[Expression and its clinical significance of miR-155 in human primary breast cancer].
OBJECTIVE
To investigate the expression of the miR-155 in human primary breast cancer and its clinical significance.


METHODS
From February to June 2009, 45 pairs of specimens of human primary breast cancer and matched nontumor breast tissues were collected from the patients who received operation for breast cancer. Real-time polymerase chain reaction (RT-PCR) was used to detect the miR-155 expression in those specimens.


RESULTS
The stem-loop RT-PCR was sensitive and specific enough to detect the expression of the miR-155. The median relative expression of miR-155 was 0.360 in tumor samples, and it was 0.135 in matched nontumor breast tissues, the difference was statistically significant (P < 0.05). It's indicated that the up-regulation of miR-155 expression was associated with advanced TNM clinical stage (median 0.316, 0.358 and 0.417 respectively for stage I, II and III tumor, P = 0.002), lymph node metastasis (median 0.383 and 0.355 respectively for cases with positive and negative lymph nodes, P = 0.034), higher proliferation index [median 0.387 and 0.353 respectively for cases with high proliferation index (Ki67 > 10%) and low proliferation index (Ki67 ≤ 10%), P = 0.019], estrogen receptor-positive (0.367 and 0.318 respectively for cases with positive estrogen receptor and negative group, P = 0.041) and progesterone receptor-positive (0.398 and 0.335 respectively for cases with positive progesterone receptor and negative group, P = 0.029) in patients with breast cancer.


CONCLUSIONS
The expression of miR-155 is up-regulated in primary breast cancer, especially in patients with positive estrogen and progesterone receptor. miR-155 may play an important role in the proliferation, invasion and metastasis of human primary breast cancer, and it could be a indicator in the diagnosis and prognosis of primary breast cancer.
Zhu
Jin
J
Department of Surgical Oncology, the First Affiliated Hospital of Wenzhou Medical College, Wenzhou, China.
Hu
Xiao-qu
XQ
Guo
Gui-long
GL
Zhang
Yin
Y
Wang
Ou-chen
OC
You
Jie
J
Huang
Qi-di
QD
Zhang
Xiao-hua
XH
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D047628:Estrogen Receptor alpha / Q000378:metabolism; D005260:Female; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D011980:Receptors, Progesterone / Q000378:metabolism
C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; C524942:MIRN155 microRNA, human; D035683:MicroRNAs; D011980:Receptors, Progesterone