Publications by authors named "ChunXiao Sun"

Cyclopentachromone, distinguished by its 6/6/5 heterotricyclic ring structure, is a key building block in many bioactive natural products, yet its enzymatic origin remains unclear. We identified a new class of cyclopentachromone-containing compounds, termed isochromosulfines, characterized by unique C-S bonds. A distinct FAD-dependent monooxygenase, IscL, was identified to catalyze the formation of the 6/6/5 cyclopentadiene intermediate, 2-remisporine A, from a 6/6/6 xanthone precursor via benzene ring contraction.

View Article and Find Full Text PDF

Human epidermal growth factor receptor 2 (HER2)-low breast cancer is a newly identified targetable subset of breast tumors, and its clinical characteristics and treatment strategies are controversial. The emergence of novel anti-HER2 antibody-drug conjugate (ADC) has brought promising approaches for HER2-low breast cancer treatment. Several clinical trials have validated the efficacy and safety of trastuzumab deruxtecan (T-Dxd) in HER2-low breast cancer at different treatment settings.

View Article and Find Full Text PDF
Article Synopsis
  • Fungal ribosomally synthesized and post-translationally modified peptides (RiPPs) are important natural products with various biological activities such as anticancer and immunosuppressive effects.
  • Despite their significance, discovering these compounds has been difficult, leading to only a few identified types that primarily include cycloamanides, borosins, and dikaritins.
  • Recent advancements in bioinformatics and genome-guided discovery methods promise to enhance the identification of novel bioactive fungal RiPPs by integrating knowledge of biosynthetic pathways with gene-editing technologies.
View Article and Find Full Text PDF

Seven new nitrogen-containing heptacyclic oligophenalenone dimers, talauromides A-G (-), together with known compounds bacillisporins A and B ( and ), talaromycesones C and B ( and ), duclauxin () and lamellicolic anhydride (), were isolated from the soil derived-fungus BMC-16. Their chemical structures were determined based on spectroscopic analysis data. The absolute configurations were elucidated by chemical approaches and the comparison of CD spectra with related compounds.

View Article and Find Full Text PDF

About 20% of breast cancer patients are positive for HER2. The efficacy of current treatments is limited by primary and secondary resistance to trastuzumab. tRNA-derived fragments (tRFs) have shown crucial regulatory roles in various cancers.

View Article and Find Full Text PDF

The use of trastuzumab emtansine (T-DM1) has revealed significant efficacy in HER2-positive metastatic breast cancer (MBC). However, optimal therapeutic strategies following T-DM1 failure remain a subject of debate in clinical practice. In this multicenter, retrospective, real-world study, we sought to examine the effectiveness and safety of tyrosine kinase inhibitors (TKIs) as a therapeutic strategy in HER2-positive MBC who developed T-DM1 resistance.

View Article and Find Full Text PDF

Numerous clinical disorders have been linked to the etiology of dysregulated NLRP3 (NACHT, LRR, and PYD domain-containing protein 3) inflammasome activation. Despite its potential as a pharmacological target, modulation of NLRP3 activity remains challenging. Only a sparse number of compounds have been reported that can modulate NLRP3 and none of them have been developed into a commercially available drug.

View Article and Find Full Text PDF

Dimeric indole-containing diketopiperazines (di-DKPs) are a diverse group of natural products produced through cytochrome P450-catalyzed C-C or C-N coupling reactions. The regio- and stereoselectivity of these reactions plays a significant role in the structural diversity of di-DKPs. Despite their pivotal role, the mechanisms governing the selectivity in fungi are not fully understood.

View Article and Find Full Text PDF

Macins are a family of antimicrobial peptides, which play multiple roles in the elimination of invading pathogens. In the present study, a macin was cloned and characterized from Pacific abalone Haliotis discus hannai (Designated as HdMac). Analysis of the conserved domain suggested that HdMac was a new member of the macin family.

View Article and Find Full Text PDF

Background: Human epidermal growth factor receptor 2 (HER2)-targeted agents have significantly improved the outcomes of patients with HER2-positive breast cancer; however, a large proportion of patients still develop resistance to trastuzumab. In this study, we investigated the efficacy and safety of inetetamab, another anti-HER2 antibody, combined with pyrotinib and oral vinorelbine in patients with HER2-positive advanced breast cancer so as to provide new ideas for the treatment.

Methods: In this prospective, single-arm, phase 2 trial, patients with HER2-positive advanced breast cancer with disease progression after trastuzumab were recruited.

View Article and Find Full Text PDF

Granzyme B (GrB) is a serine protease released by natural killer cells and cytotoxic T lymphocytes during immune responses, which not only plays a role in tumor diagnosis but also provides valuable guidance during tumor treatment. In this work, we have designed a charge-switching peptide to fabricate an electrochemical biosensor for quantitative analysis of GrB. Specifically, the designed zwitterionic peptide is in an electrically neutral state before activation, and a door lock structure (proline) is constructed by utilizing the selectivity of carboxypeptidase A (CPA) to the carboxy-terminus of the peptide chain.

View Article and Find Full Text PDF

Purpose: To describe a rare case of Epstein-Barr virus (EBV)-positive primary vitreoretinal lymphoma in an immunosuppressed patient.

Methods: Observational case report.

Results: A 64-year-old man under immunosuppressive therapy for rheumatic arthritis was referred for 2 months of blurred vision and decreased visual acuity in the right eye.

View Article and Find Full Text PDF

Harmful cyanobacterial blooms have caused numerous biosecurity incidents owing to the production of hazardous secondary metabolites such as microcystin. Additionally, cyanobacteria also release many other components that have not been explored. We identified compounds of a toxic mixture exudated from a dominant, blooming species, Microcystis aeruginosa, and found that phytosphingosine (PHS) was one of the bioactive components.

View Article and Find Full Text PDF

Transfer of CeO engineered nanoparticles (NPs) through feces was investigated between two omnivorous organisms, red crucian carp (Carassius auratus red var.) and crayfish (Procambarus clarkii). Upon water exposure (5 mg/L, 7 days), the highest bioaccumulation was observed in carp gills (5.

View Article and Find Full Text PDF

Tamoxifen resistance remains a challenge in hormone receptor-positive (HR+) breast cancer. Recent evidence suggests that transfer ribonucleic acid (tRNA)-derived fragments play pivotal roles in the occurrence and development of various tumors. However, the relationship between tRNA-derived fragments and tamoxifen resistance remains unclear.

View Article and Find Full Text PDF

Lectins are a superfamily of carbohydrate-recognition proteins that bind to specific carbohydrate structures and play significant roles in immune recognition and clearance of invaders. In the study, we investigated the potential mechanisms of PAMP binding and opsonic activities of a c-type lectin and a sialic acid-binding lectin from manila clam Venerupis philippinarum (designed as VpCTL and VpSABL). Both recombinant proteins (rVpCTL and rVpSABL) could bind LPS, PGN, glucan and zymosan in vitro.

View Article and Find Full Text PDF

Genome mining of cryptic natural products (NPs) remains challenging, especially in filamentous fungi, owing to their complex genetic regulation. Increasing evidence indicates that several epigenetic modifications often act cooperatively to control fungal gene transcription, yet the ability to predictably manipulate multiple genes simultaneously is still largely limited. Here, we developed a multiplex base-editing (MBE) platform that significantly improves the capability and throughput of fungal genome manipulation, leading to the simultaneous inactivation of up to eight genes using a single transformation.

View Article and Find Full Text PDF

The mechanism(s) of immune checkpoint inhibitor (ICI)-induced myasthenia gravis (MG), an immune-related adverse event (irAE) that is fatal and limits subsequent ICI use, remain unexplored. Here, through comparative genomic analysis, we identified a pathogenic p.S467C germline variant in in a thymoma case with ICI-induced MG, which was found to be associated with fatty acid oxidation through its regulation on L-carnitine levels.

View Article and Find Full Text PDF

Cyanobacterial blooms, usually dominated by Microcystis aeruginosa, pose a serious threat to global freshwater ecosystems owing to their production and release of various harmful secondary metabolites. Detection of the chemicals in M. aeruginosa exudates using metabolomics technology revealed that phytosphingosine (PHS) was one of the most abundant compounds.

View Article and Find Full Text PDF

Background: With increased survival in breast cancer, resulting from advances in treatment, patients incur the possibility of subsequent primary malignancies, especially lung cancer. The aim of this study was to assess the frequency of CT-detected pulmonary ground-glass nodules and lung cancer following breast cancer diagnosis, the associations between breast cancer and lung cancer, the pathological features of double primary cancer, and the status of epidermal growth factor receptor (EGFR) mutations in second primary lung cancer.

Methods: Clinical data from more than 9000 individuals who were diagnosed with primary breast cancer at Jiangsu Province Hospital (Jiangsu, China) between January 2008 and December 2021 were retrospectively analyzed.

View Article and Find Full Text PDF

Release of toxic cyanobacterial secondary metabolites threatens biosecurity, foodwebs and public health. Microcystis aeruginosa (Ma), the dominant species in global freshwater cyanobacterial blooms, produces exudates (MaE) that cause adverse outcomes including nerve damage. Previously, we identified > 300 chemicals in MaE.

View Article and Find Full Text PDF

Treatment options for human epidermal growth factor receptor (HER2)-negative breast cancer patients are limited in comparison to the HER2-positive patients, particularly for metastatic breast cancer patients. Apatinib is a small-molecule tyrosine kinase inhibitor that targets the vascular endothelial growth factor receptor 2 (VEGFR-2). Here, we reported the apatinib-based therapy data in HER2-negative metastatic breast cancer.

View Article and Find Full Text PDF

The Wnt/β-catenin signaling pathway is an evolutionarily conserved signaling cascade involved in a broad range of biological roles. Dysregulation of the Wnt/β-catenin pathway is implicated in congenital malformations and various kinds of cancers. We discovered a novel Wnt/β-catenin inhibitor, talaverrucin A (), featuring an unprecedented 6/6/6/5/5/5/6 fused ring system, from an Antarctica sponge-derived fungus sp.

View Article and Find Full Text PDF

Background: Hemangioblastoma (HB) is a rare and highly vascularized tumor that originates from the central nervous system as well as other part of the body. They can appear sporadically or as part of von Hippel-Lindau (VHL) disease, a rare hereditary cancer syndrome. Although surgery can cure the majority of HBs, the disease shows a treatment-refractory challenge upon recurrence.

View Article and Find Full Text PDF

As a key regulator of the DNA translesion synthesis (TLS) pathway, RAD18 is error-prone and contributes to the accumulation of DNA mutations. Our previous study showed that it plays an essential role in the progression of multiple tumors. However, the mechanism through which RAD18 influences triple-negative breast cancer (TNBC), especially the interaction between tumor cells and the tumor microenvironment, remains elusive.

View Article and Find Full Text PDF