bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is the Risk of Breast Cancer Increased after Hematopoietic Cell Transplantation?.
Authors: Friedman Debra L. , Leisenring Wendy , Schwartz Jeffrey , Deeg H. Joachim 
Published: October 2019

Abstract
Survivors of hematopoietic stem cell transplantation (HSCT) are at risk for second malignant neoplasms (SMN). As secondary breast cancer is now reported in excess among survivors of a variety of cancers treated with conventional chemoradiotherapy, we sought to explore the risk among HSCT survivors. Among 4,805 allogeneic transplant recipients treated at the Fred Hutchinson Cancer Research Center between November, 1969 and April, 2003, who survived at least 100 days post transplant, there were 27 females and 1 male with secondary breast cancer, representing the largest single diagnostic group of secondary solid tumors post transplant, following cancers of the skin and mucosa. Confining the analysis to the 2,042 female HSCT recipients, the cumulative incidence of secondary breast cancer at 25 years was 5.4% (95% Confidence Interval [CI]: 3.0%, 8.9%). The risk was twice that of the general population, using US SEER data for expected values (Age and race adjusted standardized incidence ratio = 2.3; 95% CI = 1.5, 3.3). The time to second breast cancer from transplant was 1-24.8 (median 9.3) years. In Cox regression, using time from transplant as the time scale, risk increased with increasing age at time of transplant, with hazard ratios [HR] of 12.6 (95% CI 1.6,97.9) for patients 18–39 years and 54.7 (95% CI 6.6,450.8) for those ≥ 40 years. However, when age was used as the time scale, this age effect was no longer seen (HR: 0.56; 95% CI: 0.06,5,3). We also investigated the role of preparatory regimen and graft versus host disease (GVHD) and found no associations with increased breast cancer risk. Specifically, use of TBI in the conditioning regimen (HR: 1.9; 95% CI: 0.8,4.7), type of alkylating agent used in the conditioning regimen (Busulfan HR: 2.0; 95% CI: 0.1,32.0; Cytoxan HR: 1.3 95%; CI: 0.2,10.5; Busulfan plus Cytoxan HR: 0.8; 95% CI: 0.1,6.7), donor type (related versus unrelated; HR: 1.3; 95% CI 0.5,3.2), nor acute (HR: 1.2; 95% CI: 0.5,2.6) or chronic GVHD (HR: 1.5; 95% CI: 0.7,3.3) increased risk for secondary breast cancer. The only treatment-related risk factor identified was the use of single fraction (versus fractionated) TBI, where the hazard ratio was 4.8 (95% CI: 1.5,16.2). Among 1,015 100+ day survivors of autologous transplants, excluding those transplanted for primary breast cancer, there were 2 female and 1 male breast cancer reported. These data suggest that, in contrast to the risk reported following conventional chemoradiotherapy, transplant preparatory regimens do not significantly increase risk for secondary breast cancer. In addition, GVHD, which is a risk factor for a number of SMNs following HSCT, does not appear to increase the risk for secondary breast cancer. Risk factors other than therapy should therefore be investigated to better understand the increased risk of breast cancer following HSCT and to develop appropriate preventive strategies.
HCV and HIV Envelope Proteins Co-Operatively Induce Fas-Mediated Apoptosis Via a Novel Stat1 Signaling Pathway.
Authors: Balasubramanian Anuradha , Ganju Ramesh K. , Groopman Jerome E. 
Published: October 2019

Abstract
Hepatitis C virus (HCV) co-infects approximately 40% of patients with human immunodeficiency virus (HIV). HCV/HIV co-infected patients often have progressive liver disease that can lead to cirrhosis and death. We observed that hepatocytes exposed to HCV and HIV envelope proteins undergo apoptosis via an ‘innocent bystander’ mechanism due to cell surface binding of viral proteins independent of direct viral infection. HCV envelope protein E2 (1.5 nM) and HIV envelope protein gp120 (0.8 nM) derived from M-tropic and T-tropic viruses induce significant apoptosis in both hepatocytic cell lines and primary hepatocytes, while either of these viral proteins alone does not. Now, we have elucidated the signaling mechanisms that mediate this effect. HCV-E2 and HIV-gp120 were found to significantly upregulate Fas ligand (FasL). We then examined the Stat family of proteins known to participate in FasL and apoptotic pathways. We observed an increased DNA binding activity of Stat1 upon HCV-E2 and HIV-gp120 stimulation. Furthermore, overexpression of wild type Stat1αincreased apoptosis and FasL expression in HepG2 cells, whereas a C-terminal domain deleted mutant, Stat1β, decreased HCV-E2 and HIV-gp120 mediated apoptosis and FasL upregulation. Overexpression of Stat1αand Stat1β in primary hepatocytes confirmed that Stat1αenhanced apoptosis upon HCV-E2 and HIV-gp120 treatment. We observed a tyrosine dependent activation of Stat1 and a subsequent serine phosphorylation of Stat1. TYK2, lyn kinase, RAFTK and MAP kinases were activated upstream of Stat1. In addition, Stat1 associated with the death domain-containing adapter protein TRADD. TRADD is known to induce inflammatory signaling through the NFκB pathway. Here, the association of Stat1 with TRADD would reduce the availability of TRADD to induce NFκB. Thus, Stat1 sequestration of downstream apoptotic signaling molecules would block the host inflammatory response. Further characterization of Fas-mediated apoptosis revealed that caspase 3 and caspase 7 were activated following HCV-E2 and HIV-gp120 stimulation. However, we were not able to detect significant activity of either caspase 8 or caspase 9. We also found a loss in mitochondrial membrane potential upon HCV-E2 and HIV-gp120 stimulation, which leads to the release of cytochrome C and AIF into the cytosol. Taken together, these studies indicate that the viral proteins of HCV and HIV co-operate in causing the apoptosis of hepatocytes, independent of direct infection, by induction of novel Stat1 downstream signaling pathways at the expense of a normal host inflammatory response.
Human Herpesvirus-8 (HHV-8/KSHV) Induces Reactive Oxygen Species in Endothelial Cells That Facilitate Virus Infection.
Authors: Wang Jian Feng , Zhang Xuefeng , Chandran Bala , Groopman Jerome E. 
Published: October 2019

Abstract
Reactive oxygen species (ROS) can activate replication of certain viruses, induce the production of various inflammatory mediators and play a critical role in carcinogenesis and tumor development. Kaposi’s sarcoma (KS) is the most prevalent HIV-associated cancer and is caused by infection with human herpesvirus-8 (HHV-8/KSHV). KS tissue has been reported to possess increased levels of ROS. We studied if ROS generation is related to HHV-8 infection and its role in virus entry into endothelial cells. Incubation of dermal microvascular endothelial cells (DMECs) with highly purified HHV-8 induced rapid increases in the production of intracellular hydrogen peroxide (H2O2), one of the major forms of ROS. Intracellular H2O2 was also induced by the treatment of DMECs with the HHV-8 envelope glycoprotein B (gB). The gB protein possesses an RGD motif, binds to the integrin molecules, alpha3 and beta1, and is a major mediator of virus entry into target cells. To test if it was integrin ligation that induces the production of ROS, we treated DMECs with fibronectin or laminin, the respective natural ligands for alpha3 and beta1 integrins. We observed a similar induction of intracellular ROS in DMECs by either matrix protein. These results indicated that the HHV-8-induced production of ROS was, at least in part, mediated by stimulation of integrins through the RGD-containing viral gB protein. ROS have recently been shown to function as second messengers in cellular signaling. To assess at which steps of cell signaling ROS may be functioning, we studied the signaling cascade in DMECs activated by the HHV-8 gB protein. Previous studies have shown that HHV-8, through gB/integrin interaction, induces cytoskeletal rearrangement and activates focal adhesion kinase (FAK), Src kinase and Akt, which are critical for virus entry into the target cells. We found that the activation of FAK, c-Src or Akt by this viral protein was inhibited by pretreatment with N-acetyl-L-cysteine (NAC), a potent thiol antioxidant. These results suggested that generation of ROS was involved in HHV-8-triggered signaling. We next examined if a change in ROS production modulated HHV-8 virus entry. We used green fluorescent protein (GFP)-labeled HHV-8 at a multiplicity of infection of 5–6, and quantitated the infection by fluorescence analysis of the DMECs. Short term exposure to low concentrations of H2O2 enhanced HHV-8 infection in DMECs, while treatment with NAC significantly decreased infection. These data indicated that ROS generation participated in HHV-8-mediated signaling and entry into target cells. Our study demonstrates a novel role of ROS in virus pathogenesis and provides a framework for the development of novel antioxidant strategies in AIDS-KS treatment.
Phase II Trial of Bortezomib in Mantle Cell Lymphoma.
Authors: Belch Andrew , Kouroukis C. Tom , Crump Michael , Sehn Laurie , Gascoyne Randy , Klasa Richard , Jean Powers , Eisenhauer Elizabeth 
Published: October 2019

Abstract
We report the results of a phase II trial of an investigational new drug bortezomib (PS-341, Velcade) for the treatment of mantle cell lymphoma. Advanced stage previously untreated patients or those given up to two prior chemotherapy regimens were eligible. Additional entry criteria included measurable nodal disease, minimum laboratory requirements, and written informed consent. Central pathology review, to confirm eligibility and the presence of cyclin D1, was required after study entry. Accrual was closed July 2004 having reached the preplanned target of 30 patients. Bortezomib 1.3 mg/m2 IV bolus was given days 1, 4, 8 and 11 in 3-week cycles. Patients were assessed by CT scanning after every two cycles of therapy and response assessed according to International Working Group recommendations (Cheson B, J Clin Oncol 1999). Non progressors were to receive a maximum of 4 cycles. Responding patients were to receive bortezomib for 2 cycles following documentation of maximal partial response (PR) or complete response (CR). To date demographic data are available on 26 patients. The median age was 67 (48–78 yrs), all had stage 3 or 4 disease (55% bone marrow involvement), 7 were female and 10 had received no prior chemotherapy. A median of 4 treatment cycles has been given (range 1–7) and 25 patients are evaluable for toxicity. Grade ≥ 2 adverse effects thought to be related to study drug occurred as follows: anorexia 8%, nausea 16%, vomiting 4%, diarrhea 20%, fatigue 60%, dizziness 4%, sensory neuropathy 12%, edema 8%, hypotension 4%, vascular leak syndrome 4%, arthralgia 12%, myalgia 12%, neuropathic pain 12%, dyspnea 12%, rash 12%. Nine patients discontinued therapy because of toxic effects (6 of whom had neuropathy or myalgia). During accrual of the first 14 patients, 5 serious adverse events occurred in patients with pre-existing edema, dyspnea, and/or effusion. Therefore, the eligibility criteria were amended to exclude such patients thereafter and no further serious adverse events have occurred. To date, 24 patients are evaluable for response. Of the 10 patients having no prior chemotherapy there were 3 PR (range 2.5–14.8m) 6 SD (1.3–13.6m) and 1 PD for a response of 30%. Of the 14 previously treated patients we obtained 1 CRu (14.1m), 4 PR (2.4–13.1m), 7 SD (1.2–14.3m) and 2 PD. The overall response rate is 33% (95% C.I. 16–55%) but interestingly it is similar in both previously untreated and treated groups. We conclude that bortezomib is an active agent in mantle cell lymphoma, but at this dose and schedule complete remission is rare. Since higher doses will not be possible given the frequency of neuropathy and myalgia, alternative schedules or novel combinations with other active agents will be of interest to pursue.
The Gas6 Receptor Axl Enhances Platelet Activation Responses through Stimulation of PI3kinase- and PLC-Dependent Signaling Pathways.
Authors: Gould Weston R. , Baxi Sangita , Perrin Lisa A. , Leadley Robert J. 
Published: October 2019

Abstract
At the site of vascular injury, platelet activation is paramount in supporting formation of a platelet plug and generating a functional surface for the protein elements of coagulation. Recently, we demonstrated that the receptors for the α-granule constituent Gas6, support and enhance platelet aggregation and dense-granule release. The current study examined additional affects of Gas6 signaling in human platelets and sought to decipher intracellular signaling mechanisms initiated by stimulation of Axl, a Gas6 platelet receptor. Flow cytometry analyses indicated that all three Gas6 receptors, Axl, Sky, and Mer were present on the platelet surface. Blockade of Gas6, Sky, or Mer by specific antibodies not only inhibited TRAP- and ADP-induced platelet aggregation and dense granule release, but also prevented thrombin mediated clot retraction by as much as 55%. Furthermore, intracellular calcium mobilization in response to TRAP activation was greater than 80% inhibited in the presence of each of these blocking antibodies. A highly specific antibody directed toward Axl (< 2% cross reactivity with Sky and Mer) activated Axl leading to an enhancement of TRAP and ADP induced aggregation and degranulation. Stimulation of human platelets by this Axl agonist led to a modest, but sustained increase in calcium mobilization suggesting that Axl signaling incorporated activation of PLC. The increase in calcium mobilization was sensitive to wortmannin, demonstrating that PLC activation occurred concurrent with or downstream of PI3K. Indeed, additional experiments to ascertain the intracellular mediators of Axl activity identified a two-fold increase in specific phosphorylation of Akt downstream of PI3K as well as a similar increase in phosphorylation of PLCγ. TRAP stimulation of human platelets also increased the phosphorylation levels of Akt and PLCγ in a Gas6 dependent manner as a Gas6 blocking antibody reduced the levels of Akt and PLCγ phosphorylation by 50%. Overall, these studies suggest that Gas6 enhancement of human platelet activation occurs through the low-level stimulation of the intracellular signaling molecules Akt and PLCγ, serving at the juncture of several mediators of platelet activation. These events also increase levels of cytoplasmic calcium, further supporting an enhancement of activation observed in response to low levels of known platelet agonists. Thus, platelet Gas6 functions to support platelet activation at the very early stages of the hemostatic response to injury.
The Ubiquitin Ligase Triad1 Is Involved in Myelopoiesis and Interacts with the Transcriptional Repressors Gfi1 and Gfi1b.
Authors: Van der Reijden Bert A. , Marteijn Jurgen A.F. , Van Emst Liesbeth , De Witte Theo , Jansen Joop H. 
Published: October 2019

Abstract
We identified Triad1 as a gene that is upregulated by retinoic acid during the granulocytic differentiation of acute promyelocytic leukemia cells. In normal hematopoiesis, we show that Triad1 is weakly expressed in immature CD34+ bone marrow cells, and highly expressed in mature monocytes and granulocytes. Together, this suggests that Triad1 plays a role in the differentiation of hematopoietic cells. Triad1 contains a tripartite domain including two RING fingers, indicating that this protein might function as a ubiquitin E3 ligase, catalyzing the the conjugation of ubiquitin to substrate proteins thereby marking them for targeted degradation by the 26S proteasome.
Using GST pull down experiments, we show that Triad1 binds to the ubiquitin conjugating (E2) enzymes UbcH6 and 7. In addition, immunoprecipitation of Triad1 in cells that were transfected with FLAG-tagged ubiquitin shows that Triad1 binds to ubiquitinated proteins, and that Triad1 is capable of self-ubiquitination, further corroborating the assumption that Triad1 acts as a E3 ubiquitin ligating enzyme.
To study the role of Triad1 in hematopoiesis we overexpressed the gene in primary murine bone marrow cells using a retroviral vector that contains Triad1 in front of an IRES-GFP cassette. GFP positive cells were FACS sorted and used in colony assays (CFU-GM). Compared to empty vector controls (GFP alone), Triad1 expression resulted in more than 80% inhibition of clonogenic growth. Importantly, addition of the proteasome inhibitor MG132 (10E-8 M) reversed the Triad1-induced suppression of colony formation. Furthermore, three Triad1 expression constructs in which one of the conserved cys/his residues of the TRIAD domain (essential for function) were mutated did not show the suppressive effect on colony formation. Together, these data show that Triad1 is involved in myelopoiesis and acts through the ubiquitination of specific substrate proteins.
To identify these substrates, a yeast-two-hybrid screen of a human bone marrow cDNA library was performed using the Triad1 protein as a bait. Interestingly, the transcriptional repressor Gfi1b was found to bind to Triad1. The interaction was confirmed by immunoprecipitation using GFP-Triad1 and FLAG-tagged Gfi1b transfections in mammalian cells. We show that Triad1 binds to the zinc finger region of Gfi1b. This region is very (>98%) homologous to the paralogue Gfi1. Further immunoprecipitation analyses showed that Triad1 also binds to the zinc finger region of Gfi1. Gfi1 plays an essential role in neutrophil development and Gfi1 pointmutations result in neutropenia in man. Currently, we are studying the direct ubiquitination of Gfi and Gfi1b by Triad1 in in vitro ubiquitination assays. In addition, we are studying the effect of Triad1 on the transcriptional repression of the ELA2 and other promoters by Gfi1.
The Transcription Factor Nf-E2 Is Overexpressed in Patients with Polycythemia Vera.
Authors: Goerttler Philipp S. , Maerz Edith , Steimle Cordula , Will Britta , Schmitt-Graeff Annette , Pahl Heike L. 
Published: October 2019

Abstract
Despite recent advances in characterizing molecular markers for the diagnosis of polcycythemia vera (PV), the aberrations leading to disease development remain unknown. We therefore used expression profiling to identify candidate genes involved in the pathophysiology of PV. RNA from purified granulocytes of 40 PV patients was analyzed by hybridizing individual samples to a pool of 50 healthy controls. Of the 7,496 genes represented in the cDNA array, 253 were upregulated more than 1.5 fold in PV compared to healthy controls (p< 0.01, FDR corrected). Promoters for 26 of the 253 genes overexpressed in PV are regulated by members of the Sp1 family of transcription factors. We have therefore hypothesized that altered activity of one or several Sp1-like transcription factors may contribute to the molecular etiology of PV. Here we report that one of the Sp1 target genes identified, the transcription factor NF-E2, is overexpressed in 37 of the 40 PV patients (92.5%) assayed by microarray. NF-E2 overexpression was confirmed by Northern Blot and quantitative RT-PCR analysis. Transcription factor overexpression varies from 2.3 to 40 fold, with a median increase of 7 fold in PV patients compared to healthy controls. The NF-E2 protein is readily detected in PV granulocytes by Western Blot whereas it is undetectable in healthy control cells. Immunohistochemistry revealed that in PV bone marrow, NF-E2 is overexpressed in megakaryocytes as well as erythroid and granulocytic precursors. Several published observations suggest that NF-E2 is an exceptionally promising candidate in the molecular etiology of PV. Firstly, the transcription factor is expressed in hematopoietic precursors as well as in erythroid, megakaryocytic and granulocytic cells, those lineages affected in PV. Secondly, Sayer et al. have shown that overexpression of NF-E2 in fetal liver cells leads to the development of Epo-independent erythroid colonies, analogous to the endogenous erythroid colonies (EECs) observed in PV patients. Furthermore, ectopic expression of NF-E2 results in the spontaneous emergence of morphologically mature erythroid cells in the absence of Epo and can reprogram monocytic cells towards erythroid and megakaryocytic differentiation. These data support the hypothesis that the concentration of an individual transcription factor can control lineage commitment. We thus propose that in PV patients elevated concentrations of NF-E2 alter the physiological transcription factor balance leading to an overproduction of erythroid and, in select patients, megakaryocytic cells/platelets. In this model the level of NF-E2 overexpression determines both the severity of erythrocytosis and the concurrent presence or absence of thrombocytosis.
Incorporation of Bone Marrow Derived Cells in Colonic Adenoma.
Authors: Cogle Christopher R. , Theise Neil D. , Jorgensen Marda L. , Smith Doug , Thung Swan L. , Liu Chen , Wingard John R. , Scott Edward W. 
Published: October 2019

Abstract
Bone marrow contains stem cells that can engraft in various distant organs. These observations prompted us to investigate the cellular origin of post-transplant solid tumor neoplasias found in women having received a bone marrow transplant at our facility. In women having received bone marrow transplantation from male siblings we found colonic adenomas post-transplant. Presence of donor-derived cells were examined using a combination of immunohistochemistry for cells expressing the pan-leukocyte antigen, CD45, and the colonocyte antigen, cytokeratin 20, in conjunction with fluorescent in situ hybridization for X and Y chromosomes. Confocal microscopy was used to evaluate for evidence of cell fusion. In these cases, recipients of gender-mismatched transplants showed evidence of Y-chromosome positive, cytokeratin positive cells within the adenomas. The male cells accounted for 1 to 4% of the adenoma cells in histologic section. Confocal microscopy permitted evaluation of entire nuclei (Z-stack steps of 0.25 microns) and demonstrated no male cell with more than one X chromosome. A total of 40 male cells expressing cytokeratin were found throughout the adenomas. When considering how bone marrow derived cells incorporate into colonic adenomas, two possibilities should be regarded. First, bone marrow derived cells may migrate to neoplasias due to upregulation of tumor growth factors, which also act as inflammatory cytokines and chemokines, such as stromal derived factor 1 (SDF-1). Up- or down-regulating SDF-1 has profound effects on recruiting circulating bone marrow stem/progenitor cells for engraftment as end-organ epithelia. SDF-1 staining of the colonic adenomas found in our patients demonstrated intense, patchy SDF-1 expression compared to normal colonic epithelia. Second, roving donor-derived bone marrow cells may have engulfed the recipient adenoma cells. A donor scavenger cell could have phagocytosed an apoptotic adenoma cell. In these situations the fusion of nuclear material should result in a multiplicity of sex chromosomes (XXY or XXXY). However, as noted, the donor-derived epithelial cells within the adenomas demonstrated no extra X chromosomes. In the liver, where cell fusion has been demonstrated in severe disease stress states, it has been postulated that 28% of donor-derived hepatocytes are due to reduction division, resulting in diploid daughter cells. Based on the probability of binomial distribution, the chance that we would find 40 out of 40 diploid donor-derived epithelial cells amidst a background fusion resolution rate of 28% is one in 1x10e22. Thus, direct differentiation, rather then absolutely complete and perfect resolution of every fusion event is the most likely explanation of our current findings.