Huang Fung Yu, Chiu Pui Man, Tam Kar Fai, Kwok Yvonne K Y, Lau Elizabeth T, Tang Mary H Y, Ng Tong Yow, Liu Vincent W S, Cheung Annie N Y, Ngan Hextan Y S
Department of Obstetrics and Gynaecology, Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China.
Gynecol Oncol. 2006 Oct;103(1):219-25. doi: 10.1016/j.ygyno.2006.02.028. Epub 2006 Apr 3.
Comparative genomic hybridization has frequently detected amplification of chromosome 5p in cervical cancer, but candidate cancer genes within the region are rarely known. Therefore, we pursued to identify potential candidate gene related to cervical cancer development.
A series of 128 cervical tumor samples were examined by semi-quantitative fluorescent differential PCR for copy number changes on three candidate genes (PRKAA1, CTNND2 and POLS) mapped to chromosome 5p and one gene (ERBIN) mapped to chromosome 5q12.3. The impact of gene copy number was later analyzed in relation to HPV infection, tumor stage or tumor radiosensitivity.
DNA copy numbers of PRKAA1, CTNND2 and ERBIN were significantly different from normal controls (P < 0.05). DNA copy number changes did not correlate with HPV infection, tumor stages or tumor radiosensitivity. Using RT-PCR, PRKAA1 mRNA expression in seven tumor samples with known 5p amplification was amplified from 3- to 15-fold. Over-expression of PRKAA1 was further confirmed by immunohistochemical staining on 125 paraffin-embedded cervical cancer tissues. The expression level in cervical tumor was significantly higher than that in normal epithelium (P < 0.001).
PRKAA1 gene codes for the catalytic alpha 1 subunit of the AMP-activated protein kinase which is an important cellular metabolic stress regulator. It might assist tumor cells growth under stress. Thus, PRKAA1 may be one of the potential candidate genes for cervical carcinogenesis.
比较基因组杂交技术经常检测到宫颈癌中5号染色体短臂（5p）的扩增，但该区域内的候选癌基因却鲜为人知。因此，我们致力于鉴定与宫颈癌发生相关的潜在候选基因。
采用半定量荧光差异PCR检测了128例宫颈肿瘤样本中位于5号染色体短臂上的三个候选基因（PRKAA1、CTNND2和POLS）以及位于5号染色体长臂12.3区的一个基因（ERBIN）的拷贝数变化。随后分析了基因拷贝数与HPV感染、肿瘤分期或肿瘤放射敏感性之间的关系。
PRKAA1、CTNND2和ERBIN的DNA拷贝数与正常对照相比有显著差异（P < 0.05）。DNA拷贝数变化与HPV感染、肿瘤分期或肿瘤放射敏感性无关。使用RT-PCR，在7例已知5p扩增的肿瘤样本中，PRKAA1 mRNA表达扩增了3至15倍。通过对125例石蜡包埋的宫颈癌组织进行免疫组化染色进一步证实了PRKAA1的过表达。宫颈肿瘤中的表达水平显著高于正常上皮（P < 0.001）。
PRKAA1基因编码AMP激活蛋白激酶的催化α1亚基，该激酶是一种重要的细胞代谢应激调节因子。它可能在应激状态下协助肿瘤细胞生长。因此，PRKAA1可能是宫颈癌发生的潜在候选基因之一。
