Overexpression of cdc25A and cdc25B is frequent in primary non-small cell lung cancer but is not associated with overexpression of c-myc.
Overexpression of cdc25A and cdc25B is frequent in primary non-small cell lung cancer but is not associated with overexpression of c-myc.
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发表时间：
1998-09
期刊：
影响因子：
11.2
通讯作者：
Weiguo Wu;Youhong Fan;B. Kemp;Garrett L. Walsh;Li Mao
中科院分区：
文献类型：
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作者：
Weiguo Wu;Youhong Fan;B. Kemp;Garrett L. Walsh;Li Mao
细胞周期蛋白依赖性激酶可以被cdc 25激活，cdc 25从酪氨酸和苏氨酸残基中去除抑制性磷酸盐。在人类中已经鉴定出至少三种cdc 25基因（cdc 25 A、cdc 25 B和cdc 25 C）。越来越多的证据表明cdc 25 A和cdc 25 B具有致癌特性。最近，cdc 25 A和cdc 25 B的过度表达被发现在许多乳腺癌和头颈癌。为了确定cdc 25在非小细胞肺癌（NSCLC）中的潜在作用，我们采用多重逆转录PCR（RT-PCR）分析了40例NSCLC患者的原发肿瘤和相应的正常肺组织中这些基因的相对表达水平。cdc 25 A在60%（24/40）的肿瘤中过表达，cdc 25 B在45%（18/40）的肿瘤中过表达，而cdc 25 C在所分析的任何肿瘤中均未过表达。由于c-myc可增加cdc 25 A和cdc 25 B的表达，因此c-myc可能是cdc 25过表达的一个因素。我们发现c-myc在只有18%（40例中的7例）的肿瘤中过表达。我们发现c-myc和cdc 25 A或cdc 25 B的过度表达之间没有关联。我们还调查了cdc 25 B基因是否在NSCLC中扩增，发现在40%（20例中的8例）的受试肿瘤中是如此。然而，这种扩增与基因表达状态无关。有趣的是，在24例cdc 25 A过表达和18例cdc 25 B过表达的肿瘤中，42%（10/24）和44%（8/18）为低分化组织学类型。相反，高分化或中等分化的肿瘤具有较低的cdc 25 A和cdc 25 B过表达频率[分别为19%（3/16）和23%（5/22）]。这些数据表明，cdc 25 A和cdc 25 B的过度表达是频繁的，它可能在NSCLC中发挥重要作用。然而，这种过度表达不太可能是由c-myc刺激或cdc 25 B基因扩增引起的。
Cyclin-dependent kinases can be activated by cdc25, which removes inhibitory phosphates from tyrosine and threonine residues. At least three cdc25 genes (cdc25A, cdc25B, and cdc25C) have been identified in humans. Accumulating evidence indicates that cdc25A and cdc25B possess oncogenic properties. Recently, overexpression of cdc25A and of cdc25B was found in many breast and head and neck cancers. To determine potential roles of cdc25s in non-small cell lung cancer (NSCLC), we analyzed primary tumors and corresponding normal lung tissues from 40 patients with NSCLC for relative expression levels of these genes by multiplex reverse transcription PCR (RT-PCR). cdc25A was overexpressed in 60% (24 of 40) of the tumors and cdc25B in 45% (18 of 40) of the tumors, whereas cdc25C was not overexpressed in any of the tumors analyzed. Because c-myc can increase cdc25A and cdc25B expression, it may be a factor in cdc25 overexpression. We found that c-myc was overexpressed in only 18% (7 of 40) of the tumors. We found no association between overexpression of c-myc and cdc25A or cdc25B. We also investigated whether the cdc25B gene was amplified in NSCLC and found this was true in 40% (8 of 20) of the tumors tested. However, this amplification was not correlated with gene expression status. Interestingly, among 24 tumors with cdc25A overexpression and 18 with cdc25B overexpression, 42% (10 of 24) and 44% (8 of 18) were poorly differentiated histological type. In contrast, well or moderately differentiated tumors had lower frequencies of cdc25A and cdc25B overexpression [19% (3 of 16) and 23% (5 of 22), respectively]. These data indicate that overexpression of cdc25A and cdc25B is frequent and that it may play an important role in NSCLC. However, it is unlikely that this overexpression is caused by c-myc stimulation or cdc25B gene amplification.