High expression of microRNA-210 is an independent factor indicating a poor prognosis in Japanese triple-negative breast cancer patients.
OBJECTIVE
MicroRNAs have emerged as a new class of non-coding genes involved in regulating cell proliferation, differentiation and viability. Recent studies have identified miR-210 as one of a set of hypoxia-regulated microRNAs and demonstrated a direct regulatory role of HIF-1 alpha for its transcription. Here, we assessed miR-210 expression in Japanese triple-negative breast cancers and determined its clinical significance.


METHODS
TaqMan MicroRNA assays for miR-210 expression were performed on 161 samples of Japanese breast cancer tissue (58 triple-negative breast cancer and 103 estrogen receptor positive/HER2 negative). Correlations between miR-210 expression and clinicopathological factors were analyzed. The effects of several variables on survival were tested by a Cox proportional hazards regression analysis.


RESULTS
miR-210 expression in triple-negative breast cancers was significantly higher than in estrogen receptor-positive/HER2-negative breast cancers (P < 0.001). Patients whose triple-negative breast cancers showed low miR-210 expression experienced significantly better disease-free and overall survival than those with high miR-210 expression (P = 0.02 and P = 0.05, respectively). Although the prognosis of patients with triple-negative breast cancers is poor, Cox univariate and multivariate analyses demonstrated that a higher expression of miR-210 was an independent factor indicating a worse prognosis than for patients with a low level of miR-210.


CONCLUSIONS
The degree of miR-210 expression might be a clinically useful prognostic factor for decision-making regarding treatment in the adjuvant setting, especially in node-negative triple-negative breast cancer patients.
Department of Oncology, Immunology and Surgery, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan. toyamat-ncu@umin.ac.jp
Tatsuya
T
Toyama
Naoto
N
Kondo
Yumi
Y
Endo
Hiroshi
H
Sugiura
Nobuyasu
N
Yoshimoto
Mai
M
Iwasa
Satoru
S
Takahashi
Yoshitaka
Y
Fujii
Hiroko
H
Yamashita
D044466:Asian People; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000378:metabolism / Q000401:mortality; D018572:Disease-Free Survival; D039621:Eukaryotic Initiation Factor-3 / Q000032:analysis; D005260:Female; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism*; D008875:Middle Aged; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism
D039621:Eukaryotic Initiation Factor-3; D035683:MicroRNAs; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C105988:EIF3A protein, human; C543800:MIRN210 microRNA, human