Methylthioadenosine phosphorylase in human breast cancer.
Methylthioadenosine (MTA) phosphorylase activity was measured in 47 biopsies from primary breast cancers (n = 34) and metastatic tumors (n = 13). Most specimens were also evaluated by DNA flow cytometry and determination of estrogen and progesterone receptor contents. Median MTA phosphorylase activity was 317 pmol/mg protein/min (range 50-1312 pmol/mg protein/min), but great variations were observed. Samples from four individuals had very low MTA phosphorylase activity (less than or equal to 70 pmol/mg protein/min). No correlation with aneuploidy, receptor status, or the presence of metastases in the lymph nodes could be demonstrated. However, MTA phosphorylase activity showed a significant (p = 0.009) negative correlation with the fraction of cells in the S-phase of the cell cycle.
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000201:enzymology* / Q000473:pathology; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007399:Interphase; D008875:Middle Aged; D010430:Pentosyltransferases / Q000032:analysis*; D011683:Purine-Nucleoside Phosphorylase / Q000032:analysis*
D004273:DNA, Neoplasm; D010430:Pentosyltransferases; D011683:Purine-Nucleoside Phosphorylase; C021784:5'-methylthioadenosine phosphorylase