Gemcitabine is a nucleoside analog widely used as an anticancer agent against several types of cancer. Although gemcitabine sometimes shows excellent effectiveness, cancer cells are often poorly responsive to or resistant to the drug. Recently, specific strains or dysbiosis of the human microbiome were correlated with drug reactivity and resistance acquisition. Therefore, we aimed to identify antibiotic compounds that can modulate the microbiome to enhance the responsiveness to gemcitabine. To achieve this, we confirmed the gemcitabine responsiveness based on public data and conducted drug screening on a set of 250 antibiotics compounds. Subsequently, we performed experiments to investigate whether the selected compounds could enhance the responsiveness to gemcitabine. First, we grouped a total of seven tumor cell lines into resistant and sensitive group based on the IC50 value (1 μM) of gemcitabine obtained from the public data. Second, we performed high-throughput screening with compound treatments, identifying seven compounds from the resistant group and five from the sensitive group based on dose dependency. Finally, the combination of the selected compound, puromycin dihydrochloride, with gemcitabine in gemcitabine-resistant cell lines resulted in extensive cell death and a significant increase in cytotoxic efficacy. Additionally, mRNA levels associated with cell viability and stemness were reduced. Through this study, we screened antibiotics to further improve the efficacy of existing anticancer drugs and overcome resistance. By combining existing anticancer agents and antibiotic substances, we hope to establish various drug combination therapies and ultimately improve cancer treatment efficacy.
The heat shock protein ClpB in Escherichia coli is a protein-activated ATPase and consists of two proteins with sizes of 93 and 79 kDa. By polymerase chain reaction-aided site-directed mutagenesis, both the proteins have been shown to be encoded by the same reading frame of the clpB gene, the 93-kDa protein (ClpB93) from the 5'-end AUG translational initiation site and the 79-kDa protein (ClpB79) from the 149th codon (an internal GUG start site). Both the purified ClpB93 and ClpB79 proteins behave as tetrameric complexes with a very similar size of about 350 kDa upon gel filtration on a Superose-6 column. Both appear to be exclusively localized to the cytosol of E. coli. Both show inherent ATPase activities and have an identical Km of 1.1 mM for ATP. The ATPase activity of ClpB93 is as markedly stimulated by proteins, including casein and insulin, as that of wild-type ClpB, but the same proteins show little or no effect on ClpB79. Because ClpB79 lacks the 148 N-terminal sequence of ClpB93 but retains the two consensus sequences for adenine nucleotide binding, the N-terminal portion appears to contain a site(s) or domain(s) responsible for protein binding. Furthermore, ClpB79 is capable of inhibiting the casein-activated ATPase activity of ClpB93 in a dose-dependent manner but without any effect on its inherent ATPase activity. In addition, ClpB93 mixed with differing amounts of ClpB79 behave as tetrameric molecules, although its protein-activated ATPase activity is gradually reduced. These results suggest that tetramer formation between ClpB93 and ClpB79 may be responsible for the inhibition of the activity.
Secondary systemic (AA) amyloidosis is a severe complication of progressed Crohn disease (CD) characterized by the deposition of amyloid A in body organs and tissues. Various therapeutic approaches have been recommended, however there is still no effective treatment. Recently, several case reports have demonstrated the effects of anti-tumor necrosis factor-α therapy in patients with AA amyloidosis associated with CD. We report on a 35-year-old female patient with CD complicated by AA amyloidosis in the gastrointestinal tract and renal involvement, who was treated with infliximab. The infliximab therapy improved the gastrointestinal symptoms and decreased the serum creatinine.
Abstract Background and Aim We aimed to assess the gene expression profiles of nonlesional small bowels in patients with Crohn's disease (CD) to identify its accompanying molecular alterations. Methods We performed RNA sequencing of the uninflamed small bowel tissues obtained from 70 patients with ileal CD and 9 patients with colon cancer (non‐CD controls) during bowel resection. Differentially expressed gene (DEG) analyses were performed using DESeq2. Gene set enrichment, correlation, and cell deconvolution analyses were applied to identify modules and functionally enriched transcriptional signatures of CD. Results A comparison of CD patients and non‐CD controls revealed that of the 372 DEGs, 49 protein‐coding genes and 5 long non‐coding RNAs overlapped with the inflammatory bowel disease susceptibility loci. The pathways related to immune and inflammatory reactions were upregulated in CD, while metabolic pathways were downregulated in CD. Compared with non‐CD controls, CD patients had significantly higher proportions of immune cells, including plasma cells ( P = 1.15 × 10 −4 ), and a lower proportion of epithelial cells ( P = 1.12 × 10 −4 ). Co‐upregulated genes (M14 module) and co‐downregulated genes (M9 module) were identified in CD patients. The M14 module was enriched in immune‐related genes and significantly associated with the responses to anti‐tumor necrosis factor (TNF) therapy. The core signature of the M14 module was comprised of six genes and was upregulated in nonresponders to anti‐TNF therapy of five independent cohorts ( n = 163), indicating acceptable discrimination ability (area under the receiver operating characteristic curve of 75–86%). Conclusions The differences in gene expression and cellular composition between CD patients and non‐CD controls imply significant molecular alterations, which are associated with the response to anti‐TNF treatment.
An aerobic, pale-orange-pigmented, Gram-stain-negative bacterium, designated strain EM39T, was isolated from seawater from the eastern coast of Jeju Island, Korea, and its taxonomic status was established using a polyphasic approach. Comparative 16S rRNA gene sequence studies revealed that strain EM39T formed a distinct lineage within the family Flavobacteriaceae and could be distinguished from strains of members of the related genera Gaetbulibacter, Mariniflexile and Tamlana by 16S rRNA gene sequence analysis (similarity values between strain EM39T and related strains were all less than 93.8 %). Cells of strain EM39T were non-gliding, catalase- and oxidase-positive rods that were devoid of flexirubin pigments. Growth was observed at 15–35 °C (optimum, 25–30 °C) and pH 6.5–9.0 (optimum, pH 7.0–8.5). The genomic DNA G+C content was 34.6 mol% and the major respiratory quinone was MK-6. The predominant cellular fatty acids were iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH. On the basis of phenotypic and genotypic data, strain EM39T represents a novel species in a new genus in the family Flavobacteriaceae, for which the name Jejuia pallidilutea gen. nov., sp. nov. is proposed. The type strain is EM39T (=KCTC 22298T=DSM 21165T).
Crohn's disease (CD) and ulcerative colitis (UC), two major subtypes of inflammatory bowel disease, show substantial differences in their clinical course and treatment response. To identify the genetic factors underlying the distinct characteristics of these two diseases, we performed a genome-wide association study (GWAS) between CD (n = 2359) and UC (n = 2175) in a Korean population, followed by replication in an independent sample of 772 CD and 619 UC cases. Two novel loci were identified with divergent effects on CD and UC: rs9842650 in CD200 and rs885026 in NCOR2. In addition, the seven established susceptibility loci [major histocompatibility complex (MHC), TNFSF15, OTUD3, USP12, IL23R, FCHSD2 and RIPK2] reached genome-wide significance. Of the nine loci, six (MHC, TNFSF15, OTUD3, USP12, IL23R and CD200) were replicated in the case-case GWAS of European populations. The proportion of variance explained in CD-UC status by polygenic risk score analysis was up to 22.6%. The area under the receiver-operating characteristic curve value was 0.74, suggesting acceptable discrimination between CD and UC. This CD-UC GWAS provides new insights into genetic differences between the two diseases with similar symptoms and might be useful in improving their diagnosis and treatment.
Tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) is a potential biological anticancer agent. However, a wide range of human primary cancers, including pancreatic cancer, display resistance to apoptosis induction by TRAIL. Therefore, this resistance needs to be overcome to allow TRAIL to be successfully used in cancer therapy. In this study, we performed a compound screen to isolate TRAIL sensitizers and found that one of the identified compounds, 7‐benzylidenenaltrexone maleate (BNTX), sensitized pancreatic cancer cells to TRAIL‐induced apoptotic cell death. The combination of BNTX with TRAIL promoted the release of cytochrome c from mitochondria into cytosol with caspase activation and a resulting increase in annexin‐V‐stained cells. From a mechanistic perspective, we found that BNTX downregulated X‐linked inhibitor of apoptosis protein (XIAP) expression when used in combination with TRAIL and BNTX and that TRAIL‐induced apoptosis was augmented by the siRNA‐mediated knockdown of XIAP with caspase activation. We further demonstrated that BNTX promoted the ubiquitin/proteasome‐dependent degradation of XIAP protein via protein kinase C (PKC) alpha/AKT pathway inhibition. Moreover, combined treatment by BNTX with TRAIL suppressed tumor growth in vivo . Therefore, we suggest that inhibitor of apoptosis protein‐mediated resistance of pancreatic cancer cells to anticancer therapeutics can be overcome by inhibiting the PKCα/AKT pathway. Support or Funding Information This work was supported (40%) by (1) the Basic Science Research Program (NRF‐2016R1D1A1B03932365) funded by the Ministry of Science, Information & Communication Technology (ICT) and Future Planning, and (2) supported (30%) by a grant of the Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (Grant Number: HI14C2640), and (3) supported by a Center for Women in Science, Engineering and Technology (WISET) grant (20%) funded by the Ministry of Science, ICT & Future Planning of Korea (MSIP) under the Program for Returners into R&D (KW‐2015‐PPD‐0134), and (4) supported by internal research program of ASAN Institute for Life Sciences (10%) (16‐512 & 16‐586).
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