Department of Nephrology, Beijing Children's Hospital, Capital Medical University, Beijing 100045, China.
Chin Med J (Engl). 2012 May;125(10):1733-9.
Wilms' tumor (nephroblastoma) is the most common pediatric kidney cancer. Only one Wilms' tumor gene is known, WT1 at 11p13, which is mutated in 5% - 10% of Wilms' tumors. Recently, mutations were reported in WTX at Xq11.1 in Wilms' tumors. This study investigated the mutation proportion, type, and distribution in WTX and WT1 in children with Wilms' tumor. The role of WTX/WT1 in the development of Wilms' tumor, and the relationship between clinical phenotype and genotype, were also studied.
Wilms' tumor specimens (blood samples from 70 patients and tumor tissue samples from 52 patients) were used. A long fragment of WTX and 10 exons and intron sequences of WT1 were amplified by polymerase chain reaction (PCR) from extracted genomic DNA and sequenced. A chi-square test compared the difference between the WTX mutation group and the no mutation group. The relationship between the mutations and clinical phenotype was analyzed.
WTX mutations were found in 5/52 tumor tissues and in 2/70 peripheral blood samples (five cases in total, all point mutations). Two patients had a WTX mutation in both samples. WT1 mutations were found in 2/52 tumor tissues and in 4/70 peripheral blood samples (five cases in total, all point mutations). One patient had a WT1 mutation in both samples. Ten cases had WTX or WT1 mutation (19.2% of Wilms' tumors). No overlapping WTX and WT1 mutations were found. No significant differences in clinical parameters were found between patients with and without a WTX mutation.
WTX mutations occur early in Wilms' tumor development, but at a low proportion. There was no evidence that WTX is the main cause of Wilms' tumor. Clinical parameters of patients with WTX mutations are not related to the mutation, indicating a limited impact of WTX on tumor progression. WTX and WT1 mutations occur independently, suggesting a relationship between their gene products.
肾母细胞瘤（Wilms 瘤）是最常见的小儿肾恶性肿瘤。目前仅发现一个 Wilms 瘤基因，即 11p13 上的 WT1，在 5%-10%的 Wilms 瘤中发生突变。最近，在 Wilms 瘤中发现了 Xq11.1 上的 WTX 突变。本研究调查了 WT1 和 WTX 基因突变在小儿肾母细胞瘤中的比例、类型和分布。同时还研究了 WTX/WT1 在 Wilms 瘤发生中的作用，以及临床表型与基因型的关系。
采用肾母细胞瘤标本（70 例患者的外周血样本和 52 例患者的肿瘤组织样本）。用聚合酶链反应（PCR）从提取的基因组 DNA 中扩增 WTX 大片段和 WT1 的 10 个外显子和内含子序列，并进行测序。采用卡方检验比较 WTX 突变组与无突变组之间的差异。分析突变与临床表型的关系。
在 52 例肿瘤组织和 70 例外周血样本中发现了 WTX 突变（共 5 例，均为点突变）。2 例患者在两个样本中均有 WTX 突变。在 52 例肿瘤组织和 70 例外周血样本中发现了 WT1 突变（共 5 例，均为点突变）。1 例患者在两个样本中均有 WT1 突变。WTX 或 WT1 突变共 10 例（占 Wilms 瘤的 19.2%）。未发现 WTX 和 WT1 突变重叠。WTX 突变患者与无突变患者的临床参数无显著差异。
WTX 突变发生在 Wilms 瘤发展的早期，但比例较低。没有证据表明 WTX 是 Wilms 瘤的主要原因。WTX 突变患者的临床参数与突变无关，表明 WTX 对肿瘤进展的影响有限。WTX 和 WT1 突变是独立发生的，提示它们的基因产物之间存在关系。
