Continuing global improvement in human papillomavirus DNA genotyping services: The 2013 and 2014 HPV LabNet international proficiency studies.

BACKGROUND: Accurate and internationally comparable human papillomavirus (HPV) DNA detection and typing services are essential for HPV vaccine research and surveillance. OBJECTIVES: This study assessed the proficiency of different HPV typing services offered routinely in laboratories worldwide. STUDY DESIGN: The HPV Laboratory Network (LabNet) has designed international proficiency panels that can be regularly issued. The HPV genotyping proficiency panels of 2013 and 2014 contained 43 and 41 coded samples, respectively, composed of purified plasmids of sixteen HPV types (HPV 6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, 68a and 68b) and 3 extraction controls. Proficient typing was defined as detection in both single and multiple infections of 50 International Units of HPV 16 and HPV 18 and 500 genome equivalents for the other 14 HPV types, with at least 97% specificity. RESULTS: Ninety-six laboratories submitted 136 datasets in 2013 and 121 laboratories submitted 148 datasets in 2014. Thirty-four different HPV genotyping assays were used, notably Linear Array, HPV Direct Flow-chip, GenoFlow HPV array, Anyplex HPV 28, Inno-LiPa, and PGMY-CHUV assays. A trend towards increased sensitivity and specificity was observed. In 2013, 59 data sets (44%) were 100% proficient compared to 86 data sets (59%) in 2014. This is a definite improvement compared to the first proficiency panel, issued in 2008, when only 19 data sets (26%) were fully proficient. CONCLUSION: The regularly issued global proficiency program has documented an ongoing worldwide improvement in comparability and reliability of HPV genotyping services.

A Selective Biomarker Panel Increases the Reproducibility and the Accuracy in Endometrial Biopsy Diagnosis.

Grading and histologic typing of endometrial cancer in biopsy material has a direct impact on the decision to perform lymphadenectomy and/or omentectomy in many cancer centers. Endometrial biopsies are among the most common general surgical pathology specimens. Multiple studies have shown that biopsy diagnosis suffers from a lack of reproducibility. Although many biomarkers have been proposed, none have been demonstrated to improve the diagnosis in the biopsy setting. In this study, 70 biopsies with endometrial carcinoma were supplemented with a biomarker panel consisting of ER, PR, P53, and DNA ploidy. A representative H&E slide was scanned digitally and made available to 12 gynecologic pathologists in 4 Nordic countries: Finland, Denmark, Sweden, and Norway. Reviewers diagnosed the cases both before and after being provided with the biomarker results. The interobserver percent agreement and Cohen κ improved from 75.8% (κ=0.52, moderate) to 84% (κ=0.68, substantial) with inclusion of the biomarker panel. Agreement with the subsequent hysterectomy diagnosis also improved from 83.6% (κ=0.67) to 88.7% (κ=0.77). There was no statistical improvement between a reflex (84% agreement) and a reflective testing algorithm (82.9% agreement), suggesting that the selective use of biomarkers is appropriate. Difficult cases were almost exclusively high-grade tumors. Finally, a statistical model indicated that only P53 and DNA ploidy, in conjunction with an H&E review, had an impact on the decision to upgrade or downgrade cases.

Prevalence and genotype distribution of cervical human papillomavirus (HPV) among women in urban Tianjin, China.

To investigate the prevalence and genotype distribution of human papillomavirus (HPV) infection among women in urban Tianjin, China. A cervical cancer screening program for 2,000 women aged 21-65 years old was performed in urban Tianjin from April to October in 2013. The program included ThinPrep cytologic tests (TCT), HPV DNA detection and genotyping using nested polymerase chain reaction (PCR) combined with Pyrosequencing technology. Colposcopy examination and biopsy were needed if TCT reported greater or equal atypical cells of undetermined significance (ASCUS). One thousand nine hundred seventy-eight women were enrolled in the final study, 14.71% (291/1,978) of women were tested HPV positive. Of HPV-positive specimens, 248 (85.22%) and 43 (14.78%) were infected with high- and low-risk HPV genotypes, respectively. Twenty-eight types of HPV were detected in all, the most frequently detected types were HPV16, 58, 18, and 66 orderly. The single infection rate was 92.28% among HPV-positive samples while the multiple infection rate was 7.72%. Among multiple infection models, HPV16 was the most common type co-infection with other types. This study is, to our knowledge, the first population-based survey to provide data on HPV infection and genotype distribution among women in urban Tianjin, China. There was a high prevalence of HPV infection in this area, and HPV16, 58, 18, 66 were the most frequently detected genotypes. Our study provide important information regarding the necessity of early cervical cancer screenings and prophylactic HPV vaccinations, and the knowledge of HPV distribution can also inform us about the HPV ecological change after the vaccination.

Expression of the p53 target Wig-1 is associated with HPV status and patient survival in cervical carcinoma.

The p53 target gene WIG-1 (ZMAT3) is located in chromosomal region 3q26, that is frequently amplified in human tumors, including cervical cancer. We have examined the status of WIG-1 and the encoded Wig-1 protein in cervical carcinoma cell lines and tumor tissue samples. Our analysis of eight cervical cancer lines (Ca Ski, ME-180, MS751, SiHa, SW756, C-4I, C-33A, and HT-3) by spectral karyotype, comparative genomic hybridization and Southern blotting revealed WIG-1 is not the primary target for chromosome 3 gains. However, WIG-1/Wig-1 were readily expressed and WIG-1 mRNA expression was higher in the two HPV-negative cervical cell lines (C33-A, HT-3) than in HPV-positive lines. We then assessed Wig-1 expression by immunohistochemistry in 38 cervical tumor samples. We found higher nuclear Wig-1 expression levels in HPV-negative compared to HPV positive cases (p = 0.002) and in adenocarcinomas as compared to squamous cell lesions (p<0.0001). Cases with moderate nuclear Wig-1 staining and positive cytoplasmic Wig-1 staining showed longer survival than patients with strong nuclear and negative cytoplasmic staining (p = 0.042). Nuclear Wig-1 expression levels were positively associated with age at diagnosis (p = 0.023) and histologic grade (p = 0.034). These results are consistent with a growth-promoting and/or anti-cell death function of nuclear Wig-1 and suggest that Wig-1 expression can serve as a prognostic marker in cervical carcinoma.

Global improvement in genotyping of human papillomavirus DNA: the 2011 HPV LabNet International Proficiency Study.

Accurate and internationally comparable human papillomavirus (HPV) DNA genotyping is essential for HPV vaccine research and for HPV surveillance. The HPV Laboratory Network (LabNet) has designed international proficiency studies that can be issued regularly and in a reproducible manner. The 2011 HPV genotyping proficiency panel contained 43 coded samples composed of purified plasmids of 16 HPV types (HPV6, -11, -16, -18, -31, -33, -35, -39, -45, -51, -52, -56, -58, -59, -66, -68a, and -68b) and 3 extraction controls. Tests that detected 50 IU of HPV16 and HPV18 and 500 genome equivalents for the other 14 HPV types in both single and multiple infections were considered proficient. Ninety-six laboratories worldwide submitted 134 data sets. Twenty-five different HPV genotyping assay methods were used, including the Linear Array, line blot/INNO-LiPA, PapilloCheck, and PCR Luminex assays. The major oncogenic HPV types, HPV16 and HPV18, were proficiently detected in 97.0% (113/116) and 87.0% (103/118) of the data sets, respectively. In 2011, 51 data sets (39%) were 100% proficient for the detection of at least one HPV type, and 37 data sets (28%) were proficient for all 16 HPV types; this was an improvement over the panel results from the 2008 and 2010 studies, when <25 data sets (23% and 19% for 2008 and 2010, respectively) were fully proficient. The improvement was also evident for the 54 laboratories that had also participated in the previous proficiency studies. In conclusion, a continuing global proficiency program has documented worldwide improvement in the comparability and reliability of HPV genotyping assay performances.

The 2010 global proficiency study of human papillomavirus genotyping in vaccinology.

Accurate and internationally comparable human papillomavirus (HPV) DNA genotyping is essential both for evaluation of HPV vaccines and for effective monitoring and implementation of vaccination programs. The World Health Organization (WHO) HPV Laboratory Network (LabNet) regularly issues international proficiency studies. The 2010 HPV genotyping proficiency panel for HPV vaccinology contained 43 coded samples composed of purified plasmids of 16 HPV types (HPV types 6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68a and 68b) and 3 coded extraction controls. Proficient typing was defined as detection in both single and multiple infections of 50 international units (IU) of HPV type 16 (HPV-16) and HPV-18 DNA and 500 genome equivalents (GE) for the other 14 HPV types. Ninety-eight laboratories worldwide submitted a total of 132 data sets. Twenty-four different HPV genotyping assay methods were used, with Linear Array being the most commonly used. Other major assays used were a line blot assay (Inno-LiPa), CLART, type-specific real-time PCR, PCR Luminex, and different microarray assays. Altogether, 72 data sets were proficient for detection of more than 1 type, and only 26 data sets proficiently detected all 16 HPV types. The major oncogenic HPV types, 16 and 18, were proficiently detected in 95.0% (114/120) and 87.0% (94/108) of data sets, respectively. Forty-six data sets reported multiple false-positive results and were considered nonproficient. A trend toward increased sensitivity of assays was seen for the 41 laboratories that participated in both 2008 and 2010. In conclusion, continued global proficiency studies will be required for establishing comparable and reliable HPV genotyping services for vaccinology worldwide.

E6/E7 mRNA expression analysis: a test for the objective assessment of cervical adenocarcinoma in clinical prognostic procedure.

Detection of E6/E7 mRNA expression using the real-time nucleic acid sequence-based amplification assay (NASBA) PreTect HPV-Proofer was compared with results of human papillomavirus (HPV) DNA detection in 98 paraffin-embedded samples from patients with cervical adenocarcinoma. HR-HPV DNA was detected in 61 (62%), while HR-HPV E6/E7 mRNA was detected in 63 (64%) of the samples. Correlation between results from DNA analyses and the E6/E7 mRNA assay showed consistent results in 87% of samples (47 of 54). The results from these two methods in detecting presence of HPV infection of any type agreed in 77%. Overall agreement between the methods was seen in 82 of the 98 cases (84%). When evaluating change in sensitivity for detection of HPV positives by adding more HPV types to the HPV DNA assay, maximum sensitivity was reached by targeting four HPV types. The coverage of HPV DNA presence was 76.9%, while the E6/E7 mRNA assay achieved a maximum coverage of 80.8% using only three HPV types. Thus, E6/E7 oncogene expression analysis may provide a more objective test for assessment of neoplastic glandular cells. Further studies may reveal whether the clinical performance of the E6/E7 mRNA assay will be of prognostic value in management of cervical adenocarcinoma.

Articular cartilage regeneration with autologous marrow aspirate and hyaluronic Acid: an experimental study in a goat model.

PURPOSE: The purpose of the study was to determine whether postoperative intra-articular injections of autologous marrow aspirate (MA) and hyaluronic acid (HA) after subchondral drilling resulted in better cartilage repair as assessed histologically by Gill scoring. METHODS: In a goat model we created a 4-mm full-thickness articular cartilage defect in the stifle joint (equivalent to 1.6 cm in the human knee) and conducted subchondral drilling. The animals were divided into 3 groups: group A (control), no injections; group B (HA), weekly injection of 1 mL of sodium hyaluronate for 3 weeks; and group C (HA + MA), similar to group B but with 2 mL of autologous MA in addition to HA. MA was obtained by bone marrow aspiration, centrifuged, and divided into aliquots for cryopreservation. Fifteen animals were equally divided between the groups and sacrificed 24 weeks after surgery, when the joint was harvested, examined macroscopically and histologically. RESULTS: Of the 15 animals, 2 from group A had died of non-surgery-related complications and 1 from group C was excluded because of a joint infection. In group A the repair constituted mainly scar tissue, whereas in group B there was less scar tissue, with small amounts of proteoglycan and type II collagen at the osteochondral junction. In contrast, repair cartilage from group C animals showed almost complete coverage of the defect with evidence of hyaline cartilage regeneration. Histology assessed by Gill scoring was significantly better in group C with 1-way analysis of variance yielding an F statistic of 10.611 with a P value of .004, which was highly significant. CONCLUSIONS: Postoperative intra-articular injections of autologous MA in combination with HA after subchondral drilling resulted in better cartilage repair as assessed histologically by Gill scoring in a goat model. CLINICAL RELEVANCE: After arthroscopic subchondral drilling, this novel technique may result in better articular cartilage regeneration.

Detection of genomic amplification of the human telomerase gene TERC, a potential marker for triage of women with HPV-positive, abnormal Pap smears.

The vast majority of invasive cervical carcinomas harbor additional copies of the chromosome arm 3q, resulting in genomic amplification of the human telomerase gene TERC. Here, we evaluated TERC amplification in routinely collected liquid based cytology (LBC) samples with histologically confirmed diagnoses. A set of 78 LBC samples from a Swedish patient cohort were analyzed with a four-color fluorescence in situ hybridization probe panel that included TERC. Clinical follow-up included additional histological evaluation and Pap smears. Human papillomavirus status was available for all cases. The correlation of cytology, TERC amplification, human papillomavirus typing, and histological diagnosis showed that infection with high-risk human papillomavirus was detected in 64% of the LBC samples with normal histopathology, in 65% of the cervical intraepithelial neoplasia (CIN)1, 95% of the CIN2, 96% of the CIN3 lesions, and all carcinomas. Seven percent of the lesions with normal histopathology were positive for TERC amplification, 24% of the CIN1, 64% of the CIN2, 91% of the CIN3 lesions, and 100% of invasive carcinomas. This demonstrates that detection of genomic amplification of TERC in LBC samples can identify patients with histopathologically confirmed CIN3 or cancer. Indeed, the proportion of TERC-positive cases increases with the severity of dysplasia. Among the markers tested, detection of TERC amplification in cytological samples has the highest combined sensitivity and specificity for discernment of low-grade from high-grade dysplasia and cancer.

Mutation of PIK3CA: possible risk factor for cervical carcinogenesis in older women.

PIK3CA encodes the p110alpha catalytic subunit of PI 3-kinase, which regulates signaling pathways important for neoplasia, cell proliferation and apoptosis. Somatic mutations in this gene have been detected in several solid human tumors. We investigated these mutations in cervical carcinoma and its precursors, and their association with HPV infection and patient clinical data. The mutations were analyzed using post-PCR direct genomic DNA sequencing. Samples included 9 cervical cancer cell lines, 184 invasive cervical carcinomas, and 30 cervical neoplasias. Missense mutations of PIK3CA were identified in 15/184 (8.15%) invasive cervical carcinomas. One novel mutation G1638C (Q546H) was found. Three mutations were identified in the cervical cancer lines. No mutations were found in the precursors. The difference in mutation frequency between invasive and pre-invasive lesions was not significant (p=0.1372). In relation to age and HPV, the mutation rate was significantly higher in patients>or=60 years (p=0.001), while the rate of HPV infection was higher in patients

Characterization of humoral immune responses against p16, p53, HPV16 E6 and HPV16 E7 in patients with HPV-associated cancers.

The cellular tumor suppressor p16 is strongly overexpressed in cervical cancers and precancers. We have previously demonstrated that infiltrating T lymphocytes reactive against p16 can be found in cervical cancer patients. Here, we analyzed whether p16 induces humoral immune responses. Sera of patients with cervical cancer, oropharyngeal cancer, colorectal cancer and autoimmune disease were included. A total of 919 sera were analyzed, including 486 matched sera from a cervical cancer case control study. p16 antibodies were analyzed in Western blot and a newly developed peptide ELISA covering the complete p16 protein. In addition, a Luminex-based multiplex assay was used for simultaneous detection of antibodies directed against p16, p53, HPV16 E6 and HPV16 E7. In all entities, only low p16 antibody reactivity was observed. Epitope mapping revealed 2 predominant epitope regions of the p16 protein. No significant difference in p16 antibody frequency (OR = 0.9; 95% CI = 0.6-1.3) and p53 antibody frequency (OR = 0.6; 95% CI = 0.3-1.2) was found between patients and healthy controls in the cervical cancer case control study. Antibodies against the HPV16 oncoproteins E6 and E7 were detected more frequently in cervical cancer patients when compared with healthy controls (E6 OR = 27.8; 95% CI = 11.1-69.7, E7 OR = 5.7; 95% CI = 2.9-11.1). In conclusion, despite the strong expression of p16 and the observed induction of cellular immune responses, antibody reactivity against p16 was observed only at very low levels independent of the disease background.

Expression of p16INK4a and MIB-1 in relation to histopathology and HPV types in cervical adenocarcinoma.

A total of 101 primary cervical adenocarcinomas were analyzed for the presence of p16INK4a and MIB-1 expression in correlation with the presence of 'high-risk' types of human papillomavirus (HR-HPV) and clinical outcome. We found that adenocarcinoma grading showed a significant negative correlation to p16INK4a levels (p=0.001): i.e. we found less intense p16 staining in poorly differentiated tumors than in more highly differentiated tumors as well as a highly significant correlation between HPV infection and higher levels of p16INK4a staining (p=0.00), which was similar for different HPV-types. Tumor suppressor protein p16INK4a levels were higher in HPV positive than in HPV negative tumors. Higher levels of the proliferation marker MIB-1 were associated with poorer outcome. Higher MIB-1 levels were seen in tumors with a lower grade and higher stage at diagnosis. Moreover, MIB-1 levels seem to be higher in tumors due to infection with HPV 16 and 18 compared with HPV 45. MIB-1 may be a helpful marker in grading adenocarcinoma: a high level of expression of MIB-1 indicates a low grade of tumor, whereas high expression of p16INK4a indicates a highly differentiated of the tumor. Thus, immunostaining for p16INK4a appears to be a useful diagnostic tool for cervical adenocarcinoma.

Does HPV-status 6-12 months after treatment of high grade dysplasia in the uterine cervix predict long term recurrence?

BACKGROUND: Women once treated for high grade cervical dysplasia have a high long term risk for developing new dysplasia or cancer. OBJECTIVES: To investigate if human papilloma virus (HPV)-negativity after treatment of cervical dysplasia reduces the need for frequent long term follow up. DESIGN: Case/control study based on archival smears. METHODS: Women with cervical intraepithelial neoplasi (CIN)2-3, treated for dysplasia and with recurrence of CIN2+ more than 2 years after treatment were compared with controls without recurrence, matched for age and date of treatment. High risk-HPV-DNA were analysed with PCR from two archival smears per woman. Mean follow up time was 14.6 years. RESULTS: 24% (45/189) of cases and 11% (43/378) of controls were HPV-positive in any of two smears. Odds ratio (OR)=2.5 (1.6-3.8). CONCLUSION: HPV-status 6-12 months after treatment of high grade dysplasia is of limited value for the design of long term follow up.

Genetic polymorphism of chemokine receptors CCR2 and CCR5 in Swedish cervical cancer patients.

Chemokines are chemotactic cytokines that orchestrate leukocyte trafficking in tissues, thus, playing an important role in regulation of immunological processes. The aim of this study was to investigate the association of human papillomavirus (HPV) infection and cervical cancer with two DNA polymorphisms of the chemokine receptors CCR5-delta32 and CCR2-64I. The study material consisted of 50 cervical intraepithelial neoplasia (CIN) cases and 50 of age and sampling-date matched controls, 100 invasive cervix cancer cases and 100 of their corresponding matched disease-free controls. Pyrosequencing was employed to genotype the CCR2-64I polymorphism. CCR5-delta32 was genotyped using standard PCR fragment length analysis. The frequencies of CCR2 and CCR5 genotypes from 150 patients and 150 healthy controls were representative of the general population according to the Hardy-Weinberg equilibrium analysis. Risk association was computed with conditional logistic regression analysis. HPV-positive individuals with the rare CCR5deelta32/delta32 genotype have a risk of 4.58 (CI = 0.40-52.64, p-value = 0.045) compare to HPV negative group. The delta-32 mutation on the CCR locus is imperceptibly associated with increased risk of HPV infection. In total, cervical neoplasia was not associated with genetic polymorphism of CCR2 and CCR5.

p16INK4a and laminin-5gamma2 chain expression during the progression of cervical neoplasia.

p16INK4a, laminin-5gamma2 chain, and PCNA were investigated to compare the expression levels in relation to histological diagnosis and time for progression. The material consisted of 37 normal cervical tissues, 35 with different grades of CIN, and 11 invasive cervical cancers. Our results showed a reduction of basement membrane staining for laminin-5gamma2 chain from 78.4% in normal squamous epithelium to 27.8% in CIN3 (p < 0.001). The intracytoplasmic staining for laminin-5gamma2 chain increases with severity of lesion. The same trend was observed with p16INK4a and PCNA expression (p < 0.001). Co-expression of p16INK4a and PCNA was seen in 85.7% of samples. Cases that were laminin-5gamma2 chain BM - /p16INK4a+/PCNA+ have the shortest interval time (average: 46.8+/-36.3 months) for progression, while cases with laminin-5gamma2 chain BM + /p16INK4a-/PCNAPCNA--have the longest time interval (average: 110.2+/-52.7 months) (p < 0.05). Thus co-expression of p16INK4a, laminin-5gamma2 chain and PCNA may be valuable for the prediction progression of cervical neoplasia.

Sentinel-base DNA genotyping using multiple sequencing primers for high-risk human papillomaviruses.

Despite the various technologies in place for genotyping human papillomaviruses (HPV), clinical use and clinical research demand a method that is fast, more reliable and cost-effective. The technology described here represents a breakthrough development in that direction. By combining the method of multiple sequencing primers with DNA sequencing, we have developed a rapid assay for genotyping HPV that relies on the identification of a single, type-specific 'sentinel' base. As described here, the prototype assay has been developed to recognize the 12 most high-risk HPV types (HPV-16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58 and 59) and is capable of recognizing and simultaneously genotyping multiple HPV co-infections. By providing sequence information on multiple HPV infections, this method eliminates the need for labor- and cost-intensive PCR cloning. These proof-of-concept studies establish the assay to be accurate, reliable, rapid, flexible, and cost-effective, providing evidence of the feasibility this technique for use in clinical settings.

Tag-array based HPV genotyping by competitive hybridization and extension.

A method is described for HPV genotyping based on multiplex competitive hybridization (MUCH) combined with apyrase mediated allele-specific extension (AMASE). Two type-specific oligonucleotides were designed for each of the 23 investigated HPV types and directed towards two highly inter-type heterogeneous regions. The type-specific oligonucleotides were allowed to compete in the hybridization to an immobilized template resulting in a highly specific hybridization process. To increase further the specificity, a second step of type discrimination was used in which specific extension of 3'-termini matched oligonucleotides was performed. The 46 type-specific oligonucleotides each had a unique tag sequence to allow detection via an array of oligonucleotides complementary to the tags. To evaluate the genotyping assay, a total of 92 HPV positive samples were tested in this study. Twelve had double infections and five had three to five coexisting HPV types. The results show that MUCH-AMASE can readily detect multiple infections, whereas conventional dideoxy sequencing resulted in ambiguous sequence. Four samples with three to five genotypes detected were cloned and individual clones were sequenced. The cloning procedure verified the MUCH-AMASE results with indications that we can find minor infections (<2% relative amounts). We can thus conclude that the developed assay is highly sensitive, with improved throughput and with excellent possibility to detect multiple infections.

Type-specific multiple sequencing primers: a novel strategy for reliable and rapid genotyping of human papillomaviruses by pyrosequencing technology.

DNA sequencing is the gold standard method for accurate microbial and viral typing. However, DNA sequencing techniques have been facing limitations in typing of human papillomaviruses when the specimen harbors multiple genotypes and yields nonspecific amplification products, resulting in nonspecific and noninterpretable sequence data. To address these limitations we have developed a type-specific multiple sequencing primer DNA-sequencing method. This new strategy is suitable for sequencing and typing of samples harboring different genotypes (co-infections with multiple genotypes) and yielding nonspecific amplifications, thus eliminating the need for nested polymerase chain reaction (PCR), stringent PCR conditions, and cloning. The new approach has also proved useful for amplicons containing low PCR yield or subdominant types, avoiding reperforming of amplifications. We have applied the multiple sequencing primer method for genotyping of clinically relevant human papillomaviruses in a clinical test panel by using a combined pool of seven type-specific sequencing primers for HPV-6, -11, -16, -18, -31, -33, and -45. Furthermore, we introduced a sequence pattern recognition approach when there was a plurality of genotypes in the sample to facilitate typing of more than one target DNA in the sample. The multiple sequencing primer method has proved to be a multifaceted approach for typing of human papillomaviruses by DNA sequencing technologies.

p16INK4A and p14ARF expression pattern by immunohistochemistry in human papillomavirus-related cervical neoplasia.

Human papillomavirus is known to play an important etiological role in the genesis of cervical cancer, but only a very small proportion of infected women develop invasive cervical cancer. The purpose of cervical cancer prevention is early diagnosis of its precursors. The molecular detection of human papillomavirus DNA as a diagnostic test to cervical carcinogenesis gave a low positive predictive value as compared to the use of biomarkers. p16INK4A and possibly p14ARF have been proposed as putative surrogate biomarkers that would allow identification of dysplastic cervical epithelia. Serial consecutive biopsies representing normal cervical epithelium to cervical intraepithelial neoplasia and/or invasive cervical cancer were stained with immunohistochemistry for p16INK4A, p14ARF and proliferating cell nuclear antigen. The positive rates of these markers were significantly higher in cervical intraepithelial neoplasia and in squamous cell carcinoma than in normal cervix (P<0.01). No significant difference was noted between lesions progressing from cervical intraepithelial neoplasia to squamous cell carcinoma for both p16INK4A and p14ARF expression (P>0.05). For both biomarkers, nuclear staining was predominantly seen. However, the cytoplasmic stain of p16INK4A increased with disease progression and the pattern of expression varied between different tumors and its location within the lesion. Both nuclear and cytoplasmic staining with p16INK4A and p14ARF of affected epithelial cells were considered positive. In the adjacent normal tissue to cervical neoplasia, the positive rates of p16INK4A, p14ARF and proliferating cell nuclear antigen expression were higher than those found distant to these lesions but the findings did not reach statistical significance. No correlation was seen between the human papillomavirus types detected and the expression of p16INK4a and p14ARF. In conclusion, overexpression of p16INK4A and p14ARF act as potential biomarkers for cervical cancer progression from premalignant lesions.

Telomere attrition predominantly occurs in precursor lesions during in vivo carcinogenic process of the uterine cervix.

Although human papillomavirus (HPV) has been defined as the pathogen for cervical carcinomas, molecular events underlying the oncogenic process are unclear. As telomere dysfunction-mediated chromosomal instability and telomerase activation have been suggested as key events in carcinogenesis, we dissected the dynamic changes in telomere length, checkpoint response, and temporal profile of telomerase expression during the evolution from precursor lesions (cervical intraepithelial neoplasia, CINs) to invasive cancers of the uterine cervix in sequential samples from 16 patients. Telomeres were significantly shortened in all CIN samples and no further substantial attritions occurred in most cases with the acquisition of malignant phenotype. Very short telomeres were coupled with constitutive activation of the DNA damage response pathway (Chk2 phosphorylation) and increased cellular proliferation in those cervical specimens. Telomerase reverse transcriptase (hTERT) expression was preferably induced at advanced CINs or invasive cancers. The present finding demonstrates that excessive telomere shortening predominantly occurs in the early carcinogenesis of the uterine cervix largely prior to telomerase activation. Widespread over-erosion of telomeres or telomere dysfunction in very early stages of cervical tumorigenesis might fuel transformation processes by driving chromosomal instability.