Using a sequence of @entity172 response elements as a DNA aptamer for XXXX receptors in vitro.

@entity172 @entity1 @entity1238 @entity0 @entity440 @entity55728 @entity5 @entity189 @entity53 @entity1299
@entity172 receptors (ERs) are overexpressed in approximately 70% of @entity0 cases, and they play an important role in tumorigenesis. ERs are strong predictive factors for measuring responses to hormonal therapies. Aptamers are short and single stranded oligonucleotides that are able to recognize target molecules with high affinity. In the present study, we selected and synthesized an oligonucleotide, which has a similar sequence to @entity172 response element in the @entity1238 @entity55728 gene. The synthesized oligonucleotide was evaluated by using immunostaining of paraffin-embedded @entity0 tissues and treating MCF-7 @entity1 mammary @entity189 cell line in vitro. We found that the synthesized oligonucleotide had a high binding affinity to ER similar to @entity53 . Using a specific anti-ER antibody as a standard control, we showed that the synthesized oligonucleotide specifically recognized and immunostained @entity5 cells of @entity0 without cross-reaction with normal tissues. The overall agreement of ER detection between the anti-ER antibody and the ER aptamer was 97.1% (kappa value=0.943; 95% CI=0.879-1.006; p<0.002). Similar to @entity440 or @entity1299 , the oligonucleotide also had an inhibitory effect on cell proliferation of MCF-7 cell line in a dose- and time-dependent fashion but had no cytotoxic effect on @entity1 normal mammary epithelial cells. Therefore, the synthesized oligonucleotide may be used as an aptamer for immunostaining of paraffin-embedded tissue sections for @entity0 diagnosis, as well as a potential ER antagonist in the treatment of @entity0 .
