased in the livers of DSS-treated mice, accompanied by decreased CYP3A. Additionally hepatobiliary transporters and Pregnane X receptor, which regulates the transcriptional activation of CYP3A, were reduced. Both CYP3A and P-gp were significantly decreased in the upper small intestine of DSS-treated mice on day 7. This was associated with the increased expression of inducible nitric oxide synthase, but not changes in nuclear receptor expression. On day 7 of DSS treatment, the concentrations of cyclosporine A (CsA), a substrate of both CYP3A and P-gp, were significantly higher than controls. These results indicated the existence of a second inflammatory response in the liver and upper small intestine of mice with DSS-induced colitis, and bioavailability of CsA was increased by the dysfunction of CYP3A and P-gp in these organs.