American Society of Hematology

Fig. 10.

$Fig. 10. Multiparameter analysis demonstrates differing effect of NFκB inhibition and resultant c-IAP2 depletion toward induced PARP cleavage as a manifestation of apoptosis within resistant BCR-ABL A54 cells with abundant bcl-xL versus sensitive H7gag-akt/RafCAAX cells with minimal bcl-xL expression. / (A) Lysates were prepared from the noted cell types either without prior treatment or after treatment for 24 hours with parthenolide, and then they were immunoblotted with anti-PARP. Cells transformed by gag-akt/RafCAAX showed induced PARP degradation to generate an 85-kd PARP species, but those transformed by p210BCR-ABL were refractory to this treatment and retained their unmodified 116-kd PARP species intact. (B) Treatment of BCR-ABL.A54 cells and of H7gag-akt/RafCAAX cells with parthenolide was performed, and at various time intervals, lysates were prepared for immunoblotting of c-IAP2 expression. Loss of c-IAP2 expression was noted to have occurred in BCR-ABL.A54 cells by 16 hours (27% reduction by densitometry), and the loss was more extensive at 24 hours (56% reduction). In the case of H7gag-akt/RafCAAX cells, the inhibition of c-IAP2 expression by parthenolide was quite marked at 16 hours (64% reduction) and inhibition was total at 24 hours; in addition, the latter cells yielded lower total protein (controlled for by GAPDH expression), which was devoid of c-IAP2 associated with extensive apoptosis. (C) Lysates prepared from BCR-ABL.A54 cells or H7gag-akt/RafCAAX1 cells either untreated or treated for the indicated periods with parthenolide were immunoblotted for bcl-xL. There was high expression of bcl-xL in BCR-ABL.A54 cells and very little bcl-xL in H7gag-akt/RafCAAX cells. Neither cell type evidenced inhibition of bcl-xL expression by parthenolide treatment.$

Multiparameter analysis demonstrates differing effect of NFκB inhibition and resultant c-IAP2 depletion toward induced PARP cleavage as a manifestation of apoptosis within resistant BCR-ABL A54 cells with abundant bcl-xL versus sensitive H7gag-akt/RafCAAX cells with minimal bcl-xL expression.

(A) Lysates were prepared from the noted cell types either without prior treatment or after treatment for 24 hours with parthenolide, and then they were immunoblotted with anti-PARP. Cells transformed by gag-akt/RafCAAX showed induced PARP degradation to generate an 85-kd PARP species, but those transformed by p210BCR-ABL were refractory to this treatment and retained their unmodified 116-kd PARP species intact. (B) Treatment of BCR-ABL.A54 cells and of H7gag-akt/RafCAAX cells with parthenolide was performed, and at various time intervals, lysates were prepared for immunoblotting of c-IAP2 expression. Loss of c-IAP2 expression was noted to have occurred in BCR-ABL.A54 cells by 16 hours (27% reduction by densitometry), and the loss was more extensive at 24 hours (56% reduction). In the case of H7gag-akt/RafCAAX cells, the inhibition of c-IAP2 expression by parthenolide was quite marked at 16 hours (64% reduction) and inhibition was total at 24 hours; in addition, the latter cells yielded lower total protein (controlled for by GAPDH expression), which was devoid of c-IAP2 associated with extensive apoptosis. (C) Lysates prepared from BCR-ABL.A54 cells or H7gag-akt/RafCAAX1 cells either untreated or treated for the indicated periods with parthenolide were immunoblotted for bcl-xL. There was high expression of bcl-xL in BCR-ABL.A54 cells and very little bcl-xL in H7gag-akt/RafCAAX cells. Neither cell type evidenced inhibition of bcl-xL expression by parthenolide treatment.

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