Quantitative Measurement of Serum MicroRNA-21 Expression in Relation to Breast Cancer Metastasis in Chinese Females

BACKGROUND: Breast cancer is the most common type of cancer in females. Aberrant expression of microRNA-21 (miR-21) has previously been reported in breast cancer tissue. The aim of this study was to investigate expression levels of serum miR-21 in breast cancer patients and evaluate its prognostic value in Chinese females. METHODS: Real-time quantitative (RQ)-PCR was used to analyze miR-21 expression in archived serum, tumor tissue, and adjacent normal tissue from 549 participants (326 with breast cancer, 223 without breast cancer). We also analyzed associations between serum miR-21 expression and breast cancer subtypes and patient prognosis. Recurrence and survival were analyzed by using the multivariate Cox proportional hazards model. RESULTS: Expression of miR-21 was significantly higher in breast cancer tissues compared with normal adjacent breast tissues (P<0.001). The 2(-DeltaDeltaCt) values for serum miR-21 in breast cancer patients versus healthy controls were 9.12+/-3.43 and 2.96+/-0.73, respectively. Multivariate Cox proportional hazards model suggested that serum miR-21 expression was an independent poor prognostic factor for both recurrence (hazard ratio [HR]= 2.942; 95% confidence interval [CI]=1.420-8.325; P=0.008) and disease-free survival (HR=2.732; 95% CI=1.038-7.273, P=0.003) in breast cancer. CONCLUSIONS: Increased serum miR-21 expression level was correlated with poor prognosis of breast cancer patients, indicating that serum miR-21 may be a novel prognostic marker for recurrence and survival of breast cancer patients before resection.

Metallothionein lower under-expression in benign tumors than that in malignant tumors: systematic review article and meta-analysis

Metallothionein [MT] manifests varying expression levels in carcinomas, and they may be considered as valuable cell cancerization biomarkers for diagnosis of patients with cancers. A meta-analysis was conducted to evaluate comprehensively the MT expression difference in various benign tumors and malignant tumors, which compared the high with low MT expression levels in patients of the available studies. Finally, a total of 13 studies dealing with various tumors were involved for this meta-analysis. The results indicated that lower expression of MT in various benign tumors tissue than that in corresponding malignant tumors with the pooled OR of 0.52 [95 % CI 0.18-1.47, P <0.001]. In conclusion, MT expression difference is associated with tumor various stages in tumor patients and could be a useful clinical criteria of distinguishing benign tumors and malignant tumors for those patients