Cancers originally develop from normal cells that gain the ability to proliferate aberrantly and eventually turn malignant. These cancerous cells then grow clonally into tumors and eventually have the potential to metastasize. A central question in cancer biology is, which cells can be transformed to form tumors? Recent studies elucidated the presence of cancer stem cells that have the exclusive ability to regenerate tumors. These cancer stem cells share many characteristics with normal stem cells, including self-renewal and differentiation. With the growing evidence that cancer stem cells exist in a wide array of tumors, it is becoming increasingly important to understand the molecular mechanisms that regulate self-renewal and differentiation because corruption of genes involved in these pathways likely participates in tumor growth. This new paradigm of oncogenesis has been validated in a growing list of tumors. Studies of normal and cancer stem cells from the same tissue have shed light on the ontogeny of tumors. That signaling pathways such as Bmi1 and Wnt have similar effects in normal and cancer stem cell self-renewal suggests that common molecular pathways regulate both populations. Understanding the biology of cancer stem cells will contribute to the identification of molecular targets important for future therapies.

中文翻译：

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癌症干细胞的生物学。

癌症最初从正常细胞发展而来，该细胞具有异常增殖并最终变成恶性的能力。这些癌细胞然后克隆生长成肿瘤，最终具有转移的潜力。癌症生物学中的一个核心问题是，哪些细胞可以转化为肿瘤？最近的研究阐明了癌症干细胞的存在，它们具有再生肿瘤的独特能力。这些癌症干细胞与正常干细胞具有许多特征，包括自我更新和分化。随着越来越多的证据表明癌症干细胞存在于多种肿瘤中，了解调节自我更新和分化的分子机制变得越来越重要，因为参与这些途径的基因的破坏很可能参与了肿瘤的生长。这种新的肿瘤发生范例已在越来越多的肿瘤中得到验证。来自同一组织的正常和癌细胞干细胞的研究为肿瘤的发生提供了线索。诸如Bmi1和Wnt的信号通路在正常和癌症干细胞自我更新中具有相似的作用，表明共同的分子通路调节着这两个种群。了解癌症干细胞的生物学特性将有助于鉴定对未来治疗重要的分子靶标。