Research article

The use of gamma-irradiation and ultraviolet-irradiation in the preparation of human melanoma cells for use in autologous whole-cell vaccines

Donna H Deacon^1,2 , Kevin T Hogan^1,2 , Erin M Swanson¹ , Kimberly A Chianese-Bullock^1,2 , Chadrick E Denlinger¹ , Andrea R Czarkowski¹ , Randy S Schrecengost¹ , James W Patterson³ , Mark W Teague³ and Craig L Slingluff Jr^1,2

¹Department of Surgery, University of Virginia, Charlottesville, VA, 22908, USA

²Human Immune Therapy Center, University of Virginia, Charlottesville, VA, 22908, USA

³Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA

author email corresponding author email

BMC Cancer 2008, 8:360doi:10.1186/1471-2407-8-360

Published:	4 December 2008

Abstract

Background

Human cancer vaccines incorporating autologous tumor cells carry a risk of implantation and subsequent metastasis of viable tumor cells into the patient who is being treated. Despite the fact that the melanoma cell preparations used in a recent vaccine trial (Mel37) were gamma-irradiated (200 Gy), approximately 25% of the preparations failed quality control release criteria which required that the irradiated cells incorporate ³H-thymidine at no more than 5% the level seen in the non-irradiated cells. We have, therefore, investigated ultraviolet (UV)-irradiation as a possible adjunct to, or replacement for gamma-irradiation.

Methods

Melanoma cells were gamma- and/or UV-irradiated. ³H-thymidine uptake was used to assess proliferation of the treated and untreated cells. Caspase-3 activity and DNA fragmentation were measured as indicators of apoptosis. Immunohistochemistry and Western blot analysis was used to assess antigen expression.

Results

UV-irradiation, either alone or in combination with gamma-irradiation, proved to be extremely effective in controlling the proliferation of melanoma cells. In contrast to gamma-irradiation, UV-irradiation was also capable of inducing significant levels of apoptosis. UV-irradiation, but not gamma-irradiation, was associated with the loss of tyrosinase expression. Neither form of radiation affected the expression of gp100, MART-1/MelanA, or S100.

Conclusion

These results indicate that UV-irradiation may increase the safety of autologous melanoma vaccines, although it may do so at the expense of altering the antigenic profile of the irradiated tumor cells.