Adenosine deaminase activity in estrogen receptor positive and negative human breast cancer cell lines

ABSTRACT

The aims of this study were to assay the activity of adenosine deaminase [ADA] in estrogen receptor positive [MCF-7] and negative [MDA-MB468] breast cancer cell lines.MDA-MB468 and MCF-7 breast cancer cell lines were cultured in complete medium, striped serum with and without 0.01micro M diethylstilbestrol [DBS], complete medium in the presence and absence of 1micro M tamoxifen for 20 hr. Adenosine deaminase activity was determined using the colorimetric method described by Guisti and Galanti.It was found that the activity of enzyme in estrogen receptor positive [ER+] cell line [MCF-7] was significantly higher than that of estrogen receptor negative breast cancer cell line [MDA-MB468]. ADA activity in MCF-7 cells cultured in the presence of tamoxifen or charcoal-striped serum was significantly lower than that of control. Furthermore addition of diethylstilbestrol [DBS] to the striped serum increased the value of ADA activity to that of control.Unlike MCF-7 cells, the activity of ADA in MDA-MB468 cells remained unchanged upon treatment with tamoxifen or striped serum.These findings suggest estrogen responsiveness of ADA expression in MCF-7 cells