[Expression of microRNA-21 in invasive ductal carcinoma of the breast and its association with phosphatase and tensin homolog deleted from chromosome expression and clinicopathologic features].
OBJECTIVE
To investigate the expression of microRNA-21 (mir-21) in invasive ductal carcinoma (IDC) of the breast and its association with phosphatase and tensin homologue deleted from chromosome (PTEN)-10 protein expression and the clinicopathologic features of IDC.


METHODS
Specimens of IDC and normal tissues more than 5 cm away from the tumor tissues were collected from 40 IDC patients, all female, aged 53 (35-77). Stem-loop real-time RT-PCR was used to examine the mir-21 expression. Immunohistochemistry was used to examine the PTEN protein expression in the tumor tissue. The association of mir-21 expression with the PTEN expression and the clinicopathologic features of the breast IDC were analyzed.


RESULTS
Compared with the nontumor control samples, the median (M) of relative expression of mir-21 (2(-DeltadeltaCt)) was 5.770 (25th-75th percentile, 3.605-7.255) in the tumor samples, significantly higher than that of the nontumor control samples (set at 1.000, P<0.001). Reduced PTEN protein expression was seen in 45% (18/22) of all cases. The expression of mir-21 was higher in the group of reduced PTEN expression (with an M of 6.800) than in the group of high PTEN expression (with an M of 4.850, P=0.013). The up-regulated expression of mir-21 was positively correlated with the TNM clinical stage, lymph node positivity, and proliferation index (P=0.021, 0.010, and 0.030 respectively).


CONCLUSIONS
mir-21 plays an important role in the development and progression of breast cancer. PTEN is possibly one of the targets of mir-21.
Huang
Guan-li
GL
Department of Surgical Oncology, First Affiliated Hospital of Wenzhou Medical College, Wenzhou 325000, China.
Zhang
Xiao-hua
XH
Guo
Gui-long
GL
Huang
Ka-te
KT
Yang
Kai-yan
KY
Hu
Xiao-qu
XQ
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D005260:Female; D015870:Gene Expression; D006801:Humans; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D051059:PTEN Phosphohydrolase / Q000235:genetics*
C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human