gms | German Medical Science

Introduction: Since the detection of the new miRNA induced truncation mechanism which results in the C-terminal truncation of proteins with the elongation of unique amino acids, more and more protein could be analyzed. Recently a specific androgen receptor miRNA binding site was analyzed after the exon 6 in the region of the intron 7. This interaction results in the truncation of the androgen receptor with a unique C-terminal ending.

Materials and Methods: For the detection of this unique variant, special primers against the c-terminal ending were designed and PCR was performed. The new antibody was also designed against the unique C-terminal ending and Western Blot as well as immunofluorescence was established on BPH, LNCap, PC3 and DU145 cells.

Results: It was possible to show on mRNA level with special designed primers that LNCap cells express less amount of the novel AR mRNA than PC3 and DU145 cells. The antibody, designed against the unique C-terminal ending (KoeHei 125) and the performed Western Blot from BPH, LNCap, PC3 and DU145 cells also show the same results. In the cell lines PC3 and DU145, high levels of the KoeHei125 were detectable. Nevertheless, this cell lines are usually AR negative. In the LNCap and BPH cell lines the KoeHei125 levels were lower. In immunofluorescence of all used cell lines, signals could be detected. The localization of the signals differs, in DU145 and PC3 the signal was predominantly located in the nucleus and the nuclear membrane, whereas it was cytoplasmic in BPH and LNCap cells. The exact biological role of this novel receptor needs to be analyzed in the future.