Nucleotide polymorphisms of the human papillomavirus 16 E1 gene

The E1 ORF is one of the most conserved regions in the human papillomavirus (HPV) genome. The complete E1 gene of the HPV16 genome was amplified with four overlapping primer sets in 16 high-grade (CIN II, III) and 13 low-grade cervical (CIN I) intraepithelial neoplasias as well as in one cervical cancer case. Sequence analysis of the E6 and E7 genes was also carried out in the same cervical samples in order to confirm the association between nucleotide sequence variations in the HPV16 E1 ORF and HPV16 variant lineages. Analysis of the E1 ORF revealed 27 nucleotide changes, and these changes were correlated with those found in HPV16 Asian American and African type II variants. Of these nucleotide variations, A1668G, G2073A, T2169C, T2189C, A2453T, C2454T, A2587T and G2650A were identified only in high-grade dysplasia cases. A phylogenetic tree of the E1 ORF and nucleotide sequence analysis of the E1, E6 and E7 genes revealed that intratypic nucleotide sequence polymorphisms located in the E1 ORF can be used to identify the major phylogenetic branch to which a HPV16 genome belongs. Moreover, amplification of the E1 ORF revealed a disruption between nucleotides 878 and 1523 in five high- and two low-grade cervical cases, indicating that integration of HPV DNA occurs at an early stage of viral infection.     

Biologic characteristics of specific human papillomavirus types predicted from morphology of cervical lesions.

Human papillomavirus (HPV) DNA was detected by Southern blot hybridization in cervicovaginal lavage samples from 199 of 329 (60.5%) women attending a municipal hospital colposcopy clinic. Human papillomavirus was identified in 195 of 264 (73.9%) patients with a squamous intraepithelial lesion or cancer on biopsy or Papanicolaou smear (Bethesda system) compared with 11 of 65 (16.9%) without squamous intraepithelial lesion (P < .0001). The most common HPV type identified was HPV 16 (20.6% of positive samples), and 36.7% of isolates contained uncharacterized HPVs. Of women with cervical intraepithelial neoplasia (CIN) grade III or cancer, 23.4% were infected with HPV 16 compared with less than 4% with any other single HPV type. Based on biopsy diagnosis in patients infected with specific HPV types, HPVs 6 and 11 had low oncogenic potential; HPVs 18, 31, 35, and 45 had intermediate oncogenic potential; and HPVs 16 and 33 had high oncogenic potential. Hyperchromatic, unusually enlarged nuclei ("meganuclei"), and/or abnormal mitoses were found significantly more often in lesions infected with HPVs 16, 33, and 35 than in those infected with HPVs 6, 11, 18, 31, and 45, even in low-grade lesions, and may represent a histologic marker for HPVs with significant oncogenic potential. Human papillomavirus capsid protein was detected significantly less often by immunocytochemical staining in CIN I and CIN II lesions infected with HPVs 16 and 33 (8.3%) than in those infected with HPVs 6, 11, 18, and 31 (60%; P = .007), suggesting early abnormalities in cellular differentiation in lesions infected with highly oncogenic HPVs.     

Human papillomavirus type 58 DNA sequence.

The complete nucleotide sequence of human papillomavirus type 58 (HPV 58) DNA cloned from an invasive cervical carcinoma was determined. The HPV 58 genome consists of 7824 nucleotides, containing 37.9% of GC residues, and has a similar genome organization of other HPVs. On the nucleotide sequence level, it conserves the signal sequences for regulation of gene expression as with other genital HPVs and exhibits an extensive homology with HPV 33 (77%). Comparative analysis of amino acid sequences reveals that HPV 58 is closely related with HPVs 16, 31, and 33, and is more distantly related with HPVs 6, 11, 18, and 39. HPVs 58, 16, 31, and 33 can be regarded as a group in HPV.     

人乳头瘤病毒16型转换基因的序列分析

为了解中国地区宫颈癌病人中人乳头瘤病毒１６型Ｅ６Ｅ７基因结构特点,从中国山东地区宫颈癌活检组织中提取组织ＤＮＡ,经ＨＰＶ多重引物ＰＣＲ法鉴定标本中感染ＨＰＶ型别,选单纯感染ＨＰＶ１６两例标本ＤＮＡ为模板进行ＰＣＲ扩增,获得ＨＰＶ１６Ｅ６Ｅ７基因后,重组入ｐＡＬＴＥＲ－１载体,进行双向测序、分析。ＤＮＡ序列分析表明：两例标本的ＨＰＶ１６Ｅ６Ｅ７序列全长均为７７６ｂｐ,与已发表的德国标准株长度相等,两     

DNA-EIA to detect high and low risk HPV genotypes in cervical lesions with E6/E7 primer mediated multiplex PCR.

BACKGROUND: Oncogenicity of human papillomavirus (HPV) DNA in premalignant and malignant uterine cervical diseases is mainly induced by E6/E7 open reading frame (ORF). The presence of an oncogenic HPV DNA may be a diagnostic marker for the detection of cytologically negative smears. AIMS: To evaluate an original polymerase chain reaction enzyme immunoassay (PCR-EIA) for the detection and typing of oncogenic and non-oncogenic HPV types. METHODS: The test was an original multiplex labelled PCR-EIA for the detection and typing of oncogenic and non-oncogenic HPV using three consensus sequence primers within the oncogenic E6/E7 ORF. One primer was dinitrophenyl (DNP) labelled and the DNP labelled amplimers could be further hybridised with specific biotinylated oligoprobes mixed in only two cocktails: oncogenic (16, 18, 31, 33, 35, 52, and 58) and non-oncogenic (6 and 11) HPV types in only two wells; then biotinylated oligoprobes were deposited in streptavidin-coated microplates. The PCR-EIA was validated on HPV plasmids (types 6, 11, 16, 18, 31, 35, 52, and 58) and used to evaluate cervical scrapes from 181 patients (median age 32 years) at high risk for cervical cancer. RESULTS: HPV were detected in the cervical scrapes of 88 of 181 patients (48.6%); nine with non-oncogenic HPV (5.0%) and 79 with oncogenic HPV (43.6%) including 29 coinfections with oncogenic and non-oncogenic HPV. The number of oncogenic HPV infections increased with the presence of high grade lesions: 95.8% of the cervical scrapes from patients with high grade lesions contained oncogenic HPV compared with 32.1% of the specimens from patients without any lesions detectable by colposcopy and/or by cytological examination of the cervical smears. Moreover, 60% of cervical scrapes exhibiting low grade lesions contained oncogenic HPV. CONCLUSIONS: This test is simple, specific, sensitive, safe, fast, reproducible, and easy to use in routine practice. Thus, it is possible to detect simultaneously on a simple cervical scrape, two kinds of HPV--oncogenic and non-oncogenic--in just two microplate wells with non-isotopic oligoprobes.     

DNA sequence of the HPV-16 E5 ORF and the structural conservation of its encoded protein

Infection of cervical epithelium by human papillomavirus type 16 (HPV-16) appears to be closely associated with the development of cervical dysplasia and carcinoma. By inference from genetic and biochemical studies of the bovine papillomavirus, the E5 ORF of the human papillomaviruses is anticipated to encode a "transforming" protein. In an effort to compare the E5 ORF of HPV-16 with other human papillomaviruses and bovine papillomavirus, we sequenced this region from a new isolate of HPV-16 which was derived from extrachromosomal viral DNA within a premalignant cervical lesion (cervical intraepithelial neoplasia, grade III, or CIN III). In addition, we also sequenced the original isolate of HPV-16 (derived from integrated viral DNA by Durst et al. [Proc. Natl. Acad. Sci. USA 80, 3812-3815 (1983)] and sequenced by Seedorf et al. [Virology 145, 181-185 (1985)]. Both HPV-16 isolates contained an additional nucleotide (T) at bp 3906. This nucleotide addition caused a frameshift in the E5 ORF such that it now contains an initiation codon at bp 3849; the frameshift also alters the predicted E5 NH2 terminus but retains the original COOH half of the protein. E5 proteins encoded by several HPVs which infect the genital region (e.g., types 6, 11, 16, 18, 33) exhibit a conserved trimodal hydrophobic structure, but not a conserved amino acid sequence.     

The E7 functions of human papillomaviruses in rat 3Y1 cells.

Among more than 60 human papillomavirus (HPV) genotypes, several HPVs are believed to be high risk because they are found in close association with cervical carcinoma. We compared the E7 genes from HPVs 1, 6b, 16, 18, and 33 for their transactivating, transforming, and mitogenic functions in a single cell line rat 3Y1. Whereas both the low-risk (1 and 6b) and the high-risk (16, 18, and 33) HPVs were transactivating for the adenovirus E2 promoter, only the high-risk HPVs were capable of focal transformation as assayed by an efficient method using the SR alpha-promoter and in conjunction with the HPV 16 E6 gene. The putative oncogenicity of HPVs appears to be reflected in vitro by the focal transformation, but not by the transactivation. Transient expression of the E7 genes controlled by the dexamethasone-responsive MMTV-LTR showed that the HPV 16 mutant E7s only with residual transforming activity were not mitogenic, but that, although the low-risk HPV E7s were less efficient, both the low-risk and high-risk HPV E7s were capable of inducing cellular DNA synthesis. Probably, the capability to induce cell DNA synthesis is necessary but not sufficient for the E7-mediated focal transformation.     

Functional dissociation of transforming genes of human papillomavirus type 16

Human papillomavirus (HPV) type 16 is thought to be responsible for development of cervical carcinomas, but the mechanism of its carcinogenic action is unknown. To determine which viral genes are involved in cellular transformation, we constructed recombinant murine retrovirus DNAs containing various subgenomic fragments of the HPV 16 early region and examined their transforming activities. The results show that the E6 and E7 ORFs are the transforming genes of HPV 16; the former governs the tumorigenicity in nude mice and the latter influences cell growth properties such as saturation density and colony formation in soft agar. There may also be a tumor-suppressing gene in the E1-E2 ORF region, because the tumorigenic activity of recombinant DNA containing the E1 ORF and the 5' portion of the E2 ORF in addition to the E6 and E7 ORFs was much lower than that of recombinant DNA containing only the E6 and E7 ORFs.     

The phylogenetic relationship and complete nucleotide sequence of human papillomavirus type 35.

The 7851-bp nucleotide sequence of human papillomavirus (HPV) type 35 was determined. HPV 35 is associated with high-grade cervical intraepithelial neoplasia and invasive carcinomas. From the HPV 35 sequence, open reading frames encoding putative proteins E6, E7, E1, E2, E4, E5, L2, and L1, common to other mucosal HPV types, were identified. Structural and control elements present in the long control region (LCR) conserved among other mucosal HPV types were also present in HPV 35. Analysis of the LCR revealed an additional 20-bp sequence element present in all HPV types associated with malignant proliferation. To further classify HPV 35 with regard to oncogenic potential, phylogenetic analysis of the E6 and E7 proteins from the anogenital HPV types 6, 11, 16, 18, 31, 33, 35, 39, 43, 44, 45, and 51 was performed. This analysis indicated three distinct HPV subgroups; those associated with benign lesions and two branches of those HPV types more often associated with malignant proliferation. HPV 35 is most closely related to HPV types 31 and 16.     

Oligonucleotide primers for DNA amplification of the early regions 1, 6, and 7 from human papillomavirus types 6, 11, 16, 18, 31, and 33

Summary Human papillomavirus (HPV) type-specific sequences required for polymerase chain reaction (PCR) mediated amplification of HPV DNA sequences are presented. One primer pair within the E1 open reading frame (ORF) was shared by HPV 6, HPV 11, HPV 16, and HPV 31, whereas the other primer pair within the E1 ORF was specific for HPV 16. Eight primer pairs from the E6 and E7 ORFs specifically detected HPV 6, HPV 16, HPV 18, and HPV 33 sequences. This system has been used for detection of HPV DNA in biopsies, cytological smears and sections of formalin-fixed tissues.     

Identification of multiple genital HPV types and sequence variants by consensus and nested type-specific PCR coupled with cycle sequencing

Consensus and type-specific HPV primers were employed for PCR and cycle sequencing of genital HPVs in scrapings and colposcopically directed biopsies of the cervix from a cohort of 188 female sex workers. A total of 27 individuals tested positive for a broad spectrum of HPV types, including HPVs 6b, 16, 18, 31, 33, 34, 35, 45, 56 and 58, as well as a new HPV type, with seven individuals displaying dual infections. Good correlation between the results of individually paired samples was observed. A HPV 16 primer biotinylated at the 5' end was also used as a probe, which could successfully detect amplified products of HPV 16 but not other HPV types tested by an automated ELISA detection system. DNA sequence analysis revealed several HPV sequence variants that harbored mutations, especially in the E6 gene, many of which culminated in non-conservative amino acid substitutions in the transforming E6 oncoprotein. Such an approach of coupling PCR with cycle sequencing permits the determination of many known and even novel HPV types associated with varying degrees of risk to cervical carcinogenesis, and enables the identification of HPV sequence variants of putative biological and clinical significance, thus justifying its utility as an adjunct tool to complement cervical cytology and colposcopy. This study also emphasises the need for educational, interventional and behavioral modification to minimise HPV transmission, such as through consistent condom usage among sex workers.     

"Low-risk" and "high-risk" HPV-infection and K-ras gene point mutations in human cervical cancer: a study of 31 cases

To analyze the coexistence of human papilloma virus (HPV) infection and K-ras gene activation in cervical neoplasia, we investigated 31 (seven pre-invasive and 24 invasive) cervical carcinomas for "low-risk" (types 6 and 11) and "high-risk" (types 16 and 18) HPVs and K-ras point mutations using PCR-based technology. "Low-risk" HPVs were not detected in the group investigated; however, 20 of 31 (64%) cases were HPV 16 positive, while HPV 18 was found in only three (9.7%) samples (HPV 6/11 v. HPV 16/18, p < 0.0001; HPV 16 v. HPV 18, p < 0.0001; Fisher's exact test). There was a K-ras codon 12 point mutation in two of 31 (6.4%) neoplasms, with none of the cases showing a K-ras codon 13 point mutation. Two moderately differentiated squamous carcinomas showed K-ras exon 2 gene alterations. Interestingly, none of the pre-invasive cervical carcinomas displayed K-ras gene point mutations. The mean patient age did not differ significantly in the number of HPV-positive and -negative cases. A coexistence of "high-risk" human papillomavirus DNA with K-ras gene alterations was observed in three of 31 (9.7%) neoplasms (one IIA and two IB moderately differentiated cervical carcinomas). Our results suggest that "high-risk" HPVs coexist with K-ras gene alterations in a subset of moderately differentiated carcinomas of the cervix uteri.     

人乳头瘤病毒E6、E7的表达对足叶乙甙作用下细胞凋亡的影响

目的探讨人乳头瘤毒(HPV)16早期基因E6和E7的表达对NIKS细胞凋亡表型的影响。方法用含有HPV16的E6、HPV16E7、HPV16E6E7病毒癌基因的逆转录病毒感染角质生成细胞株NIKS,puromycin筛选稳定表达细胞;基因组PCR和Western blot方法验证E6和E7的表达;转染后的NIKS细胞用不同浓度的足叶乙甙处理,流式细胞仪和Annexin V染色检测细胞凋亡情况。结果经逆转录病毒感染后,建立表达E6、E7及E6E7的NIKS细胞株,基因组PCR证明E6和E7整合入NIKS细胞基因组;Western blot证实表达的E6、E7具有生物学活性,能够分别降解p53和pRB;在足叶乙甙处理后,E6、E7以及E6E7表达细胞发生明显的细胞死亡,E6和E7具有叠加作用,且具有剂量依赖性,Annexin V染色证实细胞发生凋亡,凋亡率分别为(33.5±3.2)%、(38.3±2.4)%和(56.7±4.3)%。结论人乳头瘤病毒E6和E7的表达都可以促进细胞对DNA损伤药物的敏感性,提示乳头瘤病毒感染状态有可能影响肿瘤细胞对化疗的敏感性。     

The presence of human papillomavirus 16 in neural structures and vascular endothelial cells

Human papillomavirus (HPV) is known as a strictly epitheliotropic pathogen. Our results raised the possibility that HPV 16 is present in neural cells and in the vascular endothelium. By in situ hybridization, we have detected HPV 16 E6 ORF sequence in small blood vessels and peripheral nerves adjacent to oral and cervical cancers. The same structures have clearly shown immunohistochemical reactivity for the E6 oncoprotein. These results were verified by PCR applied to E6 and L1 ORFs following microscopic laser dissection of the immunohistochemically positive nerves and vessels. These observations suggest that HPV 16 DNA and protein are present in neurons and endothelial cells in the vicinity of HPV-associated tumors. The HPV 16 genome presumably exists in a non-replicating form in the neurons and constitutively produces high levels of E6 and E7 proteins with an unknown neuropathological outcome.     

Molecular mechanisms of cervical carcinogenesis by high‐risk human papillomaviruses: novel functions of E6 and E7 oncoproteins

Over the last two decades, since the initial discovery of human papillomavirus (HPV) type 16 and 18 DNAs in cervical cancers by Dr. Harald zur Hausen (winner of the Nobel Prize in Physiology or Medicine, 2008), the HPVs have been well characterised as causative agents for cervical cancer. Viral DNA from a specific group of HPVs can be detected in at least 90% of all cervical cancers and two viral genes, E6 and E7, are invariably expressed in HPV‐positive cervical cancer cells. Their gene products are known to inactivate the major tumour suppressors, p53 and retinoblastoma protein (pRB), respectively. In addition, one function of E6 is to activate telomerase, and E6 and E7 cooperate to effectively immortalise human primary epithelial cells. Though expression of E6 and E7 is itself not sufficient for cancer development, it seems to be either directly or indirectly involved in every stage of multi‐step carcinogenesis. Epidemiological and biological studies suggest the potential efficacy of prophylactic vaccines to prevent genital HPV infection as an anti‐cancer strategy. However, given the widespread nature of HPV infection and unresolved issues about the duration and type specificity of the currently available HPV vaccines, it is crucial that molecular details of the natural history of HPV infection as well as the biological activities of the viral oncoproteins be elucidated in order to provide the basis for development of new therapeutic strategies against HPV‐associated malignancies. This review highlights novel functions of E6 and E7 as well as the molecular mechanisms of HPV‐induced carcinogenesis. Copyright © 2009 John Wiley & Sons, Ltd.