Targeting gene therapy for prostate cancer using prostate specific antigen (PSA)

作为一种新的前列腺癌治疗方法，我们正在LNCaP人类前列腺癌模型中研究一种利用自杀基因胞嘧啶脱氨酶（CD）将无毒的5-氟胞嘧啶（5-FC）代谢为有毒的5-氟尿嘧啶（5-FU）的基因治疗模型。采用pC/CD载体转染LNCaP细胞。5 -FC对克隆LN/CD的ID50值明显低于转染空载体的对照细胞，对5- fu敏感。用LN/CD接种裸鼠后，注射5-FC后肿瘤消退。CD基因的表达对LNCaP前列腺癌模型在体内和体外均有治疗作用。我们使用来自PSMA基因的调控元件来开发一种结构，该结构可用于在针对该疾病的基因治疗方法中控制CD基因的表达。我们最近克隆了PSMA基因的启动子，该基因可以驱动前列腺特异性表达荧光素酶报告基因。NF κ B抑制剂吡咯烷二硫代氨基甲酸酯（PDTC）和NF κ B诱饵持续抑制TNF-α-诱导的NF κ B活化。TNF-α (20 ng/ml)联合NF κ B抑制剂对前列腺癌细胞有明显的生长抑制作用。TNF-α和NF κ B抑制剂联合治疗前列腺癌是一种有效的治疗方法。我们评估了条件复制单纯疱疹病毒1 （HSV-1）载体G207在体外和体内对前列腺癌的抗肿瘤作用。DU145和PC3在7天内被G207有效破坏。G207的病毒产量随时间的增加而增加。在体内，瘤内接种G207诱导了肿瘤生长的显著抑制。病理研究发现，在g207治疗的肿瘤中，大量lacZ阳性细胞弥漫性存在。因此，G207可被认为是治疗前列腺癌的有用药物。

As a new treatment of prostate cancer, we are investigating a gene therapy model that utilizes a suicide gene cytosine deaminase (CD) that metabolizes non-toxic 5-fluorocytosine (5-FC) into toxic 5-fluorouracil (5-FU) in a LNCaP human prostate cancer model. The vector pC/CD was used to transfect LNCaP cells. 5 -FC showed a significantly lower ID50 value against the clones LN/CD than the control cells transfected with an empty vector, which was sensitive to 5-FU.Tumors made with LN/CD inoculation in nude mice were shown to regress after i.p.administration of 5-FC.The expression of the CD gene was effective in therapy of the LNCaP prostate cancer model both in vitro and in vivo. We used regulatory elements from the PSMA gene to develop a construct that could be used to control expression of a CD gene in a gene therapy approach against this disease. We recently cloned the promoter of the PSMA gene, which can drive prostate-specific expression of a luciferase reporter gene.NF κ B inhibitors, pyrrolidine dithiocarbamate (PDTC) and NF κ B decoy, continuously inhibited TNF-α-induced NF κ B activation. Prostate cancer cells treated with TNF-α (20 ng/ml) plus NF κ B inhibitors showed significant growth inhibition. The combination of TNF-α and NF κ B inhibitors was suggested to be an effective therapy for prostate cancer.We evaluate the antitumoral effect of a conditionally-replicating herpes simplex virus 1 (HSV-1) vector, G207, against prostate cancer in vitro and in vivo. DU145 and PC3 were efficiently destroyed by G207 within 7 days. The viral yields of G207 increased time-dependently. In vivo, the intraneoplastic inoculation of G207 induced a significant inhibition of the tumor growth. In a pathological study, a large number of lacZ positive cells were diffusely present in the G207-treated tumors. G207 thus may be considered a useful agent for the treatment of prostate cancer.