New Insights in Gene Expression Alteration as Effect of Paclitaxel Drug Resistance in Triple Negative Breast Cancer Cells.

BACKGROUND/AIMS: Triple negative breast cancer (TNBC) is a highly aggressive form of cancer which lacks targeted therapy options. Thus, TNBC patients have poor outcomes and a decreased survival rate than patients with other types of breast cancers. Due to the lack of surface receptors, TNBC needs a comprehensive investigation to provide more information regarding patient's therapy, as well as to understand the way how to counteract drug resistance mechanisms. Nowadays, chemotherapy remains an unsolved issue which rise a lot of questions in oncology field. METHODS: In this article, we investigated the implication of paclitaxel in TNBC cell lines after a prolong administration, after 12, respectively 24 passages followed by evaluation of morphological alteration, mutational pattern by next generation sequencing and the altered gene expression pattern by microarray technology and validation by qRT-PCR of the resistance to therapy relevant genes. RESULTS: Using functional assays, we showed that paclitaxel exhibits antiproliferative activity on Hs578T/Pax and MDA-MB-231/Pax demonstrating the activation of cell death mechanisms. Confocal microscopy revealed significant modifications which occur in the morphological structure with a disruption of the actin-filaments and also mitotic catastrophe. The presence of these nuclear alterations is due to some modifications at the cellular and molecular levels. Important alterations at the transcriptomic and genomic levels were observed from this a common drug resistance signature (IL-6, CXCL8, VEGFA, EGR1, PTGS2 and TRIB1) for both cell lines at 24 passages was discovered. Also, an important mutation (TP53) linked with drug response was identified. CONCLUSION: These results might be used to furnish novel biomarkers in TNBC, as well as to find a strategy to counteract the resistance to therapy in order to increase survival rate and to enhance the prognosis of patients with TNBC.

The Relevance of Mass Spectrometry Analysis for Personalized Medicine through Its Successful Application in Cancer "Omics".

Mass spectrometry (MS) is an essential analytical technology on which the emerging omics domains; such as genomics; transcriptomics; proteomics and metabolomics; are based. This quantifiable technique allows for the identification of thousands of proteins from cell culture; bodily fluids or tissue using either global or targeted strategies; or detection of biologically active metabolites in ultra amounts. The routine performance of MS technology in the oncological field provides a better understanding of human diseases in terms of pathophysiology; prevention; diagnosis and treatment; as well as development of new biomarkers; drugs targets and therapies. In this review; we argue that the recent; successful advances in MS technologies towards cancer omics studies provides a strong rationale for its implementation in biomedicine as a whole.

Epithelial-Mesenchymal Transition Gene Signature Related to Prognostic in Colon Adenocarcinoma.

Colon adenocarcinoma (COAD) remains an important cause of cancer-related mortality worldwide. Epithelial-mesenchymal transition (EMT) is a key mechanism, promoting not only the invasive or metastatic phenotype but also resistance to therapy. Using bioinformatics approaches, we studied the alteration on EMT related genes and its implication on COAD prognostic based on public datasets. For the EMT mechanisms, two overexpressed genes were identified (NOX4 and IGF2BP3), as well as five downregulated genes (BMP5, DACT3, EEF1A2, GCNT2 and SFRP1) that were related to prognosis in COAD. A qRT-PCR validation step was conducted in a COAD patient cohort comprising of 29 tumor tissues and 29 normal adjacent tissues, endorsing the expression level for BMP5, as well as for two of the miRNAs targeting key EMT related genes, revealing upregulation of miR-27a-5p and miR-146a-5p. The EMT signature can be used to develop a panel of biomarkers for recurrence prediction in COAD patients, which may contribute to the improvement of risk stratification for the patients.

New insights in gene expression alteration as effect of doxorubicin drug resistance in triple negative breast cancer cells.

BACKGROUND: Triple negative breast cancer (TNBC) is a heterogeneous disease with aggressive behavior and an unfavorable prognosis rate. Due to the lack of surface receptors, TNBC must be intensely investigated in order to establish a suitable treatment for patients with this pathology. Chemoresistance is an important reason for therapeutic failure in TNBC. METHOD: The aim of this study was to investigate the effect of doxorubicin in TNBC cell lines and to highlight cellular and molecular alterations after a long exposure to doxorubicin. RESULTS: The results revealed that doxorubicin significantly increased the half maximal inhibitory concentration (IC50) values at P12 and P24 compared to parenteral cells P0. Modifications in gene expression were investigated through microarray technique, and for detection of mutational pattern was used Next Generation Sequencing (NGS). 196 upregulated and 115 downregulated genes were observed as effect of multiple dose exposure, and 15 overexpressed genes were found to be involved in drug resistance. Also, the presence of some additional mutations in both cell lines was observed. CONCLUSION: The outcomes of this research may provide novel biomarkers for drug resistance in TNBC. Also, this activity can highlight the potential mechanisms associated with drug resistance, as well as the potential therapies to counteract these mechanisms.