Time-series clustering of cytokine expression after transarterial chemoembolization in patients with hepatocellular carcinoma

Cytokines play an important role in the development of tumors. The purpose of the present study was to evaluate the mechanisms and cytokine level changes after transarterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC). The Short Time-series Expression Miner (STEM) program was utilized to cluster cytokine expression profiles from the day before TACE to day 21 post-TACE. Based on the identified significant signatures, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed. Cytokines were serially monitored in 60 evaluable patients to identify the results of the STEM program. Examination of the significant signatures identified 6 significant time-varied expression patterns for 507 cytokines (profiles 16, 18, 28, 41, 42 and 43). GO analysis was enriched in ‘cytokine receptor-binding’ and ‘cytokine receptor activity’, and the identified signaling pathways included ‘cytokine-cytokine receptor interaction’ and the ‘JAK-STAT signaling pathway’. Ciliary neurotrophic factor (CNTF) level was increased early after TACE, reaching a peak on day 7 before finally decreasing from day 14 onwards, and was significantly positively correlated with aminotransferase level. Serum levels of pre-TACE IL-10 predicted the local tumor response and overall survival (OS) of the patients, while serum levels of post-TACE IL-1β only indicated the local tumor response of the patient. Overall, the present study identified cytokine time-series expression profiles of patients with HCC undergoing TACE. Early phase increases in CNTF after TACE were associated with post-treatment hepatic injury. IL-1β may reflect an objective response after TACE, while IL-10 may represent a biomarker for OS and the objective response pre-TACE, which may help patients with HCC to benefit from TACE.