The estrogen-induced 52K protein secreted by human breast cancer cells is a lysosomal protease recently identified as a pro-cathepsin D by sequencing several cDNA clones isolated from MCF7 cells (Augereau et al., Mol. Endocr.). Using one of these clones, we detected, in MCF7 cells, a 2.2 kb mRNA whose level was rapidly increased 4- to 10-fold by estradiol, but not by other classes of steroids. ...

The present study aimed to identify the differentially expressed genes (DEGs) regulated by microRNA (miRNA)-221 and miRNA-222 that are associated with the resistance of breast cancer to fulvestrant. The GSE19777 transcription profile was downloaded from the Gene Expression Omnibus database, and includes data from three samples of antisense miRNA-221-transfected fulvestrant-resistant MCF7-FR bre...

Lauryl gallate is an antioxidant food additive showing low toxicity to normal cells. Here, its antiproliferative effect has been studied on three human breast cancer cell lines: estrogen-dependent, wild-type p53, MCF7; estrogen-independent, non-functional p53, MDA-MB-231 and MCF7 ADR, which overexpresses P-glycoprotein (P-gp) and displays a multidrug-resistant phenotype. Lauryl gallate inhibite...

MicroRNAs (miRs) are small RNAs that do not code for proteins, but instead decrease the stability and suppress the translation of target mRNAs by binding with complementary sequences in their 3'-untranslated regions (3'-UTRs). In the present study, it is reported that breast cancer tumor tissue, as well as irradiated MCF7 breast cancer cells, exhibit decreased levels of miR-26b expression compa...

Estrogen receptor (ER) α-positive breast cancers initially respond to antiestrogens but eventually become estrogen independent and recur. ER(+) breast cancer cells resistant to long-term estrogen deprivation (LTED) exhibit hormone-independent ER transcriptional activity and growth. A kinome-wide siRNA screen using a library targeting 720 kinases identified Polo-like kinase 1 (PLK1) as one of th...

Mentha pulegium L. is one of the Mentha (Labiatae) species that is grown in many different parts of the earth including northern Iran. The total ethanolic extract of the aerial parts of this plant is used in this work to investigate on the possible cytotoxicity on two different cell lines. Human lung carcinoma cells (A549) and human breast cancer (MCF7), have been used to show the clonogenic co...

Tamoxifen is the first line drug used in the treatment of estrogen receptor-positive (ER+) breast cancer. The development of multidrug resistance (MDR) to tamoxifen remains a major challenge in the treatment of cancer. One of the mechanisms related to MDR is decrease of drug influx via overexpression of drug efflux transporters such as P-glycoprotein (P-gp/MDR1), multidrug resistance associated...

A hormone-independent but hormone-responsive subpopulation (MCF7/ Mil l ) of the hormone-dependent MCF-7 human breast cancer cell line (R. Clarke et al., Proc. Natl. Acad. Sci. USA 86: 3649-3653, 1989) was further passaged in ovariectomized nude mice and re-established in vitro as the continuous cell line MCF7/LCCI. The lag time to the appearance of proliferating tumors in ovariectomized animal...

Translationally controlled tumor protein (TCTP) is an evolutionally highly conserved protein which has been implicated in many cellular functions that are related to cell growth, death and tumorigenesis. We used a DNA vector-based RNA interference approach by expressing shRNA to knockdown TCTP in MCF7 cells for evaluating its antitumor effect and its molecular mechanism. TCTP shRNA treatment MC...