結論：本研究中發現 miR-21、HER-2/neu 及 PTEN 之高表現與乳癌患者復發有關，但並不影響其下游PTEN的表現，因此可能有其他路徑參與miR-21所調控的乳癌致病過程，但仍需進一步研究。 Objective：Over the last decade, the incidence of breast cancer increased year by year, and the mortality rate is the top of female cancer in Taiwan. Previous study showed that overexpression of miR-21 was associated with recurrence in breast cancer. The aim of this study was to analyze the association of miR-21 expression and clinic pathologic data and to investigate whether the affect of miR-21 through PTEN pathway.
Materials and Methods：A total of 120 female breast cancer patients, who were enrolled at a single medical center in Taichung. MiR-21, PTEN, hormone receptor (Estrogen receptor、Progesterone receptor) and HER-2 (Human Epidermal Growth Factor Receptor 2) receptor were analyzed by quantitative RT-PCR. The function of invasion and migration of three breast cancer cell lines (T-47D, MDA-MB-231 and MCF-7) were analyzed by invasion、migration and wound healing assay.
Results：Our data showed that no any significantly difference was found between miR-21 and PTEN. MiR-21 expression was positive correlated with HER-2/neu mRNA levels (P=0.038). Patients with high miR-21 had poor disease-free survival (p=0.047) compared with low miR-21 expression patients. In addition, patients with high PTEN expression had poor disease-free survival (P=0.024). We also found that patients with miR-21 high/ HER-2/neu high or miR-21 high/ PTEN high had poor disease-free survival (miR-21/HER-2/neu, p=0.009; miR-21/PTEN, p=0.003). Thus, we suggested that the expressions of miR-21, HER-2/neu and PTEN play important roles in prognosis and associated with recurrence in breast cancer. These results were also confirmed in cell model experiments.
Conclusion：In this study, we found that the expression of miR-21, HER-2/neu, and PTEN were associated with the recurrence of breast cancer. Thus, we suggested that the other pathways maybe involved in miR-21 mediated pathogenesis of breast cancer.
