Objective    To explore whether bone morphogenic protein-7 can induce mesenchymal to epithelial transition in adult renal fibroblasts.     Methods    Human renal fibroblasts isolated from the resected kidney tissues owing to renal tumors were primarily cultured. The passage 3 renal fibroblasts were used in this experiment. The morphologic changes of the renal fibroblasts were observed by phase contrast microscopy after being subjected to DMEM-F12 control medium or medium containing 1 000 ng/ml rhBMP-7 for 72 h. The cell proliferation was measured by MTT. The levels of type I collagen secretion in supernatant was determined by ELISA. E-cadherin and Pax2 protein expressions were detected by Western blot.     Results    Incubation of adult renal fibroblasts with 1 000 ng/ml rhBMP-7 induced the formation of epithelial cell aggregates within the confluent cell monolayer. The proliferation of the renal fibroblasts and the type I collagen expressions were decreased while E-cadherin and Pax2 expressions were increased

as compared with the untreated fibroblasts.     Conclusion    Adult renal fibroblasts have retained at least part of their embryonic epithelial imprint and plasticity. BMP-7 can induce renal fibroblast to epithelial cell.