NATURAL SITE PREFERENCE IN CANCER BIOLOGY

在人类乳房中，一系列微观变化被称为 增殖性乳腺疾病（PBD）。 尽管增生性病变是 在人类乳腺中观察到，它们在疾病进展中的作用不是 明白 PBD的组织病理学特征的进展 与侵袭性疾病发生的风险增加相关 carcinoma. 这些病变最常见的形式是癌症的前兆 或者仅仅是乳房的标记， 肿瘤性病变 PBD的局灶性和显微镜下病变提供了 用于遗传学或其他生物学分析的缺乏组织。 人细胞 来源于乳腺自发永生化的MCF 10A细胞系 从患有纤维囊性疾病的患者获得的上皮细胞。 MCF 10A细胞不能在裸鼠或裸/米色小鼠体内存活。 然而，在这方面， T25 c-Ha-ras癌基因转染的MCF 10 A细胞（MCF 10 AneoT）形成小的 裸鼠/米色小鼠中的结节。 然而，T24 c-Ha-ras癌基因转染 MCF 10A细胞（MCF 10AneoT）在裸/米色小鼠中形成小结节， 持续至少一年，最终进展为非典型 增生，并零星进展为癌。 MCF 10AneoT出现 是能够无限增殖的干细胞， 从正常到非典型的分化范围。 通过重建 组织培养物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，并零星进展为癌。 MCF 10AneoT出现 是能够无限增殖和不同阶段的干细胞 在MCF 10AneoT通过不典型增生向癌进展中， 我们已经能够提供动态过程的静态快照。 这些 当以裸色/米色重新植入体内时，细胞系继续进展 小鼠，但在体外足够稳定以提供必需的工具， 进行基因分析 因此，我们可以中断 通过将细胞置于体外并在体内重新启动进展 在异种移植物中观察到明显的加速进展。 这种独特的模式 具有分析遗传和表观遗传的巨大潜力（即，主机- 介导的）从正常到非典型进展的中心事件 乳腺增生到乳腺癌。 我们的假设是 人类乳腺的连续遗传改变 上皮细胞对正常稳态调节信号的反应。 我们 假设MCF 10AneoT系列进展为恶性 癌伴随着类似于 我们在小鼠中描述的那些，即，致瘤性 MCF 10AneoT的变体将被正常上皮刺激， 基质反应性但不依赖于基质。 虽然Ha-ras不是 在人类乳腺癌中经常发生突变，我们假设， 模型，ras突变模仿其他更常见的遗传效应， 扰动和随后的变化驱动的进展将 在这个人类乳房模型中和在自然疾病中是一样的。 因此，分析遗传变化和稳态反应， 一系列越来越激进的路线将是至关重要的 了解早期乳腺癌的进展。 一个多学科 结合细胞生物学、分子生物学和细胞遗传学的攻击将 被安装来描绘遗传变化和响应于 在每个连续步骤中出现的稳态生长调节因子 进展为非典型增生、原位癌和 MCF 10AenoT.TG异种移植模型中的浸润性癌。

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.