Related Experiment Video
Updated: Sep 8, 2026

A Method for Screening and Validation of Resistant Mutations Against Kinase Inhibitors
Published on: December 7, 2014
[Vincristine-resistant human KB cell line and mechanism of multidrug resistance]
1Institute of Materia, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing.
Abstract:
A multidrug-resistant (mdr) clone of human cancer KB cells was isolated by stepwise selection on exposure to increasing doses of vincristine. The final clone, KBv200, obtained after ethylmethane sulfonate (EMS) mutagenesis showed 175-fold higher resistance to vincristine than did KB cells. The cells were also cross-resistant to taxol, colchicine and adriamycin. Cellular accumulation of vincristine in KBv200 was decreased to less than one-fifth of that in KB. To determine the presence of mdr 1 mRNA in KBv200 and KB, total cellular RNAs from each cell line were analyzed by means of slot blot hybridization. The result showed that the mdr 1 gene had been highly expressed in KBv200. In addition, verapamil, a calcium channel blockers, was shown to increase VCR accumulation in KBv200 and reverse the vincristine resistance. All these results demonstrate that the mechanism of KBv200 cell resistance to multiple drugs resulted from increased expression of mdr 1 gene and brought about over production of P-glycoprotein and increased the efflux of drugs.
More Related Videos
08:46Implementation of In Vitro Drug Resistance Assays: Maximizing the Potential for Uncovering Clinically Relevant Resistance Mechanisms
Published on: December 9, 2015
09:58Using RNA-sequencing to Detect Novel Splice Variants Related to Drug Resistance in In Vitro Cancer Models
Published on: December 9, 2016
Related Concept Videos
ABC Transporters: Exporter
Treatment Resistant Cancers
Combination Therapies and Personalized Medicine
The combination of the drug acetazolamide and sulforaphane is a good example of combination therapy to treat cancer. The cells in the interior of a large tumor often die due to the hypoxic and...
Drugs that Destabilize Microtubules
Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters
Mechanism of Antibiotic Resistance in MRSA