Although the anti-apoptotic effect of Bcl-2 is well established, the role of Bcl-2 in tumour response to therapy and drug resistance is still unclear. The posttranslational modifications of Bcl-2 are likely involved in the control of the apoptotic pathway. In the present study we have investigated the role of Bcl-2 in cellular response to oxidative stress (hydrogen peroxide) and cisplatin using a clone of human metastatic melanoma, which, in spite of Bcl-2 (over)expression, exhibited a moderate chemosensitivity. With both treatments melanoma cells died through an apoptotic process, associated with detachment of cells from the monolayer. In the floating apoptotic cells generated by either hydrogen peroxide or cisplatin, along with morphological and biochemical features of apoptosis, we detected a significant Bcl-2 cleavage, yielding the Bax-like fragment of 23 kDa. Preincubation of cells with the caspase-3/-7 inhibitor DEVD-CHO completely suppressed Bcl-2 cleavage, thus confirming that such a specific proteolysis requires activation of caspase-3/-7. The oxidant- and cisplatin-induced processing of Bcl-2 documented in the present study may represent a regulatory mechanism to circumvent the survival function of Bcl-2 upon apoptosis triggering and to enhance apoptotic response. Since the Bcl-2 cleavage should be regarded as a pro-apoptotic event, Bcl-2 expression is expected to increase susceptibility to apoptosis. Thus, such a pathway could be exploited to improve the efficacy of cytotoxic therapy of melanomas expressing Bcl-2.
DEL BELLO, B., Valentini, M.A., Zunino, F., Comporti, M., Maellaro, E. (2001). Cleavage of Bcl-2 in oxidant- and cisplatin-induced apoptosis of human melanoma cells. ONCOGENE, 20(33), 4591-4595 [10.1038/sj.onc.1204618].
Cleavage of Bcl-2 in oxidant- and cisplatin-induced apoptosis of human melanoma cells
COMPORTI, MARIO;MAELLARO, EMILIA
2001-01-01
Abstract
Although the anti-apoptotic effect of Bcl-2 is well established, the role of Bcl-2 in tumour response to therapy and drug resistance is still unclear. The posttranslational modifications of Bcl-2 are likely involved in the control of the apoptotic pathway. In the present study we have investigated the role of Bcl-2 in cellular response to oxidative stress (hydrogen peroxide) and cisplatin using a clone of human metastatic melanoma, which, in spite of Bcl-2 (over)expression, exhibited a moderate chemosensitivity. With both treatments melanoma cells died through an apoptotic process, associated with detachment of cells from the monolayer. In the floating apoptotic cells generated by either hydrogen peroxide or cisplatin, along with morphological and biochemical features of apoptosis, we detected a significant Bcl-2 cleavage, yielding the Bax-like fragment of 23 kDa. Preincubation of cells with the caspase-3/-7 inhibitor DEVD-CHO completely suppressed Bcl-2 cleavage, thus confirming that such a specific proteolysis requires activation of caspase-3/-7. The oxidant- and cisplatin-induced processing of Bcl-2 documented in the present study may represent a regulatory mechanism to circumvent the survival function of Bcl-2 upon apoptosis triggering and to enhance apoptotic response. Since the Bcl-2 cleavage should be regarded as a pro-apoptotic event, Bcl-2 expression is expected to increase susceptibility to apoptosis. Thus, such a pathway could be exploited to improve the efficacy of cytotoxic therapy of melanomas expressing Bcl-2.File | Dimensione | Formato | |
---|---|---|---|
nature.pdf
non disponibili
Tipologia:
PDF editoriale
Licenza:
NON PUBBLICO - Accesso privato/ristretto
Dimensione
390.96 kB
Formato
Adobe PDF
|
390.96 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
https://hdl.handle.net/11365/18997
Attenzione
Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo