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


CONCLUSIONS
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.
Deacon
Donna H
DH
Department of Surgery, University of Virginia, Charlottesville, VA 22908, USA. dmh9q@virginia.edu
Hogan
Kevin T
KT
Swanson
Erin M
EM
Chianese-Bullock
Kimberly A
KA
Denlinger
Chadrick E
CE
Czarkowski
Andrea R
AR
Schrecengost
Randy S
RS
Patterson
James W
JW
Teague
Mark W
MW
Slingluff
Craig L
CL
D017209:Apoptosis / Q000528:radiation effects; D015153:Blotting, Western; D019496:Cancer Vaccines; D049109:Cell Proliferation / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006801:Humans; D007150:Immunohistochemistry; D008545:Melanoma / Q000628:therapy*; D014407:Tumor Cells, Cultured / Q000528:radiation effects*; D014466:Ultraviolet Rays
D019496:Cancer Vaccines