a Molecular Targets Program , James Graham Brown Cancer Center , Louisville , Kentucky.
b Department of Ophthalmology and Visual Sciences.
Cell Cycle. 2018;17(18):2221-2229. doi: 10.1080/15384101.2018.1532254. Epub 2018 Oct 13.
Cancer stem cells (CSC) are thought to be an important source of cancer cells in tumors of different origins. Mounting evidence suggests they are generated reversibly from existing cancer cells, and supply new cancer cells during tumor progression and following therapy. Elegant lineage mapping stud(ies are identifying progenitors, and in some cases differentiated cells, as targets of transformation in a variety of tumors. Recent evidence suggests resulting tumor initiating cells (TIC) might be distinct from CSC. Molecular pathways leading from cells of tumor origin to precancerous lesions and cancer cells are only beginning to be unraveled. We review a pathway where asymmetric division of precancerous cells generates TIC in a K-Ras-initiated model of lung cancer. And, we compare unexpected steps in this asymmetric division to those evident in well-studied stem cell models.
癌症干细胞（CSC）被认为是不同来源肿瘤中癌细胞的重要来源。越来越多的证据表明，它们可以从现有癌细胞中可逆地产生，并在肿瘤进展和治疗后提供新的癌细胞。精心设计的谱系追踪研究正在确定祖细胞，在某些情况下还确定了分化细胞，作为各种肿瘤转化的靶点。最近的证据表明，由此产生的肿瘤起始细胞（TIC）可能与 CSC 不同。从肿瘤起源细胞到癌前病变和癌细胞的分子途径才刚刚开始被揭示。我们回顾了一条途径，即癌前细胞的不对称分裂在 K-Ras 引发的肺癌模型中产生了 TIC。并且，我们将这种不对称分裂中的意外步骤与在研究充分的干细胞模型中出现的步骤进行了比较。
