ABSTRACT
Objective:To detect the expression level of tRF-31-PER8YP9LON4VD in the serum of breast cancer patients and to explore its effect on the function of breast cancer cells.Methods:The serums of 57 breast cancer patients, 39 breast benign tumor patients and 40 normal physical examination patients in the Affiliated Cancer Hospital of Nanjing Medical University from April to August in 2022 were collected. Real-time quantitative polymerase chain reaction(RT-qPCR) to detect the expression level of tRF-31-PER8YP9LON4VD in breast cancer cell lines and serum of breast cancer patients. Cell invasion assay, migration assay and CCK-8 proliferation assay were used to analyze the effect of tRF-31-PER8YP9LON4VD on breast cancer cell function. The receiver operating characteristic curve (ROC) curve was used to analyze the diagnostic efficacy of tRF-31-PER8YP9LON4VD in serum in breast cancer. The chi-square test was used to analyze the correlation between tRF-31-PER8YP9LON4VD and clinical features.Results:The expression levels of tRF-31-PER8YP9LON4VD in breast cancer cell lines MDA-MB-231 (0.50±0.22 vs 1.00±0.01), T-47D (0.33±0.02 vs 1.00±0.01) and MCF-7 (0.50±0.02 vs 1.00±0.01) were significantly lower than those in normal mammary epithelial cell lines (1.00±0.01), and the difference was statistically significant (all P<0.05). The expression level of tRF-31-PER8YP9LON4VD in the serum of breast cancer patients (1.35±1.25) was lower than that in the serum of patients with normal physical examination (6.42±3.13) and patients with benign breast tumors (9.57±2.11), and the difference was statistically significant (both P<0.001). Compared with the control group, the invasiveness of overexpressing tRF-31-PER8YP9LON4VD T-47D (86.67±12.22 vs 532.00±22.68, P<0.001) and MDA-MB-231 (535.33±99.12 vs 1 055.67±24.00, P=0.002) was weaker, and that of T-47D (442.67±81.79 vs 1 210.67±115.02, P=0.002) and MDA-MB-231 (278.67±108.40 vs 571.33±95.37, P=0.015) had weaker migration ability, and T-47D and MDA-MB-231 had weaker proliferative ability (all P<0.05). The area under the curve of serum tRF-31-PER8YP9LON4VD for the diagnostic efficacy of breast cancer was 0.743 (95% CI 0.644-0.842), and the sensitivity and specificity were 89.50% and 53.10%, respectively. Conclusion:tRF-31-PER8YP9LON4VD is low expressed in the serum of breast cancer patients, and it may inhibit the proliferation, migration and invasion of breast cancer cells.
ABSTRACT
Objective:To investigate the level of the transporter RNA (tRNA) derivative tRF-5026a in the serum of breast cancer patients and its value for the diagnosis of breast cancer, and to investigate its effect on the biological functions of breast cancer cells in vitro and the possible mechanisms.Methods:Sixty female breast cancer patients (breast cancer group) hospitalized in Jiangsu Cancer Hospital from January 2016 to February 2019 and 20 healthy women undergoing physical examination during the same period (healthy control group) were retrospectively selected. The relative expression of serum tRF-5026a in the study subjects was detected by real-time quantitative polymerase chain reaction (RT-qPCR). The receiver operating characteristic (ROC) curve of serum tRF-5026a level for the diagnosis of breast cancer was drawn with pathological diagnosis as the gold standard. tRF-5026a mimics (tRF-5026a group) and negative control sequences (negative control group) were transiently transfected into MCF-7 and BT549 cells by lipofectamine method; CCK-8 assay and 5-ethynyl-2-deoxyuridine (EdU) assay were used to detect the ability of cell proliferation in cells of each group; cell apoptosis in cells of each group was detected by flow cytometry; the abilities of cell invasion and migration in cells of each group were detected by Transwell assay; the expressions of epithelial mesenchymal transition-related proteins in cells of each group were detected by Western blotting.Results:The relative expressions of tRF-5026a [ M ( Q1, Q3)] in serum of healthy control group and breast cancer group were 16.58 (6.37, 26.31) and 3.46 (0.32, 9.01), with a statistically significant difference ( Z = -4.27, P < 0.001). ROC curve analysis showed that the area under the curve (AUC) for diagnosis of breast cancer by the relative expression of serum tRF-5026a was 0.820 (95% CI: 0.722-0.918), with an optimal cut-off value of 9.082, and the corresponding sensitivity and specificity were 75.0 % and 76.7%, respectively. The apoptosis rates of MCF-7 cells in the tRF-5026a group and the corresponding negative control group were (16.52±0.51)% and (12.28±1.75)%, and the BT549 cells were (13.27±2.18)% and (8.86±0.29)%, the differences were not statistically significant (both P > 0.05). MCF-7 and BT549 cells in the tRF-5026a group had lower proliferative, invasive and migratory abilities than cells in the corresponding negative control group (all P < 0.05). MCF-7 and BT549 cells in the tRF-5026a group had lower protein expressions of N-cadherin, matrix metalloproteinase (MMP)-9 and MMP-3 than cells in the corresponding negative control group. Conclusions:tRF-5026a has low level in the serum of breast cancer patients and it may be an indicator for breast cancer diagnosis. tRF-5026a can inhibit the proliferation, invasion and migration of breast cancer MCF-7 and BT549 cells in vitro, which may be related to the regulation of epithelial mesenchymal transition.