Karin Danielsson

Altered expression of miR-21, miR-125b, and miR-203 indicates a role for these microRNAs in oral lichen planus

BACKGROUND Oral lichen planus (OLP), which is a chronic inflammatory disease of the oral mucosa with unknown etiology, affects about 2% of the population. MicroRNAs are small non-coding RNAs involved in normal processes such as development and differentiation as well as progression of human diseases. The aim of this study was to investigate the expression of miR-21, miR-125b, and miR-203 and to compare RNA levels of their potential targets, the tumor suppressor p53 and its relative p63, both known to be deregulated in OLP. METHODS In biopsies from 20 patients with OLP and 20 age- and sex-matched healthy controls, epithelium was laser dissected and analyzed for the expression of miR-21, miR-125b, miR-203, p53, and p63 using qRT/PCR. RESULTS Increased expression of miR-21 and miR-203, decreased expression of miR-125, and down-regulation of p53 and ΔNp63 RNA were seen in OLP compared to normal oral mucosa. When comparing microRNA expression to levels of p53 and p63 RNA, a significant negative correlation was seen between ΔNp63 and miR-203 and between miR-21 and p53, respectively. CONCLUSION Results indicate a role for the studied microRNAs in changes seen in OLP.

Increased levels of COX‐2 in oral lichen planus supports an autoimmune cause of the disease

Background  Oral lichen planus (OLP) is a chronic inflammatory disease for which the pathogenesis is not fully understood. OLP has autoimmune features and auto immunity has been suggested as a potential cause, whereas WHO has classified OLP as a premalignant condition. Association between chronic inflammation and cancer is known and chronic inflammation is one of the characteristics of OLP. A protein connected to inflammation and suggested to be involved in cancer development is cyclooxygenase‐2 (COX‐2) which can be inhibited by microRNA‐26b (miR‐26b).

Distributed participatory design

Over the years a consensus has developed that involving users directly in the software development process can lead to more useful and usable systems. This has found its clearest expression in the Participatory Design (PD) movement. However, a limitation of PD is that it has primarily focused on project stakeholders being co-located, whereas in recent years we are starting to see software development projects involve more distributed collaborations. This workshop is aimed at researchers and practitioners with an interest to overcome the challenges of performing PD in distributed design teams. Several critical issues need examination in order to understand the usefulness and constraints of distributed participatory design (DPD).

Expression of p16 in squamous cell carcinoma of the mobile tongue is independent of HPV infection despite presence of the HPV-receptor syndecan-1.

Background:Tongue squamous cell carcinoma (TSCC) is increasing in incidence, especially among young patients and preferably females. Infection with human papilloma virus (HPV) has been suggested as a cause of SCC in the head and neck, and the proportion of oropharyngeal cancers caused by HPV has steadily increased.Methods:Samples from 109 patients with primary TSCC were analysed for the presence of HPV16 by in situ hybridisation and for expression of its surrogate marker p16 and the HPV receptor syndecan-1 by immunhistochemistry.Results:No evidence of HPV16 DNA was observed in the tumours, although one-third showed p16 staining. There was no difference in the expression of the primary HPV receptor, syndecan-1, between TSCC and a group of tonsil SCC.Conclusion:Whereas p16 is expressed in some TSCCs, HPV16 is undetectable, therefore, p16 cannot be used as a surrogate marker for high-risk HPV-infection in this tumour. Despite presence of the HPV-receptor syndecan-1 in TSCC, HPV prefers the tonsillar environment. Lack of p16 associates with worse prognosis primarily in patients aged ⩽40 years with tongue SCC. The improved prognosis seen in p16-positive TSCC can be due to induction of a senescent phenotype or an inherent radiosensitivity due to the ability of p16 to inhibit homologous recombination repair.

Increased expression of Smad proteins, and in particular Smad3, in oral lichen planus compared to normal oral mucosa

BACKGROUND Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa which the World Health Organisation (WHO) considers a premalignant condition. One step in malignant development is so called epithelial mesenchymal transition (EMT), a process whereby epithelial cells acquire mesenchymal characteristics. EMT occurs during embryogenesis and wound healing but also in some human diseases such as cancer and fibrosis. A factor known to induce EMT is transforming growth factor-β (TGF-β), which uses the Smad proteins as mediators for its signalling. TGF-β is also often over-expressed in squamous cell carcinoma of the head and neck (SCCHN). METHODS In the present study we mapped expression of Smad proteins in OLP lesions by immunohistochemistry, and compared to expression in normal and sensitive oral mucosa. The latter group of patients had developed SCCHN after shorter or longer periods of diffuse oral symptoms. The aim was to see if there were any signs of EMT related changes in the OLP lesions, as judged by changes in the TGF-β pathway. CONCLUSION Changes in the TGF-β pathway related to EMT are seen in the very earliest stages of oral malignancy and become more severe as lesions progress.

Autoantibodies and decreased expression of the transcription factor ELF-3 together with increased chemokine pathways support an autoimmune phenotype and altered differentiation in lichen planus located in oral mucosa

Background  The pathogenesis of oral lichen planus (OLP), a chronic inflammatory disease, is not fully understood. It is known that OLP has autoimmune features, and it is suggested to be an autoimmune disease. ELF‐3 is involved in differentiation of keratinocytes and deregulated in different tumours and inflammatory diseases. CXCR‐3 and its ligands CXCL‐10 and CXCL‐11 are increased in autoimmune diseases and linked to Th‐1 immune response.

Genes involved in epithelial differentiation and development are differentially expressed in oral and genital lichen planus epithelium compared to normal epithelium.

Lichen planus (LP) is a chronic mucocutaneous disease with unknown cause. Patients with LP often have both oral and genital lesions, but these conditions are often considered as separate diseases and treated accordingly. To find out which genes are differently expressed in mucosal LP compared to normal mucosa and establish whether oral and genital LP are in fact the same disease, whole genome expression analysis was performed on epithelium from 13 patients diagnosed with oral and/or genital LP and normal controls. For confirmation of keratin 4 and corneodesmosin expression, quantitative reverse-transcription PCR and immunohistochemistry were used. Many genes involved in epithelial development and differentiation are differently expressed in epithelium from LP compared to normal epithelium. Several of the differentially expressed genes are common for oral and genital LP and the same biological processes are altered which supports the fact that oral and genital LP are manifestations of the same disease. The change in gene expression indicates that differentiation is altered leading to changes in the epithelial barrier.

Alterations in factors involved in differentiation and barrier function in the epithelium in oral and genital lichen planus

Lichen planus is a chronic recurrent inflammatory disease affecting both skin and mucosa, mainly in oral and/or genital regions. Keratinocytes go through a well-regulated process of proliferation and differentiation, alterations in which may result in defects in the protective epithelial barrier. Long-term barrier impairment might lead to chronic inflammation. In order to broaden our understanding of the differentiation process in mucosal lichen planus, we mapped the expression of 4 factors known to be involved in differentiation. Biopsies were collected from oral and genital lichen planus lesions and normal controls. Altered expression of all 4 factors in epithelium from lichen planus lesions was found, clearly indicating disturbed epithelial differentiation in lichen planus lesions.

High expression of podoplanin in squamous cell carcinoma of the tongue occurs predominantly in patients ≤40 years but does not correlate with tumour spread

More than 30% of patients with squamous cell carcinoma (SCC) of the mobile tongue have clinically undetectable lymph node metastasis. Tumour cells can spread as single cells or collectively. A protein known to play a role in both processes is podoplanin, which is expressed in endothelial cells not only in lymph vessels but also in some aggressive tumours with high invasive and metastatic potential. Here we studied samples from 129 patients with primary SCC of the tongue for expression of podoplanin using immunohistochemistry. mRNA levels were analysed in another 27 cases of tongue SCC with adjacent clinically tumour‐free tongue tissue and 14 tongue samples from healthy donors. Higher levels of podoplanin were seen in tumours compared to both normal tongue and clinically normal tongue in the tumour vicinity. No association was found between levels of podoplanin, presence of lymph node metastases or other clinical factors. Patients aged 40 or less were more likely to express high levels of podoplanin protein compared to older patients (p = 0.027). We conclude that levels of podoplanin in primary tongue SCCs are not associated with lymph node metastases. However, tongue SCCs arising in young patients (≤40 years of age) are more likely to express high levels of podoplanin than tongue SCCs that arise in the more elderly. The data suggest that podoplanin has a distinctive role in young patients, who are known to have a poor prognosis: these patients may, therefore, benefit from podoplanin inhibitory therapies.

Difficulties detecting miRNA-203 in human whole saliva by the use of PCR

Objectives: Oral Lichen Planus (OLP) is a chronic disease of the oral mucosa, and according to the WHO also a pre malignant condition. Micro-RNAs are short non coding RNAs capable of regulating mRNA expression. MiRNA:scan be detected in tissue, blood and human whole saliva (HWS) and recently we have shown miR-203 to be up-regulated in tissue from OLP lesions. Study Design: In order to see whether mRNA as well as miR-203 could be detected also in HWS, saliva from healthy controls and patients with OLP were analysed using two different PCR methods. Results: Results showed low mRNA and miRNA levels in general in HWS samples, making it hard to generate conclusive results. Conclusions: In order to make HWS a valuable source for different analyses, more sensitive PCR techniques capable of detecting very low levels of mRNAand miRNAas well as more efficient methods for extraction of RNA are needed. Key words:miRNA-203, saliva, PCR.