TY - JOUR
T1 - Bortezomib sensitizes HCC cells to CS-1008, an antihuman death receptor 5 antibody, through the inhibition of CIP2A
AU - Chen, Kuen Feng
AU - Yu, Hui Chuan
AU - Liu, Chun Yu
AU - Chen, Hui Ju
AU - Chen, Yi Ching
AU - Hou, Duen Ren
AU - Chen, Pei Jer
AU - Cheng, Ann Lii
PY - 2011/5
Y1 - 2011/5
N2 - Previously, we have shown that bortezomib overcame TRAIL resistance in hepatocellular carcinoma (HCC) cells via the inhibition of Akt. Here, we report that bortezomib sensitizes these TRAIL-resistant cells, including Huh-7, Hep3B, and Sk-Hep1, to CS-1008, a humanized agonistic antihuman death receptor 5 antibody. Cancerous inhibitor of protein phosphatase 2A (CIP2A) mediated the sensitizing effect of bortezomib to CS-1008 through inhibiting protein phosphatase 2A (PP2A) activity. Combination treatment of bortezomib and CS-1008 downregulated CIP2A in a concentration- and time-dependent manner, and increased PP2A activity in HCC cells. Importantly, ectopic expression of CIP2A decreased Akt-related PP2A activity, indicating that CIP2A negatively regulates Akt-related PP2A activity in HCC cells. Moreover, silencing CIP2A by short interfering RNA enhanced CS-1008-induced apoptosis in HCC cells and ectopic expression of CIP2A in HCC cells abolished CS-1008-induced apoptosis, indicating that CIP2A plays an important role in the sensitizing effect of bortezomib to CS-1008. Finally, our in vivo data showed that CS-1008 and bortezomib combination treatment decreased tumor growth significantly. In conclusion, bortezomib sensitized HCC cells to CS-1008 through the inhibition of CIP2A.
AB - Previously, we have shown that bortezomib overcame TRAIL resistance in hepatocellular carcinoma (HCC) cells via the inhibition of Akt. Here, we report that bortezomib sensitizes these TRAIL-resistant cells, including Huh-7, Hep3B, and Sk-Hep1, to CS-1008, a humanized agonistic antihuman death receptor 5 antibody. Cancerous inhibitor of protein phosphatase 2A (CIP2A) mediated the sensitizing effect of bortezomib to CS-1008 through inhibiting protein phosphatase 2A (PP2A) activity. Combination treatment of bortezomib and CS-1008 downregulated CIP2A in a concentration- and time-dependent manner, and increased PP2A activity in HCC cells. Importantly, ectopic expression of CIP2A decreased Akt-related PP2A activity, indicating that CIP2A negatively regulates Akt-related PP2A activity in HCC cells. Moreover, silencing CIP2A by short interfering RNA enhanced CS-1008-induced apoptosis in HCC cells and ectopic expression of CIP2A in HCC cells abolished CS-1008-induced apoptosis, indicating that CIP2A plays an important role in the sensitizing effect of bortezomib to CS-1008. Finally, our in vivo data showed that CS-1008 and bortezomib combination treatment decreased tumor growth significantly. In conclusion, bortezomib sensitized HCC cells to CS-1008 through the inhibition of CIP2A.
UR - http://www.scopus.com/inward/record.url?scp=84984548924&partnerID=8YFLogxK
U2 - 10.1158/1535-7163.MCT-10-0794
DO - 10.1158/1535-7163.MCT-10-0794
M3 - 期刊論文
AN - SCOPUS:84984548924
SN - 1535-7163
VL - 10
SP - 892
EP - 901
JO - Molecular Cancer Therapeutics
JF - Molecular Cancer Therapeutics
IS - 5
ER -