Tumor-associated copy number changes in the circulation of patients with prostate cancer identified through whole-genome sequencing

Background Patients with prostate cancer may present with metastatic or recurrent disease despite initial curative treatment. The propensity of metastatic prostate cancer to spread to the bone has limited repeated sampling of tumor deposits. Hence, considerably less is understood about this lethal metastatic disease, as it is not commonly studied. Here we explored whole-genome sequencing of plasma DNA to scan the tumor genomes of these patients non-invasively. Methods We wanted to make whole-genome analysis from plasma DNA amenable to clinical routine applications and developed an approach based on a benchtop high-throughput platform, that is, Illuminas MiSeq instrument. We performed whole-genome sequencing from plasma at a shallow sequencing depth to establish a genome-wide copy number profile of the tumor at low costs within 2 days. In parallel, we sequenced a panel of 55 high-interest genes and 38 introns with frequent fusion breakpoints such as the TMPRSS2-ERG fusion with high coverage. After intensive testing of our approach with samples from 25 individuals without cancer we analyzed 13 plasma samples derived from five patients with castration resistant (CRPC) and four patients with castration sensitive prostate cancer (CSPC). Results The genome-wide profiling in the plasma of our patients revealed multiple copy number aberrations including those previously reported in prostate tumors, such as losses in 8p and gains in 8q. High-level copy number gains in the AR locus were observed in patients with CRPC but not with CSPC disease. We identified the TMPRSS2-ERG rearrangement associated 3-Mbp deletion on chromosome 21 and found corresponding fusion plasma fragments in these cases. In an index case multiregional sequencing of the primary tumor identified different copy number changes in each sector, suggesting multifocal disease. Our plasma analyses of this index case, performed 13 years after resection of the primary tumor, revealed novel chromosomal rearrangements, which were stable in serial plasma analyses over a 9-month period, which is consistent with the presence of one metastatic clone. Conclusions The genomic landscape of prostate cancer can be established by non-invasive means from plasma DNA. Our approach provides specific genomic signatures within 2 days which may therefore serve as 'liquid biopsy'

BMP7 aberrantly induced in the psoriatic epidermis instructs inflammation-associated Langerhans cells.

BACKGROUND Epidermal hyperplasia represents a morphologic hallmark of psoriatic skin lesions. Langerhans cells (LCs) in the psoriatic epidermis engage with keratinocytes (KCs) in tight physical interactions; moreover, they induce T cell-mediated immune responses critical to psoriasis. OBJECTIVE Epidermal factors in psoriasis pathogenesis remain poorly understood. METHODS We phenotypically characterized BMP7-LCs vs. TGF-β1-LCs and analyzed their functional properties using flow cytometry, cell kinetic studies, co-culture with CD4 T-cells and cytokine measurements. Furthermore, immunohistology of healthy and psoriatic skin was performed. Additionally, in vivo experiments with Junf/fJunBf/fK5creER mice were carried out to assess the role of BMP signaling in psoriatic skin inflammation. RESULTS Here we identified a KC-derived signal, i.e. bone morphogenetic protein (BMP) signaling, to promote epidermal changes in psoriasis. Whereas BMP7 is strictly confined to the basal KC layer in the healthy skin, it is expressed at high levels throughout the lesional psoriatic epidermis. BMP7 instructs precursor cells to differentiate into LCs that phenotypically resemble psoriatic LCs. These BMP7-LCs exhibit proliferative activity and increased sensitivity to bacterial stimulation. Moreover, aberrant high BMP signaling in the lesional epidermis is mediated by a KC intrinsic mechanism, as suggested from murine data and clinical outcome after topical anti-psoriatic treatment in human patients. CONCLUSION Our data indicate that available TGF-β family members within the lesional psoriatic epidermis preferentially signal through the canonical BMP signaling cascade to instruct inflammatory-type LCs and to promote psoriatic epidermal changes. Targeting BMP signaling might allow to therapeutically interfere with cutaneous psoriatic manifestations

Central memory T cells are the most effective precursors of resident memory T cells in human skin

The circulating precursor cells that give rise to human resident memory T cells (TRM) are poorly characterized. We used an in vitro differentiation system and human skin-grafted mice to study TRM generation from circulating human memory T cell subsets. In vitro TRM differentiation was associated with functional changes, including enhanced IL-17A production and FOXP3 expression in CD4+ T cells and granzyme B production in CD8+ T cells, changes that mirrored the phenotype of T cells in healthy human skin. Effector memory T cells (TEM) had the highest conversion rate to TRM in vitro and in vivo, but central memory T cells (TCM) persisted longer in the circulation, entered the skin in larger numbers, and generated increased numbers of TRM. In summary, TCM are highly efficient precursors of human skin TRM, a feature that may underlie their known association with effective long-term immunity