ON THE INCREASE IN SERUM RNASE ACTIVITY IN PATIENTS SUFFERING FROM GYNECOLOGICAL CARCINOMAS

Background: Total RNase activity in human serum is remarkably constant in healthy people but can increase dramatically under pathologic circ umstances, e.g. as concomitant phenomenon of ovarian carcinoma. The ph ysiological duties of the RNases in human serum are not known. Total R Nase activity is used as tumor marker for carcinomas of the female gen itale, preferably ovarian carcinoma. Material and Methods: To investig ate the mechanism of the pathologic increase in RNase activity we deve loped an analytical chromatographic procedure for separation of the se rum RNases. Recovery rates exceeded 90%, which is essential for statem ents of clinical valuer We investigated 65 probands with various benig n and malignant gynecological tumors and 10 healthy women. Results: Ch romatographic separation of the RNases revealed 4 major species (HS-RN ases I-IV), measured toward tRNA as substrate, in all probands. Measur ements toward poly(C) as substrate showed only activity in HS-RNases I I-IV. Activity toward poly(U) was detectable but too low for quantitat ive means. Quantitative differences of the various RNases did occur. W e could not detect significant differences between the nonmalignant pr obands. Differences between patients with ovarian carcinoma and the ot her probands concerning HS-RNase I and II were detectable but not sign ificant. Conclusions: The increase in total serum RNase activity in pa tients with gynecological carcinomas cannot be explained by a signific ant change in the composition. We conclude that the malignant increase in serum RNase activity must be considered as a paraneoplastic effect , possibly with involvement of the liver.