TY - JOUR
T1 - Effects of liposome-entrapped annamycin in human breast cancer cells
T2 - Interference with cell cycle progression and induction of apoptosis
AU - Orlandi, Linda
AU - Bertoli, Gloria
AU - Abolafio, Gabriella
AU - Daidone, Maria Grazia
AU - Zaffaroni, Nadia
PY - 2001
Y1 - 2001
N2 - The effects of liposome-encapsulated annamycin (L-Ann) were investigated in two human breast cancer cell lines, MCF7 and MDA-MB-435. For comparative purposes, doxorubicin (Dx) was used throughout the study. A 4-hour treatment with L-Ann was significantly more active in MDA-MB-435 than in MCF7 cells (IC50 values of 0.03 and 0.08 μg/ml, respectively), whereas Dx was equally active in the two cell lines (IC50 0.12 μg/ml). L-Ann induced an accumulation of cells in G2M phases which was dose-dependent in MDA-MB-435 but not in MCF7 cells. Dx also caused a dose-dependent increase of G2M cell fraction in MDA-MB-435 cells, whereas a G2M cell accumulation was observed only after treatment with the highest Dx concentration in MCF7 cells. G2M phase cell accumulations induced in MCF7 cells by L-Ann or Dx were accompanied by a decrease in cdc2 kinase activity and in cyclin B1 and cdc2 expression. Conversely, in MDA-MB-435 cells exposed to L-Ann or Dx, cdc2 kinase activity, cyclin B1 and cdc2 expression increased in parallel to the increase in the number of cells accumulated in the G2M phase. L-Ann and Dx induced apoptosis in MDA-MB-435 but not in MCF7 cells. In MDA-MB-435 cells exposed to L-Ann or Dx, no change was observed in the expression of bax, but there was a p53-independent increase in p21waf1 expression. In MCF7 cells, treatment with L-Ann or Dx induced an increase in p53 expression with a consequent transactivation of p21waf1 and bax. Our results indicate that L-Ann is more cytotoxic than Dx in breast cancer cells and is able to induce apoptosis through p53-independent mechanisms.
AB - The effects of liposome-encapsulated annamycin (L-Ann) were investigated in two human breast cancer cell lines, MCF7 and MDA-MB-435. For comparative purposes, doxorubicin (Dx) was used throughout the study. A 4-hour treatment with L-Ann was significantly more active in MDA-MB-435 than in MCF7 cells (IC50 values of 0.03 and 0.08 μg/ml, respectively), whereas Dx was equally active in the two cell lines (IC50 0.12 μg/ml). L-Ann induced an accumulation of cells in G2M phases which was dose-dependent in MDA-MB-435 but not in MCF7 cells. Dx also caused a dose-dependent increase of G2M cell fraction in MDA-MB-435 cells, whereas a G2M cell accumulation was observed only after treatment with the highest Dx concentration in MCF7 cells. G2M phase cell accumulations induced in MCF7 cells by L-Ann or Dx were accompanied by a decrease in cdc2 kinase activity and in cyclin B1 and cdc2 expression. Conversely, in MDA-MB-435 cells exposed to L-Ann or Dx, cdc2 kinase activity, cyclin B1 and cdc2 expression increased in parallel to the increase in the number of cells accumulated in the G2M phase. L-Ann and Dx induced apoptosis in MDA-MB-435 but not in MCF7 cells. In MDA-MB-435 cells exposed to L-Ann or Dx, no change was observed in the expression of bax, but there was a p53-independent increase in p21waf1 expression. In MCF7 cells, treatment with L-Ann or Dx induced an increase in p53 expression with a consequent transactivation of p21waf1 and bax. Our results indicate that L-Ann is more cytotoxic than Dx in breast cancer cells and is able to induce apoptosis through p53-independent mechanisms.
KW - Anthracyclines
KW - cdc2 kinase
KW - Cell proliferation
KW - Flow cytometry
KW - p53
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U2 - 10.1002/1097-4644(20010401)81:1<9::AID-JCB1020>3.0.CO;2-C
DO - 10.1002/1097-4644(20010401)81:1<9::AID-JCB1020>3.0.CO;2-C
M3 - Article
C2 - 11180394
AN - SCOPUS:0035089655
VL - 81
SP - 9
EP - 22
JO - Journal of Cellular Biochemistry
JF - Journal of Cellular Biochemistry
SN - 0730-2312
IS - 1
ER -