Description
The gain of Protocadherin LKC (PCDH24) expression in colon carcinoma cell line HCT116 has been shown to induce contact inhibition, thereby completely abolishing tumor formation in vivo. To clarify the molecular mechanism, we performed DNA microarray analysis and compared gene-expression pattern between control and PCDH24-expressing HCT116 cells. Approximately 2000 genes were apparently changed their expression. Further proteomics analysis using 2-DE/MS confirmed the dramatic changes and provided additional information. We were aware that these changes are quite similar to the changes observed in epithelial-mesenchymal transition (EMT), most drastic changes in development and cancer metastasis. We thus further analyzed these changes using specific antibodies, and found distinct difference between these two phenomena. Among the differences, nuclear translocation of catenin beta 1 (CTNNB1) was inhibited by PCDH24-expression, subsequently some of the downstream nodes were suppressed. Although contact inhibition and cancer metastasis are completely opposite aspect of the cells, we expect that the identified differences will be key nodes to understand the relationship. We also expect that the nodes will be a target to modulate tumors arising stem cell transplantation (SCT), as well as a therapeutic target for cancer metastasis.