OBJECTIVES: Cullin family genes play a critical role in ubiquitin-mediated protein degradation and have been implicated in various cancers. However, their expression patterns, prognostic significance, and functional roles in rectal adenocarcinoma (READ) remain unclear. This study aims to comprehensively analyze the expression, prognostic value, and potential biological functions of culllin genes in READ. METHODS: We analyzed the transcriptional expression of CUL1, CUL2, CUL3, CUL4A, CUL4B, CUL5, CUL7, and CUL9 in READ using publicly available databases, including UALCAN and HOA. The prognostic significance of CUL genes was evaluated using Kaplan-Meier survival analysis. Functional enrichment analysis was performed to determine the biological pathways associated with cullin gene expression. Additionally, siRNA-mediated knockdown of CUL genes was done to assess the effect on cell proliferation, migration, and colony formation. RESULTS: The analysis revealed significant overexpression of cullin genes in READ compared to normal tissues. Survival analysis indicated that higher expression of specific CUL2 and CUL7 genes correlated with poor prognosis in READ patients. Functional enrichment analysis demonstrated that cullin genes were associated with diverse enrichment terms. In vitro experiments showed that siRNA-mediated knockdown of CUL2 and CUL47 led to a significant reduction in cell proliferation, migration, and colony formation, highlighting their potential oncogenic role in READ. CONCLUSION: This study provides novel insight into the role of cullin genes in READ, suggesting that CUL2 and CUL7 may be biomarkers and therapeutic targets. Further research is warranted to explore their underlying mechanisms and clinical applications in READ management.