CALMODULIN-LIKE EFFECT OF ONCOMODULIN ON CELL-PROLIFERATION

Oncomodulin (OM) is a Ca2+ binding protein (CABP) structurally closely related to parvalbumin. Expression of OM is restricted to early embry onic stages, the placental cytotrophoblasts, and neoplastic tissues. T he function of OM as a calmodu lin (CaM)-like enzyme modulator is cont roversial. Two types of experiments demonstrate that OM may act in an analogous fashion to CaM in T14 and T10 cancerous cell lines, which bo th express OM. First, both OM transcript and protein levels increased at the G1/S boundary in a similar manner to CaM, though not to the sam e extent, in the chemically transformed rat fibroblast cell line T14 s ynchronized at mitosis by nocodazole. Second, antisense oligonucleotid es specific to the OM ATG region inhibited growth of T14 in a similar dose-dependent manner as observed with CaM-specific antisense probes. (C) 1994 Wiley-Liss, Inc.