Characterization of sequence variations within HPV16 isolates among Indian women: prediction of causal role of rare non-synonymous variations within intact isolates in cervical cancer pathogenesis

We re-sequenced HPV16 genome (~6 kb) implicated in cervical carcinogenesis (LCR, E2, E5, E6, E7, L1, L2) to prioritize sequence variants for functional validation as biomarkers, using CaCx cases (n=74) and asymptomatic controls (n=24). Of the nucleotide variations recorded (n=271), non-synonymous changes in L2 region were significantly higher (p=0.005) among cases (2.67%) compared to controls (1.27%). Using SIFT database, 29 non-synonymous changes (frequency=0.01-0.03) predicted as deleterious to protein functions were identified. Haplotype analysis considering 110 polymorphic variations (frequency> or =0.05) within intact viral isolates (53 CaCx cases and 21 controls) using NETWORK software, confirmed Asian-American (AA, 14.86%) and European (E, 85.14%) variants, differing at 78 positions. The E-variants portrayed thirty-six haplotypes, of which, E-12 was most prevalent within cases (38.1%; 16/42) and controls (28.57%; 6/21) harboring polymorphic variations at 10 positions, in contrast to HPV16R. Cases of the E-12 haplotype harbored 7 deleterious mutations distributed within L1 (n=1), E2 (n=1), E5 (n=1), and L2 (n=4), while none within similar controls. Thus rare deleterious variations within genes implicated in productive infection over the E-12 haplotype background of intact HPV16 isolates might be of causal relevance for CaCx development.     

Increased detection of HPV 16 virus in invasive, but not in early cervical cancers.

Human papilloma virus type 16 (HPV 16) DNA is found in about 50% of cervical squamous cell carcinomas (SCCs), and this association has raised the possibility of a causal role for HPV 16 in cervical carcinogenesis. We have tested this hypothesis by assaying a series of biopsies (n = 119) ranging from normal mucosa to infiltrating SCC with the PCR-technique for the presence of HPV 16 DNA. While HPV 16 DNA was detected in 50% of our cases with invasive SCC, the incidence of HPV 16-positive samples was about 10% in all other biopsies ranging from normal mucosa to cases of carcinoma in situ. HPV 16 therefore appears to be involved in late tumor promotion but not in early tumor development.     

子宫颈癌中Hedgehog信号通路蛋白表达与人乳头状瘤病毒16型感染的关系

目的 探讨Hedgehog(Hh)信号通路蛋白在宫颈癌及其癌前病变中的临床病理学意义,并分析其与人乳头状瘤病毒(HPV)16型感染的关系.方法 32例正常宫颈上皮、71例宫颈上皮内瘤变(CIN;CIN Ⅰ 28例,CIN Ⅱ 18例,CIN Ⅲ25例)和80例宫颈鳞状细胞癌共183例选自延边大学医院、延边妇幼保健院和延边肿瘤医院病理科存档蜡块.应用PCR技术检测上述组织中HPV16型的感染情况,并应用Shh、Ihh、Ptch和Smo 4种Hh信号通路蛋白抗体、组织芯片和免疫组织化学EnVision法检测Hh信号通路蛋白在上述病变组织中的表达情况.结果 Shh、Ihh、Ptch和Smo在正常宫颈黏膜上皮中为弱阳性,而在宫颈癌和CIN Ⅲ中呈强阳性,其表达率均显著高于正常宫颈黏膜上皮(P均<0.05).80例官颈癌标本中HPV16阳性率是77.5%(62/80),而且Shh蛋白的强阳性率在HPV16型阳性的宫颈癌组织中显著高于HPV16阴性组(P<0.05).结论 Hh信号通路蛋白过表达可以作为宫颈癌及其癌前病变的早期辅助诊断指标并有望成为宫颈癌靶向治疗的新靶点,而且Shh蛋白的过表达与HPV16型感染密切相关.     

染色体外游离态的子宫颈癌HPV16分离株E1／E2区的基因 …

目的 观察子宫颈癌组织中呈染色体外质粒状态的ＨＰＶ１６分离株Ｅ１／Ｅ２基因序列。方法 Ｓｏｕｔｈｅｒｎ转印杂交检测癌组织中ＨＰＶ１６基因组的物理状态。对８例游离状态的ＨＰＶ１６分离株Ｅ１／Ｅ２区进行ＰＣＲ扩增,克隆后酶切分析和ＤＮＡ序列分析。结果 对２８例ＨＰＶ１６阳性子宫颈癌中病毒ＤＮＡ杂效结果显示８例呈染色体外质粒方式存在。ＰＣＲ克隆鉴定发现８例分离株都具有完整的Ｅ１／Ｅ２区域。此外４例分离株     

中国地方株人乳头瘤病毒16型E7基因一级结构及其变异

从湖北地区一宫颈癌活检组织中提取ＤＮＡ，采取加端聚合链反应（Ａｄｄ－ｏｎ ＰＣＲ）技术，获得了人乳头瘤病毒１６型E７基因（ＨＰＶＩ６Ｅ７）。将该基因克隆于载体ｐＵＣ１８后，进行了该基因一级结构顺序分析。完整的ＨＰＶ１６Ｅ７湖北株基因（ＨＰＶ１６Ｅ７－ＨＢ）全长２９４ｂｐ，与已发表的德国株（ＧＳ）大小一致，但其核苷酸顺序中有２处发生了变异，均为Ｃ→Ｔ变异。第４３位ＣＡＡ→ＴＡＡ使相应的谷氨酰胺密码子变为终止密码，形成无义突变（Ｎｏｎｓｅｎｓｅｍｕｔａｔｉｏｎ）。将重组质粒中０．３ｋｂ的ＨＰＶ１６Ｅ７基因在表达载体ＰＷＲ５９０－１中进行克隆，经诱导使重组表达质粒在大肠杆菌中高效表达，得到了预计的、分子量约为６９×１０~３的融合蛋白。该蛋白的表达量占菌体总蛋白量的３０％左右。该试验表明ＨＰＶ１６Ｅ７一级结构以及所编码的蛋白多肽在不同的国家和／或不同的地区可能存在着差异。本文首次报道了中国地方株ＨＰＶ１６Ｅ７基因的一级结构。     

Restriction fragment length polymorphisms and sequence variation within the spaP gene of Streptococcus mutans serotype c isolates.

A restriction fragment length polymorphism study was undertaken to determine the extent and location of heterogeneity within spaP encoding the Mr 185,000 cell surface protein P1 (antigen I/II) of Streptococcus mutans serotype c isolates. The gene was found to be highly conserved except for a central variable (V) region predicted to encode less than 150 amino acids. Sequence analysis identified two V-region variants. These differences were independent of the geographic source of the isolates. Southern analysis using synthetic oligonucleotide probes indicated that nonretention of P1 (I/II) by some isolates is not due to a deletion of the 3'-terminal DNA necessary to encode an intact carboxy terminus.     

临床宫颈组织标本HPV16 L1蛋白检测

 目的 检测HPV16阳性宫颈标本L1蛋白的表达,发掘宫颈损伤程度与L1蛋白表达的规律。方法 PCR法对宫颈炎、宫颈上皮内瘤变（CINⅠ~Ⅱ）、原位癌、早期浸润癌及中晚期癌标本进行型别检测,ELISA法及免疫组化法检测HPV16阳性标本中HPV L1蛋白表达。结果 54例宫颈组织中HPV16阳性为46例（85.2%）。随着宫颈损伤加重,HPV16阳性标本的抗原抗体反应逐渐减弱;免疫组化阳性反应仅出现于上皮组织内,反应强度及分布与宫颈损伤程度及癌变组织的分化状态有关。结论 HPV16 L1蛋白的表达同时受宫颈组织损伤程度及宿主细胞分化状态的影响。早期对HPV L1蛋白进行检测,可为宫颈癌的早期预防及临床诊治提供理论指导。     

Evolution of in vitro transformation and tumorigenesis of HPV16 and HPV18 immortalized primary cervical epithelial cells.

Cervical carcinoma develops through a progressive spectrum of premalignant intraepithelial lesions (CIN I-III), the majority of which are associated with human papillomavirus (HPV) types 16 and 18. We established HPV16 and HPV18 immortalized human cervical epithelial cell lines and used them as a model to investigate the genesis and progression of cervical malignancy. The cell lines when cultured in vitro in a system mimicking their in vivo environment exhibit cytologic atypia and a variety of defects in morphologic differentiation at early passage compared to their normal counterparts. With increased passage, these alterations progress to more severe grades, histologically similar to CIN III; however only a limited number of the cell lines are tumorigenic, mimicking the epidemiologic evidence on the rate of conversion from premalignant to invasive carcinoma. The observed changes are not associated with alterations of viral DNA integration or expression and may reflect specific cellular events or changes in virus-host interactions associated with malignant progression.     

Genotyping human papillomavirus type 16 isolates from persistently infected promiscuous individuals and cervical neoplasia patients.

Nucleotide sequence variation in the noncoding region of the genome of human papillomavirus type 16 (HPV16) was determined by direct sequencing and single-strand conformation polymorphism analysis of DNA fragments amplified by PCR. Individuals of diverse sexual promiscuity and/or cervicopathology were studied. In a group of 14 healthy, monogamous HPV16-positive females, only two HPV16 sequence variants could be documented. Among 17 females and 3 males with multiple sex partners and living in the same geographical region, nine sequence variants were found, whereas among 7 patients with cervical neoplasia from another region, five variants were detected. Although numbers are limited, in the group of individuals at high risk of acquiring a sexually transmitted disease or with cervical neoplasia, a larger number of HPV16 sequence variants was encountered (two types among 14 individuals versus nine types among 20; Fisher's exact test, P = 0.07). Seven of the individuals were sampled repeatedly over time. For these persistently infected women, no differences in HPV16 sequences were detected, irrespective of promiscuity, and persistence of a single viral variant, spread over multiple anatomic sites, for more than 2 years could be demonstrated. This indicates that viral persistence may be a common feature and that successful superinfection with a new variant may be rare, despite a potentially high frequency of viral reinoculation.     

Detection of genes encoding internalization-associated proteins in Streptococcus pyogenes isolates from patients with invasive diseases and asymptomatic carriers

A total of 161 Streptococcus pyogenes isolates from patients with invasive infections or from asymptomatic carriers were examined for genes (prtF1, prtF2, and fba) coding for fibronectin-binding proteins to evaluate their involvement in the pathogenesis of different streptococcal manifestations. We found no significant differences in the presence of these three genes between the two groups. Overall, the prtF2 gene was present in similar percentages among strains from both sources (61% versus 63%). Strains carrying the gene fba were slightly more common among those isolated from asymptomatic carriers (72.6% versus 65%). Also, the prtF1 gene was present in a higher, but not significant, percentage among strains from throat swabs than among isolates from invasive infections (75% versus 64.9%). However, this more detailed characterization of the genes encoding fibronectin-binding proteins allowed us to identify a strong association of genes of the erm class, coding for macrolide resistance, with prtF1 and prtF2 rather than with prtF1 alone. Since macrolide resistance was significantly associated with throat swab isolates, it may be hypothesized that proteins coded by prtF1 and prtF2 genes may be synergic in providing support for cell invasion and/or colonizing or persistence efficiency.     

Genetic variability and functional implication of HPV16 from cervical intraepithelial neoplasia in Shanghai women

Human papillomavirus (HPV)16 gene mutation is usually associated with persistent HPV infection and cervical intraepithelial neoplasia (CIN). However, the functional implications of HPV16 mutations remain poorly understood.145 LCR/E6/E7 of the HPV16 isolates were amplified and sequenced, and HPV16 integration status was detected. In total, 89 SNPs (68 in the LCR, 13 in E6, 8 in E7) were discovered, 11 of which were nonsynonymous mutations (8 in E6, 3 in E7). The H85Y and E120D variants in E6 were significantly reduced in the high-grade squamous intraepithelial lesion (HSIL) group compared to the <HSIL group (P = .046 and .005), conversely the N29S in E7(P = .01). Amino acid substitutions (D32N/E, E36Q, H85Y, and E120D in E6 and N29H/S and R77C in E7) were predicted to have an effect on conserved structural and functional residues, and five amino acid substitutions (H85Y, E36Q, I34L, and D32E in E6; R77C in E7) would potentially change the secondary structure. “6329G>T,” a potential binding site for TATA-binding protein, is the most common in LCR variants. A4 (Asian) was associated with an increased risk of HSIL compared to A1–3(P = .009). The H85/E120 in E6 and N29 in HPV16 E7 might play a critical role in carcinogenesis by disrupting p53 and Rb degradation due to affecting their interaction, respectively. In a word, the findings in this study provide preventative and therapeutic interventions of HPV16 -related cervical lesions/cancer.     

人乳头瘤病毒16型长控制区域上YY1位点的缺失可增强病毒对小鼠纤维细胞的转化能力

目的人乳头瘤病毒（Ｈｕｍａｎｐａｐｉｌｏｍａｖｉｒｕｓ，ＨＰＶ）１６型早期启动子Ｐ９７控制着病毒癌基因的表达。为了观测长控制区（Ｌｏｎｇｃｏｎｔｒｏｌｒｅｇｉｏｎ，ＬＣＲ）上ＹＹ１结合位点的破坏对病毒转化能力的影响。方法构建了带有自然发生突变ＬＣＲ序列的ＨＰＶ１６全基因质粒，利用ＥＭＳＡ和荧光素酶实验检测小鼠纤维细胞胞核内源性ＹＹ１蛋白存在和功能状态；将标准及突变的ＨＰＶ１６毒株转染至Ｃ１２７细胞进行软琼脂糖培养基生长实验。结果与上皮类细胞相似，在Ｃ１２７胞核提取物中可检出ＹＹ１蛋白，并且具有良好的ＤＮＡ结合功能和Ｐ９７活性抑制作用。转化实验显示ＹＹ１位点突变ＨＰＶ１６毒株可在软琼脂糖培养基上形成２～１０倍量多的生长集落。结论细胞转录调节因子ＹＹ１存在于啮齿类动物纤维细胞胞核中；ＬＣＲ上ＹＹ１结合位点的破坏可在完整基因组范围内明显增强病毒对小鼠纤维细胞的转化能力。     

HPV16/18和HPV16E6/E7DNA在宫颈癌组织中的表达

目的检测HPV16/18和HPV16E6/E7 DNA在宫颈癌组织中的表达,探讨其在宫颈癌发病中的作用.方法应用PCR和琼脂糖凝胶电泳方法检测46例宫颈癌组织中HPV16/18和HPV16E6/E7DNA.结果 46例宫颈癌中56.5%(26/46)扩增HPV16/18 DNA,其中宫颈鳞癌25例,宫颈腺癌1例.正常对照组20例HPV16/18DNA均为阴性,与宫颈癌组相比差异有显著性(P<0.01).HPV16/18 DNA阳性拷贝对数值为4.32±2.45.HPV16E6,E7DNA分别有53.8%(14/26)、46.2%(12/26)扩增.结论 HPV16/18和HPV16E6/E7 DNA与宫颈癌的发生密切相关,是宫颈癌恶性转化的关键之一,预示着宫颈癌有较强的增殖能力和转移能力.     

Histological and immunocytochemical study of cervical intraepithelial neoplasia (CIN) with associated HPV 6 and HPV 16 infections.

Histological and immunocytochemical features of cervical intraepithelial neoplasia (CIN) associated with HPV 6 and HPV 16, either singly or in combination, were studied in 48 cases. Features of HPV infection (koilocytosis, binucleation, multinucleation, giant irregular nuclei and individual cell dyskeratosis) were present in high prevalence in both HPV 6 and HPV 16 associated CIN. Abnormal mitoses seemed to be a good indicator of CIN and were present in about 50% of cases of CIN associated with either HPV 6 or HPV 16 infection. This finding provides no support for the view held by some investigators that associated HPV 16 infection can be predicted by the presence of abnormal mitoses. Expression of HPV antigen was shown in about 40% of cases with a slight, but not significantly, higher prevalence in cases of combined HPV 6 and HPV 16 infection. Conventional histology and immunocytochemistry could not distinguish CIN associated with HPV 6 from CIN associated with HPV 16 infection.     

High risk HPV load estimated by Hybrid Capture II correlates with HPV16 load measured by real-time PCR in cervical smears of HPV16-infected women.

BACKGROUND: High risk human papillomavirus (HR-HPV) load determined by quantitative methods has already been considered as highly predictive of future development of high grade cervical lesions. Some studies also demonstrated that Hybrid Capture II (HCII) results can be considered as a reflection of HPV DNA load, while others did not. HCI assay, well suited for routine HR-HPV screening, is not especially dedicated for quantitative use. However, we have recently shown that women with high viral loads assessed by HCII were at increased risk of cervical precancer. OBJECTIVES: The aim of the study was to determine if the values given by the HCII assay can be considered as quantitative. STUDY DESIGN: We used a real-time PCR allowing precise quantification of both HPV16 genome and albumin gene to normalize the measuring HPV16 load in cervical cells and to compare the data with those obtained by HCIIin a series of 40 HR-HPV positive samples. RESULTS: Reproducibility of the HPV16 real-time PCR, assessed from nine independent experiments of serial dilutions of SiHa cell DNA, was reflected in coefficients of variation for standard curves of crossing point (Cp) values below 5%. The HPV16 loads with a broad individual variability were significantly related to the cumulative load estimated by HCII and did not depend on the cellularity of samples. CONCLUSIONS: We assume that the HCII values can be used as a quantitative measure of HR-HPV DNA, so long as cervical specimens are collected using standardized protocols.