[Expression and regulatory mechanism of S100A14 in breast cancer]

To explore the expression of S100A14 in breast cancer tissue, and the EGF and S100A14 feedback regulatory mechanism.

S100A14 mRNA level in 52 cases of of breast cancer and adjacent normal tissue was detected by quantitative real-time PCR. S100A14 protein in 21 cases of breast cancer and adjacent normal tissue was detected by Western blot. S100A14 mRNA after EGF treatment was detected by RT-PCR and real-time PCR. The levels of S100A14, p-ERK and t-ERK were detected by Western blot. Knocking down S100A14 expression was performed by siRNA technology.

The levels of S100A14 mRNA and protein were significantly increased in breast cancer tissues (P<0.05 for both). The high expression of S100A14 was related with the recurrence of breast cancer patients (P= 0.038). S100A14 mRNA level was significantly up-regulated in the MDA-MB-453 cells (1.50±0.11) and MCF-7 cells (1.40±0.03) after 1 ng/mL EGF treatment, and 1.66±0.08 and 1.71±0.17 in the MDA-MB-453 cells after 10 ng/mL EGF treatment, significantly higher than that of the control group (1.00±0.09 and 1.00±0.03) (P<0.05 for both). In the TD47 cells, the S100A14 mRNA levels in the control, 1 ng/ml EGF and 10 ng/ml EGF + U0126 treatment groups were 1.00±0.04, 1.56±0.04 and 1.00±0.10, respectively (P<0.05).

The expression of S100A14 mRNA and protein is promoted by EGF through p-ERK signaling pathway in breast cancer cells. There may be a feedback loop between EGF and S100A14.