Autotaxin expression in non-small-cell lung cancer

Autotaxin (ATX) is one of the newly discovered autocrine motility-stimulati ng: factors with peptide sequences identical to those of the brain-type pho sphodiesterase I (PD-Ic(). Although ATX/PD-I alpha is believed to play a ro le in tumor progression, its expression in various human cancers has not be en extensively studied. We have studied the expression of ATX messenger RNA (mRNA) in normal human bronchial epithelial cell (HBEC) and non-small-cell lung cancer (NSCLC) cell lines, and in primary NSCLC with their correspond ing normal lung tissues, using reverse transcription-polymerase chain react ion, Northern blot analysis, and in situ hybridization. ATX mRNA was common ly expressed in these cell lines and tissues. The predominantly expressed m RNA species corresponded to the ATX complementary DNA isolated from a human teratocarcinoma cell line. Overexpression of ATX mRNA was detected in seve n of 12 (58%) tumor cell lines, however, there was no correlation between t he levels of expression of ATX mRNA and the spontaneous motility of these c ells, in situ hybridization localized ATX mRNA expression to the basal cell s of normal bronchial epithelium, stromal B lymphocytes, and tumor cells. A n overexpression of ATX mRNA as compared with its expression in normal bron chial epithelium was mainly found in poorly differentiated carcinomas. Our findings suggest that ATX may have roles additional to its motility-stimula ting function in undifferentiated NSCLC.