Human papillomaviruses (HPV) are associated with a subset of head and neck squamous cell carcinoma (HNSCC), particularly HPV16. This study analyzed the presence and genotype of high risk HPVs, viral DNA load and transcription of the E6/E7 mRNAs, in 231 consecutive HNSCC. Twelve out of 30 HPV16 DNA-positive tumors displayed high E6/E7 mRNAs levels and were localized in the oropharyngeal region. While HPV-free and non-transcriptionally active HPV-related patients showed similar 5-years survival rates, E6/E7 expression was associated with a better prognosis. This emphasizes the importance of considering the transcriptional status of HPV-positive tumors for patient stratification. A gene expression profiling analysis of these different types of tumors was carried out. The most significant differentially expressed gene was CDKN2A, a known biomarker for HPVrelated cancer. Assessing both the expression level of the E6/E7 mRNAs and of CDKN2A in HNSCC is required to detect active HPV infection. Chromosomic alterations were investigated by Comparative Genomic Hybridation (CGH) analysis of tumors with transcriptionally active HPV and HPV-negative tumors. The loss of the chromosomal region 16q was found to be a major genetic event in HPV-positive lesions. A cluster of genes located in 16q21-24 displayed decreased expression levels, notably APP-BP1 that is involved in the modulation of the transcriptional activity of p53. In conclusion, this study highlights important criteria required to predict clinically active HPV infection, identifies new biological pathways implicated in HPV tumorigenesis and increases the understanding of HPV-HNSCC physiopathology that is required to develop new targets for therapy.Heavy consumption of tobacco and alcohol are the major risk factors for head and neck squamous cell carcinoma (HNSCC). However, recent epidemiological data indicate that high-risk human papillomavirus (HR-HPV), similar to those involved in cervical cancer onset and development, are associated with a subset of HNSCC 1 (for comprehensive review, see Refs. 2 and 3 and references therein). The anatomic site mostly associated with HPV infection in the upper aerodigestive tract is the oropharynx, especially the tonsils and tongue base. [4][5][6][7] The oncogenic potential of HPV involves the expression of the E6 and E7 viral oncoproteins, which disrupt the p53 and pRB signalling pathways, respectively. Typically, the absence of genetic or epigenetic alterations in the p53 and pRb pathways in HPV-positive cancer distinguishes them from HPV-negative disease.
Catestatin (bCGA(344-364)), an endogenous peptide of bovine chromogranin A, was initially characterized for its effect on the inhibition of catecholamine release from chromaffin cells. Catestatin and its active domain (bCGA(344-358)) were identified in chromaffin cells and in secretion medium. The present study identified a potent antimicrobial activity of bCGA(344-358) in the lowmicromolar range against bacteria, fungi and yeasts, without showing any haemolytic activity. Confocal laser microscopy demonstrated penetration of the rhodaminated peptide into the cell membranes of fungi and yeasts and its intracellular accumulation. Time-lapse videomicroscopy showed arrest of fungal growth upon penetration of the labelled peptide into a fungal filament. We identified several catestatin-containing fragments in the stimulated secretion medium of human polymorphonuclear neutrophils, suggesting the N-terminal sequence of catestatin (bCGA(344-358)) (named cateslytin) as a novel component of innate immunity.
Integration of human papillomavirus (HPV) DNA into the host cell genome is a frequent event in cervical carcinogenesis, even though this phenomenon does not seem to be mandatory for cervical cancer development. Our objective was to describe the load and physical state of HPV type 16 (HPV16) DNA in a series of cervical samples representative of the natural history of cervical cancer. We used a combination of three real-time PCR assays targeting E6, E2, and albumin genes to calculate HPV16 load (E6 and albumin) and the E2/E6 ratio as a surrogate of integration. This method was applied to 173 HPV16-positive cervical samples. Results show that viral load increases with the lesion grade (from 102 HPV16 DNA copies per 10 3 cells in normal samples up to 56,354 copies per 10 3 cells in cancers), while E2/E6 ratio decreases (from 1 in normal samples down to 0.36 in cancers). We propose that, according to this technique, an HPV16 viral load of higher than 22,000 copies/10 3 cells or an E2/E6 ratio of lower than 0.50 allows the identification of women with prevalent high-grade lesions or worse with a high specificity. In conclusion, both viral load and E2/E6 ratio, used in combination with an appropriate cutoff value, are suitable to screen women with prevalent cervical intraepithelial neoplasia grade 2 or 3 or cancer. Therefore, these assays would be useful in addition to routine HPV testing to more accurately identify women with (pre)cancerous lesions.
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