Identification and functional characterization of ASK/Dbf4, a novel cell survival gene in cutaneous melanoma with prognostic relevance
Identification and functional characterization of ASK/Dbf4, a novel cell survival gene in cutaneous melanoma with prognostic relevance
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DOI：
10.1093/carcin/bgm197
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发表时间：
2007-12-01
期刊：
影响因子：
4.7
通讯作者：
Hengge, Ulrich R.
中科院分区：
文献类型：
--
作者：
Nambiar, Sandeep;Mirmohammadsadegh, Alireza;Hengge, Ulrich R.
恶性黑色素瘤是最具侵袭性和侵袭性的转移性肿瘤之一，其来源于通过获得遗传和表观遗传改变而经历恶性转化的黑素细胞。基于寡核苷酸微阵列的皮肤黑色素瘤肿瘤进展模型中不同阶段的筛选确定了ASK/Dbf 4作为黑色素瘤发展的新决定因素。对一系列良性痣、发育不良痣、原发性皮肤黑色素瘤和皮肤黑色素瘤转移灶进行基于定量实时聚合酶链反应的ASK/Dbf 4确认;以及使用正常人黑色素细胞作为校准物的许多其他对照不仅揭示了黑色素瘤特异性过表达，而且还揭示了较高的ASK/Dbf 4表达黑色素瘤与较低的无复发生存率相关。此外，我们还证实了所观察到的ASK/Dbf 4在黑色素瘤中的过度表达，使用蛋白质印迹分析和免疫组织化学。由于在酵母中的研究发现ASK/Dbf 4是哺乳动物Cdc 7的一个细胞周期蛋白样调节亚基，本研究探讨了其在黑色素瘤细胞中的作用。与其预期的作用保持一致，我们的数据表明，上调的ASK/Dbf 4定位于细胞核中，并与人Cdc 7结合，在几种分析的黑色素瘤细胞系中形成Cdc 7-ASK/Dbf 4复合物。此外，我们证明小干扰RNA介导的ASK/Dbf 4缺失会阻碍黑色素瘤细胞的存活和增殖。总之，我们报告了一个新的基因，即ASK/Dbf 4，在黑色素瘤的差异调节，并建议上调ASK/Dbf 4是一种新的分子决定因素与预后相关性，赋予皮肤黑色素瘤的增殖优势。
Malignant melanoma is one of the most aggressive and invasive metastatic tumors derived from melanocytes that have undergone malignant transformation by acquisition of genetic and epigenetic alterations. Oligonucleotide microarray-based screening of distinct stages in the tumor progression model of cutaneous melanoma identified ASK/Dbf4, as a novel determinant for melanoma development. Quantitative real-time polymerase chain reaction-based confirmation of ASK/Dbf4 on a series of benign nevi, dysplastic nevi, primary cutaneous melanomas and cutaneous melanoma metastases; and a number of other controls using normal human melanocytes as calibrator not only revealed a melanoma-specific over-expression but also revealed that higher ASK/Dbf4-expressing melanomas were associated with lower relapse-free survival. Additionally, we also confirmed the observed over-expression of ASK/Dbf4 in melanoma using western blot analysis and immunohistochemistry. As ASK/Dbf4 is known to be a cyclin-like regulatory subunit of mammalian Cdc7 from the studies in yeast, the present study investigated its role in melanoma cells. In keeping with its expected role, our data suggest that up-regulated ASK/Dbf4 is localized in the nucleus and binds to human Cdc7 to form Cdc7-ASK/Dbf4 complexes in several analyzed melanoma cell lines. Further, we demonstrate that small interfering RNA-mediated depletion of ASK/Dbf4 retarded melanoma cell survival and proliferation. In summary, we report the differential regulation of a novel gene, namely ASK/Dbf4, in melanoma and suggest that up-regulation of ASK/Dbf4 is a novel molecular determinant with prognostic relevance that confers a proliferative advantage in cutaneous melanoma.