Figure 6.

CDK inhibitor treatment of human melanoma xenograft-bearing nude mice. (A) Representative, individual examples of the growth rate of subcutaneous WM983-B MGP melanoma xenografts in nude mice that received the first i.p. injection of the CDK inhibitor (40 mg/kg) (CDKI; light blue-colored line; dark blue-colored line); CDK inhibitor (CDKI) (40 mg/kg) followed 24 hr later by i.p. injection of Paclitaxel (10 mg/kg) (CDKI/Paclitaxel: green-colored line); or only the CDK inhibitor delivery vehicle DMSO (DMSO: black-colored line), on the day (Day 1) a tumor had reached 5 mm in any direction. Subsequent i.p. injections were given on Day 3, 7 and 10. Following the last i.p. injections on Day 10 (indicated by the triangle), tumor volumes in these animals were further recorded on Day 14, 17, 21 and 24. The red-colored line depicts the growth rate of a WM983-B MGP melanoma xenograft in an animal that had been treated i.p. with 40 mg/kg of the CDK inhibitor on Day 1, 3, 7, 10, 14 and 17. (B) CDK2 and CDK5 immunohistochemical analysis of tissue sections prepared from WM983-B MGP melanoma xenografts that until Day 10 had been injected with only DMSO or only Paclitaxel, the CDK inhibitor (CDKI), or the CDK inhibitor combined with Paclitaxel (CDKI/Paclitaxel). Images of the fluorescent DAPI-stained or hematoxylin-counterstained and CDK2 or CDK5-stained tumor sections are depicted at 40X and 20X magnification, respectively.