HPMA copolymer-based combination therapy toxic to both prostate cancer stem/progenitor cells and differentiated cells induces durable anti-tumor effects.

Abstract

Current treatments for prostate cancer are still not satisfactory, often resulting in tumor regrowth and metastasis. One of the main reasons for the ineffective anti-prostate cancer treatments is the failure to deplete cancer stem-like cells (CSCs) - a subset of cancer cells with enhanced tumorigenic capacity. Thus, combination of agents against both CSCs and bulk tumor cells may offer better therapeutic benefits. Several molecules with anti-cancer stem/progenitor cell activities have been under preclinical evaluations. However, their low solubility and nonspecific toxicity limit their clinical translation. Herein, we designed a combination macromolecular therapy containing two drug conjugates: HPMA copolymer-cyclopamine conjugate (P-CYP) preferentially toxic to cancer stem/progenitor cells, and HPMA copolymer-docetaxel conjugate (P-DTX) effective in debulking the tumor mass. Both conjugates were synthesized using RAFT (reversible addition-fragmentation chain transfer) polymerization resulting in narrow molecular weight distribution. The killing effects of the two conjugates against bulk tumor cells and CSCs were evaluated in vitro and in vivo. In PC-3 or RC-92a/hTERT prostate cancer cells, P-CYP preferentially kills and impairs the function of CD133+ prostate cancer stem/progenitor cells; P-DTX was able to kill bulk tumor cells instead of CSCs. In a PC-3 xenograft mice model, combination of P-DTX and P-CYP showed the most effective and persistent tumor growth inhibitory effect. In addition, residual tumors contained less CD133+ cancer cells following combination or P-CYP treatments, indicating selective killing of cancer cells with stem/progenitor cell properties.

• Authors: Yan Zhou, Jiyuan Yang, Johng S Rhim, Jindřich Kopeček
• Journal: Journal of controlled release : official journal of the Controlled Release Society (J Control Release) Vol. 172 Issue 3 Pg. 946-53 (Dec 28 2013) ISSN: 1873-4995 [Electronic] Netherlands
• PMID: 24041709 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)
• Copyright: © 2013 Elsevier B.V. All rights reserved.

Chemical References

• Antineoplastic Agents
• Methacrylates
• Taxoids
• Veratrum Alkaloids
• Docetaxel
• hydroxypropyl methacrylate
• cyclopamine

Topics

• Animals
• Antineoplastic Agents (administration & dosage, chemistry, therapeutic use)
• Cell Differentiation (drug effects)
• Cell Line, Tumor
• Docetaxel
• Drug Delivery Systems
• Humans
• Male
• Methacrylates (chemistry)
• Mice
• Mice, Nude
• Neoplastic Stem Cells (drug effects, pathology)
• Prostate (drug effects, pathology)
• Prostatic Neoplasms (drug therapy, pathology)
• Taxoids (administration & dosage, chemistry, therapeutic use)
• Veratrum Alkaloids (administration & dosage, chemistry, therapeutic use)