Identification of metastasis-associated microRNAs in serum from rectal cancer patients

Robin Mjelle; Kjersti Sellæg; Pål Sætrom; Liv Thommesen; Wenche Sjursen; Eva Hofsli

doi:10.18632/oncotarget.21412

Identification of metastasis-associated microRNAs in serum from rectal cancer patients

Oncotarget. 2017 Sep 30;8(52):90077-90089. doi: 10.18632/oncotarget.21412. eCollection 2017 Oct 27.

Authors

Robin Mjelle¹, Kjersti Sellæg¹, Pål Sætrom^{1

2}, Liv Thommesen³, Wenche Sjursen^{1

4}, Eva Hofsli^{1

5}

Affiliations

¹ Department of Clinical and Molecular Medicine, NO-7491 Trondheim, Norway.
² Department of Computer Science, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
³ Department of Biomedical Science, Norwegian University of Science and Technology, 7030 Trondheim Norway.
⁴ Department of Medical Genetics, St. Olavs Hospital, Norwegian University of Science and Technology, 7030 Trondheim Norway.
⁵ The Cancer Clinic, St. Olavs Hospital, Trondheim University Hospital, 7030 Trondheim, Norway.

Abstract

MicroRNAs (miRNAs) are promising prognostic and diagnostic biomarkers due to their high stability in blood. Here we investigate the expression of miRNAs and other noncoding (nc) RNAs in serum of rectal cancer patients. Serum from 96 rectal cancer patients was profiled using small RNA sequencing and expression of small RNAs was correlated with the clinicopathological characteristics of the patients. Multiple classes of RNAs were detected, including miRNAs and fragments of tRNAs, snoRNAs, long ncRNAs, and other classes of RNAs. Several miRNAs, miRNA variants (isomiRs) and other ncRNAs were differentially expressed between Stage IV and Stage I-III rectal cancer patients, including several members of the miR-320 family. Furthermore, we show that high expression of miR-320d as well as one tRNA fragment is associated with poor survival. We also show that several miRNAs and isomiRs are differentially expressed between patients receiving preoperative chemoradiotherapy and patients who did not receive any treatment before serum collection. In summary, our study shows that the expression of miRNAs and other small ncRNAs in serum may be used to predict distant metastasis and survival in rectal cancer.

Keywords: biomarker; isomiR; microRNA; rectal cancer; serum.