The aim of the study is to explore roles of microRNA (miR)-124a and miR-30d in breast cancer (BC) patients with type 2 diabetes mellitus (T2DM). A total of 144 cases of confirmed diagnosed BC with T2DM, T2DM, BC, or healthy people were enrolled. Among them, BC patients with T2DM were regarded as the experiment group (n = 36), patients with T2DM as the Dm group (n = 36), patients with BC as the Bc group (n = 36), and healthy subjects as the healthy group (n = 36). The fasting insulin resistance index, glycosylated hemoglobin, and estradiol were measured. MiR-124a and miR-30d expressions were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The insulin resistance index was significantly higher in the experiment group compared to the other three groups (all P < 0.05). The glycated hemoglobin was in a normal range in the Bc group and healthy group, but was higher in the experiment group and the Bc group compared to that in the healthy group (both P < 0.05). The serum estradiol level was obviously higher in the Bc group compared with that in the Dm group and the experiment group (both P < 0.05). The expressions of miR-124a and miR-30d were positively correlated with insulin resistance index, BMI and glycosylated hemoglobin (miR-124a r = 0.659, r = 0.785, and r = 0.862; miR-30d r = 0.742, r = 0.805, r = 0.765; all P < 0.001). Insulin resistance index was an independent factor for expressions of miR124-a and miR-30d. MiR-124a and miR-30d were correlated with insulin resistance and development of BC with T2DM. Although the mechanism is not clear, miR-124a and miR-30d potentially may be used as therapeutic targets and prognostic markers for BC patients with T2DM.
Keywords: Breast cancer; Estradiol; Glycosylated hemoglobin; Insulin resistance index; MiR-124a; MiR-30d; Type 2 diabetes mellitus.