Improved anti-cancer effect of interferon gene transfer by sustained expression using CpG-reduced plasmid DNA.
Plasmid DNA (pDNA) expressing mouse interferon (IFN)-beta or IFN-gamma (pCMV-Mu beta and pCMV-Mu gamma, respectively) has been shown to be effective in inhibiting the growth of colon carcinoma CT-26 cells in the liver (Kobayashi et al., Molecular Therapy 2002;6:737-44). The therapeutic effect of such IFN gene transfer could be significantly increased by the sustained expression of IFNs. In the present study, CpG-reduced pDNA encoding IFN-beta or IFN-gamma (pGZB-Mu beta and pGZB-Mu gamma, respectively) was constructed. pCMV-Mu beta and pCMV-Mu gamma were used as conventional CpG-replete pDNAs. Each pDNA was injected into the tail vein of mice by the hydrodynamics-based procedure. An injection of pGZB-Mu beta resulted in very high IFN-beta activities in the serum for at least 24 hr after injection, whereas the IFN-beta activity after pCMV-Mu beta injection declined quickly. About a 14-fold greater amount of IFN-beta was produced from pGZB-Mu beta than from pCMV-Mu beta. pGZB-Mu beta markedly inhibited the pulmonary metastasis of CT-26 cells. Similar, but more marked results were obtained with pGZB-Mu gamma: it increased the area under the concentration-time curve by more than a 60-fold and the mean residence time of IFN-gamma 4-fold compared with pCMV-Mu gamma. The survival time of the pGZB-Mu gamma-treated mice was significantly (p<0.05) longer than that of the saline- or pCMV-Mu gamma-treated mice. These results indicate that long-term expression of IFN can be achieved by CpG-reduced pDNA and sustained IFN gene expression results in enhanced therapeutic effects of IFN gene transfer against tumor metastasis.
Kawano
Hiroki
H
Department of Biopharmaceutics and Drug Metabolism, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan.
Nishikawa
Makiya
M
Mitsui
Masaru
M
Takahashi
Yuki
Y
Kako
Keiko
K
Yamaoka
Kiyoshi
K
Watanabe
Yoshihiko
Y
Takakura
Yoshinobu
Y
D000818:Animals; D019540:Area Under Curve; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D018899:CpG Islands / Q000235:genetics*; D015870:Gene Expression; D015316:Genetic Therapy / Q000379:methods*; D007275:Injections, Intravenous; D007371:Interferon-gamma / Q000097:blood / Q000235:genetics* / Q000378:metabolism; D008175:Lung Neoplasms / Q000517:prevention & control / Q000556:secondary; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D010957:Plasmids / Q000008:administration & dosage / Q000235:genetics* / Q000493:pharmacokinetics; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome
D007371:Interferon-gamma