BackgroundInflammatory breast cancer (IBC) is an extremely malignant form of breast cancer which can be easily misdiagnosed. Conclusive prognostic IBC molecular biomarkers which are also providing the perspectives for targeted therapy are lacking so far. The aim of this study was to reveal the IBC-specific miRNA expression profile and to evaluate its association with clinicopathological parameters.MethodsmiRNA expression profiles of 13 IBC and 17 non-IBC patients were characterized using comprehensive Affymetrix GeneChip miRNA 3.0 microarray platform. Bioinformatic analysis was used to reveal IBC-specific miRNAs, deregulated pathways and potential miRNA targets.Results31 differentially expressed miRNAs characterize IBC and mRNAs regulated by them and their associated pathways can functionally be attributed to IBC progression. In addition, a minimal predictive set of 4 miRNAs characteristic for the IBC phenotype and associated with the TP53 mutational status in breast cancer patients was identified.ConclusionsWe have characterized the complete miRNome of inflammatory breast cancer and found differentially expressed miRNAs which reliably classify the patients to IBC and non-IBC groups. We found that the mRNAs and pathways likely regulated by these miRNAs are highly relevant to cancer progression. Furthermore a minimal IBC-related predictive set of 4 miRNAs associated with the TP53 mutational status and survival for breast cancer patients was identified.Electronic supplementary materialThe online version of this article (doi:10.1186/1756-0500-7-871) contains supplementary material, which is available to authorized users.

Hyperexpression of HER-2/neu is found in tissues of 25-30% patients with primary breast cancer. Monotherapy with antitumor drug trastuzumab as second-third line therapy and its combination with cytostatics prolong the interval before disease progress and the overall survival of patients with metastatic HER-2/neu+ tumors. Trastuzumab is now prescribed after evaluation of HER-2/neu status by the immunohistochemical method and/or fluorescent in situ hybridization. We have developed a method for evaluating the HER-2/neu status of breast cancer biopsy specimens by real time reverse transcription PCR. Based on the analysis of published data, six candidate genes in the pericentromer region of chromosome 17 are selected for data normalization. Stability of these genes is verified on the cell model (MCF-7 and SK-BR-3) and on biopsy materials. The sensitivity and specificity of the method is evaluated on a collection of biopsy specimens.

Inflammatory breast cancer is characterized by high malignancy, early and rapid lymphogenic and hematogenic metastasizing, and high mortality. The diagnosis of this form of cancer is based fully on the clinical criteria. Whole transcriptome analysis of tumor tissue specimens from patients with inflammatory breast cancer detected 137 differentially expressed mRNA (17 genes with low expression and 120 with high expression). Genes involved in the organization of inflammatory process, chemotaxis, and transcription regulation were active in the process of pathogenesis of inflammatory breast cancer.

The paper presents a formalized statement of the problem of selecting parameters and construction of a genomic classifier for medical test systems with mathematical methods of machine learning without the use of biological and medical knowledge. A method is proposed to solve this problem. The results of testing the method using microarray datasets containing information on genome-wide transcriptome of the samples of estrogen positive breast tumors are discussed. Testing showed that the quality of classification provided by the constructed test system and implemented on the basis of assessments of expression of 12 genes is not inferior to the quality of classification carried out by such test systems as OncotypeDX and MammaPrint.