DEFICIENCY OF QUEUINE, A HIGHLY MODIFIED PURINE BASE, IN TRANSFER-RNAS FROM PRIMARY AND METASTATIC OVARIAN MALIGNANT-TUMORS IN WOMEN

The tRNAs from rapidly growing tissues, particularly from neoplasia, o ften exhibit queuine deficiency. In order to check whether different k inds of ovarian tumors display queuine deficiencies we have analyzed t RNA samples from 16 ovarian malignancies. The tRNAs from histologicall y normal myometrium (4 samples) and myoma (6 samples) were taken as he althy tissue and benign tumor references. Queuine deficiency was deter mined by an exchange assay using [8-H-3]guanine and tRNA:guanine trans glycosylase from Escherichia coli. The mean values of queuine deficien cies in tRNAs were: 10.95 +/- 2.21 (SD) pmol/A(260) in gonadal and ger m cell tumors (5 cases); 23.75 +/- 7.89 pmol/A(260) in primary epithel ial tumors (9 cases); and 34.58 +/- 7.18 pmol/ A(260) in metastatic tu mors (2 cases). These values displayed statistically significant diffe rences (P = 0.0003, Kruskal-Wallis test). The queuine deficiencies in tRNAs significantly increased when moving from well-differentiated thr ough moderately differentiated to poorly differentiated tumors, with t he highest values found in poorly differentiated metastatic tumors (P = 0.0002, Kruskal-Wallis test). Queuine deficiency determination in tR NAs is proposed as a factor for clinical outcome prognosis of ovarian malignancies.