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Figure 1 | BMC Cancer

Figure 1

From: Epigenetic silencing of miR-375 induces trastuzumab resistance in HER2-positive breast cancer by targeting IGF1R

Figure 1

Trastuzumab-resistant and parental breast cancer SKBr-3 cells display distinct characteristics and miRNA expression profiles. A. SKBr-3 cells were cultured in the presence of trastuzumab (5 μg/ml) for 6 months to obtain resistant cells. A colony formation assay in soft agar was performed using parental and resistant cells. The images are representative of triplicate experiments on day 7 after cell seeding. B. MTT assays of parental and trastuzumab-resistant SKBr-3 cells in the absence of trastuzumab. C. Confirmation of the differential expression of the indicated miRNAs by qRT-PCR. Each assay was performed in triplicate and the expression levels of each miRNA were normalized to those of snRNA RNU6B (U6). D. The predicted human miR-375 binding site at nucleotides 2993-2999 of the 3′ UTR of wild-type (WT) IGF1R (sense). The sequence of the pGL3-IGF1R-mut construct containing mutated nucleotides at the miR-375 binding site within the 3′ UTR of IGF1R is also shown. All data are represented as the mean ± SD or are representative of n = 3 replicates. *P <0.05, **P <0.01 and ***P <0.001.

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