The IL-1R family member IL-33R mediates Fcε-receptor-I (FcεRI)-independent activation of mast cells leading to NF-κB activation and consequently the production of cytokines. IL-33 also induces the activation of MAPKs, such as p38. We aimed to define the relevance of the p38-targets, the MAPK-activated protein kinases 2 and 3 (MK2 and MK3) in IL-33-induced signaling and the resulting mast cell effector functions in vitro and in vivo. We demonstrate that the IL-33-induced IL-6 and IL-13 production strongly depends on the MK2/3-mediated activation of ERK1/2 and PI3K signaling. Furthermore, in the presence of the stem cell factors, IL-33 did induce an MK2/3-, ERK1/2- and PI3K-dependent production of TNF-α. In vivo, the loss of MK2/3 in mast cells decreased the IL-33-induced leukocyte recruitment and the resulting skin inflammation. Therefore, the MK2/3-dependent signaling in mast cells is essential to mediate IL-33-induced inflammatory responses. Thus, MK2/3 are potential therapeutic targets for suppression of IL-33-induced inflammation skin diseases such as psoriasis.

The development of cervical cancer is frequently accompanied by the integration of human papillomaviruses (HPV) DNA into the host genome. Viral-cellular junction sequences, which arise in consequence, are highly tumor specific. By using these fragments as markers for tumor cell origin, we examined cervical cancer clonality in the context of intra-tumor heterogeneity. Moreover, we assessed the potential of these fragments as molecular tumor markers and analyzed their suitability for the detection of circulating tumor DNA in sera of cervical cancer patients. For intra-tumor heterogeneity analyses tumors of 8 patients with up to 5 integration sites per tumor were included. Tumor islands were micro-dissected from cryosections of several tissue blocks representing different regions of the tumor. Each micro-dissected tumor area served as template for a single junction-specific PCR. For the detection of circulating tumor-DNA (ctDNA) junction-specific PCR-assays were applied to sera of 21 patients. Samples were collected preoperatively and during the course of disease. In 7 of 8 tumors the integration site(s) were shown to be homogenously distributed throughout different tumor regions. Only one tumor displayed intra-tumor heterogeneity. In 5 of 21 analyzed preoperative serum samples we specifically detected junction fragments. Junction-based detection of ctDNA was significantly associated with reduced recurrence-free survival. Our study provides evidence that HPV-DNA integration is as an early step in cervical carcinogenesis. Clonality with respect to HPV integration opens new perspectives for the application of viral-cellular junction sites as molecular biomarkers in a clinical setting such as disease monitoring.

Aim was to identify methylated genes with functional involvement in cisplatin‐resistance development of epithelial ovarian cancer (EOC). Genome‐wide analyses of hypermethylated CpG‐islands in resistant cell lines in combination with qRT‐PCR analyses were used to identify epigenetically silenced genes. EOC‐Type‐II tumors were analyzed for gene methylation and expression and TCGA data were interrogated in‐silico. Experiments revealed 37 commonly hypermethylated genes in resistant cells of which Tribbles 2 (TRIB2) showed the most pronounced downregulation on mRNA level and was characterized further. TRIB2 showed a reactivation after 5′‐Aza‐Cytidine treatment in resistant cells but a cisplatin‐dependent, prominent upregulation on mRNA level in sensitive cells, only. Re‐expression in resistant A2780 cells increased the sensitivity to cisplatin and other DNA‐damaging agents, but not taxanes. Contrary, knockdown of TRIB2 increased resistance to cisplatin in sensitive cells. TRIB2 was involved in the induction of a cisplatin‐dependent cell cycle arrest and apoptosis by influencing p21 and survivin expression. An increased Pt‐DNA‐adduct formation in TRIB2 re‐expressing cells did not translate in higher levels of dsDNA damage (yH2AX‐foci). Thus, TRIB2 is potentially involved in the signal transduction from nucleotide excision repair of intrastrand cross links. Importantly, patient stratification of two homogenous cohorts of EOC‐Type‐II patients from Jena (n = 38) and the TCGA (n = 149) by TRIB2 mRNA expression consistently revealed a significantly decreased PFS for patients with low TRIB2 levels (log‐rank p < 0.05). Tumors from resistant patients expressed the lowest levels of TRIB2. Downregulation of TRIB2 contributes to platin‐resistance and TRIB2 expression should be validated as prognostic and predictive marker for EOC.

Dysregulated apoptotic pathways are regarded as major reasons for chemoresistance development as a particular challenge in ovarian cancer therapy. In search of molecular factors affecting human ovarian cancer cell apoptosis and, consequently, patient survival, we examined tumors of 103 platinum‐/taxane‐treated ovarian cancer patients by mRNA‐array hybridization, qPCR, and immunohistochemistry. We identified high expression of crystallin αB (CRYAB), a proposed negative regulator of tumor necrosis factor‐related apoptosis inducing ligand (TRAIL)‐mediated apoptosis. By Kaplan Meier analysis, this factor turned out to be significantly associated with poor patient outcome [overall survival (OS) p = 0.001, recurrence‐free survival (RFS) p = 0.003]. Elevated hazard ratios (HR) were estimated with regard to OS (HR = 2.11, 95% CI 1.10–4.06) and RFS (HR = 1.92, 95% CI 1.07–3.47) in multivariable analyses. These associations were confirmed in independent, publicly available mRNA data comprising 431 patients for OS (p < 0.001) and 413 for RFS (p < 0.001)_. Our findings were validated by studying apoptotic events in cultured human ovarian cancer cells which were stably transfected to express elevated CRYAB levels. These data emphasized the crucial role of CRYAB in human ovarian cancer biology since TRAIL‐ as well as cisplatin‐induced apoptosis was significantly impaired as a function of enhanced CRYAB expression. Taken together, we identified CRYAB as an independent biomarker for unfavourable outcome of human ovarian cancer patients. Since TRAIL is currently tested as anti‐cancer drug and large proportions of the present patient cohort displayed low CRYAB levels in their tumors, CRYAB may enable the selection of patient subgroups benefiting most from TRAIL‐containing therapy.