Isoform balance of the long noncoding RNA NEAT1 is regulated by the RNA-binding protein QKI, governs the glioma transcriptome, and impacts cell migration.

The long noncoding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) is involved in a variety of human cancers. Two overlapping NEAT1 isoforms, NEAT1_1 and NEAT1_2, are produced through mutually exclusive alternative 3' end formation. Previous studies extensively investigated NEAT1 dysregulation in tumors, but often failed to achieve distinct quantification of the two NEAT1 isoforms. Moreover, molecular mechanisms governing the biogenesis of NEAT1 isoforms and the functional impacts of their dysregulation in tumorigenesis remain poorly understood. In this study, we employed an isoform-specific quantification assay and found differential dysregulation of NEAT1 isoforms in patient-derived glioblastoma multiforme (GBM) cells. We further showed usage of the NEAT1 proximal polyadenylation site (PAS) is a critical mechanism that controls glioma NEAT1 isoform production. CRISPR-Cas9-mediated PAS deletion reduced NEAT1_1 and reciprocally increased NEAT1_2, which enhanced nuclear paraspeckle formation in human glioma cells. Moreover, the utilization of the NEAT1 PAS is facilitated by the RNA binding protein Quaking (QKI), which binds to the proximal QKI response elements (QREs). Functionally, we identified transcriptomic changes and altered biological pathways caused by NEAT1 isoform imbalance in glioma cells, including the pathway for the regulation of cell migration. Finally, we demonstrated the forced increase of NEAT1_2 upon NEAT1 PAS deletion is responsible for driving glioma cell migration and promoting the expression of genes implicated in the regulation of cell migration. Together, our studies uncovered a novel mechanism that regulates NEAT1 isoforms and their functional impacts on the glioma transcriptome, which affect pathological pathways of glioma, represented by migration.

Hyperpolarized [5-13C,4,4-2H2,5-15N]-L-glutamine provides a means of annotating in vivo metabolic utilization of glutamine.

Glutamine is consumed by rapidly proliferating cells and can provide the carbon and nitrogen required for growth through various metabolic pathways. However, delineating the metabolic fate of glutamine is challenging to interrogate in vivo. Hyperpolarized magnetic resonance, by providing high transient nuclear magnetic resonance signals, provides an approach to measure fast biochemical processes in vivo. Aminohydrolysis of glutamine at carbon-5 plays an important role in providing nitrogen and carbon for multiple pathways. Here, we provide a synthetic strategy for isotope-enriched forms of glutamine that prolongs glutamine-C5 relaxation times and thereby reveals in vivo reactions involving carbon-5. We investigate multiple enrichment states, finding [5-13C,4,4-2H2,5-15N]-L-glutamine to be optimal for hyperpolarized measurement of glutamine conversion to glutamate in vivo. Leveraging this compound, we explore pancreatic cancer glutamine metabolism in vivo. Taken together, this work provides a means for studying glutamine metabolic flux in vivo and demonstrates on-target effects of metabolic enzyme inhibitors.

First in-human evaluation of [1-13C]pyruvate in D2O for hyperpolarized MRI of the brain: A safety and feasibility study.

PURPOSE: To investigate the safety and value of hyperpolarized (HP) MRI of [1-13C]pyruvate in healthy volunteers using deuterium oxide (D2O) as a solvent. METHODS: Healthy volunteers (n = 5), were injected with HP [1-13C]pyruvate dissolved in D2O and imaged with a metabolite-specific 3D dual-echo dynamic EPI sequence at 3T at one site (Site 1). Volunteers were monitored following the procedure to assess safety. Image characteristics, including SNR, were compared to data acquired in a separate cohort using water as a solvent (n = 5) at another site (Site 2). The apparent spin-lattice relaxation time (T1) of [1-13C]pyruvate was determined both in vitro and in vivo from a mono-exponential fit to the image intensity at each time point of our dynamic data. RESULTS: All volunteers completed the study safely and reported no adverse effects. The use of D2O increased the T1 of [1-13C]pyruvate from 66.5 ± 1.6 s to 92.1 ± 5.1 s in vitro, which resulted in an increase in signal by a factor of 1.46 ± 0.03 at the time of injection (90 s after dissolution). The use of D2O also increased the apparent relaxation time of [1-13C]pyruvate by a factor of 1.4 ± 0.2 in vivo. After adjusting for inter-site SNR differences, the use of D2O was shown to increase image SNR by a factor of 2.6 ± 0.2 in humans. CONCLUSIONS: HP [1-13C]pyruvate in D2O is safe for human imaging and provides an increase in T1 and SNR that may improve image quality.

Risk Factors for Postoperative Complications of Laparoscopic Right Colectomy: A Post Hoc Analysis of RELARC Trial.

BACKGROUND: There is concern regarding the possibility of postoperative complications for laparoscopic right colectomy. OBJECTIVE: To evaluate the risk factors of postoperative complications for patients undergoing laparoscopic right colectomy. DESIGN: This was an observational study. SETTINGS: This was a post-hoc analysis of a prospective, multicenter, randomized controlled trial (RELARC trial, NCT02619942). PATIENTS: Patients included in the modified intention-to-treat analysis in RELARC trial were all enrolled in this study. MAIN OUTCOME MEASURES: Risk factors for postoperative complications were identified using univariate and multivariable logistic regression analysis. RESULTS: Of 995 patients, 206 (20.7%) had postoperative complications. Comorbidity (p = 0.02, OR: 1.544, 95% CI: 1.077-2.212) and operative time >180 min (p = 0.03, OR: 1.453, 95% CI: 1.032-2.044) were independent risk factors for postoperative complications. While female (p = 0.04, OR: 0.704, 95% CI: 0.506-0.980) and extracorporeal anastomosis (p < 0.001, OR: 0.251, 95% CI: 0.166-0.378) were protective factors. Eighty (8.0%) had overall surgical site infection, 53 (5.3%) had incisional SSI, and 33 (3.3%) had organ/space SSI. Side-to-side anastomosis was a risk factor for overall surgical site infection (p < 0.001, OR: 1.912, 95% CI: 1.118-3.268) and organ/space surgical site infection (p = 0.005, OR: 3.579, 95% CI: 1.455-8.805). Extracorporeal anastomosis was associated with a reduced risk of overall surgical site infection (p < 0.001, OR: 0.239, 95% CI: 0.138-0.413), organ/space surgical site infection (p = 0.002 OR: 0.296, 95% CI: 0.136-0.646), and incisional surgical site infection (p < 0.001, OR: 0.179, 95% CI: 0.099-0.322). Diabetes (p = 0.039 OR: 2.090, 95% CI: 1.039-4.205) and conversion to open surgery (p = 0.013 OR: 5.403, 95% CI: 1.437-20.319) were risk factors for incisional surgical site infection. LIMITATIONS: Due to the retrospective nature, the key limitation is the lack of prospective documentation and standardization about perioperative management of these patients such as preoperative optimization, bowel prep regimes and antibiotic regimes, which may be confounder factors of complications. All surgeries were done by experienced surgeons and the patients enrolled were relatively young, generally healthy, and non-obese. It is unclear whether the results will be generalizable to obese and other populations worldwide. CONCLUSIONS: Male, comorbidity, prolonged operative time, and intracorporeal anastomosis were independent risk factors of postoperative complications of laparoscopic right colectomy. Side-to-side anastomosis was associated with an increased risk of organ/space surgical site infection. Extracorporeal anastomosis could reduce the incidence of overall surgical site infection. Diabetes and conversion to open surgery were associated with an increased risk of incisional surgical site infection. See Video Abstract.

Quantifying Atomically Dispersed Catalysts Using Deep Learning Assisted Microscopy.

The catalytic performance of atomically dispersed catalysts (ADCs) is greatly influenced by their atomic configurations, such as atom-atom distances, clustering of atoms into dimers and trimers, and their distributions. Scanning transmission electron microscopy (STEM) is a powerful technique for imaging ADCs at the atomic scale; however, most STEM analyses of ADCs thus far have relied on human labeling, making it difficult to analyze large data sets. Here, we introduce a convolutional neural network (CNN)-based algorithm capable of quantifying the spatial arrangement of different adatom configurations. The algorithm was tested on different ADCs with varying support crystallinity and homogeneity. Results show that our algorithm can accurately identify atom positions and effectively analyze large data sets. This work provides a robust method to overcome a major bottleneck in STEM analysis for ADC catalyst research. We highlight the potential of this method to serve as an on-the-fly analysis tool for catalysts in future in situ microscopy experiments.

Single-cell profiling of human CD127+ innate lymphoid cells reveals diverse immune phenotypes in hepatocellular carcinoma.

BACKGROUND AND AIMS: Innate lymphoid cells (ILCs) are tissue-resident lymphocytes that play critical roles in cytokine-mediated regulation of homeostasis and inflammation. However, relationships between their immune phenotypic characteristics and HCC remain largely unexplored. APPROACH AND RESULTS: We performed single-cell RNA sequencing analysis on sorted hepatic ILC cells from human patients with HCC and validated using flow cytometry, multiplex immunofluorescence staining, and functional experiments. Moreover, we applied selection strategies to enrich ILC populations in HCC samples to investigate the effects of B cells on the immune reaction of inducible T cell costimulator (ICOS)+ ILC2 cells. Dysregulation of ILCs was manifested by the changes in cell numbers or subset proportions in HCC. Seven subsets of 3433 ILCs were identified with unique properties, of which ICOS+ ILC2a were preferentially enriched in HCC and correlated with poor prognosis. Mechanistically, we report that B cells, particularly resting naïve B cells, have a previously unrecognized function that is involved in inflammatory differentiation of ILC2 cells. B cell-derived ICOSL signaling was responsible for exacerbating inflammation through the increased production of IL-13 in ICOS+ ILC2a cells. Heat shock protein 70 (HSP70) genes Heat Shock Protein Family A Member 1A (HSPA1A) and Heat Shock Protein Family A Member 1B (HSPA1B) were highly expressed in ILC2s in late-stage HCC, and targeting to ICOS and its downstream effector HSP70 in ILC2s suppressed tumor growth and remodeled the immunosuppressive tumor microenvironment. CONCLUSIONS: This in-depth understanding sheds light on B cell-driven innate type 2 inflammation and provides a potential strategy for HCC immunotherapy.

[6,6'-2 H2 ] fructose as a deuterium metabolic imaging probe in liver cancer.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths. Imaging plays a crucial role in the early detection of HCC, although current methods are limited in their ability to characterize liver lesions. Most recently, deuterium metabolic imaging (DMI) has been demonstrated as a powerful technique for the imaging of metabolism in vivo. Here, we assess the metabolic flux of [6,6'-2 H2 ] fructose in cell cultures and in subcutaneous mouse models at 9.4 T. We compare these rates with the most widely used DMI probe, [6,6'-2 H2 ] glucose, exploring the possibility of developing 2 H fructose to overcome the limitations of glucose as a novel DMI probe for detecting liver tumors. Comparison of the in vitro metabolic rates implies their similar glycolytic metabolism in the TCA cycle due to comparable production rates of 2 H glutamate/glutamine (glx) for the two precursors, but overall higher glycolytic metabolism from 2 H glucose because of a higher production rate of 2 H lactate. In vivo kinetic studies suggest that HDO can serve as a robust reporter for the consumption of the precursors in liver tumors. As fructose is predominantly metabolized in the liver, deuterated water (HDO) produced from 2 H fructose is probably less contaminated from whole-body metabolism in comparison with glucose. Moreover, in studies of the normal liver, 2 H fructose is readily converted to 2 H glx, enabling the characterization of 2 H fructose kinetics. This overcomes a major limitation of previous 2 H glucose studies in the liver, which were unable to confidently discern metabolic flux due to overlapped signals of 2 H glucose and its metabolic product, 2 H glycogen. This suggests a unique role for 2 H fructose metabolism in HCC and the normal liver, making it a useful approach for assessing liver-related diseases and the progression to oncogenesis.

Intracorporeal Anastomosis Versus Extracorporeal Anastomosis in Laparoscopic Right Colectomy: An Observational Cohort Study.

BACKGROUND: Current studies did not draw definitive conclusions on comparison of intracorporeal anastomosis (ICA) with extracorporeal anastomosis (ECA) in laparoscopic right colectomy. Whether the intraperitoneal contamination induced by ICA can result in higher risk of postoperative abdominal infection remains unclear. This study was aimed to compare the short-term outcomes, especially the risk of abdominal infection after ICA versus ECA. METHODS: This was an observational cohort study as a secondary analysis of a randomized controlled trial (RCT)-RELARC trial (NCT02619942). The patients enrolled in the RELARC trial were diagnosed with primary colon adenocarcinoma without distant metastasis and underwent radical laparoscopic right colectomy between Jan 2016 and Dec 2019. In our study the patients who converted to open surgery in RELARC trial were excluded. The short-term outcomes were compared between ICA and ECA. The primary endpoint was abdominal infection. The inverse probability of treatment weighting (IPTW) and propensity score matching (PSM) was used for adjusting the potential confounders. RESULTS: This study enrolled 975 patients with 119 patients undergoing ICA and 856 patients undergoing ECA. The incidence of abdominal infection was higher in ICA group (9.2% versus 1.5%, RR from IPTW = 5.7 (95%CI: 2.6-12.6), P < 0.001) as well as the incidence of wound infection (14.3% vs 3.3%, RR from IPTW = 5.0 (95%CI: 2.9-8.6), P < 0.001). ICA was associated with higher incidence of Clavien-Dindo (CD) grade I and II complications (CD-I: 15.1% versus 6.8%, RR from IPTW = 2.4 (95%CI: 1.5-3.9), P < 0.001; CD-II: 26.9% versus 8.2%, RR from IPTW = 3.6 (95%CI: 2.5-5.1), P < 0.001) but similar incidence of CD-III ~ IV complications compared to ECA (3.4% vs 2.1%, RR from IPTW = 1.2 (95%CI: 0.4-4.0), P = 0.73). In ICA group, choosing another incision rather than lengthening main port site decreased the incidence of wound infection although without statistical significance (17.3% (14/81) versus 7.9% (3/38), crude RR = 2.2 (95%CI: 0.7-7.2), P = 0.17). CONCLUSION: ICA is likely to be associated with higher risk of abdominal infection and CD-I ~ II complications.

Knockdown circTRIM28 enhances tamoxifen sensitivity via the miR-409-3p/HMGA2 axis in breast cancer.

BACKGROUND: Tamoxifen (TAM) is a frequently-used treatment for breast cancer (BC). But the TAM resistance seriously affects the patient therapeutic effect. Previous research indicated that circular RNAs (circRNAs) might participate in the regulatory processes of BC. Here, we discovered the parts of circular RNA tripartite motif-containing 28 (circTRIM28) in BC. METHODS: CircTRIM28, microRNA-409-3p (miR-409-3p), and high mobility group AT-hook 2 (HMGA2) levels were perceived by qRT-PCR and western blot. Moreover, the biological functions of the cells were examined. Furthermore, dual-luciferase report was employed to reconnoiter the targeted relationship between miR-409-3p and circTRIM28 or HMGA2. RESULTS: CircTRIM28 and HMGA2 were augmented, and the miR-409-3p was repressed in BC. Silencing circTRIM28 enhanced tamoxifen sensitivity and cell apoptosis, whereas hampered cell development in BC cells. In mechanism, circTRIM28 could sponge miR-409-3p to increase HMGA2. In addition, silencing circTRIM28 impeded tumor growth. CONCLUSION: CircTRIM28 facilitated the BC via miR-409-3p/HMGA2.

Construction and validation of molecular subtypes of coronary artery disease based on ferroptosis-related genes.

BACKGROUND: This study aims to construct a reliable diagnostic model for coronary artery disease (CAD) patients and explore its potential mechanism by consensus molecular subtypes of ferroptosis-related genes. METHODS: GSE12288 and GSE20680 were downloaded from Gene Expression Omnibus database. CAD patients were divided into different molecular subtypes according to the expression level of ferroptosis-related genes. Then, the distribution of differentially expressed genes, functional annotations and immune infiltration cells between the two subtypes were compared. Finally, a prognostic model of ferroptosis-related genes in CAD was constructed and verified. RESULTS: Two different molecular subtypes of CAD were obtained according to the expression level of ferroptosis-related genes. Then, a total of 1944 differentially expressed genes (DEGs) were found, among which, 236 genes were up-regulated and 1708 genes were down-regulated. In addition, 43 DEGs were ferroptosis-related genes. Functional enrichment analysis showed that these DEGs between two subtypes of CAD were mainly enriched in immune-related pathways and processes, such as T cell receptor, mTOR, NOD-like receptor and Toll-like receptor signaling pathways. We also found that 21 immune cells were significantly changed between two subtypes of CAD. The LASSO method was performed to identify and construct the 16 ferroptosis-related genes-based diagnostic signature. Diagnostic efficiency of diagnostic signature measured by AUC in the training set and validation cohort was 0.971 and 0.899, respectively. CONCLUSIONS: This study contributes to a more comprehensive understanding of the mechanism of ferroptosis-related genes in CAD.

Short-term outcomes of complete mesocolic excision versus D2 dissection in patients undergoing laparoscopic colectomy for right colon cancer (RELARC): a randomised, controlled, phase 3, superiority trial.

BACKGROUND: Whether extended lymphadenectomy for right colon cancer leads to increased perioperative complications or improves survival is still controversial. This trial aimed to compare the efficacy and safety of complete mesocolic excision (CME) versus D2 dissection in laparoscopic right hemicolectomy for patients with right colon cancer. This article reports the early safety results from the trial. METHODS: This randomised, controlled, phase 3, superiority, trial was done at 17 hospitals in nine provinces of China. Eligible patients were aged 18-75 years with histologically confirmed primary adenocarcinoma located between the caecum and the right third of the transverse colon, without evidence of distant metastases. Central randomisation was done by means of the Clinical Information Management-Central Randomisation System via block randomisation (block size of four). Patients were randomly assigned (1:1) to CME or D2 dissection during laparoscopic right colectomy. Central lymph nodes were dissected in the CME but not in the D2 procedure. Neither investigators nor patients were masked to their group assignment but the quality control committee were masked to group assignment. The primary endpoint was 3-year disease-free survival, but the data for this endpoint are not yet mature; thus, only the secondary outcomes-intraoperative surgical complications and postoperative complications within 30 days of surgery, graded according to the Clavien-Dindo classification, mortality (death from any cause within 30 days of surgery), and central lymph node metastasis rate in the CME group only-are reported in this Article. This early analysis of safety was preplanned. The outcomes were analysed according to a modified intention-to-treat principle (excluding patients who no longer met inclusion criteria after surgery or who did not have surgery). This study is registered with ClinicalTrials.gov, NCT02619942. Study recruitment is complete, and follow-up is ongoing. FINDINGS: Between Jan 11, 2016, and Dec 26, 2019, 1072 patients were enrolled and randomly assigned. After exclusion of 77 patients, 995 patients were included in the modified intention-to-treat population (495 in the CME group and 500 in the D2 dissection group). The postoperative surgical complication rate was 20% (97 of 495 patients) in the CME group versus 22% (109 of 500 patients) in the D2 group (difference, -2·2% [95% CI -7·2 to 2·8]; p=0·39); the frequency of Clavien-Dindo grade I-II complications were similar between groups (91 [18%] vs 92 [18%], difference, -0·0% [95% CI -4·8 to 4·8]; p=1·0) but Clavien-Dindo grade III-IV complications were significantly less frequent in the CME group than in the D2 group (six [1%] vs 17 [3%], -2·2% [-4·1 to -0·3]; p=0·022); no deaths occurred in either group. Of the intraoperative complications, vascular injury was significantly more common in the CME group than in the D2 group (15 [3%] vs six [1%], difference, 1·8 [95% CI 0·04 to 3·6]; p=0·045). Metastases in the central lymph nodes were detected in 13 (3%) of 394 patients who underwent central lymph node biopsy in the CME group; no patient had isolated metastases to central lymph nodes. INTERPRETATION: Although the CME procedure might increase the risk of intraoperative vascular injury, it generally seems to be safe and feasible for experienced surgeons. FUNDING: The Capital Characteristic Clinical Project of Beijing and the Chinese Academy of Medical Sciences.

Control of Liquid Crystal Microarray Optical Signals Using a Microspectral Mode Based on Photonic Crystal Structures.

Herein, a novel liquid crystal microarray (LCM) film with optical regulation ability is first constructed by combining liquid crystals (LC) and the highly ordered microporous structure of inverse opal photonic crystals (IOPhCs). The LCM films are fabricated by infiltrating LC molecules into the LC polymer with the structure of IOPhCs, and their properties are very different from those without the LC. Interestingly, the optical property of LCM films can be controlled by changing the orientation of LC molecules, which varies with the interfacial force. In combination with polarization images, spectral reflection peak, circular dichroism spectra, potential difference, and fluorescence images of LCM films, the mechanism of this change is investigated. It is found that the exposed basic group of single-stranded DNA is the key to the change of the optical property of LC microarrays. Meanwhile, the optical signals of LC microarrays based on the PhCs provide a novel LC signal mode for an LC sensing system (microspectral signal mode), and it can be recorded by a fiber-optic spectrometer, which is a great improvement on LC sensing signals. Therefore, the LC microarray sensing signal can be used for accurate analysis of targets by the change of the reflection peak intensity of PhCs. When the LC molecules are induced by different aptamers, the LC microarray sensing interface can be further used for the determination of different targets, such as cocaine and Hg2+. The research on LCM films is of significant value for the development of LC sensing technology and also shows great application prospects in biochemical sensing fields.

Application of 15N2-Diazirines as a Versatile Platform for Hyperpolarization of Biological Molecules by d-DNP.

15N2-Diazirines represent an attractive class of imaging tags for hyperpolarized magnetic resonance imaging (HP-MRI), offering desirable biocompatibility, ease of incorporation into a variety of molecules, and ability to deliver long-lasting polarization. We have recently established hyperpolarization of 15N2-diazirines in organic solvents using SABRE-Shield Enables Alignment Transfer to Heteronuclei (SABRE-SHEATH). Yet, the current challenge of SABRE-SHEATH in water, specifically poor polarization efficiency, presents a barrier in examining the practical use of 15N2-diazirines for HP-MRI. Herein, we show that efficient polarization of diverse 15N2-diazirine-labeled molecules in water can be readily achieved by dissolution dynamic nuclear polarization (d-DNP), a hyperpolarization technique used in clinical practice. Hyperpolarization by d-DNP also demonstrates greater enhancement for long-lasting 15N signals, in comparison with SABRE-SHEATH. Various biologically important molecules are studied in this work, including amino acid, sugar, and drug compounds, demonstrating the great potential of 15N2-diazirines as molecular tags in broad biomedical and clinical applications.

Laparoscopic resection of large retrorectal developmental cysts in adults: Single-centre experiences of 20 cases.

Context: Retrorectal tumours are rare with developmental cysts being the most common type. Conventionally, large retrorectal developmental cysts (RRDCs) require the combined transabdomino-sacrococcygeal approach. Aims: This study aims to investigate the surgical outcomes of the laparoscopic approach for large RRDCs. Settings and Design: A retrospective case series analysis. Subjects and Methods: Data of patients with RRDCs of 10 cm or larger in diameter who underwent the laparoscopic surgery between 2012 and 2017 at our tertiary centre were retrospectively analyzed. Statistical Analysis Used: Results are presented as median values or mean ± standard deviation for continuous variables and numbers (percentages) for categorical variables. Results: Twenty consecutive cases were identified (19 females; median age, 36 years). Average tumour size was 10.9 ± 1.1 cm. Cephalic ends of lesions ranged from S1/2 junction to S4 level. Caudally, 18 cysts extended to the sacrococcygeal hypodermis. Seventeen patients underwent the pure laparoscopy; three patients received a combined laparoscopic-posterior approach. The operating time was 167.1 ± 57.3 min for the pure laparoscopic group and 212.0 ± 24.5 min for the combined group. The intraoperative haemorrhage was 68.2 ± 49.7 and 66.7 ± 28.9 (mL), respectively. Post-operative complications included one trocar site hernia, one wound infection and one delayed rectal wall perforation. The median post-operative hospital stay was 7 days. With a median follow-up period of 36 months, 1 lesions recurred. Conclusions: The laparoscopic approach can provide a feasible and effective alternative for large RRDCs, with advantages of the minimally invasive surgery. For lesions with ultra-low caudal ends, especially those closely clinging to the rectum, a combined posterior approach is still necessary.

Iodonitrene in Action: Direct Transformation of Amino Acids into Terminal Diazirines and 15N2-Diazirines and Their Application as Hyperpolarized Markers.

A one-pot metal-free conversion of unprotected amino acids to terminal diazirines has been developed using phenyliodonium diacetate (PIDA) and ammonia. This PIDA-mediated transformation occurs via three consecutive reactions and involves an iodonitrene intermediate. This method is tolerant to most functional groups found on the lateral chain of amino acids, it is operationally simple, and it can be scaled up to provide multigram quantities of diazirine. Interestingly, we also demonstrated that this transformation could be applied to dipeptides without racemization. Furthermore, 14N2 and 15N2 isotopomers can be obtained, emphasizing a key trans-imination step when using 15NH3. In addition, we report the first experimental observation of 14N/15N isotopomers directly creating an asymmetric carbon. Finally, the 15N2-diazirine from l-tyrosine was hyperpolarized by a parahydrogen-based method (SABRE-SHEATH), demonstrating the products' utility as hyperpolarized molecular tag.

LncRNA H19 regulates PI3K-Akt signal pathway by functioning as a ceRNA and predicts poor prognosis in colorectal cancer: integrative analysis of dysregulated ncRNA-associated ceRNA network.

BACKGROUND: It is becoming increasingly clear that cancers can rarely be ascribed to just one or a few genomic variations. Genes generally do not function alone, but in groups that function as "networks". This study aimed to develop a competing endogenous RNA (ceRNA) network to elucidate the role of long non-coding RNA H19 in colorectal cancer. METHODS: Large-scale RNA-seq data was obtained from The Cancer Genome Atlas database. Differentially expressed RNAs were identified by bioinformatics analysis, and a competing endogenous RNA network was constructed. Functional enrichment analysis and correlation analysis between competing endogenous RNAs and clinical features were performed to reveal their roles in the tumorigenesis of colorectal cancer. To verify the conclusions derived from bioinformatics analysis, we investigated the effect of lncRNA H19 knockdown in human colorectal cancer cell lines HT-29 and HCT116. RESULTS: The present study successfully identify various cancer-specific lncRNAs and pseudogenes in CRC. The lncRNA/pseudogene-miRNA-mRNA ceRNA network was constructed using 10 lncRNAs, 5 pseudogenes, 122 mRNAs and 39 miRNAs. In the ceRNA network of CRC, H19 up-regulates various cancer-related mRNA by competitively sponging various miRNA, and participates in PI3K-Akt signaling pathway in this manner. Cox regression and correlation analysis showed that H19 and some other competing endogenous RNAs in the network are associated with poor prognosis and clinical parameters such as tumor grade and metastasis. Knockdown of H19 reduces the protein level of MET, ZEB1, and COL1A1 in vitro. CONCLUSIONS: H19 regulates PI3K-Akt signal pathway through a competing endogenous RNA network and predicts poor prognosis in colorectal cancer. The pseudogene RPLP0P2 may be an important oncogene like H19 and needs to be studied further.

Sensing of cocaine using polarized optical microscopy by exploiting the conformational changes of an aptamer at the water/liquid crystal interface.

Liquid crystals (LCs) have the ability to transduce and amplify a molecular stimulus into optical signals due to their elastic and birefringence properties. An aptamer-based LC sensor for cocaine is described here. 3-Morpholinopropanesulfonic acid with amphipathic structure was used to establish recognition sites at a water/LC interface for the detection of cocaine. The cocaine-binding aptamer is formed at the interface. The conformation of the aptamer undergoes a change on binding cocaine, and this triggers the LCs anchoring transition from homeotropic to planar. Binding can also be detected by polarized optical microscopy. The fluorescence spectroscopy and circular dichroism results are used to prove that the conformation of aptamer changed from a hairpin structure to a special three-way junction structure on binding of cocaine at the interface. The assay works in the 1 nM to 10 µM cocaine concentration range and is specific. Graphical abstract Schematic representation of aptamer-based liquid crystal (LC) biosensor for the detection of cocaine. In this interface biosensing system, after the aptamer binding with cocaine, the conformation of aptamer at the aqueous/LC interface was changed from a hairpin structure to a special three-way junction structure. This triggered the Liquid crystals (LCs) anchoring transition from homeotropic to planar and the sign-on optical signal could be obtained by polarizing optical microscope (POM) in real-time.

Robotic versus conventional laparoscopic surgery for rectal cancer: systematic review and meta-analysis.

BACKGROUND: The purpose of this meta-analysis is to evaluate the evidence available on the safety as well as effectiveness of robotic resection as compared to conventional laparoscopic surgery for rectal cancer. MATERIAL AND METHODS: A comparison of laparoscopic and robotic surgical treatments for rectal cancer was collected. Eligible trials that analyzed probabilistic hazard ratios (HR) for endpoints of interest (including perioperative morbidity) and postoperative complications were included in our review. RESULTS: A total of six studies were included based on the present inclusion criteria. The pooled data showed that R-TME appeared to have association with remarkable reduction in the postoperative morbidity rate as compared to L-TME. Moreover, R-TME was also linked to lower conversion, decreased lymph node number, and longer operation time compared with L-TME. However, there was no difference in hospital stay, positive range of circumferential resection and blood loss between the two study groups. CONCLUSIONS: Robotic rectal cancer surgery provides favorable outcomes and is considered as a safe surgical technique in terms of postoperative oncological safety. Like laparoscopic TME surgery, robotic surgery may be a valid alternative and complementary approach with beneficial effects on minimally-invasive surgery.

Terminal Diazirines Enable Reverse Polarization Transfer from 15 N2 Singlets.

Diazirine moieties are chemically stable and have been incorporated into biomolecules without impediment of biological activity. The 15 N2 labeled diazirines are appealing motifs for hyperpolarization supporting relaxation protected states with long-lived lifetimes. The (-CH15 N2 ) diazirine groups investigated here are analogues to methyl groups, which provides the opportunity to transfer polarization stored on a relaxation protected (-CH15 N2 ) moiety to 1 H, thus combining the advantages of long lifetimes of 15 N polarization with superior sensitivity of 1 H detection. Despite the proximity of 1 H to 15 N nuclei in the diazirine moiety, 15 N T1 times of up to (4.6±0.4) min and singlet lifetimes Ts of up to (17.5±3.8) min are observed. Furthermore, we found terminal diazirines to support hyperpolarized 1 H2 singlet states in CH2 groups of chiral molecules. The singlet lifetime of 1 H singlets is up to (9.2±1.8) min, thus exceeding 1 H T1 relaxation time (at 8.45 T) by a factor of ≈100.