Abstract 1470: The association of miR-21, HER-2/neu, and PTEN expression and clinical outcome of breast cancer

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA 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 effect 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 four breast cancer cell lines (T-47D, MDA-MB-231, MCF-7 and BT-474) were analyzed by invasion and migration assay and wound healing assay. Results: Our data showed that no 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 level had poor disease-free survival (p=0.047) compared with low miR-21 level patients. In addition, patients with high PTEN level 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 in Taiwan. Thus, we suggested that the other pathways maybe involved in miR-21 mediated pathogenesis of breast cancer. Citation Format: Hsiao-Ching Lin, Ya-Wen Cheng, Nan-Yung Hsu. The association of miR-21, HER-2/neu, and PTEN expression and clinical outcome of breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1470. doi:10.1158/1538-7445.AM2014-1470