High level HPV-16 E7 oncoprotein expression correlates with reduced pRb-levels in cervical biopsies (original) (raw)
Related papers
International Journal of Medical Students
The human papillomavirus (HPV) was the first virus known to induce carcinogenesis and is associated with cancers of the uterine cervix, anogenital tumors and malignancies of the head and neck. This paper reviews the structure and basic genomic characteristics of the virus and outlines the clinical involvement of the main HPV serotypes, focusing on the carcinogenic role of HPV-16 and 18. The mechanisms that occur in the development of cervical neoplasia due to the oncogenic proteins E6 and E7 which interfere with the regulation of the cell cycle through their interaction with p53 and retinoblastoma protein are described. Epidemiological factors, diagnostic tools and the management of the disease are also reviewed, along with the available vaccines to prevent the viral infection. Insights on current research on involvement of oxidative stress and micro-RNAs in cervical carcinogenesis are also explored as they may unlock new means of diagnosis and treatment in the future.
Cellular and Viral Markers in Human Papillomavirus Related Cervical Lesions Progression
The etiological role of high-risk human papillomavirus (HPV) in invasive cervical cancer has been demonstrated by epidemiological and molecular studies. In HPV-associated cervical carcinomas, the expression/ function of p16 is impaired by the action of viral E6 and E7 oncoproteins. In order to evaluate the potential of p16INK4a and E4 HPV16 mRNA as clinical markers for progression and development of cervical malignant lesions we analyzed cervical specimens from patients with different cytology (collected in liquid cytology medium from 89 women, (22-72 years old) which were used to isolate genomic DNA (High Pure PCR Template, Roche Diagnostics) and RNA (RNAeasy kit-Qiagen). E4 HPV16 mRNA gene expression was performed using E4 HPV16 PCR and the results obtained were confirmed by Southern Blot Hybridization. We evaluated p16INK4a expression using TaqMan Real Time PCR (Applied Biosystems). The molecular detection of HPV DNA and E4 HPV16 expression were corroborated with p16INK4a express...
Virology, 2007
Epidemiological studies have demonstrated that 15 different mucosal human papillomavirus (HPV) types of the genus alpha of the HPV phylogetic tree are classified as high risk for cervical cancer development. Three additional HPV types of the same genus, HPV26, 53 and 66, are classified as probable high-risk types. In this study, we have characterized the biological properties of the E7 oncoproteins from these three HPV types. All of the corresponding E7 proteins were able to associate with retinoblastoma protein (pRb) and up-regulated the expression of several positive cell cycle regulators, i.e. CDK2, cyclin A and cylin E. However, HPV26 E7 appears to be more efficient than HPV53 and 66 E7 in upregulating the transcription of cyclin A. Unlike E7 from the high-risk type HPV16 protein, HPV26, 53 and 66 did not efficiently promote pRb degradation. In addition, E7 from these viruses was able to promote proliferation of primary human keratinocytes and circumvent G1 arrest imposed by overexpression of p16 INK4a , but with less efficiency than the high-risk HPV16 E7. Together, our data show that in vitro properties of these E7 proteins correlate with the epidemiological classification of HPV26, 53 and 66 as HPV types with an intermediate risk for cervical cancer development.
HPV-16 E2 Physical Status and Molecular Evolution in Vivo in Cervical Carcinomas
The International Journal of Biological Markers, 2013
A key event in the development of cervical carcinoma is the deregulated expression of high-risk human papillomavirus (HR-HPV) oncogenes, most commonly due to HPV integration into host DNA. Here we explored whether HPV-16 E2 gene integrity is a biomarker of progressive disease with oncogenes expression. HPV-16 genome disruption was assessed by amplification of the entire E2 gene, while mRNA expression patterns of the E1, E2, E6, and E7 genes were evaluated by reverse transcription PCR (RT-PCR). As expected, E2 disruption was significantly higher among patients with cervical cancers than subjects with benign lesions (p=0.02). The status of the E2 gene correlated with tumorogenesis, and seemed also to correlate with the stage of the carcinomas, since integrated HPV-16 DNA was frequently detected in patients with advanced cancer stages (75% of stage III vs 60% stages I and II). In bivariate analysis, the lesions’ grade was most significantly associated with HPV-16 DNA disruption (p<0...
The human papillomavirus (HPV) was the first virus known to induce carcinogenesis and is associated with cancers of the uterine cervix, anogenital tumors and malignancies of the head and neck. This paper reviews the structure and basic genomic characteristics of the virus and outlines the clinical involvement of the main HPV serotypes, focusing on the carcinogenic role of HPV-16 and 18. The mechanisms that occur in the development of cervical neoplasia due to the oncogenic proteins E6 and E7 which interfere with the regulation of the cell cycle through their interaction with p53 and retinoblastoma protein are described. Epidemiological factors, diagnostic tools and the management of the disease are also reviewed, along with the available vaccines to prevent the viral infection. Insights on current research on involvement of oxidative stress and micro-RNAs in cervical carcinogenesis are also explored as they may unlock new means of diagnosis and treatment in the future.
Journal of General Virology, 2005
E7 proteins are major oncoproteins of high-risk human papillomaviruses (HPVs), which play a key role in cervical carcinogenesis. These proteins have been shown to immortalize primary human cells. Due to the absence of antibodies with suitable sensitivity and specificity, little is known about expression of the E7 oncoproteins in naturally infected tissues. Recently, high-level expression of the E7 protein of HPV-16, the most prevalent oncogenic HPV type, was demonstrated in cervical carcinomas by immunohistochemistry; however, approximately 15 additional high-risk HPV types are known to be associated with cervical carcinoma. It is unknown whether the E7 oncoproteins of HPV-18 and-45, the second and third most prevalent HPV types, are expressed in cervical cancers. Using antibodies against HPV-18 and-45 E7 proteins, it is shown here for the first time that the HPV-18 and-45 E7 proteins can be detected in cervical carcinoma biopsies. Together with anti-HPV-16 E7 antibodies, this could create the possibility of detecting E7 oncoproteins in approximately 80 % of all cervical cancers.
Journal of Clinical Virology, 2001
Background: Integration of human papilloma virus (HPV) 16 DNA is considered an important genetic change in cervical lesion progression towards ICC. The viral E2 gene is often disrupted by this process, releasing suppression of viral E6/E7 oncogenes, a key factor for oncogenic progression. Objecti6es: To evaluate the physical status of HPV 16 E2 gene in cervical preneoplastic and neoplastic lesions and its relation with lesion severity. Study design: A sensitive PCR approach for the detection of an intact E2 HPV 16 gene in infected epithelial cells from the cervix with low grade squamous intraepithelial lesion (LGSIL), high grade squamous intraepithelial lesion (HGSIL) and invasive cervical carcinoma (ICC) diagnosis was applied. The correlation between gene disruption and lesion stage was examined. Results: Sixty-two LGSIL, 39 HGSIL and 24 ICC samples were analyzed. Fifty-seven LGSIL [92%], 13 HGSIL [33%] and 4 ICC [17%] showed results compatible with an intact E2 gene, while 5 LGSIL [8%], 26 HGSIL [67%] and 20 ICC [83%] samples gave no signal. Conclusions: HPV 16 E2 gene disruption showed a positive correlation with cervical lesion progression, particularly from LGSIL to HGSIL. Although additional genetic events are very likely to be needed for HGSIL to ICC progression, the E2 gene disruption is a putative early marker to consider in the prognostic analysis of HPV 16 chronically infected women.