PURPOSE Pregnane x receptor (PXR) - activated overexpression of the multidrug resistance 1 (MDR1) gene is an important way for tumor cells to acquire drug resistance. However, the detailed mechanism still remains unclear. In the present study, we aimed to investigate whether protein arginine methyl transferase 1(PRMT1) is involved in PXR - activated overexpression of MDR1 during acquired multid...

BACKGROUND/AIM Numerous studies have shown that breast cancer and epigenetic mechanisms have a very powerful interactive relation. The MCF7 cell line, representative of luminal subtype and the MDA-MB 231 cell line representative of mesenchymal-like subtype were treated respectively with a Histone Methyl Transferase Inhibitors (HMTi), 3-Deazaneplanocin hydrochloride (DZNep), two histone deacetyl...

The development of drug resistance in cancer cells is one of the major obstacles to achieving effective chemotherapy. We hypothesized that the combination of a doxorubicin (Dox) prodrug and microRNA (miR)21 inhibitor might show synergistic antitumor effects on drug-resistant breast cancer cells. In this study, we aimed to develop new high-density lipoprotein-mimicking nanoparticles (HMNs) for c...

The molecular mechanisms underlying the acquisition of resistance to the antiestrogen Faslodex are poorly understood, although enhanced expression and activity of nuclear factor KB (NFKB) have been implicated as a critical element of this phenotype. The purpose of this study was to elucidate the mechanism by which NFKB up-regulation contributes to Faslodex resistance and to determine whether ph...

The effectiveness of therapies targeting specific pathways in breast cancer, such as the estrogen receptor or HER2, is limited because many tumors manifest resistance, either de novo or acquired, during the course of treatment. To investigate molecular mechanisms of resistance, we used two xenograft models of estrogen receptor–positive (ER+) breast cancer, one with and one without HER2 overexpr...

Tumor cell cycle arrest at the cell cycle G2/M boundary after ionizing radiation involves inhibition of the Polo-like kinase 1 (Plk1). We recently found that the mechanism comprised repression of its gene, PLK, mediated by the tumor-suppressor protein BRCA1. In the present study we examined the regulatory responses on PLK and cell cycle phases in breast carcinoma cell lines exposed to various m...

BACKGROUND Ovarian cancer G protein coupled receptor 1 (OGR1) mediates inhibitory effects on cell migration in human prostate and ovarian cancer cells. However, the mechanisms and signaling pathways that mediate these inhibitory effects are essentially unknown. METHODS MCF7 cell line was chosen as a model system to study the mechanisms by which OGR1 regulates cell migration, since it expresse...

Radiotherapy is one of the main options to cure and control breast cancer. The aim this study was investigate sensitivity two human cancer cell lines, MCF7 MDA-MD-231, radiation exposure at timepoints 4 h 24 after radiation. MDA-MD-231 were irradiated with different doses using a Gilardoni CHF 320 G X-ray generator (Mandello del Lario, Italy) 250 kVp, 15 mA [with half-value layer (HVL) = 1.6 mm...

Survivin is a key member of the inhibitor of apoptosis protein family, and is considered a promising therapeutic target due to its universal overexpression in cancers. Survivin is implicated in cellular radiation response through its role in apoptosis, cell division, and DNA damage response. In the present study, analysis of publically available data sets showed that survivin gene expression in...

Connective tissue growth factor (CTGF) expression is elevated in advanced breast cancer and promotes metastasis. Chemotherapy response is only transient in most metastatic diseases. In the present study, we examined whether CTGF expression could confer drug resistance in human breast cancer. In breast cancer patients who received neoadjuvant chemotherapy, CTGF expression was inversely associate...