Division of Thoracic Cancer, West China Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, P.R. China.
Int J Oncol. 2013 Jun;42(6):2037-45. doi: 10.3892/ijo.2013.1883. Epub 2013 Apr 4.
Disruption in apoptosis are involved in cancer development and progression. Livin-β, has been identified as a critical modulator for cell death in several tumor cell lines. It was demonstrated that a truncated fragment of Livin-β (tLivin) without its N-terminal 52 amino acids is produced in cells through protein cleavage. However, the biological consequence of the cleavage remains largely ignored. In the present study, we report that tLivin exerted a pro-apoptotic effect on cells. The subcellular localization of tLivin was mainly restricted to the cytoplasm. To explore the underlying mechanism, we observed an elevated caspase-3 activity which may account for the apoptosis. Furthermore, we observed that tLivin was further cleaved into a smaller fragment in cells. This second cleavage was possibly related to activated caspase-3. The resulted C-terminal fragment (livC) was an anti-apoptotic factor. Our study may help to deepen our understanding of the role of Livin in the regulation of cell death.
凋亡失调参与癌症的发生和发展。Livin-β已被确定为几种肿瘤细胞系中细胞死亡的关键调节剂。研究表明，Livin-β的截短片段（tLivin）通过蛋白切割在细胞中产生，没有其 N 端的 52 个氨基酸。然而，切割的生物学后果在很大程度上仍被忽视。在本研究中，我们报告 tLivin 对细胞具有促凋亡作用。tLivin 的亚细胞定位主要局限于细胞质。为了探索潜在的机制，我们观察到 caspase-3 活性升高，这可能是细胞凋亡的原因。此外，我们观察到 tLivin 在细胞中进一步切割成较小的片段。这种第二次切割可能与激活的 caspase-3 有关。所得的 C 端片段（livC）是一种抗凋亡因子。我们的研究可能有助于加深我们对 Livin 在细胞死亡调控中的作用的理解。
