Harkins Shannon K, Skalski Hilary J, Bennett Abigail Z, Pavliscak Laura, Arendt Amelia R, Wood Lauren, Moldovan Genna E, Chandler Ronald L
Department of Obstetrics, Gynecology, and Reproductive Biology, College of Human Medicine, Michigan State University, Grand Rapids, MI 49503, USA.
bioRxiv. 2025 Jun 8:2025.06.05.658183. doi: 10.1101/2025.06.05.658183.
Chromatin remodeling plays an integral part in endometrial homeostasis, having roles in the maintenance of cell identity, epithelial integrity, and prevention of endometrial disease. Chromodomain-helicase-DNA-binding protein 4 () is a chromatin remodeling protein and member of the NuRD complex, which predominantly represses transcription. is mutated in endometrial carcinoma, with most mutations leading to loss of function. has been identified as a tumor suppressor and regulator of stemness in endometrial carcinoma cells, but little is known about the tissue-specific roles of in the endometrial epithelia We generated a conditional floxed allele and combined it with to drive loss in the endometrial epithelium. Consistent with previous reports, expression is absent in the oviducts, ovaries, and kidneys, and it shows variegated expression within the endometrial epithelium. Loss of CHD4 was confirmed by immunohistochemistry, and stained cells were quantified to determine the percentage of endometrial epithelial cells with and without CHD4. Compared to the glandular epithelium, the extent of CHD4 loss was higher in the luminal epithelium and unaffected by age. Mice with conditional knockout of had normal endometrial histology. A 6-month breeding trial was performed to assess the functional effects of endometrial epithelial loss on fertility. No difference in litter size, mean number of pups per litter per dam, or pup weight was found between genotypes. These findings demonstrate that conditional loss using is not sufficient to alter the structure and function of the endometrial epithelium or drive tumorigenesis. As is frequently co-mutated with other cancer driver genes such as , , and , future mouse modeling efforts emulating patient mutational profiles might provide insight into the role of in endometrial carcinoma.
染色质重塑在子宫内膜稳态中起着不可或缺的作用，在维持细胞特性、上皮完整性以及预防子宫内膜疾病方面发挥作用。染色质结构域解旋酶DNA结合蛋白4（CHD4）是一种染色质重塑蛋白，也是核小体改造去乙酰化酶（NuRD）复合物的成员，主要抑制转录。CHD4在子宫内膜癌中发生突变，大多数突变导致功能丧失。CHD4已被确定为子宫内膜癌细胞中的肿瘤抑制因子和干性调节因子，但关于CHD4在子宫内膜上皮中的组织特异性作用知之甚少。我们构建了一个条件性CHD4基因敲除等位基因，并将其与Wnt1-Cre相结合，以驱动子宫内膜上皮细胞中CHD4缺失。与之前的报道一致，CHD4在输卵管、卵巢和肾脏中不表达，在子宫内膜上皮中呈斑驳表达。通过免疫组织化学证实了CHD4的缺失，并对染色细胞进行定量，以确定有和没有CHD4的子宫内膜上皮细胞的百分比。与腺上皮相比，腔上皮中CHD4的缺失程度更高，且不受年龄影响。条件性敲除CHD4的小鼠子宫内膜组织学正常。进行了一项为期6个月的繁殖试验，以评估子宫内膜上皮细胞CHD4缺失对生育能力的功能影响。在不同基因型之间，窝仔数、每只母鼠每窝幼崽的平均数量或幼崽体重均未发现差异。这些发现表明，利用Wnt1-Cre进行CHD4条件性缺失不足以改变子宫内膜上皮的结构和功能或驱动肿瘤发生。由于CHD4经常与其他癌症驱动基因如PIK3CA、KRAS和PTEN共同突变，未来模拟患者突变谱的小鼠建模研究可能会深入了解CHD4在子宫内膜癌中的作用。
