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Nucleolar and nuclear aberrations in human lox tumor cells following treatment with p120 antisense oligonucleotide
L Perlaky1, K Smetana, R K Busch
1Department of Pharmacology, Baylor College of Medicine, Houston, TX 77030.
Abstract:
Previous reports from this laboratory have shown marked cytocidal effects of the ISIS-3466 antisense phosphorothioate oligodeoxynucleotide to the human nucleolar protein p120 on human cancer cell lines in vitro and inhibition of tumor growth in vivo in an i.p/i.p. LOX cell model (L. Perlaky et al. Anti-Cancer Drug Design 8:3-14, 1993). In this study, light and fluorescence microscopy showed that the number of LOX cells in mitosis decreased by 50% after incubation for 4 h in 0.2-0.4 microM antisense oligonucleotide; a 70% reduction in cell number was found from 8-72 h post-treatment. In addition, marked unravelling of nucleolar structures and chromatin fragmentation was found after a 4-h incubation. The nucleolar unravelling occurred in varying degrees ranging from partial unfolding to almost complete separation of the strands of nucleolar residues. Twenty four hours post-treatment, immunofluorescence staining with the anti-p120 monoclonal antibody showed reduced nucleolar protein p120 and translocation of the p120 protein from the nucleoli to the nucleoplasm. Analysis of the mechanisms of the nucleolar unravelling and inhibition of mitosis will provide further understanding of the cytocidal effects of the ISIS-3466 antisense oligonucleotide.
Insights
The ISIS-3466 antisense oligonucleotide significantly reduces cancer cell mitosis and number by disrupting nucleolar structures and protein p120. This study details its cytocidal effects on LOX cancer cells.
Area of Science:
- Molecular Biology
- Cancer Research
- Antisense Technology
Background:
- Previous studies demonstrated the cytocidal effects of ISIS-3466 antisense phosphorothioate oligodeoxynucleotide against human cancer cell lines.
- ISIS-3466 targets the human nucleolar protein p120, showing potential for cancer treatment.
Purpose of the Study:
- To investigate the effects of ISIS-3466 on LOX cancer cells, focusing on mitosis and nucleolar structure.
- To analyze the impact of ISIS-3466 on nucleolar protein p120 localization and cellular morphology.
Main Methods:
- Light and fluorescence microscopy were used to observe changes in LOX cells.
- Immunofluorescence staining with anti-p120 monoclonal antibody assessed protein levels and localization.
- Cell counts and morphological changes were quantified over time post-treatment.
Main Results:
- A 50% decrease in mitosis was observed within 4 hours of incubation with 0.2-0.4 microM ISIS-3466.
- A 70% reduction in cell number occurred 8-72 hours post-treatment.
- Marked nucleolar unravelling, chromatin fragmentation, and p120 protein translocation from nucleoli to nucleoplasm were observed.
Conclusions:
- ISIS-3466 effectively inhibits cancer cell proliferation and induces cell death.
- The observed nucleolar disruption and p120 protein translocation are key mechanisms underlying the cytocidal effects.
- Further research into these mechanisms can enhance the therapeutic potential of antisense oligonucleotides.
