DIP2C expression in breast cancer and its clinical significance

Introduction: The aim of this study was to investigate DIP2C expression in different subtypes of breast cancer tissues and cell lines and its correlation with clinicopathologic and histopathological features, in an effort to elucidate the DIP2C expression profile in breast cancer and its clinical significance. Methods: Hereby, we investigated the DIP2C expression in breast cancer tissues using TMA-IHC method and the DIP2C expression in breast cell lines using quantitative RT-PCR. Results: DIP2C displayed universal expression, being present in all the breast cancer subtypes. There were more cases that staining weakly in breast cancer tissues (n = 79/150, 52.7%) than that in fibroadenomas tissues (n = 2/18, 11.1%) and normal tissues (n = 2/20, 10.0%) (chi(2) = 21.84, P < 0.001). Within different intrinsic subtypes of breast cancer assayed by IHC expression profiles, there were less cases of the strongly staining group in basal-like subtype (n = 38/86, 44.2%) and HER-2 subtype (n = 6/24, 25.0%) than that in luminal A (14/20, 70%) and luminal B (13/20, 65%) subtypes (chi(2) = 11.77, p = 0.008). Furthermore, DIP2C expression was positive correlated with ER (chi(2) = 8.90, p = 0.003) and PR expression (chi(2) = 10.94, p = 0.001), while negative correlated with EGFR expression (chi(2) = 9.27, p = 0.002), in accordance with the results of cell lines with different subtypes. Oncomine database also confirmed that, DIP2C was expressed lower in breast cancer tissues, and could indicate prognosis. Conclusion: our data revealed DIP2C expression level decreased in breast cancer, especially in basal-like and HER-2 subtypes, and could be a valuable target for diagnosis on specific subtype of breast cancer.