(1) In preliminary tests, the plasma level of miR-21 was significantly higher (P=0.0218) and that of miR-375 (P=0.0052) was significantly lower in ESCC patients than controls.
The results of the present study revealed that miR-375 was downregulated in ESCC tumor tissue and EC109 cells compared with normal tissue and Het-1A cells (P<0.01).
This meta-analysis demonstrated that the downexpression of miR-375 was significantly correlated with poor OS in patients with SCCs and indicated the potential clinical use of miR-375 as a molecular biomarker, particularly in assessing prognosis for patients with ESCC and HNSCC.
The expression of miR-375 was downregulated in ESCC tissues, and ectopic expression of this miRNA markedly inhibited cancer cell migration and invasion, suggesting that miR-375 acted as an antimetastatic miRNA in ESCC cells.
Among the 5 miRNAs considered (miR-21, miR-223, miR-375, miR-25 and miR-100), miR-21 and miR-223 were significantly overexpressed whereas miR-375 expression was reduced in patients with ESCC compared with healthy individuals (all P<0.001).
Our microRNA (miRNA) expression signatures of hypopharyngeal squamous cell carcinoma, maxillary sinus squamous cell carcinoma and esophageal squamous cell carcinoma revealed that miR-375 was significantly reduced in cancer tissues compared with normal epithelium.
miR-503 was highly expressed in esophageal squamous cell carcinoma and miR-375 was lowly expressed in esophageal squamous cell carcinoma. miR-503 and miR-375 were closely related to the lymphatic metastasis, degree of differentiation and TNM staging of the tumor.