Significant antitumoral activity of cationic multilamellar liposomes containing human IFN-beta gene against human renal cell carcinoma.
OBJECTIVE
Immunotherapy is the most effective treatment against metastatic renal cell carcinoma (RCC). However, the response rate is approximately 15%. More effective therapy is, therefore, needed for patients with metastatic RCC. We then examined the antitumor effect of cationic multilamellar liposome containing human IFN-beta (huIFN-beta) gene (IAB-1) against RCC.


METHODS
Concentrations of huIFN-beta protein were measured by ELISA. The cytotoxicity of IAB-1 against human RCC (NC65, ACHN, and freshly isolated RCC cells), prostate and bladder cancer cell lines, and renal proximal tubule endothelial cells (RPTEC5899) was examined by the colorimetric method using tetrazolium salt. Apoptosis was assessed by the acridine-orange staining. For in vivo study, we used NC65 cells inoculated into severe combined immunodeficiency mouse.


RESULTS
The RCC cells treated with IAB-1 secreted significant amounts of huIFN-beta protein continuously. Drastic in vitro cytotoxic effect of IAB-1 against RCC was observed. In contrast, treatment with 1000 IU/ml recombinant huIFN-beta protein resulted in weak cytotoxicity. The cytotoxic effect against prostate and bladder cancer cell lines was less than that against RCC. Furthermore, no significant cytotoxicity was observed in RPTEC5899 cells. Apoptosis was observed in the cells treated with IAB-1, but recombinant huIFN-beta failed to induce apoptosis. The size of NC65 tumors transfected with IAB-1 in mice was significantly smaller than that receiving injection of empty liposome or recombinant huIFN-beta protein.


CONCLUSIONS
These findings indicate that IAB-1 may have an antitumor activity against human RCC by inducing apoptosis, suggesting its potential clinical application for gene therapy against RCC.
Nakanishi
Hiroyuki
H
Department of Urology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan.
Mizutani
Yoichi
Y
Kawauchi
Akihiro
A
Ukimura
Osamu
O
Shiraishi
Takumi
T
Hatano
Manabu
M
Mizuno
Masaaki
M
Yoshida
Jun
J
Miki
Tsuneharu
T
D000165:Acridine Orange / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis; D002292:Carcinoma, Renal Cell / Q000473:pathology / Q000628:therapy*; D002412:Cations; D004396:Coloring Agents / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods; D006801:Humans; D007167:Immunotherapy / Q000379:methods*; D016899:Interferon-beta / Q000235:genetics* / Q000627:therapeutic use*; D007680:Kidney Neoplasms / Q000473:pathology / Q000628:therapy*; D007700:Kinetics; D008081:Liposomes / Q000737:chemistry*; D051379:Mice; D016513:Mice, SCID; D008856:Microscopy, Fluorescence; D011994:Recombinant Proteins / Q000378:metabolism; D013997:Time Factors; D014162:Transfection; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D002412:Cations; D004396:Coloring Agents; D008081:Liposomes; D011994:Recombinant Proteins; D016899:Interferon-beta; D000165:Acridine Orange