Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.4.2.30 (PARP)
 13,611 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this work we tried to estimate the role of mitochondria in the ability of cells of two: melanotic and amelanotic transplantable melanoma lines to undergo spontaneous and camptothecin-induced apoptosis. We measured mitochondrial transmembrane potential (DeltaPsi) changes during culture without (spontaneous apoptosis) and with camptothecin (induced apoptosis) by using JC-1 staining and flow cytometry analysis. Cytochrome c release and PARP cleavage as the biological effects of DeltaPsim changes belonging to the phenomena observed during apoptosis were estimated by Western blotting. The results of our investigations showed in both transplantable melanoma cells the features indicating apoptosis: DeltaPsi changes, cytochrome c release and PARP cleavage, but the degree of observed changes depended on the phenotype of melanoma cells examined. After camptothecin treatment the changes were more pronounced in the amelanotic melanoma cells- the more aggressive line.
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PMID:Mitochondrial transmembrane potential in spontaneous and camptothecin-induced apoptosis of melanotic and amelanotic melanoma cells. 1720 90

Loss of pigment in hamster amelanotic melanoma line is accompanied by a faster growth rate, higher tumorigenicity and shorter animal survival time. Thus, the malignancy of melanoma increases during the alteration of melanotic (Ma) into amelanotic (Ab) line. As changes in the ability to undergo a spontaneous or induced apoptosis, and the role of caspases in this process during melanoma progression are not well defined, they were investigated in this work. Our results show that the proportion of spontaneously early apoptotic (caspase+/PI-) cells in the Ab line decreased in comparison to the Ma line. Cytochrome c release into cytosol, and the activation of effector caspases, estimated by PARP degradation clearly showed that during the spontaneous death in the cells from both melanoma lines intrinsic way of apoptosis was activated. Confocal and cytometric flow analyses indicate that camptothecin (CPT) induced apoptosis with caspase activation by the intrinsic way only in the amelanotic melanoma cells, even though cells of the Ma line also underwent CPT-induced apoptosis (the content of TUNEL-positive cells increased). Thus, our results suggest that melanoma progression, associated with a decreased ability to undergo spontaneous apoptosis but an increased susceptibility to CPT-induced apoptosis, relates to different levels of caspase activation; they also show that intrinsic way of apoptotis depends on the phenotype of melanoma cells, being more pronounced in the melanotic melanoma cells. On the other hand, melanotic melanoma cells resistance to camptothecin-induced apoptosis suggests that the melanogenic apparatus or melanin itself may have the protective effect on the ability of the melanoma cells to undergo apoptosis.
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PMID:The activity of caspases in spontaneous and camptothecin-induced death of melanotic and amelanotic melanoma cell. 1731 83