Department of Tumor Immunology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500HB, Nijmegen, The Netherlands.
Cell Oncol (Dordr). 2013 Oct;36(5):363-74. doi: 10.1007/s13402-013-0142-8. Epub 2013 Aug 9.
The aim of this study was to examine the expression of established stem cell markers in ascites and tumor tissue obtained from ovarian cancer patients.
Mononuclear cells present in ascites were collected by density gradient centrifugation. Intracellular flowcytometry was used to assess the putative presence of stem cell markers. RT-PCR was used to detect full length Oct4A, a splice variant Oct4B, implicated in glioma and breast cancer, Oct4 pseudogenes and c-Myc. Genes were cloned and sequenced to determine putative mutations. Confocal laser scanning microscopy was performed to localize the markers in ascites cells as well as in tumor tissue. Material from carcinomas other than epithelial ovarian carcinoma served as control.
A small quantity of cells in ascites and in tumor tissue of ovarian cancer patients was detected that expresses c-Myc, Oct4A and Nanog. Besides Oct4A, present in the nucleus, also the cytoplasmic resident Oct4B splice variant was detected. Remarkably, c-Myc was found partially in the cytoplasm. Since no mutations in c-Myc were found that could explain the cytoplasmic localization, we hypothesize that this is due an IL-6 induced c-Myc shuttle factor.
The expression of stem cell genes was detected in a small proportion of tumor cells present in ascites as well as in tumor tissue. IL-6 plays an important role in the induction of c-Myc.
本研究旨在检测从卵巢癌患者的腹水和肿瘤组织中获得的已确立的干细胞标志物的表达。
通过密度梯度离心收集腹水单核细胞。使用细胞内流式细胞术评估干细胞标志物的存在。使用 RT-PCR 检测全长 Oct4A、与神经胶质瘤和乳腺癌相关的剪接变体 Oct4B、Oct4 假基因和 c-Myc。克隆和测序基因以确定可能的突变。使用共聚焦激光扫描显微镜在腹水细胞和肿瘤组织中定位标志物。上皮性卵巢癌以外的癌组织作为对照。
在卵巢癌患者的腹水中和肿瘤组织中检测到少量表达 c-Myc、Oct4A 和 Nanog 的细胞。除了存在于核中的 Oct4A 外，还检测到细胞质驻留的 Oct4B 剪接变体。值得注意的是，c-Myc 部分存在于细胞质中。由于未发现可解释细胞质定位的 c-Myc 突变，我们假设这是由于 IL-6 诱导的 c-Myc 穿梭因子所致。
在腹水和肿瘤组织中存在的少量肿瘤细胞中检测到干细胞基因的表达。IL-6 在诱导 c-Myc 中起重要作用。
