I am studying a medicl paper. I don't know the meaning of this words. for example in the following sentence:
We demonstrated that these bioconjugates can efficiently target and get taken up by the prostate epithelial cells, which express the prostate-specific membrane antigen protein In contrast to cells, the uptake of these particles is not enhanced in cells that do not express the prostate-specific membrane antigen protein.
ما نشان دادیم که این بایوترکیب ها می توانند به طور موثری هدف دهی شوند و به وسیله سلول های اپیتلیال پروستات جذب شوند که ؟؟؟ از اینجاشو بلد نیستم
or in the following sentence:
we generated nanoparticle-aptamer bioconjugates with RNA aptamers that bind to the prostate-specific membrane antigen, a well-known prostate cancer tumor marker that is overexpressed on prostate acinar epithelial cells.
thanks a lot for ur help

thanks a lot but I think express doesn't mean represent or explain here...

overexpress = بیش از اندازه اثر خود را نشان دادن