PTGS2 and malignant colon neoplasm: Once we established the experimental parameters of concentrations and periods of treatments of HCT116 cells with DCPIP and DCPIP NPs, we compared the effects of these two agents on the expression of the 44-kDa growth factor, VEGF, and the 72-kDa enzyme, COX-2, which have been associated with angiogenesis, carcinogenesis, and increased incidence of distant metastasis [10], and are robustly expressed in the human colon cancer HCT116 cell line.