Triple Negative Breast Cancer Profile, from Gene to microRNA, in Relation to Ethnicity

Abstract

Breast cancer is the most frequent cause of cancer-related deaths among women worldwide. It is classified into four major molecular subtypes. Triple-negative breast cancers (TNBCs), a subgroup of breast cancer, are defined by the absence of estrogen and progesterone receptors and the lack of HER-2 expression; this subgroup accounts for ~15% of all breast cancers and exhibits the most aggressive metastatic behavior. Currently, very limited targeted therapies exist for the treatment of patients with TNBCs. On the other hand, it is important to highlight that knowledge of the molecular biology of breast cancer has recently changed the decision-making process regarding the course of cancer therapies. Thus, a number of new techniques, such as gene profiling and sequencing, proteomics, and microRNA analysis have been used to explore human breast carcinogenesis and metastasis including TNBC, which consequently could lead to new therapies. Nevertheless, based on evidence thus far, genomics profiles (gene and miRNA) can differ from one geographic location to another as well as in different ethnic groups. This review provides a comprehensive and updated information on the genomics profile alterations associated with TNBC pathogenesis associated with different ethnic backgrounds.

Keywords: biomarkers; breast cancer; gene expression profiling; miRNA; microarray; triple negative breast cancer.

Figure 1

Schematic outline showing normal and abnormal genes and miRNA profiles of normal mammary and breast cancer. It is evident that there are variations in gene expressions and miRNA profiles from normal to non-invasive and invasive cancer, in which epithelial-mesenchymal transition (EMT) is the main hallmark. Thus, combined gene and miRNA profiles can be used as novel Biomarkers and therapy targets for each step of cancer progression. However, it is important to highlight that Gene and miRNA profiles can differ from one geographic location to another as well as between different ethnic groups.