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Systemic delivery of siRNA specific to tumor mediated by atelocollagen: Combined therapy using siRNA targeting Bcl‐xL and cisplatin against prostate cancer
Author(s) -
Mu Ping,
Nagahara Shunji,
Makita Naoki,
Tarumi Yuzo,
Kadomatsu Kenji,
Takei Yoshifumi
Publication year - 2009
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.24382
Subject(s) - small interfering rna , apoptosis , cancer research , bcl xl , cisplatin , systemic administration , prostate cancer , medicine , prostate , cancer , cell culture , transfection , in vivo , programmed cell death , chemistry , biology , chemotherapy , biochemistry , genetics , microbiology and biotechnology
The largest obstacle to the effective use of short interfering RNA (siRNA) in an animal body is the ability to deliver it to the target tissue. Here we showed a systemic delivery method of siRNA specific to pregrown solid tumors via atelocollagen. Atelocollagen facilitated the selective uptake of siRNA into the tumors when an siRNA/atelocollagen complex was administered intravenously to mice. We chose a Bcl‐xL protein as a model target to prove the therapeutic efficacy of the atelocollagen‐mediated method. Bcl‐xL acts as an anti‐apoptotic factor, which is overexpressed in many cancers, including prostate cancer. One of the four designed siRNAs to human Bcl‐xL potently inhibited the expression of Bcl‐xL by the PC‐3 human prostate cancer cell line in vitro , leading to cell apoptosis. Intravenous injections for3 consecutive days (siRNA, 100 μg/injection per day as a complex with atelocollagen) effectively downregulated Bcl‐xL expression in the PC‐3 xenograft. We administered four series of 3 consecutive days of intravenous injections each, for a total of 12 injections, which significantly inhibited tumor growth when the treatment was combined with cisplatin (2 mg/kg). Local injection of Bcl‐xL siRNA also potently inhibited tumor growth. All of the tumors treated with Bcl‐xL siRNA/atelocollagen complex via both intravenous and intratumoral injection showed terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labeling‐positive apoptosis. There were no severe side effects such as interferon‐α induction and liver or renal damage in mice. Our results indicate that systemic delivery of siRNA via atelocollagen, which specifically targets tumors, is safe and feasible for cancer therapy. © 2009 UICC