Metabolism of the isoflavones genistein and biochanin A in human breast cancer cell lines.

There is substantial variation in the growth inhibition of different human breast cancer cell lines by the isoflavones genistein and biochanin A. ZR-75-1 and BT-20 cells are > or = 2- to 4-fold less sensitive to these isoflavones than are MCF-7 cells, whereas T47D cells have a sensitivity similar to that of MCF-7 cells. To determine whether these differences are related to isoflavone metabolism by these cancer cells, each of the cell lines was incubated with [4-(14)C]genistein and [4-(14)C]biochanin A. Metabolites in the cell culture media were identified by radio-HPLC electrospray ionization mass spectrometry. One metabolite of genistein (genistein 7-sulfate) and 2 metabolites of biochanin A (genistein and genistein 7-sulfate) were detected by radio-HPLC. Further analysis by mass spectrometry identified 3 other metabolites, a hydroxylated methylated form of each isoflavone and a biochanin A sulfate. IC50 (the concentration at which the growth rate was halved) values of the breast cancer cell lines did not correlate well with production of genistein 7-sulfate from genistein or with biochanin A sulfate, genistein 7-sulfate, or genistein from biochanin A. However, IC50 values correlated with the production of the hydroxylated and methylated forms of the isoflavones. Only T47D cells produced these metabolites in this study, and only T47D cells had IC50 values similar to those of MCF-7 cells, which also produced the hydroxylated and methylated metabolites. These data suggest that the hydroxylated and methylated metabolites may be the active forms of genistein in human breast cancer cells and emphasize the importance of isoflavone metabolism in the mechanism of action of isoflavones.

[Congenital absence of upper anterior teeth a dentofacial morphologic analysis].

OBJECTIVE: This study was designed to examine the dentofacial morphology of the children in Shanghai with congenital absence of upper anterior teeth. METHODS: Cephalometric analysis for 37 children with congenital absence of upper anterior teeth was conducted and was compared with that of the normal ones. RESULTS: (1) There was no significant difference in all measurements between gender. (2) Craniofacial defection included a small SNA a small ANB a small AoBo a small angle of convexity,and a large AB plane angle. Vertical facial dimensions which was shown by Y axis and mandibular plane angle significantly decreased. Examination for soft tissue also revealed a small convexity of soft tissue and a large CmSnUL. (3) A compensative proclination of the upper central incisors as well as the upper lip was also found. CONCLUSION: Patients with congenital absence of upper anterior teeth might have a small maxilla a relatively normal mandibular dimension an anticlock rotation of the mandible plane, and a compensative proclination of the upper central incisors and the upper lip.