TC_phosphoproteomic

<p>The aim of this study was to characterize proteomic and phosphoproteomic alterations in testicular cancer, focusing on two major histopathological subtypes: seminoma and non-seminoma. The analysis also aimed to assess the impact of protein phosphorylation changes between tumor and matched control tissue, as well as between tumor subtypes, on cellular homeostasis and dysregulated biochemical processes potentially associated with early metastatic behavior.</p><p>Tumor and matched control tissues were collected from 46 patients undergoing orchiectomy at the Department of Urology, Medical University of Białystok. Tumor samples were obtained directly from the tumor mass, while control tissue was collected from the contralateral pole of the same testis. Proteomic and phosphoproteomic analyses were performed using an Orbitrap Astral mass spectrometer coupled with nano-flow liquid chromatography. Phosphopeptide enrichment was conducted using Ti IMAC HP and Zn IMAC HP magnetic beads. Data were acquired in Data Independent Acquisition (DIA) mode.</p><p>Global proteomic profiling identified approximately 7,500 proteins, including around 2,500 proteins significantly differentiating tumor tissue from control tissue and approximately 1,800 proteins distinguishing seminoma from non-seminoma. Phosphoproteomic analysis enabled the identification of approximately 3,500 phosphorylated proteins.</p><p>Seminomas were characterized by increased expression of proteins involved in antigen processing and presentation, DNA replication and repair, ribosome biogenesis, cell cycle progression, protein synthesis and folding, and mitochondrial translation. In contrast, seminomas exhibited reduced activity of glutathione metabolism, fatty acid oxidation, and cholesterol biosynthesis. Non-seminomatous tumors displayed enhanced activation of extracellular matrix organization, collagen synthesis, cytoskeletal remodeling, cell adhesion, migration, complement system activation, and endoplasmic reticulum stress response. Although both tumor subtypes showed decreased glutathione metabolism relative to control tissue, non-seminomas demonstrated higher glutathione-related activity compared to seminomas.</p><p>These findings provide comprehensive insights into subtype-specific molecular mechanisms of testicular cancer and identify biological processes potentially contributing to tumor progression and early metastasis.</p>