Biomedical subjects

Zhi Xie

Publications and source records attributed to Zhi Xie.

3 recordsLinked to original sources

PubMed2026

Expanding the human proteome with microproteins and peptideins.

A major scientific drive is to characterize the protein-coding genome, which is a primary basis for studying human health. But the fundamental question remains of what has been missed in previous analyses. Over the past decade, the translation of non-canonical open reading frames (ncORFs) has been observed across human cell types and disease states1-3, with major implications for biomedical science. However, a key gap in knowledge has been which ncORFs produce small microproteins or alternative protein molecules that contribute to the human proteome. Here we report the collaborative efforts of the TransCODE Consortium4 to produce a consensus landscape of protein-level evidence for ncORFs. We show that about 25% of a set of 7,264 ncORFs gives rise to detectable peptides in a large-scale analysis of 95,520 proteomics experiments. We develop an annotation framework for ncORF-encoded microproteins as human proteins and codify the new conceptual model of 'peptideins' as microproteins that have indeterminate potential as functional proteins. To probe the biological implications of peptideins, we create an evolutionary analysis approach, termed ORF relative branch length (ORBL), and determine that evolutionary constraint is common and associates with observation of ncORF-derived peptides. We then characterize a pan-essential cellular phenotype for one peptidein from the OLMALINC long non-coding RNA. Overall, we generate public research tools supported by GENCODE and PeptideAtlas and advance biomedical discovery for understudied components of the human proteome.

Humans↗

PubMed2025

High-quality peptide evidence for annotating non-canonical open reading frames as human proteins.

A major scientific drive is to characterize the protein-coding genome as it provides the primary basis for the study of human health. But the fundamental question remains: what has been missed in prior genomic analyses? Over the past decade, the translation of non-canonical open reading frames (ncORFs) has been observed across human cell types and disease states, with major implications for proteomics, genomics, and clinical science. However, the impact of ncORFs has been limited by the absence of a large-scale understanding of their contribution to the human proteome. Here, we report the collaborative efforts of stakeholders in proteomics, immunopeptidomics, Ribo-seq ORF discovery, and gene annotation, to produce a consensus landscape of protein-level evidence for ncORFs. We show that at least 25% of a set of 7,264 ncORFs give rise to translated gene products, yielding over 3,000 peptides in a pan-proteome analysis encompassing 3.8 billion mass spectra from 95,520 experiments. With these data, we developed an annotation framework for ncORFs and created public tools for researchers through GENCODE and PeptideAtlas. This work will provide a platform to advance ncORF-derived proteins in biomedical discovery and, beyond humans, diverse animals and plants where ncORFs are similarly observed.

GENCODE↗

PubMed2025

Impaired natural killer cell maturation in lung adenocarcinoma driven by FABP4 and SPON2 downregulation through disrupted lipid metabolism.

BACKGROUND: Although natural killer (NK) cells play a crucial role in antitumor immunity, the metabolic changes driving their dysfunction in lung adenocarcinoma remain poorly understood. This study investigates how these metabolic modifications impact NK cell function within the lung adenocarcinoma microenvironment. METHODS: A total of 13 pairs of lung adenocarcinoma samples were obtained from The Cancer Genome Atlas. Differential gene expression, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, and single-cell metabolic quantification analyses were used to characterize the transcriptomic, pathway, and metabolic signatures of NK cells. The developmental trajectory was reconstructed via pseudotime analysis. The fatty acid-binding protein 4 (FABP4) and spondin2 (SPON2) expression was examined using immunofluorescence (IF) and immunohistochemistry (IHC) in patients with lung adenocarcinoma. In NK cells with FABP4 downregulation, FABP4 function was analyzed using antibody-independent cell-mediated cytotoxicity assays, flow cytometry (FCM), and liquid chromatography-mass spectrometry. RESULTS: The number of NK cells was significantly decreased in the lung adenocarcinoma microenvironment. FABP4 and SPON2 expression was significantly lower in NK cells within tumor tissues than in the adjacent tissues. FABP4 expression was significantly lower in tumor tissues than in the adjacent tissues, whereas no significant difference in SPON2 expression was observed. The cytotoxic function of NK cells with decreased FABP4 levels was impaired. Non-targeted lipid metabolism analysis indicated that differentially expressed lipids in NK cells with low FABP4 levels were functionally enriched in the glycerophospholipid metabolism pathway compared to those in normal NK cells. CONCLUSIONS: The study findings present new evidence showing that low FABP4 and SPON2 gene expression may impair NK cell maturity by affecting lipid metabolism in lung adenocarcinoma. These results provide a new perspective on restoring immune function in patients with lung cancer.

FABP4↗