Juha P. Väyrynen

IL-17/Th17 pathway is activated in acne lesions.

The mechanisms of inflammation in acne are currently subject of intense investigation. This study focused on the activation of adaptive and innate immunity in clinically early visible inflamed acne lesions and was performed in two independent patient populations. Biopsies were collected from lesional and non-lesional skin of acne patients. Using Affymetrix Genechips, we observed significant elevation of the signature cytokines of the Th17 lineage in acne lesions compared to non-lesional skin. The increased expression of IL-17 was confirmed at the RNA and also protein level with real-time PCR (RT-PCR) and Luminex technology. Cytokines involved in Th17 lineage differentiation (IL-1β, IL-6, TGF-β, IL23p19) were remarkably induced at the RNA level. In addition, proinflammatory cytokines and chemokines (TNF-α, IL-8, CSF2 and CCL20), Th1 markers (IL12p40, CXCR3, T-bet, IFN-γ), T regulatory cell markers (Foxp3, IL-10, TGF-β) and IL-17 related antimicrobial peptides (S100A7, S100A9, lipocalin, hBD2, hBD3, hCAP18) were induced. Importantly, immunohistochemistry revealed significantly increased numbers of IL-17A positive T cells and CD83 dendritic cells in the acne lesions. In summary our results demonstrate the presence of IL-17A positive T cells and the activation of Th17-related cytokines in acne lesions, indicating that the Th17 pathway is activated and may play a pivotal role in the disease process, possibly offering new targets of therapy.

VE1 immunohistochemistry accurately detects BRAF V600E mutations in colorectal carcinoma and can be utilized in the detection of poorly differentiated colorectal serrated adenocarcinoma

Serrated adenocarcinoma (SAC) is a recently defined subtype of colorectal carcinoma (CRC). However, in cases where an adjacent serrated adenoma is absent and the differentiation is poor, the diagnosis of SAC can be challenging. BRAF V600E mutation is a characteristic molecular change for the serrated route, but the utility of the newly described BRAF V600E-specific immunohistochemistry in the recognition of SAC is unclear. In this study, we conducted immunohistochemical determination of BRAF V600E mutation and correlated the results to BRAF mutation status and the histological features of SAC in a cohort of 147 CRC patients. There were 13 (8.8xa0%) BRAF-mutated CRCs confirmed by DNA sequencing. The sensitivity of immunohistochemistry in detecting BRAF V600E mutation was 100xa0% (13/13) and the specificity was 99.3xa0% (133/134). Three evaluators independently analyzed the immunohistochemical sections and the correlation between all the evaluators was perfect (κu2009=u20091). In histologic examination, 33 (22.4xa0%) of the CRCs were classified as SACs. Twelve of 13 (92.3xa0%) BRAF-mutated CRCs were evaluated to represent serrated type growth pattern. One of 13 (7.7xa0%) showed poor differentiation not enabling convincing classification. In conclusion, we found immunohistochemistry to be accurate in the detection of the BRAF V600E mutation, with potential applications in the recognition of the BRAF-mutated SACs. Especially in cases where the adjacent adenoma is absent and the tumor is poorly differentiated, BRAF immunohistochemistry could be utilized as an aid to detect SACs.

Collagen XVII expression correlates with the invasion and metastasis of colorectal cancer

Collagen XVII has a well-established role as an adhesion molecule and a cell surface receptor located in the type I hemidesmosome of stratified epithelia. Its ectodomain is constitutively shed from the cell surface and suggested to regulate the adhesion, migration, and signaling of cutaneous epithelial cells. Collagen XVII was not previously thought to be expressed by colon epithelial cells. Immunohistochemical analysis of tissue microarray samples of 141 cases of colorectal carcinoma showed that collagen XVII is expressed in normal human colonic mucosa and colorectal carcinoma. In colorectal carcinoma, increased collagen XVII expression was significantly associated with higher TNM stage. It also correlated with infiltrative growth pattern and tumor budding as well as lymph node and distant metastasis. Increased collagen XVII expression was associated with decreased disease-free and cancer-specific survival. Immunofluorescence staining of collagen XVII and its well-known binding partner laminin γ2 chain demonstrated a partial colocalization in normal and tumor tissue. In vitro, the overexpression of murine collagen XVII promoted the invasion of CaCo-2 colon carcinoma cells through Matrigel (BD Biosciences; Bedford, MA). To conclude, this study reports for the first time the expression of collagen XVII in colon epithelium and the association of increased collagen XVII immunoexpression with poor outcome in colorectal carcinoma.

Clinical impact and network of determinants of tumour necrosis in colorectal cancer

Background:The disease outcome in colorectal cancer (CRC) can vary in a wide range within the same tumour stage. The aim of this study was to clarify the prognostic value and the determinants of tumour necrosis in CRC.Methods:The areal proportion (%) of tumour tissue showing coagulative necrosis was evaluated in a cohort of 147 CRC patients and correlated with basic clinicopathological characteristics, microvascular density (MVD), cell proliferation rate, KRAS and BRAF mutations, and survival. To validate the prognostic significance of tumour necrosis, an independent cohort of 418 CRC patients was analysed.Results:Tumour necrosis positively correlated with tumour stage (P=8.5E−4)—especially with T class (4.0E−6)—and inversely correlated with serrated histology (P=0.014), but did not significantly associate with cell proliferation rate, MVD, and KRAS or BRAF mutation. Abundant (10% or more) tumour necrosis associated with worse disease-free survival independent of stage and other biological or clinicopathological characteristics in both cohorts, and the adverse effect was directly related to its extent. High CD105 MVD was also a stage independent marker for worse disease-free survival.Conclusions:Tumour necrosis percentage is a relevant histomorphological prognostic indicator in CRC. More studies are needed to disclose the mechanisms of tumour necrosis.

Isotretinoin treatment reduces acne lesions but not directly lesional acne inflammation.

Hanna-Leena Kelh€ al€ a, Nanna Fyhrquist, Riitta Palatsi, Sari Lehtim€aki, Juha P. V€ayrynen, Minna E. Kubin, Matti Kallioinen, Harri Alenius, Kaisa Tasanen and Antti Lauerma PEDEGO Research Center, Department of Dermatology, University of Oulu, Oulu, Finland; Medical Research Center Oulu (MRC Oulu), Oulu University Hospital, Oulu, Finland; Unit for Immunotoxicology, Finnish Institute of Occupational Health, Helsinki, Finland; Department of Dermatology, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland; Department of Pathology, University of Oulu and Oulu University Hospital, Oulu, Finland Correspondence: Hanna-Leena Kelh€al€a, M.D., Department of Dermatology, University of Oulu, Oulu University Hospital, P.B. 20, FIN-90029 Oulu, Finland, Tel.: +358 8 315 3508, e-mail: hanna-leena.kelhala@ppshp.fi

Significant role of collagen XVII and integrin β4 in migration and invasion of the less aggressive squamous cell carcinoma cells

Collagen XVII and integrin α6β4 have well-established roles as epithelial adhesion molecules. Their binding partner laminin 332 as well as integrin α6β4 are largely recognized to promote invasion and metastasis in various cancers, and collagen XVII is essential for the survival of colon and lung cancer stem cells. We have studied the expression of laminin γ2, collagen XVII and integrin β4 in tissue microarray samples of squamous cell carcinoma (SCC) and its precursors, actinic keratosis and Bowen’s disease. The expression of laminin γ2 was highest in SCC samples, whereas the expression of collagen XVII and integrin β4 varied greatly in SCC and its precursors. Collagen XVII and integrin β4 were also expressed in SCC cell lines. Virus-mediated RNAi knockdown of collagen XVII and integrin β4 reduced the migration of less aggressive SCC-25 cells in horizontal scratch wound healing assay. Additionally, in a 3D organotypic myoma invasion assay the loss of collagen XVII or integrin β4 suppressed equally the migration and invasion of SCC-25 cells whereas there was no effect on the most aggressive HSC-3 cells. Variable expression patterns and results in migration and invasion assays suggest that collagen XVII and integrin β4 contribute to SCC tumorigenesis.

Clinical efficiency of topical calcipotriol/betamethasone treatment in psoriasis relies on suppression of the inflammatory TNFα – IL- 23 – IL-17 axis

The effects of topical calcipotriol/betamethasone combination therapy and betamethasone monotherapy on inflammatory T-cell numbers and molecular markers were compared in patients with psoriasis. Combination therapy down-regulated the expression of tumour necrosis factor (TNF)-α, interleukin (IL)-23A, IL-17A, S100A7, CCL-20 and interferon (IFN)-γ in skin and TNF-α, IL-6, IL-23A, T-bet and IFN-γ in peripheral blood mononuclear cells (PBMCs). Betamethasone monotherapy had less effect. Expression of FoxP3 in both skin and PBMCs was down-regulated by calcipotriol/betamethasone, but not by betamethasone. Immunohistochemical analysis revealed that calcipotriol/betamethasone reduced the numbers of CD4+ and CD8+ T cells and Tregs in psoriatic lesions more than betamethasone. Flow cytometric analyses demonstrated that calcipotriol/betamethasone decreased the numbers of circulating CD8+ T cells, Tregs, skin-homing Th17 memory cells and Th22 memory cells, while betamethasone had little or no effect. Glucocorticoid receptors GRα and GRß were expressed in psoriatic skin. In conclusion, calcipotriol increases the immunosuppressive power of betamethasone by suppressing the inflammatory TNF-α - IL-23 - IL-17 axis.

Glucocorticoid receptors GRα and GRβ are expressed in inflammatory dermatoses.

BackgroundGlucocorticoids (GC) are the most commonly used antiinflammatory drugs in dermatology. The actions of GCs are mediated by the glucocorticoid receptor (GR). Alternative splicing of GR mRNA gives rise to different isoforms, GRα and GRβ being the most important. GRβ antagonizes the activity of GRα and its up-regulation has been associated with glucocorticoid insensitivity in several non-cutaneous inflammatory diseases.MethodsUsing immunohistochemical stainings, we analyzed the expression of GRα and GRβ in lesional skin samples of patients with atopic dermatitis, lichen ruber planus, eczema nummulare and lichen simplex chronicus.We also conducted a study of 13 severe atopic patients to investigate the effect of prednisolone treatment on the expression of GR isoforms using quantitative PCR, western blot and immunohistochemical analysis.ResultsGRα and GRβ were expressed in atopic dermatitis, lichen ruber planus, eczema nummulare and lichen simplex chronicus. Our novel finding was that GRα is abundant in keratinocytes and cutaneous neutrophils. Nuclear staining of both GRα and GRβ was strongest in keratinocytes of patients with lichen ruber planus, whereas the least nuclear positivity was detected in keratinocytes of patients with atopic dermatitis. In severe atopic dermatitis GRα and GRβ were expressed in both peripheral blood mononuclear cells and the skin. The expression of GRα and GRβ varied during prednisolone therapy but the changes were not related to treatment response or GC insensitivity.ConclusionGRα and GRβ are expressed in inflammatory dermatoses. In severe atopic dermatitis the increased expression of GRβ mRNA is not connected to insensitivity against prednisolone treatment.

Expression of Glucocorticoid Receptors GRα and GRβ in Bullous Pemphigoid

First-line treatments of bullous pemphigoid (BP) are topical and systemic glucocorticoids (GC). The actions of GC are mediated by glucocorticoid receptors (GR), which exist in several isoforms, of which GRα and GRβ are the most important. In many inflammatory diseases, up-regulation of GRβ is associated with GC insensitivity. The aims of this study were to determine the expression of GRα and GRβ in patients with BP and to investigate the effect of prednisolone treatment on the expression of GR isoforms in BP. Quantitative real-time PCR (qPCR) analysis demonstrated that GR isoform mRNAs are expressed in peripheral blood mononuclear cells (PBMC) from patients with BP. Expression of GRα and GRβ protein was confirmed by immunohistochemical staining of BP skin biopsies and by Western blot analysis and flow cytometric analysis of PBMCs. During prednisolone treatment, GRα and GRβ expression varied markedly, but changes were not suitable as a clinical marker of GC sensitivity in patients with BP.

Decreased preoperative serum 25-Hydroxyvitamin D levels in colorectal cancer are associated with systemic inflammation and serrated morphology.

Deficiency of vitamin D is associated with increased risk of several types of cancer including colorectal cancer (CRC). However, factors contributing to low levels of 25-hydroxyvitamin D [25(OH)D] in CRC are not clear. Therefore, in this study serum 25(OH)D levels in 117 CRC patients and 86 controls were analyzed and correlated with the clinicopathological data including morphological subtype (serrated or conventional), quantity of tumor infiltrating immune cells, levels of systemic inflammatory markers, and disease outcome. We found that the patients had lower serum 25(OH)D levels compared to the controls. Interestingly, among the patients mismatch repair deficiency, serrated morphology, and high body mass index associated with lowest serum 25(OH)D levels. In addition, patients operated in summer or autumn had higher serum 25(OH)D levels. Furthermore, serum 25(OH)D levels inversely correlated with several systemic inflammatory markers, e.g. serum C reactive protein, but did not associate with prognosis. Mechanism leading to vitamin D deficiency in these patients are not clear but could be related to the effects of systemic inflammation. Longitudinal studies are warranted to assess vitamin D deficiency as a potential risk factor for serrated colorectal polyps and adenocarcinoma.