The importance of cancer prevention policies to inform and guide preventative and screening measures for people with intellectual disabilities: The COST project "Cancer- Understanding Prevention in Intellectual Disabilities".

Cancer is a global public health problem, but its exact prevalence in people with intellectual disabilities is still uncertain. This population, with limited health skills and complex health needs, faces many challenges in cancer prevention, screening, timely diagnosis and treatment. Furthermore, they are often underrepresented in general cancer prevention and screening policies across Europe, leading to widened disparities in health outcomes and premature mortality. Thus, unified national and local policies are needed to reduce inequalities and promoting a pan-European inclusion of people with intellectual disabilities. Our goal is to raise public awareness of this issue, including the involvement of people with intellectual disabilities, and promote engagement from relevant stakeholders. The COST Action 'Cancer- Understanding Prevention in Intellectual Disabilities' (CUPID) project will address health inequalities faced by people with intellectual disabilities in relation to cancer, and support the development of policy recommendations specifically tailored to their unique cognitive and healthcare needs, having a positive long-term impact on quality of life.

The role of PI3'-lipid signalling in melanoma initiation, progression and maintenance.

Phosphatidylinositol-3'-kinases (PI3Ks) are a family of lipid kinases that phosphorylate the 3' hydroxyl (OH) of the inositol ring of phosphatidylinositides (PI). Through their downstream effectors, PI3K generated lipids (PI3K-lipids hereafter) such as PI(3,4,5)P3 and PI(3,4)P2 regulate myriad biochemical and biological processes in both normal and cancer cells including responses to growth hormones and cytokines; the cell division cycle; cell death; cellular growth; angiogenesis; membrane dynamics; and autophagy and many aspects of cellular metabolism. Engagement of receptor tyrosine kinase by their cognate ligands leads to activation of members of the Class I family of PI3'-kinases (PI3Kα, ß, δ & γ) leading to accumulation of PI3K-lipids. Importantly, PI3K-lipid accumulation is antagonized by the hydrolytic action of a number of PI3K-lipid phosphatases, most notably the melanoma suppressor PTEN (lipid phosphatase and tensin homologue). Downstream of PI3K-lipid production, the protein kinases AKT1-3 are believed to be key effectors of PI3'-kinase signalling in cells. Indeed, in preclinical models, activation of the PI3K→AKT signalling axis cooperates with alterations such as expression of the BRAFV600E oncoprotein kinase to promote melanoma progression and metastasis. In this review, we describe the different classes of PI3K-lipid effectors, and how they may promote melanomagenesis, influence the tumour microenvironment, melanoma maintenance and progression to metastatic disease. We also provide an update on both FDA-approved or experimental inhibitors of the PI3K→AKT pathway that are currently being evaluated for the treatment of melanoma either in preclinical models or in clinical trials.

Incidence and type of restrictive practice use in nursing homes in Ireland.

BACKGROUND: Use of restrictive practices (RP) in care settings may sometimes be warranted but can also conflict with human rights. Research to date has focused primarily on physical and chemical RP, however other forms are also used. Better understanding of practice can inform RP reduction. This study describes the incidence of all types of RP use reported from nursing homes in Ireland. METHODS: RP notifications from nursing homes reported in 2020 were extracted from the Database of Statutory Notifications from Social Care in Ireland. The primary outcome measurement was the national incidence of use (frequency of RP/occupancy per 1000 residents) of categories and types of RP. Secondary outcome measurements such as percentage of facilities reporting use and quarterly median incidence of use in these facilities were calculated. RESULTS: Seventy thousand six hundred sixty-three RP uses were notified from 608 facilities (33,219 beds). National incidence of RP use per 1000 residents was, all categories: 2465.1, environmental: 1324.5, physical: 922.5, chemical: 141.1; 'other': 77.0. The most frequently used RPs per category were, environmental: door locks; physical: bedrails; chemical (where drug specified): antipsychotics; 'other': privacy. 90.5% of nursing homes reported using at least one type of RP in the 12-month period. Quarterly incidence of any RP use in these facilities was median 1.642 (IQR: 0.018 to 18.608) per bed. CONCLUSIONS: Nursing homes in Ireland regularly use RP; only 9.5% reported no RP use in the 12-month period. A wide variety of types of RP were reported. Environmental and 'other' (largely psychosocial) RP contributed notably to total RP use and warrant attention alongside the traditional focus on physical and chemical RP. Policy implications include the need for more comprehensive RP definitions.

Diminished WNT -> ß-catenin -> c-MYC signaling is a barrier for malignant progression of BRAFV600E-induced lung tumors.

Oncogene-induced senescence (OIS) is proposed as a cellular defense mechanism that restrains malignant progression of oncogene-expressing, initiated tumor cells. Consistent with this, expression of BRAF(V600E) in the mouse lung epithelium elicits benign tumors that fail to progress to cancer due to an apparent senescence-like proliferative arrest. Here we demonstrate that nuclear ß-catenin → c-MYC signaling is essential for early stage proliferation of BRAF(V600E)-induced lung tumors and is inactivated in the subsequent senescence-like state. Furthermore, either ß-catenin silencing or pharmacological blockade of Porcupine, an acyl-transferase essential for WNT ligand secretion and activity, significantly inhibited BRAF(V600E)-initiated lung tumorigenesis. Conversely, sustained activity of ß-catenin or c-MYC significantly enhanced BRAF(V600E)-induced lung tumorigenesis and rescued the anti-tumor effects of Porcupine blockade. These data indicate that early stage BRAF(V600E)-induced lung tumors are WNT-dependent and suggest that inactivation of WNT → ß-catenin → c-MYC signaling is a trigger for the senescence-like proliferative arrest that constrains the expansion and malignant progression of BRAF(V600E)-initiated lung tumors. Moreover, these data further suggest that the trigger for OIS in initiated BRAF(V600E)-expressing lung tumor cells is not simply a surfeit of signals from oncogenic BRAF but an insufficiency of WNT → ß-catenin → c-MYC signaling. These data have implications for understanding how genetic abnormalities cooperate to initiate and promote lung carcinogenesis.

The relationship between subjective socioeconomic status and health in adults with and without intellectual disability.

BACKGROUND: This study investigated if subjective socioeconomic status (SSS) is related to self-rated health (SRH) and objective indicators of health in people with and without intellectual disability. METHODS: Participants were 217 adults with, and 2350 adults without intellectual disability in Jersey. In the intellectual disability sample, 85 (39.2%) participants consented independently, while 132 (60.8%) participants consented through proxy procedures. The MacArthur Scale of Subjective Social Status was used to measure SSS. The Euro-Qol EQ-5D-5L and a five-point scale ranging from poor to excellent health were used to measure SRH. RESULTS: Higher SSS and younger age were predictors of better SRH for the proxy-report intellectual disability group. Being employed was associated with higher EQ-5D-5L index values for all intellectual disability groups. CONCLUSION: As SSS was only related to SRH in the proxy intellectual disability group, further research with a larger intellectual disability sample is needed to explore its utility further.

A comparison of the prevalence of health problems among adults with and without intellectual disability: A total administrative population study.

INTRODUCTION: There is considerable international research indicating health disparities between people with and without intellectual disabilities. It is important that comparative studies use representative population samples. This study compares a total administrative population of adults with intellectual disability to a random stratified general population sample. METHODS: An administrative population of 217 adults with intellectual disability and a random stratified sample of 2,350 adults without intellectual disability participated. A questionnaire using the International Classification of Diseases (ICD-10) Chapter Headings was administered to all participants to enable a like-for-like comparison. FINDINGS: Unadjusted comparisons identified that adults with intellectual disability have a greater prevalence of health problems. These problems start early in adulthood and continue throughout life. However, they were less likely to experience cancers and musculoskeletal diseases. CONCLUSIONS: These findings are consistent with the hypothesis that adults with intellectual disabilities have greater prevalence rates of health problems than the general population.

The intermediate-activity (L597V)BRAF mutant acts as an epistatic modifier of oncogenic RAS by enhancing signaling through the RAF/MEK/ERK pathway.

(L597V)BRAF mutations are acquired somatically in human cancer samples and are frequently coincident with RAS mutations. Germline (L597V)BRAF mutations are also found in several autosomal dominant developmental conditions known as RASopathies, raising the important question of how the same mutation can contribute to both pathologies. Using a conditional knock-in mouse model, we show that endogenous expression of (L597V)Braf leads to approximately twofold elevated Braf kinase activity and weak activation of the Mek/Erk pathway. This is associated with induction of RASopathy hallmarks including cardiac abnormalities and facial dysmorphia but is not sufficient for tumor formation. We combined (L597V)Braf with (G12D)Kras and found that (L597V)Braf modified (G12D)Kras oncogenesis such that fibroblast transformation and lung tumor development were more reminiscent of that driven by the high-activity (V600E)Braf mutant. Mek/Erk activation levels were comparable with those driven by (V600E)Braf in the double-mutant cells, and the gene expression signature was more similar to that induced by (V600E)Braf than (G12D)Kras. However, unlike (V600E)Braf, Mek/Erk pathway activation was mediated by both Craf and Braf, and ATP-competitive RAF inhibitors induced paradoxical Mek/Erk pathway activation. Our data show that weak activation of the Mek/Erk pathway underpins RASopathies, but in cancer, (L597V)Braf epistatically modifies the transforming effects of driver oncogenes.

Abrogation of BRAFV600E-induced senescence by PI3K pathway activation contributes to melanomagenesis.

Human melanocytic nevi (moles) are benign lesions harboring activated oncogenes, including BRAF. Although this oncogene initially acts mitogenically, eventually, oncogene-induced senescence (OIS) ensues. Nevi can infrequently progress to melanomas, but the mechanistic relationship with OIS is unclear. We show here that PTEN depletion abrogates BRAF(V600E)-induced senescence in human fibroblasts and melanocytes. Correspondingly, in established murine BRAF(V600E)-driven nevi, acute shRNA-mediated depletion of PTEN prompted tumor progression. Furthermore, genetic analysis of laser-guided microdissected human contiguous nevus-melanoma specimens recurrently revealed identical mutations in BRAF or NRAS in adjacent benign and malignant melanocytes. The PI3K pathway was often activated through either decreased PTEN or increased AKT3 expression in melanomas relative to their adjacent nevi. Pharmacologic PI3K inhibition in melanoma cells suppressed proliferation and induced the senescence-associated tumor suppressor p15(INK4B). This treatment also eliminated subpopulations resistant to targeted BRAF(V600E) inhibition. Our findings suggest that a significant proportion of melanomas arise from nevi. Furthermore, these results demonstrate that PI3K pathway activation serves as a rate-limiting event in this setting, acting at least in part by abrogating OIS. The reactivation of senescence features and elimination of cells refractory to BRAF(V600E) inhibition by PI3K inhibition warrants further investigation into the therapeutic potential of simultaneously targeting these pathways in melanoma.

Modelling vemurafenib resistance in melanoma reveals a strategy to forestall drug resistance.

Mutational activation of BRAF is the most prevalent genetic alteration in human melanoma, with ≥50% of tumours expressing the BRAF(V600E) oncoprotein. Moreover, the marked tumour regression and improved survival of late-stage BRAF-mutated melanoma patients in response to treatment with vemurafenib demonstrates the essential role of oncogenic BRAF in melanoma maintenance. However, as most patients relapse with lethal drug-resistant disease, understanding and preventing mechanism(s) of resistance is critical to providing improved therapy. Here we investigate the cause and consequences of vemurafenib resistance using two independently derived primary human melanoma xenograft models in which drug resistance is selected by continuous vemurafenib administration. In one of these models, resistant tumours show continued dependency on BRAF(V600E)→MEK→ERK signalling owing to elevated BRAF(V600E) expression. Most importantly, we demonstrate that vemurafenib-resistant melanomas become drug dependent for their continued proliferation, such that cessation of drug administration leads to regression of established drug-resistant tumours. We further demonstrate that a discontinuous dosing strategy, which exploits the fitness disadvantage displayed by drug-resistant cells in the absence of the drug, forestalls the onset of lethal drug-resistant disease. These data highlight the concept that drug-resistant cells may also display drug dependency, such that altered dosing may prevent the emergence of lethal drug resistance. Such observations may contribute to sustaining the durability of the vemurafenib response with the ultimate goal of curative therapy for the subset of melanoma patients with BRAF mutations.

Proceedings of the fifth international RASopathies symposium: When development and cancer intersect.

This report summarizes and highlights the fifth International RASopathies Symposium: When Development and Cancer Intersect, held in Orlando, Florida in July 2017. The RASopathies comprise a recognizable pattern of malformation syndromes that are caused by germ line mutations in genes that encode components of the RAS/mitogen-activated protein kinase (MAPK) pathway. Because of their common underlying pathogenetic etiology, there is significant overlap in their phenotypic features, which includes craniofacial dysmorphology, cardiac, cutaneous, musculoskeletal, gastrointestinal and ocular abnormalities, neurological and neurocognitive issues, and a predisposition to cancer. The RAS pathway is a well-known oncogenic pathway that is commonly found to be activated in somatic malignancies. As in somatic cancers, the RASopathies can be caused by various pathogenetic mechanisms that ultimately impact or alter the normal function and regulation of the MAPK pathway. As such, the RASopathies represent an excellent model of study to explore the intersection of the effects of dysregulation and its consequence in both development and oncogenesis.

An ultraviolet-radiation-independent pathway to melanoma carcinogenesis in the red hair/fair skin background.

People with pale skin, red hair, freckles and an inability to tan--the 'red hair/fair skin' phenotype--are at highest risk of developing melanoma, compared to all other pigmentation types. Genetically, this phenotype is frequently the product of inactivating polymorphisms in the melanocortin 1 receptor (MC1R) gene. MC1R encodes a cyclic AMP-stimulating G-protein-coupled receptor that controls pigment production. Minimal receptor activity, as in red hair/fair skin polymorphisms, produces the red/yellow pheomelanin pigment, whereas increasing MC1R activity stimulates the production of black/brown eumelanin. Pheomelanin has weak shielding capacity against ultraviolet radiation relative to eumelanin, and has been shown to amplify ultraviolet-A-induced reactive oxygen species. Several observations, however, complicate the assumption that melanoma risk is completely ultraviolet-radiation-dependent. For example, unlike non-melanoma skin cancers, melanoma is not restricted to sun-exposed skin and ultraviolet radiation signature mutations are infrequently oncogenic drivers. Although linkage of melanoma risk to ultraviolet radiation exposure is beyond doubt, ultraviolet-radiation-independent events are likely to have a significant role. Here we introduce a conditional, melanocyte-targeted allele of the most common melanoma oncoprotein, BRAF(V600E), into mice carrying an inactivating mutation in the Mc1r gene (these mice have a phenotype analogous to red hair/fair skin humans). We observed a high incidence of invasive melanomas without providing additional gene aberrations or ultraviolet radiation exposure. To investigate the mechanism of ultraviolet-radiation-independent carcinogenesis, we introduced an albino allele, which ablates all pigment production on the Mc1r(e/e) background. Selective absence of pheomelanin synthesis was protective against melanoma development. In addition, normal Mc1r(e/e) mouse skin was found to have significantly greater oxidative DNA and lipid damage than albino-Mc1r(e/e) mouse skin. These data suggest that the pheomelanin pigment pathway produces ultraviolet-radiation-independent carcinogenic contributions to melanomagenesis by a mechanism of oxidative damage. Although protection from ultraviolet radiation remains important, additional strategies may be required for optimal melanoma prevention.

Professional collaboration in searching the evidence for an ill-defined concept.

This paper outlines the inter-professional collaboration of the authors, a PhD student, his supervisor and an information professional, to systematically search the literature for an ill-defined concept. The research question posed for the scoping literature review indicated that the topic, the subjective socio-economic status and health of adults with intellectual disabilities, was rare. The need for a methodological search process was therefore identified and successfully carried out. The paper presents an analysis of the processes and the collaboration involved in developing a successful search strategy. The resulting transformative learning by the researcher of the professional practice of the information specialist illuminates their facilitating and supportive role in advancing health related research. F.J.

p53 constrains progression to anaplastic thyroid carcinoma in a Braf-mutant mouse model of papillary thyroid cancer.

Anaplastic thyroid carcinoma (ATC) has among the worst prognoses of any solid malignancy. The low incidence of the disease has in part precluded systematic clinical trials and tissue collection, and there has been little progress in developing effective therapies. v-raf murine sarcoma viral oncogene homolog B (BRAF) and tumor protein p53 (TP53) mutations cooccur in a high proportion of ATCs, particularly those associated with a precursor papillary thyroid carcinoma (PTC). To develop an adult-onset model of BRAF-mutant ATC, we generated a thyroid-specific CreER transgenic mouse. We used a Cre-regulated Braf(V600E) mouse and a conditional Trp53 allelic series to demonstrate that p53 constrains progression from PTC to ATC. Gene expression and immunohistochemical analyses of murine tumors identified the cardinal features of human ATC including loss of differentiation, local invasion, distant metastasis, and rapid lethality. We used small-animal ultrasound imaging to monitor autochthonous tumors and showed that treatment with the selective BRAF inhibitor PLX4720 improved survival but did not lead to tumor regression or suppress signaling through the MAPK pathway. The combination of PLX4720 and the mapk/Erk kinase (MEK) inhibitor PD0325901 more completely suppressed MAPK pathway activation in mouse and human ATC cell lines and improved the structural response and survival of ATC-bearing animals. This model expands the limited repertoire of autochthonous models of clinically aggressive thyroid cancer, and these data suggest that small-molecule MAPK pathway inhibitors hold clinical promise in the treatment of advanced thyroid carcinoma.

Abnormal Ras signaling in Costello syndrome (CS) negatively regulates enamel formation.

RASopathies are syndromes caused by gain-of-function mutations in the Ras signaling pathway. One of these conditions, Costello syndrome (CS), is typically caused by an activating de novo germline mutation in HRAS and is characterized by a wide range of cardiac, musculoskeletal, dermatological and developmental abnormalities. We report that a majority of individuals with CS have hypo-mineralization of enamel, the outer covering of teeth, and that similar defects are present in a CS mouse model. Comprehensive analysis of the mouse model revealed that ameloblasts, the cells that generate enamel, lacked polarity, and the ameloblast progenitor cells were hyperproliferative. Ras signals through two main effector cascades, the mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3-kinase (PI3K) pathways. To determine through which pathway Ras affects enamel formation, inhibitors targeting either PI3K or MEK 1 and 2 (MEK 1/2), kinases in the MAPK pathway, were utilized. MEK1/2 inhibition rescued the hypo-mineralized enamel, normalized the ameloblast polarity defect and restored normal progenitor cell proliferation. In contrast, PI3K inhibition only corrected the progenitor cell proliferation phenotype. We demonstrate for the first time the central role of Ras signaling in enamel formation in CS individuals and present the mouse incisor as a model system to dissect the roles of the Ras effector pathways in vivo.

Phenformin enhances the therapeutic benefit of BRAF(V600E) inhibition in melanoma.

Biguanides, such as the diabetes therapeutics metformin and phenformin, have demonstrated antitumor activity both in vitro and in vivo. The energy-sensing AMP-activated protein kinase (AMPK) is known to be a major cellular target of biguanides. Based on our discovery of cross-talk between the AMPK and v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) signaling pathways, we investigated the antitumor effects of combining phenformin with a BRAF inhibitor PLX4720 on the proliferation of BRAF-mutated melanoma cells in vitro and on BRAF-driven tumor growth in vivo. Cotreatment of BRAF-mutated melanoma cell lines with phenformin and PLX4720 resulted in synergistic inhibition of cell viability, compared with the effects of the single agent alone. Moreover, treatment with phenformin significantly delayed the development of resistance to PLX4720 in cultured melanoma cells. Biochemical analyses showed that phenformin and PLX4720 exerted cooperative effects on inhibiting mTOR signaling and inducing apoptosis. Noticeably, phenformin selectively targeted subpopulations of cells expressing JARID1B, a marker for slow cycling melanoma cells, whereas PLX4720 selectively targeted JARID1B-negative cells. Finally, in contrast to their use as single agents, the combination of phenformin and PLX4720 induced tumor regression in both nude mice bearing melanoma xenografts and in a genetically engineered BRAF(V600E)/PTEN(null)-driven mouse model of melanoma. These results strongly suggest that significant therapeutic advantage may be achieved by combining AMPK activators such as phenformin with BRAF inhbitors for the treatment of melanoma.

Regulated temporal-spatial astrocyte precursor cell proliferation involves BRAF signalling in mammalian spinal cord.

Expansion of astrocyte populations in the central nervous system is characteristic of evolutionarily more complex organisms. However, regulation of mammalian astrocyte precursor proliferation during development remains poorly understood. Here, we used Aldh1L1-GFP to identify two morphologically distinct types of proliferative astrocyte precursors: radial glia (RG) in the ventricular zone and a second cell type we call an 'intermediate astrocyte precursor' (IAP) located in the mantle region of the spinal cord. Astrogenic RG and IAP cells proliferated in a progressive ventral-to-dorsal fashion in a tight window from embryonic day 13.5 until postnatal day 3, which correlated precisely with the pattern of active ERK signalling. Conditional loss of BRAF function using BLBP-cre resulted in a 20% decrease in astrocyte production, whereas expression of activated BRAFV600E resulted in astrocyte hyperproliferation. Interestingly, BRAFV600E mitogenic effects in astrocytes were restricted, in part, by the function of p16INK4A-p19(ARF), which limited the temporal epoch for proliferation. Together, these findings suggest that astrocyte precursor proliferation involves distinct RG and IAP cells; is subjected to temporal and spatial control; and depends in part on BRAF signalling at early stages of mammalian spinal cord development.

Cooperative interactions of BRAFV600E kinase and CDKN2A locus deficiency in pediatric malignant astrocytoma as a basis for rational therapy.

Although malignant astrocytomas are a leading cause of cancer-related death in children, rational therapeutic strategies are lacking. We previously identified activating mutations of v-raf murine sarcoma viral oncogene homolog B1 (BRAF) (BRAF(T1799A) encoding BRAF(V600E)) in association with homozygous cyclin-dependent kinase inhibitor 2A (CDKN2A, encoding p14ARF and p16Ink4a) deletions in pediatric infiltrative astrocytomas. Here we report that BRAF(V600E) expression in neural progenitors (NPs) is insufficient for tumorigenesis and increases NP cellular differentiation as well as apoptosis. In contrast, astrocytomas are readily generated from NPs with additional Ink4a-Arf deletion. The BRAF(V600E) inhibitor PLX4720 significantly increased survival of mice after intracranial transplant of genetically relevant murine or human astrocytoma cells. Moreover, combination therapy using PLX4720 plus the Cyclin-dependent kinase (CDK) 4/6-specific inhibitor PD0332991 further extended survival relative to either monotherapy. Our findings indicate a rational therapeutic strategy for treating a subset of pediatric astrocytomas with BRAF(V600E) mutation and CDKN2A deficiency.