Analysis of the purified RNA samples to confirm that Notch pathway activation inhibits apoptosis in uterine leiomyomas leading to fibroid growth

Uterine leiomyomas are the most common benign tumor in humans causing significant morbidity with vaginal bleeding, pelvic pressure and pain. Histologically, leiomyomas show a large degree of extracellular matrix disorganization. I am working with a colleague who recently found Notch pathway gene expression were clearly altered in fibroids (“Differential expression of the Notch signal transduction pathway: ligands, receptors and Numb in uterine leiomyomas vs. myometrium,” G. Christman, H. Tang, I. Ahmad, J. Stribley, Fertility and Sterility, Volume 88, Supp 1, S72, September 2007). Glycosaminoglycan expression was found to be over-expressed in uterine leiomyomas compared to myometrial samples (Fertility and Sterility, Vol 88 Supp 1, S106, September, 2007), but glycosyltransferase and glycosidase expression has not been reported. We have purified RNA samples from paired uterine leiomyoma and normal myometrium from a previous clinical study. Dr. Domino's laboratory hypothesis is that Notch pathway activation inhibits apoptosis in uterine leiomyomas leading to fibroid growth. Notch ligands are fucosylated glycans. The bulk of a fibroid is the extracellular matrix yet little has been studied on leiomyocyte expression of enzymes that model glycans in the extracellular matrix. RNA preparations of paired samples of excess human tissues from hysterectomies, with two different groups normal myometrium, and leiomyoma tumors were sent to Microarray Core (E). The RNA was amplified, labeled, and hybridized to GLYCO_v3 microarrays.

子宫平滑肌瘤是人类最常见的良性肿瘤，可引发阴道出血、盆腔压迫与疼痛，导致显著的疾病负担。组织学上，平滑肌瘤表现为细胞外基质（extracellular matrix, ECM）的严重紊乱。笔者与合作者近期发现，肌瘤组织中Notch通路基因的表达存在显著改变（引用文献：G. Christman、H. Tang、I. Ahmad、J. Stribley所著《子宫平滑肌瘤与子宫肌层中Notch信号通路配体、受体及Numb的差异表达》，《生育与不孕》，2007年9月，第88卷增刊1，S72页）。另有研究显示，与子宫肌层样本相比，子宫平滑肌瘤中糖胺聚糖（glycosaminoglycan, GAG）的表达水平显著上调（《生育与不孕》，2007年9月，第88卷增刊1，S106页），但目前尚未见糖基转移酶与糖苷酶的表达相关报道。本研究团队已从一项既往临床研究中获取了配对的子宫平滑肌瘤与正常子宫肌层组织的纯化RNA样本。多米诺（Domino）实验室提出的研究假说为：Notch通路的激活可抑制子宫平滑肌瘤细胞的凋亡，进而促进肌瘤生长。Notch配体属于岩藻糖基化聚糖。肌瘤的主体成分为细胞外基质，但目前针对平滑肌瘤细胞表达细胞外基质聚糖修饰相关酶类的研究仍十分匮乏。本研究将两组配对的子宫切除术后剩余人类组织样本（分别为正常子宫肌层与子宫平滑肌瘤组织）的RNA制备物送至微阵列核心实验室（E）进行检测。上述RNA均经过扩增、标记，并与GLYCO_v3微阵列芯片进行杂交。