Multidrug resistance is the major cause of chemotherapy failure in many solid tumors, including colon cancer. Hypoxic environment is a feature for all solid tumors and is important for the development of tumor resistance to chemotherapy. Hypoxia-inducible factor (HIF)-1α is the key transcription factor that mediates cellular response to hypoxia. HIF-1α has been shown to play an important role i...

A gene responsible for multidrug resistance was cloned from the chromosomal DNA of non-O1 Vibrio cholerae NCTC 4716 by using as a host drug-hypersensitive Escherichia coli strain KAM32, which lacks major multidrug efflux pumps. E. coli cells transformed with the gene showed elevated levels of resistance to a number of structurally dissimilar drugs, such as tetracycline, norfloxacin, ciprofloxac...

Chemoresistance is a major barrier to successful chemotherapy in canine lymphomas and mammary tumors. Several mechanisms have been shown to contribute to chemoresistance in a variety of cancers. One such mechanism is the overexpression of drug efflux pumps, called multidrug transporters, that result in reduced efficacy of chemotherapy drugs and thereby lead to chemoresistance. Nuclear receptors...

The VIM-1-producing multidrug-resistant strain Enterobacter cloacae was isolated from blood culture. The strain showed multiple resistances to clinically used antibiotics, including all β-lactams, fluoroquinolones, aminoglycosides, and sulfonamides. Sequence analysis showed the presence of 14 genes associated with resistance to antibiotics, including the metallo-β-lactamase VIM-1 gene, which wa...

The tumor cells' acquisition of resistance to multiple drugs due to overexpression of the multidrug resistance protein (MPRP)1 gene is one of major obstacles in cancer chemotherapy. We have attempted to reverse the multidrug resistance (MDR) phenotype by treating etoposide resistant glioma cell lines (T98G-VP and Gli36-VP) with RP1 antisense oligonucleotides. 20-mer phosphorothioate oligodeoxyn...

We have generated mice transgenic for a human multidrug resistance (MDR)3 mini-gene driven by a hamster vimentin promoter. The MDR3 gene encodes a P-Glycoprotein that resembles the mouse multidrug resistance 2 P-Glycoprotein shown to be involved in the translocation of the phospholipid phosphatidylcholine through the hepatocyte canalicular membrane (Smit et al., 1993. Cell. 75:451-462). The vim...

Surface water samples from downstream and estuarine areas of Jiulong River were collected in August 2011 and May 2012 for detecting sulfonamide antibiotic residues and isolating sulfamethazine-resistant bacteria. Sulfamethazine was detected in all samples in May 2012 at an average concentration of 78.3 ng L(-1), which was the highest among the nine sulfonamide antibiotics determined. Sulfametha...

A major problem with anti-cancer drug treatment is the development of acquired multidrug resistance (MDR) of the tumor cells. Verotoxin-1 (VT-1) exerts its cytotoxicity by targeting the globotriaosylceramide membrane receptor (Gb3), a glycolipid associated with multidrug resistance. Gb3 is overexpressed in many human tumors and tumor cell lines with inherent or acquired MDR. Gb3 is co-expressed...

The drug accumulation of a human multidrug resistance 1 (mdr1) gene-transfected mouse lymphoma cell line and a multidrug resistance protein (MRP)-expressing human breast cancer cell line MDA-MB-231 was compared in the presence of sixteen flavonoids and five isoflavonoids. The expression of the 170-kDa P-glycoprotein (P-gp) (MDR1) and 190-kDa multidrug resistance protein (MRP) in both cell lines...