Abstract 1967: MicroRNA-1290 promotes tumor progression and acts as a novel biomarker for poor prognosis in human colorectal cancer
Authors: Nagano Yuka , Toiyama Yuji , Imaoka Hiroki , Fujikawa Hiroyuki , Hiro Junichiro , Saigusa Susumu , Kobayashi Minako , Araki Toshimitsu , Ohi Masaki , Tanaka Koji , Inoue Yasuhiro , Mohri Yasuhiko , Ishii Kenichiro , Kusunoki Masato 
Published: July 2016

Abstract
Background:
MicroRNA (miRNA)-1290 is known to activate Wnt signaling pathway and increase the reprogramming-related transcript factors c-Myc and Nanog. Additionally, miR-1290 promotes the epithelial-mesenchymal transition and interferes with cellular differentiation. Previous report demonstrated that overexpressing miR-1290 shows extensive atrophy and intestinal metaplasia of the gastric mucosa, indicating that miR-1290 is involved in the precancerous lesions of the gastric epithelial cells. However, to the best of our knowledge, miR-1290 expression pattern, its clinical significance and molecular mechanism in colorectal cancer (CRC) have not been investigated.
Materials and Methods:
We screened miR-1290 expression in a subset of 36 tissue samples from normal colonic mucosa (n = 12), adenoma (n = 12) and CRC (n = 12). Next, we further validated miR-1290 expression in a larger, independent cohort, which included normal colonic mucosa (n = 21), adenoma (n = 26) and CRC (n = 179), and investigated the clinical significance of miR-1290 in CRC. In addition, CRC cell lines were transfected with anti-miR against miR-1290 for the assessment of its function.
Results:
In screening step, miR-1290 expression stepwise increased according to adenoma-carcinoma sequence, and its expression in adenoma and CRC was significantly higher than that in normal colonic mucosa, respectively (adenoma: p&lt;0.0001, CRC: p&lt;0.0001). In validation step, we confirmed miR-1290 expression in both adenoma and CRC was significantly higher than that in normal colonic mucosa (adenoma: p&lt;0.0001, CRC: p&lt;0.0001). In addition, miR-1290 expression in CRC gradually increased according to TNM stage and significantly higher in stage IV. High expression in CRC were significantly associated with large tumor size (&gt;40mm), high grade of T stage (T3/4), lymphatic and venous invasion positive, lymph node metastasis and liver metastasis. In addition, Kaplan-Meier survival curves revealed that the CRC patients with high miR-1290 expression were significantly poorer overall survival than that with low expression, respectively (p = 0.0082). Our in vitro study demonstrated that attenuated miR-1290 expression resulted in inhibition of proliferation, invasion and migration capacity of CRC cell lines.
Conclusions:
We, for the first time, demonstrated that miR-1290 in CRC acts as onco-miRNAs that is supported by several evidences from our in vitro analysis and clinical data. MiR-1290 is significantly associated with malignant potential of CRC and can be the biomarker for predicting poor prognosis in patients with CRC.
Citation Format: Yuka Nagano, Yuji Toiyama, Hiroki Imaoka, Hiroyuki Fujikawa, Junichiro Hiro, Susumu Saigusa, Minako Kobayashi, Toshimitsu Araki, Masaki Ohi, Koji Tanaka, Yasuhiro Inoue, Yasuhiko Mohri, Kenichiro Ishii, Masato Kusunoki. MicroRNA-1290 promotes tumor progression and acts as a novel biomarker for poor prognosis 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 1967.