Abstract |
Previous studies have shown that CpG oligodeoxynucleotides (ODNs) have substantial immunostimulatory effects with anticancer applications. The antitumor applications that have been described previously are mediated through the CpG-induced activation of the host immune system, not through direct antitumor effects. Using cytostasis and cell proliferation assays, we demonstrated that specific ODNs inhibit the proliferation of RM-1 cells, a murine prostate cancer cell line. Flow cytometry analysis using propidium iodide (PI) nuclear staining confirmed the direct proapoptotic effect of ODNs on prostate cancer cells. This effect was dose dependent. Further studies using Western blot analysis and electrophoresis mobility shift assay (EMSA) revealed that the treatment of prostate cancer cells with specific ODNs activated the caspase pathway(s) and decreased the binding activities of AP-1 and NF-kappaB in a time-dependent manner. Evaluation of a panel of ODNs containing different DNA motifs demonstrated that the optimal proapoptotic sequences required polyG sequences but that CpG motifs were not essential. Finally, in vivo antitumor studies showed that the proapoptotic polyG motifs significantly inhibited prostate tumor growth. PolyG motifs inhibited tumor growth, and the effects were enhanced by CpG immune activating sequences. ODN containing both polyG and CpG motifs may have enhanced efficacy in tumor therapy through multiple mechanisms of action, including direct antitumor activities and immune activation.
|
Authors | Weiyin Shen, Marianella Waldschmidt, Xiuqin Zhao, Timothy Ratliff, Arthur M Krieg |
Journal | Antisense & nucleic acid drug development
(Antisense Nucleic Acid Drug Dev)
Vol. 12
Issue 3
Pg. 155-64
(Jun 2002)
ISSN: 1087-2906 [Print] United States |
PMID | 12162698
(Publication Type: Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)
|
Chemical References |
- NF-kappa B
- Oligodeoxyribonucleotides
- Transcription Factor AP-1
- Poly G
- Caspases
|
Topics |
- Animals
- Apoptosis
(drug effects)
- Base Sequence
- Blotting, Western
- Caspases
(metabolism)
- Cell Division
(drug effects)
- CpG Islands
- Electrophoretic Mobility Shift Assay
- Enzyme Activation
- Flow Cytometry
- Male
- Mice
- NF-kappa B
(metabolism)
- Oligodeoxyribonucleotides
(pharmacology)
- Poly G
(chemistry)
- Prostatic Neoplasms
(enzymology, metabolism, pathology)
- Protein Binding
- Transcription Factor AP-1
(metabolism)
- Tumor Cells, Cultured
|