Denosumab for craniofacial fibrous dysplasia: duration of efficacy and post-treatment effects.

Denosumab has been advocated as a potential treatment for the rare skeletal disorder fibrous dysplasia (FD); however, there is limited data to support safety and efficacy, particularly after drug discontinuation. We report a case of successful treatment of aggressive craniofacial FD with denosumab, highlighting novel insights into the duration of efficacy, surrogate treatment markers, and discontinuation effects. A 13-year-old girl presented with persistent pain and expansion of a maxillary FD lesion, which was not responsive to repeated surgical procedures or bisphosphonates. Pre-treatment biopsy showed high RANKL expression and localization with proliferation markers. Denosumab therapy was associated with improved pain, decreased bone turnover markers, and increased lesion density on computed tomography scan. During 3.5 years of treatment, the patient developed increased non-lesional bone density, and after denosumab discontinuation, she developed hypercalcemia managed with bisphosphonates. Pain relief and lesion stability continued for 2 years following treatment, and symptom recurrence coincided with increased bone turnover markers and decreased lesion density back to pre-treatment levels. This case highlights the importance of considering the duration of efficacy when treating patients with FD and other nonresectable skeletal neoplasms that require long-term management.

Balanced Steady-State Free Precession Sequence (CISS/FIESTA/3D Driven Equilibrium Radiofrequency Reset Pulse) Increases the Diagnostic Yield for Spinal Drop Metastases in Children with Brain Tumors.

BACKGROUND AND PURPOSE: Identification of spinal drop metastases is important in the staging and management of pediatric patients with primary brain tumors. Our aim was to assess the diagnostic utility of the balanced steady-state free precession (bSSFP) sequence (CISS/FIESTA/3D driven equilibrium radiofrequency reset pulse) for the detection of spinal drop metastases in pediatric patients with primary intracranial tumors. MATERIALS AND METHODS: This was a retrospective study of 44 pediatric patients with primary intracranial tumors undergoing MR imaging spine evaluation for drop metastases before radiation treatment. All patients underwent a whole-spine MRI with both bSSFP and postcontrast T1WI sequences. Two neuroradiologists independently reviewed only the bSSFP sequence, then 1 week later only the postcontrast T1WI sequence. RESULTS: Patients ranged from 1 to 18 years of age (mean, 7.1 ± 4.2 years) with 27 males and 17 females. The number of lesions per patient ranged from 1 to 13 and from 2 to 11 mm in size. Lesions suspicious for drop metastases were seen in 8 patients on the postcontrast T1WI (18%) compared with 10 patients on the bSSFP sequence (23%). Twenty-two drop metastases seen on the bSSFP sequence were not visible on the postcontrast T1WI, including nonenhancing drop metastases and multiple nodules of <3 mm. Interrater agreement was excellent for the bSSFP sequence (0.91) and the postcontrast T1 sequence (0.90). CONCLUSIONS: The bSSFP sequence increased the diagnostic yield for the detection of drop metastases in pediatric patients with primary intracranial tumors and was particularly advantageous for small drop metastases (<3 mm) and nonenhancing metastases, and it decreased the number of false-positives. The bSSFP sequence may be an important adjunct to postcontrast T1WI for the evaluation of drop metastases.

Antiangiogenic therapy of a recurrent giant cell tumor of the mandible with interferon alfa-2a.

We report a 5-year-old girl with a large rapidly growing giant cell tumor of the mandible that recurred 2 months after the first surgical excision and 3 months after a second resection. An angiogenic protein, (bFGF), was abnormally elevated in her urine. The patient was treated with interferon alfa-2a for 1 year because this agent inhibits angiogenesis by suppressing bFGF overexpression in infantile hemangiomas and in other human tumors. During this time the bone tumor regressed and disappeared, the urinary bFGF fell to normal levels, and the mandible regenerated. She has remained tumor-free and has been off therapy for 3 years at this writing. This first successful use of interferon alfa-2a to treat a mandibular tumor in a child demonstrates: 1) low grade tumors that overexpress bFGF may respond to interferon alfa-2a, in a manner similar to life-threatening infantile hemangiomas; 2) antiangiogenic therapy, given without interruption for 1 year, was safe and effective in this patient; and 3) treatment may be continued for 1 year without the development of drug resistance.

Identification of upstream regulatory elements that repress expression of adult beta-like globin genes in a primitive erythroid environment.

Our investigations have focused on localizing cis-elements responsible for the down regulation of the adult beta-like globin genes (delta and beta) in immature, or primitive erythroid tissues. We studied their activity after transfection into K562 cells, an erythroleukemia cell line with an embryonic-fetal phenotype. Analyzed DNA sequences included delta and beta 5' flanking regions extending from approximately -500 to +50bp (promoter regions), truncated delta and beta 5' flanking regions extending from approximately -250 to +50 bp, and chimeric promoter constructions, which consisted of a distal delta or beta fragment fused to a proximal beta or delta sequence. In CAT reporter constructions no appreciable level of CAT activity was supported by the beta globin promoter, and only low level activity by the delta promoter. Truncation of the beta globin promoter led to a 2-3 fold increase in promoter activity. In contrast, deletion of the upstream portion of the delta promoter led to a 10 fold decrease in expression. Coupling of the upstream beta globin sequence from approximately -500 to -250 bp to the truncated delta promoter fragment led to complete extinction of transcription activity, consistent with a negative regulatory effect of the beta globin gene upstream element(s). Fusion of the upstream portion of the delta promoter to the truncated beta globin promoter yielded a modest increase in promoter strength relative to the truncated beta gene promoter, indicating the presence of a positive transcriptional element(s) in the upstream delta globin regulatory region. Site-directed mutagenesis of binding sites for the repressor proteins BP1 and BP2 in the upstream portion of the beta globin gene flanking region led to a 4-6 fold increase in promoter activity. DNase I footprinting of the upstream delta-globin region revealed protected sequences corresponding to consensus binding sites for GATA-1 and BP2. These results confirm that sequences in the upstream promoter region of the adult beta globin gene contribute to its factor-mediated suppression early in development and then may modulate its expression at a later stage.

Diagnosis and treatment of childhood acute myelogenous leukemia.

Acute myelogenous leukemia (AML) accounts for about 20% of the acute leukemias seen in children. In contrast to childhood acute lymphoblastic leukemia (ALL), there has only been a modest improvement in the cure rate of children with AML during the past two decades. Approximately 40% of children treated with chemotherapy alone are long-term survivors. The outcome is somewhat better for those children who are given bone marrow transplants from histocompatible sibling donors early in the first remission. During the last decade, however, new insights into the molecular basis of AML has increased our understanding of the pathogenesis and biology of this group of leukemias and are beginning to provide us with new therapeutic strategies.

Restoration of the CCAAT box or insertion of the CACCC motif activates [corrected] delta-globin gene expression.

Hemoglobin A2 (HbA2), which contains delta-globin as its non-alpha-globin, represents a minor fraction of the Hb found in normal adults. It has been shown recently that HbA2 is as potent as HbF in inhibiting intracellular deoxy-HbS polymerization, and its expression is therefore relevant to sickle cell disease treatment strategies. To elucidate the mechanisms responsible for the low-level expression of the delta-globin gene in adult erythroid cells, we first compared promoter sequences and found that the delta-globin gene differs from the beta-globin gene in the absence of an erythroid Krüppel-like factor (EKLF) binding site, the alteration of the CCAAT box to CCAAC, and the presence of a GATA-1 binding site. Second, serial deletions of the human delta-globin promoter sequence fused to a luciferase (LUC) reporter gene were transfected into K562 cells. We identified both positive and negative regulatory regions in the 5' flanking sequence. Furthermore, a plasmid containing a single base pair (bp) mutation in the CCAAC box of the delta promoter, restoring the CCAAT box, caused a 5.6-fold and 2.4-fold (P < .05) increase of LUC activity in transfected K562 cells and MEL cells, respectively, in comparison to the wild-type delta promoter. A set of substitutions that create an EKLF binding site centered at -85 bp increased the expression by 26.8-fold and 6.5-fold (P < .05) in K562 and MEL cells, respectively. These results clearly demonstrate that the restoration of either an EKLF binding site or the CCAAT box can increase delta-globin gene expression, with potential future clinical benefit.

Spinal cord compression in widely metastatic Wilms' tumor. Paraplegia in two children with anaplastic Wilms' tumor.

Spinal cord compression in Wilms' tumor is a rare event, generally caused by invasion of the canal by paraspinal lesions or metastatically involved vertebral bodies. This case report reviews the clinical presentation, radiologic evaluation, and emergent therapy in two cases of spinal cord compromise involving patients with widely metastatic Wilms' tumor. One of these is the only known report of intradural metastasis in a child with this malignancy. Both cases illustrate the importance of anticipating and rapidly responding to neurologic complications that may arise in patients with aggressively metastatic Wilms' tumor.