Related Experiment Video
Updated: May 20, 2026
Combination Radiotherapy in an Orthotopic Mouse Brain Tumor Model
Published on: March 6, 2012
Distribution and radiosensitizing effect of cholesterol-coupled Dbait molecule in rat model of glioblastoma
Nicolas Coquery1, Nicolas Pannetier, Régine Farion
1Inserm, U836, Grenoble, France. nicolas.coquery@ujf-grenoble.fr
Background:
Glioma is the most aggressive tumor of the brain and the most efficient treatments are based on radiotherapy. However, tumors are often resistant to radiotherapy due to an enhanced DNA repair activity. Short and stabilized DNA molecules (Dbait) have recently been proposed as an efficient strategy to inhibit DNA repair in tumor.
Methodology/Principal Findings:
The distribution of three formulations of Dbait, (i) Dbait alone, (ii) Dbait associated with polyethylenimine, and (iii) Dbait linked with cholesterol (coDbait), was evaluated one day after intratumoral delivery in an RG2 rat glioma model. Dbait molecule distribution was assessed in the whole organ with 2D-FRI and in brain sections. CoDbait was chosen for further studies given its good retention in the brain, cellular localization, and efficacy in inducing the activation of DNA repair effectors. The radiosensitizing effect of coDbait was studied in four groups of rats bearing RG2-glioma: no treatment, radiotherapy only, coDbait alone, and CoDbait with radiotherapy. Treatment started 7 days after tumor inoculation and consisted of two series of treatment in two weeks: coDbait injection followed by a selective 6-Gy irradiation of the head. We evaluated the radiosensitizing effect using animal survival, tumor volume, cell proliferation, and vasculature characteristics with multiparametric MRI. CoDbait with radiotherapy improved the survival of rats bearing RG2-glioma by reducing tumor growth and cell proliferation without altering tumor vasculature.
Conclusion/Significance:
coDbait is therefore a promising molecular therapy to sensitize glioma to radiotherapy.
Insights
Cholesterol-linked DNA repair inhibitors (coDbait) show promise in enhancing radiotherapy for aggressive brain tumors (glioma). This molecular therapy improved survival by reducing tumor growth and proliferation without affecting vasculature.
Area of Science:
- Neuro-oncology
- Molecular Therapy
- Radiosensitization
Background:
- Glioma is an aggressive brain tumor often resistant to radiotherapy due to high DNA repair.
- DNA repair inhibition is a key strategy to overcome tumor radioresistance.
Purpose of the Study:
- To evaluate cholesterol-linked DNA repair inhibitors (coDbait) as a radiosensitizer for glioma.
- To assess the efficacy of coDbait in combination with radiotherapy in a preclinical glioma model.
Main Methods:
- Three Dbait formulations were tested in an RG2 rat glioma model.
- CoDbait distribution, cellular localization, and DNA repair activation were assessed.
- The radiosensitizing effect of coDbait combined with radiotherapy was evaluated using survival, tumor volume, proliferation, and MRI.
Main Results:
- CoDbait demonstrated good brain retention and induced DNA repair effector activation.
- CoDbait combined with radiotherapy significantly improved rat survival.
- This combination therapy reduced glioma growth and cell proliferation without altering tumor vasculature.
Conclusions:
- CoDbait is a promising molecular therapy for sensitizing glioma to radiotherapy.
- CoDbait represents a novel approach to enhance brain tumor treatment outcomes.
