Metabolism of pregnenolone by human breast cancer. Evidence for 17α-hydroxylase and 17,20-lyase

Y. J. Abul-Hajj, R. Iverson, D. T. Kiang

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


The metabolism of 7- 3H-pregnenolone was studied in vitro using 16 human breast carcinomas. All mammary tumors transformed pregnenolone to progesterone. All estrogen receptor poor tumors and 4 out of 8 estrogen receptor rich tumors converted pregnenolone to 17-hydroxypregnenolone. Five estrogen receptor poor tumors showed the presence of 17,20-lyase as evidenced by formation of dehydroepiandro-sterone and androstenedione. In two estrogen receptor poor tumors, conversions of pregnenolone to progesterone, 17-hydroxy pregnenolone, dehydroepiandrosterone androstenedione and finally to estradiol was documented, providing a hypothetical pathway for steroid metabolism in human breast cancer. The conversion of pregnenolone to 17-hydroxy-pregnenolone was significantly less in receptor rich tumors and was totally absent in 4 receptor rich tumors with estrogen receptors of over 45 fmol/mg protein.

Original languageEnglish (US)
Pages (from-to)817-827
Number of pages11
Issue number7
StatePublished - Dec 1979

Bibliographical note

Funding Information:
This investigation was supported in part Grants CA 20530 and CA22467 from the National the Graduate School, University of Minnesota

Copyright 2014 Elsevier B.V., All rights reserved.


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