Neoplasma. 2016;63(5):779-88. doi: 10.4149/neo_2016_516.
Oncogenic mutations in proto-oncogenes and tumor suppressor genes represent one of key events in cancerogenesis. In this study, we analysed mutation status in PIK3CA, KRAS and EGFR proto-oncogenes and TP53 tumor suppressor gene in a cohort of twenty-four patients diagnosed with squamous cell carcinoma or adenocarcinoma using the screening method "High Resolution Melting" (HRM). Positive findings were confirmed and identified by Sanger sequencing. Totally, we detected DNA sequence changes in targeted regions in seven patients (7/24, 29.2%). In PIK3CA gene, we found six sequence changes in four patients (4/24, 16.7%) and four of them were confirmed as oncogenic mutations. In KRAS gene, we detected sequence changes in four patients (4/24, 16.7%). Conversely, we identified pathogenic or potentially pathogenic sequence changes neither in EGFR nor TP53 genes. Our results suggest that sequence changes are specific neither for a certain histological subtype, clinical stage nor lymph node involvement and they appear independently on the presence of HPV (human papillomavirus) infection since early clinical stages. We observed the correlation between the presence of DNA sequence changes and hTERC gene amplification, but we did not find a significant relationship between the identified DNA sequence changes and detected copy-number alterations using the technique of array-CGH (array-based comparative genomic hybridization). Regardless our results confirmed an important role of oncogenic mutations in PIK3CA and KRAS genes in the neoplastic transformation process in the cervical carcinoma pathogenesis. Their identification in the early clinical stages should encourage further studies to better understand these mutations and exploit them for more detailed diagnostics.
原癌基因和肿瘤抑制基因中的致癌突变是癌症发生的关键事件之一。在这项研究中,我们使用“高分辨率熔解”(HRM)筛选方法分析了 24 例诊断为鳞状细胞癌或腺癌患者的 PIK3CA、KRAS 和 EGFR 原癌基因和 TP53 肿瘤抑制基因的突变状态。阳性发现通过 Sanger 测序得到证实和确认。总共,我们在 7 名患者(7/24,29.2%)中检测到了靶向区域的 DNA 序列变化。在 PIK3CA 基因中,我们在 4 名患者(4/24,16.7%)中发现了 6 个序列变化,其中 4 个被确认为致癌突变。在 KRAS 基因中,我们在 4 名患者中检测到了序列变化(4/24,16.7%)。相反,我们在 EGFR 或 TP53 基因中均未发现致病性或潜在致病性的序列变化。我们的结果表明,序列变化既不是特定于某一组织学亚型、临床阶段或淋巴结受累,也不是 HPV(人乳头瘤病毒)感染的结果,而是从早期临床阶段开始独立出现的。我们观察到 DNA 序列变化与 hTERC 基因扩增之间存在相关性,但我们没有发现使用阵列 CGH(基于阵列的比较基因组杂交)技术检测到的 DNA 序列变化与检测到的拷贝数改变之间存在显著关系。尽管我们的结果证实了 PIK3CA 和 KRAS 基因中的致癌突变在宫颈癌发病机制中的肿瘤转化过程中起着重要作用,但它们在早期临床阶段的鉴定应鼓励进一步研究,以更好地了解这些突变,并利用它们进行更详细的诊断。