Influence of osteopontin expression on the metastatic growth of CC531 rat colorectal carcinoma cells in rat liver

Development of hepatic metastasis is responsible for most of colorectal cancer-related deaths. Osteopontin (OPN) is a small integrin-binding N-linked glycoprotein, which plays a crucial role in the formation of hepatic metastasis. This study aimed to suppress Opn expression by an antisense-oligonucleotide (ASO Opn ) to decrease liver metastasis in vivo . The effect of ASO Opn was investigated in vitro in CC531 lacZ colorectal cancer cells in comparison to sense (SO) or nonsense (NSO) oligomers, by determining mRNA and protein expression levels, as well as cell survival. For in vivo treatment, CC531 lacZ cells were intraportally inoculated into rats to compare the effects of ASO, SO and NSO oligomers, following prolonged subcutaneous administration by osmotic mini-pumps. The resulting CC531 lacZ tumor cell load in the liver was measured by a β -galactosidase assay. Proliferation of CC531 lacZ cells in vitro was significantly decreased after ASO Opn and SO treatment ( P