SYSTEMIC DELIVERY OF P53 INHIBITS BREAST CANCER

描述：（申请人的摘要）申请人已经报道了一种肿瘤， 与脂质体复合的抑制基因（p53）减弱了 人类乳腺恶性肿瘤 在这些研究中，接种了 乳腺癌细胞，每10-12天注射脂质体：p53 复合体通过尾静脉。 显著减少60%以上， 观察原发肿瘤体积。 此外，还发现， 肿瘤大小不仅受到抑制，而且在大多数情况下都消退了。 p53处理的动物。 还决定， 脂质体：p53复合物降低了这些动物中转移的发生率。 这是第一份针对任何癌症的报告， 系统性提供基因治疗，抑制原发性肿瘤 及其转移。 在本申请中，目标之一是确定 这种疗法的作用机制。 几种假设 将研究野生型p53对肿瘤生长的减少：1） 凋亡途径的激活，2）细胞周期的抑制，和3） 抑制血管生成。 转染的p53是否导致细胞凋亡， 内皮细胞和MDA-MB-435的组织培养实验中的G1阻滞 将检查细胞。 G1期阻滞细胞数的研究 在收获后，还将制备来自原发性肿瘤的细胞。 以来 p53处理的动物中的细胞凋亡增加在第一组中被注意到。 研究，检查肿瘤细胞凋亡的存在和程度将 进行。 然而，代替使用脂质体：p53复合物， 难以检测，脂质体：CAT或脂质体：β-半乳糖苷酶 基因将用于确定分布。 如果 脂质体：CAT/β-半乳糖苷酶标记物不抑制肿瘤细胞 有效地，那么这表明脂质体：p53复合物起作用， 通过旁观者效应。 这种旁观者效应可能是由于抑制 或通过p53诱导IGF-BP 3。 此外，无论 p53和其他基因比单独p53更有效。

DESCRIPTION: (Applicant's Abstract) The applicant has reported that a tumor suppressor gene (p53) complexed to liposomes attenuates the growth of a malignant human breast tumor. In these studies, nude mice, inoculated with breast carcinoma cells, were injected every 10-12 days with a liposome:p53 complex via the tail vein. A marked reduction of greater than 60% in primary tumor volume was observed. Furthermore, it was found that primary tumor size was not only inhibited but regressed in the majority of p53-treated animals. It was also determined that the administration of the liposome:p53 complex reduced the incidence of metastases in these animals. This is the first report for any cancer that demonstrates the effectiveness of gene therapy systemically delivered that has inhibited the primary tumor and its metastases. In this application one of the goals is to determine the mechanism of action of this therapy. Several hypotheses for the reduction of tumor growth by wild-type p53 will be investigated: 1) activation of the apoptotic pathway, 2) inhibition of the cell cycle, and 3) inhibition of angiogenesis. Whether transfected p53 leads to apoptosis or G1 arrest in tissue culture experiments with endothelial and MDA-MB-435 cells will be examined. Investigation of the number of cells in G1 arrest after harvesting the cells from the primary tumor will also be made. Since increased apoptosis in the p53-treated animals were noted in the first study, examination of tumors for the presence and extent of apoptosis will be undertaken. However, instead of using a liposome:p53 complex which is difficult to detect, either a liposome:CAT or liposome:beta-galactosidase gene will be used to determine the distribution. If the liposome:CAT/beta-galactosidase marker does not transfect the tumor cells efficiently, then this suggests that the liposome:p53 complex is acting through a bystander effect. This bystander effect may be due to inhibition of angiogenesis or the induction of IGF-BP3 by p53. In addition, whether p53 and other genes are more effective than p53 alone will be determined.