Personalized Breast Cancer Screening Using Circulating MicroRNAs as Potential Biomarker in Whole Blood

Personalized medicine is defined as studying a person’s genes, proteins and environment to increase the efficiency of diagnosis and treatment. The first step in personalized medicine is diagnostic testing to separate patients into different groups. MicroRNAs are a new class of small non-coding RNAs that have a regulatory role at the post-transcriptional level of gene expression. Aberrant expression of miRNAs is related to many diseases such as cancer so it can be used as a biomarker for diagnosis and prognosis. Circulating microRNAs are stable in body fluids such as blood, serum, plasma etc. We investigated to find the best group of candidate microRNAs and design a panel for early detection of breast cancer.We analyzed miRNome data from the cancer genome atlas (TCGA) with a computational approach. In the first step, we analyzed 6104 samples from 14 different types of cancers and normal tissues, and then Differential Expression between 778 Breast cancer samples, 87 control samples and all other cancer and normal samples were done. We also performed Differential Expression between candidate list with 105 circulating miRNA microarray data sets from invasive ductal carcinoma samples to validate the candidates.We found that miRNAs can distinguish normal samples from tumors so they can be regarded as good biomarkers. The candidate list with a threshold of adjusted P values less than 0.001 and absolute log fold changes more than one were selected. A list of 54 differentially expressed miRNAs can separate Breast Cancer from all normal tissues with a good P value. As 16 of the 54 candidates are significantly deregulated in all cancers, we focused on the other 38 by considering their different features and then compared this list with circulating miRNA data sets to achieve the final candidate list comprising 17 miRNAs for the early detection of breast cancer.Although miRNA profiling using whole blood is a potential biomarker for early detection of breast cancer, clinical validation of these new candidate biomarkers in the wet lab is necessary.

کلیدواژه ها:

Personalized medicine ، Circulating MicroRNA ، Biomarker ، Breast cancer ، Early detection ، Bioinformatics