Highlights d Discovery of prognosis-associated proteins and pathways at early stage of LUAD d Proteomics revealed three subtypes related to clinical and molecular features d Identification of subtype-specific kinases and cancerassociated phosphoproteins d Identification of potential prognostic biomarkers and drug targets in LUAD
The diffuse-type gastric cancer (DGC) is a subtype of gastric cancer with the worst prognosis and few treatment options. Here we present a dataset from 84 DGC patients, composed of a proteome of 11,340 gene products and mutation information of 274 cancer driver genes covering paired tumor and nearby tissue. DGC can be classified into three subtypes (PX1–3) based on the altered proteome alone. PX1 and PX2 exhibit dysregulation in the cell cycle and PX2 features an additional EMT process; PX3 is enriched in immune response proteins, has the worst survival, and is insensitive to chemotherapy. Data analysis revealed four major vulnerabilities in DGC that may be targeted for treatment, and allowed the nomination of potential immunotherapy targets for DGC patients, particularly for those in PX3. This dataset provides a rich resource for information and knowledge mining toward altered signaling pathways in DGC and demonstrates the benefit of proteomic analysis in cancer molecular subtyping.
Replication of nuclear DNA occurs in the context of chromatin and is influenced by histone modifications. In the ciliate Tetrahymena thermophila, we identified TXR1, encoding a histone methyltransferase. TXR1 deletion resulted in severe DNA replication stress, manifested by the accumulation of ssDNA, production of aberrant replication intermediates, and activation of robust DNA damage responses. Paired-end Illumina sequencing of ssDNA revealed intergenic regions, including replication origins, as hot spots for replication stress in DTXR1 cells. DTXR1 cells showed a deficiency in histone H3 Lys 27 monomethylation (H3K27me1), while DEZL2 cells, deleting a Drosophila E(z) homolog, were deficient in H3K27 di-and trimethylation, with no detectable replication stress. A point mutation in histone H3 at Lys 27 (H3 K27Q) mirrored the phenotype of DTXR1, corroborating H3K27me1 as a key player in DNA replication. Additionally, we demonstrated interactions between TXR1 and proliferating cell nuclear antigen (PCNA). These findings support a conserved pathway through which H3K27me1 facilitates replication elongation.
In order to reveal the mechanisms of the extreme radioresistance and DNA repair in Deinococcus radiodurans, we examined proteome changes in a wild-type strain following gamma-irradiation using two-dimensional polyacrylamide gel electrophoresis and Silver-staining. The expression levels of 26 protein spots showed significant changes under radiation stress. Of these spots, 21 were identified with peptide mass fingerprinting using matrix-assisted laser desorption/ionization-time of flight mass spectrometry after tryptic in-gel digestion. These proteins exhibited various cellular functions, including (i) translation; (ii) transcription; (iii) signal transduction; (iv) post-translational modification, protein turnover, chaperones; (v) carbohydrate transport and metabolism; (vi) energy production and conversion; (vii) nucleotide transport and metabolism; (viii) inorganic ion transport and metabolism; (ix) DNA replication, recombination and repair; and (x) yet unknown. Most of the proteins have not previously been reported to be relevant to radioresistance.
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