Differential expression of autocrine motility factor receptor (AMFR) mRNA in normal and cancer cells detected by in situ hybridization

Abstract

The receptor for autocrine motility factor (AMFR) is known to be involved in the process of AMF-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 or 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 FHs738BL human 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 downregulation 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 regulated and controlled at the transcriptional level. 222In situ hybridization detection of AMFR mRNA