Citations

Abstract MLH3 is a recently described member of the DNA mismatch repair gene family. Based on its interaction with the MutL homologue MLH1, it was postulated that MLH3 might play a role in tumorigenesis. Germ line and somatic mutations in MLH3 have been identified in a small fraction of colorectal cancers, but the role of MLH3 in colorectal cancer tumorigenesis remains controversial. We investigated MLH3's role in endometrial tumorigenesis through analysis of tumor and germ line DNA from 57 endometrial cancer patients who were at increased risk for having inherited cancer susceptibility. Patients with known MSH2 or MSH6 mutations were excluded as well as those who had MLH1-methylated tumors. Sixteen different variants were identified by single-strand conformational variant analysis. Of the 12 missense changes identified, three were somatic mutations. One patient had a germ line missense variant and loss of heterozygosity (LOH) in her tumor specimen. There was no evidence of MLH3 promoter methylation based on combined bisulfite restriction analysis. The identification of inherited missense variants, somatic missense mutations (present in 3 of 57 tumors), and LOH in the tumor from a patient with a germ line missense change suggest a role for MLH3 in endometrial tumorigenesis. (Cancer Res 2006; 66(15): 7502-8)

PurposeTo determine the maximal tolerated dosage (MTD) of oral fenretinide given as intact capsules for 7 days, repeated every 21 days, in children with high-risk solid tumors.MethodsChildren 21 years of age or younger received daily doses from 350 mg/m2to 3,300 mg/m2(divided into two or three doses), with pharmacokinetics during course one. The MTD was defined as zero to one of six patients with dose-limiting toxicity (DLT), with at least two of three or two of six DLT at next higher dose.ResultsFifty-four patients, age 2 years to 20 years (median, 9 years), were treated: neuroblastoma (n = 39), Ewing sarcoma (n = 5), and other (n = 10). Prior therapy included autologous stem cell transplantation (n = 42), 13-cis-RA (n = 35), and 9-cis-RA (n = 1). One of four patients at 1,050 mg/m2with prior liver transplant had grade 3 ALT/abdominal pain/nausea/dehydration and grade 4 AST/emesis. At 1,860 mg/m2, one of seven patients had grade 3 hypoalbuminemia/hypophosphatemia. At 2,475 mg/m2, one of eight patients had grade 3 alkaline phosphatase; three of five patients had DLT at 3,300 mg/m2: grade 3 AST/ALT (n = 1), grade 4 bilirubin/grade 3 AST/ALT (n = 1), pseudotumor cerebri (n = 1). Pseudotumor cerebri also occurred at 600 mg/m2and 800 mg/m2. There was one complete response and 13 patients with stable disease (SD) for 8 or more courses in 30 assessable neuroblastoma patients. SD for 8 or more courses was seen in one of five Ewing sarcoma patients and one melanoma patient. Mean N-4-hydroxyphenyl retinamide plasma level (day 7, steady-state concentration) was 9.9 μmol/L at MTD.ConclusionThe pediatric MTD of oral capsular fenretinide was 2,475 mg/m2per day, which achieved levels active against neuroblastoma in vitro with minimal toxicity. Response data support a phase II trial in neuroblastoma.

There has been much research documenting the impact of having a loved one diagnosed with advanced cancer, but little is known about how to reduce care-giver burden. In this randomized controlled trial, the authors examined the potential relationship of an advanced cancer patient’s participation in an 8-session, structured, multidisciplinary intervention on the care-giver’s burden and quality of life (QOL). Although the patients randomly assigned to the intervention (n = 54) demonstrated improved QOL compared to the control condition (n = 49) participants ( P < .05), there was no evidence that improving the patient’s QOL made an impact on the caregiver’s level of burden or the care-giver’s QOL. Further investigation is warranted in this area, including interventions specifically designed and targeted to both reduce caregiver burden and to improve caregiver QOL.

Abstract We report here the first association between vitamin D–resistant rickets, alopecia, and type 1 diabetes in a child with compound heterozygous mutations in the VDR gene. Transfection studies suggest dissociated effects of VDR gene mutations on the regulation of genes involved in vitamin D metabolism and dendritic cell maturation. Introduction: Whereas vitamin D may play a role in the immune tolerance process, no patient has been reported to associate hereditary vitamin D–resistant rickets (HVDRR) and an autoimmune disease, and no attempt has been made to delineate the outcome of mutations of the vitamin D receptor (VDR) on the transcription of genes controlling immune tolerance. Materials and Methods: The VDR gene was analyzed in a child with vitamin D–resistant rickets, total alopecia, and early childhood–onset type 1 diabetes. Patient's fibroblasts and COS-7 cells transfected with wildtype or mutant VDRs were studied for ligand-binding capacity, transactivation activity using two gene promoters [CYP-24, a classical 1,25(OH)2D3-responsive gene, and relB, a critical NF-κB component for regulation of dendritic cell differentiation], VDR-RXR heterodimers association to CYP 24 VDREs by gel mobility shift assays, and co-activator binding by Glutathione-S-transferase pull-down assays. Results: Two novel compound heterozygous mutations (L263R and R391S) were identified in the VDR ligand-binding domain in this child. Both mutations significantly impaired VDR ligand-binding capacity but had dissociated effects on CYP-24 and RelB promoter responses to vitamin D. CYP 24 response binding to SRC-1 and RXR-heterodimer binding to CYP24 VDREs were abolished in L263R mutants but normal or partially altered in R391S mutants. In the opposite, RelB responses to vitamin D were close to normal in L263R mutants but abolished in R391S mutants. Conclusions: We report the first clinical association between HVDRR, total alopecia, and early childhood–onset type 1 diabetes. Mutations in the VDR ligand-binding domain may hamper the 1,25(OH)2D3–mediated relB responses, an effect that depends on the site of the VDR mutation and cannot be anticipated from VDR ligand-binding ability or CYP-24 response. Based on these results, we propose to survey the immune function in patients with HVDRR, including those with moderate features of rickets.