Synthesis and biological activities of indolocarbazoles bearing amino acid residues

Three indolocarbazole compounds bearing a tripeptide or a lysine group attached to one of the indole nitrogens via a propylamino chain and two rebeccamycin derivatives bearing a lysine residue on the sugar moiety were synthesised with the aim of improving the binding to DNA and the antiproliferative activities. Four tumour cell lines, from murine L1210 leukemia, human HT29 colon carcinoma, A549 non-small cell lung carcinoma and K-562 leukemia, were used to evaluate the cytotoxicity of the drugs. Their effects on the cell cycle of L1210 cells and their antimicrobial properties against two Gram-positive bacteria Bacillus cereus and Streptomyces chartreusis, a Gram-negative bacterium Escherichia coli and a yeast Candida albicans were also investigated.

Altered HLA-G transcription in pre-eclampsia is associated with allele specific inheritance: possible role of the HLA-G gene in susceptibility to the disease

Pre-eclampsia is a disorder of human pregnancy occurring in 5-10% of all births, and represents the leading cause of infant morbidity and mortality and maternal death. In pre-eclampsia, invasion of fetal trophoblasts into maternal arteries during early pregnancy is shallow or absent. Here we examined the hypothesis that HLA-G, a non-classical class I HLA expressed in cytotrophoblasts, may act as a key gene in pre-eclampsia. We analysed HLA-G at the level of transcription and genotyped a silent CAC-CAT polymorphism in exon 3 and a 14-bp insertion/deletion in the 3' untranslated region. A deficit in levels of the HLA-G3 transcript was observed in mild pre-eclampsia compared to normal placentas. The distribution of HLA-G polymorphisms was different between normal and pre-eclampsia samples. A correlation between the alteration in transcription of the HLA-G gene and certain HLA-G genotypes was also observed. Thus we provide the first evidence for a possible role of HLA-G in genetic susceptibility to, and pathogenesis of pre-eclampsia.

Norepinephrine-induced aortic hyperplasia and extracellular matrix deposition are endothelin-dependent

BACKGROUND

Sympathetic hyperactivity is observed in several disease states and may contribute to cardiovascular hypertrophic remodeling. Endothelin has been suggested to be a mediator of hypertrophy.

OBJECTIVE

To examine the involvement of endothelin in maintaining the growth response induced by exogenous norepinephrine.

DESIGN AND METHODS

Rats were treated with norepinephrine (2.5 microg/Kg per min subcutaneously) for 2 and 4 weeks, alone or in association with the selective endothelin-A (ETA) receptor antagonist, darusentan (LU135252, 30 mg/Kg per day orally) for weeks 3 and 4.

RESULTS

Increases in medial cell number and accumulation of collagen and elastin characterized norepinephrine-induced aortic remodeling. These effects occurred without marked changes of mean arterial pressure, but may be related to enhanced pressure variability in addition to direct effects of norepinephrine. Inhibition of ETA receptors by darusentan reversed aortic alterations produced by infusion of norepinephrine. Evaluation of medial apoptosis did not reveal any significant change in any group at 4 weeks.

CONCLUSIONS

Antagonism of ETA receptors effectively and rapidly reversed norepinephrine-induced aortic structural and compositional changes, suggesting a central role of endothelin in mediating this response. Thus, ETA receptor antagonists may help to regress large artery remodeling in conditions of increased circulating catecholamine concentrations.

Transient involvement of endothelin in hypertrophic remodeling of small arteries

OBJECTIVE

This study was designed to evaluate the capacity of norepinephrine (NE) to induce hypertrophic remodeling of small arteries in rats, and to determine the involvement of endothelin (ET) to initiate and maintain it.

DESIGN AND RESULTS

Treatment with NE (2.5 microg/kg per min) for 14 or 28 days produced a similar inward hypertrophic remodeling, characterized by a smaller lumen, but increased media thickness and cross-sectional area. Arterial stiffness was reduced. Histological evaluation confirmed the hypertrophic nature of remodeling. Concomitant administration of LU135252 (ET-receptor antagonist) for the first 14 days of NE administration prevented the development of hypertrophy, without altering arterial mechanics. Treatment with the same antagonist from day 14 to day 28 of NE or angiotensin II (Ang II) treatment failed to regress established vascular hypertrophy. In contrast, normalization of arterial structure was observed with prazosin, an alpha-adrenergic blocker. Endothelin content in small mesenteric arteries showed a transient elevation following chronic NE administration.

CONCLUSIONS

Increased circulating NE levels are associated with hypertrophic remodeling of small arteries, in which ET plays an initiating role. However, the maintenance of vascular hypertrophy is ET-independent, either in the presence of augmented circulating levels of NE or Ang II. Thus, early rather than late treatment with ET-receptor antagonists may be a preferable approach to limit small artery-mediated end-organ damage in cardiovascular diseases.

HLA-G: a shield against inflammatory aggression

Recent developments in the field of HLA-G research have revealed that, besides its involvement during pregnancy, HLA-G is expressed in peripheral tissues during pathological processes, such as viral infections, malignancies and organ transplantation. Here, we discuss recent findings regarding the influence of HLA-G on the T helper (Th) cytokine balance (favoring Th2-type responses), and the expression of HLA-G during chronic, cutaneous inflammatory diseases, such as psoriasis and atopic dermatitis. We propose a novel role for HLA-G as a tissue-protective molecule in inflammatory responses.

Phosphatidylserine increase in rat liver endomembranes during the acute phase response

The acute phase response (APR) is responsible for great changes in protein and lipid metabolism. For example, marked changes are observed in the metabolism of fatty acids, triglycerides, cholesterol and sphingolipids. Those lipids are partly recovered in the lipoproteins and subsequently in the plasma. Beside these lipid families, nothing is known about phospholipids and their synthesis in endomembranes during the APR. Our studies show that phosphatidylserine synthesis is stimulated during the APR and that this lipid is increased in the endoplasmic reticulum (ER) and the ER-derived vesicles.

Allogeneic hematopoietic stem-cell transplantation after nonmyeloablative preparative regimens: impact of pretransplantation and posttransplantation factors on outcome

PURPOSE

To analyze the impact of pre- and posttransplantation factors on the outcome of allogeneic transplantation after nonmyeloablative conditioning regimens.

PATIENTS AND METHODS

Ninety-two allogeneic transplantations after nonmyeloablative preparative regimens were reported to the Société Française de Greffe de Moelle Registry registry. Initial diagnoses were lymphoid diseases (n = 22), myeloma (n = 14), acute leukemia and myelodysplasia (n = 41), chronic myelogenous leukemia (n = 12), and solid tumors (n = 3). Forty-six patients had previously received a transplant, and 49 had progressive disease before transplantation. Three types of conditioning regimens were used with fludarabine or antithymocyte globulins. Eighty-nine patients underwent transplantation, 60 from peripheral-blood progenitor cells. Eighty-six patients received graft-versus-host disease (GHVD) prophylaxis for a median duration of 53 days.

RESULTS

Seventy-nine patients engrafted, with 40 complete and 21 mixed chimerisms. The acute GHVD rate at 3 months was 50% +/- 11%. Fifty-two patients achieved complete remission and 12, partial remission. At 18 months after transplantation, the overall survival (OS) and the transplant-related mortality (TRM) were 32% +/- 12% and 38% +/- 14%, respectively. Initial diagnosis and disease status before transplantation significantly influenced survival. Age and GHVD prophylaxis type significantly influenced TRM. We also showed an impact of GHVD prophylaxis duration on OS and TRM. In multivariate analysis, three factors remained of prognostic value on OS: initial diagnosis, disease status at transplantation, and GHVD prophylaxis duration.

CONCLUSION

This series shows encouraging results from nonmyeloablative conditioning regimens before allotransplantation and demonstrates the impact of some pre- and posttransplantation factors on outcome after transplantation.

Triple helix-forming oligonucleotides conjugated to indolocarbazole poisons direct topoisomerase I-mediated DNA cleavage to a specific site

Topoisomerase I is an ubiquitous DNA-cleaving enzyme and an important therapeutic target in cancer chemotherapy for camptothecins as well as for indolocarbazole antibiotics such as rebeccamycin. To achieve a sequence-specific cleavage of DNA by topoisomerase I, a triple helix-forming oligonucleotide was covalently linked to indolocarbazole-type topoisomerase I poisons. The three indolocarbazole-oligonucleotide conjugates investigated were able to direct topoisomerase I cleavage at a specific site based upon sequence recognition by triplex formation. The efficacy of topoisomerase I-mediated DNA cleavage depends markedly on the intrinsic potency of the drug. We show that DNA cleavage depends also upon the length of the linker arm between the triplex-forming oligonucleotide and the drug. Based on a known structure of the DNA-topoisomerase I complex, a molecular model of the oligonucleotide conjugates bound to the DNA-topoisomerase I complex was elaborated to facilitate the design of a potent topoisomerase I inhibitor-oligonucleotide conjugate with an optimized linker between the two moieties. The resulting oligonucleotide-indolocarbazole conjugate at 10 nM induced cleavage at the triple helix site 2-fold more efficiently than 5 microM of free indolocarbazole, while the other drug-sensitive sites were not cleaved. The rational design of drug-oligonucleotide conjugates carrying a DNA topoisomerase poison may be exploited to improve the efficacy and selectivity of chemotherapeutic cancer treatments by targeting specific genes and reducing drug toxicity.

[Autologous peripheral blood selected CD34+ cell transplantation in the treatment of multiple myeloma]

OBJECTIVE

To investigate the clinical impact of CD(34)(+) cell selected autologous peripheral blood stem cell transplantation (APBSCT) in multiple myeloma (MM).

METHODS

The hematopoietic recovery time, treatment efficacy, survival rate, transplantation related morbidity and the cost were compared between 21 MM patients receiving CD(34)(+) APBSCT and 21 MM patients receiving unselected APBSCT. The age and beta(2) microglobulin level at diagnosis and disease status at the time of transplantation were similar in the two groups. The induction treatment and conditioning regimen were the same.

RESULTS

Significantly lower CD(34)(+) cells were infused in the selected group as compared with the control group: 2.2 (0.5 - 14.3) x 10(6)/kg vs 9.4 (1.1 - 15.0) x 10(6)/kg, (P < 0.001). The median times to neutrophil >or= 0.5 x 10(9)/L and platelet >or= 20 x 10(9)/L were 10 and 9 days for the selected group, and 9.5 (P = 0.357) and 4.5 days (P = 0.005) for the control group, respectively. Response rates were similar in both groups (85.7% for the selected group vs 90.4% for the control group). Three year disease-free survival (32% for the selected group vs 39% for the control group) and overall survival rates (85% for the selected group vs 79% for the control group) were not significantly different. Furthermore, unselected APBSCT could reduce the cost for the transplantation.

CONCLUSION

It shows that CD(34)(+) cell selected autologous transplantation is more expensive and does not improve the clinical outcome of patients with MM.

Longitudinal study of bacterial, viral, and fungal infections in adult recipients of bone marrow transplants

The epidemiology of infections was studied in a retrospective cohort of 446 recipients of bone marrow transplants (BMTs; 92 of which were allogeneic and 354 of which were autologous) during 1993--1996. Infections that were microbiologically documented in 274 recipients included bacteremia, urinary tract infections, cytomegalovirus viremia, fungemia, invasive aspergillosis, and catheter-related infections. During the period of neutropenia, no differences were found between recipients of allogeneic BMTs and recipients of autologous BMTs with regard to the incidence and the nature of infection. After patients underwent engraftment, bacteremia, cytomegalovirus viremia, and invasive aspergillosis were significantly more common in recipients of allogeneic BMTs than in recipients of autologous BMTs. Deaths caused by infection were uncommon and were mainly the result of invasive aspergillosis. Therefore, empirical antimicrobial therapy should be the same for recipients of both allogeneic and autologous BMTs during the period of neutropenia; after engraftment, more attention should be paid to the risk of infection in allogeneic BMT recipients, particularly with regard to detection and prevention of invasive aspergillosis.

Phosphatidylserine delivery to endoplasmic reticulum-derived vesicles of plant cells depends on two biosynthetic pathways

Vesicles formed from endoplasmic reticulum (ER) by a cell-free system of leek cells (Allium porrum) are enriched in phosphatidylserine (PS), especially species containing very long chain fatty acids (VLCFA, at least 20 carbon atoms). In plant cells, PS is formed either by PS synthase or the serine exchange enzyme, although it is not known which pathway(s) contribute(s) to PS delivery in the ER-derived vesicles (EV), nor to what extent this occurs. Taking advantage of a cell-free system, we have shown that PS enrichment originates mainly from the serine exchange enzyme which is the only pathway that synthesizes the VLCFA-PS species. On the other hand, both enzymes synthesize PS with long chain fatty acids (up to 18 carbon atoms), but these species are given to the EV by PS synthase.

Chromosome 13 abnormalities identified by FISH analysis and serum beta2-microglobulin produce a powerful myeloma staging system for patients receiving high-dose therapy

A careful prognostic evaluation of patients referred for high-dose therapy (HDT) is warranted to identify those who maximally benefit from HDT as well as those who clearly fail current HDT and are candidates for more innovative treatments. In a series of 110 patients with myeloma who received HDT as first-line therapy, times to event (disease progression and death) were studied through proportional hazard models, in relation to different prognostic factors, including a chromosome 13 fluorescence in situ hybridization (FISH) analysis using a D13S319 probe. Delta13 was detected in 42 patients (38%). Follow-up time among surviving patients and survival time were 48 +/- 3 and 51 +/- 7 months, respectively (median +/- SE). In the univariate analysis, Delta13 was the most powerful adverse prognostic factor for all times to event, especially for the survival time (P <.0001) and was followed by beta2-microglobulin (beta2m) levels 2.5 mg/L or higher (P =.0001). The comparison of survival prognostic models including beta2m 2.5 mg/L or greater and another factor favored the Delta13/beta2m combination. In 22 patients (20%) with no unfavorable factor, the median survival time was not reached at 111 months. In contrast, among 55 patients (50%) with one unfavorable factor and 33 patients (30%) with 2 unfavorable factors, median survival times were 47.3 +/- 4.6 months and 25.3 +/- 3.2 months, respectively (P <.0001). We conclude that delta13, adequately detected by FISH analysis, is a very strong factor related to poor survival, especially when associated with a beta2m level of 2.5 mg/L or higher. Routine FISH Delta13 assessment is strongly recommended for patients considered for HDT.

A specific interferon (IFN)-stimulated response element of the distal HLA-G promoter binds IFN-regulatory factor 1 and mediates enhancement of this nonclassical class I gene by IFN-beta

Type I interferons display a broad range of immunomodulatory functions. Interferon beta increases gene expression at the transcriptional level through binding of factors to the interferon-stimulated response element (ISRE) within the promoters of interferon-inducible genes, such as HLA class I. Despite mutation of the class I ISRE sequence within the nonclassical HLA-G class I gene promoter, we show that interferon beta enhances both transcription and cell surface expression of HLA-G in trophoblasts and amniotic and thymic epithelial cells that selectively express it in vivo. Deletion and mutagenesis analysis of a putative interferon-regulatory factor (IRF)-1 binding site within the HLA-G promoter show that HLA-G transactivation is mediated through an ISRE sequence 746 base pairs upstream from ATG, which is distinct from the interferon-responsive element described within proximal classical class I gene promoters. Electrophoretic mobility shift analysis and supershift analysis further demonstrate that interferon-responsive transcription factors, including IRF-1, specifically bind to the HLA-G ISRE. Our results provide evidence that IRF-1 binding to a functional ISRE within the HLA-G promoter mediates interferon beta-induced expression of the HLA-G gene. These observations are of general interest considering the implication of HLA-G in mechanisms of immune escape involved in fetal-maternal tolerance and other immune privilege situations.

EES in rare benign tumors

Endoscopic Endonasal Surgery (EES) can successfully be carried out for benign tumors such as osteomas, benign vascular tumors, pituitary adenomas, pneumoceles and benign fibrous tumors. This report concerns a Belgian perspective documenting our experience in 49 such cases. Among them are 33 cases of pituitary adenoma. Thanks to the experience accumulated in the surgical management of inflammatory sinusal disease, these tumors were able to be removed, totally or partially, under endoscopic guidance with the aid of powered endoscopic instrumentation, and in some cases, CO2 laser fiber. Advantages are well-known; lower cost, shorter stay in hospital, lower morbidity, lower cosmetic or functional disabilities. We emphasize the need for the surgeon to be able to switch the endoscopic procedure to an external one if difficulties occur or the tumor is more extensive than expected.

Pelvic limb-salvage surgery for malignant tumors

Thirteen patients with primary malignant tumors of the pelvis underwent internal hemipelvectomy. The diagnoses were: Ewing's sarcoma 7, osteosarcoma 4, chondrosarcoma 1, and malignant fibrous histiocytoma 1. No megaprostheses or massive allografts were used for reconstruction. Six patients underwent resection only with no reconstruction, 5 had strut grafts inserted to restore the pelvic ring, 1 had an autoclaved autograft of the acetabulum and 1 had an ilio-femoral arthrodesis. No patients were lost to follow-up. Nine patients died from their disease after an average of 23 months (range 2 to 72 months). The 4 survivors (3 free of disease) have an average follow-up of 84 months (range 60 to 120 months).

Workshop: excess growth and apoptosis: is hypertension a case of accelerated aging of cardiovascular cells?

Several groups including ours have demonstrated cardiac hyperplasia in neonates from genetically hypertensive rat strains. We have shown that similar problems exist in the kidney as well. More recently, we found that excessive heart and kidney weight is neonatally related to inhibition of apoptosis. Using recombinant inbred strains derived from a reciprocal cross between Brown Norway and spontaneously hypertensive rat progenitor strains, we mapped the inhibition of neonatal apoptosis to 2 distinct loci on chromosomes 1 (Myl 2) and 18 (Abrb 2). Positional candidate genes at these loci are being explored. These studies have also demonstrated that the loci determining kidney and heart weights in neonates are distinct from those determining increased organ weight in adults. The impact of blood pressure per se is also divergent because adult kidney weight is negatively correlated whereas heart weight is positively correlated with it. Analyses by extremes of low and high percentiles from fetal life to adulthood identified a single locus determining heart weight at Acaa on chromosome 8 in newborn (P=0.0003) and adult (P=0.016) rats. The Acaa region contains a DNA mismatch repair gene (hMLH1). The kinetics of neonatal growth through adulthood by prelabeling DNA with [(3)H]thymidine in pregnant mares showed that although the growth process is complex and nonlinear in the kidney of hypertensive rats, there is an increased turnover of cells, that is, reduced half-life of DNA. This observation is supported by the presence of shorter telomere fragments in kidneys of spontaneously hypertensive rats. These studies suggest that cardiovascular cells from hypertensive animals are subject to accelerated turnover, potentially leading to their accelerated aging.

Long-term complications of total body irradiation in adults

PURPOSE

To report long-term pulmonary, thyroid, and ocular complications in patients who had conditioning regimens including total body irradiation (TBI) before bone marrow transplantation (BMT).

METHODS AND MATERIALS

Between June 1986 and December 1995, 478 patients received TBI in our institution. The present study includes 186 adult patients who had complete remission lasting one year or more after BMT. There were 108 males and 78 females. Median age was 36.5 years (range 15-60). Initial diagnoses were lymphomas (50%), acute lymphoid leukemias (16%), acute myeloid leukemias (16%), chronic myeloid leukemia (13%), aplastic anemia (3%), and myelodysplasia (2%). At the time of BMT, 43.5% of patients were in complete response and 56.5% in partial response. Treatment consisted of a single dose TBI at 10 Gy in 9% and fractionated TBI delivering 12 to 13.5 Gy in 6 fractions in 91%. From 1986 to October 1991, TBI was performed in lateral position with 9 MV energy (57% of patients) and thereafter in alternate prone and supine positions with 15 MV energy (43%). Chemical conditioning regimen was cyclophosphamide (60 mg/kg at D-4 and D-3) in 69% and CBV (cyclophosphamide 1500 mg/m(2) from D-6 to D-3, BCNU 300 mg/m(2) at D-6, VP-16 200 mg/m(2) from D-6 to D-4) in 25%. Fifty eight percent of patients received autologous and 42% allogeneic BMT. All patients had clinical, biologic, and functional examinations at one-year intervals.

RESULTS

Median follow-up from BMT was 49 months (range 12-136). Late pulmonary effects were observed only in functional explorations, without clinical effect, including restrictive syndrome in 8% and alteration in the diffusing capacity of carbon monoxide in 12%. No patient showed clinical thyroid symptoms, and 10% developed biologic dysfunction: hypothyroidism (6.5%), thyroiditis (3%), and Basedow disease (0.5%). Ocular complications occurred in 29.5%, including cataract (15%), dry syndrome (13%), and keratitis (1.5%). In univariate and multivariate analysis, pulmonary complications were statistically increased by chronicle graft vs. host disease (GVHD) vs. no (p = 0.02), prone and supine vs. lateral TBI position (p = 0.02), and with 15 MV vs. 9 MV beam energy (p = 0.02). Cataract occurred less frequently with fractionated than with single-dose TBI (p = 0.000002). No differences were observed regarding age, sex, initial diagnosis, status at the time of BMT, conditioning chemotherapy regimen, and total dose of TBI.

CONCLUSION

From this retrospective study it was shown that long-term complications of TBI were not symptomatic in most patients. The role of parameters of irradiation and especially position of treatment and beam energy should be emphasized and assessed with a longer follow-up.