Biomedical subjects

Yi Shi

Publications and source records attributed to Yi Shi.

4 recordsLinked to original sources

PubMed2026

Molecular differences between poorly and well/moderately differentiated lung adenocarcinoma and their clinical implications.

BACKGROUND: Diagnostic and therapeutic techniques for lung adenocarcinoma (LUAD) have advanced rapidly. However, the morphology-based assessment of tumor differentiation commonly used in clinical practice has several limitations, including strong subjectivity, inability to reflect tumor heterogeneity, and limited prognostic predictive value. This study aimed to identify key genetic mutations associated with tumor differentiation features and explored their potential clinical impact of these molecular features on tumor prognosis and therapeutic response. METHODS: In this study, 196 LUAD tissue samples collected from Fujian Cancer Hospital between 2021 and 2023 were analyzed using integrated high-throughput sequencing and comprehensive bioinformatics approaches. Molecular differences between poorly differentiated tumors and moderately/well-differentiated tumors were characterized. The effects of these molecular alterations on tumor behavior and therapeutic response were examined, with the aim of exploring biomarkers associated with poor prognosis and treatment in LUAD. RESULTS: Our findings showed a significant quantitative difference in tumor mutation burden, EGFR co-mutations, patterns of co-occurrence resulting in distinct clinical outcomes. Among these alterations, mutations in LRP1B and TP53, as well as EGFR amplification, MET amplification, JAK2 deletion and CDKN2B deletion were significantly enriched in the poorly differentiated group, whereas EGFR mutations were significantly enriched in the moderately/well-differentiated group. We also identified MET amplification and LRP1B mutation as independent poor prognostic factors in LUAD. Moreover, a subset of poorly differentiated group exhibited DNA double-strand breaks possibly due to homologous recombination deficiency (HRD), along with frequent alterations of immune evasion-related genes. CONCLUSIONS: These findings provide novel insights into the molecular basis of LUAD and the development of novel targeted differentiation-related therapies and precision genome-guided treatments.

Lung adenocarcinoma (LUAD)↗

PubMed2026

Chromatin Remodeling Subunit ARID1A Negatively Regulates the Malignant Progression of Gastrointestinal Stromal Tumors by Targeting the MEMO1 Promoter.

Gastrointestinal stromal tumors (GISTs) are the most common sarcomas of the alimentary tract and are primarily characterized by malignant progression, a major cause of mortality. AT-rich interaction domain 1A (ARID1A), a core component of the chromatin-remodeling SWI/SNF complex, has been found to correlate with GIST tumor grade, although the underlying mechanism remains unclear. Its frequent inactivation across diverse cancer types reveals pleiotropic roles that intersect multiple hallmarks of cancer. In this study, we aimed to investigate the potential relationship between ARID1A and malignant progression in GISTs, as well as the underlying mechanism. Western blotting, real-time polymerase chain reaction, and immunohistochemistry were used to assess ARID1A expression in GIST tissues. Cell Counting Kit-8 (CCK-8) assays were performed to evaluate cell proliferation. Wound-healing and Transwell assays were conducted to assess cell migration and invasion. Flow cytometry was used to analyze apoptosis and cell cycle distribution. Label-free quantitative proteomics and chromatin immunoprecipitation sequencing (ChIP-seq) were employed to identify top candidate downstream targets of ARID1A. ARID1A expression was decreased in high-risk GIST tissues. Furthermore, ARID1A knockdown in GIST cells promoted proliferation and metastasis both in vitro and in vivo, and led to reduced apoptosis and impaired cell cycle arrest. We further demonstrated that ARID1A suppresses GIST proliferation and metastasis by inhibiting MEMO1 expression and inactivating the ERK1/2 signaling pathway. Notably, this regulatory axis was observed in KIT-null GIST cells, indicating that the ARID1A-MEMO1 pathway may function independently of canonical KIT signaling. Thus, ARID1A inhibits malignant progression in GISTs, providing new insights into its role in the prevention and treatment of human GISTs and suggesting its potential as a biomarker of malignant progression in GISTs.

Humans↗

PubMed2025

One thousand SARS-CoV-2 antibody structures reveal convergent binding and near-universal immune escape.

Understanding antibody recognition and adaptation to viral evolution is central to vaccine and therapeutic development. Over 1,100 SARS-CoV-2 antibody structures have been resolved, marking the largest structural biology effort for a single pathogen. We present a comprehensive analysis of this landmark dataset to investigate the principles of antibody recognition and immune escape. Human immunoglobulins and camelid single-chain antibodies dominate, collectively mapping 99% of the receptor-binding domain. Despite remarkable sequence and conformational diversity, antibodies exhibit convergence in their paratope structures, revealing evolutionary constraints in epitope selection. Analyses reveal near-universal immune escape of antibodies, including all clinical monoclonals, by advanced variants such as KP3.1.1. On average, over one-third of antibody epitope residues are mutated. These findings support pervasive immune escape, underscoring the need to effectively leverage multi-epitope-targeting strategies to achieve durable immunity. To support community accessibility, we developed an interactive web server for visualization and analysis of antibody-antigen complexes and mutational data.

SARS-CoV-2↗

PubMed2024

NS2 induces an influenza A RNA polymerase hexamer and acts as a transcription to replication switch.

Genome transcription and replication of influenza A virus (FluA), catalyzed by viral RNA polymerase (FluAPol), are delicately controlled across the virus life cycle. A switch from transcription to replication occurring at later stage of an infection is critical for progeny virion production and viral non-structural protein NS2 has been implicated in regulating the switch. However, the underlying regulatory mechanisms and the structure of NS2 remained elusive for years. Here, we determine the cryo-EM structure of the FluAPol-NS2 complex at ~3.0 Å resolution. Surprisingly, three domain-swapped NS2 dimers arrange three symmetrical FluPol dimers into a highly ordered barrel-like hexamer. Further structural and functional analyses demonstrate that NS2 binding not only hampers the interaction between FluAPol and the Pol II CTD because of steric conflicts, but also impairs FluAPol transcriptase activity by stalling it in the replicase conformation. Moreover, this is the first visualization of the full-length NS2 structure. Our findings uncover key molecular mechanisms of the FluA transcription-replication switch and have implications for the development of antivirals.

Viral Nonstructural Proteins↗