RT Journal Article T1 In-depth quantitative proteomics analysis revealed C1GALT1 depletion in ECC-1 cells mimics an aggressive endometrial cancer phenotype observed in cancer patients with low C1GALT1 expression A1 Montero Calle, Ana A1 López Janeiro, Álvaro A1 Mendes, Marta L. A1 Pérez Hernández, Daniel A1 Echevarría, Irene A1 Ruz Caracuel, Ignacio A1 Heredia soto, Victoria A1 Mendiola, Marta A1 Hardisson, David A1 Argüeso, Pablo A1 Peláez García, Alberto, Alberto A1 Guzmán Aránguez, Ana Isabel A1 Barderas Manchado, Rodrigo AB Background: Endometrial cancer (EC) is the most common cancer of the female reproductive organs. Despite the good overall prognosis of most low-grade ECs, FIGO I and FIGO II patients might experience tumor recurrence and worse prognosis. The study of alterations related to EC pathogenesis might help to get insights into underlying mechanisms involved in EC development and progression.Methods: Core tumoral samples were used to investigate the role of C1GALT1 in EC by immunohistochemistry (IHC). ECC-1 cells were used as endometrioid EC model to investigate the effect of C1GALT1 depletion using C1GALT1 specific shRNAs. SILAC quantitative proteomics analyses and cell-based assays, PCR, qPCR, WB, dot-blot and IHC analyses were used to identify, quantify and validate dysregulation of proteins.Results: Low C1GALT1 protein expression levels associate to a more aggressive phenotype of EC. Out of 5208 proteins identified and quantified by LC-MS/MS, 100 proteins showed dysregulation (log2fold-change ≥ 0.58 or ≤-0.58) in the cell protein extracts and 144 in the secretome of C1GALT1 depleted ECC-1 cells. Nine dysregulated proteins were validated. Bioinformatics analyses pointed out to an increase in pathways associated with an aggressive phenotype. This finding was corroborated by loss-of-function cell-based assays demonstrating higher proliferation, invasion, migration, colony formation and angiogenesis capacity in C1GALT1 depleted cells. These effects were associated to the overexpression of ANXA1, as demonstrated by ANXA1 transient silencing cell-based assays, and thus, correlating C1GALT and ANXA1 protein expression and biological effects. Finally, the negative protein expression correlation found by proteomics between C1GALT1 and LGALS3 was confirmed by IHC.Conclusion: C1GALT1 stably depleted ECC-1 cells mimic an EC aggressive phenotype observed in patients and might be useful for the identification and validation of EC markers of progression. PB Springer Nature SN 2211-3428; 2211-3436 (E-ISSN) YR 2023 FD 2023-02-06 LK https://hdl.handle.net/20.500.14352/72981 UL https://hdl.handle.net/20.500.14352/72981 LA eng NO Acuerdo Transformativo CRUE-CSICAccepted: 19 January 2023; Published: 06 February 2023 NO Fondos FEDER - Programa AES-ISCIII NO Ministerio de Educación, Cultura y Deporte de España DS Docta Complutense RD 10 abr 2025