Hereditary hemorrhagic telangiectasia (HHT) is an inherited disorder characterized by vascular malformations. Many affected individuals develop recurrent nosebleeds, which can severely affect their quality of life and are clinically difficult to treat. We report here that treatment with thalidomide reduced the severity and frequency of nosebleeds (epistaxis) in the majority of a small group of subjects with HHT tested. The blood hemoglobin levels of the treated individuals rose as a result of reduced hemorrhage and enhanced blood vessel stabilization. In mice heterozygous for a null mutation in the Eng gene (encoding endoglin), an experimental model of HHT, thalidomide treatment stimulated mural cell coverage and thus rescued vessel wall defects. Thalidomide treatment increased platelet-derived growth factor-B (PDGF-B) expression in endothelial cells and stimulated mural cell activation. The effects of thalidomide treatment were partially reversed by pharmacological or genetic interference with PDGF signaling from endothelial cells to pericytes. Biopsies of nasal epithelium from individuals with HHT treated or not with thalidomide showed that similar mechanisms may explain the effects of thalidomide treatment in humans. Our findings demonstrate the ability of thalidomide to induce vessel maturation, which may be useful as a therapeutic strategy for the treatment of vascular malformations.
To investigate the role of the Fhit gene in carcinogen induction of neoplasia, we have inactivated one Fhit allele in mouse embryonic stem cells and produced (129͞SvJ ؋ C57BL͞6J) F1 mice with a Fhit allele inactivated (؉͞؊). Fhit ؉͞؉ and ؉͞؊ mice were treated intragastrically with nitrosomethylbenzylamine and observed for 10 wk posttreatment. A total of 25% of the ؉͞؉ mice developed adenoma or papilloma of the forestomach, whereas 100% of the ؉͞؊ mice developed multiple tumors that were a mixture of adenomas, squamous papillomas, invasive carcinomas of the forestomach, as well as tumors of sebaceous glands. The visceral and sebaceous tumors, which lacked Fhit protein, were similar to those characteristic of Muir-Torre familial cancer syndrome.esophageal͞gastric cancer ͉ N-nitrosomethylbenzylamine ͉ carcinogeninduced tumorigenesis ͉ Fhit knockout mice ͉ tumor suppressor gene
Purpose In low–tumor burden follicular lymphoma (FL), maintenance rituximab (MR) has been shown to improve progression-free survival when compared with observation. It is not known whether MR provides superior long-term disease control compared with re-treatment rituximab (RR) administered on an as-needed basis. E4402 (RESORT) was a randomized clinical trial designed to compare MR against RR. Patients and Methods Eligible patients with previously untreated low–tumor burden FL received four doses of rituximab, and responding patients were randomly assigned to either RR or MR. Patients receiving RR were eligible for re-treatment at each disease progression until treatment failure. Patients assigned to MR received a single dose of rituximab every 3 months until treatment failure. The primary end point was time to treatment failure. Secondary end points included time to first cytotoxic therapy, toxicity, and health-related quality of life (HRQOL). Results A total of 289 patients were randomly assigned to RR or MR. With a median follow-up of 4.5 years, the estimated median time to treatment failure was 3.9 years for patients receiving RR and 4.3 years for those receiving MR (P = .54). Three-year freedom from cytotoxic therapy was 84% for those receiving RR and 95% for those receiving MR (P = .03). The median number of rituximab doses was four patients receiving RR and 18 for those receiving MR. There was no difference in HRQOL. Grade 3 to 4 toxicities were infrequent in both arms. Conclusion In low–tumor burden FL, a re-treatment strategy uses less rituximab while providing disease control comparable to that achieved with a maintenance strategy.
BackgroundA phase II trial of dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin and rituximab (DA-EPOCH-R) from the National Cancer Institute showed promising activity in untreated diffuse large B-cell lymphoma. The Cancer and Leukemia Group B conducted a study to determine if these results could be reproduced in a multi-institutional setting. Design and MethodsThe study included 69 patients with untreated diffuse large B-cell lymphoma at least 18 years of age and at least stage II. Radiaton therapy was not permitted on study. Median age was 58 years (range 23-83) and 40% had high-intermediate or high International Prognostic Index risk. Immunohistochemical biomarkers for cell of origin and proliferation were performed. ResultsWith a median follow up of 62 months, time to progression and overall survival were 81% and 84%, respectively, and time to progression was 87%, 92% and 54% for low/low-intermediate, high-intermediate and high International Prognostic Index risk groups, respectively, at 5-years and beyond. The time to progression and event-free survival of germinal center B-cell lymphoma were 100% and 94%, respectively, and non-germinal center B-cell GCB diffuse large Bcell lymphoma were 67% and 58%, respectively, at 62 months (germinal center vs. non-germinal center B cell P=0.008). DA-EPOCH-R was tolerated without significant grade 4 non-hematologic toxicities. ConclusionsThese results provide the first confirmation by a multi-institutional group that DA-EPOCH-R provides high durable remissions in diffuse large B-cell lymphoma and is effective in both germinal center and non-germinal center B-cell subtypes. The trial was registered at ClinicalTrials.Gov (NCT00032019).Key words: diffuse large B-cell lymphoma, DA-EPOCH-rituximab, untreated, outome, molecular. subtype. Haematologica 2012;97(5):758-765. doi:10.3324/haematol.2011 This is an open-access paper. Citation: Wilson WH, Jung S-H, Porcu P, Hurd D, Johnson J, Martin SE, Czuczman M, Lai R, Said J, Chadburn A, Jones D, Dunleavy K, Canellos G, Zelenetz AD, Cheson BD, and Hsi ED for the Cancer and Leukemia Group B. A Cancer and Leukemia Group B multi-center study of DA-EPOCH-rituximab in untreated diffuse large B-cell lymphoma with analysis of outcome by molecular A Cancer and Leukemia Group B multi-center study of DA-EPOCH-rituximab
Fine-mapping of trait loci through combined linkage and association analysis is an important component of strategies designed to identify causative gene variants, particularly in situations where the trait may be influenced by one or more of many polymorphisms within the same gene. Angiotensin-1 converting enzyme (ACE) provides one of the best models for developing and testing such methodologies, as a major fraction of the heritable variation in the activity of the angiotensin-1 converting enzyme (ACE) is tightly linked to the ACE gene. Moreover, ACE contains many frequent polymorphisms that are in strong linkage disequilibrium with each other. Although none of these variants induces a significant amino-acid change, one or more, either singly or in combination, are likely to have a strong effect on the quantitative phenotype. Here, we show that measured-haplotype analysis of SNP data from a large European family cohort can be used to localise the major ACE-linked genetic factors influencing the trait to a 16 kb interval within the gene, thus limiting the number of ACE variants that need to be considered in future studies designed to elucidate their biological effects. The approaches developed will be applicable to the fine-mapping of other quantitative trait loci in humans.
Circulating angiotensin-1-converting enzyme (ACE) is a highly heritable trait, and a major component of the genetic variance maps to the region of the ACE gene. The strong effect of the locus, and the interest in ACE as a candidate gene for cardiovascular disorders, has led to extensive investigation of its relationship to the ACE phenotype, providing one of the most complete examples of quantitative trait locus (QTL) analysis in humans. Resequencing of ACE followed by haplotype analysis in families of British and French origin has shown that the genetic variants that are primarily associated with the ACE trait map to an 18 kb interval flanked by two intragenic, ancestral recombination breakpoints. This critical interval contains dozens of ACE-associated variants in Caucasians, but identification of which of these directly influence ACE concentration is ambiguous because of the almost complete linkage disequilibrium in European populations. In a complementary sequencing and genotyping study of individuals from West African families, we show that this population has much greater haplotype diversity across the gene. Through analysis of the contrasting relationships of the trait phenotype with haplotypes that carry different allelic combinations from those observed in Caucasians, we demonstrate that (at least) two major intragenic sites within the critical interval and (at least) one minor promoter site are associated with the ACE quantitative trait through additive effects. These results point to the importance of analysing diverse populations with different gene genealogies in gene-association studies.
Background-Angiotensin-converting enzyme (ACE) metabolizes many small peptides and plays a key role in blood pressure regulation. Elevated serum ACE is claimed to be associated with an increased risk for cardiovascular disease. Previously, two families with dramatically increased serum ACE were described, but no systematic survey of affected individuals was performed, and the molecular background of this trait is unknown. Methods and Results-Eight families were identified with autosomal dominant inheritance of a dramatic (5-fold) increase of serum ACE activity. Strikingly, no clinical abnormalities were apparent in the affected subjects. Isolated blood cells were used for genetic and biochemical analysis. The level of ACE expression on the blood leukocytes and dendritic cells and total cell-associated ACE of the affected individuals was similar to that in nonaffected relatives; however membrane-bound mutant ACE was much more efficiently clipped from the cell surface compared with its wild-type counterpart. A point mutation causing Pro1199Leu in the stalk region of the ACE molecule cosegregates with the increase in serum ACE (LOD score, 6.63). Conclusions-A point mutation in the stalk region of the ACE protein causes increased shedding, leading to increased serum ACE, whereas cell-bound ACE is unaltered, and affected individuals exhibit no clinical abnormalities. These findings qualify the importance of serum ACE and establish a new determinant of ACE solubilization. (Circulation.
Frequent allelic loss at human chromosome 11q23-q24 occurs in a wide variety of cancers, suggesting that this region may harbor a tumor suppressor gene. By constructing a physical map of the LOH11CR2 minimal region of loss on 11q23-q24 associated with lung and breast carcinomas, we were able to clone a hereditary translocation, t(11;12)(q23;q24), in a patient with early-onset breast cancer and family history of cancer. The breakpoint was found within 6 kb of the BCSC-1 candidate tumor suppressor gene located in the LOH11CR2 region whereas additional loss of heterozygosity (LOH) analysis in breast and ovarian tumors, including that of the patient with the t(11;12)(q23;q24), implicated the BCSC-1 locus as the primary target of deletion. Northern analysis of the BCSC-1 mRNA revealed a lack of expression in 33 of 41 (80%) tumor cell lines, and its ectopic expression led to the suppression of colony formation in vitro and tumorigenicity in vivo. These data suggest that BCSC-1 may exert a tumor suppressor activity and is a likely target of the LOH observed on 11q23-q24 in cancer.
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