ABSTRACT
The life cycle of human papillomaviruses (HPVs) is strictly linked to the differentiation of their natural host cells. The HPV E6 and E7 oncoproteins can delay the normal differentiation program of keratinocytes; however, the exact mechanisms responsible for this have not yet been identified. The goal of this study was to investigate the effects of HPV16 oncoproteins on the expression of genes involved in keratinocyte differentiation. Primary human keratinocytes transduced by LXSN (control) retroviruses or virus vectors expressing HPV16 E6, E7 or E6/E7 genes were subjected to gene expression profiling. The results of microarray analysis showed that HPV 16 E6 and E7 have the capacity to downregulate the expression of several genes involved in keratinocyte differentiation. Quantitative real-time polymerase chain reaction (qRT-PCR) assays were performed to confirm the microarray data. To investigate the effects of the HPV oncoproteins on the promoters of selected keratinocyte differentiation genes, luciferase reporter assays were performed. Our results suggest that the HPV 16 E6 and/or E7 oncogenes are able to downregulate the expression of several genes involved in keratinocyte differentiation (such as desmocollin 1, keratin 4, S100 calcium-binding protein A8 and small proline-rich protein 1A), at least partially by downregulating their promoter activity. This activity of the HPV oncoproteins may have a role in the productive virus life cycle, and also in virus-induced carcinogenesis.
Subject(s)
Cell Differentiation/genetics , Gene Expression Regulation , Human papillomavirus 16/metabolism , Keratinocytes/cytology , Oncogene Proteins, Viral/metabolism , Papillomavirus E7 Proteins/metabolism , Repressor Proteins/metabolism , Base Sequence , CCAAT-Enhancer-Binding Proteins/genetics , Calgranulin A/biosynthesis , Carcinogenesis/genetics , Cells, Cultured , Desmocollins/biosynthesis , Down-Regulation , Gene Expression Profiling , Human papillomavirus 16/genetics , Humans , Keratin-4/biosynthesis , Keratinocytes/virology , Oncogene Proteins, Viral/genetics , Papillomavirus E7 Proteins/genetics , Promoter Regions, Genetic/genetics , Repressor Proteins/genetics , Sequence Analysis, DNA , Transcription Factor AP-1/genetics , Transcription Factors/antagonists & inhibitors , Transcription, Genetic , Transduction, GeneticABSTRACT
Localized primary cutaneous amyloidosis is uncommon in Europe and North America and is infrequently reported in the English literature. The constituents of such deposits have not been previously examined; this series characterizes amyloid deposits in localized vulvar amyloidosis and their association with vulvar intraepithelial neoplasia. All biopsies and excisions of vulva over 18 months were reviewed. Cases with suspected amyloidosis were retrieved after institutional review board approval. Twenty cases mimicking amyloidosis were selected as controls. All study and control cases were stained with Congo red. Four Congo red-positive study cases were studied by liquid chromatography-tandem mass spectrometry. Of 27 Congo red-positive study cases, 25 were then examined by immunohistochemical stains with antibodies to cytokeratin 5 (CK5) and cytokeratin 14 (CK14). Of 149 cases reviewed, 26 localized and 1 systemic vulvar amyloidosis were identified. Liquid chromatography-tandem mass spectrometry analysis of the deposits revealed unique peptide profile consistent with CK5 and CK14. Immunohistochemical staining with antibodies to CK5 and CK14 also detected these components in the deposits. The vulvar deposit of systemic amyloidosis consisted of amyloid light chain (λ)-type amyloid deposit. All control cases were negative for Congo red. Keratin-associated amyloid materials (CK5 and CK14) were found to be unique in localized vulvar amyloidosis. Leakage of keratins from the basal layer of the epithelium into the superficial dermis may have been the possible source of the deposits. It appears to be associated with both high-grade and low-grade vulvar intraepithelial neoplasias and, rarely, lichen sclerosus, seborrheic keratosis, and benign vulvar skin.
