Targeting role of CXCL10 and miR-34c-5p in invasive ductal carcinoma of breast / 国际肿瘤学杂志

ABSTRACT

Objective:To explore the targeted relationship between the CXC chemokine ligand 10 (CXCL10) and miR-34c-5p in invasive ductal carcinoma of breast.Methods:A total of 56 cases of invasive ductal carcinoma of breast and 14 cases of benign breast tissues surgically resected and pathologically confirmed in the Third Affiliated Hospital of Sun Yat-sen University were collected from March 2016 to March 2017. The expressions of CXCL10 and miR-34c-5p in the two groups were detected using HTA2.0 and miRNA4.0 chips and verified by reverse transcription quantitative real-time PCR (RT-qPCR). The correlation between the two expressions was analyzed using Pearson correlation analysis and the targeted relationship was predicted by IPA software. The dual luciferase reporter gene system was used to verify the targets of the two and finally verified in breast cancer cell lines MCF-7 and ZR-75-30.Results:The results of gene microarray showed that the mRNA expression values of CXCL10 in invasive ductal carcinoma of breast and benign breast tissues were 7.135±1.350 and 4.348±0.722, and the mRNA expression values of miR-34c-5p in the two groups were 1.309 (1.001, 2.055) and 3.948 (3.278, 4.371), with a statistically significant difference ( t=7.628, P<0.001; Z=-4.405, P<0.001). Pearson correlation analysis showed that the mRNA expressions of CXCL10 and miR-34c-5p were negatively correlated ( r=-0.327, P=0.004). The expression of CXCL10 mRNA was related to the expressions of human epidermal growth factor receptor-2 ( t=2.415, P=0.019) and Ki-67 ( t=2.483, P=0.016), and the expression of miR-34c-5p mRNA was related to the histological grading ( χ2=8.626, P=0.013) and estrogen receptor/progesterone receptor ( Z=-2.195, P=0.028) in patients with invasive ductal carcinoma of breast. RT-qPCR showed that the relative expressions of CXCL10 mRNA in invasive ductal carcinoma of breast and benign breast tissues were 6.059±1.714 and 1.000±0.232, the relative expression levels of miR-34c-5p in the two groups were 0.093±0.004 and 1.000±0.244, with statistically significant differences ( t=3.484, P=0.002; t=5.112, P<0.001), which was consistent with the results of microarray. The results of double luciferase reporter gene showed that, after overexpression of miR-34c-5p, the luciferase activities of WT-CXCL10 and MUT-CXCL10 were 1.117±0.040 and 1.647±0.031 in MCF-7 cells, and the luciferase activities of them were 0.885±0.051 and 1.430±0.020 in HeLa cells, with statistically significant differences ( t=18.120, P<0.001; t=24.040, P<0.001). After transfection with miR-34c-5p and miR-NC respectively, the relative expression levels of CXCL10 were 0.008±0.000 and 0.012±0.000 in ZR-75-30 cells, and the relative expression levels of CXCL10 were 0.315±0.000 and 0.386±0.004 in MCF-7 cells, with statistically significant differences ( t=20.384, P<0.001; t=3.473, P=0.026). Conclusion:The expression of miR-34c-5p in invasive ductal carcinoma of breast is down-regulated, while the expression of CXCL10 is up-regulated. CXCL10 is the target gene of miR-34c-5p.