TY - JOUR
T1 - Autocrine vascular endothelial growth factor signaling promotes cell proliferation and modulates sorafenib treatment efficacy in hepatocellular carcinoma
AU - Peng, Sui
AU - Wang, Ye
AU - Peng, Hong
AU - Chen, Dong
AU - Shen, Shunli
AU - Peng, Baogang
AU - Chen, Minhu
AU - Lencioni, Riccardo
AU - Kuang, Ming
N1 - Publisher Copyright:
© 2014 by the American Association for the Study of Liver Diseases.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2014/10/1
Y1 - 2014/10/1
N2 - Tumor cells express vascular endothelial growth factor (VEGF) that can activate VEGF receptors (VEGFRs) on or within tumor cells to promote growth in an angiogenesis-independent fashion; however, this autocrine VEGF pathway has not been reported in hepatocellular carcinoma (HCC). Sorafenib, an angiogenic inhibitor, is the only drug approved for use in advanced HCC patients. Yet the treatment efficacy is diverse and the mechanism behind it remains undetermined. Our aims were to study the molecular mechanisms underlying autocrine VEGF signaling in HCC cells and evaluate the critical role of autocrine VEGF signaling on sorafenib treatment efficacy. By immunohistochemistry, we found robust nuclear and cytoplasmic staining for active, phosphorylated VEGF receptor 1 (pVEGFR1) and phosphorylated VEGF receptor 2 (pVEGFR2), and by western blotting we found that membrane VEGFR1 and VEGFR2 increased in HCC tissues. We showed that autocrine VEGF promoted phosphorylation of VEGFR1 and VEGFR2 and internalization of pVEGFR2 in HCC cells, which was both pro-proliferative through a protein lipase C-extracellular kinase pathway and self-sustaining through increasing VEGF, VEGFR1, and VEGFR2 mRNA expressions. In high VEGFR1/2-expressing HepG2 cells, sorafenib treatment inhibited cell proliferation, reduced VEGFR2 mRNA expression in vitro, and delayed xenograft tumor growth in vivo. These results were not found in low VEGFR1/2-expressing Hep3B cells. In an advanced HCC population on sorafenib treatment for postoperative recurrence, we found that the absence of VEGFR1 or VEGFR2 expression in resected tumor tissues before sorafenib treatment was associated with poorer overall survival. Conclusion: Autocrine VEGF signaling directly promotes HCC cell proliferation and affects the sorafenib treatment outcome in vitro and in vivo, which may enable better stratification for clinical treatment decisions. (Hepatology 2014;60:1264-1277).
AB - Tumor cells express vascular endothelial growth factor (VEGF) that can activate VEGF receptors (VEGFRs) on or within tumor cells to promote growth in an angiogenesis-independent fashion; however, this autocrine VEGF pathway has not been reported in hepatocellular carcinoma (HCC). Sorafenib, an angiogenic inhibitor, is the only drug approved for use in advanced HCC patients. Yet the treatment efficacy is diverse and the mechanism behind it remains undetermined. Our aims were to study the molecular mechanisms underlying autocrine VEGF signaling in HCC cells and evaluate the critical role of autocrine VEGF signaling on sorafenib treatment efficacy. By immunohistochemistry, we found robust nuclear and cytoplasmic staining for active, phosphorylated VEGF receptor 1 (pVEGFR1) and phosphorylated VEGF receptor 2 (pVEGFR2), and by western blotting we found that membrane VEGFR1 and VEGFR2 increased in HCC tissues. We showed that autocrine VEGF promoted phosphorylation of VEGFR1 and VEGFR2 and internalization of pVEGFR2 in HCC cells, which was both pro-proliferative through a protein lipase C-extracellular kinase pathway and self-sustaining through increasing VEGF, VEGFR1, and VEGFR2 mRNA expressions. In high VEGFR1/2-expressing HepG2 cells, sorafenib treatment inhibited cell proliferation, reduced VEGFR2 mRNA expression in vitro, and delayed xenograft tumor growth in vivo. These results were not found in low VEGFR1/2-expressing Hep3B cells. In an advanced HCC population on sorafenib treatment for postoperative recurrence, we found that the absence of VEGFR1 or VEGFR2 expression in resected tumor tissues before sorafenib treatment was associated with poorer overall survival. Conclusion: Autocrine VEGF signaling directly promotes HCC cell proliferation and affects the sorafenib treatment outcome in vitro and in vivo, which may enable better stratification for clinical treatment decisions. (Hepatology 2014;60:1264-1277).
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U2 - 10.1002/hep.27236
DO - 10.1002/hep.27236
M3 - Article
C2 - 24849467
AN - SCOPUS:84919479359
VL - 60
SP - 1264
EP - 1277
JO - Hepatology
JF - Hepatology
SN - 0270-9139
IS - 4
ER -