Kondratova V N, Botezatu I V, Shelepov V P, Likhtenshtein A V
Mol Biol (Mosk). 2014 Nov-Dec;48(6):999-1007.
A recent study of human normal and tumor tissues revealed a high transcriptional activity of pericentromeric satellite DNA repeats (they produce half of all transcripts in tumor cells that is many times higher than in normal ones). It was found also that the two subtypes of satellite DNA (HSATII and GSATII) are transcribed reciprocally, i.e. there is a sharp prevalence of HSATII transcription in tumors, while GSATII transcription prevails in the corresponding normal tissues. As different RNAs are present in blood plasma, and some of them serve as effectivetumor markers, we attempted for the first time to evaluate satellite HSATII and GSATII RNAs in the blood plasma of healthy donors and cancer patients. The RT-PCR protocol designed for this purpose allowed us to detect transcripts of both HSATII and GSATII repeats. As it has been shown, HSATII transcripts are more abundant than GSATII ones in plasma of healthy donors and vice versa in plasma of cancer patients; these ratios being diametrically opposed to those that exist within the cells. Some suggestions concerning origins of circulating satellite RNAs and their probable role as tumor markers are discussed.
最近一项针对人类正常组织和肿瘤组织的研究发现，着丝粒周围卫星DNA重复序列具有很高的转录活性（它们产生的转录本占肿瘤细胞中所有转录本的一半，这一比例比正常细胞中高出许多倍）。研究还发现，卫星DNA的两种亚型（HSATII和GSATII）相互转录，即HSATII转录在肿瘤中占主导地位，而GSATII转录在相应的正常组织中占主导地位。由于血浆中存在不同的RNA，其中一些可作为有效的肿瘤标志物，我们首次尝试评估健康供体和癌症患者血浆中的卫星HSATII和GSATII RNA。为此设计的RT-PCR方案使我们能够检测HSATII和GSATII重复序列的转录本。结果表明，健康供体血浆中HSATII转录本比GSATII转录本更丰富，而在癌症患者血浆中则相反；这些比例与细胞内的比例完全相反。文中还讨论了关于循环卫星RNA的起源及其作为肿瘤标志物的可能作用的一些观点。
