Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
Arch Gynecol Obstet. 2015 Jul;292(1):225-9. doi: 10.1007/s00404-014-3596-7. Epub 2014 Dec 24.
K-Ras transcripts comprise two main isoforms: K-Ras 4A and K-Ras 4B, which act differently. The expression of both isoforms was reported in many human tissues. However, K-Ras 4B was the major expressed transcript variant. An increased expression of K-Ras 4B mRNA was reported in eutopic endometrium of endometriosis patients. In this way, we aimed to study the expression of K-Ras 4A transcript in eutopic endometrium related to endometriosis.
Employing exon4-flanking primers, K-Ras isoforms were simultaneously amplified in a RT-PCR reaction. Quantitative real-time PCR was performed using GAPDH as an internal control. K-Ras 4A transcript expression in eutopic endometrium was analyzed by ΔΔC T method.
We identified existence of both of K-Ras 4A and K-Ras 4B in eutopic endometrium of patients and controls. Quantitative real-time analysis demonstrated that K-Ras 4A expression was 2.7-fold higher in endometriosis than non-endometriosis eutopic samples. Interestingly, this overexpression mainly occurs through the proliferative phase of menstrual cycle.
The findings bring to light the eminent role of K-Ras 4A in endometriosis. This splice variant which is known for promoting apoptosis could be an effective factor in balance between proliferation and death of eutopic endometrial cells.
K-Ras 转录本包含两种主要的异构体：K-Ras 4A 和 K-Ras 4B，它们的作用不同。这两种异构体在许多人体组织中都有表达。然而，K-Ras 4B 是主要表达的转录变体。有报道称，子宫内膜异位症患者的在位子宫内膜中 K-Ras 4B mRNA 的表达增加。通过这种方式，我们旨在研究与子宫内膜异位症相关的在位子宫内膜中 K-Ras 4A 转录本的表达。
采用外显子 4 侧翼引物，在 RT-PCR 反应中同时扩增 K-Ras 异构体。使用 GAPDH 作为内参进行实时定量 PCR。采用 ΔΔC T 法分析在位子宫内膜中 K-Ras 4A 转录本的表达。
我们在患者和对照组的在位子宫内膜中鉴定出了 K-Ras 4A 和 K-Ras 4B 的存在。实时定量分析表明，子宫内膜异位症组中 K-Ras 4A 的表达比非子宫内膜异位症组在位样本高 2.7 倍。有趣的是，这种过表达主要发生在月经周期的增殖期。
这些发现揭示了 K-Ras 4A 在子宫内膜异位症中的重要作用。这种已知促进细胞凋亡的剪接变体可能是在位子宫内膜细胞增殖和死亡平衡的有效因素。
