Effects of direct injection of dehydrated ethanol on PC3 human prostate cancer cells in nude mice: Preliminary study

The effect of direct local injection of dehydrated ethanol on hormone-independent prostatic carcinoma cells (PC3 cells) implanted in nude mice was investigated.PC3 tumors were implanted subcutaneously into 30 nude mice. Three weeks later, dehydrated ethanol was injected directly into the tumors. Twenty-three animals received an injection of ethanol at a volume of 40 microL, 80 microL, or 160 microL, and were divided into a low-dose group (n = 11) and a high-dose group (n = 12) on the basis of the ethanol/tumor volume ratio (<30% versus> or =30%). The control group (n = 7) was injected with 40 microL of physiological saline. The tumor volume before treatment was 324.9 +/- 110.9 mm(3) and was assessed as well as 1 day, 4 days, 1 week, 2 weeks, and 3 weeks after injection. Then the changes of tumor volume were compared between the two ethanol groups (low-dose group and high-dose group) and the control group. Histological examination was performed for up to 3 weeks after injection.Assessment of tumor volume showed that the ethanol/tumor volume ratio was 16.1 +/- 5.3% in the low-dose group (n = 5) and 51.8 +/- 20.3% in the high-dose group (n = 6). Tumor growth was significantly inhibited after 1 and 2 weeks in the ethanol groups compared with the control group (n = 3). After 3 weeks, there was a tendency for tumor regrowth in the low-dose group, but growth inhibition was maintained in the high-dose group. Histological examination showed tumor degeneration and necrosis with feeding vessel obstruction in the acute phase.Local injection of dehydrated ethanol regressed tumors of prostatic carcinoma cells in nude mice, with the degeneration of tumor cells and occlusion of feeding vessels.