Institute of Veterinary Genetics-National Council of Scientific and Technical Investigations, National University of La Plata, 60 and 118 street, La Plata, Buenos Aires, Argentina.
Pathol Oncol Res. 2010 Sep;16(3):461-8. doi: 10.1007/s12253-010-9246-x. Epub 2010 Mar 17.
The aim of the present study is to determine the presence and molecular integrity of high-risk HPV types in colorectal adenocarcinomas and to assess whether viral DNA is related to common proto-oncogene alterations, such as k-ras mutations and c-myc gene amplification, in colorectal cancer. Seventy-five colorectal adenocarcinomas were screened for HPV infection using nested-PCR (MY09/11-GP5+/6+). HPV typing was performed by type-specific PCR for HPV 16 and HPV 18 DNA. Unidentified samples were subsequently sequenced to determine the viral genotype. The physical status of HPV was determined by a nested PCR approach for type-specific E2 sequences. C-myc amplification was assessed by co-amplification with β-globin as control locus, and mutation in k-ras codons 12 and 13 by ARMS-PCR. Overall, HPV was detected in thirty-three colorectal specimens (44%). HPV 16 was the prevalent type (16/75), followed by HPV 18 (15/75), HPV 31 (1/75) and HPV 66 (1/75). E2 disruption was detected in 56.3% of HPV 16 and in 40% of HPV 18 positive tumors. C-myc amplification was detected in 29.4% of cases, while k-ras mutations in 30.7%. There was no significant trend for HPV infection in tumors harboring either k-ras or c-myc alterations. This study demonstrates HPV DNA and viral integration in colorectal tumors, suggesting a potential role of this virus in colorectal carcinogenesis. There was no concurrence, however, of k-ras and c-myc activation with viral infection.
本研究旨在确定结直肠腺癌中高危 HPV 型的存在和分子完整性，并评估病毒 DNA 是否与结直肠癌中常见原癌基因改变（如 k-ras 突变和 c-myc 基因扩增）相关。使用巢式 PCR（MY09/11-GP5+/6+）对 75 例结直肠腺癌进行 HPV 感染筛查。使用 HPV 16 和 HPV 18 DNA 的型特异性 PCR 进行 HPV 分型。随后对未识别的样本进行测序以确定病毒基因型。通过针对 HPV 特异性 E2 序列的巢式 PCR 方法确定 HPV 的物理状态。通过与β-球蛋白共同扩增作为对照基因座来评估 c-myc 扩增，并通过 ARMS-PCR 检测 k-ras 密码子 12 和 13 的突变。总体而言，在 33 例结直肠标本中检测到 HPV（44%）。HPV 16 是最常见的类型（16/75），其次是 HPV 18（15/75）、HPV 31（1/75）和 HPV 66（1/75）。在 56.3%的 HPV 16 阳性肿瘤和 40%的 HPV 18 阳性肿瘤中检测到 E2 破坏。在 29.4%的病例中检测到 c-myc 扩增，而在 30.7%的病例中检测到 k-ras 突变。在携带 k-ras 或 c-myc 改变的肿瘤中，HPV 感染没有明显的趋势。本研究表明 HPV DNA 和病毒整合存在于结直肠肿瘤中，提示该病毒在结直肠癌发生中的潜在作用。然而，k-ras 和 c-myc 的激活与病毒感染没有一致性。
