Screening for pineal trilateral retinoblastoma revisited: a meta-analysis

Topic To determine until what age children are at risk for pineal trilateral retinoblastoma (TRb), whether its onset is linked to the age at which intraocular retinoblastomas develop, and the lead time from a detectable pineal TRb to symptoms. Clinical relevance About 45% of patients with retinoblastoma – those with a germline RB1 pathogenic variant – are at risk for pineal TRb. Early detection and treatment is essential for survival. Current evidence is unclear on the usefulness of screening for pineal TRb and, if useful, until what age screening should be continued. Methods We conducted a study according to the MOOSE guideline for reporting meta-analyses of observational studies. We searched PubMed and Embase between January 1, 1966, and February 27, 2019, for published literature. We considered articles reporting patients with TRb with survival and follow-up data. Inclusion of articles was performed separately and independently by two authors, and two authors also independently extracted the relevant data. They resolved discrepancies by consensus. Results One hundred thirty-eight patients with pineal TRb were included. Of 22 asymptomatic patients, 21 (95%) were diagnosed before the age of 40 months (median 16, interquartile range 9–29). Age at diagnosis of pineal TRb in patients diagnosed with retinoblastoma at ≤6 months versus >6 months of age were comparable (P=0.44), suggesting independency between the ages at diagnosis of intraocular retinoblastoma and pineal TRb. The laterality of intraocular retinoblastoma and its treatment were unassociated with the age when the pineal TRb was diagnosed. The lead time from an asymptomatic to a symptomatic pineal TRb was approximately 1 year. By performing a screening magnetic resonance imaging scan every 6 months after the diagnosis of heritable retinoblastoma (median age 6 months) until the age of 36 months, at least 311 and 776 scans would be required to detect one asymptomatic pineal TRb and to save one life, respectively. Conclusion Patients with retinoblastoma are at risk for pineal trilateral retinoblastoma for a shorter period than previously assumed and the age at diagnosis of pineal trilateral retinoblastoma is independent of the age at diagnosis of retinoblastoma. The GRADE level of evidence for these conclusions remains low.Peer reviewe

Cdh11 Acts as a Tumor Suppressor in a Murine Retinoblastoma Model by Facilitating Tumor Cell Death

CDH11 gene copy number and expression are frequently lost in human retinoblastomas and in retinoblastomas arising in TAg-RB mice. To determine the effect of Cdh11 loss in tumorigenesis, we crossed Cdh11 null mice with TAg-RB mice. Loss of Cdh11 had no gross morphological effect on the developing retina of Cdh11 knockout mice, but led to larger retinal volumes in mice crossed with TAg-RB mice (p = 0.01). Mice null for Cdh11 presented with fewer TAg-positive cells at postnatal day 8 (PND8) (p = 0.01) and had fewer multifocal tumors at PND28 (p = 0.016), compared to mice with normal Cdh11 alleles. However, tumor growth was faster in Cdh11-null mice between PND8 and PND84 (p = 0.003). In tumors of Cdh11-null mice, cell death was decreased 5- to 10-fold (p<0.03 for all markers), while proliferation in vivo remained unaffected (p = 0.121). Activated caspase-3 was significantly decreased and β-catenin expression increased in Cdh11 knockdown experiments in vitro. These data suggest that Cdh11 displays tumor suppressor properties in vivo and in vitro in murine retinoblastoma through promotion of cell death

Asynchronous pineoblastoma is more likely after early diagnosis of retinoblastoma : a meta-analysis

Purpose To determine the risk of patients with an early diagnosis of heritable retinoblastoma being diagnosed with TRb (or pineoblastoma) asynchronously in a later stage and its effect on screening. Methods We updated the search (PubMed and Embase) for published literature as performed by our research group in 2014 and 2019. Trilateral retinoblastoma (TRb) patients were eligible for inclusion if identifiable as unique and the age at which TRb was diagnosed was available. The search yielded 97 new studies. Three new studies and eight new patients were included. Combined with 189 patients from the previous meta-analysis, the database included 197 patients. The main outcome was the percentage of asynchronous TRb in patients diagnosed before and after preset age thresholds of 6 and 12 months of age at retinoblastoma diagnosis. Results Seventy-nine per cent of patients with pineoblastoma are diagnosed with retinoblastoma before the age of 12 months. However, baseline MRI screening at time of retinoblastoma diagnosis fails to detect the later diagnosed pineal TRb in 89% of patients. We modelled that an additional MRI performed at the age of 29 months picks up 53% of pineoblastomas in an asymptomatic phase. The detection rate increased to 72%, 87% and 92%, respectively, with 2, 3 and 4 additional MRIs. Conclusions An MRI of the brain in heritable retinoblastoma before the age of 12 months misses most pineoblastomas, while retinoblastomas are diagnosed most often before the age of 12 months. Optimally timed additional MRI scans of the brain can increase the asymptomatic detection rate of pineoblastoma.Peer reviewe

Achieving optimal cancer outcomes in East Africa through multidisciplinary partnership: a case study of the Kenyan National Retinoblastoma Strategy group.

BACKGROUND: Strategic, interdisciplinary partnerships are essential to addressing the complex drivers of health inequities that result in survival disparities worldwide. Take for example the aggressive early childhood eye cancer retinoblastoma, where survival reaches 97 % in resource-rich countries, but is as low 30 % in some resource-limited nations, where 92 % of the burden lies. This suggests a need for a multifaceted approach to achieve a tangible and sustainable increase in survival. METHODS: We assembled the history the Kenyan National Retinoblastoma Strategy (KNRbS), using information documented in NGO reports, grant applications, news articles, meeting agendas and summaries. We evaluated the KNRbS using the principles found in the guide for transboundary research partnerships developed by the Swiss Commission for Research Partnerships with Developing Countries. RESULTS: A nationally co-ordinated approach drawing input and expertise from multiple disciplines and sectors presented opportunities to optimise cure of children with retinoblastoma. Annual meetings were key to achieving the over 40 major outputs of the group's efforts, related to Awareness, Medical Care, Family Support and Resource Mobilization. Three features were found to be critical to the KNRbS success: multidisciplinarity, consistency and flexibility. CONCLUSION: The KNRbS has achieved a number of key outputs with limited financial investment. As a partnership, the KNRbS meets most of the criteria identified for success. Challenges remain in securing the long-term sustainability of its achievements. Elements of the Kenyan National Retinoblastoma Strategy may be useful to other developing countries struggling with limited survival of retinoblastoma and other cancers or rare diseases

Experimental Verification of a Predicted Intronic MicroRNA in Human NGFR Gene with a Potential Pro-Apoptotic Function

Neurotrophins (NTs) are a family of secreted growth factor proteins primarily involved in the regulation of survival and appropriate development of neural cells, functioning by binding to their specific (TrkA, TtkB, and TrkC) and/or common NGFR receptor. NGFR is the common receptor of NTs, binding with low-affinity to all members of the family. Among different functions assigned to NGFR, it is also involved in apoptosis induction and tumorigenesis processes. Interestingly, some of the functions of NGFR appear to be ligand-independent, suggesting a probable involvement of non-coding RNA residing within the sequence of the gene. Here, we are reporting the existence of a conserved putative microRNA, named Hsa-mir-6165 [EBI accession#: FR873488]. Transfection of a DNA segment corresponding to the pre-mir-6165 sequence in Hela cell line caused the generation of mature exogenous mir-6165 (a ∼200,000 fold overexpression). Furthermore, using specific primers, we succeeded to detect the endogenous expression of mir-6165 in several glioma cell lines and glioma primary tumors known to express NGFR. Similar to the pro-apoptotic role of NGFR in some cell types, overexpression of pre-mir-6165 in U87 cell line resulted in an elevated rate of apoptosis. Moreover, coordinated with the increased level of mir-6165 in the transfected U87 cell line, two of its predicted target genes (Pkd1 and DAGLA) were significantly down-regulated. The latter findings suggest that some of the previously attributed functions of NGFR could be explained indirectly by co-transcription of mir-6165 in the cells

Regulation of p14ARF expression by miR-24: a potential mechanism compromising the p53 response during retinoblastoma development

<p>Abstract</p> <p>Background</p> <p>Most human cancers show inactivation of both pRB- and p53-pathways. While retinoblastomas are initiated by loss of the <it>RB1 </it>tumor suppressor gene, <it>TP53 </it>mutations have not been found. High expression of the p53-antagonist MDM2 in human retinoblastomas may compromise p53 tumor surveillance so that <it>TP53 </it>mutations are not selected for in retinoblastoma tumorigenesis. We previously showed that p14^ARFprotein, which activates p53 by inhibiting MDM2, is low in retinoblastomas despite high mRNA expression.</p> <p>Methods</p> <p>In human fetal retinas, adult retinas, and retinoblastoma cells, we determined endogenous <it>p14^ARF</it>mRNA, ARF protein, and miR-24 expression, while integrity of p53 signalling in WERI-Rb1 cells was tested using an adenovirus vector expressing p14^ARF. To study p14^ARFbiogenesis, retinoblastoma cells were treated with the proteasome inhibitor, MG132, and siRNA against miR-24.</p> <p>Results</p> <p>In human retinoblastoma cell lines, <it>p14^ARF</it>mRNA was disproportionally high relative to the level of p14^ARFprotein expression, suggesting a perturbation of p14^ARFregulation. When p14^ARFwas over-expressed by an adenovirus vector, expression of p53 and downstream targets increased and cell growth was inhibited indicating an intact p14^ARF-p53 axis. To investigate the discrepancy between <it>p14^ARF</it>mRNA and protein in retinoblastoma, we examined p14^ARFbiogenesis. The proteasome inhibitor, MG132, did not cause p14^ARFaccumulation, although p14^ARFnormally is degraded by proteasomes. miR-24, a microRNA that represses p14^ARFexpression, is expressed in retinoblastoma cell lines and correlates with lower protein expression when compared to other cell lines with high <it>p14^ARF</it>mRNA. Transient over-expression of siRNA against miR-24 led to elevated p14^ARFprotein in retinoblastoma cells.</p> <p>Conclusions</p> <p>In retinoblastoma cells where high levels of <it>p14^ARF</it>mRNA are not accompanied by high p14^ARFprotein, we found a correlation between miR-24 expression and low p14^ARFprotein. p14^ARFprotein levels were restored without change in mRNA abundance upon miR-24 inhibition suggesting that miR-24 could functionally repress expression, effectively blocking p53 tumor surveillance. During retinal tumorigenesis, miR-24 may intrinsically compromise the p53 response to <it>RB1 </it>loss.</p

Performing identity: the case of the (Greek) Cypriot National Guard

Students of International Relations are taught that the modern nation-state has a monopoly on the (legitimate) use of violence. However, in the case of the Republic of Cyprus this does not seem to be the case, since its armed forces, the Cypriot National Guard (CNG), are intimately embedded within Greece’s military structure, and half the island remains under Turkish occupation. The colonization of Cyprus (1571–1960) and subsequent decolonization has led to the gradual construction of two rigid identities, Greek and Turkish, that have been institutionalized legally and imposed constitutionally. This paper seeks to answer two questions. First, how does the CNG perform and therefore constitute a ‘Greek identity’? Second, is this performance epistemically violent, hindering the formation of hybrid identities? We use autoethnography, interviews, and insights from Pierre Bourdieu’s concept of the habitus and Judith Butler’s performativity theory to explore these two questions. We argue that the CNG performs a Greek identity in three key configurations: 1) the operational link between the Greek Army and the CNG; 2) the explicit connection to both ancient and modern Greece through various CNG insignia and practices, including parades and marching songs; and 3) the entrenchment of the Greek Orthodox Church within its practices

Fine-Tuning Roles of Endogenous Brain-Derived Neurotrophic Factor, TrkB and Sortilin in Colorectal Cancer Cell Survival

International audienceBACKGROUND: Neurotrophin receptors were initially identified in neural cells. They were recently detected in some cancers in association with invasiveness, but the function of these tyrosine kinase receptors was not previously investigated in colorectal cancer (CRC) cells. METHODS AND FINDINGS: We report herein that human CRC cell lines synthesize the neural growth factor Brain-derived neurotrophic factor (BDNF) under stress conditions (serum starvation). In parallel, CRC cells expressed high- (TrkB) and low-affinity (p75(NTR)) receptors at the plasma membrane, whereas TrkA and TrkC, two other high affinity receptors for NGF and NT-3, respectively, were undetectable. We demonstrate that BDNF induced cell proliferation and had an anti-apoptotic effect mediated through TrkB, as assessed by K252a, a Trk pharmacologic inhibitor. It suppressed both cell proliferation and survival of CRC cells that do not express TrkA nor TrkC. In parallel to the increase of BDNF secretion, sortilin, a protein acting as a neurotrophin transporter as well as a co-receptor for p75(NTR), was increased in the cytoplasm of primary and metastatic CRC cells, which suggests that sortilin could regulate neurotrophin transport in these cells. However, pro-BDNF, also detected in CRC cells, was co-expressed with p75(NTR) at the cell membrane and co-localized with sortilin. In contrast to BDNF, exogenous pro-BDNF induced CRC apoptosis, which suggests that a counterbalance mechanism is involved in the control of CRC cell survival, through sortilin as the co-receptor for p75(NTR), the high affinity receptor for pro-neurotrophins. Likewise, we show that BDNF and TrkB transcripts (and not p75(NTR)) are overexpressed in the patients' tumors by comparison with their adjacent normal tissues, notably in advanced stages of CRC. CONCLUSION: Taken together, these results highlight that BDNF and TrkB are essential for CRC cell growth and survival in vitro and in tumors. This autocrine loop could be of major importance to define new targeted therapies

The functional loss of the retinoblastoma tumour suppressor is a common event in basal-like and luminal B breast carcinomas

Introduction Breast cancers can be classified using whole genome expression into distinct subtypes that show differences in prognosis. One of these groups, the basal-like subtype, is poorly differentiated, highly metastatic, genomically unstable, and contains specific genetic alterations such as the loss of tumour protein 53 (TP53). The loss of the retinoblastoma tumour suppressor encoded by the RB1 locus is a well-characterised occurrence in many tumour types; however, its role in breast cancer is less clear with many reports demonstrating a loss of heterozygosity that does not correlate with a loss of RB1 protein expression. Methods We used gene expression analysis for tumour subtyping and polymorphic markers located at the RB1 locus to assess the frequency of loss of heterozygosity in 88 primary human breast carcinomas and their normal tissue genomic DNA samples. Results RB1 loss of heterozygosity was observed at an overall frequency of 39%, with a high frequency in basal-like (72%) and luminal B (62%) tumours. These tumours also concurrently showed low expression of RB1 mRNA. p16INK4a was highly expressed in basal-like tumours, presumably due to a previously reported feedback loop caused by RB1 loss. An RB1 loss of heterozygosity signature was developed and shown to be highly prognostic, and was potentially a predictive marker of response to neoadjuvant chemotherapy. Conclusions These results suggest that the functional loss of RB1 is common in basal-like tumours, which may play a key role in dictating their aggressive biology and unique therapeutic responses