When exposed to 5-azacytidine, marrow stromal cells from active long-term marrow cultures and cell lines derived from simian virus 40-transformed stromal cells rapidly upregulated c-abl and interleukin-6 transcripts while downregulating the expression of collagen I, a major matrix protein. Similar effects occurred with interleukin-1 alpha and tumor necrosis factor alpha, although the time course was considerably prolonged.
