The combination of ionizing radiation and peripheral vaccination produces long-term survival of mice bearing established invasive GL261 gliomas.

Abstract

PURPOSE:

High-grade glioma treatment includes ionizing radiation therapy. The high invasiveness of glioma cells precludes their eradication and is responsible for the dismal prognosis. Recently, we reported the down-regulation of MHC class I (MHC-I) products in invading tumor cells in human and mouse GL261 gliomas. Here, we tested the hypothesis that whole-brain radiotherapy (WBRT) up-regulates MHC-I expression on GL261 tumors and enhances the effectiveness of immunotherapy.

EXPERIMENTAL DESIGN:

MHC-I molecule expression on GL261 cells was analyzed in vitro and in vivo by flow cytometry and immunohistochemistry, respectively. To test the response of established GL261 gliomas to treatment, mice with measurable (at CT imaging) brain tumors were randomly assigned to four groups receiving (a) no treatment, (b) WBRT in two fractions of 4 Gy, (c) vaccination with irradiated GL261 cells secreting granulocyte-macrophage colony-stimulating factor, or (d) WBRT and vaccination. Endpoints were tumor response and survival.

RESULTS:

An ionizing radiation dose of 4 Gy maximally up-regulated MHC-I molecules on GL261 cells in vitro. In vivo, WBRT induced the expression of the beta2-microglobulin light chain subunit of the MHC class I complex on glioma cells invading normal brain and increased CD4+ and CD8+ T cell infiltration. However, the survival advantage obtained with WBRT or vaccination alone was minimal. In contrast, WBRT in combination with vaccination increased long-term survival to 40% to 80%, compared with 0% to 10% in the other groups (P < 0.002). Surviving animals showed antitumor immunity by rejecting challenge tumors.

CONCLUSION:

Ionizing radiation can be successfully combined with peripheral vaccination for the treatment of established high-grade gliomas.

• Authors: Elizabeth W Newcomb, Sandra Demaria, Yevgeniy Lukyanov, Yongzhao Shao, Tona Schnee, Noriko Kawashima, Li Lan, J Keith Dewyngaert, David Zagzag, William H McBride, Silvia C Formenti
• Journal: Clinical cancer research : an official journal of the American Association for Cancer Research (Clin Cancer Res) Vol. 12 Issue 15 Pg. 4730-7 (Aug 01 2006) ISSN: 1078-0432 [Print] United States
• PMID: 16899624 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Cancer Vaccines
• Histocompatibility Antigens Class I
• Immunoglobulin Light Chains
• beta 2-Microglobulin

Topics

• Animals
• Brain Neoplasms (diagnosis, immunology, therapy)
• Cancer Vaccines (therapeutic use)
• Cell Line, Tumor
• Combined Modality Therapy
• Disease Models, Animal
• Disease-Free Survival
• Dose-Response Relationship, Radiation
• Female
• Flow Cytometry
• Glioma (diagnosis, immunology, therapy)
• Histocompatibility Antigens Class I (biosynthesis, radiation effects)
• Humans
• Immunoglobulin Light Chains (biosynthesis, radiation effects)
• Immunohistochemistry
• Immunotherapy
• Mice
• Radiation, Ionizing
• Tomography, X-Ray Computed
• Transplantation, Heterologous
• Up-Regulation (radiation effects)
• Xenograft Model Antitumor Assays
• beta 2-Microglobulin (biosynthesis, radiation effects)