Sorafenib induced alteration of protein glycosylation in hepatocellular carcinoma cells

Abstract

Sorafenib is a multikinase inhibitor and is effec-tive in treating hepatocellular carcinoma (HCC). However, it remains unknown whether sorafenib induces the altera-tion of protein glycosylation. The present study treated HCC MHCC97L and MHCC97H cells with a 50% inhibi-tory concentration of sorafenib. Following this treatment, alteration of protein glycosylation was detected using a lectin microarray. Compared with the controls, the binding capacity of glycoproteins extracted from sorafenib-treated HCC cells to the lectins Bauhinia purpurea lectin, Dolichos biflorus agglutinin, Euonymus europaeus lectin, Helix aspersa lectin, Helix pomatia lectin, Jacalin, Maclura pomifera lectin and Vicia villosa lectin were enhanced; while, the binding capacities to the lectins Caragana arborescens lectin, Lyco- persicon esculentum lectin, Limulus polyphemus lectin, Maackia amurensis lecin I, Phaseolus vulgaris leucoag-glutinin, Ricinus communis agglutinin 60, Sambucus nigra lectin and Solanum tuberosum lectin were reduced (spot intensity median/background intensity median ≥2, P<0.05). This difference in glycoprotein binding capacity indicates that cells treated with sorafenib could increase α-1,3GalNAc/ Gal, β-1,3 Gal, GalNAcα-Ser/Thr(Tn) and α-GalNAc structures and decrease GlcNAc, sialic acid, tetra-antennary complex-type N-glycan and β-1,4Gal structures. These results were additionally confirmed by lectin blotting. Expression levels of signaling molecules including erythroblastosis 26-1 (Ets-1), extracellular signal-related kinases (ERK) and phos-phorylated-ERK were measured by western blotting. There was a reduction in the expression of Ets-1 and ERK phos-phorylation in sorafenib or 1,4-Diamino-2,3-dicyano-1,4-bis (2-aminophenylthio) butadiene treated cells suggesting that sorafenib may reduce the expression levels of Ets-1 by blocking the Ras/Raf/mitogen activated protein kinase signaling pathway. In the present study, it was clear that sorafenib could inhibit the proliferation of HCC cells and alter protein glycosylation. The findings of this study may lead to providing a novel way of designing new anti-HCC drugs.