TY - JOUR
T1 - Synergistic antitumor effects of combination treatment with metronomic doxorubicin and VEGF-targeting RNAi nanoparticles
AU - Kwak, Gijung
AU - Jo, Sung Duk
AU - Kim, Dongkyu
AU - Kim, Hyosuk
AU - Kim, Myung Goo
AU - Kim, Kwangmeyung
AU - Kwon, Ick Chan
AU - Kim, Sun Hwa
N1 - Funding Information:
This research was supported by Global Innovative Research Center (GiRC) Program [ NRF-2012K1A1A2A01056095 ] and Creative Materials Discovery Program [ NRF-2016M3D1A1021392 ] through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning ; and the Intramural Research Program of KIST .
Publisher Copyright:
© 2017 Elsevier B.V.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2017/12/10
Y1 - 2017/12/10
N2 - Conventional cancer treatment strategies have been aimed at eradicating all cancer cells. To this end, standard chemotherapeutic approaches have relied on the maximum tolerated dose (MTD) of cytotoxic drugs with a long off-therapy interval, leading to heavy toxic side effects accompanied by drug resistance. To avoid the problems associated with the traditional MTD chemotherapy, metronomic chemotherapy with relatively low dose continuous treatments of cytotoxic drugs has been proposed as an alternative to the predominant paradigm of directly killing all cancer cells. Low-dose metronomic (LDM) chemotherapy is expected to have not only antitumor effects without toxicity and drug resistance, but also beneficial anti-angiogenic effects by causing selective apoptosis of tumor endothelial cells. In an attempt to keep the drug resistance under control and halt exponential tumor growth, herein, we combined LDM chemotherapy with a second anti-angiogenic strategy. The selective blockade of vascular endothelial growth factor (VEGF) in combination with metronomic doxorubicin (Dox) induced synergistic antitumor effects mainly through an antiangiogenic mechanism. For specific VEGF suppression, VEGF-targeting siRNA was delivered to tumor tissue using polymerized siRNA/thiolated glycol chitosan (poly-siVEGF/tGC) nanoparticles, leading to efficient VEGF gene knockdown in tumor tissue with a sequence-specific manner. Although the single treatment with metronomic Dox and poly-siVEGF/tGC nanoparticles alone showed some antitumor activity, notably, the combination of the two therapies resulted in superb tumor regression without causing systemic toxicity or drug resistance. Thus, these results suggest that the VEGF-targeted RNAi using poly-siRNA/tGC nanoparticles in combination with LDM chemotherapy could be a promising synergistic strategy for controlling tumor growth by enhancing the efficacy of anti-angiogenesis while minimizing toxicity and drug resistance.
AB - Conventional cancer treatment strategies have been aimed at eradicating all cancer cells. To this end, standard chemotherapeutic approaches have relied on the maximum tolerated dose (MTD) of cytotoxic drugs with a long off-therapy interval, leading to heavy toxic side effects accompanied by drug resistance. To avoid the problems associated with the traditional MTD chemotherapy, metronomic chemotherapy with relatively low dose continuous treatments of cytotoxic drugs has been proposed as an alternative to the predominant paradigm of directly killing all cancer cells. Low-dose metronomic (LDM) chemotherapy is expected to have not only antitumor effects without toxicity and drug resistance, but also beneficial anti-angiogenic effects by causing selective apoptosis of tumor endothelial cells. In an attempt to keep the drug resistance under control and halt exponential tumor growth, herein, we combined LDM chemotherapy with a second anti-angiogenic strategy. The selective blockade of vascular endothelial growth factor (VEGF) in combination with metronomic doxorubicin (Dox) induced synergistic antitumor effects mainly through an antiangiogenic mechanism. For specific VEGF suppression, VEGF-targeting siRNA was delivered to tumor tissue using polymerized siRNA/thiolated glycol chitosan (poly-siVEGF/tGC) nanoparticles, leading to efficient VEGF gene knockdown in tumor tissue with a sequence-specific manner. Although the single treatment with metronomic Dox and poly-siVEGF/tGC nanoparticles alone showed some antitumor activity, notably, the combination of the two therapies resulted in superb tumor regression without causing systemic toxicity or drug resistance. Thus, these results suggest that the VEGF-targeted RNAi using poly-siRNA/tGC nanoparticles in combination with LDM chemotherapy could be a promising synergistic strategy for controlling tumor growth by enhancing the efficacy of anti-angiogenesis while minimizing toxicity and drug resistance.
KW - Anti-angiogenesis
KW - Combination therapy
KW - Drug resistance
KW - Low-dose metronomic chemotherapy
KW - VEGF
KW - siRNA
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U2 - 10.1016/j.jconrel.2017.08.015
DO - 10.1016/j.jconrel.2017.08.015
M3 - Article
C2 - 28823674
AN - SCOPUS:85028456150
VL - 267
SP - 203
EP - 213
JO - Journal of Controlled Release
JF - Journal of Controlled Release
SN - 0168-3659
ER -