Plant-Derived MINA-05 Inhibits Human Prostate Cancer Proliferation In Vitro and Lymph Node Spread In Vivo

Abstract

Few treatment options exist for metastatic prostate cancer (PC) that becomes hormone refractory (HRPC). In vitro, plant-derived MINA-05 caused dose-dependent decreases in cell numbers in HRPC cell lines LNCaPC4-2B and PC-3, and in androgen-sensitive LNCaP-FGC, DuCaP, and LAPC-4, by WST-1 assay. MINA-05 pretreatment significantly decreased clonogenic survival in agar and on plastic at 1 × and 2 × IC50 for PC-3 (P < .05 and P < .001, respectively), and at 1/2 ×, 1 ×, and 2 × IC50 for LNCaP-FGC cells (P < .001). MINA-05 also induced G2M arrest of LNCaP-FGC and PC-3 cells (by flow cytometry) and caused some apoptosis in LNCaPFGC (sub-G1, peak on flow, expression of activated caspase-3) but not in PC-3 cells. Western blotting indicated that these cell cycle changes were associated with decreased levels of regulatory proteins cyclin B1 and cdc25C. MINA-05 given daily by gavage for 39 days did not diminish primary orthotopic PC-3 growth in nude mice, but decreased the extent of lymph node invasion at higher doses. We conclude that MINA-05 induces G2M arrest, inhibits cell growth, reduces PC cell re-growth in vitro, and reduces lymph node invasion after orthotopic PC-3 cell implantation in vivo. It has potential as an adjuvant treatment for patients with PC.

Keywords

• Prostate cancer
• G2M block
• MINA-05 herbal treatment
• lymph node metastases
• clonogenic assays