Expression and function of hypoxia inducible factor-1 alpha in human melanoma under non-hypoxic conditions.
Expression and function of hypoxia inducible factor-1 alpha in human melanoma under non-hypoxic conditions.
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DOI：
10.1186/1476-4598-8-104
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发表时间：
2009-11-17
期刊：
影响因子：
37.3
通讯作者：
Niles RM
中科院分区：
文献类型：
--
作者：
Mills CN;Joshi SS;Niles RM
缺氧诱导因子-1α (HIF-1α)蛋白在常氧条件下迅速降解。当氧张力下降时，HIF-1α蛋白稳定并激活参与适应缺氧条件的基因。我们检测了HIF-1α RNA和蛋白在正常人类黑色素细胞和一系列从放射状生长期（RGP）、垂直生长期（VGP）和转移性黑色素瘤中分离的人类黑色素瘤细胞系中的正常表达。RGP与黑素细胞、VGP与RGP、MET与VGP黑色素瘤细胞系中HIF-1α mRNA和蛋白表达升高。我们还在WM1366和WM9黑色素瘤细胞中检测到缺乏部分氧依赖调节结构域的HIF-1α mRNA剪接变体的表达。在RGP细胞系SbCl2中过表达HIF-1α及其剪接变体导致软琼脂集落形成的少量增加，而基质侵袭的大量增加。在MET WM9黑色素瘤细胞系中，用siRNA敲低HIF-1α的表达，与非特异性siRNA处理的细胞相比，软琼脂集落形成和基质侵袭均大幅减少。WM9细胞中ERK1/2高水平磷酸化，表明Ras-Raf-MEK-ERK1/2 MAPK通路被激活。用30 μM U0126 MEK抑制剂处理WM9细胞，ERK1/2磷酸化降低，HIF-1α表达降低。然而，10 μM U0126处理24 h完全消除Erk1/2磷酸化，但没有改变hif -1 α水平。此外，MEK siRNA的siRNA敲低并不会改变hif -1 α水平。我们推测U0126的代谢产物通过“脱靶”效应降低HIF-1alpha的表达。总的来说，我们的数据表明，常压条件下HIF-1α表达的增加有助于人类黑色素瘤细胞表现出的一些恶性表型。HIF-1α在黑色素瘤生物学中的扩展作用增加了其作为治疗靶点的重要性。
Hypoxia inducible factor-1 alpha (HIF-1α) protein is rapidly degraded under normoxic conditions. When oxygen tensions fall HIF-1α protein stabilizes and transactivates genes involved in adaptation to hypoxic conditions. We have examined the normoxic expression of HIF-1α RNA and protein in normal human melanocytes and a series of human melanoma cell lines isolated from radial growth phase (RGP), vertical growth phase (VGP) and metastatic (MET) melanomas. HIF-1α mRNA and protein was increased in RGP vs melanocytes, VGP vs RGP and MET vs VGP melanoma cell lines. We also detected expression of a HIF-1α mRNA splice variant that lacks part of the oxygen-dependent regulation domain in WM1366 and WM9 melanoma cells. Over-expression of HIF-1α and its splice variant in the RGP cell line SbCl2 resulted in a small increase in soft agar colony formation and a large increase in matrigel invasion relative to control transfected cells. Knockdown of HIF-1α expression by siRNA in the MET WM9 melanoma cell line resulted in a large decrease in both soft agar colony formation and matrigel invasion relative to cells treated with non-specific siRNA. There is a high level of ERK1/2 phosphorylation in WM9 cells, indicating an activated Ras-Raf-MEK-ERK1/2 MAPK pathway. Treatment of WM9 cells with 30 μM U0126 MEK inhibitor, decreased ERK1/2 phosphorylation and resulted in a decrease in HIF-1α expression. However, a 24 h treatment with 10 μM U0126 totally eliminated Erk1/2 phosphorylation, but did not change HIF-1alpha levels. Furthermore, siRNA knockdown of MEK siRNA did not change HIF-1alpha levels. We speculate that metabolic products of U0126 decrease HIF-1alpha expression through "off target" effects. Overall our data suggest that increased HIF-1α expression under normoxic conditions contributes to some of the malignant phenotypes exhibited by human melanoma cells. The expanded role of HIF-1α in melanoma biology increases its importance as a therapeutic target.
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DOI：
10.1158/1541-7786.mcr-07-2177
发表时间：
2008-07
期刊：
Molecular cancer research : MCR
影响因子：
--
作者：
Niu G;Briggs J;Deng J;Ma Y;Lee H;Kortylewski M;Kujawski M;Kay H;Cress WD;Jove R;Yu H
通讯作者：
Yu H
影响因子：
11.2
作者：
Liao, Debbie;Corle, Courtney;Johnson, Randall S.
通讯作者：
Johnson, Randall S.
影响因子：
64.8
作者：
Maxwell, PH;Wiesener, MS;Ratcliffe, PJ
通讯作者：
Ratcliffe, PJ
影响因子：
4.8
作者：
Favata, MF;Horiuchi, KY;Trzaskos, JM
通讯作者：
Trzaskos, JM
影响因子：
50.3
作者：
Houghton, AN;Polsky, D
通讯作者：
Polsky, D