摘要：

The Tyro3, Axl and Mer (TAM) receptor tyrosine kinases are activated by endogenous ligands, protein S1 (PROS1) and growth arrest-specific gene 6 (Gas6), and those have important effects on cell biology. These receptors (Rs) can be shad from the cell membrane and their soluble(s) forms can be found in plasma. We investigated the fluctuation and interactive role of sTAMRs and its ligands in patients with hepatocellular carcinoma (HCC), hepatitis groups, and healthy normal adult controls (NC). The measurement cases were 45 patients with HCC group (stage 1 in 4, stage 2 in 8, stage 3 in 16, and stage 4 in 17), 4 patients with fulminant hepatitis (FH), 14 patients with acute hepatitis (AH), 10 patients with chronic hepatitis (CH), 16 patients with liver cirrhosis (LC), and 20 NCs matched by age. Plasma levels of three sTAMRs and their ligands were measured by ELISA. In comparison with NCs, Gas6, des-γ-carboxy Gas6, and sTAMRs levels were significantly higher in HCC patients, but free PROS1 levels were significantly lower. The sTyro3 and sAxl levels peaked HCC stages 2 and 3 respectively, and gradually decreased afterwards while maintaining high levels. sMer levels increased with the progression of HCC. Gas6 and des-γ-carboxy Gas6 levels gradually increased, and PROS1 levels decreased with the progression of HCC. Gas6 levels were positively correlated with sAxl levels, whereas sMer levels were negatively correlated with free PROS1 levels. sTAMRs and Gas6 levels increased in parallel to the progression of HCC fibrosis. Through the progression of HCC, Axl played the major role in TAMRs activation. However, sTYro3 continued increasing rapidly from the early stage, and that of Mer increased throughout the progression. Roles of Axl may be changed in Mer, because des-γ-carboxy Gas6 levels increasing with Gas6 in the advanced stage of HCC cannot send a signal to Axl.

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