Abstract 968: Circulating microRNA-1290 as a novel diagnostic and prognostic biomarker in human colorectal cancer
Authors: Toiyama Yuji , Imaoka Hiroki , Fujikawa Hiroyuki , Hiro Junichiro , Saigusa Susumu , Tanaka Koji , Inoue Yasuhiro , Mohri Yasuhiko , Mori Takao , Kato Toshio , Goel Ajay , Kusunoki Masato 
Published: July 2016

Abstract
Background & Aims:
MicroRNAs (miRNAs) play a crucial role in diverse cellular biological processes such as differentiation, proliferation, migration, invasion and survival. MiRNA expression patterns are found to be frequently dysregulated in human tumors, which is currently being exploited both from a basic science perspective and for its clinical usefulness as disease biomarkers. Circulating miRNAs are attracting major interest as potential noninvasive biomarkers for colorectal cancer (CRC). This study aimed to identify a novel serum miRNA biomarker for the early detection and/or evaluating prognosis of CRC patients.
Methods:
Comprehensive miRNA array analysis was performed using serum samples from patients with colorectal neoplasia (CRC: n = 3, adenoma: n = 3) and healthy controls (n = 3). Next, to verify whether the candidate miRNA possessed a secretory potential, we screened miRNA expression levels in culture medium from 2 CRC cell lines, followed by serum analysis from 12 stage IV CRC, 12 adenoma and 12 control subjects. Thereafter, we validated expression of candidate miRNAs in 179 primary CRC tissues, as well as serum samples from an independent cohort of 211 CRCs, 56 adenomas, and 57 control subjects.
Results:
Through microarray analysis, we identified significantly higher levels of miRNA-1290 (miR-1290) in serum from patients with colorectal adenomas and cancers. We verified miR-1290 overexpression in serum of CRC patients in a training cohort. In the validation cohort, serum miR-1290 levels were significantly upregulated in patients with colorectal adenomas (P &lt; 0.0001) and cancers (P &lt; 0.0001). Serum miR-1290 levels could robustly distinguish adenoma (area under the curve [AUC] = 0.718) and CRC patients (AUC = 0.830) from normal subjects. Serum miR-1290 levels significantly diminished after surgical resection of the primary tumor in the same patients’ serum specimens (P &lt; 0.0001). In addition, we observed a statistically significant positive correlation of miR-1290 expression levels between primary CRC tissues and matched serum samples (ρ = 0.482; P &lt; 0.0001). High miR-1290 expression in serum and tissue was significantly associated with tumor aggressiveness and poor prognosis. Moreover, serum miR-1290 levels were an independent prognostic factor in CRC patients (hazard ratio = 4.51; 95% confidence interval = 1.23-23.69; P = 0.0096).
Conclusions:
Serum miR-1290, which might be secreted from primary CRC, is a novel diagnostic and prognostic biomarker in CRC.
Citation Format: Yuji Toiyama, Hiroki Imaoka, Hiroyuki Fujikawa, Junichiro Hiro, Susumu Saigusa, Koji Tanaka, Yasuhiro Inoue, Yasuhiko Mohri, Takao Mori, Toshio Kato, Ajay Goel, Masato Kusunoki. Circulating microRNA-1290 as a novel diagnostic and prognostic biomarker in human colorectal cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 968.