Anti-KRT18 monoclonal antibody, clone EB-8 [Biotin]

WNT/beta-catenin signaling has been described as a crucial regulator of embryonic stem cells and embryogenesis. However, little is known on its role during human preimplantation embryo development, besides the RNA expression of its multiple players. In this study, we performed beta-catenin loss- and gain-of-function studies on human preimplantation embryos by adding either Cardamonin or GSK3 inhibitor, 1-Azakenpaullone, to the embryo culture medium from the cleavage until blastocyst stages (Days 3-5/6). beta-Catenin was displayed in the cortical region underneath the membrane during all stages, but it only showed nuclear localization at cleavage stages after stabilization with 1-Azakenpaullone. We did not observe any effects on the inner cell mass markers POU5F1,SALL4 in these functional experiments. However, both beta-catenin degradation and stabilization caused inhibition of the trophectoderm (TE) fate, illustrated by KRT18 and GATA3 RNA, and CDX2 protein expression. Based on the TE-specific WNT3 protein expression in blastocysts, we postulated that this protein may be an upstream regulator for the observed membrane beta-catenin function. The addition of either WNT3 or 1-Azakenpaullone to the culture medium promoted EOMES expression specific for trophoblast development. In both studies, the canonical WNT pathway target gene, TCF1, was not affected. Therefore, we conclude that WNT3 and membrane-associated beta-catenin promote progenitor trophoblast development in human blastocysts. These results have important implications in assisted reproduction and stem cell biology.

Background The most efficient treatment for cutaneous melanoma is surgical excision in its early stage, which involves an accurate differentiation between melanoma and atypical nevi. Objectives The aim of this study was to investigate the expression of GDF15, CYR61, KRT18 and BCL-2 in cutaneous melanoma, atypical nevi and common nevi and to assess their possible role in differentiating malignant and benign lesions. Material and Methods Tissues samples from 13 invasive cutaneous melanomas, 11 dysplastic nevi and 14 common nevi as well as ten normal skin tissue samples were used for gene expression analysis. Light Cycler 480 (Roche Technologies) and Delta Delta Ct methodwas used to evaluate the expression of genes of interest. Results Gene CYR 61 proved to be down-regulated in cutaneous melanoma and common melanocytic nevi and up-regulated in dysplastic melanocytic nevi. GDF15 expression is progressively up-regulated from common nevi to dysplastic nevi and melanoma. KRT18 is down-regulated in common nevi and melanoma, and is slightly up-regulated in dysplastic nevi. BCL2 expression is progressively down-regulated from common nevi to dysplastic nevi and melanoma. Conclusions GDF15 could represent an important factor for melanoma progression and for differential diagnosis. CYR61 seems to be an early marker of neoplasia, but its capacity to distinguish benign lesions from early malignant ones has to be tested on larger studies that also include in situ lesions. BCL2 does not seem to specifically contribute to differentiating benign lesions from malignant ones. KRT 18 could play a role in cell proliferation and distinguishing typical lesions from dysplastic ones.