GR-891: a novel 5-fluorouracil acyclonucleoside prodrug for differentiation therapy in rhabdomyosarcoma cells

Differentiation therapy provides an alternative treatment of cancer that overcomes the undesirable effects of classical chemotherapy, i.e. cytotoxicity and resistance to drugs. This new approach to cancer therapy focuses on the development of specific agents designed to selectively engage the process of terminal differentiation, leading to the elimination of tumorigenic cells and recovery of normal cell homeostasis. A series of new anti-cancer pyrimidine acyclonucleoside-like compounds were designed and synthesized by structural modifications of 5-fluorouracil, a drug which causes considerable cell toxicity and morbidity, and we evaluated their applicability for differentiation therapy in human rhabdomyosarcoma cells. We tested the pyrimidine derivative GR-891, (RS)-1-{[3-(2-hydroxyethoxy)-1-isopropoxy]propyl}-5-fluorouracil, an active drug which shows low toxicity in vivo and releases acrolein which is an aldehyde with anti-tumour activity. Both GR-891 and 5-fluorouracil caused time- and dose-dependent growth inhibition in vitro; however, GR-891 showed no cytotoxicity at low doses (22.5 μmol l−1 and 45 μmol l−1) and induced terminal myogenic differentiation in RD cells (a rhabdomyosarcoma cell line) treated for 6 days. Changes in morphological features and in protein organization indicated re-entry in the pathway of muscular maturation. Moreover, GR-891 increased adhesion capability mediated by the expression of fibronectin, and did not induce overexpression of P-glycoprotein, the mdr1 gene product, implicated in multidrug resistance. New acyclonucleoside-like compounds such as GR-891 have important potential advantages over 5-fluorouracil because of their lower toxicity and their ability to induce myogenic differentiation in rhabdomyosarcoma cells. Our results suggest that this drug may be useful for differentiation therapy in this type of tumour. 1999 Cancer Research Campaig

MRI post mortem bij pasgeborenen bij wie obductie niet wordt toegestaan

2 newborns, boys weighing 1400 and 950 g, died 2 and 8 hours after birth respectively. Autopsy was not permitted but MRI was possible. In the first newborn, characteristic abnormalities ofa Potter's sequence were found: pulmonary hypoplasia, missing kidneys and ureters and a rudimentary bladder. Clinically, a small chest, low-positioned ears, a flattened nose, a retracted chin, contractures of both knees and a talipes equinus of both feet had already been observed. In the second newborn, an MRI scan of the skull revealed a torn cerebellar tentorium with intracranial bleeding. The cause of death in newborns is often unknown. Autopsy is the gold standard for determining the cause of death. However for a variety of reasons, many parents do not give informed consent for autopsy. In such cases, post-mortem MRI may be an alternative. Abnormalities ofthe central nervous system, muscles and internal organs can usually be clearly visualized using MRI. However, the diagnosis of cardiac abnormalities using this technique is more difficul

Microsatellite instability in childhood rhabdomyosarcoma is locus specific and correlates with fractional allelic loss.

Replication errors (RERs) were initially identified in hereditary nonpolyposis colon cancer and other tumors of Lynch syndrome II. Mutations in genes involved in mismatch repair give rise to a mutator phenotype, resulting in RERs. The mutator phenotype is thought to predispose to malignant transformation. Here we show that in the embryonal form of childhood rhabdomyosarcoma, RERs also occur, but in contrast to hereditary nonpolyposis colon cancer, only a subset of the microsatellite loci analyzed show RERs. The occurrence of RERs is strongly correlated with increased fractional allelic loss (P < 0.001), suggesting that the occurrence of RERs is a secondary phenomenon in rhabdomyosarcoma. Coincidental loss of genes involved in mismatch repair, possibly due to their proximity to tumor suppressor genes involved in tumor progression of embryonal form of childhood rhabdomyosarcoma, could explain the observed phenomenon

Een meisje met het syndroom van Cushing door primaire gepigmenteerde nodulaire adrenocorticale ziekte

A 12.5-year-old girl with diabetes mellitus type 1 presented with stunted growth and an increase in body weight. Also, her blood-sugar levels were difficult to manage. An adrenocorticotropin-(ACTH)-independent form of Cushing's syndrome was diagnosed. During the dexamethasone-suppression test, a paradoxical increase in urinary-free cortisol excretion was observed, which is a clear indication of primary pigmented nodular adrenocortical disease (PPNAD). The treatment for patients with PPNAD is bilateral adrenalectomy and hormone substitution. PPNAD may be part of the Carney complex, an autosomal dominant multiple neoplasia syndrome. Screening of family members is mandatory. Further investigation for mutations in the gene encoding the regulatory subunit 1A of the protein kinase A (PRKAR1A) may be helpful

Two cases of severe neonatal hypertrophic cardiomyopathy caused by compound heterozygous mutations in the MYBPC3 gene

Background: Idiopathic ( primary) hypertrophic cardiomyopathy (HCM) is mainly caused by mutations in genes encoding sarcomeric proteins. One of the most commonly mutated HCM genes is the myosin binding protein C (MYBPC3) gene. Mutations in this gene lead mainly to truncation of the protein which gives rise to a relatively mild phenotype. Pure HCM in neonates is rare and most of the time childhood HCM occurs in association with another underlying condition. Objective: To study the presence of mutations in the MYBPC3 gene in idiopathic childhood HCM. Methods: MYBPC3 coding region and splice junction variation were analysed by denaturing high performance liquid chromatography (DHPLC) and sequencing in DNA isolated from two neonates with severe unexplained HCM, who died within the first weeks of life. Results: Truncating mutations were found in both alleles of the MYBPC3 gene in both patients, suggesting there was no functional copy of the MYBPC3 protein. Patient 1 carried the maternally inherited c. 2373_2374insG mutation and the paternally inherited splice-donor site mutation c.1624+1G -> A. Patient 2 carried the maternally inherited frameshift mutation c.3288delA (p.Glu1096fsX92) and the paternally inherited non-sense mutation c.2827C -> T (p.Arg943X). Conclusions: The findings indicate the need for mutation analysis of genes encoding sarcomeric proteins in childhood HCM and the possibility of compound heterozygosity