NATURAL SITE PREFERENCE IN CANCER BIOLOGY

在人类乳房中，一系列微观变化被称为 增生性乳腺疾病(PBD)。尽管增生性病变 在人类乳房观察到，它们在疾病进展中的作用不是 明白了。多发性骨髓瘤的组织病理学特征进展 与侵袭性疾病发展的风险增加相关 癌症。这些病变最严重的形式是癌症的前兆。 或者仅仅是乳房的标记，很可能导致独立 肿瘤损伤。PBD的局灶性和显微镜病变提供了 缺乏用于遗传或其他生物分析的组织。一种人类细胞 品系(MCF10A)起源于乳腺的自发永生化 取自一位纤维囊性疾病患者的上皮细胞。 MCF10A细胞不能在裸鼠或裸鼠体内存活。然而， 转导c-Ha-ras癌基因的MCF10A细胞(MCF10AneT) 裸鼠/褐鼠的结节。而T24 c-Ha-ras癌基因转染组 MCF10A细胞(MCF10AneT)在裸鼠体内形成小结节 持续至少一年，最终进展为非典型 增生，零星地进展为癌症。MCF10AneT出现 是一种能够无限增殖的干细胞，具有广泛的 分化范围从正常到不典型。通过重建 组织培养中的细胞来自代表不同阶段的病变 其中持续至少一年，最终进展为非典型 增生，零星地进展为癌症。MCF10AneT出现 成为能够无限增殖和不同阶段的干细胞 在MCF10AneT通过不典型增生进展为癌的过程中， 我们已经能够提供动态过程的静态快照。这些 裸鼠体内移植后细胞株继续进展 小鼠，但在体外足够稳定，足以提供必要的工具 进行进化的基因分析。因此，我们能够中断 体外放置细胞进展和体内重新启动的进展 在异种移植物中观察到明显的沉淀进展。这种独特的模式 在分析遗传和表观遗传学方面具有巨大的潜力(例如，宿主- 中介的)事件是从正常到非典型进展的核心 人类乳房的增生性转化为癌。我们的假设是 顺序的基因改变加速了人类乳房的变化 上皮细胞对正常内环境平衡调节信号的反应。我们 假设MCF10AneT系列细胞向恶性进展 癌症伴随着动态平衡反应的变化 我们在小鼠身上描述的那些，也就是致癌 MCF10AneT的变异体将被正常的上皮和BE刺激 基质反应，但不依赖基质。尽管哈拉斯不是 在人类乳腺癌中频繁突变，我们假设，在这个 模型中，ras突变模仿了其他更常见的基因的影响。 扰动和随后的改变将推动进步 在这个人类乳房模型中与在自然疾病中是相同的。 因此，对遗传变化和寄居反应的分析 一系列日益咄咄逼人的路线将与 了解早期乳腺癌的进展情况。一个多学科的 结合细胞生物学、分子生物学和细胞遗传学的攻击将 被装载以描述基因变化和响应 在每一连续步骤中出现的动态平衡生长调节因子 进展为不典型增生、原位癌和 MCF10AenoT.TG异种移植瘤模型中的浸润性癌

In the human breast, a spectrum of microscopic changes has been termed proliferative breast disease (PBD). Although hyperplastic lesions are observed in human breast, their role in disease progression is not understood. The progression of histopathological features of PBD has been correlated with increased risk for the development of invasive carcinoma. The most serve form of these lesions are precursors of cancer or simply markers of breasts likely to give rise to independent neoplastic lesions. The focal and microscopic lesions of PBD provide scant tissues for genetic or other biological analyses. A human cell line (MCF10A) originated from spontaneous immortalization of breast epithelial cells obtained from a patient with fibrocystic disease. MCF10A cells do not survive in vivo in Nude or Nude/Beige mice. However, T25 c-Ha-ras oncogene-transfected MCF10A cells (MCF10AneoT) form small nodules in Nude/Beige mice. However, T24 c-Ha-ras oncogene-transfected MCF10A cells (MCF10AneoT) form small nodules in Nude/Beige mice which persist for at least one year, eventually progress to atypical hyperplasia, and sporadically progress to carcinomas. MCF10AneoT appear to be stem cells capable of indefinite proliferation and with a wide range of differentiation from normal to atypical. By reestablishing cells in tissue culture from lesions representing different stages in in which persist for at least one year, eventually progress to atypical hyperplasia, and sporadically progress to carcinomas. MCF10AneoT appear to be stem cells capable of indefinite proliferation and different stages in progression of MCF10AneoT through atypical hyperplasia to carcinomas, we have been able to provide still snapshots of a dynamic process. These cell lines continue to progress when reimplanted in vivo in Nude/Beige mice but are sufficiently stable in vitro to provide the tools essential for he genetic analysis of progression. Thus, we are able to interrupt progression by placing cells in vitro and reinitiated progresses in vivo precipitate overt progression observed in xenografts. This unique model has great potential for analyzing genetic and epigenetic (i.eg., host- mediated) events central to progression from normal to atypical hyperplasia to carcinoma in the human breast. Our hypothesis is that sequential genetic alterations precipitate changes in human breast epithelial responses to normal homeostatic regulatory signals. We hypothesize that the progression of the MCF10AneoT series to malignant carcinomas is accompanied by changes in homeostatic responses similar to those which we have described in the mouse, i.e., that tumorigenic variants of MCF10AneoT will be stimulated by normal epithelium and be stromal-responsive but not stromal-dependent. Although Ha-ras is not frequently mutated in human breast cancer, we hypothesize that, in this model, the ras mutation mimics the effect of other, more common genetic perturbations and that subsequent alterations driving progression will be the same in this human breast model as in the natural disease. Therefore, analysis of genetic changes and homestatic responses with a series of increasingly aggressive lines will be vitally relevant for the understanding of early breast cancer progression. A multidisciplinary attack combining cell biology, molecular biology, and cytogenetics will be mounted to delineate genetic changes and changes in response to homeostatic growth regulatory factors which occur at each sequential step of progression to atypical hyperplasia, to carcinoma in situ, and to invasive carcinoma in the MCF10AenoT.TG xenograft model.