Intra-platelet serotonin and YAP contributed to poor prognosis of hepatocellular carcinoma

Aims Intra-platelet 5-HT (IP 5-HT) and YAP exhibit an important role in hepatocellular carcinoma (HCC). The aim of the study was to investigate whether IP 5-HT and YAP could affect the progression and prognosis of HCC. Methods 5-HT level and YAP expression were measured and were compared between HCC patients and control patients. By grouping HCC patients, we analyzed clinical indicators and survival. The predictive nomogram was established by R software according to the risk factors obtained from multivariate analysis. Results Higher IP 5-HT level and higher YAP expression were associated with poorer prognosis. In addition, they were also associated with BCLC stages. Higher IP 5-HT was found to be related with higher international normalized ratio (INR) (p = 0.040), more death (p = 0.015) and higher YAP expression (p < 0.001). Similarly, higher YAP expression was proved to be associated with lower platelet counts (PLT) (p = 0.032), smaller tumor size (p = 0.017), more death (p < 0.001) and higher IP 5-HT (p < 0.001). In addition, alkaline phosphatase (ALP), YAP and tumor size were proved to be independent risk factors. By using risk factors, we have established a prognostic prediction nomogram for HCC patients. In the prognostic prediction nomogram, patients with higher scores would have poorer prognosis. Conclusions IP 5-HT and YAP might affect the progression and prognosis of HCC through synergistic effect. Moreover, IP 5-HT might affect HCC by regulating YAP expression. Thus, both of them might be potential therapeutic targets. By establishing the prognostic prediction nomogram, we could improve the prediction system.