Heterogeneity of chromatin modifications in testicular spermatocytic seminoma point toward an epigenetically unstable phenotype.

Testicular spermatocytic seminoma (SS) is a rare tumor type predominantly found in elderly men. It is thought to originate from spermatogonia and shows cytological and genetic heterogeneity. In this study, we performed for the first time a comprehensive analysis of epigenetic modifications in a series of 36 SS samples. We assessed by immunohistochemistry tumor DNA methylation levels, the expression of methyltransferases DNMT3A, DNMT3B and DNMT3L as well as levels of histone modifications H3K9me2, H3K27me3, H3K4me1, H3K4me2/3, H3K9ac, and H2A.Z. We did not identify any epigenetic marks that matched the pattern of the supposed cell-of-origin, the spermatogonia, and found no correlation between specific marks and the size of the SS cells. The emerging epigenetic picture of SS is a heterogeneous "salt-and-pepper"-like pattern, with neighboring cells displaying very variable levels of epigenetic marks. We conclude that SS cells display apparent epigenetic heterogeneity and instability, with loss of the organized manner typical for normal germ cell maturation in the adult testis, likely due to the lack of regulatory signals from the absent somatic cell niche.

Halting angiogenesis by non-viral somatic gene therapy alleviates psoriasis and murine psoriasiform skin lesions.

Dysregulated angiogenesis is a hallmark of chronic inflammatory diseases, including psoriasis, a common skin disorder that affects approximately 2% of the population. Studying both human psoriasis in 2 complementary xenotransplantation models and psoriasis-like skin lesions in transgenic mice with epidermal expression of human TGF-ß1, we have demonstrated that antiangiogenic non-viral somatic gene therapy reduces the cutaneous microvasculature and alleviates chronic inflammatory skin disorders. Transient muscular expression of the recombinant disintegrin domain (RDD) of metargidin (also known as ADAM-15) by in vivo electroporation reduced cutaneous angiogenesis and vascularization in all 3 models. As demonstrated using red fluorescent protein-coupled RDD, the treatment resulted in muscular expression of the gene product and its deposition within the cutaneous hyperangiogenic connective tissue. High-resolution ultrasound revealed reduced cutaneous blood flow in vivo after electroporation with RDD but not with control plasmids. In addition, angiogenesis- and inflammation-related molecular markers, keratinocyte proliferation, epidermal thickness, and clinical disease scores were downregulated in all models. Thus, non-viral antiangiogenic gene therapy can alleviate psoriasis and may do so in other angiogenesis-related inflammatory skin disorders.

OCT4 and downstream factors are expressed in human somatic urogenital epithelia and in culture of epididymal spheres.

The transcription factor OCT4 plays a crucial role in the earliest differentiation of the mammalian embryo and in self-renewal of embryonic stem cells. However, it remains controversial whether this gene is also expressed in somatic tissues. Here, we use a combination of RT-PCR on whole and microdissected tissues, in situ hybridization, immunohistochemistry and western blotting to show that OCT4 and SOX2 together with downstream targets, UTF1 and REX1/ZFP42, are expressed in the human male urogenital tract. We further support these results by the analysis of DNA methylation of a region in the OCT4 promoter. In culture, human primary epididymal cells formed spheres that continued to express the investigated genes for at least 20 days. Transcriptomic analysis of cultured cells showed up-regulation of CD29, CD44 and CD133 that are normally associated with sphere-forming cancer stem cells. Furthermore, stimulation with retinoic acid resulted in down-regulation of OCT4 expression, however, without multilineage differentiation. Our results show that OCT4 and associated genes are expressed in somatic epithelial cells from the urogenital tract and that these cells can form spheres, a general marker of stem cell behaviour.

Significance of the S100A4 protein in psoriasis.

The S100A4 protein is reported as a pivotal player in the tumor microenvironment with a metastasis-promoting function. Moreover, the upregulation of S100A4 is found in other non-malignant human disorders as cardiac and pulmonary systems and rheumatoid arthritis. In this study, we investigated the expression and significance of S100A4 in psoriasis. We found significant upregulation of S100A4 in the dermis of psoriatic skin compared with normal skin. This pattern of S100A4 expression differs considerably from that of other S100 proteins, S100A7 and S100A8/9, with predominant expression in the epidermis of psoriasis. Furthermore, we revealed a massive release of the biologically active forms of S100A4 from psoriatic skin. Interestingly, we found stabilization (increase) of p53 in the basal layer of epidermis in close proximity to cells expressing S100A4. To examine the possible implication of S100A4 in the pathogenesis of psoriasis, we analyzed the effect of S100A4 blocking antibodies in a human psoriasis xenograft SCID mouse model and observed a significant reduction of the epidermal thickness and impairment in cell proliferation and dermal vascularization. In conclusion, we showed strong upregulation and release of S100A4 in the upper dermis of psoriatic skin and found evidence indicating that S100A4 might actively contribute to the pathogenesis of psoriasis.

Presumed pluripotency markers UTF-1 and REX-1 are expressed in human adult testes and germ cell neoplasms.

BACKGROUND: UTF-1 and REX-1/ZFP42 are transcription factors involved in pluripotency. Because of phenotypic similarities between pluripotent embryonic stem cells and testicular germ cell tumours (TGCT) and the derivation of pluripotent cells from testes, we investigated the expression of UTF-1 and REX-1 during human gonadal development and in TGCT. METHODS: Expression of UTF-1 and REX-1 was studied in 52 specimens from human gonadal development and in 86 samples from TGCT. RESULTS: UTF-1 and REX-1 were expressed throughout male gonadal development. In the mature testis, UTF-1 was expressed in spermatogonia, whereas REX-1 was expressed in meiotic cells and, together with OCT-3/4, in primary oocytes. Both UTF-1 and REX-1 were expressed in testicular carcinoma in situ and in TGCT. Contrarily to REX-1, UTF-1 was expressed in all spermatocytic seminomas. CONCLUSIONS: Unlike other pluripotency markers NANOG and OCT-3/4, UTF-1 and REX-1 are expressed throughout human testes development. The expression pattern indicated that UTF-1 plays a possible role in spermatogonial self-renewal, whereas expression of REX-1 in meiotic cells from both testes and ovary indicate a role in meiosis. UFT-1 and REX-1 are expressed in TGCT and the high abundance of UTF-1 in spermatocytic seminomas is consistent with the hypothesis that this tumour type originates from spermatogonia.