Tumor tissue was homogenized by the use of a homogenizer
at 4°C in buffer (30 mM NaHCO3, pH 7.1) with freshly added protease inhibitor phenyl-methylsulfonyl fluoride (0.5 mM). The homogenate was centrifuged at 10,000 g for 30 min at 4°C and the supernatant was then centrifuged at 100,000 g at 4°C for 2 h. The resulting supernatant was dialyzed against 20 mM Tris-HCl and 150 mM NaCl, pH 7.2, and then was applied to Sephacryl S-200HR. Bovine serum albumin was used as a molecular indicator in a pilot experiment to map Caspase Inhibitor VI the range of eluted fractions. The tumor supernatant protein was eluted with the same sample loading buffer. The collected fractions of eluted protein underwent SDS-PAGE. The fractions of #3 to #6 contained proteins of about 40-200 kDa. The combination of these 4 fractions was used as the mHSP/Ps vaccine. The identity of proteins in this combination was assayed using SDS-PAGE and Western blot analysis with antibodies specific to various HSPs. In vivo antitumor experiments To evaluate the antitumor activity of the mHSP/Ps preparation, mice were divided into 6 groups for GSK1210151A cell line treatment (n = 10 mice each): 1) normal saline control, 2) ACP-196 chemical structure mHSP/Ps, 3) CY plus IL-12, 4) mHSP/Ps plus IL-12,
5) mHSP/Ps plus CY, 6) mHSP/Ps plus Cy plus IL-12. All mice were subcutaneously injected in the back with 5 × 104 S180 cells. One day later, groups Groups 2, 4, 5, and 6 mice were vaccinated 3 times at 7-day intervals with 20 μg of mHSP/Ps. Groups 5 and 6 received 2
mg of CY intraperitoneally 1 day after the last vaccination. Groups 4 and 6 mice were subcutaneously Leukotriene-A4 hydrolase injected with IL-12, 100 ng/day, for 5 days, 3 days after a CY injection. Group 3 mice received CY plus IL-12 at the same time as Group 6, but the treatment started on day 16. The antitumor effects were evaluated by tumor volume, tumor growth inhibition rates, metastasis rate and overall survival time. Tumor volume was determined by the measurement of the shortest (A) and longest diameter (B) using a caliper once every 3 days. The volume (V) was calculated by the formula V = (A2B/2). Curative survival was considered to occur when the tumor did not regrow or disappeared after more than 3 months. Lungs, liver and brains of dead mice were removed and fixed in formalin, embedded in paraffin, and sectioned at 5 μm. Hematoxylin & eosin (H&E) stained samples were examined under a light microscope (Olympus). Analysis of immune response Treatment of mice for analysis of immune responses was the same as that for immunotherapy. Three days after the combined therapy of mHSP/Ps and CY plus IL-12, all mice were killed, and blood and spleen samples were collected. Mice from various control groups were killed at the same time.