Communication strategies used by medical physicians when delivering bad news at the Maputo Central Hospital, Mozambique: a cross-sectional study.

BACKGROUND: Physicians' communication with patients and their families is important during both the disease diagnosis and prognosis stages and through the follow-up process. Effective physician communication improves patients' quality of life and satisfaction with care and helps reduce suffering for those newly diagnosed with advanced progressive illnesses. This study aims to identify the communication strategies physicians use in the transition to palliative care and how these professionals perceive their academic and clinical preparation concerning this task. METHODS: A cross-sectional and quantitative study. Physicians providing palliative care at the Maputo Central Hospital, Mozambique, were invited to complete a 17-question questionnaire. This questionnaire was based on a Brazilian adaptation of the Setting-Perception-Invitation-Knowledge-Emotions-Strategy (SPIKES) tool, the P-A-C-I-E-N-T-E protocol, with additional questions regarding socio-demographic details and the integration of "communication of bad news" into hospital training. RESULTS: Of the 121 participants, 62 (51.2%) were male, and 110 (90.9%) were general practitioners, with a median age of 36 years old. They had worked in clinical practice for a median of 8 years and in their current department for three years. The majority of the participants considered that they have an acceptable or good level of bad news communication skills and believed that they do it in a clear and empathic way, paying attention to the patient's requests and doubts; however, most were not aware of the existing tools to assist them in this task and suggested that delivering bad news ought to be integrated into the undergraduate medical course and included in hospital training. CONCLUSIONS: This study adds to our understanding of physicians' strategies when communicating bad news in the context of palliative care at one Mozambique hospital. As palliative care is not fully implemented in Mozambique, it is important to use protocols suitable to the country's healthcare level to improve how doctors deal with patients and their family members.

What 20 years of research has taught us about the TP53 p.R337H mutation.

The p53 tumor suppressor transcriptionally regulates a myriad of genes involved in cell cycle control, DNA repair, cell survival, and cell metabolism and represents one of the most well-studied inhibitors of tumorigenesis. Since the discovery of TP53 in 1979, somatic mutations have been shown to be extremely common; more than 50% of human cancers carry loss-of-function mutations in TP53. Inherited or germline TP53 mutations are rare and are involved in complex hereditary cancer predisposition disorders, and affected family members can develop diverse tumor types and multiple primary cancers at young ages. In Brazil, a fascinating history of p53 and cancer predisposition began in the year 2000 with identification of the TP53 p.R337H mutation in close association with the development of adrenocortical tumors. In these past 20 years, much has been learned about the genetics and biochemistry of this mutation, which is widespread in Brazil because of a founder effect. This review highlights the contributions of TP53 p.R337H research over the last 20 years, the findings of which have sparked passionate debate among researchers worldwide, to understanding cancer predisposition in Brazilian individuals and families.

A common polymorphism in the retinoic acid pathway modifies adrenocortical carcinoma age-dependent incidence.

BACKGROUND: Genome-wide association studies (GWASs) have enriched the fields of genomics and drug development. Adrenocortical carcinoma (ACC) is a rare cancer with a bimodal age distribution and inadequate treatment options. Paediatric ACC is frequently associated with TP53 mutations, with particularly high incidence in Southern Brazil due to the TP53 p.R337H (R337H) germline mutation. The heterogeneous risk among carriers suggests other genetic modifiers could exist. METHODS: We analysed clinical, genotype and gene expression data derived from paediatric ACC, R337H carriers, and adult ACC patients. We restricted our analyses to single nucleotide polymorphisms (SNPs) previously identified in GWASs to associate with disease or human traits. RESULTS: A SNP, rs971074, in the alcohol dehydrogenase 7 gene significantly and reproducibly associated with allelic differences in ACC age-of-onset in both cohorts. Patients homozygous for the minor allele were diagnosed up to 16 years earlier. This SNP resides in a gene involved in the retinoic acid (RA) pathway and patients with differing levels of RA pathway gene expression in their tumours associate with differential ACC progression. CONCLUSIONS: These results identify a novel genetic component to ACC development that resides in the retinoic acid pathway, thereby informing strategies to develop management, preventive and therapeutic treatments for ACC.

An update on the central nervous system manifestations of Li-Fraumeni syndrome.

Li-Fraumeni syndrome (LFS), caused by the germline mutations in the TP53 gene, leads to significant lifetime risk to cancer in the central nervous system. Recognition of LFS, and elucidating its underlying cause has had a remarkable effect on our knowledge of the biology of brain tumors and represents a significant opportunity for cancer surveillance and screening. In this review, we discuss the historical context of the LFS with an emphasis on the clinicopathologic implications in clincal diagnosis, germline testing, and clinical management of brain tumor patients.

Malignant rhabdoid tumors originating within and outside the central nervous system are clinically and molecularly heterogeneous.

Multifocal synchronous or metachronous atypical teratoid rhabdoid tumors (ATRTs) and non-central nervous system malignant rhabdoid tumors (extra-CNS MRTs) are rare cancers. We reviewed the clinical and radiologic characteristics of affected patients seen at our institution. Genotyping and analysis of copy number abnormalities (CNAs) in SMARCB1 were performed in germline and tumor samples. Tumor samples underwent genome-wide DNA methylation and CNA analysis. The median age at diagnosis of 21 patients was 0.6 years. Two-thirds of ATRTs and extra-CNS MRTs were diagnosed synchronously. Although kidney tumors predominated, including two patients with bilateral involvement, at least 30% of cases lacked renal involvement. Histopathologic review confirmed MRTs in all cases and INI1 expression loss in all tumors tested. Fourteen (78%) of 18 patients tested had heterozygous germline SMARCB1 abnormalities. At least one allelic SMARCB1 abnormality was confirmed in 81 and 88% of ATRTs and extra-CNS MRTs, respectively. Unsupervised hierarchical clustering analysis of DNA methylation in 27 tumors and comparison with a reference group of 150 ATRTs classified the CNS tumors (n = 14) as sonic hedgehog (64%), tyrosinase (21%), and MYC (14%). The MYC subgroup accounted for 85% of 13 extra-CNS MRTs. Of 16 paired ATRTs and extra-CNS MRTs, the tumors in seven of eight patients showed a different pattern of genome-wide DNA methylation and/or CNAs suggestive of non-clonal origin. CNS and extra-CNS tumors had an identical SMARCB1 amplification (n = 1) or very similar DNA methylation pattern (n = 1) suggestive of clonal origin. All patients died of tumor progression. The clinical and molecular characteristics of multifocal ATRTs and extra-CNS MRTs are heterogeneous with most patients harboring a cancer predisposition. Although independent tumor origin was confirmed in most cases, metastatic spread was also documented. The recognition of their distinct molecular characteristics is critical in selecting new biologic therapies against these deadly cancers.

Anesthetic Care in Mozambique.

BACKGROUND: The World Bank and Lancet Commission in 2015 have prioritized surgery in Low-Income Countries (LIC) and Lower-Middle Income Countries (LMICs). This is consistent with the shift in the global burden of disease from communicable to noncommunicable diseases over the past 20 years. Essential surgery must be performed safely, with adequate anesthesia monitoring and intervention. Unfortunately, a huge barrier to providing safe surgery includes the paucity of an anesthesia workforce. In this study, we qualitatively evaluated the anesthesia capacity of Mozambique, a LIC in Africa with limited access to anesthesia and safe surgical care. Country-based solutions are suggested that can expand to other LIC and LMICs. METHODS: A comprehensive review of the Mozambique anesthesia system was conducted through interviews with personnel in the Ministry of Health (MOH), a school of medicine, a public central referral hospital, a general first referral hospital, a private care hospital, and leaders in the physician anesthesia community. Personnel databases were acquired from the MOH and Maputo Central Hospital. RESULTS: Quantitative results reveal minimal anesthesia capacity (290 anesthesia providers for a population of >25 million or 0.01:10,000). The majority of physician anesthesiologists practice in urban settings, and many work in the private sector. There is minimal capacity for growth given only 1 Mozambique anesthesia residency with inadequate resources. The most commonly perceived barriers to safe anesthesia in this critical shortage are lack of teachers, lack of medical student interest in and exposure to anesthesia, need for more schools, low allocation to anesthesia from the list of available specialist prospects by MOH, and low public payments to anesthesiologists. Qualitative results show assets of a good health system design, a supportive environment for learning in the residency, improvement in anesthetic care in past decades, and a desire for more educational opportunities and teachers. CONCLUSIONS: Mozambique has a strong health system design but few resources for surgery and safe anesthesia. At present, similar to other LICs, human resources, access to essential medicines, and safety monitoring limit safe anesthesia in Mozambique.

The E180splice mutation in the GHR gene causing Laron syndrome: witness of a Sephardic Jewish exodus from the Iberian Peninsula to the New World?

Laron syndrome (LS) is a genetic disorder caused by mutations in the growth hormone receptor (GHR) gene. The most frequent GHR mutation is E180splice (rs121909360), which was initially found in an inbred population of Spanish descent in Ecuador and subsequently in Israel, Brazil, Chile, and the United States. The aim of the present study is to determine if the E180splice mutation arose from a common origin. We studied 22 patients with LS from Ecuador, Israel (of Moroccan origin), Brazil, Chile, and the United States (of Mexican origin) who were homozygous for the E180splice mutation and compared them to control individuals for markers surrounding the GHR, intragenic polymorphisms, and Y-chromosome STR. An identical haplotype was found in all but one of the subjects carrying the E180splice mutation: D5S665: 150/150; D5S2082: 192/192; D5S2087: 246/246; rs6179 G/G; and rs6180 C/C. One patient differed from the others only at D5S2082 (168/192). This haplotype is rare (~1%) in control individuals and confirmed that the E180splice-associated haplotype was not derived from independent origins but represented recombination from a common ancestor. The analysis of paternal lineage markers showed that 50% belong to haplogroup R1b (found in Portugal and Spain) and 40% to haplogroups J and E (typical in the Middle East and in Eastern European Jews). The germline E180Splice mutation appears to have originated from a single common ancestor. The presence of Y-chromosome markers associated with Sephardic populations in persons harboring the E180splice mutation provides genetic evidence in support of the historical tracking of the exodus of this specific population.

Pediatric Adrenocortical Carcinoma: The Nuts and Bolts of Diagnosis and Treatment and Avenues for Future Discovery.

Adrenocortical tumors (ACTs) are infrequent neoplasms in children and adolescents and are typically associated with clinical symptoms reflective of androgen overproduction. Pediatric ACTs typically occur in the context of a germline TP53 mutation, can be cured when diagnosed at an early stage, but are difficult to treat when advanced or associated with concurrent TP53 and ATRX alterations. Recent work has demonstrated DNA methylation patterns suggestive of prognostic significance. While current treatment standards rely heavily upon surgical resection, chemotherapy, and hormonal modulation, small cohort studies suggest promise for multi-tyrosine kinases targeting anti-angiogenic pathways or immunomodulatory therapies. Future work will focus on novel risk stratification algorithms and combination therapies intended to mitigate toxicity for patients with perceived low-risk disease while intensifying therapy or accelerating discoveries aimed at improving survival for patients with difficult-to-treat disease.

Multiple TP53 p.R337H haplotypes and implications for tumor susceptibility.

The germline TP53 p.R337H mutation is reported as the most common germline TP53 variant. It exists at a remarkably high frequency in the population of southeast Brazil as founder mutation in two distinct haplotypes with the most frequent co-segregating with the p.E134∗ variant of the XAF1 tumor suppressor and an increased cancer risk. Founder mutations demonstrate linkage disequilibrium with neighboring genetic polymorphic markers that can be used to identify the founder variant in different geographic regions and diverse populations. We report here a shared haplotype among Brazilian, Portuguese, and Spanish families and the existence of three additional distinct TP53 p.R337H alleles. Mitochondrial DNA sequencing and Y-STR profiling of Brazilian carriers of the founder TP53 p.R337H allele reveal an excess of Native American haplogroups in maternal lineages and exclusively European haplogroups in paternal lineages, consistent with communities established through male European settlers with extensive intermarriage with Indigenous women. The identification of founder and independent TP53 p.R337H alleles underlines the importance for considering the haplotype as a functional unit and the additive effects of constitutive polymorphisms and associated variants in modifier genes that can influence the cancer phenotype.

International consensus on mitotane treatment in pediatric patients with adrenal cortical tumors: indications, therapy, and management of adverse effects.

OBJECTIVE: Mitotane is an important cornerstone in the treatment of pediatric adrenal cortical tumors (pACC), but experience with the drug in the pediatric age group is still limited and current practice is not guided by robust evidence. Therefore, we have compiled international consensus statements from pACC experts on mitotane indications, therapy, and management of adverse effects. METHODS: A Delphi method with 3 rounds of questionnaires within the pACC expert consortium of the international network groups European Network for the Study of Adrenal Tumors pediatric working group (ENSAT-PACT) and International Consortium of pediatric adrenocortical tumors (ICPACT) was used to create 21 final consensus statements. RESULTS: We divided the statements into 4 groups: environment, indications, therapy, and adverse effects. We reached a clear consensus for mitotane treatment for advanced pACC with stages III and IV and with incomplete resection/tumor spillage. For stage II patients, mitotane is not generally indicated. The timing of initiating mitotane therapy depends on the clinical condition of the patient and the setting of the planned therapy. We recommend a starting dose of 50 mg/kg/d (1500 mg/m²/d) which can be increased up to 4000 mg/m2/d. Blood levels should range between 14 and 20 mg/L. Duration of mitotane treatment depends on the clinical risk profile and tolerability. Mitotane treatment causes adrenal insufficiency in virtually all patients requiring glucocorticoid replacement shortly after beginning. As the spectrum of adverse effects of mitotane is wide-ranging and can be life-threatening, frequent clinical and neurological examinations (every 2-4 weeks), along with evaluation and assessment of laboratory values, are required. CONCLUSIONS: The Delphi method enabled us to propose an expert consensus statement, which may guide clinicians, further adapted by local norms and the individual patient setting. In order to generate evidence, well-constructed studies should be the focus of future efforts.

How Low Back Pain is Managed-A Mixed-Methods Study in 32 Countries. Part 2 of Low Back Pain in Low- and Middle-Income Countries Series.

BACKGROUND: The Lancet Low Back Pain (LBP) Series highlighted the lack of LBP data from low- and middle-income countries (LMICs). The study aimed to describe (1) what LBP care is currently delivered in LMICs and (2) how that care is delivered. DESIGN: An online mixed-methods study. METHODS: A Consortium for LBP in LMICs (n = 65) was developed with an expert panel of leading LBP researchers (>2 publications on LBP) and multidisciplinary clinicians and patient partners with 5 years of clinical/lived LBP experience in LMICs. Quantitative data were analyzed using descriptive statistics. Two researchers independently analyzed qualitative data using inductive and deductive coding and developed a thematic framework. RESULTS: Forty-seven (85%) of 55 invited panel members representing 32 LMICs completed the survey (38% women, 62% men). The panel included clinicians (34%), researchers (28%), educators (6%), and people with lived experience (4%). Pharmacotherapies and electrophysiological agents were the most used LBP treatments. The thematic framework comprised 8 themes: (1) self-management is ubiquitous, (2) medicines are the cornerstone, (3) traditional therapies have a place, (4) society plays an important role, (5) imaging use is very common, (6) reliance on passive approaches, (7) social determinants influence LBP care pathway, and (8) health systems are ill-prepared to address LBP burden. CONCLUSION: LBP care in LMICs did not consistently align with the best available evidence. Findings will help research prioritization in LMICs and guide global LBP clinical guidelines. J Orthop Sports Phys Ther 2024;54(8):560-572. Epub 11 April 2024. doi:10.2519/jospt.2024.12406.

Clinical and functional analysis of the germline TP53 p.K164E acetylation site variant.

TP53 plays a critical role as a tumor suppressor by controlling cell cycle progression, DNA repair, and apoptosis. Post-translational modifications such as acetylation of specific lysine residues in the DNA binding and carboxy-terminus regulatory domains modulate its tumor suppressor activities. In this study, we addressed the functional consequences of the germline TP53 p.K164E (NM_000546.5: c.490A>G) variant identified in a patient with early-onset breast cancer and a significant family history of cancer. K164 is a conserved residue located in the L2 loop of the p53 DNA binding domain that is post-translationally modified by acetylation. In silico, in vitro, and in vivo analyses demonstrated that the glutamate substitution at K164 marginally destabilizes the p53 protein structure but significantly impairs sequence-specific DNA binding, transactivation, and tumor cell growth inhibition. Although p.K164E is currently considered a variant of unknown significance by different clinical genetic testing laboratories, the clinical and laboratory-based findings presented here provide strong evidence to reclassify TP53 p.K164E as a likely pathogenic variant.

The Genetic and Epigenetic Features of Bilateral Wilms Tumor Predisposition: A Report from the Children's Oncology Group AREN18B5-Q Study.

This study comprehensively evaluated the landscape of genetic and epigenetic events that predispose to synchronous bilateral Wilms tumor (BWT). We performed whole exome or whole genome sequencing, total-strand RNA-seq, and DNA methylation analysis using germline and/or tumor samples from 68 patients with BWT from St. Jude Children's Research Hospital and the Children's Oncology Group. We found that 25/61 (41%) of patients evaluated harbored pathogenic or likely pathogenic germline variants, with WT1 (14.8%), NYNRIN (6.6%), TRIM28 (5%) and the BRCA-related genes (5%) BRCA1, BRCA2, and PALB2 being most common. Germline WT1 variants were strongly associated with somatic paternal uniparental disomy encompassing the 11p15.5 and 11p13/WT1 loci and subsequent acquired pathogenic CTNNB1 variants. Somatic coding variants or genome-wide copy number alterations were almost never shared between paired synchronous BWT, suggesting that the acquisition of independent somatic variants leads to tumor formation in the context of germline or early embryonic, post-zygotic initiating events. In contrast, 11p15.5 status (loss of heterozygosity, loss or retention of imprinting) was shared among paired synchronous BWT in all but one case. The predominant molecular events for BWT predisposition include pathogenic germline variants or post-zygotic epigenetic hypermethylation at the 11p15.5 H19/ICR1 locus (loss of imprinting). This study demonstrates that post-zygotic somatic mosaicism for 11p15.5 hypermethylation/loss of imprinting is the single most common initiating molecular event predisposing to BWT. Evidence of somatic mosaicism for 11p15.5 loss of imprinting was detected in leukocytes of a cohort of BWT patients and long-term survivors, but not in unilateral Wilms tumor patients and long-term survivors or controls, further supporting the hypothesis that post-zygotic 11p15.5 alterations occurred in the mesoderm of patients who go on to develop BWT. Due to the preponderance of BWT patients with demonstrable germline or early embryonic tumor predisposition, BWT exhibits a unique biology when compared to unilateral Wilms tumor and therefore warrants continued refinement of its own treatment-relevant biomarkers which in turn may inform directed treatment strategies in the future.

Genetic and epigenetic features of bilateral Wilms tumor predisposition in patients from the Children's Oncology Group AREN18B5-Q.

Developing synchronous bilateral Wilms tumor suggests an underlying (epi)genetic predisposition. Here, we evaluate this predisposition in 68 patients using whole exome or genome sequencing (n = 85 tumors from 61 patients with matched germline blood DNA), RNA-seq (n = 99 tumors), and DNA methylation analysis (n = 61 peripheral blood, n = 29 non-diseased kidney, n = 99 tumors). We determine the predominant events for bilateral Wilms tumor predisposition: 1)pre-zygotic germline genetic variants readily detectable in blood DNA [WT1 (14.8%), NYNRIN (6.6%), TRIM28 (5%), and BRCA-related genes (5%)] or 2)post-zygotic epigenetic hypermethylation at 11p15.5 H19/ICR1 that may require analysis of multiple tissue types for diagnosis. Of 99 total tumor specimens, 16 (16.1%) have 11p15.5 normal retention of imprinting, 25 (25.2%) have 11p15.5 copy neutral loss of heterozygosity, and 58 (58.6%) have 11p15.5 H19/ICR1 epigenetic hypermethylation (loss of imprinting). Here, we ascertain the epigenetic and genetic modes of bilateral Wilms tumor predisposition.

Pathological and Genetic Stratification for Management of Adrenocortical Carcinoma.

CONTEXT: Adrenocortical carcinoma (ACC) is a rare endocrine malignancy that affects patients across the age spectrum. Although the overall survival in patients with ACC is poor, there is significant heterogeneity in terms of outcomes, presentation, and underlying genetic drivers. EVIDENCE ACQUISITION: This review is based on the evidence collected from primary research studies, expert reviews, and published guidelines. The studies were identified through PubMed search with key words "adrenocortical carcinoma," "prognosis," "pathology," and "genetics." The PubMed search was complemented by authors' expertise, research, and clinical experience in the field of ACC. EVIDENCE SYNTHESIS: Identification of biomarkers has been critical to gain better insight into tumor behavior and to guide therapeutic approach to patients. Tumor stage, resection status, and Ki67 are pathological tumor characteristics that have been identified as prognosticators in patients with ACC. Cortisol excess also correlates with worse prognosis. Clinical and histopathological characteristics help stratify patient outcomes, yet still up to 25% of patients have a different outcome than predicted. To bridge this gap, comprehensive genomic profiling studies have characterized additional profiles that correlate with clinical outcomes. In addition, studies of clinically applicable molecular markers are under way to further stratify outcomes in patients with ACC tumors. CONCLUSIONS: Clinical predictors in combination with pathological markers play a critical role in the approach to patients with ACC. Recent advances in genetic prognosticators will help extend the stratification of these tumors and contribute to a personalized therapeutic approach to patients with ACC.

Paediatric chronic pain prevalence in low- and middle-income countries: A systematic review and meta-analysis.

BACKGROUND: Chronic pain is a leading cause of morbidity in children and adolescents globally, with a significant impact on quality of life. This is the first systematic review and meta-analysis on paediatric chronic pain in low- and middle-income countries (LMICs). METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched MEDLINE (via PubMed), Embase, CINAHL, PsycINFO, Web of Science, Cochrane Database of Systematic Reviews, and the WHO Global Index Medicus for all studies published prior to January 7, 2022. Articles published in all languages that included populations age 19 years and under living in LMICs were considered. Chronic pain was defined as persistent or recurrent pain that is present for ≥3 months, per the International Classification of Diseases (ICD-11) definition. Summary data were extracted from published reports and evaluated with mixed-effects regression analysis. PROSPERO Record ID: CRD42021227967. FINDINGS: Of the 2875 studies identified, 70 articles were reviewed, with 27 studies representing 20 LMICs eligible for analysis. The average prevalence for each pain type reported with 95% confidence interval is as follows: general/multi-site/any 20% (16-25), musculoskeletal (MSK) pain 9% (7-13), abdominal pain 7% (5-10), headache 4% (2-10), and fibromyalgia per American College of Rheumatology or Yunus and Masi criteria 3% (1-10). Overall, a pooled mean of 8% chronic pain was estimated across all studies. A significantly high level of heterogeneity was found across all studies (I2  >90%). Chronic headache (OR=1·65, 95% CI 1·39-1·96), abdominal pain (OR=1·36, 95% CI 1·22-1·51), and generalized/multi-site pain (OR=1·54, 95% CI 1·31-1·81) were significantly more prevalent in females than males. INTERPRETATION: The characterization of paediatric chronic pain in low- and middle-income countries suffers from a paucity of data and significant heterogeneity in the assessment methods. Understanding the global burden of chronic pain in this group should be prioritized. FUNDING: None.

Clinical and Functional Significance of TP53 Exon 4-Intron 4 Splice Junction Variants.

Germline TP53 splicing variants are uncommon, and their clinical relevance is unknown. However, splice-altering variants at exon 4-intron 4 junctions are relatively enriched in pediatric adrenocortical tumors (ACT). Nevertheless, family histories of cancer compatible with classic Li-Fraumeni syndrome are rarely seen in these patients. We used conventional and in silico assays to determine protein stability, splicing, and transcriptional activity of 10 TP53 variants at exon 4-intron 4 junctions and analyzed their clinical correlates. We reviewed public databases that report the impact of TP53 variants in human cancer and examined individual reports, focusing on family history of cancer. TP53 exon 4-intron 4 junction germline variants were identified in 9 of 75 pediatric ACTs enrolled in the International Pediatric Adrenocortical Tumor Registry and Children's Oncology Group ARAR0332 study. An additional eight independent TP53 variants involving exon 4 splicing were identified in the Pediatric Cancer Genome Project (n = 5,213). These variants resulted in improper expression due to ineffective splicing, protein instability, altered subcellular localization, and loss of function. Clinical case review of carriers of TP53 exon 4-intron 4 junction variants revealed a high incidence of pediatric ACTs and atypical tumor types not consistent with classic Li-Fraumeni syndrome. Germline variants involving TP53 exon 4-intron 4 junctions are frequent in ACT and rare in other pediatric tumors. The collective impact of these germline TP53 variants on the fidelity of splicing, protein structure, and function must be considered in evaluating cancer susceptibility. IMPLICATIONS: Taken together, the data indicate that splice variants at TP53 codon 125 and surrounding bases differentially impacted p53 gene expression and function.

TERT Expression in Wilms Tumor Is Regulated by Promoter Mutation or Hypermethylation, WT1, and N-MYC.

Increased TERT mRNA is associated with disease relapse in favorable histology Wilms tumor (WT). This study sought to understand the mechanism of increased TERT expression by determining the association between TERT and WT1 and N-MYC, two proteins important in Wilms tumor pathogenesis that have been shown to regulate TERT expression. Three out of 45 (6.7%) WTs and the corresponding patient-derived xenografts harbored canonical gain-of-function mutations in the TERT promoter. This study identified near ubiquitous hypermethylation of the TERT promoter region in WT compared to normal kidney. WTs with biallelic inactivating mutations in WT1 (7/45, 15.6%) were found to have lower TERT expression by RNA-seq and qRT-PCR and lower telomerase activity determined by the telomerase repeat amplification protocol. Anaplastic histology and increased percentage of blastema were positively correlated with higher TERT expression and telomerase activity. In vitro shRNA knockdown of WT1 resulted in decreased expression of TERT, reduced colony formation, and decreased proliferation of WiT49, an anaplastic WT cell line with wild-type WT1. CRISPR-Cas9-mediated knockout of WT1 resulted in decreased expression of telomere-related gene pathways. However, an inducible Wt1-knockout mouse model showed no relationship between Wt1 knockout and Tert expression in normal murine nephrogenesis, suggesting that WT1 and TERT are coupled in transformed cells but not in normal kidney tissues. N-MYC overexpression resulted in increased TERT promoter activity and TERT transcription. Thus, multiple mechanisms of TERT activation are involved in WT and are associated with anaplastic histology and increased blastema. This study is novel because it identifies potential mechanisms of TERT activation in Wilms tumor that could be of therapeutic interests.