[Histiocytic sarcoma in the Swiss population of Bernese mountain dogs: a retrospective study of its genetic predisposition]

A retrospective study to evaluate the genetic predisposition for histiocytic sarcoma in the Swiss population of purebred Bernese mountain dogs identified 51 histologically confirmed cases between 1997 and 2003. Segregation analysis using five major genetic modes was used to evaluate the 51 cases. The general mode yielded the best results suggesting a genetic predisposition for histiocystic sarcoma in this breed. The disease was found in all families analyzed, therefore elimination of the disease through seletive breeding of certain family lines is not possible.

Combined treatment with zidovudine and lymphoblast interferon-alpha in patients with HIV-related Kaposi's sarcoma

A combination of oral zidovudine (250 mg twice daily) and subcutaneous interferon-alpha (10 x 10(6) units daily) was evaluated for clinical, antiretroviral, and immunological efficacy and for side effects in 17 patients with AIDS-related Kaposi's sarcoma. Fifteen patients were evaluable. During the study period of 12 weeks, tumor responses were complete in two patients and partial in two patients (27% major response rate). Minimal responses were seen in two patients (40% overall response rate). An anti-HIV effect (reduction of serum p24 antigen by 70% or more) was observed in seven of ten evaluable patients who were initially antigenemic. CD4 lymphocyte counts remained unchanged. In six patients who had either a tumor response or a marked decline of HIV antigenemia, the treatment was continued between 12 and 59 weeks beyond the study period. Two of four patients with tumor regression at 12 weeks had an additional tumor response in this period despite prior dose reduction of interferon due to toxicity. Late progression of KS was eventually observed in four of six patients on prolonged treatment. The responsiveness of Kaposi's sarcoma seen in this study in patients with low CD4 counts and prior constitutional symptoms (fever, weight loss) was unexpected and needs further confirmation by larger patient groups. Dose-limiting toxicities were bone marrow depression (severe anemia in four and neutropenia with anemia in two patients), subjective adverse experiences (fever, fatigue, myalgia; four patients) and both (two patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Loss of pulp sensitivity and pain as the first symptoms of a Ewing's sarcoma in the right maxillary sinus and alveolar process: report of a case

This case report describes the diagnosis and treatment of a Ewing's sarcoma in the right maxillary sinus and alveolar bone of a 19-year-old female patient. The first clinical symptoms were a loss of sensitivity of the premolars and first molar in the right maxilla and acute pain located in the area of these teeth. Initially, the referring dentist had treated these findings as an acute apical periodontitis with root canal medication. Because swellings on the palatal and buccal aspects of the teeth occurred and could not be treated with incision and drainage, the dentist referred the patient. Cone-beam computed tomography revealed a proliferation of soft tissue in the right maxillary sinus, with a radiopaque material at the tip of the mesiobuccal root of the first molar and resorptive signs of the mesiobuccal and distobuccal roots of the first molar. The palatal cortical bone of the right alveolar process seemed to be intact. After explorative surgery with biopsies from the buccal, palatal, and sinus proliferation areas, the pathologist diagnosed the lesion as a Ewing's sarcoma. Treatment of the patient consisted of initial chemotherapy, hemimaxillectomy, and postsurgical chemoradiotherapy.

High expression of neuropeptide Y1 receptors in ewing sarcoma tumors

PURPOSE: Peptide receptors are frequently overexpressed in human tumors, allowing receptor-targeted scintigraphic imaging and therapy with radiolabeled peptide analogues. Neuropeptide Y (NPY) receptors are new candidates for these applications, based on their high expression in specific cancers. Because NPY receptors are expressed in selected sarcoma cell lines and because novel treatment options are needed for sarcomas, this study assessed the NPY receptor in primary human sarcomas. EXPERIMENTAL DESIGN: Tumor tissues of 88 cases, including Ewing sarcoma family of tumors (ESFT), synovial sarcomas, osteosarcomas, chondrosarcomas, liposarcomas, angiosarcomas, rhabdomyosarcomas, leiomyosarcomas, and desmoid tumors, were investigated for NPY receptor protein with in vitro receptor autoradiography using (125)I-labeled NPY receptor ligands and for NPY receptor mRNA expression with in situ hybridization. RESULTS: ESFT expressed the NPY receptor subtype Y1 on tumor cells in remarkably high incidence (84%) and density (mean, 5,314 dpm/mg tissue). Likewise, synovial sarcomas expressed Y1 on tumor cells in high density (mean, 7,497 dpm/mg; incidence, 40%). The remaining tumors expressed NPY receptor subtypes Y1 or Y2 at lower levels. Moreover, many of the sarcomas showed Y1 expression on intratumoral blood vessels. In situ hybridization for Y1 mRNA confirmed the autoradiography results. CONCLUSIONS: NPY receptors are novel molecular markers for human sarcomas. Y1 may inhibit growth of specific sarcomas, as previously shown in an in vivo mouse model of human ESFT. The high Y1 expression on tumor cells of ESFT and synovial sarcomas and on blood vessels in many other sarcomas represents an attractive basis for an in vivo tumor targeting.

Low-grade endometrial stromal sarcoma with inferior vena cava tumor thrombus and intracardiac extension: radical resection may improve recurrence free survival

BACKGROUND: Endometrial stromal sarcoma (ESS) represents 0.2% of all uterine malignancies. Based on the mitotic activity, a distinction is made between low and high-grade ESS. Although the overall five-year survival rate for low-grade ESS exceeds 80%, about 50% of the patients show tumor recurrence, mostly after a long latency period. Tumor invasion of the great vessels is extremely rare. We describe a patient with advanced low-grade ESS with tumor invasion of the infrarenal aorta and the inferior vena cava. The patient presented with a large tumor thrombus extending from the inferior vena cava into the right atrium. METHODS: Review of literature and identification of 19 patients, including our own case report, with advanced low-grade ESS with invasion of the great vessels and formation of an inferior vena cava tumor thrombus. RESULTS: All 19 patients presented with an abdominal tumor mass and a tumor thrombus protruding into the inferior vena cava. The tumor thrombus extended into the right heart cavities in nine patients reaching the right atrium in four, the right ventricle in three and the pulmonary artery in two patients. There were 5 patients with an advanced primary tumor and 14 patients with an advanced recurrent tumor. Seven patients presented with synchronous metastatic disease and six patients with a pelvic tumor infiltrating the bladder, the rectosigmoid colon or the infrarenal aorta. Mean age at surgery was 45.9+/-12.3 years (median 47, range 25-65 years). Tumor thrombectomy was accomplished by cavatomy or by right atriotomy after installation of a cardiopulmonary bypass. There was no peri-operative mortality and a very low morbidity. Radical tumor resections were achieved in 10 patients. The follow-up for these 10 patients was 2+/-1.3 years (median 2, range 0.3-4.5 years). Nine patients remained recurrence free whereas one patient suffered an asymptomatic local recurrence. CONCLUSIONS: Low-grade ESS is a rare angioinvasive tumor with a high recurrence rate. Resection of an inferior vena cava tumor thrombus, even with extension into the right heart cavities, can be performed safely. Extensive radical surgery is therefore justified in the treatment of advanced tumor manifestations of a low-grade ESS potentially improving recurrence free survival.

Predicting the evolution of Kaposi sarcoma, in the highly active antiretroviral therapy era

BACKGROUND: The outcome of Kaposi sarcoma varies. While many patients do well on highly active antiretroviral therapy, others have progressive disease and need chemotherapy. In order to predict which patients are at risk of unfavorable evolution, we established a prognostic score. METHOD: The survival analysis (Kaplan-Meier method; Cox proportional hazards models) of 144 patients with Kaposi sarcoma prospectively included in the Swiss HIV Cohort Study, from January 1996 to December 2004, was conducted. OUTCOME ANALYZED: use of chemotherapy or death. VARIABLES ANALYZED: demographics, tumor staging [T0 or T1 (16)], CD4 cell counts and HIV-1 RNA concentration, human herpesvirus 8 (HHV8) DNA in plasma and serological titers to latent and lytic antigens. RESULTS: Of 144 patients, 54 needed chemotherapy or died. In the univariate analysis, tumor stage T1, CD4 cell count below 200 cells/microl, positive HHV8 DNA and absence of antibodies against the HHV8 lytic antigen at the time of diagnosis were significantly associated with a bad outcome.Using multivariate analysis, the following variables were associated with an increased risk of unfavorable outcome: T1 [hazard ratio (HR) 5.22; 95% confidence interval (CI) 2.97-9.18], CD4 cell count below 200 cells/microl (HR 2.33; 95% CI 1.22-4.45) and positive HHV8 DNA (HR 2.14; 95% CI 1.79-2.85).We created a score with these variables ranging from 0 to 4: T1 stage counted for two points, CD4 cell count below 200 cells/microl for one point, and positive HHV8 viral load for one point. Each point increase was associated with a HR of 2.26 (95% CI 1.79-2.85). CONCLUSION: In the multivariate analysis, staging (T1), CD4 cell count (<200 cells/microl), positive HHV8 DNA in plasma, at the time of diagnosis, predict evolution towards death or the need of chemotherapy.

Treatment response and mortality among patients starting antiretroviral therapy with and without Kaposi sarcoma: a cohort study

BACKGROUND Improved survival among HIV-infected individuals on antiretroviral therapy (ART) has focused attention on AIDS-related cancers including Kaposi sarcoma (KS). However, the effect of KS on response to ART is not well-described in Southern Africa. We assessed the effect of KS on survival and immunologic and virologic treatment responses at 6- and 12-months after initiation of ART. METHODS We analyzed prospectively collected data from a cohort of HIV-infected adults initiating ART in South Africa. Differences in mortality between those with and without KS at ART initiation were estimated with Cox proportional hazard models. Log-binomial models were used to assess differences in CD4 count response and HIV virologic suppression within a year of initiating treatment. RESULTS Between January 2001-January 2008, 13,847 HIV-infected adults initiated ART at the study clinics. Those with KS at ART initiation (n = 247, 2%) were similar to those without KS (n = 13600,98%) with respect to age (35 vs. 35yrs), presenting CD4 count (74 vs. 85cells/mm³) and proportion on TB treatment (37% vs. 30%). In models adjusted for sex, baseline CD4 count, age, treatment site, tuberculosis and year of ART initiation, KS patients were over three times more likely to have died at any time after ART initiation (hazard ratio[HR]: 3.62; 95% CI: 2.71-4.84) than those without KS. The increased risk was highest within the first year on ART (HR: 4.05; 95% CI: 2.95-5.55) and attenuated thereafter (HR: 2.30; 95% CI: 1.08-4.89). Those with KS also gained, on average, 29 fewer CD4 cells (95% CI: 7-52cells/mm³) and were less likely to increase their CD4 count by 50 cells from baseline (RR: 1.43; 95% CI: 0.99-2.06) within the first 6-months of treatment. CONCLUSIONS HIV-infected adults presenting with KS have increased risk of mortality even after initiation of ART with the greatest risk in the first year. Among those who survive the first year on therapy, subjects with KS demonstrated a poorer immunologic response to ART than those without KS.

Kaposi sarcoma-associated herpes virus and response to antiretroviral therapy: a prospective study of HIV-infected adults

BACKGROUND The possible impact of coinfection with the Kaposi sarcoma-associated herpes virus (KSHV) on the response to antiretroviral therapy (ART) is unknown. Prospective studies are rare, particularly in Africa. METHODS We enrolled a prospective cohort of HIV-infected adults initiating ART in Johannesburg, South Africa. The subjects were defined as seropositive to KSHV if they were reactive to either KSHV lytic K8.1 or latent Orf73 antigen or to both. The subjects were followed from ART initiation until 18 months of treatment. HIV viral load and CD4 counts were tested 6 monthly. Linear generalized estimating and log-binomial regression models were used to estimate the effect of KSHV infection on immunologic recovery and response and HIV viral load suppression within 18 months after ART initiation. RESULTS Three hundred eighty-five subjects initiating ART from November 2008 to March 2009 were considered to be eligible including 184 (48%) KSHV+. The KSHV+ group was similar to the KSHV- in terms of age, gender, initiating CD4 count, body mass index, tuberculosis, and hemoglobin levels. The KSHV+ group gained a similar number of cells at 6 [difference of 10 cells per cubic millimeter, 95% confidence interval (CI): -11 to 31], 12 (3 cells per cubic millimeter, 95% CI: -19 to 25), and 18 months (24 cells per cubic millimeter, 95% CI: -13 to 61) compared with that gained by the KSHV- group. Adjusted relative risk of failure to suppress viral load to <400 copies per milliliter (1.03; 95% CI: 0.90 to 1.17) were similar for KSHV+ and KSHV- by 6 months on treatment. CONCLUSIONS In a population with a high KSHV prevalence, HIV-positive adults coinfected with KSHV achieved similar immunologic and virologic responses to ART early after treatment initiation compared with those with KSHV-.

Delta like ligand 4 is a critical regulator of bone marrow cell differentiation into pericytes/vascular smooth muscle cells and is essential for the vasculogenesis that supports the growth of Ewing’s sarcoma

We have previously shown that vasculogenesis, the process by which bone marrow-derived cells are recruited to the tumor and organized to form a blood vessel network de novo, is essential for the growth of Ewing’s sarcoma. We further demonstrated that these bone marrow cells differentiate into pericytes/vascular smooth muscle cells(vSMC) and contribute to the formation of the functional vascular network. The molecular mechanisms that control bone marrow cell differentiation into pericytes/vSMC in Ewing’s sarcoma are poorly understood. Here, we demonstrate that the Notch ligand Delta like ligand 4 (DLL4) plays a critical role in this process. DLL4 is essential for the formation of mature blood vessels during development and in several tumor models. Inhibition of DLL4 causes increased vascular sprouting, decreased pericyte coverage, and decreased vessel functionality. We demonstrate for the first time that DLL4 is expressed by bone marrow-derived pericytes/vascular smooth muscle cells in two Ewing’s sarcoma xenograft models and by perivascular cells in 12 out of 14 patient samples. Using dominant negative mastermind to inhibit Notch, we demonstrate that Notch signaling is essential for bone marrow cell participation in vasculogenesis. Further, inhibition of DLL4 using either shRNA or the monoclonal DLL4 neutralizing antibody YW152F led to dramatic changes in blood vessel morphology and function. Vessels in tumors where DLL4 was inhibited were smaller, lacked lumens, had significantly reduced numbers of bone marrow-derived pericyte/vascular smooth muscle cells, and were less functional. Importantly, growth of TC71 and A4573 tumors was significantly inhibited by treatment with YW152F. Additionally, we provide in vitro evidence that DLL4-Notch signaling is involved in bone marrow-derived pericyte/vascular smooth muscle cell formation outside of the Ewing’s sarcoma environment. Pericyte/vascular smooth muscle cell marker expression by whole bone marrow cells cultured with mouse embryonic stromal cells was reduced when DLL4 was inhibited by YW152F. For the first time, our findings demonstrate a role for DLL4 in bone marrow-derived pericyte/vascular smooth muscle differentiation as well as a critical role for DLL4 in Ewing’s sarcoma tumor growth.

Activation of Src kinase Lyn by the Kaposi sarcoma-associated herpesvirus K1 protein: implications for lymphomagenesis.

The K1 gene of Kaposi sarcoma-associated herpesvirus (KSHV) encodes a transmembrane glycoprotein bearing a functional immunoreceptor tyrosine-based activation motif (ITAM). Previously, we reported that the K1 protein induced plasmablastic lymphomas in K1 transgenic mice, and that these lymphomas showed enhanced Lyn kinase activity. Here, we report that systemic administration of the nuclear factor kappa B (NF-kappaB) inhibitor Bay 11-7085 or an anti-vascular endothelial growth factor (VEGF) antibody significantly reduced K1 lymphoma growth in nude mice. Furthermore, in KVL-1 cells, a cell line derived from a K1 lymphoma, inhibition of Lyn kinase activity by the Src kinase inhibitor PP2 decreased VEGF induction, NF-kappaB activity, and the cell proliferation index by 50% to 75%. In contrast, human B-cell lymphoma BJAB cells expressing K1, but not the ITAM sequence-deleted mutant K1, showed a marked increase in Lyn kinase activity with concomitant VEGF induction and NF-kappaB activation, indicating that ITAM sequences were required for the Lyn kinase-mediated activation of these factors. Our results suggested that K1-mediated constitutive Lyn kinase activation in K1 lymphoma cells is crucial for the production of VEGF and NF-kappaB activation, both strongly implicated in the development of KSHV-induced lymphoproliferative disorders.

Cryo-electron tomography of Kaposi's sarcoma-associated herpesvirus capsids reveals dynamic scaffolding structures essential to capsid assembly and maturation.

Kaposi's sarcoma-associated herpesvirus (KSHV) is a recently discovered DNA tumor virus that belongs to the gamma-herpesvirus subfamily. Though numerous studies on KSHV and other herpesviruses, in general, have revealed much about their multilayered organization and capsid structure, the herpesvirus capsid assembly and maturation pathway remains poorly understood. Structural variability or irregularity of the capsid internal scaffolding core and the lack of adequate tools to study such structures have presented major hurdles to earlier investigations employing more traditional cryo-electron microscopy (cryoEM) single particle reconstruction. In this study, we used cryo-electron tomography (cryoET) to obtain 3D reconstructions of individual KSHV capsids, allowing direct visualization of the capsid internal structures and systematic comparison of the scaffolding cores for the first time. We show that B-capsids are not a structurally homogenous group; rather, they represent an ensemble of "B-capsid-like" particles whose inner scaffolding is highly variable, possibly representing different intermediates existing during the KSHV capsid assembly and maturation. This information, taken together with previous observations, has allowed us to propose a detailed pathway of herpesvirus capsid assembly and maturation.

Direct visualization of the putative portal in the Kaposi's sarcoma-associated herpesvirus capsid by cryoelectron tomography.

Genetic and biochemical studies have suggested the existence of a bacteriophage-like, DNA-packaging/ejecting portal complex in herpesviruses capsids, but its arrangement remained unknown. Here, we report the first visualization of a unique vertex in the Kaposi's sarcoma-associated herpesvirus (KSHV) capsid by cryoelectron tomography, thus providing direct structural evidence for the existence of a portal complex in a gammaherpesvirus. This putative KSHV portal is an internally localized, umbilicated structure and lacks all of the external machineries characteristic of portals in DNA bacteriophages.

Analysis of the Soehner-Dmochowski strain of Moloney murine sarcoma virus

The Soehner-Dmochowski strain of murine sarcoma virus (MuSV-SD) was derived from a bone tumor of a New Zealand Black (NZB) rat infected with the Moloney strain of MuSV, which carries the gene encoding the v-mos protein. Serial passage of cell-free tumor extracts both decreased the latent period and resulted in osteosarcomas. Cells from a late passage tumor were established in culture, cell-free extracts frozen, and later inoculated into newborn NZB rats. One of the resulting bone tumors was established in culture and clonal cell lines derived, of which S4 was selected for the present study. The objectives of the study were two-fold: an examination of the genetic organization of MuSV-SD, and an examination of the biochemical characteristics of the viral proteins, since this is an acutely transforming virus which may yield insights into the mechanism of transformation caused by the v-mos protein. Blot hybridization of digested S4 genomic DNA reveals three candidate MuSV-SD integrated viral DNAs. The largest of these, MuSV-SD-6.5, was cloned from an S4 cosmid library, and the complete MuSV-SD-mos sequence was determined. The predicted amino acid sequence of the v-mos protein was compared to that of MuSV-124 and Ht-1, which show a 96.5% and 97.1% similarity, respectively. To characterize the MuSV-SD-mos protein further, immunochemical assays were performed using anti-mos antisera. The immunoblot analysis and immunoprecipitation assays demonstrated that similar levels of the v-mos protein were present in cells chronically infected with either MuSV-SD or MuSV-124; however, the immune complex kinase assay revealed greatly reduced in vitro serine kinase activity of the MuSV-SD-mos protein compared to that of MuSV-124. Sequence analysis demonstrated that the serine at amino acid residue 358 of the MuSV-SD-mos protein, like that of MuSV-Ht-1, had been mutated to a glycine. Mutations of this serine residue have been shown to affect the detectable in vitro kinase activity, however, v-mos proteins containing this mutation still retain transforming properties. Therefore, although the characteristic in vitro kinase activity of the MuSV-SD-mos protein has not been demonstrated, it is clear that this virus is a potent transforming agent. ^

MONOCLONAL ANTIBODY CHARACTERIZATION OF RAT TRANSFORMATION ASSOCIATED PROTEINS INDUCED BY MOLONEY MURINE SARCOMA VIRUS

By the use of Moloney murine sarcoma virus (Mo-MSV)-induced rat bone tumor (RBT) cells as immunogens, and the hybridoma technique, a mouse hybridoma clone was isolated in Dr. Chan's lab (Chan et al., 1983), which produced a monoclonal antibody, designated MC. MC detected specific antigens in three different Mo-MSV-transformed rat cell lines: 78A1 WRC, RBT and 6M2 (NRK cells infected with the ts110 mutant of Mo-MSV), but not in their untransformed counterparts. These antigens are tentatively termed transformation associated proteins (TAP). In this study, TAP were hypothesized to be the rat specific proteins which are activated by Mo-MSV and play an important role in cellular transformation, and were further investigated. Their properties are summarized as follows: (1) TAP may represent cellular products localized in the cytoplasm of 6M2 cells. (2) The expression of TAP is temperature-sensitive and related to cellular transformation, and probably activated by the v-mos gene products. The optimal temperature for the expression of both P85('gag-mos), the only known viral transforming protein in 6M2 cells, and TAP was 28(DEGREES)C. The expression of both P85('gag-mos) and TAP was proportional to the degree of transformation of 6M2 cells. (3) There were four antigenically-related forms of intracellular TAP (P66, P63, P60 and P58) in 6M2 cells. After synthesis, the 58Kd TAP was probably converted to one of the other three forms. These three polypeptides (P66, P63 and P60) were rapidly converted to two (P68 and P64) and subsequently secreted to the extracellular medium with a 50% secretion rate of 78 min. The conversion of these molecular sizes of TAP is probably related to glycosylation. Inhibition of TAP glycosylation by 0.5 ug/ml of tunicamycin could retard the secretion rate of TAP by 39%. (4) TAP are phosphoproteins, but not associated with any protein kinase activity. (5) TAP have been purified, and found to be mitogenic NRK-2 cells. TAP can bind to the receptors of NRK-2 cells with a K(,d) of 1.4 pM and with about 2 x 10('5) binding sites for TAP per NRK-2 cell. (6) Some weak proteolytic activity was found to associate with purified TAP. ^