Radiosensitive Hematopoietic Cells Determine the Extent of Skin Inflammation in Experimental Epidermolysis Bullosa Acquisita.

Animal models have enhanced our understanding of the pathogenesis of autoimmune diseases. For these models, genetically identical, inbred mice have commonly been used. Different inbred mouse strains, however, show a high variability in disease manifestation. Identifying the factors that influence this disease variability could provide unrecognized insights into pathogenesis. We established a novel Ab transfer-induced model of epidermolysis bullosa acquisita (EBA), an autoimmune disease characterized by (muco)-cutaneous blistering caused by anti-type VII collagen (COL7) autoantibodies. Blistering after anti-COL7 IgG (directed against the von Willebrand factor A-like domain 2) transfer showed clear variability among inbred mouse strains, that is, severe cutaneous blistering and inflammation in C57BL/6J and absence of skin lesions in MRL/MpJ mice. The transfer of anti-COL7 IgG into irradiated, EBA-resistant MRL/MpJ mice, rescued by transplantation with bone marrow from EBA-susceptible B6.AK-H2k mice, induced blistering. To the contrary, irradiated EBA-susceptible B6.AK-H2k mice that were rescued using MRL/MpJ bone marrow were devoid of blistering. In vitro, immune complex activation of neutrophils from C57BL/6J or MRL/MpJ mice showed an impaired reactive oxygen species release from the latter, whereas no differences were observed after PMA activation. This finding was paralleled by divergent expression profiles of immune complex-activated neutrophils from either C57BL/6J or MRL/MpJ mice. Collectively, we demonstrate that radiosensitive cells determine the varying extent of skin inflammation and blistering in the end-stage effector phase of EBA.

Ionizing radiation induces a motile phenotype in human carcinoma cells in vitro through hyperactivation of the TGF-beta signaling pathway.

Radiotherapy, a major treatment modality against cancer, can lead to secondary malignancies but it is uncertain as to whether tumor cells that survive ionizing radiation (IR) treatment undergo epithelial-mesenchymal transition (EMT) and eventually become invasive or metastatic. Here, we have tested the hypothesis that the application of IR (10 MeV photon beams, 2-20 Gy) to lung and pancreatic carcinoma cells induces a migratory/invasive phenotype in these cells by hyperactivation of TGF-ß and/or activin signaling. In accordance with this assumption, IR induced gene expression patterns and migratory responses consistent with an EMT phenotype. Moreover, in A549 cells, IR triggered the synthesis and secretion of both TGF-ß1 and activin A as well as activation of intracellular TGF-ß/activin signaling as evidenced by Smad phosphorylation and transcriptional activation of a TGF-ß-responsive reporter gene. These responses were sensitive to SB431542, an inhibitor of type I receptors for TGF-ß and activin. Likewise, specific antibody-mediated neutralization of soluble TGF-ß, or dominant-negative inhibition of the TGF-ß receptors, but not the activin type I receptor, alleviated IR-induced cell migration. Moreover, the TGF-ß-specific approaches also blocked IR-dependent TGF-ß1 secretion, Smad phosphorylation, and reporter gene activity, collectively indicating that autocrine production of TGF-ß(s) and subsequent activation of TGF-ß rather than activin signaling drives these changes. IR strongly sensitized cells to further increase their migration in response to recombinant TGF-ß1 and this was accompanied by upregulation of TGF-ß receptor expression. Our data raise the possibility that hyperactivation of TGF-ß signaling during radiotherapy contributes to EMT-associated changes like metastasis, cancer stem cell formation and chemoresistance of tumor cells.

Macrophage Migration Inhibitory Factor (MIF) Drives Murine Psoriasiform Dermatitis.

The immunomodulator Macrophage Migration Inhibitory Factor (MIF) exerts pleiotropic immunomodulatory activities and has been implicated in the pathogenesis of diverse inflammatory diseases. Expression levels of MIF are also significantly elevated in the skin and serum of psoriasis patients, but the pathogenic significance of MIF in psoriasis is unknown. We have therefore addressed the role of MIF in two mouse models of psoriasis, namely in the imiquimod-induced psoriasiform dermatitis (IIPD) and the IL-23-induced dermatitis model. Daily treatment with Aldara™ cream, containing imiquimod, markedly increased the abundance of MIF in the skin and generated a cellular skin expression pattern of MIF closely resembling that in human plaque psoriasis. Deficiency in MIF significantly alleviated IIPD. On the clinical level, all hallmarks of psoriasiform dermatitis, including erythema, skin infiltration, and desquamation were reduced in Mif-/- mice. On the histopathological level, MIF deficiency decreased keratinocyte hyperproliferation, inflammatory cell infiltration, specifically with respect to monocyte-derived cells, and dermal angiogenesis, suggesting that MIF may be involved in the pathogenesis of psoriasiform dermatitis through several mechanisms. Similarly, MIF deficiency also significantly reduced disease in the IL-23-induced dermatitis model, suggesting that MIF is involved in the pathogenic pathways activated by IL-23 and required to achieve full-blown psoriasiform dermatitis. Collectively, our results lend support to a possible disease-promoting role of MIF in psoriasis, which should be further investigated.

The Leukotriene B4 and its Receptor BLT1 Act as Critical Drivers of Neutrophil Recruitment in Murine Bullous Pemphigoid-Like Epidermolysis Bullosa Acquisita.

Recruitment of neutrophils and eosinophils into the skin is a hallmark of pemphigoid diseases. The molecular cues regulating granulocyte recruitment into the skin and the individual contributions of neutrophils and eosinophils to pemphigoid diseases are, however, poorly understood. The lipid mediator leukotriene B4 (LTB4) is a potent granulocyte chemoattractant and is abundant in the skin blister fluid of bullous pemphigoid (BP) patients, but its pathogenic significance is unknown. Using mouse models of BP-like epidermolysis bullosa acquisita and of BP, we show that LTB4 and its receptor BLT1 act as critical drivers of neutrophil entry into the skin upon antibody deposition at the dermal-epidermal junction. Mice deficient in 5-lipoxygenase, a key enzyme in LTB4 biosynthesis, or in BLT1 exhibited dramatic resistance to neutrophil recruitment and, consequently, skin inflammation. Accordingly, liquid chromatography-mass spectrometry, used to comprehensively profile lipid mediator generation in the first 48 hours after antibody deposition, showed a pronounced parallel increase in LTB4 and in neutrophils in the skin. Subsequent mechanistic studies in BP-like epidermolysis bullosa acquisita uncovered that neutrophils are necessary for skin inflammation, whereas eosinophils are dispensable, thus identifying neutrophils as major culprits of blister formation. Our results highlight LTB4/BLT1 as absolutely critical drivers of murine pemphigoid disease-like skin inflammation.

Radiation Therapy for Metastatic Spinal Cord Compression in Patients with Hepatocellular Carcinoma.

AIM: This is the first study to investigate patients with metastatic spinal cord compression (MSCC) from hepatocellular carcinoma (HCC). PATIENTS AND METHODS: Eight patients were analyzed with regard to survival and motor dysfunction. RESULTS: Out of seven factors (age, affected vertebrae, ambulatory status, bone lesions, other distant metastases, time developing motor dysfunction, performance score) ambulatory status (p=0.005) and distant metastases (p=0.032) had a significant influence on survival. Both factors were used as a predictive tool (points: not ambulatory 0, ambulatory 1, distant metastases 0, no distant metastases 1). Total scores were 0, 1 or 2 points. Three-month survival rates were 0%, 67% and 100%, six-month survival rates 0%, 0% and 100%. Progression of motor dysfunction was prevented in 63% of patients; time developing motor deficits showed a trend (p=0.08). CONCLUSION: Many patients with MSCC from HCC have a short survival, which can be predicted with a new tool. Radiation therapy can stop progression of motor dysfunction.

Estimation of the Six-month Survival Probability After Radiosurgery for Brain Metastases from Kidney Cancer.

AIM: To generate an overall survival score for patients with kidney cancer who underwent radiosurgery for brain metastases. PATIENTS AND METHODS: Thirty-six patients who received radiosurgery alone for 1-3 brain metastases from kidney cancer were included. On multivariate analysis of a preceding study of such patients, Karnofsky performance score (KPS) and extracranial spread were significantly associated with overall survival and formed the basis for this score. For each patient, the prognostic score was derived from adding the points of KPS and extracranial spread resulting in a score of 9, 12, 15 or 18 points. RESULTS: Six-month overall survival rates were 13% for patients with 9 points, 80% for those with 12 points, 79% for those with 15 points and 100% for those with 18 points, respectively. Three groups of patients were defined with scores of 9, 12-15 and 18 points. Six-month overall survival rates were 13%, 79% and 100%, respectively (p=0.004). CONCLUSION: This new score facilitates personalized treatment decisions for patients with kidney cancer with very few brain metastases.

Predicting the Risk of New Cerebral Lesions After Stereotactic Radiosurgery (SRS) for Brain Metastases from Breast Cancer.

AIM: To generate a tool that estimates the probability of developing new cerebral metastases after stereotactic radiosurgery (SRS) in breast cancer patients. PATIENTS AND METHODS: SRS dose plus seven characteristics (age, performance score, number of cerebral metastases, maximum diameter of all metastases, location of metastases, extra-cerebral spread and time from breast cancer diagnosis until SRS) were analyzed regarding their ability to predict the probability of new cerebral metastases development following SRS. For those characteristics deemed significant, points of 0 (higher risk of new lesions) or 1 (lower risk) were given. Scores were generated by adding the points of significant characteristics. RESULTS: Performance score (p=0.013) and maximum diameter of all metastases (p=0.022) were associated with development of subsequent brain metastases. Two groups were created, 0-1 and 2 points. Freedom from new cerebral metastases rates were 27% and 92%, respectively, at 15 months (p=0.003). CONCLUSION: This tool helps select breast cancer with few cerebral metastases receiving SRS who may benefit from additional whole-brain irradiation.

A New Predictive Tool for Optimization of the Treatment of Brain Metastases from Colorectal Cancer After Stereotactic Radiosurgery.

AIM: To develop a predictive tool for survival after stereotactic radiosurgery of brain metastases from colorectal cancer. PATIENTS AND METHODS: Out of nine factors analyzed for survival, those showing significance (p<0.05) or a trend (p≤0.06) were included. For each factor, 0 (worse survival) or 1 (better survival) point was assigned. Total scores represented the sum of the factor scores. RESULTS: Performance status (p=0.010) and interval from diagnosis of colorectal cancer until radiosurgery (p=0.026) achieved significance, extracranial metastases showed a trend (p=0.06). These factors were included in the tool. Total scores were 0-3 points. Six-month survival rates were 17% for patients with 0, 25% for those with 1, 67% for those with 2 and 100% for those with 3 points; 12-month rates were 0%, 0%, 33% and 67%, respectively. Two groups were created: 0-1 and 2-3 points. Six- and 12-month survival rates were 20% vs. 78% and 0% vs. 44% (p=0.002), respectively. CONCLUSION: This tool helps optimize the treatment of patients after stereotactic radiosurgery for brain metastases from colorectal cancer.

Defining the Optimal Dose of Stereotactic Radiosurgery for Treating Cerebral Metastases in Elderly Patients.

BACKGROUND/AIM: In oncology, elderly people are a separate group of patients requiring special consideration. This applies to the treatment of cerebral metastases as well. The present study focused on elderly patients receiving stereotactic radiosurgery (SRS) for few cerebral lesions. PATIENTS AND METHODS: In 95 patients aged ≥65 years, two SRS doses, 16-18 Gy (n=44) and 20 Gy (n=51), were compared regarding outcomes of SRS. RESULTS: The overall intracerebral control rates at 12 months were 30% after 16-18 Gy and 45% after 20 Gy (p=0.53). Twelve-month rates of freedom from new intracerebral lesions were 41% and 52%, respectively (p=0.63). Twelve-month local control rates of the irradiated lesions were 55% and 81%, respectively (p=0.069). Overall survival rates at 12 months were 29% and 31%, respectively (p=0.67). CONCLUSION: SRS with 16-18 Gy was not significantly inferior to SRS with 20 Gy in elderly patients with few cerebral metastases.

Comparison of two dose levels of stereotactic radiosurgery for 1-3 brain metastases from non-small cell lung cancer.

AIM: Two dose groups of patients treated with stereotactic radiosurgery (SRS) alone for 1-3 brain metastases from non-small cell lung cancer (NSCLC) were compared for outcomes. PATIENTS AND METHODS: Based on the SRS dose administered to the margins of the brain lesions, 46 patients were assigned to groups treated with 15-18 Gy (n=13) or with 20 Gy (n=33). Seven additional factors were investigated: age (≤ 58 vs. ≥ 59 years), gender, Karnofsky performance score (KPS 70-80 vs. 90-100), number of brain metastases (1 vs. 2-3), histology (adenocarcinoma vs. other) extracerebral metastases and interval from NSCLC diagnosis to SRS (≤ 6 vs. >6 months). RESULTS: Local control rates for 15-18-Gy and 20-Gy groups were 75% and 92% at one year (p=0.043). SRS dose was significant on multivariate analysis (p=0.030). SRS dose was not associated with freedom from new brain metastases (p=0.24) or survival (p=0.37). CONCLUSION: SRS with 20 Gy resulted in better control of the irradiated metastases than 15-18 Gy did.