Stereodivergent synthesis of 2-oxo-oligopyrrolidines by an iterative coupling strategy.

Natural linear polyamines play diverse roles in physiological processes by interacting with receptors at the cellular level. Herein, we describe the stereodivergent synthesis of oligopyrrolidines, which are conformationally constrained polyamines. We synthesized dimeric and trimeric 2-oxo-oligopyrrolidines using an iterative coupling strategy. The key to our success is an iridium-catalyzed trans/cis-selective nucleophilic addition and subsequent threo/erythro-stereoselective reduction. The synthesized pyrrolidines show varying cytotoxicities against a human cancer cell line depending on the number of rings and their stereochemistry.

Percutaneous tracheostomy in the surgical management of oral malignancy: an emerging standard of care.

Percutaneous tracheostomy insertion is commonly performed in the critical care setting. However, its applicability and safety in head and neck (H&N) surgery remains uncertain. This study aimed to compare complications and postoperative recovery for percutaneous tracheostomy versus surgical tracheostomy in H&N surgery. A total of 66 patients undergoing percutaneous tracheostomy as part of H&N microvascular surgery were identified retrospectively. A control cohort of 70 consecutive surgical tracheostomy cases performed by another surgical team in the same department was similarly determined. Generally, the complication rates in the percutaneous and surgical tracheostomy groups were similar, with overall rates being 42% and 31%, respectively. The percutaneous group experienced a higher rate of airway obstruction (15%), primarily due to tube displacement. Time to decannulation and duration of inpatient stay were similar in both groups. Notably, an analysis of tracheostomy tube displacement identified high body mass index (BMI) and bilateral neck dissection as potential risk factors, and all cases occurred on postoperative day one. To mitigate this risk we recommend implementation of a percutaneous tracheostomy management protocol, precise tube selection using preoperative imaging, and careful passage of the stoma intraoperatively. In conclusion, this study found that the percutaneous technique exhibited a similar complication profile. It remains unclear whether the rates of longer-term complications, such as delayed stoma healing and tracheal stenosis, differ between techniques. A future prospective study with appropriate elimination of selection and reporting bias would help address this and similar pertinent issues, including patients' perspectives.

Enfortumab Vedotin-induced Hyperglycemia and Ileal Conduit Reconstruction-induced Metabolic Acidosis.

We report a 76-year-old man who was treated for hyperglycemia and metabolic acidosis after chemotherapy with enfortumab vedotin and pembrolizumab administered after his surgery for bladder cancer. He had an approximately 20-year history of diabetes. His body mass index was 18.6, and he received metformin 1000 mg/day, sitagliptin 50 mg/day, mitiglinide 30 mg/day, and voglibose 0.6 mg/day with hemoglobin A1c was approximately 7%. He underwent total cystectomy and ileal conduit reconstruction. After relapse, he received chemotherapy but later developed hyperglycemia and metabolic acidosis. His hyperglycemia was caused by enfortumab vedotin, and metabolic acidosis was attributable to the ileocecal canal. These symptoms should be remembered as important complications of this standard treatment, which prompted this case report.

Discovery of lipid profiles in plasma-derived extracellular vesicles as biomarkers for breast cancer diagnosis.

Lipids are a major component of extracellular vesicles; however, their significance in tumorigenesis and progression has not been well elucidated. As we previously found that lipid profiles drastically changed in breast tumors upon progression, we hypothesized that lipid profiles of plasma-derived extracellular vesicles could be utilized as breast cancer biomarkers. Here, we adopted modified sucrose cushion ultracentrifugation to isolate plasma-derived extracellular vesicles from breast cancer (n = 105), benign (n = 11), and healthy individuals (n = 43) in two independent cohorts (n = 126 and n = 33) and conducted targeted lipidomic analysis. We established a breast cancer diagnostic model comprising three lipids that showed favorable performance with the area under the receiver operating characteristic curve of 0.759, 0.743, and 0.804 in the training, internal validation, and external test sets, respectively. Moreover, we identified several lipids that could effectively discriminate breast cancer progression and subtypes: phosphatidylethanolamines and phosphatidylserines were relatively higher in Stage III, whereas phosphatidylcholines and sphingomyelins were higher in Stage IV; phosphatidylcholines and ceramides were correspondingly concentrated in HER2-positive patients, while lysophosphatidylcholines and polyunsaturated triglycerides were concentrated in the triple-negative breast cancer subtype. Lipid profiling of plasma-derived extracellular vesicles is a non-invasive and promising approach for diagnosing, staging, and subtyping breast cancer.

Presence of bicontinuous microemulsion-type domains and dielectrically inert interfacial water layers in lamellar gel-stabilized oil-in-water emulsions.

HYPOTHESIS: Lamellar gels are widely formulated in household and cosmetic products because of their eminent ability to improve long-term stability of thermodynamically unstable oil-in-water emulsions. However, despite long study, how and why membrane internal structure and membrane-membrane interactions are modified by the presence of polar and nonpolar oils remains elusive. EXPERIMENTS: Using small- and wide-angle X-ray scattering, dielectric spectroscopy, and field-emission transmission electron microscope, we investigate intermembrane interactions and water-mediated microscopic interfacial properties in lamellar gels and lamellar gel-stabilized oil-in-water emulsions based on cetyltrimethylammonium chloride and 1-hexadecanol. FINDINGS: Reducing membrane surface charge density enhances undulation fluctuation disorder, resulting in a crossover of dominant interactions from electrostatic double-layer repulsion to Helfrich interaction. Oil-emulsification induces similar structural impacts to the reduced 1-hexadecanol ratio, confirming preferential dissolution of higher-alcohol in oil phases. An emerging Teubner-Stray scattering component upon emulsification of nonpolar oil evidences that oil droplets and lamellar gels are indirectly connected via bicontinuous microemulsion-type domains. Dielectric spectra reveal strikingly small water permittivity in the lamellar gel and emulsion samples, which is quantitatively explained by a cumulative effect of a dielectrically inert interfacial thin water layer (<1nm) and a highly polarizable bulk-like water layer. This phenomenon appears to be intrinsic to diverse lamellar stack architectures.

Hierarchical Elemental Odor Coding for Fine Discrimination Between Enantiomer Odors or Cancer-Characteristic Odors.

Odors trigger various emotional responses such as fear of predator odors, aversion to disease or cancer odors, attraction to male/female odors, and appetitive behavior to delicious food odors. Odor information processing for fine odor discrimination, however, has remained difficult to address. The olfaction and color vision share common features that G protein-coupled receptors are the remote sensors. As different orange colors can be discriminated by distinct intensity ratios of elemental colors, such as yellow and red, odors are likely perceived as multiple elemental odors hierarchically that the intensities of elemental odors are in order of dominance. For example, in a mixture of rose and fox-unique predator odors, robust rose odor alleviates the fear of mice to predator odors. Moreover, although occult blood odor is stronger than bladder cancer-characteristic odor in urine samples, sniffer mice can discriminate bladder cancer odor in occult blood-positive urine samples. In forced-choice odor discrimination tasks for pairs of enantiomers or pairs of body odors vs. cancer-induced body odor disorders, sniffer mice discriminated against learned olfactory cues in a wide range of concentrations, where correct choice rates decreased in the Fechner's law, as perceptual ambiguity increased. In this mini-review, we summarize the current knowledge of how the olfactory system encodes and hierarchically decodes multiple elemental odors to control odor-driven behaviors.

ELOVL2 promotes cancer progression by inhibiting cell apoptosis in renal cell carcinoma.

Renal cell carcinoma (RCC) is an aggressive genitourinary malignancy which has been associated with a poor prognosis, particularly in patients with metastasis, its major subtypes being clear cell RCC (ccRCC), papillary PCC (pRCC) and chromophobe RCC (chRCC). The presence of intracellular lipid droplets (LDs) is considered to be a hallmark of ccRCC. The importance of an altered lipid metabolism in ccRCC has been widely recognized. The elongation of very­long­chain fatty acid (ELOVL) catalyzes the elongation of fatty acids (FAs), modulating lipid composition, and is required for normal bodily functions. However, the involvement of elongases in RCC remains unclear. In the present study, the expression of ELOVL2 in ccRCC was examined; in particular, high levels of seven ELOVL isozymes were observed in primary tumors. Of note, elevated ELOVL2 expression levels were observed in ccRCC, as well as in pRCC and chRCC. Furthermore, a higher level of ELOVL2 was significantly associated with the increased incidence of a poor prognosis of patients with ccRCC and pRCC. The CRISPR/Cas9­mediated knockdown of ELOVL2 resulted in the suppression of the elongation of long­chain polyunsaturated FAs and increased LD production in renal cancer cells. Moreover, ELOVL2 ablation resulted in the suppression of cellular proliferation via the induction of apoptosis in vitro and the attenuation of tumor growth in vivo. On the whole, the present study provides new insight into the tumor proliferation mechanisms involving lipid metabolism, and suggests that ELOVL2 may be an attractive novel target for RCC therapy.

Impact of prior cerebrovascular disease and glucose status on incident cerebrovascular disease in Japanese.

BACKGROUND: Although both a history of cerebrovascular disease (CVD) and glucose abnormality are risk factors for CVD, few large studies have examined their association with subsequent CVD in the same cohort. Thus, we compared the impact of prior CVD, glucose status, and their combinations on subsequent CVD using real-world data. METHODS: This is a retrospective cohort study including 363,627 men aged 18-72 years followed for ≥ 3 years between 2008 and 2016. Participants were classified as normoglycemia, borderline glycemia, or diabetes defined by fasting plasma glucose, HbA1c, and antidiabetic drug prescription. Prior and subsequent CVD (i.e. ischemic stroke, transient ischemic attack, and non-traumatic intracerebral hemorrhage) were identified according to claims using ICD-10 codes, medical procedures, and questionnaires. RESULTS: Participants' mean age was 46.1 ± 9.3, and median follow up was 5.2 (4.2, 6.7) years. Cox regression analysis showed that prior CVD + conferred excess risk for CVD regardless of glucose status (normoglycemia: hazard ratio (HR), 8.77; 95% CI 6.96-11.05; borderline glycemia: HR, 7.40, 95% CI 5.97-9.17; diabetes: HR, 5.73, 95% CI 4.52-7.25). Compared with normoglycemia, borderline glycemia did not influence risk of CVD, whereas diabetes affected subsequent CVD in those with CVD- (HR, 1.50, 95% CI 1.34-1.68). In CVD-/diabetes, age, current smoking, systolic blood pressure, high-density lipoprotein cholesterol, and HbA1c were associated with risk of CVD, but only systolic blood pressure was related to CVD risk in CVD + /diabetes. CONCLUSIONS: Prior CVD had a greater impact on the risk of CVD than glucose tolerance and glycemic control. In participants with diabetes and prior CVD, systolic blood pressure was a stronger risk factor than HbA1c. Individualized treatment strategies should consider glucose tolerance status and prior CVD.

Identification and Enzymatic Analysis of an Archaeal ATP-Dependent Serine Kinase from the Hyperthermophilic Archaeon Staphylothermus marinus.

Serine kinase catalyzes the phosphorylation of free serine (Ser) to produce O-phosphoserine (Sep). An ADP-dependent Ser kinase in the hyperthermophilic archaeon Thermococcus kodakarensis (Tk-SerK) is involved in cysteine (Cys) biosynthesis and most likely Ser assimilation. An ATP-dependent Ser kinase in the mesophilic bacterium Staphylococcus aureus is involved in siderophore biosynthesis. Although proteins displaying various degrees of similarity with Tk-SerK are distributed in a wide range of organisms, it is unclear if they are actually Ser kinases. Here, we examined proteins from Desulfurococcales species in Crenarchaeota that display moderate similarity with Tk-SerK from Euryarchaeota (42 to 45% identical). Tk-serK homologs from Staphylothermus marinus (Smar_0555), Desulfurococcus amylolyticus (DKAM_0858), and Desulfurococcus mucosus (Desmu_0904) were expressed in Escherichia coli. All three partially purified recombinant proteins exhibited Ser kinase activity utilizing ATP rather than ADP as a phosphate donor. Purified Smar_0555 protein displayed activity for l-Ser but not other compounds, including d-Ser, l-threonine, and l-homoserine. The enzyme utilized ATP, UTP, GTP, CTP, and the inorganic polyphosphates triphosphate and tetraphosphate as phosphate donors. Kinetic analysis indicated that the Smar_0555 protein preferred nucleoside 5'-triphosphates over triphosphate as a phosphate donor. Transcript levels and Ser kinase activity in S. marinus cells grown with or without serine suggested that the Smar_0555 gene is constitutively expressed. The genes encoding Ser kinases examined here form an operon with genes most likely responsible for the conversion between Sep and 3-phosphoglycerate of central sugar metabolism, suggesting that the ATP-dependent Ser kinases from Desulfurococcales play a role in the assimilation of Ser. IMPORTANCE Homologs of the ADP-dependent Ser kinase from the archaeon Thermococcus kodakarensis (Tk-SerK) include representatives from all three domains of life. The results of this study show that even homologs from the archaeal order Desulfurococcales, which are the most structurally related to the ADP-dependent Ser kinases from the Thermococcales, are Ser kinases that utilize ATP, and in at least some cases inorganic polyphosphates, as the phosphate donor. The differences in properties between the Desulfurococcales and Thermococcales enzymes raise the possibility that Tk-SerK homologs constitute a group of kinases that phosphorylate free serine with a wide range of phosphate donors.

Molecular classification and diagnostics of upper urinary tract urothelial carcinoma.

Upper urinary tract urothelial carcinoma (UTUC) is one of the common urothelial cancers. Its molecular pathogenesis, however, is poorly understood, with no useful biomarkers available for accurate diagnosis and molecular classification. Through an integrated genetic study involving 199 UTUC samples, we delineate the landscape of genetic alterations in UTUC enabling genetic/molecular classification. According to the mutational status of TP53, MDM2, RAS, and FGFR3, UTUC is classified into five subtypes having discrete profiles of gene expression, tumor location/histology, and clinical outcome, which is largely recapitulated in an independent UTUC cohort. Sequencing of urine sediment-derived DNA has a high diagnostic value for UTUC with 82.2% sensitivity and 100% specificity. These results provide a solid basis for better diagnosis and management of UTUC.

Identification of madangamine A as a novel lysosomotropic agent to inhibit autophagy.

Madangamines are marine natural products isolated from Xestospongia ingens, and madangamine A-E with a different D-ring structure have been reported. We have reported that madangamine A has strong anti-proliferative activity against various human cancer cell lines. In this study, to clarify the anti-proliferative activity of madangamine A, we searched for molecular target of the madangamine A in human cells. Treatment with madangamine A increased the levels of LC3-II and p62, autophagy-related proteins, concomitant with growth inhibition. Moreover, madangamine A resulted in lysosome enlargement and increase in lysosomal pH, which are same phenomena observed in chloroquine-treated cells. These results suggest that madangamine A is a novel lysosome inhibitor, and the anti-proliferative activity of madangamine A is due to the inhibition of lysosome function.

The liposome of trehalose dimycolate extracted from M. bovis BCG induces antitumor immunity via the activation of dendritic cells and CD8+ T cells.

Intravesical Bovis bacillus Calmette-Guérin (BCG) therapy is the most effective immunotherapy for bladder cancer, but it sometime causes serious side effects because of its inclusion of live bacteria. It is necessary to develop a more active but less toxic immunotherapeutic agent. Trehalose 6,6'-dimycolate (TDM), the most abundant hydrophobic glycolipid of the BCG cell wall, has been reported to show various immunostimulatory activities such as granulomagenesis and adjuvant activity. Here, we developed cationic liposomes incorporating TDM purified from Mycobacterium bovis BCG Connaught, and we investigated the antitumor effect of the cationic liposome TDM (Lip-TDM). Lip-TDM exerted an antitumor effect in bladder cancer, colon cancer, and melanoma-bearing mouse models that was comparable or even superior to that of BCG, with no body weight loss or granuloma formation. The antitumor effect of Lip-TDM disappeared in two types of mice: those with depletion of CD8+ T cells, and those with knockout of macrophage-inducible C-type lectin (Mincle) which recognize TDM. Lip-TDM treatment enhanced the maturation and migration of dendritic cells in the tumor microenvironment in a Mincle-dependent manner. Our results elucidate mechanisms that underlie Lip-TDM treatment and suggest that Lip-TDM has potential as a safe and effective treatment for various cancers.

Seven-Step Synthesis of All-Nitrogenated Sugar Derivatives Using Sequential Overman Rearrangements.

All-nitrogenated sugars (ANSs), in which all hydroxy groups in a carbohydrate are replaced with amino groups, are anticipated to be privileged structures with useful biological activities. However, ANS synthesis has been challenging due to the difficulty in the installation of multi-amino groups. We report herein the development of a concise synthetic route to peracetylated ANSs in seven steps from commercially available monosaccharides. The key to success is the use of the sequential Overman rearrangement, which enables formal simultaneous substitution of four or five hydroxy groups in monosaccharides with amino groups. A variety of ANSs are available through the same reaction sequence starting from different initial monosaccharides by chirality transfer of secondary alcohols. Transformations of the resulting peracetylated ANSs such as glycosylation and deacetylation are also demonstrated. Biological studies reveal that ANS-modified cholesterol show cytotoxicity against human cancer cell lines, whereas each ANS and cholesterol have no cytotoxicity.

Case Report: Molecular Characterization of Aggressive Malignant Retroperitoneal Solitary Fibrous Tumor: A Case Study.

Solitary fibrous tumors (SFT) are mesenchymal neoplasms with a favorable prognosis usually originating from the visceral pleura. Rarely, they may occur at various extrapleural sites and show malignant behavior coupled with dedifferentiation. NAB2-STAT6 fusion gene and STAT6 nuclear expression are biomarkers for diagnosis of SFT in addition to CD34, Bcl-2, and CD99. Furthermore, several reports have shown specific NAB2-STAT6 fusion variants and loss of STAT6 protein expression are associated with malignancy. We report a rare case of retroperitoneal SFT which rapidly progressed to death within 35 days after admission. Autopsy found a primary tumor containing both benign and malignant histologies, with multiple metastatic sites similar to the malignant, dedifferentiated tumor. STAT6 was detected in the primary differentiated tumor but not in the primary dedifferentiated tumor or lung/liver metastases. However, the NAB2-STAT6 fusion gene (NAB2ex6/STAT6ex16 variant) was detected in the primary tumor and lung/liver metastases. Intriguingly, fusion gene expression at the transcriptional level was downregulated in the dedifferentiated tumors compared to the differentiated tumor. We further performed target DNA sequencing and found gene mutations in TP53, FLT3, and AR in the dedifferentiated tumors, with TP53 mutations especially found among them. We demonstrate that downregulation of NAB2-STAT6 fusion gene at the transcriptional level is associated with malignant SFT for the first time. Moreover, the present study supports the idea that TP53 mutations promote malignancy in SFTs.

Network Meta-Analysis of Drug Therapies for Lowering Uric Acid and Mortality Risk in Patients with Heart Failure.

PURPOSE: This network meta-analysis aimed to assess the current efficacy of decreasing the uric acid (UA) level with drugs to reduce mortality in patients with heart failure (HF). METHODS: Electronic literature searches using EMBASE and MEDLINE of studies published from 1 Jan 1950 to 26 Dec 2019 were conducted for randomized controlled trials or non-randomized cohort studies that included at least one group of patients who took UA-lowering drugs and with a study outcome of all-cause mortality. A random-effects network meta-analysis was performed within a frequentist framework. Hierarchy of treatments was expressed as the surface under the cumulative ranking curve (SUCRA) value, which is in proportion to mean rank (best is 100%). RESULTS: Nine studies, which included seven different types of groups, were eligible for analysis. The "untreated uricemia" group in which patients had hyperuricemia but without treatment had a significantly higher risk of mortality than the "no uricemia" group in which patients had no hyperuricemia (relative risk (RR)(95% confidence interval (CI), 1.43 (1.08-1.89)). The "start-allo" group wherein patients started to take allopurinol did not have a significantly lower risk of mortality than the "untreated uricemia" group (RR (95% CI), 0.68 (0.45-1.01)). However, in the "start-allo" group the SUCRA value was comparable to that in the "no uricemia" group (SUCRA: 65.4% for "start-allo"; 64.1% for "no uricemia"). CONCLUSIONS: Results suggested that allopurinol therapy was not associated with a significantly improved prognosis in terms of mortality but could potentially counteract the adverse effects associated with longstanding hyperuricemia in HF patients.

The Inhibitor of Apoptosis Protein Livin Confers Resistance to Fas-Mediated Immune Cytotoxicity in Refractory Lymphoma.

Death receptor Fas-mediated apoptosis not only eliminates nonspecific and autoreactive B cells but also plays a major role in antitumor immunity. However, the possible mechanisms underlying impairment of Fas-mediated induction of apoptosis during lymphomagenesis remain unknown. In this study, we employed our developed syngeneic lymphoma model to demonstrate that downregulation of Fas is required for both lymphoma development and lymphoma cell survival to evade immune cytotoxicity. CD40 signal activation significantly restored Fas expression and thereby induced apoptosis after Fas ligand treatment in both mouse and human lymphoma cells. Nevertheless, certain human lymphoma cell lines were found to be resistant to Fas-mediated apoptosis, with Livin (melanoma inhibitor of apoptosis protein; ML-IAP) identified as a driver of such resistance. High expression of Livin and low expression of Fas were associated with poor prognosis in patients with aggressive non-Hodgkin's lymphoma. Livin expression was tightly driven by bromodomain and extraterminal (BET) proteins BRD4 and BRD2, suggesting that Livin expression is epigenetically regulated in refractory lymphoma cells to protect them from Fas-mediated apoptosis. Accordingly, the combination of CD40-mediated Fas restoration with targeting of the BET proteins-Livin axis may serve as a promising immunotherapeutic strategy for refractory B-cell lymphoma. SIGNIFICANCE: These findings yield insights into identifying risk factors in refractory lymphoma and provide a promising therapy for tumors resistant to Fas-mediated antitumor immunity. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/20/4439/F1.large.jpg.

Combined Cohesin-RUNX1 Deficiency Synergistically Perturbs Chromatin Looping and Causes Myelodysplastic Syndromes.

STAG2 encodes a cohesin component and is frequently mutated in myeloid neoplasms, showing highly significant comutation patterns with other drivers, including RUNX1. However, the molecular basis of cohesin-mutated leukemogenesis remains poorly understood. Here we show a critical role of an interplay between STAG2 and RUNX1 in the regulation of enhancer-promoter looping and transcription in hematopoiesis. Combined loss of STAG2 and RUNX1, which colocalize at enhancer-rich, CTCF-deficient sites, synergistically attenuates enhancer-promoter loops, particularly at sites enriched for RNA polymerase II and Mediator, and deregulates gene expression, leading to myeloid-skewed expansion of hematopoietic stem/progenitor cells (HSPC) and myelodysplastic syndromes (MDS) in mice. Attenuated enhancer-promoter loops in STAG2/RUNX1-deficient cells are associated with downregulation of genes with high basal transcriptional pausing, which are important for regulation of HSPCs. Downregulation of high-pausing genes is also confirmed in STAG2-cohesin-mutated primary leukemia samples. Our results highlight a unique STAG2-RUNX1 interplay in gene regulation and provide insights into cohesin-mutated leukemogenesis. SIGNIFICANCE: We demonstrate a critical role of an interplay between STAG2 and a master transcription factor of hematopoiesis, RUNX1, in MDS development, and further reveal their contribution to regulation of high-order chromatin structures, particularly enhancer-promoter looping, and the link between transcriptional pausing and selective gene dysregulation caused by cohesin deficiency.This article is highlighted in the In This Issue feature, p. 747.

Simultaneous activities in both mirror-image glomerular maps in the olfactory bulb may have an important role in stress-related neuronal responses in mice.

In the mouse olfactory bulb (OB), odor input from the olfactory epithelium innervates topographically to form odorant maps, which are mirror-image arrangements of glomerular clusters with domain organization. However, the functional role of the mirror-image representation in the OB remains unknown. Predator odors induce stress responses, and the dorsal domain of the dorsolateral wall of the olfactory bulb (dlOB) is known to be involved in this process. However, it remains unclear whether the activities in the medial wall of the OB (mOB), the other mirror half, are also involved in stress responses. Therefore, in this study, we investigated whether the mOB and dlOB are required for the induction of stress responses using lesioning or electrical stimulation. Although there were no significant differences in the number of activated neurons in the bed nucleus of the stria terminalis, posterior piriform cortex or amygdalo-piriform transition area, fewer activated neurons were observed in the anterior piriform cortex (APC) following lesion of both the mOB and dlOB combined. No changes were observed in the density of activated cells in any examined brain region following stimulation of either the mOB or dlOB alone. However, activated neurons in the APC were significantly more numerous following simultaneous stimulation of the mOB and dlOB. Collectively, our results suggest that simultaneous activation in both the mOB and dlOB is needed to induce APC neural activities that produce stress-like behavior. These findings provide insight into olfactory information processing, and may also help in the development of therapies for odor-induced stress behaviors.

Frequent mutations that converge on the NFKBIZ pathway in ulcerative colitis.

Chronic inflammation is accompanied by recurring cycles of tissue destruction and repair and is associated with an increased risk of cancer1-3. However, how such cycles affect the clonal composition of tissues, particularly in terms of cancer development, remains unknown. Here we show that in patients with ulcerative colitis, the inflamed intestine undergoes widespread remodelling by pervasive clones, many of which are positively selected by acquiring mutations that commonly involve the NFKBIZ, TRAF3IP2, ZC3H12A, PIGR and HNRNPF genes and are implicated in the downregulation of IL-17 and other pro-inflammatory signals. Mutational profiles vary substantially between colitis-associated cancer and non-dysplastic tissues in ulcerative colitis, which indicates that there are distinct mechanisms of positive selection in both tissues. In particular, mutations in NFKBIZ are highly prevalent in the epithelium of patients with ulcerative colitis but rarely found in both sporadic and colitis-associated cancer, indicating that NFKBIZ-mutant cells are selected against during colorectal carcinogenesis. In further support of this negative selection, we found that tumour formation was significantly attenuated in Nfkbiz-mutant mice and cell competition was compromised by disruption of NFKBIZ in human colorectal cancer cells. Our results highlight common and discrete mechanisms of clonal selection in inflammatory tissues, which reveal unexpected cancer vulnerabilities that could potentially be exploited for therapeutics in colorectal cancer.

Extracellular vesicles mediate the horizontal transfer of an active LINE-1 retrotransposon.

Long interspersed element-1 (LINE-1 or L1) retrotransposons replicate through a copy-and-paste mechanism using an RNA intermediate. However, little is known about the physical transmission of retrotransposon RNA between cells. To examine the horizontal transfer of an active human L1 retrotransposon mediated by extracellular vesicles (EVs), human cancer cells were transfected with an expression construct containing a retrotransposition-competent human L1 tagged with a reporter gene. Using this model, active retrotransposition events were detected by screening for the expression of the reporter gene inserted into the host genome by retrotransposition. EVs including exosomes and microvesicles were isolated from cells by differential centrifugation. The enrichment of L1-derived reporter RNA transcripts were detected in EVs isolated from cells expressing active L1 retrotransposition. The delivery of reporter RNA was confirmed in recipient cells, and reporter genes were detected in the genome of recipient cells. Additionally, employing qRT-PCR, we found that host-encoded factors are activated in response to increased exposure to L1-derived RNA transcripts in recipient cells. Our results suggest that the horizontal transfer of retrotransposons can occur through the incorporation of RNA intermediates delivered via EVs and may have important implications for the intercellular regulation of gene expression and gene function.