Abstract 4591: Comparison of the inhibitory effects of unmodified and modified combinations of chemopreventive agents on MIA PaCa-2 and Panc-1 human pancreatic cancer cell lines

Abstract

Abstract Pancreatic cancer is the fourth leading cause of death in the United States with approximately 40,000 estimated deaths in 2010. The objective of our study was to compare the effectiveness of chemopreventive combination regimens of aspirin, curcumin and sulforaphane (ACS) administered in unmodified (free drug) and in modified forms, encapsulated within solid lipid nanoparticles (SLNs), on the MIA PaCa-2 and Panc-1 human pancreatic cancer cell lines. MTS cell proliferation and apoptosis assay studies were conducted on cultured cells. For the MTS assay, upon 75 % confluence, 2.5 × 103 cells for MIA PaCa-2 and 4 × 103 cells for Panc-1 were transferred into each well of 96-well plates. The ACS chemopreventive agents alone or in combination were added to the cells and incubated for 72 h. Absorbance was recorded at 490 nm using an ELISA plate reader. For the apoptosis assay, 3 × 105 cells were cultured in 6-well plates for both Panc-1 and MIA PaCa-2 cell-lines. ACS, individual or combinations, were added and the plates were incubated for 72 h. Cells were analyzed using flow cytometry, measuring the fluorescence emission at 530 nm (FL1) and >575 nm (FL3). IC50 values obtained for the respective unmodified and modified forms of aspirin were (2.05mM/L; 66.08µM/L), curcumin (16.05µM/L; 4.93µM/L) and free sulforaphane at 11.82 µM/L for MIA PaCa-2 cells. Similarly, for Panc-1 cells, the IC50 values for unmodified and modified aspirin were (2.42mM/L; 90.23µM/L), curcumin (24.01 µM/L; 7.5µM/L) respectively and free sulforaphane at 17.81µM/L. For MIA PaCa-2 cell line, unmodified combinations of aspirin (1mM/L) with curcumin (10µM/L) and sulforaphane (5µM/L) showed significant reduction in cell viability of >60% using MTS assay. In comparison, aspirin SLN (25µM/L), curcumin SLN (2.5µM/L) and free sulforaphane (5µM/L) mixtures showed cell viability of >55%. Flow cytometry analysis demonstrated apoptosis of 63% (unmodified) and 50% (modified) for the combinations, at the same concentration ranges as above. For the Panc-1 cell line, treatment with similar concentrations of unmodified and modified SLN combinations showed a >75% and >60% decrease in cell viability (MTS assay) and 63% and 54% induction of apoptosis cells, respectively. Our results demonstrated that the drugs when encapsulated in SLNs at lower concentrations exhibited decreasing cell proliferation and increased induction of apoptosis within the pancreatic cancer cell lines. This data provides compelling evidence of the potential of the SLN carrier system in designing in-vivo studies for the pancreatic cancer chemoprevention. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4591. doi:10.1158/1538-7445.AM2011-4591