A METASTASIS SUPPRESSOR GENE FOR PROSTATIC CANCER

癌症进展至转移状态 涉及多种细胞和基因变化。利用体细胞 通过杂交，我们证明了转移能力获得 需要转移抑制因子功能的丧失和 致癌基因的激活。我们克隆了一个基因，称为KAI 1， 抑制大鼠前列腺癌细胞系的转移能力。我们 正在研究这种基因影响肿瘤转移的能力， 人前列腺、乳腺、卵巢和结肠细胞系。我们有 发现KAI 1在正常前列腺和乳腺中高度表达 但在癌细胞系中显著降低， 转移性肿瘤我们还发现， 在人膀胱、子宫内膜、肺、结肠 卵巢癌和黑色素瘤细胞系。我们目前正在 开发新的抗体试剂，使KAI 1的研究 在存档的组织切片中表达。我们收集了主要的 以及来自前列腺、结肠、乳腺和 卵巢肿瘤，以研究KAI 1表达是否可以用于 来预测原发性癌症的转移能力。我们也 识别KAI 1结合伴侣，以确定它们如何与KAI 1结合。 可调节KAI 1的功能。我们正在检查已知的候选人 蛋白质，可能与KAI 1在细胞膜上相互作用，但 还试图使用噬菌体展示鉴定新的伴侣， 酵母双杂交筛选。我们已经确定E-钙粘蛋白是 一种与KAI 1复合的蛋白质。我们正在研究 KAI 1在细胞-细胞聚集、粘附和侵袭中的作用， 体外测定。最后，我们正在开发体内转移测定法， 使用各种注射部位来测试KAI 1的能力， 在转移过程的各个阶段抑制多个细胞。 我们比较了KAI 1阳性和 阴性前列腺和卵巢细胞系， 皮下、静脉内和腹膜内部位。我们 打算用这些数据来生成一个模型， 开发KAI 1基因治疗方案。此外，我们在 使用克隆技术的组合来克隆转移灶 染色体8 p上的抑制基因。

Progression of cancer to the metastatic state involves multiple cellular and genetic changes. Using somatic cell hybridization, we demonstrated that acquisition of metastatic ability requires both the loss of metastasis suppressor functions and the activation of oncogenes. We cloned a gene, termed KAI1, that can suppress the metastatic ability of a rat prostatic cancer cell line. We are investigating the ability of this gene to affect the metastasis of human prostate, breast, ovarian, and colon cell lines. We have found that KAI1 is highly expressed in normal prostate and breast epithelial cells but is dramatically lower in cancer cell lines derived from metastatic tumors. We have also found reduced or altered protein expression in human bladder, endometrial, lung, colon, ovarian, and melanoma cancer cell lines. We are currently developing new antibody reagents that will allow study of KAI1 expression in archived tissue sections.We have collected primary and metastatic tumor specimens from prostate, colon, breast, and ovarian tumors to investigate whether KAI1 expression can be used to predict the metastatic ability of primary cancers. We are also identifying KAI1 binding partners in order to determine how they may regulate KAI1 function. We are examining known, candidate proteins, that may interact with KAI1 at the cell membrane, but are also attempting to identify novel partners using phage display and the yeast two-hybrid screen. We have identified that E-cadherin is one protein that complexes with KAI1. We are examining the role of KAI1 in cell-cell aggregation, adhesion, and invasion using in vitro assays. Finally, we are developing in vivo metastasis assays using a variety of injection sites to test the ability of KAI1 to suppress multiple cells at various stages of the metastatic process. We are comparing the induction of metastasis of KAI1 positive and negative prostate and ovarian cell lines following injection at subcutaneous, intravenous and intraperitoneal sites. We are intending to use this data to generate a model that would allow the development of KAI1 gene therapy protocols. In addition, we are using a combination of cloning techniques to clone a metastasis suppressor gene on chromosome 8p.