Vege Świat

[Kelly Robbins]

3 , collectively, indicate that GBM apoptosis is positively regulated rihanna puma slides by PUMA and negatively impacted by EGFR/EGFRvIII, suggesting that PUMA and EGFR/EGFRvIII pathways are functionally but inversely linked to apoptosis in GBM cells.The results in Fig. 4 indicate that, in GBM cells, EGFR/EGFRvIII and PUMA form complex constitutively under unstressed conditions and that the complex is sustained even following treatment with the apoptosis-inducer, staurosporin (ST).

The mtPUMA indices in these cells are 1.0, indicating that PUMA is exclusively detected on the mitochondria of these cells, independent of apoptotic stress. (C) EGFR expression knockdown by siRNA leads to increased PUMA mitochondrial translocalization. In control siRNA-treated puma fenty slides T98G natural GBM cells, PUMA is primarily localized in the cytoplasm. In EGFR-specific siRNA-treated cells, we observed a marked increase of mitochondrial PUMA (left panel).

EGFR-specific siRNA was effective in reducing EGFR expression as puma shoes for women shown by the western blots (right panel). Lamin B: nuclear protein. ME: mitochondrial extracts. NME: non-mitochondrial extracts. (D) PUMA is sequestered in the cytoplasm of EGFR-expressing human breast cancer cells. MDA-MB-468 cells, known to express high levels of endogenous EGFR [ 34 ], were treated with and without staurosporin, fractionated into mitochondrial and non-mitochondrial fractions and protein extracts analyzed as described earlier.

PUMA is primarily localized in the rihanna puma shoes cytoplasm of these cells, under unstressed and stressed conditions, as indicated by the low mtPUMA indices.Similar observations were further found in T98G GBM cells that naturally express EGFR ( Fig. 5c ). The modest detection of mitochondrial PUMA in these cells may potentially be the result of insufficient cytoplasmic EGFR to interact with and sequester all the PUMA molecules in the cytoplasm.

Importantly, siRNA-mediated EGFR expression knockdown led to a significant increase (16-fold) of mitochondrial PUMA ( Fig. 5c-left ), further suggesting the ability of EGFR to modulate PUMA mitochondrial translocalization. EGFR-specific siRNA was effective in reducing EGFR expression as shown by the western puma blaze of glory blots ( Fig. 5c-right ). In addition to GBM cells, we found PUMA to be localized in the cytoplasm of MDA-MB-468 human breast cancer cells .

To further determine whether EGFR kinase activity is required for the EGFR-PUMA interaction, we treated U87MG-EGFR cells with a small molecular weight EGFR kinase inhibitor, Iressa, that is in clinical use to inhibit EGFR activity. As shown by Fig. 6b (left panel) , Iressa did not alter EGFR binding to PUMA but, as expected, significantly reduced the level of EGFR auto-phosphorylation/activation.EGFR-PUMA interaction is independent of [img]http://www.czcrush.com/images/detail/puma blaze of glory-230wmy.jpg[/img] ligand-mediated receptor activation and is sustained under EGFR inhibition.

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