<p>Mirna21 Expression in the Breast Cancer Tumor Tissue is Independent of Neoadjuvant Chemotherapy</p>

Abstract

Introduction: MicroRNA-21 (miRNA-21) has been described as one of the most significantly upregulated miRNAs in human breast cancer. However, limited knowledge exists on miRNA-21 expression in breast cancer tissue after neoadjuvant chemotherapy (NAC). Purpose: The aim of this study was to assess miRNA-21 expression in the tumor tissues of Brazilian patients with breast cancer who underwent NAC and its correlation with clinicopathological variables. Patients and Methods: Utilizing qRT-PCR, miRNA-21 expression in tumor tissue was measured in a cohort of female patients with breast cancer who underwent NAC. The correlation of miRNA-21 expression with breast cancer molecular subtypes and other clinicopathological variables was also assessed. Results: A total of 55 patients were included in the study, and 28 (50.9%) underwent NAC. miRNA-21 was upregulated in patients with breast cancer, regardless of previous exposure to chemotherapy, molecular subtypes, tumor-node-metastasis (TNM) staging and lymph node status of the axilla. miRNA-21 expression did not differ between patients with breast cancer who achieved a pathologic complete response after NAC and healthy controls. Conclusion: miRNA-21 was upregulated in the tumor tissue of Brazilian patients with breast cancer regardless of NAC treatment, which reinforces its role as an "oncomiR" and a potential biomarker.

A study comparing the oncogenic microRNA-21-5p and the CA15-3 characteristics as an effective tumor marker in breast cancer patients from Iraq.

“…Circulating MiRNAs are emerging as new diagnostic and prognostic biomarkers for BC; there help predict tumor response to specific chemotherapeutic drugs 8 . MicroRNA-21 has been described as one of the most significantly up-regulated miRNAs in human breast cancer regardless of pre-vious exposure to chemotherapy treatment which reinforces its role as an "oncomiR" and a potential biomarker 9 . The study aims to analyze the expression quantity of serum (miR-21-5p) and compare it with one of the most widely used serum markers (CA15-3), then check sensitivity, specificity, accuracy, quality and discrimination power comparison for both miRNA-21 and CA15-3 markers.…”

Intraabdominal sporadic desmoid tumors and inflammation: an updated literature review and presentation and insights on pathogenesis of synchronous sporadic mesenteric desmoid tumors occurring after surgery for necrotizing pancreatitis

“…Related to multiple cancers [ 50 , 51 ], miR-21 targets and inhibits the tumor-related genes of programmed cell death 4 (PDCD4), and phosphatase and tensin homolog (PTEN) [ 52 ]; it is involved in tumor angiogenesis, which is closely related to tumor cell proliferation, invasion, and drug resistance [ 53 , 54 ]. We found that miR-21 was upregulated in the four synchronous desmoids showing significant nuclear positivity for β-catenin, in line with experimental evidence that overexpressed miR-21-5p associated with mutated CTNNB1 promoted increased phosphorylation of β-catenin and nuclear translocation in colorectal cancer cell lines [ 55 ].…”

Advanced breast cancer diagnosis: Multiplex RT-qPCR for precise typing and angiogenesis profiling

“…ΔΔCT values were derived from treated samples compared to control samples, determining fold changes using the formula 2^(-ΔΔCT). This technique enabled rapid and precise evaluation of gene expression alterations in response to experimental conditions[ 31 , 32 ].…”