conclusions these outcomes support our theory that rapamycin increases oxidative stress in mcf-7 and mda mb-231 cells but also shows high levels of antioxidant effects, which probably limit the effects of the rapamycin on the same issue in the clinic. methods the mcf-7 and mda mb-231 cell lines were cultivated and treated with rapamycin for 72 hours. the viability of the cells was determined us...

The purpose of present study was to investigate the effect of dioscin on activity of adriamycin (ADR) in ADR-sensitive (MCF-7) and ADR-resistant (MCF-7/ADR) human breast cancer cells and to clarify the molecular mechanisms involved. Antiproliferation effect of ADR was enhanced by dioscin in MCF-7 and MCF-7/ADR cells. Dioscin significantly inhibited MDR1 mRNA and protein expression and MDR1 prom...

New potential chemotherapeutic strategies are required to overcome multidrug resistance (MDR) in cancer. This study investigated the anticancer effect of a novel anthracene derivative MHY412 on doxorubicin-resistant human breast cancer (MCF-7/Adr) cells. We measured cell viability and the expression of apoptosis-related genes; in addition, the antitumor activity of MHY412 was confirmed using an...

Backgrounds: Evidence is accumulating to support disruption of tissue architecture as a powerful event in tumor formation. For the past four decades, intensive cancer research with the premise of “cancer as a cell based-disease” focused on finding oncogenes or tumor suppressor genes. However, the role of the tissue architecture was neglected. Three dimensional (3D) cell cultures which can recap...

This study was designed to investigate the role of protein kinase C (PKC) and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling in tamoxifen (TAM)-induced apoptosis and drug resistance in human breast cancer cells. Drug-sensitive, or estrogen receptor (ER)-positive human breast carcinoma cells (MCF-7) and the multi-drug-resistant variant (ER-negative) MCF-7/ADR cells were treated wit...

BACKGROUND Several mechanisms are known to cause resistance to chemotherapy in cancer cells, but the mechanisms of drug resistance due to a lack of apoptosis are not well elucidated. MATERIALS AND METHODS To understand the mechanisms of resistance to apoptosis induced by doxorubicin (DOX), we developed a DOX-resistant variant of MCF-7 referred to as MCF-7/Adr-20, measured growth inhibition by...

BACKGROUNDS Evidence is accumulating to support disruption of tissue architecture as a powerful event in tumor formation. For the past four decades, intensive cancer research with the premise of "cancer as a cell based-disease" focused on finding oncogenes or tumor suppressor genes. However, the role of the tissue architecture was neglected. Three dimensional (3D) cell cultures which can recapi...

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...

Objectives: 7-prenyloxycoumarins are a group of secondary metabolites that are found mainly in plants belonging to the Rutaceae and Umbelliferae families. This study was designed to evaluate and compare the cytotoxic and apoptotic activity of 7-prenyloxycoumarin compounds and herniarin on MCF-7, a breast carcinoma cell line. Materials and Methods: Cells were cultured in RPMI medium and incubate...