Most cancers arise in epithelia, the tissue type that lines all body cavities. The organization of epithelia enables them to act as a barrier and perform vectorial transport of molecules between body compartments. Crucial for their organization and function is a highly specialized network of cell adhesion and polarity proteins aligned along the apical-basal axis. Comparing breast and intestinal tissue as examples of common cancer sites, reveals an important contribution of polarity proteins to the initiation and progression of cancer. Defects in polarity are induced directly by mutations in polarity proteins, but also indirectly by changes in the expression of specific microRNAs and altered transcriptional programs that drive cellular differentiation from epithelial to more mesenchymal characteristics. The latter is particularly important in the metastatic process.

中文翻译：

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乳腺癌和结肠癌中细胞和组织组织的变化。

大多数癌症出现在上皮细胞中，这是一种排列在所有体腔内的组织类型。上皮细胞的组织使它们能够充当屏障并在身体隔室之间进行分子的矢量运输。对它们的组织和功能至关重要的是高度专业化的细胞粘附网络和沿顶端-基底轴排列的极性蛋白。将乳房和肠道组织作为常见癌症部位的例子进行比较，揭示了极性蛋白对癌症的发生和进展的重要贡献。极性缺陷直接由极性蛋白的突变引起，但也间接由特定微RNA表达的变化和驱动细胞从上皮细胞分化为更多间充质特征的转录程序改变引起。