Background: In tumors, monocytes differentiate into tumor-associated macrophages following interaction with cancer cells. We have previously reported that angiogenesis- and chemotaxis-related factors are associated with human monocyte differentiation following interaction with colon cancer cells. However, the exact nature of factors remains unknown. We investigated factors associated with differentiation of human colon cancer cells following interaction with monocytes.
Materials and methods: The human colon cancer cell line DLD-1 was co-cultured with the human monocyte cell line THP-1. mRNA expression was analyzed by quantitative real-time PCR.
Results: Expression of interleukin-1β, matrix metalloproteinase (MMP)-1, MMP-2, and MMP-3 increased in human colon cancer cells after co-culture with monocytes. Conversely, the expression of monocyte chemotactic protein-1, tumor necrosis factor-α, and signal transducer and activator of transcription-3 did not increase.
Conclusion: Differentiation of human colon cancer cells following interaction with monocytes may be associated with angiogenesis and metastasis but not chemotaxis and signaling pathways. Thus, angiogenesis- and metastasis-related factors associated with differentiation of human colon cancer cells may constitute important targets for colon cancer therapy.
Keywords: DLD-1; Monocyte; THP-1 cells; angiogenesis; co-culture; colon cancer cell; metastasis; signaling pathway.