The receptor for autocrine motility factor(AMFR) is known to be involved in the process of MF-mediated cell migration and metastasis.This paper describes the procedures of non-radioactive in situ hybridization(ISH) detection of AMFR mRNA in both paraffin-embedded surgical sections and cultured cells using either biotinylated oligonucleotide probes of digoxigenin-labeled RNA probes.The results showed that the AMFR mRNA was expressed at an enhanced level in hyperplastic and malignant tissues of breast and prostate cancer patient surgical specimens,indicating that the elevated AMFR expression was associated with the tissue malignancy.Moreover,AMFR mRNA was detected in both normal and carcinoma cells when cultured at a subconfluent density.However,AMFR expression was inhibited in confluent normal(3T3-A31 murine fibroblast and FHs 738 BL huamn bladder)cells while it continued to express in carcinoma(J82 human bladder) and metastatic(3T3-M murine fibroblast) cells irrespective of cell density.This suggested a cell-cell contact down-regulation of AMFR mRNA expression in normal but not in cancer cells.The ISH data obtained in this study are closely consistent with the AMFR protein expression pattern previously reported,implying that the differential expression of AMFR gene may be rgeualted and controlled at the transcriptional level.