Our data suggest circulating miR-21 (both in serum and in PBMCs) can serve as a good biomarker for GC and could be used in diagnosis of early (stage I) and late GC (stage IV).
Differential expression of miR-21, miR-320c, and miR-1225-5p was validated in the PLF of serosa-invasive and non-invasive GC by qRT-PCR and miR-21 and miR-1225-5p were confirmed to be associated with serosal invasion in GC.
Overexpression of miR-21 decreased the sensitivity of GC cells to trastuzumab, while suppression of miR-21 expression restored the resistance of GC cells to trastuzumab.
The results suggested plasma miR-21 could be a novel potential biomarker for GC prognosis and evaluation of surgery outcomes, especially in patients without a family history.
Literature database including PubMed, Embase, the Cochrane Library, Web of Science, Ovid, SciVerse, Science Direct, Scopus, BioMed Central, Biosis previews,Chinese Biomedical Literature Database (CBM), Chinese National Knowledge Infrastructure (CNKI), Technology of Chongqing (VIP), and Wan Fang DATA were searched for publications concerning the diagnostic value of miR-21 for GC without language restriction.
These results suggest that miR-21 may provide a novel mechanism for understanding cisplatin resistance in gastric cancer by modulating PTEN/PI3K/Akt pathway.
Real-time PCR analysis indicated that miR-21 exhibited higher expression in gastric cancer tissues compared to the adjacent non-tumor tissues. miR-21 expression was significantly associated with the degree of differentiation of the tumour tissues (P=0.004), as well as local invasion and lymph node metastasis (P<0.01).
The objectives of this study were: i) to establish the clinicopathological and prognostic significance of PDCD4 mRNA, and ii) to elucidate any correlation between PDCD4 mRNA and miR-21 in gastric cancer.
Remarkably, miR-21 was also significantly overexpressed in H. pylori-infected gastric mucosa, implying that overexpression of miR-21 in gastric cancer may be due in part to H. pylori infection.