Viral markers in nasopharyngeal carcinoma: A systematic review and meta-analysis on the detection of p16INK4a, human papillomavirus (HPV), and Ebstein-Barr virus (EBV).

PURPOSE: This study aimed to conduct a meta-analysis to investigate the distribution of EBV and HPV stratified according to histological NPC type. MATERIALS & METHODS: We performed a meta-analysis to produce pooled prevalence estimates in a random-effects model. We also performed calculations for attributable fractions of viral combinations in NPC, stratified according to histological type. RESULTS: There was a higher prevalence of HPV DNA in WHO Type I (34.4%) versus WHO Type II/III (18.4%). The attributable fractions of WHO Type I NPC was predominantly double negative EBV(-) HPV(-) NPC (56.4%), and EBV(-) HPV(+) NPC (21.5%), in contrast to the predominant infection in WHO Type II/III which was EBV(+) HPV(-) NPC (87.5%). Co-infection of both EBV and HPV was uncommon, and double-negative infection was more common in WHO Type I NPC. CONCLUSION: A significant proportion of WHO Type I NPC was either double-negative EBV(-)HPV(-) or EBV(-)HPV(+).

Meta-analysis on the performance of p16/Ki-67 dual immunostaining in detecting high-grade cervical intraepithelial neoplasm.

AIM: Although routine screening contributes to substantial reductions in cervical cancer morbidity and mortality, the low specificity of HPV detection and limited sensitivity of cervical cytology necessitates the application of more optimized markers, such as the newly-introduced p16/Ki-67 dual-staining method. Here we reviewed several studies to evaluate the performance of this method in cervical cancer screening. METHODS: An electronic database search was performed on PubMed, Web of Science, CNKI and Wanfang Database for studies assessing p16/Ki-67 dual immunostaining in the diagnosis of high-grade cervical intraepithelial neoplasm (HGCIN) with abnormal cytological morphologies. Two reviewers screened literatures, extracted data and assessed the quality of the included studies independently. Meta-analysis was performed using ReV. Man 5.2 and Meta-DiSc 1.2 software packages. RESULTS: The absolute sensitivity of p16/Ki-67 dual staining for diagnosing HGCIN ranged from 80% to 94%, while the sensitivity of triage method with hrHPV testing ranged from 78% to 96%. The specificity of p16/Ki-67 testing and hrHPV detection for predicting absence of CIN2+ ranged from 39% to 79% and 15% to 44%, respectively. Quantitative meta-analysis showed that the pooled sensitivity of p16/ki-67 dual staining is 0.88 [95'CI (0.86-0.90)], the pooled specificity is 0.58 [95'CI (0.56-0.60)]. For hrHPV testing, the pooled sensitivity and pooled specificity is 0.94 [95'CI (0.93-0.96)] and 0.32 [95'CI (0.29-0.34)], respectively. CONCLUSIONS: p16/Ki-67 dual immunostaining had comparable sensitivity and improved specificity in screening HGCIN or CC when compared with hrHPV detection. Further studies may be beneficial to assess the efficacy of this novel biomarker, which can be potentially used as one of the initial screening assays.

[Diagnostic value of p16/mcm2 dual staining in cervical intraepithelial neoplasia and its association with high-risk HPV infection].

Objective: To study the expression of p16/mcm2 immunocytochemical dual staining in cervical lesions and its association with high-risk HPV infection, and discuss its clinical value in cervical cancer screening. Methods: From May to December 2015, a total of 1 127 women receiving cervical cancer screening, high-risk HPV (HR-HPV) test and liquid-based cytology test were included in the study. p16/mcm2 immunocytochemical dual staining was performed on residual cytology specimens and the results were compared with histopathology results. Results: p16/mcm2 had a higher expression risk in HPV16/18 group and other HR-HPV group compared with HPV negative group, with OR of 15.95 (95%CI: 9.59-26.51) and 10.53 (95%CI: 7.41-14.98), respectively. The positive rate of p16/mcm2 increased with cervical intraepithelial neoplasia (CIN) severity, and was higher in both CIN2 group and CIN3 group than in benign lesion group (P<0.05). The overall sensitivity of p16/mcm2 to detect CIN2+and CIN3+lesions were 86.1% and 92.0%, respectively, and the overall specificity were 46.1% and 44.4%, respectively. In group with cytologic diagnoses of atypical squamous cells (ASC) and low-grade squamous intraepithelial lesion (LSIL), the sensitivity to detect CIN2+and CIN3+lesions were 85.7% and 87.5%, respectively, and the specificity were 45.5% and 44.1%, respectively. Conclusions: p16/mcm2 dual staining has higher sensitivity than cytology test and better specificity than HPV test. It can identify high-grade cervical lesions and guide the classification of CIN. p16/mcm2 might be used as an innovative biomarker for cervical cancer screening.

HPV16 genotype, p16/Ki-67 dual staining and koilocytic morphology as potential predictors of the clinical outcome for cervical low-grade squamous intraepithelial lesions.

OBJECTIVE: To evaluate the association of human papillomavirus (HPV) 16 and non-16 genotype, p16/Ki-67 dual staining and koilocytosis and their role in the prediction of the clinical outcome of low-grade squamous intraepithelial lesion (LSIL) cytology. METHODS: One hundred and fifty-five patients with LSIL were followed up and recorded as progression, persistence or regression. HPV genotyping was performed for high-risk HPV (hrHPV) DNA-positive cases. Koilocytosis was reviewed and p16/Ki-67 dual staining was performed on reprocessed conventional cytology slides. RESULTS: HPV16 was the most frequent genotype found in 16.3% of cases. p16/Ki-67 dual staining was positive in 36.1% of all cases. Progression, including concurrent cervical intraepithelial lesion grade 2 or above (CIN2+), was recorded in 13.8% of cases. A statistically significant difference between progressive and non-progressive cases was shown by the following: hrHPV-positive versus hrHPV-negative (P = 0.022), HPV16-positive versus non-16 HPV-positive (P < 0.001) and p16/Ki-67-positive versus p16/Ki-67-negative (P < 0.001) cases. Cases with combined HPV16 and p16/Ki-67 positivity showed the highest progression rate (58.3%). Non-koilocytic HPV16-positive cases showed a 50% progression rate compared with 10.1% for koilocytic non-16 HPV-positive cases (P = 0.010). The sensitivity of p16/Ki-67 dual staining for the detection of CIN2+ lesions was 80%, comparable with hrHPV (85%). The specificity of p16/Ki-67 dual staining was 71% and of hrHPV 42%. The highest specificity was found for HPV16 genotype presence (91%), but with low sensitivity (50%). CONCLUSION: HPV genotyping, p16/Ki-67 dual staining and koilocytic morphology can be useful in the prediction of clinical outcome in women initially diagnosed with LSIL cytology.

HPV DNA, E6/E7 mRNA, and p16INK4a detection in head and neck cancers: a systematic review and meta-analysis.

BACKGROUND: We aimed to provide updated information about the global estimates of attributable fraction and type distribution of human papillomavirus (HPV) in head and neck squamous cell carcinomas by doing a systematic review and meta-analysis. METHODS: We did a literature search on PubMed to identify studies that used PCR for detection of HPV DNA in head and neck squamous cell carcinomas with information about HPV genotype distribution. We included studies that tested 20 or more biopsies per cancer site and were published between July 15, 1990, and Feb 29, 2012. We collected information about sex, risk factors, HPV detection methods, and biomarkers of potentially HPV-induced carcinogenesis (E6/E7 mRNA and p16(INK4a)). If it was not possible to abstract the required information directly from the paper, we contacted the authors. We did a meta-analysis to produce pooled prevalence estimates including a meta-regression to explore sources of heterogeneity. FINDINGS: 148 studies were included, contributing data for 12 163 cases of head and neck squamous cell carcinoma from 44 countries. HPV DNA was detected in 3837 cases. HPV16 accounted for 82·2% (95% CI 77·7-86·4) of all HPV DNA positive cases. By cancer site, pooled HPV DNA prevalence estimates were 45·8% (95% CI 38·9-52·9) for oropharynx, 22·1% (16·4-28·3) for larynx (including hypopharynx), and 24·2% (18·7-30·2) for oral cavity. The percent positivity of p16(INK4a) positive cases in HPV-positive oropharyngeal cancer cases was 86·7% (95% CI 79·2-92·9) and of E6/E7 mRNA positive cases was 86·9% (73·2-96·8). The estimate of HPV attributable fraction in oropharyngeal cancer defined by expression of positive cases of E6/E7 mRNA was 39·8% and of p16(INK4a) was 39·7%. Of subsites, tonsils (53·9%, 95% CI 46·4-61·3) had the highest HPV DNA prevalence. HPV DNA prevalence varied significantly by anatomical site, geographic region, but not by sex or tobacco or alcohol consumption. INTERPRETATION: The contribution of HPV prevalence in head and neck squamous cell carcinoma and in particular that of HPV16 in the oropharynx shows the potential benefit of prophylactic vaccines. FUNDING: European Commission.

Impact of tumor HPV status on outcome in patients with recurrent and/or metastatic squamous cell carcinoma of the head and neck receiving chemotherapy with or without cetuximab: retrospective analysis of the phase III EXTREME trial.

BACKGROUND: Tumor human papillomavirus (HPV) status is an important prognostic factor in locoregionally advanced squamous cell carcinoma of the head and neck (SCCHN). Prognostic value in recurrent and/or metastatic (R/M) disease remains to be confirmed. This retrospective analysis of the EXTREME trial, comparing chemotherapy plus cetuximab with chemotherapy first line in R/M SCCHN, investigated efficacy and prognosis according to tumor p16 and HPV status. PATIENTS AND METHODS: Paired tissue samples were used: p16INK4A expression was assessed by immunohistochemistry, and HPV status determined in extracted DNA samples using oligonucleotide hybridization assays. RESULTS: Altogether, 416 of 442 patients had tumor samples available for p16 and HPV: 10% of tumors were p16 positive and 5% were HPV positive. Adding cetuximab to chemotherapy improved survival, irrespective of tumor p16 or HPV status. This pattern remained in a combined analysis of p16 and HPV. p16 positivity and HPV positivity were associated with prolonged survival compared with p16 negativity and HPV negativity. Subgroup analysis of patients with oropharyngeal cancer demonstrated a similar pattern to all evaluable patients. CONCLUSION: The results from this analysis suggest that p16 and HPV status have prognostic value in R/M SCCHN and survival benefits of chemotherapy plus cetuximab over chemotherapy alone are independent of tumor p16 and HPV status.

Chromogenic in situ hybridization and p16/Ki67 dual staining on formalin-fixed paraffin-embedded cervical specimens: correlation with HPV-DNA test, E6/E7 mRNA test, and potential clinical applications.

Although HPV-DNA test and E6/E7 mRNA analyses remain the current standard for the confirmation of human papillomavirus (HPV) infections in cytological specimens, no universally adopted techniques exist for the detection of HPV in formalin-fixed paraffin-embedded samples. Particularly, in routine laboratories, molecular assays are still time-consuming and would require a high level of expertise. In this study, we investigated the possible use of a novel HPV tyramide-based chromogenic in situ hybridization (CISH) technology to locate HPV on tissue specimens. Then, we evaluate the potential usefulness of p16(INK4a)/Ki-67 double stain on histological samples, to identify cervical cells expressing HPV E6/E7 oncogenes. In our series, CISH showed a clear signal in 95.2% of the specimens and reached a sensitivity of 86.5%. CISH positivity always matched with HPV-DNA positivity, while 100% of cases with punctated signal joined with cervical intraepithelial neoplasia grade 2 or worse (CIN2+). p16/Ki67 immunohistochemistry gave an interpretable result in 100% of the cases. The use of dual stain significantly increased the agreement between pathologists, which reached 100%. Concordance between dual stain and E6/E7 mRNA test was 89%. In our series, both CISH and p16(INK4a)/Ki67 dual stain demonstrated high grade of performances. In particular, CISH would help to distinguish episomal from integrated HPV, in order to allow conclusions regarding the prognosis of the lesion, while p16(INK4a)/Ki67 dual stain approach would confer a high level of standardization to the diagnostic procedure.

Immunostaining of p16(INK4a)/Ki-67 and L1 capsid protein on liquid-based cytology specimens obtained from ASC-H and LSIL-H cases.

BACKGROUND: Atypical squamous cell cannot exclude high-grade squamous intraepithelial lesion (ASC-H) and low-grade intraepithelial lesion cannot exclude high-grade squamous intraepithelial lesion (LSIL-H) are ambiguous diagnostic entities for the prediction of high-grade cervical lesion. Objective and reproducible tests for predicting high-grade cervical lesions are needed to reduce unnecessary colposcopic referrals or follow-ups. OBJECTIVE: We aimed to identify an adequate set of adjunctive markers to predict cervical intraepithelial neoplasia grade 2+ (CIN2+) in residual liquid-based cytology specimens (LBCS). METHODS: We conducted p16 (INK4a)/Ki-67 and L1 capsid protein immunostaining and human papillomavirus (HPV) DNA typing on 56 LBCS diagnosed with ASC-H or LSIL-H, all of which were subjected to histologic confirmation or follow-up cytologic examination. RESULTS: Positivity for p16 (INK4a)/Ki-67 was associated with a histology of CIN2+ (P=0.047) and CIN3+ (P=0.002). Negativity for L1 capsid protein was associated with CIN2+ confirmed at follow-up (P=0.02).Positivity for high-risk HPV (HR-HPV) was associated with CIN2+ confirmed at follow-up (P=0.036) and a histology of CIN2+ (P=0.037). The sensitivity, specificity, positive predictive value, and negative predictive value for predicting follow-up CIN2+ were 76.2%, 51.4%, 48.5%, and 78.3%, respectively, for p16 (INK4a)/Ki-67 immunostaining; 95.2%, 34.3%, 46.5%, and 92.3%, respectively, for L1 capsid protein; and 66.7%, 67.7%, 54.5%, and 77.8%, respectively, for HR-HPV. The classification and regression tree analysis showed that the combined results of p16 (INK4a)/Ki-67 andL1 capsid protein immunostaining and the HR-HPV test, conducted sequentially, correctly classified 81.8% of samples (27/33)in the prediction of a histology of CIN2 + in ASC-H or LSIL-H. For determination of the histology of cervical intraepithelial neoplasia grade 3+ (CIN3+)in ASC-H or LSIL-H, we found that the combined results of p16 (INK4a)/Ki-67 and L1 capsid protein immunostaining correctly classified 78.8% (26/33) of samples. CONCLUSIONS: p16(INK4a)/Ki-67 and L1 capsid protein immunostaining and HR-HPV testing of residual LBCS diagnosed with ASC-H or LSIL-H are useful objective biomarkers for predicting CIN2+. Immunostaining for p16(INK4a)/Ki-67 and L1 capsid protein are sufficient to predict CIN3+.

A novel bisulfite-microfluidic temperature gradient capillary electrophoresis platform for highly sensitive detection of gene promoter methylation.

The hypermethylated tumor suppressor gene promoters are widely recognized as promising markers for cancer screening and ideal targets for cancer therapy, however, a major obstacle in their clinical study is highly sensitive screening. To address this limitation, we developed a novel bisulfite-microfluidic temperature gradient capillary electrophoresis (bisulfite-µTGCE) platform for gene methylation analysis by combining bisulfite treatment and slantwise radiative heating system-based µTGCE. Bisulfite-treated genomic DNA (gDNA) was amplified with universal primers for both methylated and unmethylated sequences, and introduced into glass microfluidic chip to perform electrophorectic separation under a continuous temperature gradient based on the formation of heteroduplexes. Eight CDKN2A promoter model fragments with different number and location of methylation sites were prepared and successfully analyzed according to their electrophoretic peak patterns, with high stability, picoliter-scale sample consumption, and significantly increased detection speed. The bisulfite-µTGCE could detect methylated gDNA with a detection limit of 7.5pg, and could distinguish as low as 0.1% methylation level in CDKN2A in an unmethylated background. Detection of seven colorectal cancer (CRC) cell lines with known and unknown methylation statuses of CDKN2A promoter and 20 tumor tissues derived from CRC patients demonstrated the capability of detecting hypermethylation in real-world samples. The wider adaptation of this platform was further supported by the detection of the CDKN2A and MLH1 promoters' methylation statuses in combination. This highly sensitive, fast, and low-consumption platform for methylation detection shows great potential for future clinical applications.

Codon optimization of MTS1 and its expression in Escherichia coli.

MTS1, which encodes a protein named p16, is an important gene involved in tumorigenesis. To increase the expression of p16 in Escherichia coli, MTS1 was synthesized de novo by recursive PCR, with codons optimized towards E. coli. Studies indicate that N-terminal amino acids of p16 had negative impact on its expression in E. coli. The function of p16DeltaN8 is not affected by the absence of N-terminal eight amino acids, compared with p16. p16DeltaN8 was expressed in E. coli, which reached 22% of total cell proteins. Purified p16DeltaN8 (purity was 98%) was delivered into A875 (melanoma), MCF7 (breast cancer), and HeLa (cervical cancer) cells by lipofectin. Results show purified p16DeltaN8 remarkably inhibited the growth of A875 and MCF7 cells, whereas it had little effect on HeLa cells.

Identification and characterization of a baboon reovirus-specific nonstructural protein encoded by the bicistronic s4 genome segment.

All characterized orthoreoviruses encode a characteristic spike-like protein on their polycistronic S1 genome segments that mediates virus cell attachment. In the case of baboon reovirus (BRV), the polycistronic S-class genome segment corresponds to the smallest S4 segment. We recently determined that the 5'-proximal open reading frame (ORF) of the bicistronic S4 segment encodes a nonstructural protein responsible for virus-induced syncytium formation. Current analysis indicates that the p16 protein encoded by the 3'-proximal ORF of the BRV S4 genome segment shows no sequence similarity to any other protein encoded by the orthoreoviruses, including the well-characterized sigma1/sigmaC reovirus cell attachment protein. Results indicate that p16 is a BRV-specific nonstructural protein that is not required for virus infection in cell culture and is not involved in viral cell attachment. In conjunction with previous studies of the BRV S1, S2, and S3 genome segments, the current results indicate that, unlike all other orthoreoviruses, BRV does not encode a cell attachment protein in its S-class genome segments. Furthermore, cell binding and infectivity studies suggested BRV may not utilize a functional homolog of the prototypical reovirus sigma1/sigmaC cell receptor-binding protein to mediate endocytic uptake by cells.

Superimposed histologic and genetic mapping of chromosome 9 in progression of human urinary bladder neoplasia: implications for a genetic model of multistep urothelial carcinogenesis and early detection of urinary bladder cancer.

The evolution of alterations on chromosome 9, including the putative tumor suppressor genes mapped to the 9p21-22 region (the MTS genes), was studied in relation to the progression of human urinary bladder neoplasia by using whole organ superimposed histologic and genetic mapping in cystectomy specimens and was verified in urinary bladder tumors of various pathogenetic subsets with longterm follow-up. The applicability of chromosome 9 allelic losses as non-invasive markers of urothelial neoplasia was tested on voided urine and/or bladder washings of patients with urinary bladder cancer. Although sequential multiple hits in the MTS locus were documented in the development of intraurothelial precursor lesions, the MTS genes do not seem to represent a major target for p21-23 deletions in bladder cancer. Two additional tumor suppressor genes involved in bladder neoplasia located distally and proximally to the MTS locus within p22-23 and p11-13 regions respectively were identified. Several distinct putative tumor suppressor gene loci within the q12-13, q21-22, and q34 regions were identified on the q arm. In particular, the pericentromeric q12-13 area may contain the critical tumor suppressor gene or genes for the development of early urothelial neoplasia. Allelic losses of chromosome 9 were associated with expansion of the abnormal urothelial clone which frequently involved large areas of urinary bladder mucosa. These losses could be found in a high proportion of urothelial tumors and in voided urine or bladder washing samples of nearly all patients with urinary bladder carcinoma.

Level of retinoblastoma protein expression correlates with p16 (MTS-1/INK4A/CDKN2) status in bladder cancer.

Recent studies have shown that patients whose bladder cancer exhibit overexpression of RB protein as measured by immunohistochemical analysis do equally poorly as those with loss of RB function. We hypothesized that loss of p16 protein function could be related to RB overexpression, since p16 can induce transcriptional downregulation of RB and its loss may lead to aberrant RB regulation. Conversely, loss of RB function has been associated with high p16 protein expression in several other tumor types. In the present study RB negative bladder tumors also exhibited strong nuclear p16 staining while each tumor with strong, homogeneous RB nuclear staining were p16 negative, supporting our hypothesis. To expand on these immunohistochemical studies additional cases were selected in which the status of the p16 encoding gene had been determined at the molecular level. Absent p16 and high RB protein expression was found in the tumors having loss of heterozygosity within 9p21 and a structural change (mutation or deletion) of the remaining p16 encoding gene allele, confirming the staining results. These results strongly support the hypothesis that the RB nuclear overexpression recently associated with poor prognosis in bladder cancer is also associated with loss of p16 function and implies that loss of p16 function could be equally deleterious as RB loss in bladder and likely other cancers.