 | |||||||||
| |||||||||
| Menu | |||||||||
|
 INDUCTION OF CASPASE-MEDIATED APOPTOSIS AND INHIBITION OF PROSTATE TUMOR GROWTH AND METASTASIS BY A PLANT EXTRACT - BIRM®Deven S. Dandekar, Vinata B. Lokeshwar, Edwin Cevallos, and Bal L. Lokeshwar. ddandekar@miami.edu Dept. of Urology and Dept. Sylvester Cancer Center, Univ. of Miami, Miami, Fl. Institute of Tumors, Quito, Ecuador. INTRODUCTION: Most cancer drugs are derived from plants with many more to be discovered (1). An orally active, aqueous plant extract (Dulcamara sp) was tested for its anti-tumor properties on prostate cancer cells in vitro and a metastatic model in vivo. METHODS: Cytotoxicity of BIRM® on three human and one rat-prostate tumor cell lines was evaluated by [3H]-Thymidine incorporation-inhibition and clonogenic survival assays. Apoptotic activity and caspase involvement was assayed by nucleosome release and fluorogenic caspase assays, respectively. Cell cycle-phase fractionation was determined by flow cytometry. Anti-hyaluronidase activity was assayed by an ELISA-like assay. Anti-tumor activity of BIRM® was tested on the Dunning EGFP-MATLyLu rat tumor, a metastatic CaP model. RESULTS: BIRM® inhibited cell proliferation (Fig. 1) and clonogenic growth of CaP cell lines (IC 50 – 0.8% ml/ml). Cells treated with BIRM® showed increased accumulation in GO/Gi phase (33.8%) and decrease 854.6%) in phase 5. Cells incubated with BIRM® underwent apoptosis via activation of caspase-mediated cell death (Fig. 2 & 3). BIRM® inhibited activity of a tumor-derived hyaluronidase (IC50 – 1 ml/ml). Oral administration with BIRM® in MAT LyLu tumor-bearing rats caused a significant decrease in tumor incidence (50%), growth rate (1 cc tumor growth: 18.6 +- 1.3 days in control vs. 25.7 +- 2.6 days (38% growth delay) and a 63% reduction in lung metastasis (Fig. 4 & 5). Fig. 1: DNA synthesis: % of inhibition. Fig. 2: Apoptotic activity. Fig. 3: Relative fluorescence units. Fig. 4: Non-treated tumor volume. Treated with BIRM® – Days post tumor implantation.  CONCLUSION: Our results demonstrate that BIRM® is a potent anti-neoplastic orally active agent, which primarily affects caspase-mediated apoptosis and inhibits metastasis by inhibition of hyaluronidase, an ECM-degrading enzyme implicated in the metastasis. |
||||||||