Mechanisms of Cellular Senescence Group, Institute of Cytology of the Russian Academy of Sciences, Tikhoretsky Ave. 4, 194064 Saint-Petersburg, Russia.
Laboratory of Intracellular Membranes Dynamic, Institute of Cytology of the Russian Academy of Sciences, Tikhoretsky Ave. 4, 194064 Saint-Petersburg, Russia.
Int J Mol Sci. 2023 Sep 14;24(18):14089. doi: 10.3390/ijms241814089.
Being the major cellular component of highly dynamic tissue, endometrial stromal cells (EnSCs) are exposed to cycles of proliferation upon hormonal stimulation, which might pose risks for the accumulation of mutations and malignization. However, endometrial stromal tumors are rare and uncommon. The present study uncovered defense mechanisms that might underlie the resistance of EnSCs against oncogenic transformation. All experiments were performed in vitro using the following methods: FACS, WB, RT-PCR, IF, molecular cloning, lentiviral transduction, and CRISPR/Cas9 genome editing. We revealed that the expression of the mutant HRAS leads to EnSC senescence. We experimentally confirmed the inability of HRAS-expressing EnSCs to bypass senescence and resume proliferation, even upon estrogen stimulation. At the molecular level, the induction of oncogene-induced senescence (OIS) was accompanied by activation of the MEK/ERK, PI3K/AKT, p53/p21/Rb, and p38/p16/Rb pathways; however, inhibiting either pathway did not prevent cell cycle arrest. PTEN loss was established as an additional feature of HRAS-induced senescence in EnSCs. Using CRISPR-Cas9-mediated PTEN knockout, we identified PTEN loss-induced senescence as a reserve molecular mechanism to prevent the transformation of HRAS-expressing EnSCs. The present study highlights oncogene-induced senescence as an antitumor defense mechanism of EnSCs controlled by multiple backup molecular pathways.
作为高度动态组织的主要细胞成分，子宫内膜基质细胞（EnSCs）在激素刺激下经历增殖周期，这可能会增加突变和恶性转化的风险。然而，子宫内膜基质肿瘤非常罕见。本研究揭示了可能使 EnSCs 抵抗致癌转化的防御机制。所有实验均在体外进行，使用以下方法：FACS、WB、RT-PCR、IF、分子克隆、慢病毒转导和 CRISPR/Cas9 基因组编辑。我们发现突变型 HRAS 的表达导致 EnSC 衰老。我们通过实验证实，即使在雌激素刺激下，表达 HRAS 的 EnSCs 也无法绕过衰老并恢复增殖。在分子水平上，癌基因诱导的衰老（OIS）的诱导伴随着 MEK/ERK、PI3K/AKT、p53/p21/Rb 和 p38/p16/Rb 途径的激活；然而，抑制任何一条途径都不能阻止细胞周期停滞。PTEN 缺失被确定为 HRAS 诱导的 EnSCs 衰老的另一个特征。通过 CRISPR-Cas9 介导的 PTEN 敲除，我们确定了 PTEN 缺失诱导的衰老作为一种储备分子机制，可防止表达 HRAS 的 EnSCs 发生转化。本研究强调了癌基因诱导的衰老作为 EnSCs 的抗肿瘤防御机制，受多种后备分子途径的控制。
