SUMO1 promotes malignancy and chemoresistance in colorectal cancer: Clinical and functional evidence.

Colorectal cancer (CRC) patients often experience poor prognosis due to chemoresistance development, prompting investigation into the role of SUMO1 in CRC malignancy and treatment resistance. We initially analyzed tumor and adjacent normal tissues from 50 CRC patients to compare expression levels of key SUMOylation molecules SUMO1 and SUMO2, then expanded our cohort to 328 CRC cases to evaluate SUMO1 expression and clinical significance. Stable SUMO1 overexpression and knockdown cell lines were established for comprehensive functional assays, including CCK-8, colony formation, Transwell migration, wound healing, and cell cycle analyses. Tumor proliferation was further assessed using subcutaneous xenograft mouse models, and SUMO1 effects on oxaliplatin resistance were evaluated both in vitro and in vivo. Clinical analysis of 328 CRC patients revealed SUMO1 overexpression in tumor tissues, which correlated with worse patient prognosis. Functional studies confirmed that SUMO1 significantly promoted CRC cell proliferation, colony formation, migration, invasion, and cell cycle progression in both laboratory and animal models. Importantly, SUMO1 enhanced chemoresistance to oxaliplatin and drove overall CRC progression. These findings demonstrate that SUMO1 serves as an independent prognostic indicator for CRC patients, with its expression promoting malignant cellular phenotypes and conferring oxaliplatin resistance both in vitro and in vivo. This research provides valuable new insights for potential therapeutic targeting in CRC treatment strategies.