Doctoral Program in Obstetrics and Gynecology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
Department of Obstetrics and Gynecology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
PLoS One. 2018 Feb 21;13(2):e0193061. doi: 10.1371/journal.pone.0193061. eCollection 2018.
A few studies previously suggested that human papillomavirus (HPV) E6 messenger RNA (mRNA) may exist uniformly in all grades of cervical intraepithelial neoplasia (CIN), whereas the detection rate of E7 mRNA may increase with disease progression from low-grade CIN to invasive carcinoma. The aim of this study was to clarify the different roles of E6 and E7 mRNAs in cervical carcinogenesis. The presence of each E6 and E7 mRNA was analyzed in 171 patients with pathologically-diagnosed CIN or cervical carcinoma. We utilized a RT-PCR assay based on consensus primers which could detect E6 mRNA (full-length E6/E7 transcript) and E7 mRNAs (spliced E6*/E7 transcripts) separately for various HPV types. E7 mRNAs were detected in 6% of CIN1, 12% of CIN2, 24% of CIN3, and 54% of cervical carcinoma. The presence of E7 mRNAs was significantly associated with progression from low-grade CIN to invasive carcinoma in contrast with E6 mRNA or high-risk HPV (HR-HPV) DNA (p = 0.00011, 0.80 and 0.54). The presence of both E6 and E7 mRNAs was significantly associated with HPV16/18 DNA but not with HR-HPV DNA (p = 0.0079 and 0.21), while the presence of E6 mRNA was significantly associated with HR-HPV DNA but not with HPV16/18 DNA (p = 0.036 and 0.089). The presence of both E6 and E7 mRNAs showed high specificity and low sensitivity (100% and 19%) for detecting CIN2+ by contrast with the positivity for HR-HPV DNA showing low specificity and high sensitivity (19% and 89%). The positive predictive value for detecting CIN2+ was even higher by the presence of both E6 and E7 mRNAs than by the positivity for HR-HPV DNA (100% vs. 91%). In 31 patients followed up for CIN1-2, the presence of both E6 and E7 mRNAs showed significant association with the occurrence of upgraded abnormal cytology in contrast with E6 mRNA, HR-HPV DNA, or HPV16/18 DNA (p = 0.034, 0.73, 0.53, and 0.72). Our findings support previous studies according to which E7 mRNA is more closely involved in cervical carcinogenesis than E6 mRNA. Moreover, the separate analysis of E6 and E7 mRNAs may be more useful than HR-HPV DNA test for detecting CIN2+ precisely and predicting disease progression. Further accumulation of evidence is warranted to validate our findings.
一些研究先前表明，人乳头瘤病毒（HPV）E6 信使 RNA（mRNA）可能均匀存在于所有级别的宫颈上皮内瘤变（CIN）中，而 E7 mRNA 的检测率可能随着疾病从低级别 CIN 进展为浸润性癌而增加。本研究旨在阐明 E6 和 E7 mRNAs 在宫颈癌发生中的不同作用。分析了 171 例经病理诊断为 CIN 或宫颈癌的患者的每个 E6 和 E7 mRNA 的存在情况。我们利用基于共识引物的 RT-PCR 检测了各种 HPV 类型的 E6 mRNA（全长 E6/E7 转录本）和 E7 mRNAs（拼接的 E6*/E7 转录本）。在 CIN1 中检测到 6%的 E7 mRNAs，在 CIN2 中检测到 12%的 E7 mRNAs，在 CIN3 中检测到 24%的 E7 mRNAs，在宫颈癌中检测到 54%的 E7 mRNAs。E7 mRNAs 的存在与从低级别 CIN 进展为浸润性癌显著相关，而与 E6 mRNA 或高危型 HPV（HR-HPV）DNA 无关（p=0.00011，0.80 和 0.54）。E6 和 E7 mRNAs 的存在均与 HPV16/18 DNA 显著相关，但与 HR-HPV DNA 无关（p=0.0079 和 0.21），而 E6 mRNA 的存在与 HR-HPV DNA 显著相关，但与 HPV16/18 DNA 无关（p=0.036 和 0.089）。E6 和 E7 mRNAs 的存在对检测 CIN2+具有很高的特异性和低敏感性（100%和 19%），而 HR-HPV DNA 的阳性率特异性低而敏感性高（19%和 89%）。与 HR-HPV DNA 的阳性率相比，E6 和 E7 mRNAs 的存在对检测 CIN2+的阳性预测值更高（100%比 91%）。在 31 例随访 CIN1-2 的患者中，E6 和 E7 mRNAs 的存在与异常细胞学升级的发生显著相关，而与 E6 mRNA、HR-HPV DNA 或 HPV16/18 DNA 无关（p=0.034、0.73、0.53 和 0.72）。我们的研究结果支持先前的研究，即 E7 mRNA 比 E6 mRNA 更密切地参与宫颈癌的发生。此外，E6 和 E7 mRNAs 的单独分析可能比 HR-HPV DNA 检测更有助于精确检测 CIN2+并预测疾病进展。需要进一步积累证据来验证我们的发现。
