干细胞不均匀分裂与肿瘤发生

The asymmetric division and tumorigenesis of stem cells

干细胞可以通过不均匀分裂和均匀分裂两种模式产生后代,均匀分裂产生两个相同的子代干细胞;不均匀分裂产生的子代细胞中一个趋向分化,另一个保持自我更新的能力。干细胞不均匀分裂机制的失调可能导致肿瘤细胞的出现。干细胞的不均匀分裂受细胞极性因子、细胞命运决定因子及纺锤体的调节,这些因子突变或失调均可导致细胞的恶性转化。因此,深入探讨干细胞的分裂模式以及干细胞-肿瘤干细胞-肿瘤细胞之间的关系将成为今后肿瘤研究的重要方向。这些领域的深入研究将为肿瘤的耐药性、复发和转移等问题提供新的解决途径。

Stem cells use asymmetric and symmetric cell division to generate progeny. Symmetric cell division is defined as the generation of daughter cells that are destined to acquire the same fate. Stem cells divide asymmetrically to generate one daughter with a stem-cell fate and one daughter with different fate. Disruption of the machinery that regulates asymmetric division may be a reason for the generation of cancer. The asymmetric mechanism is maintained by cell polarity factors,cell fate determinants,and the spindle apparatus. The mutation or dysregulation of these factors may change stem cells from asymmetric to symmetric cell division,then leading to tumorigenesis. Therefore,further study is needed on the mechanisms of stem cell control between asymmetric and symmetric cell division,as well as the relationships among stem cells,cancer stem cells,and tumor cells. It may bring us a new approach for the resistance,recurrence,and metastasis of tumors.