TY - JOUR
T1 - Involvement of BH4 domain of bcl-2 in the regulation of HIF-1-mediated VEGF expression in hypoxic tumor cells
AU - Trisciuoglio, D.
AU - Gabellini, C.
AU - Desideri, M.
AU - Ragazzoni, Y.
AU - De Luca, T.
AU - Ziparo, E.
AU - Del Bufalo, D.
PY - 2011/6
Y1 - 2011/6
N2 - In addition to act as an antiapoptotic protein, B-cell lymphoma (bcl)-2 can also promote tumor angiogenesis. In this context, we have previously demonstrated that under hypoxia bcl-2 promotes hypoxia-inducible factor-1 (HIF-1)-mediated vascular endothelial growth factor (VEGF) expression in melanoma and breast carcinoma. Here, we report on the role of the BH4 domain in bcl-2 functions, by showing that removal of or mutations at the BH4 domain abrogate the ability of bcl-2 to induce VEGF protein expression and transcriptional activity under hypoxia in human melanoma cells. We have also extended this observation to other human tumor histotypes, such as colon, ovarian and lung carcinomas. The involvement of BH4 on HIF-1α protein expression, stability, ubiquitination and HIF-1 transcriptional activity was also demonstrated in melanoma experimental model. Moreover, we validated the role of the BH4 domain of bcl-2 in the regulation of HIF-1/VEGF axis, demonstrating that BH4 peptide is sufficient to increase HIF-1α protein half-life impairing HIF-1α protein ubiquitination, and to enhance VEGF secretion in melanoma cells exposed to hypoxia. Finally, we found that the mechanism by which bcl-2 regulates HIF-1-mediated VEGF expression does not require BH1 and BH2 domains, and it is independent of antiapoptotic and prosurvival function of bcl-2.
AB - In addition to act as an antiapoptotic protein, B-cell lymphoma (bcl)-2 can also promote tumor angiogenesis. In this context, we have previously demonstrated that under hypoxia bcl-2 promotes hypoxia-inducible factor-1 (HIF-1)-mediated vascular endothelial growth factor (VEGF) expression in melanoma and breast carcinoma. Here, we report on the role of the BH4 domain in bcl-2 functions, by showing that removal of or mutations at the BH4 domain abrogate the ability of bcl-2 to induce VEGF protein expression and transcriptional activity under hypoxia in human melanoma cells. We have also extended this observation to other human tumor histotypes, such as colon, ovarian and lung carcinomas. The involvement of BH4 on HIF-1α protein expression, stability, ubiquitination and HIF-1 transcriptional activity was also demonstrated in melanoma experimental model. Moreover, we validated the role of the BH4 domain of bcl-2 in the regulation of HIF-1/VEGF axis, demonstrating that BH4 peptide is sufficient to increase HIF-1α protein half-life impairing HIF-1α protein ubiquitination, and to enhance VEGF secretion in melanoma cells exposed to hypoxia. Finally, we found that the mechanism by which bcl-2 regulates HIF-1-mediated VEGF expression does not require BH1 and BH2 domains, and it is independent of antiapoptotic and prosurvival function of bcl-2.
KW - bcl-2
KW - BH domain
KW - cancer
KW - HIF-1
KW - VEGF
UR - http://www.scopus.com/inward/record.url?scp=79955805684&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79955805684&partnerID=8YFLogxK
U2 - 10.1038/cdd.2010.175
DO - 10.1038/cdd.2010.175
M3 - Article
C2 - 21233846
AN - SCOPUS:79955805684
VL - 18
SP - 1024
EP - 1035
JO - Cell Death and Differentiation
JF - Cell Death and Differentiation
SN - 1350-9047
IS - 6
ER -