Deficiency of Queuine, a Highly Modified Furine Base, in Transfer RNAs from Primary and Metastatic Ovarian Malignant Tumors in Women1

The IUN As from rapidly growing tissues, particularly from neoplasia, often exhibit queuine deficiency. In order to check whether different kinds of ovarian tumors display queuine deficiencies we have analyzed tRNA samples from 16 ovarian malignancies. The tRNAs from histologically normal myometrium (4 samples) and myoma (6 samples) were taken as healthy tissue and benign tumor references. Queuine deficiency was de termined by an exchange assay using (8-'H]guanine and tRNA:guanine transglycosylase from Escherìchiacoli. The mean values of queuine deficiencies in tRNAs were: 10.95 ±2.21 (SD) pmol \ ,,,„ in gonadal and germ cell tumors (5 cases); 23.75 ±7.89 pmol/A260 in primary epithelial tumors (9 cases); and 34.58 ±7.18 pinol A26V in metastatic tumors (2 cases). These values displayed statistically significant differences I/' = 0.0003, Kruskal-Wallis test). The queuine deficiencies in tRNAs significantly increased when moving from welldifferentiated through moderately differentiated to poorly differentiated tumors, with the highest values found in poorly differentiated metastatic tumors i/' = 0.0002, Kruskal-Wallis test). Queuine deficiency determina tion in tRNAs is proposed as a factor for clinical outcome prognosis of ovarian malignancies.