Familial renal cell carcinoma (RCC) is genetically heterogeneous and may be caused by mutations in multiple genes, including VHL, MET, SDHB, FH, FLCN, PTEN, and BAP1. However, most individuals with ...inherited RCC do not have a detectable germline mutation. To identify novel inherited RCC genes, we undertook exome resequencing studies in a familial RCC kindred and identified a CDKN2B nonsense mutation that segregated with familial RCC status. Targeted resequencing of CDKN2B in individuals (n = 82) with features of inherited RCC then revealed three candidate CDKN2B missense mutations (p.Pro40Thr, p.Ala23Glu, and p.Asp86Asn). In silico analysis of the three-dimensional structures indicated that each missense substitution was likely pathogenic through reduced stability of the mutant or reduced affinity for cyclin-dependent kinases 4 and 6, and in vitro studies demonstrated that each of the mutations impaired CDKN2B-induced suppression of proliferation in an RCC cell line. These findings identify germline CDKN2B mutations as a novel cause of familial RCC.
Germline loss-of-function CDKN2B mutations were identified in a subset of patients with features of inherited RCC. Detection of germline CDKN2B mutations will have an impact on familial cancer screening and might prove to influence the management of disseminated disease.
Perlman syndrome is a congenital overgrowth syndrome inherited in an autosomal recessive manner that is associated with Wilms tumor susceptibility. We mapped a previously unknown susceptibility locus ...to 2q37.1 and identified germline mutations in DIS3L2, a homolog of the Schizosaccharomyces pombe dis3 gene, in individuals with Perlman syndrome. Yeast dis3 mutant strains have mitotic abnormalities. Yeast Dis3 and its human homologs, DIS3 and DIS3L1, have exoribonuclease activity and bind to the core RNA exosome complex. DIS3L2 has a different intracellular localization and lacks the PIN domain found in DIS3 and DIS3L1; nevertheless, we show that DIS3L2 has exonuclease activity. DIS3L2 inactivation was associated with mitotic abnormalities and altered expression of mitotic checkpoint proteins. DIS3L2 overexpression suppressed the growth of human cancer cell lines, and knockdown enhanced the growth of these cells. We also detected evidence of DIS3L2 mutations in sporadic Wilms tumor. These observations suggest that DIS3L2 has a critical role in RNA metabolism and is essential for the regulation of cell growth and division.
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DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Familial medullary thyroid cancer (MTC) and its precursor, C cell hyperplasia (CCH), is associated with germline RET mutations causing multiple endocrine neoplasia type 2. However, some rare families ...with apparent MTC/CCH predisposition do not have a detectable RET mutation. To identify novel MTC/CCH predisposition genes we undertook exome resequencing studies in a family with apparent predisposition to MTC/CCH and no identifiable RET mutation. We identified a novel ESR2 frameshift mutation, c.948delT, which segregated with histological diagnosis following thyroid surgery in family members and demonstrated loss of ESR2-encoded ERβ expression in the MTC tumour. ERα and ERβ form heterodimers binding DNA at specific oestrogen-responsive elements (EREs) to regulate gene transcription. ERβ represses ERα-mediated activation of the ERE and the RET promoter contains three EREs. In vitro, we showed that ESR2 c.948delT results in unopposed ERα mediated increased cellular proliferation, activation of the ERE and increased RET expression. In vivo, immunostaining of CCH and MTC using an anti-RET antibody demonstrated increased RET expression. Together these findings identify germline ESR2 mutation as a novel cause of familial MTC/CCH and provide important insights into a novel mechanism causing increased RET expression in tumourigenesis.
ABSTRACT
Investigation of rare familial forms of renal cell carcinoma (RCC) has led to the identification of genes such as VHL and MET that are also implicated in the pathogenesis of sporadic RCC. In ...order to identify a novel candidate renal tumor suppressor gene, we characterized the breakpoints of a constitutional balanced translocation, t(5;19)(p15.3;q12), associated with familial RCC and found that a previously uncharacterized gene UBE2QL1 was disrupted by the chromosome 5 breakpoint. UBE2QL1 mRNA expression was downregulated in 78.6% of sporadic RCC and, although no intragenic mutations were detected, gene deletions and promoter region hypermethylation were detected in 17.3% and 20.3%, respectively, of sporadic RCC. Reexpression of UBE2QL1 in a deficient RCC cell line suppressed anchorage‐independent growth. UBE2QL1 shows homology to the E2 class of ubiquitin conjugating enzymes and we found that (1) UBE2QL1 possesses an active‐site cysteine (C88) that is monoubiquitinated in vivo, and (2) UBE2QL1 interacts with FBXW7 (an F box protein providing substrate recognition to the SCF E3 ubiquitin ligase) and facilitates the degradation of the known FBXW7 targets, CCNE1 and mTOR. These findings suggest UBE2QL1 as a novel candidate renal tumor suppressor gene.
(A) Sanger sequencing of der(5) and der(19) breakpoints of a renal tumour associated constitutional translocation shows the chromosome 5 breakpoint to disrupt a previously uncharacterised gene, UBE2QL1. (B) UBE2QL1 shows homology to the ubiquitin conjugating enzyme family and an in silico search revealed a possible FBXW7 binding domain. We show that UBE2QL1 does bind both ubiquitin and FBXW7. (C) UBE2QL1 shows growth suppression (left) and inhibition of anchorage independent growth (middle), which is dependent upon the active‐site cysteine residue (right).
Luigi Bartalena (luigi.bartalena@uninsubria.it) Endocrine Unit, University of Insubria, Varese, Italy Graves' orbitopathy (GO) is the main extrathyroidal manifestation of Graves' disease. When fully ...expressed, it is characterized by inflammatory soft tissue changes, exophthalmos, ocular dysmotility causing diplopia, and, rarely, sight-threatening dysthyroid optic neuropathy (DON). The prevalence of GO among Graves' patients seems lately declining, probably due to early diagnosis, early intervention on risk factors associated with its occurrence or progression (smoking, uncontrolled thyroid dysfunction), early correction of hyper and hypothyroidism. Only about 25-30% of newly diagnosed Graves' hyperthyroids are affected with GO, which is usually mild and rarely progressive. Assessment of activity and severity of GO according to standardized criteria is fundamental to plan management. The European Thyroid Association and the European Group on Graves' Orbitopathy (EUGOGO) have recently published the first guideline on management of GO. Mild GO usually requires only a watchful strategy, in addition to local measures (eye drops, ointments) and removal of risk factors. Intravenous glucocorticoids (ivGCs) are the first-line treatment for moderate-to-severe and active GO, as demonstrated by randomized clinical trials. When ivGCs fail or GO recurs after treatment withdrawal, options include a second course of ivGCs, oral GCs combined with orbital radiotherapy or cyclosporine, rituximab. Evidence that the any of the above treatment be effective in the context of a poor response to a first course of ivGCs is limited and should be investigated in larger studies. In addition to rituximab, ongoing investigations are exploring the role of other biologics targeting, e.g., the IGF-1 receptor or the IL-6 receptor, and results will probably available in 1-2 years. When GO has been treated medically and is inactive, rehabilitative surgery (orbital decompression, squint surgery, eyelid surgery) is often needed.
Population approaches to lessen the adverse impacts of preschool language delay remain elusive. We aimed to determine whether systematic ascertainment of language delay at age 4 years, followed by a ...10-month, 1-on-1 intervention, improves language and related outcomes at age 5 years.
A randomized trial nested within a cross-sectional ascertainment of language delay. Children with expressive and/or receptive language scores more than 1.25 SD below the mean at age 4 years entered the trial. Children randomly allocated to the intervention received 18 1-hour home-based therapy sessions. The primary outcomes were receptive and expressive language (Clinical Evaluation of Language Fundamentals - Preschool, 2(nd) Edition) and secondary outcomes were child phonological skills, letter awareness, pragmatic skills, behavior, and quality of life.
A total of 1464 children were assessed for language delay at age 4 years. Of 266 eligible children, 200 (13.6%) entered the trial, with 91 intervention (92% of 99) and 88 control (87% of 101) children retained at age 5 years. At age 5 years, there was weak evidence of benefit to expressive (adjusted mean difference, intervention - control, 2.0; 95% confidence interval CI -0.5 to 4.4; P = .12) but not receptive (0.6; 95% CI -2.5 to 3.8; P = .69) language. The intervention improved phonological awareness skills (5.0; 95% CI 2.2 to 7.8; P < .001) and letter knowledge (2.4; 95% CI 0.3 to 4.5; P = .03), but not other secondary outcomes.
A standardized yet flexible 18-session language intervention was successfully delivered by non-specialist staff, found to be acceptable and feasible, and has the potential to improve long-term consequences of early language delay within a public health framework.
We have previously shown short-term benefits to phonology, letter knowledge, and possibly expressive language from systematically ascertaining language delay at age 4 years followed by the Language ...for Learning intervention. Here, we report the trial's definitive 6-year outcomes.
Randomized trial nested in a population-based ascertainment. Children with language scores >1.25 SD below the mean at age 4 were randomized, with intervention children receiving 18 1-hour home-based therapy sessions. Primary outcome was receptive/expressive language. Secondary outcomes were phonological, receptive vocabulary, literacy, and narrative skills; parent-reported pragmatic language, behavior, and health-related quality of life; costs of intervention; and health service use. For intention-to-treat analyses, trial arms were compared using linear regression models.
Of 1464 children assessed at age 4, 266 were eligible and 200 randomized; 90% and 82% of intervention and control children were retained respectively. By age 6, mean language scores had normalized, but there was little evidence of a treatment effect for receptive (adjusted mean difference 2.3; 95% confidence interval CI -1.2 to 5.7; P = .20) or expressive (0.8; 95% CI -1.6 to 3.2; P = .49) language. Of the secondary outcomes, only phonological awareness skills (effect size 0.36; 95% CI 0.08-0.65; P = .01) showed benefit. Costs were higher for intervention families (mean difference AU$4276; 95% CI: $3424 to $5128).
Population-based intervention targeting 4-year-old language delay was feasible but did not have lasting impacts on language, possibly reflecting resolution in both groups. Long-term literacy benefits remain possible but must be weighed against its cost.
Early language delay is a high-prevalence condition of concern to parents and professionals. It may result in lifelong deficits not only in language function, but also in social, ...emotional/behavioural, academic and economic well-being. Such delays can lead to considerable costs to the individual, the family and to society more widely. The Language for Learning trial tests a population-based intervention in 4 year olds with measured language delay, to determine (1) if it improves language and associated outcomes at ages 5 and 6 years and (2) its cost-effectiveness for families and the health care system.
A large-scale randomised trial of a year-long intervention targeting preschoolers with language delay, nested within a well-documented, prospective, population-based cohort of 1464 children in Melbourne, Australia. All children received a 1.25-1.5 hour formal language assessment at their 4th birthday. The 200 children with expressive and/or receptive language scores more than 1.25 standard deviations below the mean were randomised into intervention or 'usual care' control arms. The 20-session intervention program comprises 18 one-hour home-based therapeutic sessions in three 6-week blocks, an outcome assessment, and a final feed-back/forward planning session. The therapy utilises a 'step up-step down' therapeutic approach depending on the child's language profile, severity and progress, with standardised, manualised activities covering the four language development domains of: vocabulary and grammar; narrative skills; comprehension monitoring; and phonological awareness/pre-literacy skills. Blinded follow-up assessments at ages 5 and 6 years measure the primary outcome of receptive and expressive language, and secondary outcomes of vocabulary, narrative, and phonological skills.
A key strength of this robust study is the implementation of a therapeutic framework that provides a standardised yet tailored approach for each child, with a focus on specific language domains known to be associated with later language and literacy. The trial responds to identified evidence gaps, has outcomes of direct relevance to families and the community, includes a well-developed economic analysis, and has the potential to improve long-term consequences of early language delay within a public health framework.
Current Controlled Trials ISRCTN03981121.
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