Corbineau Sébastien, Lassalle Bruno, Givelet Maelle, Souissi-Sarahoui Inès, Firlej Virginie, Romeo Paul Henri, Allemand Isabelle, Riou Lydia, Fouchet Pierre
CEA DRF iRCM SCSR, Laboratoire de Recherche sur la réparation et la Transcription dans les cellules Souches, UMR 967, F-92265 Fontenay-aux-Roses, France.
INSERM, UMR967, F-92265 Fontenay-aux-Roses, France.
Oncotarget. 2017 Feb 7;8(6):10050-10063. doi: 10.18632/oncotarget.14327.
The male germinal lineage, which is defined as unipotent, produces sperm through spermatogenesis. However, embryonic primordial germ cells and postnatal spermatogonial stem cells (SSCs) can change their fate and convert to pluripotency in culture when they are not controlled by the testicular microenvironment. The mechanisms underlying these reprogramming processes are poorly understood. Testicular germ cell tumors, including teratoma, share some molecular characteristics with pluripotent cells, suggesting that cancer could result from an abnormal differentiation of primordial germ cells or from an abnormal conversion of SCCs to pluripotency in the testis. Here, we investigated whether the somatic reprogramming factors Oct3/4, Sox2, Klf4 and c-Myc (OSKM) could play a role in SSCs reprogramming and induce pluripotency using a doxycycline-inducible transgenic Col1a1-4F2A-OSKM mouse model. We showed that, in contrast to somatic cells, SSCs from adult mice are resistant to this reprogramming strategy, even in combination with small molecules, hypoxia, or p53 deficiency, which were previously described to favour the conversion of somatic cells to pluripotency. This finding suggests that adult SSCs have developed specific mechanisms to repress reprogramming by OSKM factors, contributing to circumvent testicular cancer initiation events.
雄性生殖谱系被定义为单能性的,通过精子发生产生精子。然而,胚胎原始生殖细胞和出生后精原干细胞(SSCs)在不受睾丸微环境控制时,在培养中可以改变其命运并转化为多能性。这些重编程过程的潜在机制尚不清楚。睾丸生殖细胞肿瘤,包括畸胎瘤,与多能细胞具有一些分子特征,这表明癌症可能源于原始生殖细胞的异常分化或睾丸中SCCs向多能性的异常转化。在这里,我们使用强力霉素诱导的转基因Col1a1-4F2A-OSKM小鼠模型,研究了体细胞重编程因子Oct3/4、Sox2、Klf4和c-Myc(OSKM)是否能在SSCs重编程中发挥作用并诱导多能性。我们发现,与体细胞不同,成年小鼠的SSCs对这种重编程策略具有抗性,即使与小分子、缺氧或p53缺陷相结合,而这些因素先前被描述为有利于体细胞向多能性的转化。这一发现表明,成年SSCs已经发展出特定机制来抑制OSKM因子介导的重编程,有助于避免睾丸癌起始事件的发生。