Etoposide and illegitimate DNA double-strand break repair in the generation of MLL translocations: new insights and new questions.

Faithful repair of chromosomal double-strand breaks (DSBs) is central to genome integrity and the suppression of genome rearrangements including translocations that are a hallmark of leukemia, lymphoma, and soft-tissue sarcomas [B. Elliott, M. Jasin, Double-strand breaks and translocations in cancer, Cell. Mol. Life Sci. 59 (2002) 373-385; D.C. van Gent, J.H. Hoeijmakers, R. Kanaar, Chromosomal stability and the DNA double-stranded break connection, Nat. Rev. Genet. 2 (2001) 196-206]. Chemotherapy agents that target the essential cellular enzyme topoisomerase II (topo II) are known promoters of DSBs and are associated with therapy-related leukemias. There is a clear clinical association between previous exposure to etoposide and therapy-related acute myeloid leukemia (t-AML) characterized by chromosomal rearrangements involving the mixed lineage leukemia (MLL) gene on chromosome band 11q23 [C.A. Felix, Leukemias related to treatment with DNA topoisomerase II inhibitors, Med. Pediatr. Oncol. 36 (2001) 525-535]. Most MLL rearrangements initiate within a well-characterized 8.3 kb region that contains both putative topo II cleavage recognition sequences and repetitive elements leading to the logical hypothesis that MLL is particularly susceptible to aberrant cleavage and homology-mediated fusion to repetitive elements located on novel chromosome partners. In this review, we will discuss the findings and implications of recent attempts to confirm this hypothesis.

Risk of chemotherapy-induced pulmonary fibrosis is associated with polymorphic tumour necrosis factor-a2 gene.

In some patients, chemotherapy (CHT) of cancer can result in pulmonary inflammation and fibrosis, eventually leading to respiratory insufficiency. As animal studies have underlined the importance of major histocompatibility complex (MHC) genes in the susceptibility to bleomycin (BLM)-induced pulmonary fibrosis, the authors typed human leukocyte antigen-DR (HLA-DR) and tumor necrosis factor (TNF) genes in patients treated for Hodgkin's disease by a therapy including bleomycin. Patients were divided into pulmonary responders (PR) (n=21) or nonresponders (PNR) (n=20) on the basis of pulmonary alterations detected on chest radiography and the cumulated amount of BLM injected. The incidence of TNFa2, a microsatellite allele in the promoter region of the TNFB gene reported to be associated with increased TNF-a production, was significantly higher in PR than PNR (65% versus 19%). HLA-DRB1*15 showed a weak but nonsignificant association with the PR phenotype (50% versus 14%), as well as HLA-DRB1*03 (30% versus 19%) and TNFA-308*2 (30% versus 14%). TNFa2 and DR15 were independent risk factors and the occurrence of either genetic marker was 85% versus 29% in the PR and PNR groups respectively. Thus, the polymorphic TNFa2 microsatellite is associated with a risk of chemotherapy-induced pulmonary fibrosis.

New T-lymphocytic cell lines for studying cell infectability by human immunodeficiency virus.

We identified five human T-lymphoid cell lines (PB-1, Sez-4, C19PL, HUT 102B and ATL-2) which highly express CD4 in addition to CXCR4 and CCR5. In order to evaluate if these cells are infectabile by human immunodeficiency virus (HIV) and could be employed as a model in HIV research we exposed these cell lines to X4 (T-cell tropic) and R5 (macrophage tropic) and subsequently tried to correlate their infectability with (i) level of chemokine coreceptor (CXCR4 and CCR5) expression, (ii) coreceptor functionality (calcium flux, chemotaxis and phosphorylation of MAPK p42/44 and AKT) and (iii) endogenous expression and secretion of HIV-related chemokines which compete with the virus for binding to CXCR4 (SDF-1/CXCL12) or CCR5 (MIP-1beta/CCL4, MIP-1alpha/CCL3, RANTES/CCL5, MCP-2/CCL8, MCP-3/CCL7 and MCP-4/CCL13). We demonstrated that while PB-1 cells are infectable by both X4 and R5 HIV, Sez-4, C91PL, HUT 102B and ATL-2 cells were infected by X4 HIV only. Moreover, we noticed that the susceptibility of these cells to HIV did not correspond either with the level of surface expression or with the functionality of CXCR4 or CCR5; however, it was modulated to some degree by the endogenously secreted HIV-related chemokines. Thus all five mature T-cell lines described here may provide useful new models for studying various aspects of HIV infection. In addition we demonstrate that the infectability of cells by HIV is modulated by so far unidentified intrinsic factors as well as some already known endogenously secreted chemokines. The identification of these factors may be important for developing new strategies to protect cells from HIV infection.

Anemia: an indicator for malnutrition in the elderly.

The prevalence of anemia increases with age and is frequently multifactorial. We postulated that malnutrition contributes to anemia in the elderly and is underdiagnosed. Our objective was to analyze the prevalence of anemia and its association with nutritional status in a hospitalized geriatric population. Included in this retrospective cohort study were 186 consecutive patients admitted in 1997 to a geriatric unit of a university hospital. We compared hematological and chemical blood tests routinely performed upon admission in patients with anemia (hemoglobin <120 g/l) and without anemia (hemoglobin > or = 120 g/l). Using these admission parameters, we defined a multiparameter score of malnutrition by low lymphocyte counts, decreased values of albumin, cholesterol, transferrin, cholinesterase, and zinc, iron deficiency by low transferrin saturation and normal C-reactive protein, and inflammation by increased C-reactive protein and high transferrin saturation. Of the 186 patients, 82 (44%) met the criteria for anemia on admission. In univariate analysis, patients with anemia differed significantly from patients with normal hemoglobin exhibiting lower serum values of albumin, iron, transferrin, cholesterol, cholinesterase, zinc, transferrin saturation, and lymphocyte count and higher C-reactive protein levels. Using a multiparameter score, anemia correlated significantly with parameters of malnutrition (P=0.0001) but not with iron deficiency (P=0.5) or with inflammation (P=0.08). In a multivariate logistic regression model, anemia was significantly associated with serum albumin (RR: 1.138; 95% CI: 1.056-1.227; P=0.0007), cholinesterase (RR: 1.387; 95% CI 1.122-1.714; P=0.0025), and transferrin saturation (RR: 1.05; 95% CI: 1.012-1.09; P=0.009). We conclude that malnutrition may play an important etiologic role in anemia in the elderly.

Morphological parameters of the angiogenic response in pancreatic ductal adenocarcinoma--correlation with histological grading and clinical data.

The aim of this study was to evaluate angiogenesis in tissue of the pancreatic ductal adenocarcinoma and to correlate it with histopathological data such as tumour differentiation, tumour size, lymph node metastasis and patients survival. Tumour samples obtained during surgery from 36 patients were immunostained for the presence of blood vessels with monoclonal antibody against the CD31 molecule. Evaluation of microvasculature was perfomed by counting the microvessel density (MVD) in selected areas under light microscope as well as by computer assisted image analysis (CAIA). In the latter, the following parameters were used for assessment of microvessels: mean number/field, mean area of the vessels, total area/field and total perimeter/field. MVD values obtained under optical microscope and with CAIA were highly correlated. All parameters characterising microvasculature in CAIA also revealed a significant correlation with the histological grading of tumours; generally the less differentiated tumours manifested more extensive vascular network. No significant relationship was found between the tumour size and any of the CAIA parameters. The area of vessels (both total and mean values) revealed a significant, inverse correlation with the incidence of lymph node metastases. The same type of correlation was also found between the mean vessel area and the postoperative survival period. The results show that CAIA of microvessels offers new parameters with some predictive value for the outcome of patients with pancreatic cancer.

Graft-versus-myeloma after withdrawal of immunosuppression following allogeneic peripheral stem cell transplantation.

There is growing evidence for a graft-versus-myeloma effect following allogeneic stem cell transplantation. We add to this evidence by reporting complete remission achieved by withdrawal of immunosuppression in a patient with multiple myeloma progressing after HLA-identical sibling peripheral stem cell transplantation. De novo chronic graft-versus-host disease coincided with the anti-myeloma effect and responded to treatment. The patient remains in complete remission 3 years after transplant.

In vitro toxicity studies with mitomycins and bleomycin on endothelial cells.

Pulmonary side effects are increasingly observed as dose-limiting toxicity (DLT) of cancer treatment. The available preclinical models have a limited predictive value for lung toxicity in humans. We have attempted to elucidate potential mechanisms involved in these reactions, by studying the effects on cells, possibly involved in these reactions after in vitro exposure to drugs with known lung toxic effects. We have investigated the effects of bleomycin (BLM), mitomycin C (MMC), KW-2149 and its two known metabolites, M16 and M18, on oxygen radical production by granulocytes, on cytokine production: interleukin (IL)-6, transforming growth factor (TGF)-beta, tumor necrosis factor (TNF)-alpha by a human macrophage cell line (THP-1), by human endothelial cells (HVEC and HMEC) and a human colorectal cancer cell line (DLD-1), and on the cytotoxicity on endothelial cells in both confluent and non-confluent culture. The generation of oxygen radicals by normal and pre-stimulated granulocytes was not increased after preincubation with any of the drugs, at the concentrations tested. None of the cytokines (IL-6, TNF-alpha or TGF-beta) was found significantly increased in culture medium after exposure to any of the mitomycins. This was in contrast with the effect of BLM incubation, causing a rise in TGF-beta concentration. Both types of endothelial cells showed a dose-dependent, exposure duration-dependent, proliferation inhibition for all agents tested. This inhibitory effect was clearly proliferation dependent as shown by the increased inhibition in semi-confluent as opposed to confluent endothelial cell cultures. Both mitomycins tested were more cytotoxic than BLM to both confluent and proliferating endothelial cells.

Influence of investigator experience and microscopic field size on microvessel density in node-negative breast carcinoma.

In this study on the determination of intratumoral microvessel density (MVD) in breast cancer, we have investigated the influence of the observer experience and the microscopic field size. We have used the sample set reported on earlier in the J Natl Cancer Inst 87: 1797-1798, 1995. This case-control study has shown a positive association of high MVD and unfavorable outcome when comparing node-negative pT1-2 breast carcinoma (NNBC) patients with a disease-free period of over ten years with those with an early distant relapse. Tumor sections of both outcome groups (favorable: n = 19; unfavorable: n = 19) were immunostained for factor VIII related-antigen (FVIII r-Ag). Microvessels were counted in the areas of most intense vascularization ('hot spots'), both at magnification x 200 (field size of 0.61 square mm) and x 400 (field size of 0.15 square mm), by one inexperienced and three experienced observers. Microphotographs of individual vascular hot spots were analyzed using overlays resembling the two field sizes. The main results obtained are: i) a confirmation of the prognostic value of microvessel density in the case-control sample set (n = 38) was established by all experienced but not by the unexperienced investigator; ii) both at x 200 and x 400 magnification, angiogenesis quantification in vascular hot spots contained prognostic information. The results of this study indicate that the selection of vascular hot spots in tumor sections immunostained for an antigen expressed on endothelial cells is more prone to inter-observer variability and more dependent on training than the counting of the microvessels within predefined hot spots itself. The microscopic magnification and resulting field size do not influence the prognostic significance of MVD in NNBC. This information validates the development of more objective methods of measuring the amount of angiogenesis within malignant tissue. This will allow more accurate implementation of the angiogenesis parameter in multiparametric and prospective prognostic factor studies in NNBC.