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.
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.
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).
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).
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.
(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.
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.