DHCR24 gene expression is upregulated in melanoma metastases and associated to resistance to oxidative stress-induced apoptosis
DHCR24 gene expression is upregulated in melanoma metastases and associated to resistance to oxidative stress-induced apoptosis
复制标题
DOI：
10.1002/ijc.20885
复制
发表时间：
2005-06-10
影响因子：
6.4
通讯作者：
Rodolfo, M
中科院分区：
文献类型：
--
作者：
Di Stasi, D;Vallacchi, V;Rodolfo, M
通过消减杂交分离编码3 β-羟基甾醇Δ 24-还原酶（一种参与胆固醇生物合成的氧化还原酶）的DHCR 24基因，与从自体原发性肿瘤（S/P）获得的DHCR 24基因相比，DHCR 24基因在源自皮肤转移瘤（S/M2）的短期黑素瘤细胞系中高度表达。DHCR 24（别名seladin-1，diminuto/dwarf 1同系物）已被报道在神经元中作为抗凋亡因子。通过北方印迹的基因表达分析证实，与S/P细胞相比，DHCR 24在S/M2中上调5倍。在13125例转移性黑色素瘤和1/7例原发性黑色素瘤中通过实时PCR检测到高水平的DHCR 24基因表达，表明该基因的上调可能发生在黑色素瘤进展中。在S/M2细胞中，DHCR 24基因的高表达与抗过氧化氢诱导的氧化应激引发的凋亡有关。DHCR 24基因转移显示出保护黑色素瘤细胞免受H2 O2诱导的细胞毒性。虽然S/M2细胞中的胆固醇水平高于S/P细胞，但DHCR 24基因转移并不增加胆固醇含量。为了评估DHCR 24是否在黑素瘤转移中作为抗凋亡因子，在DHCR 24转染子中和在DHCR 24抑制剂U18666 A存在下测试化学治疗剂的细胞毒性作用。转染子中DHCR 24基因的高表达并没有导致对细胞毒性剂的更高抗性;用U18666 A处理在具有较低DHCR 24含量的S/P细胞中具有细胞毒性，并且仅当与H2 O2而不是与cysplatin或依托泊苷相关联时才显示出累加的细胞毒性作用，这表明DHCR 24保护作用是通过氧化应激特异性机制发挥的。(c)2005 Wiley-Liss，Inc.
The DHCR24 gene encoding for the 3 beta-hydroxysterol Delta 24-reductase, an oxidoreductase involved in cholesterol biosynthesis, was isolated by subtractive hybridization as highly expressed in a short-term melanoma cell line derived from a cutaneous metastases (S/M2) compared to that obtained from the autologous primary tumor (S/P). DHCR24 (alias seladin-1, diminuto/dwarf1 homolog) has been reported to act as an antiapoptotic factor in neurons. Gene expression analysis by Northern blot confirmed that DHCR24 was 5-fold upregulated in S/M2 compared to S/P cells. High levels of DHCR24 gene expression were detected in 13125 melanoma metastases and in 1/7 primary melanomas by realtime PCR, indicating that upregulation of this gene may occur in melanoma progression. In S/M2 cells, high DHCR24 gene expression associated with resistance to apoptosis triggered by oxidative stress induced by exposure to hydrogen peroxide. DHCR24 gene transfer was shown to protect melanoma cells from H2O2-induced cytotoxicity. Although higher cholesterol levels were shown in S/M2 cells compared to S/P cells, DHCR24 gene transfer did not increase cholesterol content. To evaluate whether DHCR24 acts as an antiapoptotic factor in melanoma metastases, the cytotoxic effect of chemotherapeutic agents was tested in DHCR24 transfectants and in the presence of a DHCR24 inhibitor, U18666A. High DHCR24 gene expression in transfectants did not result in a higher resistance to cytotoxic agents; treatment with U18666A was cytotoxic in S/P cells with a lower DHCR24 content and showed additive cytotoxic effect only when associated with H2O2 and not with cysplatin or etoposide, indicating that the DHCR24 protective effect is exerted through an oxidative stress-specific mechanism. (c) 2005 Wiley-Liss, Inc.