Objectives. Recent studies show that prostate adenocarcinoma cells can
survive cryosurgery and that cell destruction depends on the specific
thermal parameters used during freezing. The goal of this preliminary
study is to determine whether certain chemical compounds, known as an
tifreeze proteins, can induce com-; plete human primary prostatic aden
ocarcinoma cell destruction by freezing, regardless of the thermal par
ameters used. The study also examines the mechanism by which antifreez
e proteins bring about cell destruction. Methods. Antifreeze proteins
were added to solutions containing human primary prostatic adenocarcin
oma cells. The cells were frozen with controlled thermal parameters us
ing a directional solidification apparatus attached to a light microsc
ope. Cell viability was determined after thawing as a function of anti
freeze protein concentration and cooling rate during freezing. Results
. The dose response study shows that for all the cooling rates tested,
10-mg/mL solutions of antifreeze protein cause the complete destructi
on of human primary prostatic adenocarcinoma cells frozen to a tempera
ture at which, without these proteins, the cells survive freezing. Lig
ht microscopy shows that the lethal effect of the antifreeze proteins
is related to the formation of intracellular ice in the frozen cells.
Conclusions. This preliminary study has demonstrated that antifreeze p
roteins have the ability to generate complete destruction of prostatic
adenocarcinoma cells frozen to high subzero temperatures irrespective
of the cooling rates used during freezing. This suggests that introdu
cing antifreeze proteins into undesirable tissues prior to freezing ma
y increase the efficacy and the control over tissue destruction by cry
osurgery. (C) 1997, Elsevier Science Inc.