Human papillomavirus infection in head and neck cancer: the role of the secretory leukocyte protease inhibitor

Secretory leukocyte protease inhibitor (SLPI) in cancer pathophysiology: Mechanisms of action and clinical implications

Cancer is a multifaceted disorder frequently linked to the dysregulation of several biological processes. The SLPI is a multifunctional protein involved in the modulation of immunological response and the inhibition of protease activities. SLPI acts as an inhibitor of proteases, exerts antibacterial properties, and suppresses the transcription of proinflammatory genes through the nuclear factor-kappa B (NF-κB) pathway. The role of this protein as a regulatory agent has been implicated in various types of cancer. Recent research has revealed that SLPI upregulation in cancer cells enhances the metastatic capacity of epithelial malignancies, indicating the deleterious effects of this protein. Furthermore, SLPI interacts intricately with other cancer-promoting factors, including matrix metalloproteinase-2 (MMP-2), MMP-9, the NF-κB and Akt pathways, and the p53-upregulated modulator of apoptosis (PUMA). This review provides an overview of the role of SLPI in cancer pathophysiology, emphasizing its expression in cancer cells and tissues, its potential as a prognostic biomarker, and its therapeutic promise as a target in cancer treatment. The mechanisms of SLPI action in cancer, including its anti-inflammatory effects, regulation of cell proliferation and angiogenesis, and modulation of the tumor microenvironment, have been investigated. The clinical implications of SLPI in cancer have been discussed, including its potential as a diagnostic and prognostic biomarker, its role in chemoresistance, and its therapeutic potential in several types of cancer, such as hepatocellular carcinoma (HCC), colorectal cancer (CRC), pancreatic cancer, head and neck squamous cell carcinoma (HNSCC), ovarian cancer (OvCa), prostate cancer (PC), gastric cancer (GC), breast cancer, and other cancers. In addition, we emphasized the significance of SLPI in cancer, which offers fresh perspectives on potential targets for cancer therapy.

Does human papillomavirus modify the risk of oropharyngeal cancer related to smoking and alcohol drinking? A systematic review and meta‐analysis

Objective

To synthesize evidence for interactions of traditional oropharyngeal squamous cell carcinoma (OPSCC) risk factors—tobacco smoking and alcohol drinking—with human papillomavirus (HPV).

Data Sources

MEDLINE, Embase, Cochrane Database of Systematic Reviews, ProQuest, and Global Health were searched with no restrictions on language or publication date.

Methods

All case–control studies assessing interactions between these factors in OPSCC were considered. Quality was assessed using the Newcastle‐Ottawa Scale for case–control studies. The main outcome was the OR for developing OPSCC for the following interactions: (1) HPV and smoking, (2) HPV and alcohol drinking, and (3) HPV, alcohol drinking, and smoking. Interactions were assessed from stratified analysis (by HPV status) and/or joint effect analysis (synergy index and multiplicative index).

Results

The search provided 3084 relevant studies, of which 9 were included. In the stratified analysis, the OR of developing OPSCC among smokers with HPV was less than that among smokers without HPV. A similar pattern was observed for alcohol drinking. This effect persisted among smokers and heavy alcohol drinkers with HPV compared with those without HPV. Joint effect analysis on the additive scale showed sub‐additive antagonistic interactions between HPV and smoking, and between HPV and alcohol. On the multiplicative scale, sub‐multiplicative interactions were found between HPV and smoking, and HPV and alcohol.

Conclusions

This meta‐analysis suggests a negative directed interaction of HPV and smoking; and HPV and heavy alcohol drinking in the development of primary OPSCC on stratified analysis and joint effect analysis.

Level of Evidence

3A.

SLPI suppresses hepatocellular carcinoma progression via endoplasmic reticulum stress induced apoptosis

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. Secretory leukocyte protease inhibitor (SLPI) has been reported to function as a regulatory factor in several cancers. However, its biological functions and underlying mechanisms in HCC remain to be uncovered. Here, we aimed to explore the effect of SLPI in HCC. In our study, we found that the mRNA and protein expression levels of SLPI were significantly down-regulated in HCC tissues and hepatoma cell lines and low level of SLPI predicted worse survival in our HCC cohorts. In term of function, silencing of SLPI markedly promoted whereas overexpression SLPI suppressed proliferation, migration and invasion capabilities of HCC cells in vitro, and ectopic expression of SLPI inhibited the tumorigenicity of HCC cells in vivo. Mechanistic studies demonstrated that SLPI played a protective role in HCC progression via activating endoplasmic reticulum stress (ER stress)-mediated apoptosis of hepatoma cells, which could be regulated by MAPK signaling pathways. In summary, our findings highlight that SLPI could serve as a potential prognostic biomarker and putative tumor suppressor by enhancing ER stress-induced apoptosis in HCC cells mediated by MAPK signaling pathways, which provides new insights into promising therapeutic targets for HCC treatment.

The vaginal microbiota and innate immunity after local excisional treatment for cervical intraepithelial neoplasia

BACKGROUND

Vaginal microbiota (VMB) composition is altered in women with cervical intra-epithelial neoplasia (CIN) compared to healthy controls and is associated with disease progression. However, the impact of CIN excision on the VMB and innate immunity is not known. This observational study aims to explore the impact of CIN excision on the VMB, antimicrobial peptides (AMP) and proinflammatory cytokines.

METHODS

We sampled 103 non-pregnant, premenopausal women at the time of excisional treatment for CIN and at their 6-month follow-up visit. A further 39 untreated controls with normal cytology were also sampled. We used metataxonomics to group vaginal swab samples into community state types (CSTs) and ELISA to quantify cytokine and AMP levels in matched vaginal secretions. Analyses were performed to compare the bacterial composition and immune analyte levels before and after CIN excision and in healthy controls.

RESULTS

Women with CIN had significantly higher rates of Lactobacillus species depletion pre-treatment compared to healthy controls (CST IV 21/103, 20% vs 1/39, 3%, p = 0.0081). Excision did not change the VMB composition, with CST IV remaining significantly more prevalent after excision compared to untreated, healthy controls (CST IV 19/103, 20% vs 1/39, 3%, p = 0.0142). Prevotella bivia and Sneathia amnii were significantly higher in samples before treatment compared to untreated controls, and Prevotella bivia remained significantly higher amongst the treated, with less Lactobacillus crispatus compared to untreated controls. IL-1β and IL-8 remained significantly elevated pre- (p < 0.0001 and p = 0.0014, respectively) and post-treatment (p < 0.0001 and p = 0.0035, respectively) compared to untreated controls. Levels of human beta-defensin-1 and secretory leukocyte protease inhibitor were both significantly reduced following CIN excision (p < 0.0001); however, their levels remained lower than controls post-treatment.

CONCLUSIONS

Women with CIN have an increased prevalence of Lactobacillus sp. depletion, high-diversity VMB composition, and higher levels of proinflammatory cytokines and AMPs compared to normal controls. Surgical excision of the disease reduces levels of vaginal AMPs but does not alter VMB composition or cytokine levels. These findings suggest that women with CIN have an inherent predisposition to a high-diversity proinflammatory environment that is not corrected by disease excision. The failure to re-establish a Lactobacillus-enriched CST may explain why women remain at high risk of pre-invasive and invasive disease recurrence.

Oral secretory leukocyte protease inhibitor (SLPI): Associations with oropharyngeal cancer and treatment outcome

BACKGROUND

Rates of oropharyngeal cancer (OPC) associated with alcohol & tobacco use have decreased, while human papillomavirus (HPV) associated OPC has increased among men in the US. Secretory leukocyte protease inhibitor (SLPI), detectable in a variety of secretions, has been implicated in cancers of the head and neck, associated with tumor progression and anti-viral activity. Using the recently verified oral gargle specimen, this study aimed to assess the association of salivary SLPI expression with risk of OPC and response to treatment.

METHODS

A case-control study design compared levels of salivary SLPI among OPC cases to age and tobacco smoking matched healthy controls. Oral HPV DNA and SLPI was quantified from oral gargle specimens. Logistic regression estimated odds ratios (OR) and 95% confidence intervals (CI) for associations of oral SLPI and risk of OPC and treatment outcomes.

RESULTS

In crude and adjusted analyses of 96 OPC cases and 97 age- and smoking-matched controls, OPC was not significantly associated with oral gargle SLPI levels. Among cases, oral SLPI was associated with tonsillectomy (p = 0.018) and among controls oral SLPI was associated with HPV in the oral gargle (p = 0.008). Higher concentrations of SLPI was significantly associated with increased odds of incomplete treatment response (T2: OR: 12.39; 95% CI: 1.44-106.72; T3: OR: 9.86; 95% CI: 1.13-85.90) among all cases, but not among P16+ cases.

CONCLUSIONS

Salivary SLPI was not associated with OPC risk but was associated with higher odds of an incomplete treatment response.

Relevance of Human Papillomaviruses in Head and Neck Cancer-What Remains in 2021 from a Clinician's Point of View?

Human papillomaviruses (HPV) cause a subset of head and neck cancers (HNSCC). HPV16 predominantly signs responsible for approximately 10% of all HNSCC and over 50% of tonsillar (T)SCCs. Prevalence rates depend on several factors, such as the geographical region where patients live, possibly due to different social and sexual habits. Smoking plays an important role, with non-smoking patients being mostly HPV-positive and smokers being mostly HPV-negative. This is of unparalleled clinical relevance, as the outcome of (non-smoking) HPV-positive patients is significantly better, albeit with standard and not with de-escalated therapies. The results of the first prospective de-escalation studies have dampened hopes that similar superior survival can be achieved with de-escalated therapy. In this context, it is important to note that the inclusion of p16^INK4A (a surrogate marker for HPV-positivity) in the 8th TMN-classification has only prognostic, not therapeutic, intent. To avoid misclassification, highest precision in determining HPV-status is of utmost importance. Whenever possible, PCR-based methods, still referred to as the "gold standard”, should be used. New diagnostic antibodies represent some hope, e.g., to detect primaries and recurrences early. Prophylactic HPV vaccination should lead to a decline in HPV-driven HNSCC as well. This review discusses the above aspects in detail.

Overexpression of secretory leukocyte peptidase inhibitor (SLPI) does not modulate experimental osteoarthritis but may be a biomarker for the disease

OBJECTIVE

Osteoarthritic cartilage destruction can be regulated by the balance between proteases and anti-proteases. Here, we sought to identify novel cellular protease inhibitors associated with osteoarthritis (OA) pathogenesis.

METHODS

Candidate molecules were screened from microarray data of chondrocytes treated with OA-associated catabolic factors. The functions of candidate molecules in OA pathogenesis were examined in primary-culture mouse articular chondrocytes and mouse models of OA, such as those stimulated by destabilization of the medial meniscus (DMM) or intra-articular (IA) injection of adenovirus expressing the candidate gene. The value of the selected candidate molecule as a biomarker of OA was examined by measuring its circulating levels in human and mouse blood.

RESULTS

Bioinformatic analysis identified secretory leukocyte peptidase inhibitor (SLPI) as a highly upregulated cellular protease inhibitor in chondrocytes treated with pathogenic catabolic factors, including interleukin (IL)-1β, hypoxia-inducible factor (HIF)-2α, and zinc importer ZIP8. The adenovirus-mediated overexpression of SLPI in joint tissues did not cause any OA-like change or modulate DMM- or HIF-2α-induced experimental OA in mice. SLPI also did not markedly modulate the expression of OA-associated catabolic or anabolic factors in chondrocytes. However, SLPI was specifically upregulated in OA cartilage, and the serum SLPI levels were significantly elevated in human OA patients and experimental OA mice, suggesting that SLPI may be a biomarker of OA.

CONCLUSION

Although SLPI is upregulated in OA chondrocytes, it does not appear to per se modulate OA development in mice. However, it may be a potential biomarker of OA in humans and animal models.

Secretory Leukocyte Protease Inhibitor (SLPI) in mucosal tissues: Protects against inflammation, but promotes cancer

The immune system is continuously challenged with large quantities of exogenous antigens at the barriers between the external environment and internal human tissues. Antimicrobial activity is essential at these sites, though the immune responses must be tightly regulated to prevent tissue destruction by inflammation. Secretory Leukocyte Protease Inhibitor (SLPI) is an evolutionarily conserved, pleiotropic protein expressed at mucosal surfaces, mainly by epithelial cells. SLPI inhibits proteases, exerts antimicrobial activity and inhibits nuclear factor-kappa B (NF-κB)-mediated inflammatory gene transcription. SLPI maintains homeostasis at barrier tissues by preventing tissue destruction and regulating the threshold of inflammatory immune responses, while protecting the host from infection. However, excessive expression of SLPI in cancer cells may have detrimental consequences, as recent studies demonstrate that overexpression of SLPI increases the metastatic potential of epithelial tumors. Here, we review the varied functions of SLPI in the respiratory tract, skin, gastrointestinal tract and genitourinary tract, and then discuss the mechanisms by which SLPI may contribute to cancer.

The interaction of smoking habit, SLPI and AnxA2 in HPV associated head and neck and other cancers

Six own studies confirm a correlation between smoking, expression of the secretory leukocyte protease inhibitor (SLPI, an antileukoproteinase) and expression of Annexin A2 (AnxA2), and their influence on human papilloma virus (HPV)-infections. SLPI and HPV are ligands of AnxA2. This correlation was tested on 928 tissue samples from 892 patients in six independent studies [squamous cell carcinoma of the head and neck (HNSCC), n = 522; non-neoplastic tonsils n = 214; clinically normal mucosa, n = 93 (of these n = 57 were obtained from patients treated for non-malignant diseases and n = 36 were obtained from HNSCC-patients) and vulvar squamous cell carcinoma (VSCC) n = 99]. HPV-DNA-status was determined by GP5+/GP6+-PCR, followed in case of HPV-positivity by Sanger sequencing and RT-PCR using HPV-type specific primers. SLPI- and AnxA2-gene-expression was determined by RT-q-PCR; SLPI-protein-expression was additionally determined by immunohistochemistry (IHC); the data were correlated with each other and with patient characteristics. Smoking results in increased SLPI-gene- and protein- and AnxA2-gene-expression with significantly higher SLPI- than AnxA2-gene-expression. SLPI is decreased in non-smokers with a continuous AnxA2-surplus. HPV-status correlates with smoking habit, with smokers being mostly HPV-negative and non-smokers HPV-positive. We hypothesize that smoking leads to SLPI-overexpression with SLPI-binding to AnxA2. Thus, HPV cannot bind to AnxA2 but this seems pivotal for HPV-cell-entry. Smoking favors SLPI-expression resulting in HPV-negative carcinomas, while HPV-positive carcinomas are more common in non-smokers possibly due to a surplus of unbound AnxA2. In addition, the hypothesis may contribute to understand why smokers show increased oral HPV-prevalence in natural history studies but do not necessarily develop HPV-associated lesions.

Joint effect of tobacco, alcohol, and oral HPV infection on head and neck cancer risk in the French West Indies

We investigated the role of tobacco and alcohol consumption on the occurrence of head and neck squamous cell carcinomas (HNSCC), and the joint effects of these factors with oral human papillomavirus (HPV) infection in the French West Indies, in the Caribbean. We conducted a population‐based case‐control study (145 cases and 405 controls). We used logistic regression models to estimate adjusted odds ratios (OR) and their 95% confidence intervals (CI). Two‐way interactions were assessed on both multiplicative and additive scales. Current smoking (OR = 11.6, 95% CI = 6.7‐20.1), drinking more than five glasses of alcohol per day (OR = 2.7, 95% CI = 1.2‐4.7), and oral infection with High‐risk HPV (OR = 2.4, 95% CI = 1.1‐5.0) were significantly associated with HNSCC. The combined exposure to tobacco and alcohol produced a significant synergistic effect on the incidence of HNSCC. Oral infection with High‐risk HPV increased the risk of HNSCC in never smokers and nondrinkers. The effects of tobacco, alcohol, and of the combined exposure of tobacco and alcohol were substantially lower in HPV‐positive than in HPV‐negative HNSCC. This is the first case‐control study to investigate the role of tobacco smoking, alcohol drinking and oral HPV infection in an Afro‐Caribbean population. Although each of these risk factors has a significant effect, our findings indicate that tobacco and alcohol play a less important role in Hr‐HPV‐positive HNSCC. Further investigations are warranted notably on the interaction of these three risk factors by cancer site.

Secretory Leukocyte Protease Inhibitor in Oral Potentially Malignant Disorders and Oral Squamous Cell Carcinoma

Objectives: Secretory leukocyte protease inhibitor (SLPI) is a protein found in body fluids and implicated as a prognostic factor in many cancers. There is limited research regarding serum and salivary SLPI in oral potentially malignant disorders (OPMDs) and oral squamous cell carcinoma (OSCC). Materials and Methods: A total of 90 participants were included in the study; of which 30 formed the control group, 30 included participants with OPMD, and 30 included participants with OSCC. Serum and salivary levels of SLPI were estimated using enzyme-linked immunosorbent assay. Results: Serum levels of SLPI showed progressive increase in potentially malignant disorders and SCC patients when compared with controls, while salivary levels were increased in both OPMD and OSCC groups as compared to controls. However, the difference between groups was not statistically significant (P < 0.05). Conclusion: The above results suggest that increase in SLPI levels in the serum may have a role in indicating progression of OPMD to OSCC.

Secretory leukocyte protease inhibitor suppresses HPV E6-expressing HNSCC progression by mediating NF-κB and Akt pathways

Background

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide and human papillomavirus (HPV) has been increasingly recognized as a pathogenic factor for the initiation and development of HNSCC. E6 oncogene, an essential component of the HPV 16 virus, acts as a leading cause of the malignant transformation of cancer cells. Therefore, investigating the biological effect and potential mechanisms of E6 oncogene on HNSCC cells and exploring potential therapeutic methods is of great value.

Methods

MTT assay, cell cycle analysis, and apoptosis assay were implemented to detect the biological effect of E6 oncogene on the growth of HNSCC cells. Wound healing assay and transwell assay were used to evaluate the role of E6 in the migration and invasion of HNSCC cells. Western blot and immunofluorescence assay were adopted to explore the regulatory mechanisms underlying E6-induced HNSCC progression. Then, exogenous secretory leukocyte protease inhibitor (SLPI) was added into the cell culture to investigate whether it could maintain its tumor suppressor effect on E6-expressing HNSCC cells.

Results

HPV E6 oncogene could promote the proliferation, cell cycle period, apoptosis resistance, migration and invasion of HNSCC cells by activating NF-κB and Akt pathways. Immunohistochemical analysis conducted on HNSCC tissues illustrated that SLPI was further downregulated in HPV positive HNSCC compared to HNSCC without HPV infection. Exogenous SLPI significantly inhibited HPV E6-mediated malignant phenotypes in HNSCC cells by inhibiting the activation of NF-κB and Akt and signaling pathways.

Conclusions

This study demonstrated that E6 oncogene led to the malignant transformation of HNSCC cells by regulating multiple pathways. SLPI could reverse the effect of E6 oncogene on HNSCC, implying that the functional inhibition of E6 by SLPI may be exploited as an attractive therapeutic strategy.

Over Expressed TKTL1, CIP-2A, and B-MYB Proteins in Uterine Cervix Epithelium Scrapings as Potential Risk Predictive Biomarkers in HR-HPV-Infected LSIL/ASCUS Patients

High oncogenic risk human papillomaviruses (HR-HPVs) promote cervical carcinoma development, the fourth most common feminine cancer. A slow oncodevelopmental phase—defined histopathologically as Cervical Intraepithelial Neoplasia (CIN) grades 1–3, or cytologically as Low- or High-grade Squamous Intraepithelial Lesions (LSIL or HSIL)—precedes the malignancy. Cervical carcinoma screenings through HR-HPV genotyping and Pap smears are regularly performed in Western countries. Faulty cytology screening or genotyping or patients' non-compliance with follow-ups can let slip an oncoprogression diagnosis. Novel biomarker tests flanking HR-HPV genotyping and cytology could objectively predict the risk of disease progression thus helping triage LSIL/ASCUS patients. Here, anonymized leftovers of fresh cervical epithelium scrapings from twice (LSIL/ASCUS and HR-HPV DNA)-positive and twice (Pap smear- and HR-HPV DNA)-negative (control) patients in a proteome-preserving solution served to assess the biomarker worth of three cervical carcinoma-related proteins, i.e., B-MYB (or MYBL2), Cancerous Inhibitor of PP2A (CIP-2a), and transketolase-like1 (TKTL1). Leftovers anonymity was strictly kept and storage at −80°C, protein extraction, immunoblotting, and band densitometry were blindly performed. Only after tests completion, the anonymous yet code-corresponding HR-HPV-genotyping and cytology data allowed to assign each sample to the twice-positive or twice-negative group. Descriptive statistics showed that the three proteins levels significantly increased in the twice-positive vs. twice-negative scrapings. Diagnostic ROC curve analysis identified each protein's Optimal Decision Threshold (OTD) showing that TKTL1 and CIP-2a are stronger risk predictive biomarkers (Sensitivity, 0.91–0.93; Specificity, 0.77–0.83) than B-MYB. Logistic Regression coupled with Likelihood-Ratio Tests confirmed that a highly significant relation links increasing TKTL1/CIP-2a/B-MYB protein levels in twice-positive cervical scrapings to the risk of HR-HPV-driven oncoprogression. Finally, a 3 year clinical follow-up showed that 13 patients (50% of total) of the twice-positive group with biomarker values over OTDs compliantly underwent scheduled colposcopy and biopsy. Of these, 11 (i.e., 84.7%) received a positive histological diagnosis, i.e., CIN1 (n = 5; 38.5%) or CIN2/CIN2+ (n = 6; 46,2%). Therefore, TKTL1/CIP-2a/B-MYB protein levels could objectively predict oncoprogression risk in twice (HR-HPV- and Pap smear)-positive women. Further studies will assess the translatability of these findings into clinical settings.

Smoking-Induced SLPI Expression Hinders HPV Infections Also in Squamous Cell Carcinomas of the Vulva

In HNSCC, protein- and mRNA-expression of the antileukoproteinase SLPI are significantly inverse correlated with HPV-infection suggesting that elevated expression of SLPI protects against HPV-infections. Moreover, SLPI-expression is up-regulated in HNSCC-patients reporting a smoking habit. Here, we investigate the described correlation in other HPV-driven cancers, namely vulvar squamous cell carcinoma (VSCC). FFPE samples of 99 VSCC were analyzed by PCR for HPV-DNA-expression and by RT-qPCR for SLPI-mRNA-expression. Of 99 VSCC 10 (10.1%) are HPV-positive; 9 were HPV16; 1 HPV18; all were E6/E7 mRNA-positive. 33 of the 99 patients (33.3%) reported a smoking habit; 7 (21.1%) of these were HPV-positive. Of 66 (66.7%) non-smokers 3 (4.5%) were HPV-positive. SLPI-expression was 4.0-fold lower in HPV-positive than HPV-negative patients. Smoking resulted in 2.3-fold higher SLPI expression. The data presented here indicate that SLPI plays a pivotal role in HPV-infection not only in HNSCC but also in VSCC and possibly also in other HPV-driven cancers. This however, needs to be analyzed in future studies. Furthermore these data lead to the hypothesis that the smoking induced SLPI-increase is systemic rather than local, as assumed based on the HNSCC data.

Differential Effect of Smoking on Gene Expression in Head and Neck Cancer Patients

Smoking is a well-known behavior that has an important negative impact on human health, and is considered to be a significant factor related to the development and progression of head and neck squamous cell carcinomas (HNSCCs). Use of high-dimensional datasets to discern novel HNSCC driver genes related to smoking represents an important challenge. The Cancer Genome Atlas (TCGA) analysis was performed in three co-existing groups of HNSCC in order to assess whether gene expression landscape is affected by tobacco smoking, having quit, or non-smoking status. We identified a set of differentially expressed genes that discriminate between smokers and non-smokers or based on human papilloma virus (HPV)16 status, or the co-occurrence of these two exposome components in HNSCC. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways classification shows that most of the genes are specific to cellular metabolism, emphasizing metabolic detoxification pathways, metabolism of chemical carcinogenesis, or drug metabolism. In the case of HPV16-positive patients it has been demonstrated that the altered genes are related to cellular adhesion and inflammation. The correlation between smoking and the survival rate was not statistically significant. This emphasizes the importance of the complex environmental exposure and genetic factors in order to establish prevention assays and personalized care system for HNSCC, with the potential for being extended to other cancer types.

T cell ignorance is bliss: T cells are not tolerized by Langerhans cells presenting human papillomavirus antigens in the absence of costimulation

Human papillomavirus type 16 (HPV16) infections are intra-epithelial, and thus, HPV16 is known to interact with Langerhans cells (LCs), the resident epithelial antigen-presenting cells (APCs). The current paradigm for APC-mediated induction of T cell anergy is through delivery of T cell receptor signals via peptides on MHC molecules (signal 1), but without costimulation (signal 2). We previously demonstrated that LCs exposed to HPV16 in vitro present HPV antigens to T cells without costimulation, but it remained uncertain if such T cells would remain ignorant, become anergic, or in the case of CD4+ T cells, differentiate into Tregs. Here we demonstrate that Tregs were not induced by LCs presenting only signal 1, and through a series of in vitro immunizations show that CD8⁺ T cells receiving signal 1+2 from LCs weeks after consistently receiving signal 1 are capable of robust effector functions. Importantly, this indicates that T cells are not tolerized but instead remain ignorant to HPV, and are activated given the proper signals.

Aetiological heterogeneity of head and neck squamous cell carcinomas: the role of human papillomavirus infections, smoking and alcohol

Tobacco and alcohol consumption are the main risk factors for head and neck squamous cell carcinoma (HNSCC). In addition, human papillomavirus (HPV) infection plays a causal role in oropharyngeal cancer (OPC), a subset of HNSCC. We assessed the independent effects of tobacco, alcohol and HPV infection on OPC risk in the head and neck cancer (HeNCe) Life study, a hospital-based case-control study of HNSCC with frequency-matched controls by age and sex from four Montreal hospitals. Interviewers collected information on socio-demographic and behavioural factors. We tested exfoliated oral cells for HPV DNA by polymerase chain reaction (PCR). We included only OPC cases (n = 188) and controls (n = 427) without missing values for HPV, smoking or alcohol. We examined associations by estimating odds ratios (ORs) and corresponding 95% confidence intervals (CI) using unconditional logistic regression. Smoking (OR = 1.90, 95% CI: 1.04-3.45) and alcohol (OR = 2.74, 95% CI: 1.45-5.15) were associated with an increased risk of OPC independent of HPV status. Positivity for HPV 16 among heavy smokers and heavy alcohol users was associated with a 30.4-fold (95% CI: 8.94-103.26) and 18.6-fold (95% CI: 5.75-60.13) elevation in risk of OPC relative to participants who were HPV negative, respectively. Moreover, the combined effect of heavy smoking and alcohol comsumption with HPV 16 infection substantially increased OPC risk (OR = 48.76, 95% CI: 15.83-150.17) and (OR = 50.60, 95% CI: 15.96-160.40), respectively. Our results support the independent roles of smoking, alcohol and HPV infection in OPC risk and a possible combined effect. Efforts should be made to tackle these major risk factors simultaneously.

Syndemic synergy of HPV and other sexually transmitted pathogens in the development of high-grade anal squamous intraepithelial lesions

Background

Anal intraepithelial neoplasia is associated with high-risk human papillomavirus (hrHPV) as a precursor to anal cancer. However, factors other than hrHPV are likely to be involved and further study of cofactors is required because of the possibility of syndemic interactions.

Methods

Three hundred and fourteen patients underwent 457 operations. Histopathology and hrHPV testing using the Digene Hybrid Capture 2 (HC 2) method were performed. Demographic factors and sexually transmissible infections (STIs) were recorded.

Results

Results showed that hrHPV alone was associated with HSIL (OR = 4.65, p < 0.001). None of the other STIs were alone associated with HSIL but amplification of risk was found when hrHPV infection occurred with HIV (OR = 11.1); syphilis (OR = 5.58); HSV 2 (OR = 7.85); gonorrhoea (OR = 6.45) and some other infections.

Conclusions

These results suggest that hrHPV is a sufficient cause of anal HSIL. Seropositivity for HIV, HSV 2, T. pallidum, HBV and HCV and a history of gonorrhoea or chlamydia exert a powerful amplifying factor increasing the risk of HSIL above the risk with hrHPV alone. Other co-factors which are associated with an increased risk of HSIL are increased age, male gender, MSM behaviour and self-reported history of more than 50 sexual partners. This pattern of disease in patients with warts is characteristic of a syndemic with potential serious increased risk of anal carcinoma.

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High-risk HPV is a necessary and sufficient cause of progression from LSIL to HSIL.

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HIV, HSV 2, HBV and HCV are associated with an amplified risk of hrHPV induced HSIL.

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Gonorrhoea, chlamydia, and syphilis are associated with increased odds HSIL.

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HSIL shows syndemic interaction patterns with STIs and behavioural/social factors.

SLPI and AnxA2 expression in neoplasm-free palatine tonsils is associated with smoking habit of individuals

In order to confirm the inverse correlation between secretory leucocyte protease inhibitor (SLPI) expression, and human papillomavirus (HPV) infection previously observed in head and neck squamous-cell carcinoma, the present study retrospectively investigated the association between SLPI and Annexin A2 (AnxA2) expression, and HPV status in non-neoplastic chronic tonsillitis (n=118), and tonsillar hyperplasia (n=96) tissue. We hypothesised that smoking induces the upregulation of SLPI, resulting in reduced binding of HPV to AnxA2, a known modulator of HPV entry into the cell. SLPI and cyclin-dependent kinase inhibitor 2A (p16^INK4A) protein expression was measured using immunohistochemistry in 214 specimens; SLPI and AnxA2 gene expression was measured using reverse transcription-quantitative polymerase chain reaction in 213 cases; and DNA was isolated from all the specimens to determine HPV status. The association between the results of the aforementioned analyses and the smoking habits of patients was analysed. The samples were HPV-negative. p16^INK4A expression demonstrated moderate and strong staining in 38, and 0 cases, respectively. SLPI expression presented negative, weak and moderate signals in 163, 45, and 6 cases, respectively. A positive correlation was identified between smoking and SLPI (P=0.0001). Gene expression analysis (n=213) revealed that smoking (n=48) resulted in a significant increase in SLPI and AnxA2 expression. A significant positive correlation between AnxA2 and SLPI, indicating a surplus of AnxA2 in relation to SLPI, was exclusively identified in non-smokers. The data demonstrated that smoking results in increased SLPI and AnxA2 expression also in non-neoplastic tonsillar tissue. The observed surplus of AnxA2 in relation to SLPI identified exclusively in the tonsillar tissue of non-smokers indicates a higher possibility of a successful HPV infection of the tonsillar tissue of non-smokers, given the properties of AnxA2 to function as an infection modulator.

miRNA-expression in tonsillar squamous cell carcinomas in relation to HPV infection and expression of the antileukoproteinase SLPI

The aim of this study was to determine if micro-(mi-)RNAs are involved in the previously reported inverse correlation between the antileukoproteinase SLPI, HPV, and smoking habit of head and neck squamous cells carcinoma (HNSCC) patients. HPV-status and SLPI-protein expression were determined in tonsillar SCC (TSCC; n=126). Differentially expressed miRNAs dependent on HPV-status and SLPI-expression were detected by microarray; possible binding-sites in SLPI- and HPVE6-mRNAs were determined in silico. Survival rates were estimated testing prognostic values of HPV-status, SLPI- and miRNA-expression. miRNA-array identified 24 up-regulated and 10 down-regulated miRNAs in HPV-positive versus HPV-negative TSCC (p<0.01; HPV-positivity: 42.1%). HPV-positivity resulted in two up-regulated miRNAs in SLPI-positive TSCC. Of 16 further miRNAs, eight miRNAs were up- and eight were down-regulated in SLPI-negative TSCC. RT-q-PCR-validation of the four most differentially expressed miRNAs showed that miR-363 is expressed strongest in SLPI-negative/HPV-positive TSSC. In silico-analysis of all differentially expressed miRNAs identified miR-363, miR-210, miR-130a, and miR-181a with possible binding sites in the HPV16-E6-mRNA, but none were predicted in the SLPI-mRNA. HPV-positivity, low SLPI-levels and high miR-363-levels are significantly associated with better survival rates. The data presented here show that miR-363 is associated with HPV-positive/SPLI-negative TSCC. The prognostic value of miR-363 suggests a role in the assumed inverse correlation of smoking and SPLI-expression in the mode of HPV-infections in tonsillar but possibly also other HNSCC.

Secretory Leukocyte Protease Inhibitor Expression and High-Risk HPV Infection in Anal Lesions of HIV-Positive Patients

OBJECTIVE

The aim of this study was to evaluate secretory leukocyte protease inhibitor (SLPI) expression in anal biopsies from HIV-positive (HIV+) individuals, and compare that to anal intraepithelial neoplasia (AIN) diagnoses and human papillomavirus (HPV) status.

DESIGN

This is a cross-sectional study of a cohort of 54 HIV+ (31 males and 23 females) from an AIDS clinic in Rio de Janeiro, Brazil.

METHODS

The study material consisted of anorectal tissue biopsies obtained from HIV+ subjects, which were used to construct tissue microarray paraffin blocks for immunohistochemical analysis of SLPI expression. Biopsies were evaluated by an expert pathologist and classified as low-grade AIN1, high-grade AIN2/3, or normal squamous epithelium. In addition, DNA from the biopsies was extracted and analyzed for the presence of low- or high-risk HPV DNA.

RESULTS

Histologically, normal squamous epithelium from the anorectal region showed strong positive SLPI staining in 17/20 (85%) samples. In comparison, 9/17 (53%) dysplastic squamous epithelial samples from AIN1 patients showed strong SLPI staining, and only 5/17 (29%) samples from AIN2/3 patients exhibited strong SPLI staining, which both were significantly fewer than those from normal tissue (P = 0.005). Furthermore, there was a significantly higher proportion of samples in which oncogenic high-risk HPV genotypes were detected in low SLPI-expressing tissues than that in tissues with high SLPI expression (P = 0.040).

CONCLUSIONS

Taken together these results suggest that low SLPI expression is associated with high-risk HPV infections in the development of AIN.

Distribution and factors associated with salivary secretory leukocyte protease inhibitor concentrations

OBJECTIVES

This cross-sectional study examined the distribution and correlates of salivary secretory leukocyte protease inhibitor (SLPI) concentrations within a multinational cohort of men.

METHODS

Extracellular SLPI was measured in oral gargle cell supernatants of 378 men from three countries using an ELISA-based assay. Risk factor data were collected by a questionnaire. Factors associated with SLPI were assessed using linear and logistic regression for continuous and categorical SLPI, respectively.

RESULTS

Among men aged 18-73 years, the median SLPI concentration was 492.0 ng ml^-1 (range: 2.3-1919.9). In multivariable modeling, men in Brazil and younger men (18-30 years) were more likely to have higher levels of SLPI [adjusted odds ratio (aOR) 3.84; 95% confidence interval (CI): 1.94-7.59, and aOR 3.84; 95% CI: 1.98-7.43, respectively]. Men with a self-reported sexually transmitted diseases diagnosis in the past 6 months were more likely to have higher SLPI levels (aOR 2.98; 95% CI: 1.1-7.83) and men reporting bleeding/swollen gums were less likely to have higher SLPI (aOR 0.34; 95% CI: 0.15-0.79). Similar results were observed for linear regression models.

CONCLUSIONS

Secretory leukocyte protease inhibitor concentrations varied significantly by country and decreased with increasing age. The interaction between SLPI, modifiable factors, and oral infections that influence cancer risk warrants further investigation.

Geographic variation in human papillomavirus-related oropharyngeal cancer: Data from 4 multinational randomized trials

BACKGROUND

There are variations in the proportions of head and neck cancers caused by the human papillomavirus (HPV) between countries and regions. It is unclear if these are true variations or due to different study designs and assays.

METHODS

We tested formalin-fixed paraffin-embedded diagnostic biopsies for p16 immunohistochemistry and HPV-DNA (by polymerase chain reaction [PCR] and in situ hybridization [ISH]) using validated protocols on samples from 801 patients with head and neck cancer recruited prospectively between 2006 and 2011 in 4 randomized controlled trials (RCTs).

RESULTS

Twenty-one percent of patients (170 of 801) showed both HPV-DNA and p16-positivity, detected almost exclusively in oropharyngeal cancer (55%; 15 of 302); and only 1% of the patients (5 of 499) with nonoropharyngeal cancer were HPV positive. HPV-positive oropharyngeal cancer differed between Western and Eastern Europe (37%, 155 of 422 vs 6%, 8 of 144; p < .0001) and between Western Europe and Asia (37% vs 2%; 4 of 217; p < .0001). Other independent determinants of HPV positivity were tumor site and smoking.

CONCLUSION

This is the first study to establish geographic variability as an independent risk factor in HPV-positive oropharyngeal cancer prevalence, with higher prevalence in Western Europe. © 2016 The Authors Head & Neck Published by Wiley Periodicals, Inc. Head Neck 38: E1863-E1869, 2016.

Salivary secretory leukocyte protease inhibitor (SLPI) and head and neck cancer: The Cancer Prevention Study II Nutrition Cohort

OBJECTIVES

Secretory leukocyte protease inhibitor (SLPI) is an innate-immunity protein displaying antimicrobial and anti-inflammatory properties that is found in high concentrations in saliva. The role of extracellular salivary SLPI in head and neck squamous cell carcinoma (HNSCC) remains unclear. Thus, we aimed to evaluate the association between SLPI and HNSCC risk in the Cancer Prevention Study II Nutrition Cohort.

MATERIALS AND METHODS

Among 53,180 men and women with no history of cancer who provided an oral rinse between 2001 and 2002, 60 were subsequently diagnosed with incident HNSCC between specimen collection and June 2009. In this nested case-control study, archived oral supernatants were evaluated using the Human SLPI Quantikine ELISA Kit for all 60 cases and 180 controls individually matched on gender, race, date of birth, and date of oral rinse collection. Conditional logistic regression was used to estimate HNSCC risk.

RESULTS

Overall, pre-diagnostic salivary SLPI was associated with a non-statistically significant higher risk of HNSCC (OR=1.6, 95% CI=0.9-3.0). Among never smokers, high SLPI was associated with a non-statistically significant lower risk (OR=0.5, 95% CI=0.1-1.9), whereas among ever smokers, high SLPI was associated with a statistically significant higher risk (OR=2.1, 95% CI=1.0-4.3) of HNSCC, compared to low SLPI.

CONCLUSION

While results from this study suggest that higher concentrations of salivary SLPI might increase the risk of HNSCC among ever smokers, more research is needed to verify these findings and define the mechanisms by which SLPI and smoking influence the etiology of HNSCC.

Predictors of high-risk and low-risk oral HPV infection in the United States

OBJECTIVES/HYPOTHESIS

Determine predictors of high-risk and low-risk oral HPV infection in the United States.

STUDY DESIGN

Retrospective analyses of National Health and Nutrition Examination Survey cross-sectional data of U.S. population from 2009 to 2012.

METHODS

Database queried for subjects aged 18 to 69 with oral rinse human papillomavirus (HPV) DNA data. Logistic regression identified factors associated with high-risk and low-risk infection. Covariates included age, gender, ethnicity, income-to-poverty (IP) ratio, sexual orientation, human immunodeficiency virus infection, other sexually transmitted infections, lifetime sexual partners, and lifetime oral sex partners.

RESULTS

In total, 9,256 subjects were identified with mean age of 42.1 years. Oral HPV infection was present in 8.1% (N = 747); 55.7% were high-risk and 55.3% were low-risk types, including 11% with both. Oral infection had a negative association with female gender (odds ratio [OR] 0.3, P < 0.001), IP ratio ≥ 3 (OR 0.7, P = 0.02), and one lifetime oral sex partner (OR 0.7, P = 0.03). Increasing oral sex behavior (6-21+ lifetime partners) was positively associated with oral HPV (OR 1.4-3.0, P = 0.03). Low-risk infection had negative associations with female gender (OR 0.4, P < 0.001) and non-Hispanic white ethnicity (OR 0.6, P = 0.02), IP ratio ≥ 3 (OR 0.6, P = 0.01), and positive association with > 20 sexual partners (all sex OR 1.7, P = 0.04; oral sex OR 1.9, P = 0.02). Predictors of high-risk HPV infection included male gender and increasing oral sex partners.

CONCLUSION

Increasing oral sex partners is positively associated with oral HPV infection; female sex and higher socioeconomic class are negatively associated. The risk-factor profiles for high-risk and low-risk HPV types are distinct, with similar trends related to sexual behaviors.

LEVEL OF EVIDENCE

4. Laryngoscope, 126:1365-1372, 2016.

Taspase1: a 'misunderstood' protease with translational cancer relevance

Proteolysis is not only a critical requirement for life, but the executing enzymes also play important roles in numerous pathological conditions, including cancer. Therefore, targeting proteases is clearly relevant for improving cancer patient care. However, to effectively control proteases, a profound knowledge of their mechanistic function as well as their regulation and downstream signalling in health and disease is required. The highly conserved protease Threonine Aspartase1 (Taspase1) is overexpressed in numerous liquid and solid malignancies and was characterized as a 'non-oncogene addiction' protease. Although Taspase1 was shown to cleave various regulatory proteins in humans as well as leukaemia provoking mixed lineage leukaemia fusions, our knowledge on its detailed functions and the underlying mechanisms contributing to cancer is still incomplete. Despite superficial similarity to type 2 asparaginases as well as Ntn proteases, such as the proteasome, Taspase1-related research so far gives us the picture of a unique protease exhibiting special features. Moreover, neither effective genetic nor chemical inhibitors for this enzyme are available so far, thus hampering not only to further dissect Taspase1's pathobiological functions but also precluding the assessment of its clinical impact. Based on recent insights, we here critically review the current knowledge of Taspase1's structure-function relationship and its mechanistic relevance for tumorigenesis obtained from in vitro and in vivo cancer models. We provide a comprehensive overview of tumour entities for which Taspase1 might be of predictive and therapeutic value, and present the respective experimental evidence. To stimulate progress in the field, a comprehensive overview of Taspase1 targeting approaches is presented, including coverage of Taspase1-related patents. We conclude by discussing future inhibition strategies and relevant challenges, which need to be resolved by the field.

Herpes simplex virus downregulation of secretory leukocyte protease inhibitor enhances human papillomavirus type 16 infection

Herpes simplex virus (HSV) was originally implicated in the aetiology of cervical cancer, and although high-risk human papillomavirus (HPV) is now the accepted causative agent, the epidemiological link between HSV and HPV-associated cancers persists. The annexin A2 heterotetramer (A2t) has been shown to mediate infectious HPV type 16 (HPV16) uptake by human keratinocytes, and secretory leukocyte protease inhibitor (SLPI), an endogenous A2t ligand, inhibits HPV16 uptake and infection. Interestingly, HSV infection induces a sustained downregulation of SLPI in epithelial cells, which we hypothesized promotes HPV16 infection through A2t. Here, we show that in vitro infection of human keratinocytes with HSV-1 or HSV-2, but not with an HSV-1 ICP4 deletion mutant that does not downregulate SLPI, leads to a >70% reduction of SLPI mRNA and a >60% decrease in secreted SLPI protein. Consequently, we observed a significant increase in the uptake of HPV16 virus-like particles and gene transduction by HPV16 pseudovirions (two- and 2.5-fold, respectively) in HSV-1- and HSV-2-infected human keratinocyte cell cultures compared with uninfected cells, whereas exogenously added SLPI reversed this effect. Using a SiMPull (single-molecule pulldown) assay, we demonstrated that endogenously secreted SLPI interacts with A2t on epithelial cells in an autocrine/paracrine manner. These results suggested that ongoing HSV infection and resultant downregulation of local levels of SLPI may impart a greater susceptibility for keratinocytes to HPV16 infection through the host cell receptor A2t, providing a mechanism that may, in part, provide an explanation for the aetiological link between HSV and HPV-associated cancers.

Respiratory protease/antiprotease balance determines susceptibility to viral infection and can be modified by nutritional antioxidants

The respiratory epithelium functions as a central orchestrator to initiate and organize responses to inhaled stimuli. Proteases and antiproteases are secreted from the respiratory epithelium and are involved in respiratory homeostasis. Modifications to the protease/antiprotease balance can lead to the development of lung diseases such as emphysema or chronic obstructive pulmonary disease. Furthermore, altered protease/antiprotease balance, in favor for increased protease activity, is associated with increased susceptibility to respiratory viral infections such as influenza virus. However, nutritional antioxidants induce antiprotease expression/secretion and decrease protease expression/activity, to protect against viral infection. As such, this review will elucidate the impact of this balance in the context of respiratory viral infection and lung disease, to further highlight the role epithelial cell-derived proteases and antiproteases contribute to respiratory immune function. Furthermore, this review will offer the use of nutritional antioxidants as possible therapeutics to boost respiratory mucosal responses and/or protect against infection.

Advancements in the Management of HPV-Associated Head and Neck Squamous Cell Carcinoma

Head and neck carcinomas have long been linked to alcohol and tobacco abuse; however, within the last two decades, the human papillomavirus (HPV) has emerged as a third etiology and is specifically associated with head and neck squamous cell carcinomas (HNSCC). In this anatomical region, the oncogenic HPV-16 mediates transformation and immortalization of epithelium, most commonly in the oropharynx. Nevertheless, the recent identification of novel HPV mechanisms thought to be specific to oropharyngeal carcinogenesis has coincided with observations that HPV-associated HNSCC has differing clinical behavior-in terms of natural history, therapeutic response, and prognosis-than HPV-negative head and neck tumors. Taken together with the growing incidence of HPV transmission in younger populations, these discoveries have sparked a rapid expansion in both laboratory and clinical studies on the infection and disease. Herein, we review the clinical characteristics of HPV-associated HNSCC, with particular emphasis on recent advancements in our understanding of the management of this infectious malignancy.

Small molecule inhibitors of the annexin A2 heterotetramer prevent human papillomavirus type 16 infection

OBJECTIVES

High-risk human papillomavirus (HPV) infection leads to the development of several human cancers that cause significant morbidity and mortality worldwide. HPV type 16 (HPV16) is the most common of the cancer-causing genotypes and gains entry to the basal cells of the epithelium through a non-canonical endocytic pathway that involves the annexin A2/S100A10 heterotetramer (A2t). A2t is composed of two annexin A2 monomers bound to an S100A10 dimer and this interaction is a potential target to block HPV16 infection. Here, recently identified small molecule inhibitors of A2t (A2ti) were investigated for their ability to prevent HPV16 infection in vitro.

METHODS

A2ti were added to HeLa cells in increasing concentrations prior to the addition of HPV16. Cytotoxicity was evaluated via trypan blue exclusion. HPV16 pseudovirion infection and fluorescently labelled HPV16 capsid internalization was measured with flow cytometry.

RESULTS

A2ti blocked HPV16 infection by 100% without substantial cellular toxicity or reduction in cell growth. Furthermore, A2ti blocked HPV16 entry into epithelial cells by 65%, indicating that the observed inhibition of HPV16 infection is in part due to a block in entry and that non-infectious entry may occur in the absence of A2t binding.

CONCLUSIONS

These results demonstrate that targeting A2t may be an effective strategy to prevent HPV16 infection.

The antileukoprotease secretory leukocyte protease inhibitor (SLPI) and its role in the prevention of HPV-infections in head and neck squamous cell carcinoma

Recently, we demonstrated a significant inverse correlation between HPV-infection and SLPI-expression suggesting that SLPI protects against HPV-infection of HNSCC. Here we analyzed in a single lab setting 307 formalin-fixed paraffin-embedded HNSCC cases (tonsillar n = 135; non-tonsillar: n = 172) from eight health care centers. Samples were analyzed for SLPI gene- and protein-expression. Annexin A2, its heterotetramer A2t, putatively facilitating HPV- and SLPI-cell entry, was measured to study the correlation between SLPI and annexin A2. Data were correlated with tobacco consumption and HPV-status. Overall, HPV-DNA prevalence was 23.5% (72/307); attributed to: 43.7% (59/135) tonsillar and 7.6% (13/172) non-tonsillar cases. Smoking resulted in 6.44-fold increased and HPV-infection in 3.46-fold decreased SLPI-gene expression in all HNSCC with similar significant results obtained in tonsillar and non-tonsillar SCC separately. Correlating annexin A2- and SLPI-gene expression showed a significant surplus of annexin A2 in HPV-positive tumors (4.21× more annexin A2) and 6.72× more annexin A2 than SLPI in nonsmokers in all HNSCCs and similar significant results for both tumor entities separately. The surplus of annexin A2 in non-smokers and HPV-positive patients supports our hypothesis that decreased SLPI levels facilitate HPV-infection i.e., increased SLPI-expression may protect against HPV-infection of tonsillar and non-tonsillar SCC.

Nodal metastasis and survival in oral cancer: Association with protein expression of SLPI, not with LCN2, TACSTD2, or THBS2

BACKGROUND

Gene expression profiling revealed a strong signature predicting lymph node metastases in oral squamous cell carcinoma (OSCC). Four of the most predictive genes are secretory leukocyte protease inhibitor (SLPI), lipocalin-2 (LCN2), thrombospondin-2 (THBS2), and tumor-associated calcium signal transducer 2 (TACSTD2). This study correlates their protein expression with lymph node metastases, overall survival (OS), and disease-specific survival (DSS).

METHODS

Two hundred twelve patients with OSCC were included for protein expression analysis by immunohistochemistry.

RESULTS

SLPI expression correlates with lymph node metastases in the whole cohort, not in a subgroup of cT1 to 2N0. SLPI expression correlates with OS (hazard ratio [HR] = 0.61) and DSS (HR = 0.47) in multivariate analysis. LCN2, THBS2, and TACSTD2 show no correlation with lymph node metastases, OS, or DSS.

CONCLUSION

Although SLPI expression correlates with lymph node metastases, it has no additional value in determining lymph node metastases in early oral cancer. However, it is an independent predictor for both OS and DSS and therefore a relevant prognostic biomarker in OSCC.

Secreted mucosal antimicrobials in the female reproductive tract that are important to consider for HIV prevention

The mucosal microenvironment of the female reproductive tract (FRT) is rich in secreted endogenous antimicrobials that provide the first line of defense against pathogens. This review focuses on the spectrum of secreted antimicrobials found in the FRT that have anti-HIV functions and are regulated by the natural hormonal changes in women's life cycle. Understanding the complex nature of FRT, mucosal microenvironment will enable us to better design therapeutic interventions for women against sexually transmitted pathogens.

Quantification of secretory leukocyte protease inhibitor (SLPI) in oral gargle specimens collected using mouthwash

BACKGROUND

Secretory leukocyte protease inhibitor (SLPI) is an innate immunity-associated protein known to inhibit HIV transmission, and is thought to inhibit a variety of infectious agents, including human papillomaviruses (HPVs). We aimed to optimize an established ELISA-based SLPI quantification assay for use with oral gargle specimens collected using mouthwash, and to assess preliminary associations with age, smoking status, and alcohol intake.

METHODS

Oral gargle supernatants from 50 individuals were used to optimize the Human SLPI Quantikine ELISA Kit. Sample suitability was assessed and quality control analyses were conducted.

RESULTS

Salivary SLPI was successfully recovered from oral gargles with low intra-assay and high inter-individual variability. Initial measurements showed that salivary SLPI varied considerably across individuals, and that SLPI was inversely associated with age.

CONCLUSIONS

This optimized assay can be used to examine the role of SLPI in the acquisition of oral HPV and other infections.

The role of the antileukoprotease SLPI in smoking-induced human papillomavirus-independent head and neck squamous cell carcinomas

Recently, we showed that increased SLPI levels prevent human papillomavirus (HPV) infections and metastasis in smoking-induced, non-HPV-driven head and neck squamous cell carcinoma (HNSCC). Here, we focus on the role of SLPI in non-HPV-driven HNSCC, investigating tumor tissue and non-neoplastic mucosa from the same patients and from non-HNSCC patients. Gene and protein expression of SLPI and gene expression of annexin 2 (a SLPI receptor), nicotine receptor (α7AChR) and arylhydrocarbon receptor (AhR) were analyzed in HNSCC patients (20 smokers; 16 nonsmokers). SLPI-results were correlated with the patients' HPV status. Non-neoplastic mucosa of HNSCC patients and normal mucosa from non-HNSCC individuals (18 smokers; 20 nonsmokers) was analyzed for the same parameters. Tissue of the inferior turbinate (n = 10) was incubated with nicotine for analysis of the same genes. SLPI gene expression in tumor tissue was 109.26 ± 23.08 times higher in smokers versus nonsmokers. Non-neoplastic mucosa of smokers showed also higher SLPI gene expression (10.49 ± 1.89-fold non-HNSCC; 18.02 ± 3.93-fold HNSCC patients). Annexin 2 gene expression was also increased in smokers. SLPI data were corroborated by immunohistochemistry. A nicotine dependent correlation between SLPI and annexin 2 gene expression (r(2) = 0.15, p < 0.001) was shown ex vivo. Nicotine and smoking increased α7AChR and AhR gene expression. Five patients, showing no/low SLPI expression, were HPV16-positive. A significant correlation between smoking and SLPI expression in tumors and to our knowledge for the first time in mucosa of HNSCC and non-HNSCC patients was established. Together with the finding that all patients with HPV infection showed no/low SLPI expression, these data support our intriguing hypothesis that smoking induced upregulated SLPI prevents HPV infections.

Human papillomaviruses and cancer

Human papillomaviruses (HPV) are small oncogenic DNA viruses of which more than 200 types have been identified to date. A small subset of these is etiologically linked to the development of anogenital malignancies such as cervical cancer. In addition, recent studies established a causative relationship between these high-risk HPV types and tonsillar and oropharyngeal cancer. Clinical management of cervical cancer and head and neck squamous cell carcinomas (HNSCCs) is largely standardized and involves surgical removal of the tumor tissue as well as adjuvant chemoradiation therapy. Notably, the response to therapeutic intervention of HPV-positive HNSCCs has been found to be better as compared to HPV-negative tumors. Although the existing HPV vaccine is solely licensed for the prevention of cervical cancer, it might also have prophylactic potential for the development of high-risk HPV-associated HNSCCs. Another group of viruses, which belongs to the beta-HPV subgroup, has been implicated in nonmelanoma skin cancer, however, the etiology remains to be established. Treatment of HPV-induced nonmelanoma skin cancer is based on local excision. However, topically applied immune-modulating substances represent non-surgical alternatives for the management of smaller cutaneous tumors. In this review we present the current knowledge of the role of HPV in cancer development and discuss clinical management options as well as targets for the development of future intervention therapies.