病理应激损伤
由缺氧、营养匮乏、氧化及代谢失衡等引起的应激反应能够损伤细胞，催生疾病。这些应激条件刺激tRNA
halves的产生。在毒性损伤、辐射以及缺血再灌注等组织损伤动物模型中，tRNA
halves的产生与组织损伤程度呈现相关性，例如，应激导致tRNA构象改变，随后促进ANG介导的tRNA halves的产生 1。5’-halves的表达上调与病毒及立克次体感染显著相关，可能与抑制凋亡，促进细胞存活有关。tRFs&tiRNAs、主要是30-35nt长的5’ halves在非恶性肝脏中具有高的表达量，而且在慢性病毒性肝炎中表达水平迅速上升18。
生物标志物潜力
tRFs&tiRNAs的组成和数量高度依赖于细胞类型和疾病状态 20。特别的，tRNA和tRF&tiRNA类群高度富集与生物体液中，有时甚至高于miRNA的含量 13,21,22。尽管目前对体液型生物标志物的筛选主要集中在miRNA上，但是，tRFs&tiRNAs在多种体液中的高当量高稳定性，在病理过程中的广泛参与，在实体瘤和血液恶性肿瘤中的差异表达，以及在癌症病人和正常对照之间的强大分辨能力，为人们尝试开发低侵入性的、基于tRFs&tiRNAs的生物标志物开辟了广阔的前景。例如，PLS-DA分析发现tRFs&tiRNAs的表达谱能够清楚的分辨三阴(阳)性乳腺癌与正常对照 20 (图7B，C)；研究显示，不同tRFs&tiRNAs之间的比例关系能够作为一个高效的癌症无进展生存期 (PFS) 指标和诊断标志物候选者 13。
图7. (A)血浆中存在丰富的tRNA衍生片段RNA21。在PLS-DA判别分析中tRFs&tiRNAs表达谱能够清晰的分辨三阳性乳腺癌 (B)以及三阴性乳腺癌 (C)与健康对照。
如何研究tRFs&tiRNAs
康成生物的tRF&tiRNA–seq服务系统对tRF&tiRNA进行定性定量的表达谱分析，同时对tRF&tiRNA亚家族及未知tRF&tiRNA进行鉴定。借助丰富的数据和信息，那些差异表达的tRFs&tiRNAs能够被鉴定，并使用图示的方法进行下一步的深入研究
(图. 8) 。许多已经建立好的方法都和miRNA类似，例如，qPCR验证，LNA寡核苷酸基因敲除，合成的类似物进行功能获得性研究等。
图8. tRF&tiRNA下一步研究技术路线。
参考文献
1. Anderson, P. & Ivanov, P. tRNA fragments in human health and
disease. FEBS letters 588, 4297-4304, doi:10.1016/j.febslet.2014.09.001
(2014).
2. Pliatsika, V., Loher, P., Telonis, A. G. & Rigoutsos, I.
MINTbase: a framework for the interactive exploration of mitochondrial
and nuclear tRNA fragments. Bioinformatics,
doi:10.1093/bioinformatics/btw194 (2016).
3. Zheng, L. L. et al. tRF2Cancer: A web server to detect tRNA-derived
small RNA fragments (tRFs) and their expression in multiple cancers.
Nucleic acids research, doi:10.1093/nar/gkw414 (2016).
4. Gebetsberger, J., Zywicki, M., Kunzi, A. & Polacek, N.
tRNA-derived fragments target the ribosome and function as regulatory
non-coding RNA in Haloferax volcanii. Archaea 2012, 260909,
doi:10.1155/2012/260909 (2012).
5. Sobala, A. & Hutvagner, G. Small RNAs derived from the 5' end of
tRNA can inhibit protein translation in human cells. RNA Biol 10,
553-563, doi:10.4161/rna.24285 (2013).
6. Saikia, M. et al. Angiogenin-cleaved tRNA halves interact with
cytochrome c, protecting cells from apoptosis during osmotic stress.
Molecular and cellular biology 34, 2450-2463, doi:10.1128/MCB.00136-14
(2014).
7. Hanada, T. et al. CLP1 links tRNA metabolism to progressive
motor-neuron loss. Nature 495, 474-480, doi:10.1038/nature11923 (2013).
8. Chen, Q. et al. Sperm tsRNAs contribute to intergenerational
inheritance of an acquired metabolic disorder. Science 351, 397-400,
doi:10.1126/science.aad7977 (2016).
9. Sharma, U. et al. Biogenesis and function of tRNA fragments during
sperm maturation and fertilization in mammals. Science 351, 391-396,
doi:10.1126/science.aad6780 (2016).
10. Venkatesh, T., Suresh, P. S. & Tsutsumi, R. tRFs: miRNAs in
disguise. Gene 579, 133-138, doi:10.1016/j.gene.2015.12.058 (2016).
11. Goodarzi, H. et al. Endogenous tRNA-Derived Fragments Suppress
Breast Cancer Progression via YBX1 Displacement. Cell 161, 790-802,
doi:10.1016/j.cell.2015.02.053 (2015).
12. Emara, M. M. et al. Angiogenin-induced tRNA-derived stress-induced
RNAs promote stress-induced stress granule assembly. J Biol Chem 285,
10959-10968, doi:10.1074/jbc.M109.077560 (2010).
13. Olvedy, M. et al. A comprehensive repertoire of tRNA-derived
fragments in prostate cancer. Oncotarget, doi:10.18632/oncotarget.8293
(2016).
14. Maute, R. L. et al. tRNA-derived microRNA modulates proliferation
and the DNA damage response and is down-regulated in B cell lymphoma.
Proceedings of the National Academy of Sciences of the United States of
America 110, 1404-1409, doi:10.1073/pnas.1206761110 (2013).
15. Lee, Y. S., Shibata, Y., Malhotra, A. & Dutta, A. A novel class
of small RNAs: tRNA-derived RNA fragments (tRFs). Genes &
development 23, 2639-2649, doi:10.1101/gad.1837609 (2009).
16. Greenway, M. J. et al. ANG mutations segregate with familial and
'sporadic' amyotrophic lateral sclerosis. Nature genetics 38, 411-413,
doi:10.1038/ng1742 (2006).
17. van Es, M. A. et al. Angiogenin variants in Parkinson disease and
amyotrophic lateral sclerosis. Annals of neurology 70, 964-973,
doi:10.1002/ana.22611 (2011).
18. Selitsky, S. R. et al. Small tRNA-derived RNAs are increased and
more abundant than microRNAs in chronic hepatitis B and C. Scientific
reports 5, 7675, doi:10.1038/srep07675 (2015).
19. Blanco, S. et al. Aberrant methylation of tRNAs links cellular
stress to neuro-developmental disorders. The EMBO journal 33, 2020-2039,
doi:10.15252/embj.201489282 (2014).
20. Telonis, A. G. et al. Dissecting tRNA-derived fragment complexities
using personalized transcriptomes reveals novel fragment classes and
unexpected dependencies. Oncotarget 6, 24797-24822,
doi:10.18632/oncotarget.4695 (2015).
21. Dhahbi, J. M. et al. 5' tRNA halves are present as abundant
complexes in serum, concentrated in blood cells, and modulated by aging
and calorie restriction. BMC genomics 14, 298,
doi:10.1186/1471-2164-14-298 (2013).
22. Schageman, J. et al. The complete exosome workflow solution: from
isolation to characterization of RNA cargo. BioMed research
international 2013, 253957, doi:10.1155/2013/253957 (2013).
首页
