Multidrug resistance (MDR), as is well known, regarded the primary factor in cancer therapy failure. A common mechanism of MDR anticancer drugs expression P-glycoprotein (P-gp), a class ATP-dependent membrane transport efflux pumps called adenosine triphosphate (ATP)-binding cassette (ABC) transporters. It xenobiotics outside cell and plays part typical physiological detoxification host defense...

Conventional cancer chemotherapy is seriously limited by tumor cells exhibiting multidrug resistance (MDR), caused by changes in the level or activity of membrane transporters that mediate energy-dependent drug efflux and of other proteins that affect drug metabolism and/or drug action. Many inhibitors of MDR transporters have been identified and some are undergoing clinical trials, but current...

This study examined the effects of suppressing c-fos oncogene expression on multidrug resistance (MDR). A2780S human ovarian carcinoma cells with resistance to actinomycin D were isolated and the resultant A2780AD cells exhibited the MDR phenotype. A hammerhead ribozyme designed to cleave fos RNA cloned into the pMAMneo plasmid was transfected into A2780AD cells. Induction of the ribozyme resul...

The heterogeneous nature of an adriamycin-selected human MDR squamous lung cell line, DLKP-A, was investigated by isolating and characterising 9 of its clonal subpopulations. The DLKP-A cell line exhibits resistance to the classical MDR drugs, overexpresses P-glycoprotein and displays reduced topoisomerase II amounts. The clonal cell lines exhibit a wide range of resistance extents, with the mo...

Multidrug resistance (MDR) is a primary hindrance to curative cancer chemotherapy. In this respect, lysosomes were suggested to play a role in intrinsic MDR by sequestering protonated hydrophobic weak base chemotherapeutics away from their intracellular target sites. Here we show that intrinsic resistance to sunitinib, a hydrophobic weak base tyrosine kinase inhibitor known to accumulate in lys...

The recent treatment of hematological malignancies appears to be unsatisfactory in child and adult patients with acute myeloid leukemia and adult patients with acute lymphocytic leukemia. A major problem in the treatment of leukemia is caused by the development of drug resistance to chemotherapeutic agents, which is already present at diagnosis or after chemotherapy as a minimal residual diseas...

The recent emergence of multidrug resistance (MDR) in Acinetobacter baumannii has raised concern in health care settings worldwide. In order to understand the repertoire of resistance determinants and their organization and origins, we compared the genome sequences of three MDR and three drug-susceptible A. baumannii isolates. The entire MDR phenotype can be explained by the acquisition of disc...

Multiple-drug-resistant Mycobacterium tuberculosis (MDR-MTB) has been well studied in hospitals or health care institutions and in human immunodeficiency virus-infected populations. However, the characteristics of MDR-MTB in the community have not been well investigated. An understanding of its prevalence and circulation within the community will help to estimate the problem and optimize the st...

P-glycoprotein (Pgp), a membrane transporter encoded by the MDR1 gene in human cells, mediates drug efflux from cells, and it plays a major role in causing multidrug resistance (MDR). Confocal microscopy was used to study in vitro and in vivo drug accumulation, net uptake and efflux, and MDR modulation by P-glycoprotein inhibitors in MDR1-transduced human MDA-MB-435mdr (MDR) cancer cells. The M...