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Citrullination is an emerging post-translational modification catalyzed by peptidylarginine deiminases (PADs) that convert peptidyl-arginine into peptidyl-citrulline. In humans, the PAD family consists of five isozymes (PADs 1-4, 6) involved in multiple diseases, including cancer. Given that high-risk (hr) human papillomaviruses (HPVs) are the etiological agents of cervical cancer, in this study, we sought to determine whether PAD-mediated protein citrullination would play a functional role in the HPV-driven transformation of epithelial cells. Here we show that both total protein citrullination and PAD4 expression levels are significantly associated with cervical cancer progression. Specifically, epithelial immunostaining for PAD4 revealed an increasingly higher histoscore from lowgrade (CIN1) to high-grade (CIN2, CIN3) cervical intraepithelial neoplasia, and invasive squamous cell carcinoma (SCC) lesions, raising the attractive possibility that PAD4 may be used as tumor staging markers. Furthermore, taking advantage of the epidermoid cervical cancer cell line CaSki, which harbors multiple copies of the integrated HPV16 genome, we show that the expression of E6 and E7 HPV oncoproteins is impaired by treatment with the pharmacological pan-PAD inhibitor BB-Cl-amidine. Consistently, p53 and p21, two targets of HPV oncoproteins, are upregulated by the PAD inhibitor, which undergoes cell growth arrest and apoptosis. Altogether, these findings highlight a novel mechanism by which hrHPVs alter host regulatory pathways involved in cell cycle and survival to gain viral fitness, raising the possibility that PADs may represent an attractive target for developing novel host-targeting antivirals effective in preventing cervical cancer progression. [ABSTRACT FROM AUTHOR]

The aims of this study were to investigate OX40 ligand expression in sinus tissue from patients with nasal polyposis compared with patients with chronic rhinosinusitis without nasal polyps (NPs), and to determine if OX40 ligand expression is related to eosinophilic sinus infiltration. Twenty patients with chronic rhinosinusitis (11 with and nine without NPs) and seven controls were enrolled in the study. The mRNA expression of OX40 ligand and thymic stromal lymphopoietin and its receptor were analyzed. The immunoreactivity score for OX40 ligand and the eosinophil count were obtained. The mRNA expression and immunoreactivity score of OX40 ligand were higher in patients with nasal polyposis than in patients without NPs, as well as healthy controls. The mRNA expression of thymic stromal lymphopoietin and its receptor was significantly higher in nasal polyposis than in the control, but not significantly higher than in chronic rhinosinusitis without NPs. A correlation between the number of OX40 ligand-positive cells and the number of eosinophils in sinus biopsies was found only in patients with nasal polyposis. In conclusion, the thymic stromal lymphopoietin/OX40 ligand axis is up-regulated in nasal polyposis and is related to the intensity of eosinophilic inflammation. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyze protein and gene expression of HER2 in 224 head and neck precancerous and malignant lesions by immunohistochemistry and FISH analysis. In parallel, expression of pStat3, Sox2, IFI16 and p16, Ki67 was evaluated. Immunohistochemical analysis was assessed on formalin-fixed paraffin-embedded (FFPE) tissue specimens. A combined method for HPV detection consisting of p16 immunostaining and two PCR probes was applied. HER2 gene status was evaluated by FISH analysis. HPV DNA was detected in 24% of cases with predominant HPV16 genotype. HPV-positive lesions had higher HER2, pStat3 and within carcinoma group, and higher IFI16 expression compared to the HPV-negative group (Fig. 1A-B-C). A strong positive correlation between Sox2 and proliferative activity was observed, whereas IFI16 expression displayed a negative relationship with Sox2 and Ki67 activity. The most striking result was higher pStat3 expression in HPV-positive lesions and its strong positive correlation with IFI16 expression. The presence of HPV may induce upregulation of HER2/neu, pStat3 and IFI16. High levels and a strong positive correlation between pStat3 and IFI16 suggest their synergistic pro-apoptotic effects in HPV-positive lesions.

The association between human papillomavirus (HPV) DNA positivity, p53 codon 72 polymorphisms, and the type of leukocyte infiltration in head and neck squamous cell carcinomas (HNSCC) and their combined impact upon patient survival is poorly investigated. For this reason, leukocyte infiltration profile and p53 codon 72 polymorphisms were assessed in freshly removed HNSCC specimens (N=71 patients). HPV detection was performed by nested-PCR followed by DNA sequencing. Viral loads were determined by quantitative RT-PCR. The choice to investigate fresh instead of archive paraffin-embedded specimens was privileged to avoid possible artifacts due to sample processing. HPV DNA was detected in 14% of cases. Oropharyngeal carcinomas were the most frequently associated with the presence of HPV16 DNA (41%) and were associated with p53 Pro/Pro or Pro/Arg polymorphisms. In HPV16-positive oropharyngeal carcinomas increased infiltrations of CD3+ and FoxP3+ T-cells correlated with higher HPV16 copy numbers. The presence of HPV may trigger a stronger immune response and may be considered a reliable marker for clinical staging and a more favorable prognosis of oropharyngeal carcinoma.