BACKGROUND:?Phospholipid scramblase 1 (PLSCR1) not only participates in the transbilayer movement of phospholipids, but also plays a role in the pathogenesis and progression of cancers. The present study aimed to evaluate the effect of silencing PLSCR1 expression by RNA interference in colorectal cancer (CRC) and metastatic liver cancer. METHODS:?The expression of PLSCR1 in CRC and metastatic liver cancer samples was assessed by immunohistochemistry. The cultured cells with the highest expression were selected for subsequent experiments. We designed three siRNA oligonucleotide segments targeted at PLSCR1. Successful transfection was conifrmed. The biological behavior of the cells in proliferation, adhesion, migration and invasion was determined. RESULTS:?PLSCR1 protein expression increased signiifcantly in the majority of CRC and metastatic liver cancer samples compared with normal samples. Lovo cells had the highest expression of PLSCR1. The siRNA-390 oligonucleotide segment had the best silencing effect. After transfection, Lovo cell proliferation was signiifcantly inhibited compared with the controls in the MTT assay. Laminin and ifbronectin adhesion assays showed Lovo cell adhesion was also signiifcantly inhibited. In the migration assay, the number of migrating cells in the PLSCR1 siRNA-390 group was 50±12, signiifcantly lower than the number in the siRNA-N group (115±28) and in the control group (118±31). In an invasion test, the number of invading cells in the PLSCR1 siRNA-390 group was 60±18,signiifcantly lower than that in the siRNA-N group (97±26) and the control group (103±24). CONCLUSIONS:?PLSCR1 is overexpressed in CRC and metastatic liver cancer. Silencing of PLSCR1 by siRNA inhibits the proliferation, adhesion, migration and invasion of Lovo cells, which suggests that PLSCR1 contributes to the tumorigenesis and tumor progression of CRC. PLSCR1 may be a potential gene therapy target for CRC and associated metastatic liver cancer.