DESMOLASE ACTIVITY OF NORMAL AND MALIGNANT HUMAN BREAST TISSUE

Abstract

SUMMARY [4-14C]Cholesterol was cleaved to pregnenolone and progesterone by a washed particulate fraction isolated from involved lymph nodes obtained from a radical mastectomy specimen. Difficulties were experienced in isolating subcellular fractions from primary breast tumours and normal breast tissue. However, an acetone powder fraction, obtained from normal tissue derived from a radical mastectomy specimen, yielded pregnenolone from [4-14C]cholesterol. [7α-3H]17α-Hydroxyprogesterone was converted to androstenedione and to 17α,20α-dihydroxypregn-4-en-3-one and its 17α,20β-epimer by homogenates of secondary breast carcinoma tissue and normal breast tissue obtained from radical mastectomy specimens. These results, in conjunction with those obtained previously (Adams & Wong, 1968a), show that human breast carcinoma tissue contains the enzymes necessary to convert cholesterol to androgens and oestrogens.