Utility of genome-wide association study findings: prostate cancer as a translational research paradigm.

Genome-wide association studies have identified thousands of consistently replicated associations between genetic markers and complex disease risk, including cancers. Alone, these markers have limited utility in risk prediction; however, when several of these markers are used in combination, the predictive performance appears to be similar to that of many currently available clinical predictors. Despite this, there are divergent views regarding the clinical validity and utility of these genetic markers in risk prediction. There are valid concerns, thus providing a direction for new lines of research. Herein, we outline the debate and use the example of prostate cancer to highlight emerging evidence from studies that aim to address potential concerns. We also describe a translational framework that could be used to guide the development of a new generation of comprehensive research studies aimed at capitalizing on these exciting new discoveries.

Effect of lithium on the myelosuppressive and chemotherapeutic activities of vinblastine.

Serum concentrations of lithium after i.p. administration to normal mice declined with biphasic kinetics. Treatment of mice bearing ascitic L1210 leukemia with lithium resulted in a modest protection against the myelosuppressive effects of vinblastine. Lithium as a single agent was without effect on the survival times of mice bearing either the L1210 or P388 leukemia. Similarly, there was no evidence of significant antiproliferative or cytotoxic activity when cultured L1210 leukemia and murine neuroblastoma cells were exposed to lithium at levels comparable to those observed in the serum of lithium-treated mice. The therapeutic activity of vinblastine against the L1210 and P388 leukemias was not significantly altered by either simultaneous or subsequent administration of lithium. Lithium did not antagonize the antiproliferative or cytotoxic action of vinblastine against L1210 leukemia or murine neuroblastoma cells and was without effect in experiments with neuroblastoma cells that assessed vinblastine inhibition of a biological function dependent on formation of cytoplasmic microtubules (neurite formation induced by serum deprivation). The results obtained suggest that administration of lithium to reduce myelosuppression is not likely to counteract the tumoricidal activity of vinblastine.

Bcr-abl-positive cells secrete angiogenic factors including matrix metalloproteinases and stimulate angiogenesis in vivo in Matrigel implants.

To further elucidate the role of angiogenesis in the pathogenesis of chronic myelogenous leukemia (CML) we evaluated the effects of the bcr-abl translocation on the secretion of the angiogenic factors VEGF, FGF-2, HGF, IL-8 and matrix metalloproteinases (MMPs) as well as on the angiogenic potential in vivo of bcr-abl+ cells. First, we examined murine FL5.12 cells transfected with the bcr-abl constructs p185, p210 and p230 and found that the transfected cells secreted as much as four-fold more VEGF (p185 > p210 >p230) than wild-type (wt) cells, as well as MMP-9 and MMP-2. When Matrigel fragments containing these bcr-abl+ cells were implanted subcutaneously in SCID or Balb-C mice they became significantly more vascularized and hemoglobinized than implants containing normal or wt cells (p185 > p210 > p230). Similarly, we found that myeloblasts expanded from bone marrow (BM) CD34+ cells derived from Philadelphia-positive CML patients secreted up to 10 times more VEGF, FGF-2, HGF and IL-8 compared to myeloblasts derived from normal donors' BM CD34+ cells and that BM mononuclear cells (MNC) isolated from CML patients induced vascularization of Matrigel implants in mice. Moreover, we found that peripheral blood MNC expressed MMP-2 and membrane-type (MT)1-MMP in about 50% of CML patients studied, and MMP-9 in all of them. Furthermore, VEGF stimulated the secretion of MMP-9 in these primary CML cells. We conclude that stimulation of angiogenesis by angiogenic factors, including MMPs, could play an important role in the pathogenesis of CML, suggesting that therapies targeting the newly formed endothelium could be developed for CML.

Alveolar soft-part sarcoma presenting with eosinophilia and shunt.

Alveolar soft-part sarcoma (ASPS) is a rare soft tissue tumour found in young adults that usually arises in skeletal muscle and occurs most frequently in the lower limbs. Radiological and pathological findings of ASPS in a 34-year-old man who presented with increasing shortness of breath over a period of four to six weeks with peripheral blood eosinophilia, hypoxemia and a significant arteriovenous shunt are reported. The present article is the fourth report of eosinophilia in association with sarcoma, and the first involving ASPS.

Gynecomastia after cytotoxic therapy for metastatic testicular cancer.

Four men with metastatic nonseminomatous testicular cancer, who had received combination chemotherapy, experienced transient gynecomastia. Serum hormone levels were measured during and after the resolution of the gynecomastia. These levels indicated toxic effects on Leydig's cells and germinal epithelium concurrent with raised serum estradiol levels in the absence of tumor. The gynecomastia may have been caused by Leydig's cell dysfunction or refeeding after substantial weight loss. This benign form of gynecomastia must be recognized to avoid unnecessary investigation and treatment.

Comparison of colony stimulating activities secreted into mouse lung conditioned medium in the presence and absence of lithium chloride.

Inclusion of lithium chloride during the process of secretion of granulocyte-macrophage colony stimulating activity (CSA) into mouse lung conditioned medium resulted in an increased production of CSA. CSA produced in the presence of lithium chloride was compared to the CSA produced in its absence by means of ammonium sulfate precipitation, Sephadex G-1CO (S) chromatography, concanavalin A-Sepharose chromatography and polyacrylamide gel electrophoresis. It was found that the two activities behaved identically, indicating that lithium-induced increase in CSA does not involve a qualitative change in the molecule of the colony stimulating factor, but reflects an increased production (or release) of a CSF molecule that is similar to the one produced in its absence.

Granulocytic colonies on macrophage-coated cellulose acetate membranes (CAM) in S1/S1dmice.

The kinetics of formation of granulocytic colonies on macrophage-coated cellulose acetate membranes (CAM) were investigated in Sl/Sld mice, which have a genetic defect in their hematopoietic microenvironment. CAM were left in the peritoneal cavity of mice for 7 days to become coated with peritoneal cells. The mice were then sublethally irradiated to suppress endogenously derived granulocytic colonies, and bone marrow cells were injected i.p. within 1--2 hr irradiation. During the next 7 days, peroxidase-positive granulocytic colonies appeared on CAM. The number of colonies on CAM in Sl/Sld mice at 7 days was consistently less than that from littermate +/+ mice. Since it appeared that the CAM in the Sl/Sld provided an inferior microenvironment to that of the +/+, the effect of raising a CAM in one genotype and transferring it to another was investigated. CAM raised in +/+ or in Sl/Sld were transferred to an irradiated +/+ or Sl/Sld following which cells were injected into the secondary host and colonies determined subsequently. The number of granulocytic colonies on CAM was influenced primarily by the type of secondary host. Colony number was consistently less in the secondary Sl/Sld host than in the +/+ host whether the primary host was a Sl/Sld or a +/+. These observations confirm the concept of a microenvironmental defect in Sl/Sld mice. In addition, the studies indicate that the microenvironment on a CAM can be modified by a secondary host and suggest that "remodeling" of CAM may be a continuous, kinetic process.

Phenotypic characterization of the human fibrous histiocytoma giant cell tumor (GCT) cell line and its cytokine repertoire.

The pleiotropic nature of malignant fibrous histiocytomas (MFH) is manifested as mixed cellular infiltrates consisting of myofibroblasts, histiomonocytes, and neutrophils. We detail in this report the phenotypic characteristics of the human fibrous histiocytoma giant cell tumor (GCT) cell line that establish its mesenchymal origin. The latter is underscored by the ability of GCT cells to express mRNA for transforming growth factor beta (TGF-beta) as well as both A and B chains of platelet-derived growth factor (PDGF). GCT cells also support the binding of CD34+ cells, but less efficiently than do normal marrow stromal cells. Since cytokines elaborated by MFH may mediate in part the recruitment of monocytes and neutrophils into tumor-infiltrated tissues, we have determined the cytokine repertoire of the GCT cell line, already known for its ability to elaborate colony-stimulating factors (CSFs) and interleukin-1 (IL-1). GCT cells express IL-1 alpha, IL-1 beta, IL-6, macrophage colony-stimulating factor (M-CSF or CSF-1), granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF), and IL-8. No detectable mRNA for IL-3, IL-4, IL-7, and tumor necrosis factor-alpha (TNF-alpha) was detected in GCT cells by polymerase chain reaction (PCR). Expression of cytokine mRNAs was responsive to agents such as dexamethasone (dex), 12-O-tetradecanoyl phorbol 13-acetate (phorbol diester or TPA), and TNF-alpha. Thus, this cell line provides a useful model for understanding the pathobiology of MFH and hematopoietic progenitor interactions with mesenchymal/stromal cells.

Long-term outcome of a pediatric-inspired regimen used for adults aged 18-50 years with newly diagnosed acute lymphoblastic leukemia.

On the basis of the data suggesting that adolescents and young adult patients with acute lymphoblastic leukemia (ALL) have improved outcomes when treated on pediatric protocols, we assessed the feasibility of treating adult patients aged 18-50 years with ALL with the DFCI Pediatric ALL Consortium regimen utilizing a 30-week course of pharmacokinetically dose-adjusted E. coli L-asparaginase during consolidation. Between 2002 and 2008, 92 eligible patients aged 18-50 years were enrolled at 13 participating centers. Seventy-eight patients (85%) achieved a complete remission (CR) after 1 month of intensive induction therapy. With a median follow-up of 4.5 years, the 4-year disease-free survival (DFS) for the patients achieving a CR was 69% (95% confidence interval (CI) 56-78%) and the 4-year overall survival (OS) for all eligible patients was 67% (95% CI 56-76%). The 4-year DFS for the 64 patients who achieved a CR and were Philadelphia chromosome negative (Ph-) was 71% (95% CI 58-81%), and for all 74 Ph- patients the 4-year OS was 70% (95% CI 58-79%). We conclude that a pediatric-like treatment strategy for young adults with de novo ALL is feasible, associated with tolerable toxicity, and results in improved outcomes compared with historical regimens in young adult patients with ALL.

Stimulation of [3H]thymidine uptake in mouse marrow by granulocyte-macrophage colony stimulating factor from mouse lung conditioned medium.

Stimulation of [3H]thymidine uptake in mouse marrow cells by a haematopoietic factor, granulocyte-macrophage colony stimulating factor from mouse lung conditioned medium, was used to follow the activity of the factor in the medium, and during its partial purification from the medium. The assay was performed in microtitre plates and found to be much easier and faster than conventional colony counting. The marrow cells were incubated in flat-bottomed plates in the presence of the factor for 5 days before labelling with [3H]thymidine (2 muCi/well, 5 Ci/mmole) for 6 h. Stimulation of the [3H]thymidine uptake was compared with the development of granulocyte-macrophage colonies in semisolid methylcellulose culture. The activity followed by both assays showed identical behaviour when subjected to ammonium sulphate precipitation, Sephadex gel filtration, concanavalin-A-Sepharose chromatography and polyacrylamide gel electrophoresis.

Identification of a hypoxic population of bone marrow cells.

A technique using collagenase has been devised to release and separate, with reproducibility, hematopoietic cells (HC) from various microenvironments of mouse femurs. HC were assayed by an in vitro gel culture technique used traditionally to score granulocyte-macrophage precursor cells (CFU-C). CFU-C which resided in the medullary cavity and endosteal regions were sensitive to ionizing radiation and resistant to misonidazole (MISO) cytotoxicity. CFU-C which resided within the compact bone were resistant to ionizing radiation and sensitive to the cytotoxic action of MISO. These results suggest that HC which reside in the bone are hypoxic and retain clonogenic potential. When animals were exposed to various treatments with MISO followed by myelotoxic doses of cyclophosphamide (CTX) or total body irradiation (TBI), the LD50 of both agents was significantly reduced. This result suggests that a hypoxic component of HC could be important in the regenerative process within the marrow after such myelotoxic trauma.

Misonidazole enhances cyclophosphamide toxicity to bone marrow.

Normal bone marrow function was surveyed in animals that received cyclophosphamide after treatment with small, multiple doses of misonidazole. Peripheral blood white cell counts, cell differentials, hematocrits, bone marrow white cell counts and committed granulocyte-macrophage precursors (CFUc) were monitored for several days following treatment with misonidazole and cyclophosphamide. When results obtained from animals treated with physiological saline or misonidazole in advance of cyclophosphamide were compared, no significant differences were noted in routine assays of white blood cell count, cell morphology or hematocrit. Pre-treatment with misonidazole, however, caused a significant reduction in survival and delay in recovery of bone marrow CFUc (p less than .01). The combined use of misonidazole and cyclophosphamide also reduced animal survival (DMF = 1.2), with the majority of deaths being attributable to failure of normal hematopoietic function. These results suggest that misonidazole enhances the myelotoxicity associated with cyclophosphamide use. This additional damage is not detectable using routine hematological assays, but is demonstrable in assays of bone marrow stem cells and animal survival studies.

High dose misonidazole with dexamethasone rescue: a possible approach to circumvent neurotoxicity.

With a view to modifying misonidazole (MISO) neurotoxicity, we initiated a randomized clinical study to assess a possible drug interaction and toxicity protection when dexamethasone (DXM) is administered concomittantly with MISO. The ongoing study consists of: 1. Pharmacokinetic evaluation; 2. Assessment of toxicity. Fourteen patients undergoing radiation therapy for different types of malignant neoplasia (excluding brain tumors) have been randomized to receive either MISO alone, or DXM one week prior and during treatment with MISO. Five of seven patients receiving MISO alone developed peripheral neuropathies while only one out of 7 patients that received MISO with DXM coverage developed a transient and mild neuropathy. Pharmacokinetic evaluation of MISO in plasma and urine of those patients receiving DXM has shown no evidence of drug interaction. It is postulated that the mechanism of action of DXM is at the nerve cell membrane level, restoring and stabilizing cell surface properties. In future studies we will investigate the use of DXM with increasing doses of MISO above the recommended maximum dose of 12 gm/m2, hoping to achieve a higher tumor tissue level of MISO while avoiding unacceptable toxicity. The effect of Allopurinol on the plasma kinetics of MISO was studied in four additional patients, observing also no evidence of drug interaction.

Suppression of hepatic hematopoiesis with radioactive gold (198Au).

A patient with idiopathic myelofibrosis of some 20 yr duration developed esophageal varices and ascites. No explanation for increased portal pressure other than hepatic hematopoiesis was found. Consequently, a trial of cobalt irradiation to the liver was undertaken with definite but transient decrease in ascites. Subsequently, two courses of radioactive colloidal gold were given, again with definite but transient beneficial effects on the degree of ascites. This latter benefit occurred without suppression of marrow function.

Induction of the expression of HLA class I antigens on K562 by interferons and sodium butyrate.

Using sodium butyrate and alpha, beta, and gamma interferons as inducing agents it has been possible to demonstrate the triggering of HLA class I antigen synthesis in the K562 cell line. This cell line, widely used to study hemopoietic differentiation, does not naturally express HLA antigens. This effect was confirmed by the detection of HLA class I antigens on the cell membrane with specific monoclonal antibodies, by immuneprecipitation, and by isolation of specific HLA ABC messenger RNA, in the induced cells. No synthesis of HLA class II antigens was observed. Because leukemic cells can be considered as a model representing certain stages of normal hemopoietic differentiation, the expression of HLA antigens on K562 cells induced to differentiate could be interpreted as an event related to the process of differentiation itself. The lack of expression of DR antigens may result from a genetic defect as observed for beta 2-microglobin in Daudi cells.

Monoclonal antibodies against human granulocytes and myeloid differentiation antigens.

Monoclonal antibodies (MCA) were obtained by immunizing BALB/c mice with 99% pure granulocytes from normal donors or with a whole leukocyte suspension obtained from a chronic myelogenous leukemia (CML) patient, and then fusing the mouse spleen cells with a 315-43 myeloma cell clone. Four MCA were selected and studied using ELISA, immunofluorescence, cytotoxicity assays, and FACS analysis. Antibodies 80H.1, 80H.3, and 80H.5 (from normals) and 81H.1 (from CML) detected antigens expressed on neutrophils. Antibodies 80H.1 and 80H.3 (IgG) also reacted with monocytes but not with other blood cell subsets. Antibodies 80H.5 and 81H.1 (IgM) were cytotoxic and reacted strongly with most of the cells of the neutrophil maturation sequence, i.e., myeloblasts, promyelocytes, myelocytes, and mature granulocytes. Antibodies 80H.5 and 81H.1 also inhibited CFU-GM growth stimulated by leukocyte feeder layers or placental conditioned media, but did not inhibit BFU-E and CFU-E. Antigens recognized by 80H.3, 80H.5, and 81H.1 were expressed both on a proportion of cells from HL.60, KG.1, ML.1, and K562 myeloid cell lines, and on a proportion of blast cells isolated from patients with acute myelogenous leukemia. They were not found on lymphoid cell lines or lymphoid leukemia cells. These MCA recognize either late differentiation antigens expressed on mature neutrophils and monocytes (80H.1 and 80H.3) or early differentiation antigens (80H.5 and 81H.1) specific to the granulocytic lineage. They may be useful for a better definition of those antigens specific to hematopoietic stem cells and their relationship with normal or neoplastic hematopoiesis.

The hematopoietic protective effect of bacterial endotoxin prior to nitrogen mustard in the mouse and dog.

Bacterial endotoxin was given to mice 24 h before nitrogen mustard (HN2). Total nucleated cells and peroxidase positive cells/humerus were significantly higher during the recovery phase in endotoxin-treated mice compared to controls given HN2 alone. Endotoxin was also given prior to HN2 in dogs, and a suggestive hematopoietic protective effect was found.

Second allogeneic transplants for leukemia using blood instead of bone marrow as a source of hemopoietic cells.

There is increasing interest in blood cell transplants (BCT) from normal donors as an alternative to BMT. Ten patients with relapsed or persistent leukemia after BMT received intensive cytotoxic conditioning followed by allogeneic BCT. Three BCT were from single-antigen mismatched donors; two of the corresponding recipients had rejected a BMT from the same donor. Two patients received BCT from a different donor (one matched, one single-antigen mismatched). The other six BCT were from the same, fully matched, bone marrow donors. Donors were given G-CSF to mobilize progenitor cells which were collected by a single 2-4 h leukapheresis. Methotrexate, CsA and folinic acid were used for GVHD prophylaxis for all transplants but CsA was discontinued sooner after BCT than after BMT. One patient died without engraftment having rejected a BMT from the same single-antigen mismatched donor 4 years previously. Nine patients had granulocyte recovery at a median of 14 days, up to 6 days faster than with their previous BMT. Platelet recovery was also 2-6 days faster than with BMT in four previously engrafting patients. Four patients died without platelet recovery after BCT within a year of BMT, three of treatment-related toxicity and one of relapse. Two patients developed grade II acute GVHD. Of six patients given BCT more than a year from BMT, four, all with acute leukemia, survive 7, 14, 29 and 29 months after BCT and one relapsed at 7 months. All four survivors developed chronic GVHD. These results indicate that BCT may be useful therapy for relapse occurring more than a year after BMT.

Unrelated donor BMT recipients given pretransplant low-dose antithymocyte globulin have outcomes equivalent to matched sibling BMT: a matched pair analysis.

Fifty-seven patients receiving unrelated donor (UD) BMT were matched for disease and stage with 57 recipients of genotypically matched related donor (MRD) BMT. All UD recipients were matched serologically for A and B and by high resolution for DR and DQ antigens. All patients received CsA and 'short course' methotrexate with folinic acid. Unrelated donor BMT patients also received thymoglobulin 4.5 mg/kg (6 mg/kg if <30 kg) in divided doses over 3 days pretransplant. For UD and RD BMT, respectively, incidence of acute GVHD grade II-IV was 19 +/- 6% vs 36 +/- 8%, grade III-IV 10 +/- 6% vs 18 +/- 7%, chronic GVHD 44 +/- 8% vs 51 +/- 8%, non-relapse mortality 15 +/- 5% vs 8 +/- 4% at 100 days, 28 +/- 8% vs 36 +/- 7% at 3 years. At 3 years, relapse was 45 +/- 7% vs 42 +/- 7%, and disease-free survival 39 +/- 7% vs 37 +/- 7%. None of these differences are significant. Three-year overall survival was identical at 42 +/- 7%. For 29 patients with low/intermediate risk leukemia, disease-free survival was 68 +/- 10% after UD BMT vs 59 +/- 9% for RD BMT recipients (P = NS). Corresponding figures for high risk patients were 14 +/- 7% and 21 +/- 8%, respectively. We conclude that UD BMT recipients matched as above and given pretransplant ATG have similar outcomes to recipients of MRD BMT using conventional drug prophylaxis. Unrelated donor BMT should be considered in any circumstance where MRD BMT is routine.

Partially mismatched blood cell transplants for high-risk hematologic malignancy.

Eleven patients with high-risk hematologic malignancy received cryopreserved but otherwise unmanipulated blood cell transplants (BCT) from partially mismatched family members in whom progenitor cells had been mobilized by G-CSF. Donors were mismatched by up to one antigen in the GVH direction and up to three antigens in the rejection direction. Outcomes were compared with those of 22 patients receiving BCT from fully matched donors. Two mismatched patients died without engraftment on day 21 and 32. One had rejected bone marrow from the same donor, the other was mismatched by two antigens in the rejection direction and received the lowest dose of CD34+ cells. Median time to granulocyte engraftment was 21.5 (range 16-33) days for the mismatched group compared with 16 (11-28) days for the matched group (P = 0.01). No correlation was found between CD34+ cell dose and time to granulocyte or platelet recovery. In the mismatched and matched BCT groups respectively, the risk of grade II-IV acute graft-versus-host disease (GVHD) was 73% vs 28% (P = 0.001) and of chronic GVHD 100% vs 78% at 18 months (P = 0.01). The relationship of T cell dose to acute GVHD could only be evaluated in the matched group and no correlation was found. One of 11 mismatched patients and eight of 22 matched patients had relapse or persistent disease. Disease-free survival at 1 year was similar at 55% for mismatched and 50% for matched BCT. These results indicate that allogeneic BCT from partially mismatched family members is accompanied by a high incidence of GVHD but may result in comparable survival to BCT from fully matched donors.