FIGURE 8.

PIIBNP inhibits MDA-MB231 breast cancer tumor invasion in vitro and growth in NOD/SCID mice. A, invasion assay. MB231 breast cancer cells were allowed to invade three-dimensional matrigel-coated membranes in the presence of 5 μm GST, PIIBNP, or mPIIBNP for 30 h prior to fixation and quantification of invasion. Toluidine blue-stained cells are shown in the top panel. In the bottom panel, data are expressed as mean numbers of invading cells per high power field (20×) ± S.D. from a minimum of 12 fields/condition. Statistical significance of means was determined using Student's t test (*, p < 0.005 relative to mPIIBNP or GST control). B, in vivo tumor assay. When the tumors grew to 0.5 cm in diameter, the mice were divided into two groups with three mice in each. Mice received 6 nmol of PIIBNP or GST/mouse/day by subcutaneous injection into the tumor for 2 weeks. This experiment has been repeated with identical results. Dashed lines, circumference of the tumor. C, when the largest tumor size in the control group reached to 2 cm in diameter, the mice were sacrificed, and tumors were removed. The tumor weights were represented as mean ± S.D. (*, p < 0.01 as compared with GST control, n = 6).