Can TIE-2 expressing monocytes represent a novel marker for hepatocellular carcinoma?

Hepatocellular carcinoma (HCC), the predominant form of primary liver cancer, is a globalhealth problem representing the sixth most common cancer and the third cause of cancer related deathworldwide. The number of deaths per year in HCC is comparable to the incidence number, underlyingthe aggressive behavior of HCC and the modest efficacy of available curative treatments. Effective HCCtreatment is problematic also due to the lack of early and specific diagnostic markers. In this regard,particular interest has been put on the tyrosine kinase with Ig and endothelial growth factor (EGF)homology domains 2 (TIE2), a receptor of angiopoietins, predominantly present on endothelial cells butalso observed on monocytes [TIE-2-expressing monocytes (TEMs)]. Recently, a work by Matsubara et al.showed that the amount of circulating TEMs is higher in hepatitis virus C (HCV)/HCC patients comparedto HCV patients or healthy subjects. Additionally the authors showed that TEMs have a diagnostic potentialfor HCC. Whereas the molecular mechanisms responsible for this observation remain elusive and furtherstudies are necessary to confirm this finding, the work of Matsubara et al. may contribute to the identificationof a novel HCC prognostic and diagnostic marker.