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We studied DNA methylation profiles in four different cell populations from a unique constellation of monozygotic triplets in whom two had developed Hodgkin Lymphoma (HL). We detected shared differences in DNA methylation signatures when comparing the two HL-affected triplets with the non-affected triplet. The differences were observed in naïve B-cells and marginal zone-like B-cells. DNA methylation differences were also detected when comparing each of the HL-affected triplets against each other. Even though we cannot determine whether treatment and/or disease triggered the observed differences, we believe our data are important on behalf of forthcoming studies, and that it might provide important clues for a better understanding of HL pathogenesis.

Larvae of the Northern pine processionary moth (Thaumetopoea pinivora, TP) carry microscopic needles (setae), which by penetrating skin and mucous membranes, may cause inflammatory/immune derived symptoms in man. In the present study the stimulatory effects of setae on human blood lymphocytes in vitro was investigated. Blood mononuclear cells were separated from venous blood or buffy coat of ten healthy individuals, six previously exposed to setae and four with no known exposure. Lymphoproliferation was measured as uptake of 3H-thymidine. Setae were prepared from TP larvae. Setae and saline setae extracts stimulated proliferation of T-lymphocytes in the presence of monocytic cells. Stimulation was pronounced in cells from persons who had been exposed to setae, and weak in cells from non-exposed donors. Chitin also induced lymphocyte proliferation in most donors, but to a lesser extent and independently of donor's previous exposure to setae. In conclusion, setae contain molecules that in the presence of monocytes activate human T-lymphocytes to proliferation. The antigenic nature of stimulatory molecules was supported by the significantly stronger lymphocyte response in persons previously exposed to setae than in non-exposed donors. The nature of such molecules remains to be defined.

Arachidonate 15-lipoxygenase-1 (ALOX15) oxygenates polyunsaturated fatty acids and bio-membranes, generating multiple lipid signalling mediators involved in inflammation. Several lines of evidence indicate that ALOX15 activation in the respiratory tract contributes to asthma progression. Recent experimental data reveals that histone modification at the promoter plays a critical role in ALOX15 gene transcription. In the present study, we examined the status of histone H3 trimethyl-lysine 27 (H3K27me3) at the ALOX15 promoter by chromatin immunoprecipitation assay in human lung epithelial carcinoma A549 cells incubated with or without interleukin (IL)-4. We identified demethylation of H3K27me3 at the ALOX15 promoter after IL-4 treatment. Furthermore, we found that the H3K27me2/3-specific demethylase, ubiquitously transcribed tetratricopeptide repeat, X chromosome (UTX), mediates the H3K27me3 demethylation during ALOX15 transcriptional activation. When UTX expression was knocked down using siRNA, IL-4-mediated H3K27me3 demethylation and ALOX15 induction were significantly attenuated. The critical role of UTX in ALOX15 expression was confirmed in human monocytes and the Hodgkin lymphoma (HL) cell line L1236, but was in these cells not related to H3K27me3-demethylase activity. These results demonstrate that UTX is implicated in IL-4 mediated transcriptional activation of the ALOX15 gene.

15-Lipoxygenase-1 (15-LOX-1) oxidizes polyunsaturated fatty acids to a rich spectrum of biologically active metabolites and is implicated in physiological membrane remodelling, inflammation and apoptosis. Its deregulation is involved in the pathogenesis of diverse cancer and immune diseases. Recent experimental evidence reveals that dynamic histone methylation/demethylation mediated by histone methyltransferases and demethylases plays a critical role in regulation of chromatin remodelling and gene expression. In the present study, we compared the histone 3 lysine 4 (H3-K4) methylation status of the 15-LOX-1 promoter region of the two Hodgkin lymphoma (HL) cell lines L1236 and L428 with abundant and undetectable 15-LOX-1 expression, respectively. We identified a potential role of H3-K4 methylation in positive regulation of 15-LOX-1 transcription. Furthermore, we found that histone methyltransferase SMYD3 inhibition reduced 15-LOX-1 expression by decreasing promoter activity in L1236 cells. SMYD3 knock down in these cells abolished di-/trimethylation of H3-K4, attenuated the occupancy by the transactivator STAT6, and led to diminished histone H3 acetylation at the 15-LOX-1 promoter. In contrast, inhibition of SMCX, a JmjC-domain-containing H3-K4 tri-demethylase, upregulated 15-LOX-1 expression through induction of H3-K4 trimethylation, histone acetylation and STAT6 recruitment at the 15-LOX-1 promoter in L428 cells. In addition, we observed strong SMYD3 expression in the prostate cancer cell line LNCaP and its inhibition led to decreased 15-LOX-1 expression. Taken together, our data suggest that regulation of histone methylation/demethylation at the 15-LOX-1 promoter is important in 15-LOX-1 expression.

The therapeutic landscape in the treatment of advanced/metastatic renal cell cancer has evolved over the last 2 years with the advent of immune checkpoint inhibitors. In 2018 and 2019, marketing authorisations valid throughout the European Union were issued for nivolumab and ipilimumab dual checkpoint inhibition and pembrolizumab or avelumab in combination with the tyrosine kinase inhibitor axitinib. These applications presented numerous regulatory challenges.In this paper, we summarise the main regulatory considerations, originating from the assessment of the dossiers submitted from the applicants for the three combinations. The regulatory issues are grouped in four sections: clinical pharmacology, efficacy, biomarkers and safety. In each section, we describe the issues raised during the regulatory evaluation performed by the Committee for Medicinal Products for Human Use (CHMP) assessors. The CHMP assessments determine whether the medicines concerned meet the necessary quality, safety and efficacy requirements, and whether the benefit–risk balance is positive.In summary, although the overall benefit–risk was considered positive for the three combinations, the immaturity of the outcome data and the absence of long-term safety data remain issues to be addressed. Postauthorisation efficacy studies have been required to confirm the effects of the new combinations.