Inhibition of cell proliferation in HCC-9204 hepatoma cells by a c-myc specific ribozyme.
A ribozyme (RZ) gene targeting c-myc mRNA was synthesized and cloned. Cleavage reaction showed that cleavage of the RZ was efficient and specific. The RZ gene-containing retrovirus vector pDOR-RZ was transfected into HCC-9204 hepatoma cells, which constitutively express high levels of c-myc using Lipofectamine. Positively transfected cells were selected using G418. In situ hybridization showed that both pDOR-RZ and pDOR vectors had been integrated into the chromosome of HCC-9204 cells. Dot blot hybridization indicated that expression of the RZ was only evident in pDOR-RZ-transfected HCC-9204 cells. Avidin-biotin complex enzyme-linked immunosorbent assay showed that c-myc expression was down-regulated. Chromatin aggregation into compact masses, cytoplasmic vacuole degeneration, and blurring of cytoplasm structure were observed by transmission electron microscopy in HCC-9204-RZ cells. These results suggest that the use of a c-myc mRNA cleaving enzyme could be most effective in tumor cells that are highly proliferative and constitutively express high levels of c-myc.
Cheng
J
J
Department of Pharmacology, New York University Medical Center, New York 10016, USA.
Luo
J
J
Zhang
X
X
Hu
J
J
Hui
H
H
Wang
C
C
Stern
A
A
D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000378:metabolism / Q000473:pathology* / Q000628:therapy*; D005822:Genetic Vectors / Q000138:chemical synthesis / Q000378:metabolism; D006131:Growth Inhibitors / Q000235:genetics / Q000494:pharmacology*; D006801:Humans; D006868:Hydrolysis; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology* / Q000628:therapy*; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics*; D016337:RNA, Catalytic / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D006131:Growth Inhibitors; D016271:Proto-Oncogene Proteins c-myc; D016337:RNA, Catalytic