MicroRNAs and Metastasis-related Gene Expression in Egyptian Breast Cancer Patients

Pilot Study of Serum MicroRNA-21 as a Diagnostic and Prognostic Biomarker in Egyptian Breast Cancer Patients

“…Meanwhile, no significant association was found between expression of miR-21 and tumor location, histological type, or size. Our results were in agreement with other prior studies which reported that miR-21 over-expression was associated with tumor grades, higher proliferation index, and lymph node metastasis in BC [5,13,30,76]. Other previous studies showed that miR-21 levels are positively correlated with vascular invasion, visceral metastasis, and advanced clinical stage [13,46,77], and associated with poor response to therapy, and worse survival in BC [49,[78][79][80][81].…”

“…M metastasis, N lymph node status, RNU6B small nuclear RNA U6, T tumor size with those without metastasis (stages II/III; 2.78-fold). This result was in agreement with a study conducted by Hafez et al, who reported a 10.69-fold increase in miR-21 expression compared with normal adjacent tissues among Egyptian women [30]. Similar over-expression levels were reported in the circulation of BC patients with different ethnic backgrounds [5,13].…”

Differential Distribution of miR-20a and miR-20b may Underly Metastatic Heterogeneity of Breast Cancers

“…In the past decade there have been remarkable advances in our understanding of microRNAs and their function in a large range of developmental and physiological processes (Hafez et al, 2012;Letonqueze et al, 2012). These small endogenous non-coding RNAs regulate hundreds of posttranscriptionally expressed genes, and recently, have been shown to play an important role in various human cancers (Nana-Sinkam and Croce, 2011;Piao and Ma, 2012).…”

The novel role of miRNAs for tamoxifen resistance in human breast cancer

“…TIMP3, a tissue inhibitor of metalloproteinases in the extracellular matrix, shows a selective ability to inhibit several ADAMs (a disintegrin and metalloproteases) as well as matrix metalloproteinases [46]. Previous studies have shown that suppression of TIMP3 expression by miR-21 in breast cancer tissues and cell lines contributes to promote invasion and metastasis in breast cancer cells [47,48]. Recent clinical data suggest high TIMP3 expression was associated with a prolonged metastasis-free survival (MFS), but there was no significant association with overall survival (OS) in breast cancer patients [49].…”