CC-5079: a small molecule with MKP1, antiangiogenic, and antitumor activity.

INTRODUCTION: CC-5079, a small molecule inhibitor of tubulin polymerization and phosphodiesterase-4 activity, was evaluated for antiangiogenic and antitumor activities. MATERIALS AND METHODS: First, CC-5079 in vitro activity on human umbilical vein endothelial cells (HUVECs), fibroblasts, and MC38 were evaluated by proliferation, migration, and invasion assays. Second, CC-5079 effect on microvessel formation was evaluated ex vivo by chick chorioallantoic membrane (CAM), rat aortic rings assays, and with directed in vivo angiogenesis assay (DIVAA). Third, CC-5079 antitumor effect was determined in treatment of C57BL/6 mice with MC38 tumors. Finally, CC-5079 modulation of MKP1 in HUVECs, human fibroblast, and MC38 were determined by RNA isolation for qRT-PCR. RESULTS: At the 0.1 µM concentration CC-5079 significantly inhibited HUVEC, fibroblast, and MC38 proliferation and migration (all P < 0.001). At the 0.1 µM concentration, CC-5079 also inhibited HUVEC invasion (P < 0.05) but not fibroblast. In the CAM and rat aortic ring assays, CC-5079 at 0.1 µM inhibited microvessel formation (P < 0.05). By DIVAA, CC-5079 at 1 mg/kg/d continuous delivered inhibited microvessel formation (P < 0.05). Intraperitoneal CC-5079 was well tolerated and inhibited the growth of subcutaneous MC38 at 100 mg/kg/d (P < 0.01). By qRT-PCR, CC-5079 stimulated MKP1 expression in HUVEC and fibroblast. CONCLUSION: CC-5079 demonstrated stimulation of MKP1, antiangiogenic, and antitumor properties.

A novel technique for quantifying changes in vascular density, endothelial cell proliferation and protein expression in response to modulators of angiogenesis using the chick chorioallantoic membrane (CAM) assay.

Reliable quantitative evaluation of molecular pathways is critical for both drug discovery and treatment monitoring. We have modified the CAM assay to quantitatively measure vascular density, endothelial proliferation, and changes in protein expression in response to anti-angiogenic and pro-angiogenic agents. This improved CAM assay can correlate changes in vascular density with changes seen on a molecular level. We expect that these described modifications will result in a single in vivo assay system, which will improve the ability to investigate molecular mechanisms underlying the angiogenic response.

The effects of gp100 and tyrosinase peptide vaccinations on nevi in melanoma patients.

BACKGROUND: A new approach to prevent disease recurrence in high-risk melanoma patients involves immunization with gp100 and tyrosinase peptides. This is the first study to examine the effects of such treatments on nevi. DESIGN: We studied biopsies of 'clinically atypical' nevi from 10 patients before and after peptide vaccination. All had a cutaneous melanoma measuring at least 1.5 mm in depth, satellite metastases, or at least one positive lymph node. We performed immunohistochemical stains for CD3, CD4, CD8, MHC-I, MHC-II, CD1a, HMB-45, MART-1, tyrosinase, bcl-2, p53, and Ki-67 (mib-1). RESULTS: Immunohistochemistry showed no differences in staining due to vaccination in either the immunologic or melanocytic markers. However, there was a significant increase in both p53 and bcl-2 staining, and a trend toward decreased Ki-67 staining, in the nevi post-treatment. DISCUSSION: The primary goal of peptide vaccinations with gp100 and tyrosinase is to activate melanoma-specific T cells in order to prevent melanoma recurrence. Nevi were studied in order to assess the effects on benign melanocytes. No significant changes in lymphocytes, langerhans cells, expression of MHC antigens, or melanocytic markers were found. The increase in p53 and bcl-2 raises the possibility that vaccination with melanocytic antigens stimulates a response in benign melanocytes.