Effects of pre-irradiation and SDF-1 suppression on the progression of murine astrocytoma cells grown in different stromal beds

Abstract

Purpose: To examine whether brain tumors grown in pre-irradiated (PreIR) thigh have a similar tumor bed effect (TBE) as in PreIR brain tissue.

Material and methods: Tumor growth delay and immunohistochemical (IHC) staining for CD31, an endothelial surface marker, and PIMO, a hypoxia marker, were used to study the TBE of a murine astrocytoma, ALTS1C1, or a stromal-derived factor-1 (SDF-1) gene-silenced astrocytoma, ALTS1C1-SDFkd, growing in different PreIR stroma beds.

Results: ALTS1C1 tumors growing in both PreIR brain and PreIR thigh had reduced microvascular density (MVD) and more chronic hypoxia, but tumor growth delay was only seen in PreIR brain tissue. In contrast, ALTS1C1-SDFkd tumors showed tumor growth delay in PreIR thigh, with little effect in PreIR brain tissue.

Conclusions: This study cautions that both the tumor and the nature of the PreIR stromal bed are important when using pre-irradiation as a model of recurrent brain tumors after radiation therapy.

Keywords::

• Glioma
• radiation therapy
• SDF-1

Acknowledgements

The authors thank Professor William H. McBride, UCLA, for helpful discussions and proofreading on this manuscript.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

This study was supported by NHRI-EX102-10132BI, NSC 101-2627-N-007-001, NTHU-102N2767E1, NHTU-102N2739E1, and NHTU-102N2051E1 grants to C.S. Chiang; CMRPD1C0641 and CMRPD1C0661 grant to F.H. Chen; NSC 100-2314-B-182A-094 grant to C.S. Tsai; NTHU-HCH100-01 to Y.C. Yang. S.C. Wang was supported by the post-doctor fellowship of National Tsing Hua University, Taiwan; C.F. Yu was supported by post-doctor fellowship of CMRPD1C0641 and CMRPD1C0661 grant, Chang Gung University, Taiwan.