The potential impact of prophylactic human papillomavirus vaccination on oropharyngeal cancer

The incidence of oropharyngeal cancer (OPC) is significantly increasing in the United States. Given that these epidemiologic trends are driven by human papillomavirus (HPV), the potential impact of prophylactic HPV vaccines on the prevention of OPC is of interest. The primary evidence supporting the approval of current prophylactic HPV vaccines is from large phase 3 clinical trials focused on the prevention of genital disease (cervical and anal cancer, as well as genital warts). These trials reported vaccine efficacy rates of 89% to 98% for the prevention of both premalignant lesions and persistent genital infections. However, these trials were designed before the etiologic relationship between HPV and OPC was established. There are differences in the epidemiology of oral and genital HPV infection, such as differences in age and sex distributions, which suggest that the vaccine efficacy observed in genital cancers may not be directly translatable to the cancers of the oropharynx. Evaluation of vaccine efficacy is challenging in the oropharynx because no premalignant lesion analogous to cervical intraepithelial neoplasia in cervical cancer has yet been identified. To truly investigate the efficacy of these vaccines in the oropharynx, additional clinical trials with feasible endpoints are needed. Cancer 2016;122:2313–2323 . © 2016 American Cancer Society.     

HPV16 increases the number of migratory cancer stem cells and modulates their miRNA expression profile in oropharyngeal cancer

Human papillomavirus type 16 (HPV16) is a major risk for development of oropharyngeal squamous‐cell‐carcinoma (OPSCC). Although HPV⁺ OPSCC metastasize faster than HPV^? tumors, they have a better prognosis. The molecular and cellular alterations underlying this pathobiology of HPV⁺ OPSCC remain elusive. In this study, we examined whether expression of HPV16‐E6E7 targets the number of migratory and stationary cancer stem cells (CSC). Furthermore, we wanted to elucidate if aberrantly expressed miRNAs in migratory CSC may be responsible for progression of OPSCCs and whether they may serve as potential novel biomarkers for increased potential of metastasis. Our studies revealed that HPV16‐E6E7 expression leads to an increase in the number of stationary (CD44^high/EpCAM^high) stem cells in primary keratinocyte cultures. Most importantly, expression of E6E7 in the cell line H357 increased the migratory (CD44^high/EpCAM^low) CSC pool. This increase in migratory CSCs could also be confirmed in HPV⁺ OPSCC. Differentially expressed miRNAs from HPV16‐E6E7 positive CD44^high/EpCAM^low CSCs were validated by RT‐qPCR and in situ hybridization on HPV16⁺ OPSCCs. These experiments led to the identification of miR‐3194‐5p, which is upregulated in primary HPV16⁺ OPSCC and matched metastasis. MiR‐1281 was also found to be highly expressed in HPV⁺ and HPV^? metastasis. As inhibition of this miRNA led to a markedly reduction of CD44^high/EpCAM^low cells, it may prove to be a promising drug target. Taken together, our findings highlight the capability of HPV16 to modify the phenotype of infected stem cells and that miR‐1281 and miR3194‐5p may represent promising targets to block metastatic spread of OPSCC.     

Multiple imputation and clinico-serological models to predict human papillomavirus status in oropharyngeal carcinoma: An alternative when tissue is unavailable

In cancer epidemiological studies, determination of human papillomavirus (HPV) in oropharyngeal squamous cell carcinoma (OPSCC) typically depends on the availability of tumor tissue testing, and/or tumor tissue access. Identifying alternative methods for estimating HPV status can improve the quality of such studies when tissue is unavailable. We developed multiple predictive models for tumor HPV status and prognosis by combining both clinico-epidemiological variables and either serological multiplex assays of HPV or multiple imputation of HPV status (HPV_mi). Sensitivity, specificity and accuracy of these methods compared to either p16 immunostaining (p16 IHC) or survival were assessed. When compared to a reference of tumor tissue p16 IHC in 783 OPSCC patients, the clinic-HPV_sero model incorporating a composite of 20 HPV serological antibodies (HPV_sero) and 4 clinical factors (c-index: 0.96) performed better than using HPV_sero (c-index: 0.92) or HPV_mi (c-index: 0.76) alone. However, the model that contained a single HPV16 E6 antibody combined with four clinical variables, performed extremely well (clinic-s1-16E6; c-index: 0.95). When defining HPV status by HPV_sero, s1-16E6, HPV_mi or through p16 IHC, each of these definitions demonstrated improved overall and disease-free survival in HPV-positive OPSCC patients, when compared to HPV-negative patients (adjusted hazard ratios between 0.25 and 0.63). Our study demonstrates that when blood samples are available, a model that utilizes a single s1-16E6 antibody combined with several clinical features has excellent test performance characteristics to estimate HPV status and prognosis. When neither blood nor tumor tissue is available, multiple imputation, calibrated on local population characteristics, remains a viable, but suboptimal option.     

宫颈癌及其癌前病变组织中HPV16 E6、HPV16 E7蛋白的表达及其意义

目的 探讨宫颈癌及其癌前病变组织中HPV16E6、E7蛋白的表达及其意义。方法 采用免疫组化SP法对15例正常宫颈、25例宫颈上皮内瘤变（C1N）以及61例浸润性宫颈癌组织进行了HPVl6E6、HPVl6E7蛋白表达的检测。结果在正常宫颈、CINI～Ⅱ、CINⅢ及浸润性宫颈癌中，HPVl6E6蛋白的阳性表达率分别为0（0／15）、7．14％（1／14）、36．36％（4／11）、59．02％（36／61）；CINⅢ和浸润性宫颈癌中HPVl6E6蛋白阳性表达率明显高于正常宫颈组织和CINI～Ⅱ（P〈0．05）；在高、中、低分化宫颈癌中，HPVl6E6蛋白阳性表达率分别为45．45％（5／11）、77．78％（14／18）、53．13％（17／32）；HPVl6E6蛋白在不同分化程度的宫颈癌组织中的阳性表达率有显著性差异（P〈0．05），但HPVl6E6蛋白表达与官颈癌组织分化程度无明显相关性（ys=0．123），HPVl6E6蛋白阳性表达率与宫颈癌临床分期和淋巴结转移无关（P〉0．05）。HPVl6E7蛋白在正常宫颈上皮、CINI-Ⅱ、CIN Ⅲ及浸润性富颈癌组织中的阳性表达率分别为20．00％（3／15）、42．86％（6／14）、63．64％（7／11）、57．38％（35／61），HPVl6E7蛋白在不同宫颈组织中的阳性表达率无明显差异（P=0．05）；HPVl6E7蛋白的表达与富颈癌临床分期、淋巴结转移和组织分化均无关（P〉0．05）。结论 HPVl6E6蛋白的检测有可能作为宫颈癌前病变转归的指标。     

HPV相关性口咽癌诊治现状及研究进展

人乳头瘤病毒(human papillomavirus,HPV)感染可引起多种疾病,其中高危型人乳头瘤病毒与头颈部鳞状细胞癌及宫颈癌关系更加密切.近年来,大量研究表明口咽癌的发病率呈现逐年上升的趋势,其中又以HPV感染所造成的HPV相关性口咽鳞状细胞癌(oropharyngeal squamous cell carci...     

Diagnostic accuracy of p16INK4a immunohistochemistry in oropharyngeal squamous cell carcinomas: A systematic review and meta‐analysis

The accurate diagnosis of human papillomavirus (HPV) causality in oropharyngeal squamous cell carcinomas (OPSCC) is likely to influence therapeutic decisions in affected patients in the near future. We conducted a systematic review and meta‐analysis to determine the diagnostic accuracy of p16^INK4a immunohistochemistry (IHC) to identify HPV‐induced OPSCC. We identified all studies that performed p16^INK4a IHC (index test) and HPV E6/E7 mRNA detection using an amplification‐based method (gold standard to indicate a transforming relevance of HPV) in OPSCC. Testing with one or more comparator tests (HPV DNA PCR, HPV DNA in situ hybridization (ISH) and p16^INK4a IHC/HPV DNA PCR combined testing) was an optional criterion for inclusion. Among 1,636 retrieved studies 24 fulfilled the inclusion criteria. The pooled sensitivity of p16^INK4a IHC, HPV DNA PCR, HPV DNA ISH and p16^INK4a IHC/HPV DNA PCR combined testing was 94% (95%‐confidence interval (CI) 91–97%), 98% (CI 94–100%), 85% (CI 76–92%) and 93% (CI 87–97%), respectively. The pooled specificity was 83% (CI 78–88%), 84% (CI 74–92%), 88% (CI 78–96%) and 96% (CI 89–100%), respectively. p16^INK4a IHC/HPV DNA PCR combined testing was as sensitive as either p16^INK4a IHC or HPV DNA PCR alone but significantly more specific than either separate test. In conclusion, p16^INK4a IHC is highly sensitive but moderately specific to diagnose HPV‐transformed OPSCC when used as a single test. Combined p16^INK4a IHC and HPV DNA PCR testing significantly enhances specificity while maintaining high sensitivity. This diagnostic test combination thus represents an attractive testing strategy for the reliable diagnosis of HPV‐induced OPSCC in the clinical setting and may constitute an inclusion criterion for future therapeutic trials.     

HPV16型E6、E7变异与宫颈癌发生发展的研究进展

宫颈癌是全球15 ～44岁女性中第二常见的恶性肿瘤,每年的死亡人数约为265 653人,在中国,宫颈癌的发生率及死亡率仍较高.高危型人乳头状瘤病毒(HPV)持续感染是宫颈癌前病变及宫颈癌发生的必要条件,HPV16是最常见的高危人乳头瘤病毒.HPV16编码的E6和E7蛋白在HPV相关的肿瘤中起关键作用.近年来的研究揭示了HPV16 E6、E7基因的变异引起氨基酸变化可影响E6、E7蛋白与p53、pRb 的结合,进而与宿主细胞恶性转化相关.本文将对近年来HPV16 E6、E7变异在宫颈癌发生发展中的作用作一综述.     

HPV16 E6蛋白与hDaxx的相互作用及其对HeLa细胞凋亡的影响

Objective: To study the interaction of human papillomavirus type 16 (HPV16 E6) protein and human death domain associated protein (hDaxx) and its effect on apoptosis of HeLa cells to provide the experimental basis for exploring the oncogenic mechanism of HPV16 E6 protein. Methods: Recombinant vector of pGADT7/E6 or pGBKT7/hDaxx was con- structed. The interaction of E6 protein and hDaxx was detected by yeast two-hybrid system. Their expression in yeast was detected by Western blotting. The eukaryotic plasmids of E6 and hDaxx were co-transfected into HeLa cells. Apoptosis was induced by 5-FU. The apoptotic rate was measured by flow cytometry (FCM). Results: E6 protein had intracellular interaction with hDaxx. The apoptotic rate was rising with the increase in the transfection quantity of pcDNA3.1 (-) / hDaxx in pcDNA3.1 (-) /E6 and pcDNA3.1 (-) / hDaxx co-transfected cells. The difference was significant ( P < 0. 01). Conclusion: There is intracellular interaction between HPV16 E6 protein and hDaxx. The over-expression of hDaxx can increase the sensitivity of E6 protein positive HeLa cells to 5-FU. The effect was in a dose dependent manner. HPV16 E6 protein inhibited the apoptosis of HeLa cells by interacting with hDaxx.     

Risk factors and survival by HPV‐16 E6 and E7 antibody status in human papillomavirus positive head and neck cancer

High‐risk human papillomavirus types (HPV‐HR) are associated with head and neck cancer (HNC) risk and better survival. Most patients with HPV‐HR DNA‐positive tumors develop anti‐HPV E6/E7 antibodies; however, it is unclear whether those who mount an immune response have similar risk factors or clinical outcomes as those who do not. HPV‐16 DNA tumor‐positive HNC cases were evaluated for HPV‐16 E6 and E7 antibodies using a GST capture ELISA system. Among 57 HPV‐16 DNA tumor‐positive HNC cases, 67% were detected with HPV‐16 E6 and/or E7 antibodies. Male gender (76% vs. 42%, p = 0.02), younger age (63% vs. 16%, p = 0.001) but not tobacco or alcohol were associated with E6 and/or E7 seropositivity. Seropositivity was associated more often with late stage (76%), poor grade (65%), positive nodes (82%). and in the oropharynx (82%), Median disease‐specific and recurrence‐free survival were longer in E6 and/or E7 seropositive compared to E6/E7‐negative cases (2.2 years vs. 1.4 years, both outcomes), although results were not statistically significant. When examined jointly with p16 expression, E6 and/or E7‐positive/p16‐positive cases had better disease‐specific (2.1 years vs. 1.1 years, p = 0.06) and recurrence‐free (2.3 years vs. 1.1 years, p = 0.03) survival compared to E6‐/E7‐/p16‐ cases. These findings suggest there are 2 distinct HNC patient groups with HPV DNA‐positive tumors, distinguishable by E6 and/or E7 antibody status. Differences in antibody status are associated with distinct risk factors and clinical outcomes. This information can be available as a simple blood test at initial presentation, before the removal of tissue through biopsy or surgery.     

Up‐regulation of interleukin‐17 expression by human papillomavirus type 16 E6 in nonsmall cell lung cancer

BACKGROUND:

Human papillomavirus (HPV) 16/18 infection is associated with nonsmoking lung cancer. In this study, the authors investigated a putative correlation between interleukin (IL)‐17 expression and HPV infection in clinical nonsmall cell lung cancer (NSCLC) tissues and examined the effects of HPV infection on a human NSCLC cell line.

METHODS:

IL‐17 expression was investigated in 79 NSCLC tumor tissues by immunohistochemistry. Growth rate, IL‐17 mRNA, and secreting protein levels were also examined in HPV 16/18 E6‐transfected H1299 human NSCLC cells.

RESULTS:

Immunohistochemical data showed that 48.1% of lung tumors had IL‐17 staining, which was significantly associated with patients' sex (P = .03), HPV infection (P = .002), and tumor stage (P = .03). Significant correlations of IL‐17 with IL‐6 (P < .001) and IL‐17 with Mcl‐1 (P < .001) expression were also observed. Cell growth rate was increased, and IL‐17/Mcl‐1 expression levels were elevated in HPV 16 E6‐transfected H1299 cells. The transfected E6 oncoproteins can significantly up‐regulate expression levels of IL‐17 and antiapoptotic protein Mcl‐1.

CONCLUSIONS:

The study suggests that HPV infection‐induced IL‐17 levels can stimulate Mcl‐1 expression through the PI3K pathway and promote lung tumor cell progression through a p53‐ and IL‐6‐independent pathway. Cancer 2010. © 2010 American Cancer Society.