Abstract 5381: Curcumin induces chemo/radio-sensitization in ovarian cancer cells and curcumin nanoparticles inhibit ovarian cancer cell growth

Abstract Background: Chemo/radio-resistance is a major obstacle in treating advanced ovarian cancer. The efficacy of current treatments may be improved by increasing the sensitivity of cancer cells to chemo/radiation therapies. Curcumin is a naturally occurring compound with anti-cancer activity in multiple cancers; however, its chemo/radio-sensitizing potential is not well studied in ovarian cancer. Herein, we demonstrate the chemo/radio-sensitizing potential of curcumin in a cisplatin resistant ovarian cancer cell line model. Additionally, due to suboptimal pharmacokinetics and low uptake of curcumin in tumors in vivo, we developed a curcumin nanoparticle formulation to improve its therapeutic efficacy. Methods: Cisplatin resistant A2780CP ovarian cancer cells were pre-treated with curcumin followed by exposure to cisplatin or radiation and the effect on cell growth was determined by MTS and colony formation assays. The effect of curcumin pre-treatment on the expression of apoptosis related proteins and β-catenin was determined by Western blotting or Flow Cytometry. A luciferase reporter assay was used to determine the effect of curcumin on β-catenin transcription activity. The poly(lactic acid-co-glycolic acid) (PLGA) nanoparticle formulation of curcumin (Nano-CUR) was developed by a modified nano-precipitation method and physico-chemical characterization was performed by transmission electron microscopy and dynamic light scattering methods. Results: Curcumin pre-treatment considerably reduced the dose of cisplatin and radiation required to inhibit the growth of cisplatin resistant ovarian cancer cells. During the 6 hrs pre-treatment, curcumin down regulated the expression of Bcl-XL and Mcl-1 pro-survival proteins. Curcumin pre-treatment followed by exposure to low doses of cisplatin increased apoptosis as indicated by annexin V staining and cleavage of caspase 9 and Poly (ADP-ribose) polymerase (PARP). Additionally, curcumin pre-treatment lowered β-catenin expression and transcriptional activity. Physico-chemical characterization of Nano-CUR indicated an average particle size of ∼70 nm, steady release of curcumin over a period of 18 days and antibody conjugation characteristics. The Nano-CUR formulation also effectively inhibited the growth of ovarian cancer cells. Conclusion: Curcumin pre-treatment enhances chemo/radio-sensitization in A2780CP ovarian cancer cells through multiple molecular mechanisms. Therefore, curcumin pre-treatment may effectively improve ovarian cancer therapeutics. A targeted PLGA nanoparticle formulation of curcumin is feasible and may improve the in vivo therapeutic efficacy of curcumin. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5381.