Fig. 1

Identification of Trastuzumab-resistant associated circRNA (circCDYL2) in breast cancer after anti-HER2 therapy. A circRNA expression profile in breast cancer patients with Trastuzumab sensitive and resistant by circRNAs deep sequencing. R, trastuzumab-resistant patient & S, trastuzumab-sensitive patient. B Quantitative analysis of circCDYL2 expression in HER2⁺ cancer tissues with trastuzumab sensitive (n = 16) and trastuzumab resistant (n = 55) by qRT-PCR. C The origin of circCDYL2. D The expression of circCDYL2 in different breast cancer patient tissues by ISH. HR, hormone receptor. Scale bar, 100 μm. E Representative images of circCDYL2 by ISH and Ki67, P-AKT, AKT, P-ERK and ERK by IHC. Scale bar, 50 μm. F Kaplan-Meier analysis of the correlation between circCDYL2 expression and disease-free survival (DFS). All of the 127 HER2⁺ BC patients were received standard trastuzumab therapy. G Kaplan-Meier analysis of the correlation between circCDYL2 expression and overall survival (OS). H The relationship of expression between circCDYL2 and Ki67. I The relationship of expression between circCDYL2 and P-AKT, AKT, P-ERK and ERK. All experiments were repeated at least 3 times. *P < 0.05, **P < 0.01, ***P < 0.005. Error bars indicate Standard Error of Mean (S.E.M)