ABSTRACT
Objective:Apt-A10-3.2 (aptamer of prostate specific membrane antigen (PSMA)) can be used as a specific ligand for early diagnosis and targeted treatment of prostate cancer. Mouse double minute 2 homolog (MDM2) is closely related to the malignancy of prostate cancer, and MDM2 small interfering RNA (siRNA) can silence MDM2 gene through RNA interference. To design a novel chimera of PSMA Apt-MDM2 siRNA and combine it with docetaxel (DTX) to explore a new diagnosis and treatment model combining targeted therapy of PSMA-positive prostate cancer with 99Tc m-chimera imaging monitoring. Methods:Apt-siRNA were obtained by covalent connection of PSMA Apt-A10-3.2 and MDM2 siRNA, which was combined with DTX to treat PSMA-positive prostate cancer cell lines (22RV1 and LNCaP). Cell lines were treated with Apt-siRNA alone or in combination with DTX. The levels of MDM2 and apoptosis-related proteins (B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X (Bax), poly ADP-ribose polymerase (PARP), caspase-3) were detected by Western blot, which were used to evaluate the therapeutic effect. Fifteen BALB/c mice bearing 22RV1 xenografts were treated with PBS, DTX+ Apt-siRNA (200 pmol) and DTX+ Apt-siRNA (400 pmol), respectively. Tumor volume and MDM2 level were observed, and 99Tc m-Apt-siRNA SPECT imaging was performed to obtain the tumor/muscle (T/M) ratio. One-way analysis of variance, Tukey′s test and linear regression analysis were used for data analysis. Results:The levels of MDM2 protein were significantly decreased by Apt-siRNA (0.25±0.02, F=183.40, P<0.001; 0.56±0.03, F=37.15, P<0.001) in 22RV1 and LNCaP cells. After the treatment of Apt-siRNA+ DTX, the levels of Bcl-2 were significantly decreased, and the levels of Bax, PARP and caspase-3 were significantly increased. MDM2 protein level (400 pmol: 0.59±0.12; F=49.99, P=0.023) and tumor volume (400 pmol: (0.22±0.07) cm 3;F=71.30, P=0.039) were significantly inhibited by Apt-siRNA+ DTX in mice bearing 22RV1 xenografts. As for 99Tc m-Apt-siRNA SPECT imaging in vivo, T/M ratio of treatment group was significantly decreased (400 pmol: 2.07±0.22; F=34.99, P=0.022), and there was a linear regression relationship between T/M ratio and the expression level of MDM2 ( R2=0.875, P<0.001). Conclusion:Apt-siRNA combined with DTX can effectively inhibit the progression of prostate cancer, and realize visual targeted diagnosis and treatment of PSMA-positive prostate cancer by coupling radionuclide technetium.
ABSTRACT
Thyroid cancer is the most common malignancy in the endocrine system .In recent years ,the incidence of thyroid cancer has increased year by year ,which sparked people′s attention.With the development of thyroid cancer research ,it is found that cytokines play a key role in the occurrence and development of tumor .At present ,the cause of thyroid carcinoma and mechanism is not yet entirely clear ,however ,the occurrence of thyroid cancer is possiblely associated with the body regulating cellular immune dysfunction .Cytokines play an important role in the whole process ,in which the relationship between cytokines IFN -γ,IL-6 and thyroid carcinoma is closely related .