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Effects of drug combinations on smooth muscle cell proliferation: an isobolographic analysis

Tom J Parry1, Rathna Thyagarajan, Dennis Argentieri

  • 1Johnson and Johnson Pharmaceutical Research and Development, Welsh and McKean Roads, PO Box 776, Spring House, PA 19477, USA. tparry@prdus.jnj.com

European Journal of Pharmacology
|February 2, 2006
PubMed

Insights

Combining sirolimus with cladribine or topotecan enhances its ability to inhibit vascular smooth muscle cell proliferation, offering potential for improved restenosis prevention. Etoposide showed less potentiation, highlighting the importance of drug combination selection.

Area of Science:

  • Pharmacology
  • Cardiovascular Research
  • Cell Biology

Background:

  • Sirolimus effectively inhibits vascular smooth muscle cell (VSMC) proliferation, crucial for preventing restenosis after stenting.
  • Some VSMCs exhibit resistance to sirolimus, necessitating combination therapies for enhanced antiproliferative effects.

Purpose of the Study:

  • To investigate the synergistic effects of combining sirolimus with cladribine, topotecan, or etoposide on cultured coronary artery VSMC proliferation.
  • To determine if these drug combinations exhibit additive, subadditive, or supraadditive potentiation of antiproliferative activity using isobolographic analysis.

Main Methods:

  • Cultured human coronary artery smooth muscle cells were treated with sirolimus alone and in combination with cladribine, topotecan, or etoposide.
  • Cell proliferation was assessed in a dose-dependent manner.
  • Isobolugraphic analysis was employed to quantify the potentiation effects of drug combinations.

Main Results:

  • All tested agents (sirolimus, cladribine, topotecan, etoposide) inhibited VSMC proliferation dose-dependently.
  • Cladribine demonstrated additive or supraadditive potentiation of sirolimus's antiproliferative activity.
  • Topotecan showed additive potentiation, while etoposide exhibited subadditive potentiation with sirolimus.

Conclusions:

  • Combination therapy with sirolimus and cladribine or topotecan can enhance antiproliferative effects on VSMCs.
  • Isobolugraphic analysis is a valuable tool for identifying and optimizing synergistic drug combinations for cardiovascular applications.
  • The findings suggest potential for improved restenosis prevention strategies through rational drug combination selection.

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