Differential microRNA expression profiles in tamoxifen-resistant human breast cancer cell lines induced by two methods.

Differential microRNA expression profiles in tamoxifen-resistant human breast cancer cell lines induced by two methods. Oncol Lett. 2018 Mar;15(3):3532-3539 Authors: Ye P, Fang C, Zeng H, Shi Y, Pan Z, An N, He K, Zhang L, Long X Abstract Tamoxifen (TAM) resistance has become a severe problem for endocrine therapy of breast cancer. The present study investigated the association between microRNA (miRNA) expression and TAM resistance in breast cancer. The TAM-resistant breast cancer MCF-7C and MCF-7T cell lines were established using the human breast cancer cell line MCF-7 as the parental cell line and 4-hydroxytamoxifen (OHT) as the screening drug in vitro. The MCF-7C cell line was established by dose stepwise induction beginning with a low concentration of OHT; the MCF-7T cell line was established by temporal stepwise induction beginning with a high concentration of OHT. Differential miRNA expression profiles between TAM-sensitive (MCF-7) and TAM-resistant (MCF-7C and MCF-7T) breast cancer cell lines were detected and analyzed using RNA sequencing technology. The results of western blot analysis indicated that the level of ERĪ± protein expression in drug-resistant cells was significantly increased. A total of 1,646 miRNAs were detected in all samples, including 1,376 known miRNAs and 270 predicted miRNAs. There were 118 miRNAs expressed at significantly different levels between MCF-7C and MCF-7 cells (P<0.05); among them, 67 miRNA...
Source: Oncology Letters - Category: Cancer & Oncology Tags: Oncol Lett Source Type: research