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Lipid raft modulation by Rp1 reverses multidrug resistance via inactivating MDR-1 and Src inhibition

Un-Jung Yun1, Ji-Hye Lee, Kyung Hee Koo

  • 1Comparative Biomedicine Research Branch, Division of Cancer Biology, Research Institute, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu, Goyang-si, Gyeonggi-do 410-769, Republic of Korea.

Biochemical Pharmacology
|March 12, 2013
PubMed

Insights

A novel ginsenoside derivative, Rp1, overcomes cancer multidrug resistance by modulating lipid rafts and decreasing MDR-1 transporter activity. This approach enhances chemotherapy effectiveness and reduces drug efflux from cancer cells.

Area of Science:

  • Oncology
  • Molecular Biology
  • Pharmacology

Background:

  • Multidrug resistance (MDR) is a significant challenge in cancer therapy, primarily driven by the MDR-1 (P-gp, ABCB1) transporter.
  • MDR-1 effluxes anti-cancer drugs from cancer cells and is localized in cholesterol-rich lipid rafts.
  • Cholesterol is critical for lipid raft function, and its depletion disrupts these microdomains.

Purpose of the Study:

  • To investigate the effect of Rp1, a novel ginsenoside derivative, on MDR-1 activity and cancer drug resistance.
  • To explore the role of lipid rafts in Rp1-mediated reversal of multidrug resistance.
  • To determine if Rp1 can sensitize cancer cells to chemotherapy.

Main Methods:

  • Utilized drug-sensitive (OVCAR-8) and drug-resistant (NCI/ADR-RES, DXR) cancer cell lines.
  • Assessed the impact of Rp1 on drug accumulation (doxorubicin, rhodamine 123) and cell death.
  • Investigated Rp1's effects on lipid raft redistribution, MDR-1 protein levels, and Src phosphorylation.
  • Examined the influence of cholesterol and Src activity on Rp1's efficacy.

Main Results:

  • Rp1 treatment decreased MDR-1 activity, leading to increased intracellular accumulation of anti-cancer drugs.
  • Rp1 synergistically enhanced cell death when combined with actinomycin D in resistant cells.
  • Rp1 modulated lipid raft structure and redistributed MDR-1 protein, reducing its levels and Src phosphorylation.
  • Cholesterol addition counteracted Rp1's effects on raft aggregation and MDR-1 redistribution.
  • Rp1 sensitized cells to various anti-cancer drugs, including doxorubicin.

Conclusions:

  • Rp1 effectively overcomes multidrug resistance by targeting lipid rafts and inhibiting MDR-1 transporter function.
  • Modulating lipid rafts with agents like Rp1 presents a promising strategy to enhance cancer chemotherapy efficacy.
  • Rp1 demonstrates potential as a sensitizer for multiple anti-cancer drugs, offering a new therapeutic avenue.

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