Circulating Neutrophils Predict Poor Survival for HCC and Promote HCC Progression Through p53 and STAT3 Signaling Pathway

Background: Tumor-associated neutrophils (TANs) contribute to tumor progression, invasion, and angiogenesis. However, most studies focus on tumor infiltration neutrophils while the roles of circulating neutrophils in tumor progression remain unclear. This study was aimed to verify the pro-tumor effects of circulating neutrophils and its' mechanism in HCC. Methods: We collected clinical data of 127 HCC patients underwent TACE. The prognostic factors for overall survival (OS) were analyzed by Kaplan-Meier curve and COX models. Circulating neutrophils of HCC patients were sorted and co-cultured with human HCC cell lines MHCC-97H and SMMC-7721. Then we detected tumor cells' proliferation, migration, and invasion. Phosphokinase array was used to determine the kinase profile on MHCC-97H and SMMC-7721 cultured with or without circulating neutrophils. Results: The result of multivariate analyses of 127 patients showed that increased circulating neutrophils was an independent poor prognostic factor for OS of HCC patients underwent TACE. Circulating neutrophils promoted migration and invasion of HCC cell lines but had no impact on proliferation. The kinase profile on HCC cell lines showed that p-p53^S46 and p-STAT3^Y705 were up-regulated after co-cultured with circulating neutrophils. Repeated scratch tests and transwell tests showed a reversed impact on migration and invasion of circulating neutrophils after we treated HCC cell lines with inhibitors of p53 or STAT3. Conclusion: Circulating neutrophils was an independent poor prognostic factor for OS of HCC patients underwent TACE. It had pro-tumor effect on HCC through p53 and STAT3 signaling pathway.