Inhibitors of multidrug resistance to antitumor agents (MDR)

Area of Science:

• Oncology
• Pharmacology
• Molecular Biology

Background:

• Multidrug resistance (MDR) is a significant challenge in cancer chemotherapy, limiting the efficacy of antitumor drugs.
• MDR often involves the action of membrane transport proteins, such as P-glycoprotein (P-gp) and multidrug resistance-associated proteins (MRPs), which actively pump drugs out of cancer cells.
• Alternative mechanisms of MDR include alterations in protein phosphorylation and gene expression (mdr1, mrp1).

Purpose of the Study:

• To review and classify known multidrug resistance modulators used in cancer chemotherapy.
• To explore the mechanisms by which these modulators inhibit drug efflux and overcome MDR.
• To discuss structure-activity relationships among MDR modulators, despite their chemical diversity.

Main Methods:

• Classification of multidrug resistance modulators based on their chemical structures.
• Analysis of studies investigating the mechanisms of action of MDR modulators.
• Review of structure-activity relationship data for homogeneous series of MDR modulators.

Main Results:

• MDR modulators primarily function by inhibiting the activity of efflux pumps like P-gp and MRP.
• Some modulators operate through indirect mechanisms, affecting protein phosphorylation or gene expression related to MDR.
• Despite structural heterogeneity, structure-activity relationship studies on specific compound classes have yielded insights.

Conclusions:

• Developing safe and potent MDR reversal agents is crucial for improving cancer chemotherapy outcomes.
• Understanding the diverse mechanisms of MDR modulators is key to designing effective combination therapies.
• Further research into structure-activity relationships within specific chemical classes may lead to more targeted and effective MDR inhibitors.