Study On The Mechanism Of Aptamer-binding Targets Of Prostatic Carcinoma Cells

Prostate cancer is one of the most common malignancies of the male urinary system.With the rapid increase of aging in China,the incidence of prostate cancer has increased significantly in recent years.Early diagnosis of prostate cancer mainly depend on the change of prostate specific antigen(prostate-specific antigen,PSA)levels,while this method is low specificity due to the change of the patient's body PSA levels that is affected by many factors.There are many excessive treatment situation in the process of diagnosis which lead to unnecessary biopsies and great pain to the patient.Therefore,finding effective tumor markers is the key to the diagnosis of prostate cancer.Nucleic acid aptamers have the characteristics of strong specificity,wide recognition range and low immunogenicity,providing a new way for the search of potential tumor markers.In our previous study,human prostatic carcinoma cell line DU145 was used as the positive selection cells line,and human prostatic stromal myofibroblast cell line WPMY-1 was used as the negative selection cell line to obtain a nucleic acid aptamer DML-7 during the cell-selex technology.DML-7 can combine prostate cancer cells and tissues.It has a high affinity to DU145 cells and can be internalized into cells.DML-7 has a great potential in the diagnosis and treatment of tumor,but its binding target is not clear.The main research contents of this paper include:(1)To investigate the ability of nucleic acid aptamer DML-7 in combination with prostatic carcinoma cells and the biological function activity in physiological temperature conditions,we found that the DML-7 can bound androgen independent human prostatic carcinoma cell lines DU145 and PC-3,but not the androgen dependent human prostate cancer cell line 22Rv1 and the human prostatic stromal myofibroblast cell line WPMY-1.In order to clear the biological activity of DML-7 on prostate cancer cell DU145,DML-7 incubated with prostate cancer cell DU145 for 72 h.we found that the DML-7 had no effect on DU145 cells survival.(2)Discovery and identification of the target of nucleic acid aptamer DML-7 binding to DU145 cells.Through biomass spectrometry,we found that the protein binding to DML-7 might be integrin alpha3beta1,which was further proved to be the target molecule of DML-7 by aptamer-pull down,RNA interference and co-localization experiments.In this paper,integrin alpha3beta1 was identified as the target molecule for the binding of nucleic acid aptamer DML-7 to prostate cancer cells,providing a new potential biomarker for the diagnosis of prostate cancer and a new way for the treatment of prostate cancer.