GRP78 and GAL3, differentially regulated by lymph node homogenates, as potential biomarkers for lymph node metastasis in mouse hepatocellular carcinoma cells.

In order to systematically evaluate the influence of lymph nodes (LNs) in lymph node metastases (LNM) of hepatocellular carcinoma (HCC), we set up a new in vitro model in which Hca-F and Hca-P cells were cultured in medium containing lymph node homogenates (LNHs). Differential protein expression was measured by two-dimensional gel electrophoresis (2-DE) combined with matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI TOF/TOF MS). Results from protein identification revealed two metastatic correlative proteins, 78-kDa glucose-regulated protein (GRP78) and galectin-3 (GAL3). Western blotting confirmed that GRP78, a protein positively correlated with metastasis, increased 2.4-fold in Hca-F cells but decreased to almost a half in Hca-P cells (P<0.05). However, GAL3, a protein negatively correlated with metastasis, was decreased by a half in Hca-F cells but slightly increased non-significantly in Hca-P cells. Thus, our results reveal that some components of LNHs may facilitate a permissive environment for cancer cells with high metastasis potential to eventually metastasize. GRP78 and GAL3 may serve as potential biomarkers for the diagnosis of LNM in HCC.