Functional Characterization of Suppressor of Cytokine Signalling 6 and Its Interaction with Erythropoietin Receptor in Colorectal Cancer Cells.

Background: Suppressor of Cytokine Signalling 6 (SOCS6) is a cytokine signalling suppressor that regulates receptor tyrosine kinase pathways by promoting degradation of signalling proteins, thereby controlling cell growth and survival. One of these tyrosine kinase receptors, Erythropoietin Receptor (EPOR), plays a critical role in CRC progression by enhancing tumour metabolism, angiogenesis, proliferation, and growth. This study investigates the molecular mechanisms governing SOCS6's role in CRC pathogenesis using in vitro cell models and examines its interaction with EPOR expression following gene knockdown. Methods: Bioinformatics interaction between SOCS6 and EPOR were investigated using molecular visualization. HT-29 and COLO 320DM colorectal cancer cells were transfected with SOCS6 siRNA followed by measurement of SOCS6 and EPOR expression levels by qRT-PCR. The selected knockdown concentration was used in functional assays assessing cell viability, colony formation, migration, apoptosis, and invasion. Results: Bioinformatic results showed interaction between SOCS6 and EPOR through polar bonds. Furthermore, SOCS6 silencing increased cell viability and colony formation in both cell lines and significantly enhanced migration in COLO 320DM cells. Active caspase-3 levels were elevated markedly in HT-29 cells post SOCS6 knockdown, consistent with caspase-3's reported oncogenic role in CRC. Moreover, EPOR knockdown selectively altered SOCS6 expression in HT-29 cells, indicating a regulatory feedback loop. EPOR silencing elevated cell viability at 24 h in both cell lines but caused a significant decrease in COLO 320DM cells at 72 h. Conclusions: These findings identify the SOCS6-EPOR axis as a potential target for personalized CRC therapy, supporting SOCS6's tumour-suppressive and diagnostic roles.