The human ATP-binding cassette superfamily G (White) member 2 (ABCG2) gene and its murine homologue breast cancer resistance protein 1 (Bcrp1) are recently described ATP-binding cassette transporters associated with drug resistance in tumor cell lines, including the MCF-7 cell line, selected for its resistance to mitoxantrone (MCF-7/MitoR). Infection of MCF-7 cells with the retroviral vector co...

Marine microalgae have been prominently featured in cancer research. Here, we examined cytotoxic effect and apoptosis mechanism of crude ethanol extracts of an indigenous microalga, Chaetoceros calcitrans (UPMAAHU10) on human breast cell lines. MCF-7 was more sensitive than MCF-10A with IC50 value of 3.00 ± 0.65, whilst the IC50 value of Tamoxifen against MCF-7 was 12.00 ± 0.52  μg/mL after 24 ...

Choline kinase-α (Chk-α) and autophagy have gained much attention, as they relate to the drug-resistance of breast cancer. Here, we explored the potential connection between Chk-α and autophagy in the mechanisms driving to tamoxifen (TAM) resistance, in estrogen receptor positive (ER+) breast cancer cells (BCCs). Human BCC lines (MCF-7 and TAM-resistant MCF-7 (MCF-7/TAM) cells) were used. Chk-α...

The current view of multidrug resisitance is that overexpression of membrane P-glycoprotein (P-gp) is a major causative factor. However, the controversial presence of subcellular P-gp may also participate in the drug resistance. In this study, we sought to investigate the localization and functional characterization of P-gp in mitochondria isolate...

We previously showed that S-adenosylmethionine-mediated hypermethylation of the PTEN promoter was important for the growth of tamoxifen-resistant MCF-7 (TAMR-MCF-7) cancer cells. Here, we found that the basal expression level of methionine adenosyltransferase 2A (MAT2A), a critical enzyme for the biosynthesis of S-adenosylmethionine, was up-regulated in TAMR-MCF-7 cells compared with control MC...

OBJECTIVE To explore the biological effects of ray cartilage extract (RCE) on human breast cancer cell line MCF-7 and its mechanism. METHODS MCF-7 cells were treated with RCE of different concentrations for different durations, and then MCF-7 cell proliferation was evaluated with MTT test, cell cycle was detected with flow cytometer and the protein levels of cyclin D1 and p21 were determined ...

OBJECTIVE Tamoxifen is currently used for the treatment of estrogen receptor-positive breast cancer patients, but acquired resistance to tamoxifen is a critical problem in breast cancer therapy. Suberoylanilide hydroxamic acid (SAHA) is a prototype of the newly developed HDAC inhibitor. The aim of this study is to investigate the anticancer effects of SAHA in tamoxifen-resistant MCF-7 (TAMR/MCF...

BACKGROUND Multidrug resistance (MDR) directly contributes to the clinical failure of chemotherapy in breast cancer (BCA). β-elemene is a natural antitumor drug from plants. We previously confirmed that MDR could be reversed by β-elemene. In this study, we intended to investigate the reversal effect of β-elemene on MDR in human BCA adriacin (Adr) -resistant MCF-7 cells (MCF-7/Adr) and docetaxel...

MicroRNAs (miRNAs) represent a class of small non-coding RNAs regulating gene expression by inducing RNA degradation or interfering with translation. Aberrant miRNA expression has been described for several human malignancies. Herein, we show that miR-145 is down-regulated in human cancer cell line MCF-7 when compared to normal human mammary epithelial cell line MCF10A. Overexpression of miR-14...