Evidence of Inbreeding in Hodgkin Lymphoma.

Genome-wide association studies (GWASs) have identified several, mainly co-dominantly acting, single-nucleotide polymorphisms (SNPs) associated with Hodgkin lymphoma (HL). We searched for recessively acting disease loci by performing an analysis of runs of homozygosity (ROH) based on windows of homozygous SNP-blocks and by calculating genomic inbreeding coefficients on a SNP-wise basis. We used data from a previous GWAS with 906 cases and 1217 controls from a population with a long history of no matings between relatives. Ten recurrent ROHs were identified among 25 055 ROHs across all individuals but their association with HL was not genome-wide significant. All recurrent ROHs showed significant evidence for natural selection. As a novel finding genomic inbreeding among cases was significantly higher than among controls (P = 2.11*10-14) even after correcting for covariates. Higher inbreeding among the cases was mainly based on a group of individuals with a higher average length of ROHs per person. This result suggests a correlation of higher levels of inbreeding with higher cancer incidence and might reflect the existence of recessive alleles causing HL. Genomic inbreeding may result in a higher expression of deleterious recessive genes within a population.

Heritability estimates on Hodgkin's lymphoma: a genomic- versus population-based approach.

Genome-wide association studies (GWASs) have identified several single-nucleotide polymorphisms (SNPs) influencing the risk of Hodgkin's lymphoma (HL) and demonstrated the association of common genetic variation for this type of cancer. Such evidence for inherited genetic risk is also provided by the family history and the very high concordance between monozygotic twins. However, little is known about the genetic and environmental contributions. A common measure for describing the phenotypic variation due to genetics is the heritability. Using GWAS data on 906 HL cases by considering all typed SNPs simultaneously, we have calculated that the common variance explained by SNPs accounts for >35% of the total variation on the liability scale in HL (95% confidence interval 6-62%). These findings are consistent with similar heritability estimates of ∼ 0.40 (95% confidence interval 0.17-0.58) based on Swedish population data. Our estimates support the underlying polygenic basis for susceptibility to HL, and show that heritability based on the population data is somehow larger than heritability based on the genomic data because of the possibility of some missing heritability in the GWAS data. Besides that there is still major evidence for multiple loci causing HL on chromosomes other than chromosome 6 that need to be detected. Because of limited findings in prior GWASs, it seems worth checking for more loci causing susceptibility to HL.

Bruton's tyrosine kinase: from X-linked agammaglobulinemia toward targeted therapy for B-cell malignancies.

Discovery of Bruton's tyrosine kinase (BTK) mutations as the cause for X-linked agammaglobulinemia was a milestone in understanding the genetic basis of primary immunodeficiencies. Since then, studies have highlighted the critical role of this enzyme in B-cell development and function, and particularly in B-cell receptor signaling. Because its deletion affects mostly B cells, BTK has become an attractive therapeutic target in autoimmune disorders and B-cell malignancies. Ibrutinib (PCI-32765) is the most advanced BTK inhibitor in clinical testing, with ongoing phase III clinical trials in patients with chronic lymphocytic leukemia and mantle-cell lymphoma. In this article, we discuss key discoveries related to BTK and clinically relevant aspects of BTK inhibitors, and we provide an outlook into clinical development and open questions regarding BTK inhibitor therapy.

Variation at 3p24.1 and 6q23.3 influences the risk of Hodgkin's lymphoma.

In addition to HLA, recent genome-wide association studies (GWASs) of Hodgkin's lymphoma (HL) have identified susceptibility loci for HL at 2p16.1, 8q24.21 and 10p14. In this study, we perform a GWAS meta-analysis with published GWAS (totalling 1,465 cases and 6,417 controls of European background), and follow-up the most significant association signals in 2,024 cases and 1,853 controls. A combined analysis identifies new HL susceptibility loci mapping to 3p24.1 (rs3806624; P=1.14 × 10(-12), odds ratio (OR)=1.26) and 6q23.3 (rs7745098; P=3.42 × 10(-9), OR=1.21). rs3806624 localizes 5' to the EOMES (eomesodermin) gene within a p53 response element affecting p53 binding. rs7745098 maps intergenic to HBS1L and MYB, a region previously associated with haematopoiesis. These findings provide further insight into the genetic and biological basis of inherited susceptibility to HL.

Galectin-1 serum levels reflect tumor burden and adverse clinical features in classical Hodgkin lymphoma.

Galectin-1 (Gal1) is a member of a highly conserved family of carbohydrate-binding proteins. It modulates innate and adaptive immune responses and fosters tumor-immune escape. Hodgkin lymphoma (HL) Reed-Sternberg cells overexpress and secrete Gal1, which selectively kills T helper (Th)1 and Th17 cells and cytotoxic T cells and promotes the immunosuppressive Th2/regulatory T-cell-predominant HL microenvironment. We developed a sandwich enzyme-linked immunosorbent assay and assessed serum Gal1 levels in 293 newly diagnosed, previously untreated patients with classical HL (cHL) enrolled in 3 risk-adapted clinical trials. Serum Gal1 levels were significantly higher in patients with cHL than in normal controls (P < .0001). Gal1 serum levels also increased with Ann Arbor stage (P = .012), areas of nodal involvement (P < .0001), and the International Prognostic Score (2-7, P = .019). We conclude that Gal1 serum levels are significantly associated with tumor burden and related clinical features in newly diagnosed cHL patients.

Baseline serum TARC levels predict therapy outcome in patients with Hodgkin lymphoma.

Hodgkin lymphoma (HL) has become one of the best curable cancers. However, better biomarkers are needed for outcome prediction that would allow protecting patients from over- or under-dosing of treatment. Thymus and activation-regulated chemokine/CCL17 (TARC) is highly and specifically elevated in this disease and has been proposed as possible biomarker in HL patients. In this study, we show that pretreatment TARC levels were associated with established clinical risk factors and predictive for response to treatment in a large cohort of HL patients treated in clinical trials by the German Hodgkin Study Group. Moreover, TARC levels also significantly contributed to a novel multivariate model predicting treatment response. These data clearly suggest an important role for this chemokine as biomarker in HL.

The Bruton tyrosine kinase inhibitor PCI-32765 thwarts chronic lymphocytic leukemia cell survival and tissue homing in vitro and in vivo.

B-cell receptor (BCR) signaling is a critical pathway in the pathogenesis of several B-cell malignancies, including chronic lymphocytic leukemia (CLL), and can be targeted by inhibitors of BCR-associated kinases, such as Bruton tyrosine kinase (Btk). PCI-32765, a selective, irreversible Btk inhibitor, is a novel, molecularly targeted agent for patients with B-cell malignancies, and is particularly active in patients with CLL. In this study, we analyzed the mechanism of action of PCI-32765 in CLL, using in vitro and in vivo models, and performed correlative studies on specimens from patients receiving therapy with PCI-32765. PCI-32765 significantly inhibited CLL cell survival, DNA synthesis, and migration in response to tissue homing chemokines (CXCL12, CXCL13). PCI-32765 also down-regulated secretion of BCR-dependent chemokines (CCL3, CCL4) by the CLL cells, both in vitro and in vivo. In an adoptive transfer TCL1 mouse model of CLL, PCI-32765 affected disease progression. In this model, PCI-32765 caused a transient early lymphocytosis, and profoundly inhibited CLL progression, as assessed by weight, development, and extent of hepatospenomegaly, and survival. Our data demonstrate that PCI-32765 effectively inhibits CLL cell migration and survival, possibly explaining some of the characteristic clinical activity of this new targeted agent.

In vivo performance of selective electron beam-melted Ti-6Al-4V structures.

Highly porous titanium structures are widely used for maxillofacial and orthopedic surgery because of their excellent mechanical properties similar to those of human bone and their facilitation of bone ingrowth. In contrast to common methods, the generation of porous titaniumproducts by selective electron beam melting (SEBM), an additive manufacturing technology, overcomes difficulties concerning the extreme chemical affinity of liquid titanium to atmospheric gases which consequently leads to strongly reduced ductility of the metal. The purpose of this study was to assess the suitability of a smooth compact and a porous Ti-6Al-4V structure directly produced by the SEBM process as scaffolds for bone formation. SEBM-processed titanium implants were placed into defects in the frontal skull of 15 domestic pigs. To evaluate the direct contact between bone and implant surfaces and to assess the ingrowth of osseous tissue into the porous structure, microradiographs and histomorphometric analyses were performed 14, 30, and 60 days after surgery. Bone ingrowth increased significantly during the period of this study. After 14 days the most outer regions of the implants were already filled with newly formed bone tissue (around 14%). After 30 days the bone volume inside the implants reached almost 30% and after 60 days abundant bone formation inside the implants attained 46%. During the study only scarce bone-implant contact was found around all implants, which did not exceed 9% around compact specimens and 6% around porous specimens after 60 days. This work demonstrates that highly porous titanium implants with excellent interconnectivity manufactured using the SEBM method are suitable scaffolds for bone ingrowth. This technique is a good candidate for orthopedic and maxillofacial applications.

A novel multiple-marker method for the early diagnosis of oral squamous cell carcinoma.

OBJECTIVE: Melanoma associated antigens-A (MAGE-A) expression is highly specific to cancer cells. Thus, they can be the most suitable targets for the diagnosis of malignancy. The aim of this study was to evaluate the sensitivity of multiple MAGE-A expression analysis for the diagnosis of oral squamous cell carcinoma (OSCC). METHODS: Total of 70 OSSC and 20 normal oral mucosal (NOM) samples of otherwise healthy volunteers were examined for the expression of 10 different single antigens out of 12 different MAGE-A subtypes by highly sensitive reverse transcriptase polymerase chain reaction (RT-PCR) methods. The results were correlated to clinicopathological parameters of tumor samples. RESULTS: Expression of MAGE-A was restricted to OSCC. The expression frequency of single antigen was between 10% and 55%. However, expression rate was increased up to 93% by the elevated number of genes examined. A significant correlation was found between the expression of MAGE-A and malignancy (p = 0.0001). In addition, multiple MAGE-A detection has also correlated to the incidence of lymph node metastasis, grading and advanced clinical stages. CONCLUSIONS: Analysis of multiple MAGE-A expression is more sensitive than the analysis of a single MAGE-A for the diagnostic evaluation of OSCC. Multiple MAGE-A expression analysis may be a very sensitive method to be used for the diagnosis even in the early stage of OSCC.

In vitro behavior of layer-by-layer deposited molecular oligoelectrolyte films on Ti-6Al-4V surfaces.

Layer-by-layer self-assembled films of molecular oligoelectrolytes were used to modify Ti-6Al-4V surfaces in order to test their ability as potential drug delivery system. With regard to medical application the in vitro behavior of the modified material was investigated. The Ti-6Al-4V (6% aluminium, 4% vanadium) material was treated in a layer-by-layer (LbL) process with 2, 4, 6 and 8 layers of molecular oligoelectrolytes 1 and 2 and thereby doped with a fluorescent reporter molecule 2. Human osteoblasts were cultured for a period up to 5 days on the modified material. Ti-6Al-4V surfaces without modification were used as control. In order to investigate the in vitro behavior of the coating as well as the influence of components of the coating on osteoblastic cells, respectively, cell proliferation, differentiation and attachment of hFOB cells were observed by means of cell number, osteoblastic gene expression and fluorescence microscopy. Degradation behavior of the OEM (oligoelectrolyte multilayer film) was examined using optical spectroscopy. Measurement data imply that the layer-by-layer coating was successfully assembled on the Ti surface and endures steam sterilization. The fluorescence signal in cell culture medium increased strictly linear with increasing pre-assembled number of layers on the surface. Proliferation rates of the cells in experimental groups did not differ significantly from each other (P >or= 0.783). Differentiation pattern was not significantly changed by the coating. The fluorescent reporter component of the film was absorbed by osteoblastic cells and was detected by fluorescence microscopy.

Early findings of a novel established molecular diagnostic technique for the prediction of malignant transformation in leukoplakia.

To date, there are no objective parameters regarding the early prediction of malignant transformation in leukoplakia. Expression analysis of melanoma-associated antigens (MAGE-A) can differentiate between healthy and already malignant transformed tissues. Thus, expression analysis may also be used as an additional diagnostic tool for oral pre-malignant lesions to monitor potential malignant changes. In this study, four specimens collected from the same patient within a year were examined. Specimens were taken from the part of the lesion that displayed a rapid progression from fibroma to oral squamous cell carcinoma (OSCC). Clinically and histopathologically, the oral lesion was first diagnosed as fibroma with inflammatory infiltration, then as leukoplakia with hyperplasia, then as leukoplakia with severe dysplasia, and lastly as OSCC. Expression of MAGE-A1, -A3, -A4, -A6, -A10 and -A12 was investigated in the frozen tissue specimens using RT-PCR and quantitative real-time RT-PCR. There was no expression of MAGE-A in the specimen of fibroma with inflammatory infiltration. However, four genes were expressed by the second specimen of leukoplakia with hyperplasia. With the exception of MAGE-A1, all antigens were expressed in the specimens, which were histopathologically diagnosed as leukoplakia with severe dysplasia and OSCC. Expression analysis of six different MAGE-A genes indicated a high potential for malignant change in the specimens diagnosed as leukoplakia that eventually developed into OSCC. Thus, analysis of MAGE-A expression can predict malignant transformation in leukoplakia.

In vitro response of hFOB cells to pamidronate modified sodium silicate coated cellulose scaffolds.

The aim of the present study was to evaluate the suitability of cellulose-based scaffolds coated with pure sodium silicate gel and sodium silicate gels accumulated with different concentrations of the bisphosphonate pamidronate as scaffolds for attachment, proliferation and differentiation of human fetal osteoblasts (hFOB 1.19). Human osteoblasts were cultured in vitro for a period up to 14 days on different cellulose scaffolds. Unmodified and sodium silicate coated cellulose scaffolds were used as control. Two surface-coated modifications of cellulose were applied. The scaffolds were coated in a modified two-step dip coating process with pure sodium silicate gel and pamidronate enriched sodium silicate gel, respectively. In order to investigate the influence of the pamidronate, concentrations of 0.667 mg Na-pamidronate/ml sodium silicate solution, 0.333 mg Na-pamidronate/ml sodium silicate solution and 3.33 x 10(-3) mg Na-pamidronate/ml sodium silicate solution were used for the coating process. Cell proliferation, vitality and attachment were examined by means of cell counting, WST-1 test, fluorescence and scanning electron microscopy. The relative grade of differentiation of hFOB cells was examined by using quantitative real-time polymerase chain reaction (qRT-PCR) analysis for the gene expression of alkaline phosphatase and osteocalcin. Proliferation and differentiation of human osteoblasts was enhanced by the sodium silicate coatings accumulated with pamidronate compared to pure sodium silicate coatings. There was a reciprocal correlation of vitality with the concentration of pamidronate. The highest vitality was found on surfaces with the lowest pamidronate accumulation. Alkaline phosphatase, an early differentiation marker, was overexpressed after 7 days in cells on all pamidronate-containing surfaces (up to 350% compared to untreated cellulose). Osteocalcin, a late differentiation marker, was overexpressed after 14 days in cells on all coated surfaces (up to 300,000% compared to untreated cellulose). The results indicate that due to the modified coating procedure a homogeneous coating and thus, an enhancement of cell attachment and subsequent cellular functions can be achieved. Low concentrations of pamidronate seem to have a relevant effect on cell proliferation and vitality and, therefore, can be recommended for the improvement of the properties of a biomaterial.

Effects of topographical surface modifications of electron beam melted Ti-6Al-4V titanium on human fetal osteoblasts.

The aim of the study was to assess the suitability of different Ti-6Al-4V surfaces produced by the electron beam melting (EBM) process as matrices for attachment, proliferation, and differentiation of human fetal osteoblasts (hFOB 1.19). Human osteoblasts were cultured in vitro on smooth and rough-textured Ti-6Al-4V alloy disks. By means of cell number and vitality and SEM micrographs cell attachment and proliferation were observed. The differentiation rate was examined by using quantitative real-time PCR analysis for the gene expression of alkaline phosphatase (ALP), type I collagen (Coll-I), bone sialoprotein (BSP) and osteocalcin (OC). After 3 days of incubation there was a significant higher vitality (p < 0.02) and proliferation (p < 0.02) of hFOB cells on smooth surfaces (R(a) = 0.077 microm) and compact surfaces with adherent partly molten titanium particles on the surface (R(a) /= 56.9 microm) reduced proliferation of hFOB cells. Surface characteristics of titanium can easily be changed by EBM in order to further improve proliferation.