Liposome-mediated in vivo gene transfer of antisense K-ras construct inhibits pancreatic tumor dissemination in the murine peritoneal cavity.
K-ras point mutation occurs at a characteristically high incidence in human pancreatic cancer. Plasmids expressing antisense (AS), AS-K-ras-LNSX or sense K-ras gene fragment, were first transduced into three human pancreatic cancer cell lines (AsPC-1, MIAPaCa-2, and BxPC-3) by liposome-mediated transfection. A stable expression of antisense or sense K-ras RNA was detected by Northern blot analysis, and Western blot analysis confirmed a reduction of up to 20% of K-ras-specific p21 protein in AsPC-1 cells transduced with AS-K-ras-LNSX. The growth of pancreatic cancer cells with K-ras point mutations (AsPC-1 and MIAPaCa-2) was significantly suppressed after transduction of AS-K-ras-LNSX, although the effect of antisense construct was not found in cells with a wild-type K-ras gene (BxPC-3). Next, to test the efficacy in vivo, AsPC-1 cells were inoculated into the intraperitoneal cavity of nude mice, and 3 days later, the AS-K-ras-LNSX:liposome complex was injected i.p. 3 times. Twenty-eight days after tumor cell inoculation, 9 of 10 control mice developed peritoneal dissemination and/or solid tumors on the pancreas, whereas only 2 of 12 mice treated with AS-K-ras-LNSX showed any evidence of tumors. Although PCR analysis indicated that the injected DNA was delivered to various organs except for the brain, treatment-related toxicity was not observed. This study shows that the liposome-mediated in vivo gene transfer of antisense K-ras construct may be a useful therapeutic strategy for pancreatic cancer.
Aoki
K
K
Genetics Division, National Cancer Center Research Institute, Tokyo, Japan.
Yoshida
T
T
Sugimura
T
T
Terada
M
M
D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000378:metabolism*; D004247:DNA / Q000008:administration & dosage / Q000032:analysis / Q000627:therapeutic use*; D018014:Gene Transfer Techniques; D011905:Genes, ras / Q000235:genetics*; D005822:Genetic Vectors; D006801:Humans; D008081:Liposomes; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008969:Molecular Sequence Data; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000473:pathology / Q000517:prevention & control*; D010534:Peritoneal Neoplasms / Q000517:prevention & control*; D016133:Polymerase Chain Reaction; D016372:RNA, Antisense / Q000032:analysis / Q000378:metabolism*; D014407:Tumor Cells, Cultured
C493956:CDKN1A protein, human; C493957:Cdkn1a protein, mouse; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D008081:Liposomes; D016372:RNA, Antisense; D004247:DNA