AIM

To compare the molecular profile and cell cycle of sensitive and resistant to doxorubicin MCF-7 breast cancer cells upon exposition to conventional or liposome-encapsulated forms of doxorubicin.

METHODS

capital EM, Cyrilliccapital TE, Cyrilliccapital TE, Cyrillic-test, immunocytochemistry, flow cytometry.

RESULTS

In sensitive MCF-7 cells the exposure to conventional but not liposomal form of doxorubicin decreased metallothionein (MT) expression demonstrating activation of MT-detoxification system. In doxorubicin-resistant cells (MCF-7/Dsmall o, Cyrillicsmall ha, Cyrillic) MT expression drastically decreased. Conventional but not liposomal form of doxorubicin reduced the levels of expression of steroid hormones receptors on MCF-7 sensitive cells. The exposure of MCF-7 cells to conventional form of doxorubicin resulted in the decrease of p53 expression and the increase of Bcl-2 expression. In MCF-7/Dsmall o, Cyrillicsmall ha, Cyrillic cells neither conventional nor liposomal form of doxorubicin altered Bcl-2 expression. The exposure of MCF-7 but not MCF-7/Dsmall o, Cyrillicsmall ha, Cyrillic to doxorubicin in conventional form caused cell cycle arrest in G0/G1. Upon exposure to doxorubicin in liposomal form, cell cycle blockage in G0/G1 phase was observed in both sensitive and resistant sublines.

CONCLUSION

The differential effects of the conventional and liposomal forms of doxorubicin in sensitive and resistant cells have been demonstrated. Exposure of MCF-7 and MCF-7/Dsmall o, Cyrillicsmall ha, Cyrillic cells to doxorubicin in liposomal form alters the molecular profile and cell distribution over cell cycle phases.