Blockade of the lncRNA-DOT1L-LAMP5 axis enhances autophagy and promotes degradation of MLL fusion proteins.

BACKGROUND: Mixed-lineage leukemia (MLL) fusion gene caused by chromosomal rearrangement is a dominant oncogenic driver in leukemia. Due to having diverse MLL rearrangements and complex characteristics, MLL leukemia treated by currently available strategies is frequently associated with a poor outcome. Therefore, there is an urgent need to identify novel therapeutic targets for hematological malignancies with MLL rearrangements. METHODS: qRT-PCR, western blot, and spearman correction analysis were used to validate the regulation of LAMP5-AS1 on LAMP5 expression. In vitro and in vivo experiments were conducted to assess the functional relevance of LAMP5-AS1 in MLL leukemia cell survival. We utilized chromatin isolation by RNA purification (ChIRP) assay, RNA pull-down assay, chromatin immunoprecipitation (ChIP), RNA fluorescence in situ hybridization (FISH), and immunofluorescence to elucidate the relationship among LAMP5-AS1, DOT1L, and the LAMP5 locus. Autophagy regulation by LAMP5-AS1 was evaluated through LC3B puncta, autolysosome observation via transmission electron microscopy (TEM), and mRFP-GFP-LC3 puncta in autophagic flux. RESULTS: The study shows the crucial role of LAMP5-AS1 in promoting MLL leukemia cell survival. LAMP5-AS1 acts as a novel autophagic suppressor, safeguarding MLL fusion proteins from autophagic degradation. Knocking down LAMP5-AS1 significantly induced apoptosis in MLL leukemia cell lines and primary cells and extended the survival of mice in vivo. Mechanistically, LAMP5-AS1 recruits the H3K79 histone methyltransferase DOT1L to LAMP5 locus, directly activating LAMP5 expression. Importantly, blockade of LAMP5-AS1-LAMP5 axis can represses MLL fusion proteins by enhancing their degradation. CONCLUSIONS: The findings underscore the significance of LAMP5-AS1 in MLL leukemia progression through the regulation of the autophagy pathway. Additionally, this study unveils the novel lncRNA-DOT1L-LAMP5 axis as promising therapeutic targets for degrading MLL fusion proteins.

Ir/Zn-cocatalyzed chemo- and atroposelective [2+2+2] cycloaddition for construction of C─N axially chiral indoles and pyrroles.

Here, an Ir/Zn-cocatalyzed atroposelective [2+2+2] cycloaddition of 1,6-diynes and ynamines was developed, forging various functionalized C─N axially chiral indoles and pyrroles in generally good to excellent yields (up to 99%), excellent chemoselectivities, and high enantioselectivities (up to 98% enantiomeric excess) with wide substrate scope. This cocatalyzed strategy not only provided an alternative promising and reliable way for asymmetric alkyne [2+2+2] cyclotrimerization in an easy handle but also settled the issues of previous [Rh(COD)2]BF4-catalyzed system on the construction of C─N axial chirality such as complex operations, limited substrate scope, and low efficiency. In addition, control experiments and theoretical calculations disclosed that Zn(OTf)2 markedly reduced the barrier of migration insertion to significantly increase reaction efficiency, which was distinctly different from previous work on the Lewis acid for improving reaction yield through accelerating oxidative addition and reductive elimination.

New insight into circRNAs: characterization, strategies, and biomedical applications.

Circular RNAs (circRNAs) are a class of covalently closed, endogenous ncRNAs. Most circRNAs are derived from exonic or intronic sequences by precursor RNA back-splicing. Advanced high-throughput RNA sequencing and experimental technologies have enabled the extensive identification and characterization of circRNAs, such as novel types of biogenesis, tissue-specific and cell-specific expression patterns, epigenetic regulation, translation potential, localization and metabolism. Increasing evidence has revealed that circRNAs participate in diverse cellular processes, and their dysregulation is involved in the pathogenesis of various diseases, particularly cancer. In this review, we systematically discuss the characterization of circRNAs, databases, challenges for circRNA discovery, new insight into strategies used in circRNA studies and biomedical applications. Although recent studies have advanced the understanding of circRNAs, advanced knowledge and approaches for circRNA annotation, functional characterization and biomedical applications are continuously needed to provide new insights into circRNAs. The emergence of circRNA-based protein translation strategy will be a promising direction in the field of biomedicine.

Diagnostic performance of gadoxetic acid-enhanced abbreviated magnetic resonance imaging protocol in small hepatocellular carcinoma (≤2 cm) in high-risk patients.

BACKGROUND: Biannual Ultrasound showed insufficient sensitivity in detecting small or early-stage hepatocellular carcinoma (HCC). Abbreviated magnetic resonance imaging (A-MRI) protocols with fewer sequences demonstrated higher HCC detection sensitivity than ultrasound with acceptable cost and examination time. PURPOSE: To compare the diagnostic performance of gadoxetic acid-enhanced A-MRI with a full sequence MRI (F-MRI) protocol for small HCC (≤2 cm) in cirrhotic or hepatitis B virus-infected high-risk patients. MATERIAL AND METHODS: Two hundred and four consecutive patients with 166 pathologically confirmed small HCC who underwent preoperative gadoxetic acid-enhanced MRI were retrospectively included. A-MRI set comprised T1-weighted hepatobiliary phase imaging, T2-weighted imaging, diffusion-weighted imaging and apparent diffusion coefficient mapping. Two independent radiologists blinded to clinical data assessed the A-MRI set and F-MRI set. Per-patient HCC and per-lesion HCC diagnostic performance were compared. RESULTS: Per-patient HCC detection sensitivity of A-MRI set was 93.8% and 91.2% for observer 1 and observer 2, and, for the F-MRI set, the per-patient HCC detection sensitivity was 96.6% and 95.2%, respectively. There was no significant difference in per-patient sensitivity, specificity and per-lesion HCC detection sensitivity between the two imaging sets for both readers. (P = 0.06-0.25) The A-MRI set showed higher sensitivity on HCC without arterial phase hyperenhancement, and the F-MRI set demonstrated with higher sensitivity on HCC with arterial phase hyperenhancement (P < 0.05). CONCLUSION: A-MRI using diagnostic criteria including hypointensity on hepatobiliary phase plus mild to moderate hyperintensity on T2-weighted imaging or restricted diffusion demonstrated comparable sensitivity and specificity for small HCC compared to the F-MRI protocol in high-risk patients.

The Elk-3 target Abhd10 ameliorates hepatotoxic injury and fibrosis in alcoholic liver disease.

Alcoholic liver disease (ALD) and other forms of chronic hepatotoxic injury can lead to transforming growth factor ß1 (TGFß1)-induced hepatic fibrosis and compromised liver function, underscoring the need to develop novel treatments for these conditions. Herein, our analyses of liver tissue samples from severe alcoholic hepatitis (SAH) patients and two murine models of ALD reveals that the ALD phenotype was associated with upregulation of the transcription factor ETS domain-containing protein (ELK-3) and ELK-3 signaling activity coupled with downregulation of α/ß hydrolase domain containing 10 (ABHD10) and upregulation of deactivating S-palmitoylation of the antioxidant protein Peroxiredoxin 5 (PRDX5). In vitro, we further demonstrate that ELK-3 can directly bind to the ABHD10 promoter to inhibit its transactivation. TGFß1 and epidermal growth factor (EGF) signaling induce ABHD10 downregulation and PRDX5 S-palmitoylation via ELK-3. This ELK-3-mediated ABHD10 downregulation drives oxidative stress and disrupts mature hepatocyte function via enhancing S-palmitoylation of PRDX5's Cys100 residue. In vivo, ectopic Abhd10 overexpression ameliorates liver damage in ALD model mice. Overall, these data suggest that the therapeutic targeting of the ABHD10-PRDX5 axis may represent a viable approach to treating ALD and other forms of hepatotoxicity.

[Status Quo and Development of Immunotherapy for Hepatocellular Carcinoma].

Liver cancer is a serious global health problem and a common cause of cancer-related death. Hepatocellular carcinoma (HCC) is a common pathological type of liver cancer. The clinical symptoms of early HCC tend to be not obvious and 50% of HCC patients are already in the advanced stage by the time they are diagnosed. Systemic therapy is recommended for the treatment of advanced HCC. With the development of molecular targeted drugs (sorafenib and lenvatinib), some progress has been made in the systemic treatment of advanced HCC, but there is only modest benefit for the survival of HCC patients. In recent years, the emergence of immune checkpoint inhibitors has changed the overall outlook of HCC treatment, providing more possibilities for precise treatment of HCC and showing better treatment outcomes. In particular, the combination therapy of atezolizumab and bevacizumab significantly improved the survival outcomes in HCC patients. In addition, adoptive cell therapy, tumor vaccine, oncolytic viruses, and nonspecific immunotherapy have also emerged as strategies for immunotherapy. Herein, the status quo and development of HCC immunotherapy are reviewed.

Current management of avascular necrosis of the metacarpal head: a comprehensive literature review.

BACKGROUND: Avascular necrosis (AVN) of the metacarpal head is a rare disease that may lead to progressive destruction of the metacarpophalangeal joint and hand function. This study aimed to describe the epidemiology, possible risk factors, clinical presentation, diagnostic workup, and treatment of the rare condition of avascular necrosis of the metacarpal head. METHODS: Articles were searched using the subject words "Dieterich disease","Mauclaire's disease", and "avascular necrosis of metacarpal head" in the PubMed and Scopus databases. Studies were retained for review after meeting the inclusion criteria. Those outcomes relevant to diagnose and assessing AVN of the metacarpal head and those related to curative management were extracted. RESULTS: The literature search revealed 45 studies with 55 patients. Although the aetiology of osteonecrosis has not been clearly delineated, AVN of the metacarpal head most commonly arises from trauma but other risk factors may also be involved. Plain radiographs are often negative and therefore likely to be missed. Early-stage osteonecrosis of the metacarpal head was best assessed using MRI. Given the rarity of this condition, there is no clear consensus on the treatment. CONCLUSIONS: Avascular necrosis of the metacarpal head should be considered in the differential diagnosis of painful metacarpophalangeal joints. An early understanding of this unusual disease will provide an optimal clinical outcome, restoring joint activity, and resolving pain. Nonoperative treatment cannot cure all patients. Surgical management is based on the patient and lesion characteristics.

METTL3 protects METTL14 from STUB1-mediated degradation to maintain m6 A homeostasis.

N6 -Methyladenosine (m6 A) is an important RNA modification catalyzed by methyltransferase-like 3 (METTL3) and METTL14. m6 A homeostasis mediated by the methyltransferase (MTase) complex plays key roles in various biological processes. However, the mechanism underlying METTL14 protein stability and its role in m6 A homeostasis remain elusive. Here, we show that METTL14 stability is regulated by the competitive interaction of METTL3 with the E3 ligase STUB1. STUB1 directly interacts with METTL14 to mediate its ubiquitination at lysine residues K148, K156, and K162 for subsequent degradation, resulting in a significant decrease in total m6 A levels. The amino acid regions 450-454 and 464-480 of METTL3 are essential to promote METTL14 stabilization. Changes in STUB1 expression affect METTL14 protein levels, m6 A modification and tumorigenesis. Collectively, our findings uncover an ubiquitination mechanism controlling METTL14 protein levels to fine-tune m6 A homeostasis. Finally, we present evidence that modulating STUB1 expression to degrade METTL14 could represent a promising therapeutic strategy against cancer.

Diagnostic Performance of Contrast Enhanced CT Alone or in Combination with (Non-)Enhanced MRI for Colorectal Liver Metastasis.

RATIONALE AND OBJECTIVES: To compare the diagnostic performance of contrast enhanced CT (CE-CT), CE-CT combined with non-enhanced MRI (NE-MRI) or contrast enhanced MRI (CE-MRI) for colorectal liver metastasis (CRLM). MATERIALS AND METHODS: Sixty-six colorectal cancer patients with 198 focal liver lesions who underwent preoperative abdominal CE-CT and MRI examinations were included respectively. The images were assessed independently by two readers in three protocols (1: CE-CT, 2: CE-CT+NE-MRI, 3: CE-CT+CE-MRI). The diagnostic performance of each protocol was analyzed by receiver operating characteristic (ROC) curve and the areas under ROC (AUCs) were calculated and compared. RESULTS: The detection rates of protocol 2 were 90.9%-92.9% for liver lesions and 86.4%-89.6% for CRLM, and both significantly higher than protocol 1 of 82.8%-85.4% and 76.8%-80.8% (p<0.001-0.001), whereas similar to protocol 3 of 91.9%-94.4% and 87.2%-91.2% (p 0.250-1.000). The AUCs of protocol 2 were greater than protocol 1 for all lesions (0.914-0.934 vs. 0.779-0.799, p<0.001) and lesions < 10mm (0.726-0.776 vs. 0.528-0.561, p<0.001), and were not inferior to that of protocol 3 (0.929-0.949 in all lesions and 0.754-0.821 in lesion < 10mm, p 0.053-0.162). CONCLUSION: CE-CT combined with NE-MRI offered superior diagnostic performance for CRLM compared to CE-CT alone and showed comparable performance to CE-CT combined with CE-MRI.

The snoRNA-like lncRNA LNC-SNO49AB drives leukemia by activating the RNA-editing enzyme ADAR1.

Long noncoding RNAs (lncRNAs) are usually 5' capped and 3' polyadenylated, similar to most typical mRNAs. However, recent studies revealed a type of snoRNA-related lncRNA with unique structures, leading to questions on how they are processed and how they work. Here, we identify a novel snoRNA-related lncRNA named LNC-SNO49AB containing two C/D box snoRNA sequences, SNORD49A and SNORD49B; and show that LNC-SNO49AB represents an unreported type of lncRNA with a 5'-end m7G and a 3'-end snoRNA structure. LNC-SNO49AB was found highly expressed in leukemia patient samples, and silencing LNC-SNO49AB dramatically suppressed leukemia progression in vitro and in vivo. Subcellular location indicated that the LNC-SNO49AB is mainly located in nucleolus and interacted with the nucleolar protein fibrillarin. However, we found that LNC-SNO49AB does not play a role in 2'-O-methylation regulation, a classical function of snoRNA; instead, its snoRNA structure affected the lncRNA stability. We further demonstrated that LNC-SNO49AB could directly bind to the adenosine deaminase acting on RNA 1(ADAR1) and promoted its homodimerization followed by a high RNA A-to-I editing activity. Transcriptome profiling shows that LNC-SNO49AB and ADAR1 knockdown respectively share very similar patterns of RNA modification change in downstream signaling pathways, especially in cell cycle pathways. These findings suggest a previously unknown class of snoRNA-related lncRNAs, which function via a manner in nucleolus independently on snoRNA-guide rRNA modification. This is the first report that a lncRNA regulates genome-wide RNA A-to-I editing by enhancing ADAR1 dimerization to facilitate hematopoietic malignancy, suggesting that LNC-SNO49AB may be a novel target in therapy directed to leukemia.

[Mechanism of miRNA-3679 Inhibiting Downstream ZADH2-Target Genes to Promote Hepatocellular Carcinoma Cell Proliferation].

Objective: To examine the relationship between miRNA-3679 and hepatocellular carcinoma (HCC) cell lines, and to verify the downstream target genes of miRNA-3679. Methods: PCR was used to determine the expression of miRNA-3679 in liver cancer cell lines, and databases, including ENCORI, miRDB and TargetScan, were used to predict the downstream target genes of miRNA-3679. qPCR of the normal control group (or NC group), miR-3679 inhibitor group and transfection negative control group (or inhibitor NC group) was done to determine the transfection efficiency of the target gene, thereby identifying zinc-binding alcohol dehydrogenase domain containing 2 (ZADH2) as the target gene. Western blot was used to determine the ZADH2 protein expression after miRNA-3679 inhibitor transfection. 5-Ethynyl-2'-deoxyuridine (EdU) staining was done to determine the effect of transfection of miRNA-3679 inhibitor and simultaneous transfection of miRNA-3679 and ZADH2 inhibitors on cell proliferation. Clone formation assay was done to determine the ability of cell clone formation. Flow cytometry was done to examine cell apoptosis. Results: The expression level of miRNA-3679 in HCC cell lines was higher than that in normal human liver cell lines (P<0.05). Through screening conducted with the databases, six genes, including GLUD1, B3GAT1, SLC46A3, MAP2K3, ATF5, and ZADH2, were found to be down-regulated in HCC. qPCR showed that ZADH2 expression increased significantly after transfection with miRNA-3679 inhibitor (P<0.01) and luciferase activity increased after transfection with miR-3679 inhibitor (P<0.01). Western blot results showed that ZADH2 protein expression of the miR-3679 inhibitor group was higher than that of the NC group (P<0.01). EdU analysis showed that the number of positive cells in the miRNA-3679 inhibitor group was lower than that in the NC group and the Inhibitor NC group (P<0.05). The clone count of the miR-3679 inhibitor+si-ZADH2 group was significantly higher than that of the miR-3679 inhibitor group (P<0.01). Flow cytometry showed that the number of apoptotic cells of the miR-3679 inhibitor+si-ZADH2 group was significantly lower than that of the miR-3679 inhibitor group (P<0.01). Conclusion: miRNA-3679 is significantly highly expressed in HCC cells and miRNA-3679 can directly interact with ZADH2 gene and affect its expression. Moreover, miRNA-3679 promotes the proliferation of HCC cells and inhibits their apoptosis by suppressing ZADH2.

[Relationship Between the Level of Anatomical Risk of Hepatic Alveolar Echinococcosis and Complications after Radical Resection].

Objective: To analyze the impact of high or low levels of anatomical risk of hepatic alveolar echinococcosis (HAE) on complications after radical resection. Methods: The baseline, surgical, and complication data were retrospectively collected from hepatic alveolar echinococcosis patients who underwent radical resection at the Ganzi Branch Hospital, West China Hospital, Sichuan University from 2015 to 2022. The patients were divided into anatomical low-risk (ALR) and anatomical high-risk (AHR) groups based on the PNM staging system designed by the World Health Organization (WHO-PNM). Complications were analyzed according to the Clavien-Dindo classification. Univariate and multivariate logistic regression analyses were performed to assess the effect of high and low risks of lesion anatomy on complications. Results: Radical surgery was performed in 216 HAE patients and 102 of whom were in the AHR group. The median operative time was 230 (175, 300) min, the median intraoperative blood loss was 600 mL, and 129 (59.7%) patients developed complications. The complication rate was 73.5% (75/102) in the AHR group and 47.4% (54/114) in the ALR group, demonstrating statistically significant difference ( P<0.05). The incidence of serious complications was 36.3% (37/102) in the AHR group and 13.2% (15/114) in the ALR group, demonstrating statistically significant difference ( P<0.05). There was significant difference in the proportions of patients having postoperative complications of bile leak, anemia, fever, pleural effusion and ascites between the AHR group and the ALR group ( P<0.05). Multivariate logistic regression analysis suggested that AHR was the only independent risk factor for complications, including bile leak, anemia, fever, and pleural effusion, and severe complications. Conclusion: The anatomical risk of hepatic alveolar echinococcosis is independently associated with the development of multiple postoperative complications, and physicians should choose surgical procedures cautiously according to the actual situation when dealing with patients defined as AHR according to WHO-PNM.

Sensitive Imaging of Cellular RNA via Cascaded Proximity-Induced Fluorogenic Reactions.

Owing to its important biological functions, RNA has become a promising molecular biomarker of various diseases. With a dynamic change in its expression level and a relatively low amount within the complicated biological matrix, signal amplification detection based on DNA probes has been put forward, which is helpful for early diagnosis and prognostic prediction. However, conventional methods are confined to cell lysates or dead cells and are not only time-consuming in sample preparation but also inaccessible to the spatial-temporal information of target RNAs. To achieve live-cell imaging of specific RNAs, both the detection sensitivity and intracellular delivery issues should be addressed. Herein, a new cascaded fluorogenic system based on the combination of hybridization chain reactions (HCRs) and proximity-induced bioorthogonal chemistry is developed, in which a bioorthogonal reaction pair (a tetrazine-quenched dye and its complementary dienophile) is brought into spatial proximity upon target RNA triggering the HCR to turn on and amplify the fluorescence in one step, sensitively indicating the cellular distribution of RNA with minimal false positive results caused by unspecific degradation. Facilitated by a biodegradable carrier based on black phosphorus with high loading capacity and excellent biocompatibility, the resulting imaging platform allows wash-free tracking of target RNAs inside living cells.

Torsional Strain-Independent Catalytic Enantioselective Synthesis of Biaryl Atropisomers.

Catalytic asymmetric dynamic kinetic resolution of configurationally labile bridged biaryls is emerging as a powerful strategy for atropisomer synthesis. However, the reported examples suffer from an inherent challenge as the reactivity is highly dependent on the torsional strain of the biaryl substrates, which significantly narrows down the scope and hampers the application. Herein, we report our discovery and development of a torsional strain-independent reaction between biaryl thionolactones and activated isocyanides. By employing auto-tandem silver catalysis, a universal synthesis of both tri- and tetra-ortho-substituted thiazole-containing biaryls was realized in high yields with high enantioselectivities. In addition, these products could be facilely converted to a novel type of bridged biaryls bearing an eight-membered lactone. Mechanistic studies were carried out to elucidate the cause of this unusual torsional strain-independent reactivity.

Simultaneous Construction of C-N Axial and Central Chirality via Silver-Catalyzed Desymmetrizative [3 + 2] Cycloaddition of Prochiral N-Aryl Maleimides with Activated Isocyanides.

Herein, we report an unprecedented strategy for the simultaneous construction of a remote C-N stereogenic axis and three contiguous stereogenic carbon centers via silver-catalyzed desymmetrizative [3 + 2] cycloaddition of prochiral N-aryl maleimides with activated isocyanides. This method features operational simplicity, wide substrate scope, high efficiency, and good to excellent stereoselectivity. Notably, it represents the first example of catalytic enantioselective synthesis of C-N atropisomers with the use of activated isocyanides.

MR quantitative 3D shape analysis helps to distinguish mucinous cystic neoplasm from serous oligocystic adenoma.

PURPOSE We aimed to assess the performance of quantitative 3D shape analysis in the differential diagno- sis of pancreatic serous oligocystic adenoma (SOA) and mucinous cystic neoplasm (MCN). METHODS Four hundred thirty-two patients diagnosed with serous cystic neoplasms (SCNs) or MCNs were retrospectively reviewed from August 2014 to July 2019 and finally 87 patients with MCNs (n = 45) and SOAs (n = 42) were included. Clinical data and magnetic resonance morphologic fea- tures with 3D shape analysis of lesions (shape sphericity, compacity, and volume) were recorded and compared between MCNs and SOAs according to the pathology. Univariable and multivari- able regression analyses were used to identify independent impact factors for differentiating MCN from SOA. RESULTS The age of MCN patients was younger than SOAs (43.02 ± 10.83 years vs. 52.78 ± 12.31 years; OR = 0.275; 95% CI: 0.098-0.768; P = .014). MCN has a higher female/male ratio than SOA (43/2 vs. 27/15; OR = 40.418; 95% CI: 2.704-604.171; P = .007) and was more often located in the distal of pancreas (OR = 31.403; 95% CI: 2.985-330.342; P = .004). Shape_Sphericity derived from 3D shape analysis was a significant independent factor in the multivariable analysis and the value of MCN was closer to 1 than SOA (OR = 35.153; 95% CI: 5.301-237.585; P < .001). Area under the receiver operating characteristic curve (AUC) of Shape_Sphericity was 0.923 (optimal cutoff value was 0.964876). CONCLUSION Shape_Sphericity in combination with age, sex, and location could help to distinguish MCN from SOA.

Feasibility and advantages analyses of wedge resection without mesentery detached approach applied to closure of loop ileostomy.

OBJECTIVES: To evaluate the feasibility and advantages of wedge resection plus transverse suture without mesentery detached approach applied to loop ileostomy closure by analyzing the surgical data and the incidence of postoperative complications of patients undergoing this procedure. METHODS: We performed a retrospective analysis of the hospitalization data of patients who underwent ileostomy closure surgery and met the research standards from January 2017 to April 2021 in Guangxi Medical University Cancer Hospital; all surgeries were performed by the same surgeon. The perioperative data were statistically analyzed by grouping. RESULTS: In total, 65 patients were enrolled in this study, with 12 in the wedge resection group, 35 in the stapler group, and 18 in the hand suture group. There was no significant difference in operation time between the wedge resection group and stapler group (P > 0.05), but both groups had shorter operation time than that in the hand suture group (P < 0.05). The postoperative exhaustion time of wedge resection group was earlier than that of the others, and cost of surgical consumables in the wedge resection group was significantly lower than that in the stapler group, all with statistically significant differences (P < 0.05). By contrast, there were no statistically significant differences in postoperative complication incidences among the three groups. CONCLUSIONS: The wedge resection plus transverse suture without mesentery detached approach is safe and easy for closure of loop ileostomy in selected patients, and the intestinal motility recovers rapidly postoperatively. It costs less surgical consumables, and is particularly suitable for the currently implemented Diagnosis-Related Groups payment method.

Cooperative catalysis-enabled C-N bond cleavage of biaryl lactams with activated isocyanides.

The catalytic reaction of biaryl lactams with activated isocyanides is reported for the first time. By employing a cooperative catalytic system, oxazole-containing axially chiral biaryl anilines were obtained in high yields with excellent enantioselectivities. The key to the success lies in the atroposelective amide C-N bond cleavage with activated isocyanides.

Diastereo- and Enantioselective Silver-Catalyzed [3+3] Cycloaddition and Kinetic Resolution of Azomethine Imines with Activated Isocyanides.

In contrast to the well-established [3+2] cycloaddition reactions, the catalytic enantioselective [3+n] (n≥3) cycloaddition reaction of activated isocyanides for the preparation of six-membered or larger ring systems has remained underdeveloped. Herein, we report the first example of highly diastereo- and enantioselective [3+3] cycloaddition of activated isocyanides with azomethine imines. By employing silver catalysis, a wide range of biologically important bicyclic 1,2,4-triazines were obtained in high yields (up to 99 %) with good to excellent stereoselectivities (up to >20 : 1 dr, 99 % ee). In addition, the same catalytic system could be applied to both the late-stage functionalization of complex bioactive molecules and the kinetic resolution of racemic azomethine imines, further highlighting its versatility and synthetic utility.

Chromatin-associated orphan snoRNA regulates DNA damage-mediated differentiation via a non-canonical complex.

Small nucleolar RNAs (snoRNAs) are commonly acknowledged as a class of homogeneous non-coding RNAs that guide ribosomal RNA modifications. However, snoRNAs referred to as orphans have largely unknown functions. Here, we systematically profile chromatin-associated snoRNAs (casnoRNAs) in mammalian cells and identify a subgroup of orphan casnoRNAs responding to DNA damage stress, among which SNORA73 shows the most marked reduction in chromatin enrichment. Downregulated SNORA73 maintains cancer genome stability and differentiation block in hematopoietic malignancy. Mechanistically, casnoRNA the 5' end non-canonical structure of SNORA73 is critical for its function and binding to poly (ADP-ribose) polymerase 1 (PARP1). SNORA73 inhibits PARP1 auto-PARylation to affect cancer genome stability by forming a small nucleolar ribonucleoprotein (snoRNP) with PARP1 and canonical H/ACA proteins DKC1/NHP2. Our findings reveal the role of an orphan snoRNA serving as casnoRNA and highlights a link between non-canonical structure of snoRNA and their functional diversity.