ABSTRACT
Aim To investigate the role and potential mechanism of methyltransferase-like 5 (METTL5) in triple-negative breast cancer (TNBC) . Methods The expression of METTL5 in TNBC tumor tissues and cell lines was detected by immunohistochemistry and Western blot. After shRNA targeting METTL5 (shRNAMETTL5) was transfected into TNBC cells, cell proliferation, migration and invasion were detected by CCK-8, colony formation, wound healing and Transwell assays, respectively. Western blot was used to detect the expression of Wnt/p-catenin signaling-related key proteins. A xenograft tumor model was constructed to verify the effect of METTL5 knockdown on the growth of TNBC cells and Wnt/p-catenin signaling activity in vivo. Results The expression of METTL5 was up-regulated in TNBC tumor tissues and cell lines (P < 0. 01) . Knockdown of METTL5 significantly inhibited the proliferation, migration and invasion of TNBC cells and reduced the expression of Wnt/p-catenin signaling molecules (3-catenin, cyclin Dl, matrix metalloproteinase (MMP) -2 and MMP-7 (all P < 0. 01) . Knockdown of METTL5 reduced tumor growth and Wnt/pcatenin signaling activity in vivo. Conclusions Knockdown of METTL5 can inhibit the proliferation, migration and invasion of TNBC cells, which may be related to the inhibition of Wnt/p-catenin signaling pathway.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the correlation of microRNA-155 (miR-155) expression with clinicopathological features of patients with papillary thyroid carcinoma (PTC) and explore the value of miR-155 in prognostic assessment of PTC.</p><p><b>METHODS</b>We collected 86 pairs of fresh PTC and adjacent tissues to examine the expression of miR-155 using fluorescent quantitative PCR. miR-155 expressions in the tissues were analyzed in relation to the clinicopathological features of the patients.</p><p><b>RESULTS</b>Compared with the paired adjacent tissues, 69.8% (60/86) of the PTC tissues showed up-regulated miR-155 expression by 2.63∓2.73 folds. Up-regulated miR-155 expressions were associated with a larger tumor size (1.66∓0.96 vs 1.19∓0.52 cm, P=0.021), a higher likeliness of extrathyroid invasion (56.7% vs 23.1%, P=0.004), a higher rate of lymph node metastasis (70% vs 46.2%, P=0.036), a more advanced TNM stage, and a higher rate of III-IV stage of the tumor (20% vs 0%, P=0.014). The expression level of miR-155 in PTC tissues was positively correlated with lymph node metastasis (r=0.531, P=0.001).</p><p><b>CONCLUSION</b>PTC patients with miR-155 over-expression tend to have a greater tumor size, a greater likeliness of extrathyroid involvement, a higher rate of cervical lymph node metastasis and a more advanced TNM stage. The high expression of miR-155 in the tumor may indicate a poor prognosis of PTC patients.</p>