Beyond stiffness: deciphering the role of viscoelasticity in cancer evolution and treatment response.

There is increasing evidence that cancer progression is linked to tissue viscoelasticity, which challenges the commonly accepted notion that stiffness is the main mechanical hallmark of cancer. However, this new insight has not reached widespread clinical use, as most clinical trials focus on the application of tissue elasticity and stiffness in diagnostic, therapeutic, and surgical planning. Therefore, there is a need to advance the fundamental understanding of the effect of viscoelasticity on cancer progression, to develop novel mechanical biomarkers of clinical significance. Tissue viscoelasticity is largely determined by the extracellular matrix (ECM), which can be simulated in vitro using hydrogel-based platforms. Since the mechanical properties of hydrogels can be easily adjusted by changing parameters such as molecular weight and crosslinking type, they provide a platform to systematically study the relationship between ECM viscoelasticity and cancer progression. This review begins with an overview of cancer viscoelasticity, describing how tumor cells interact with biophysical signals in their environment, how they contribute to tumor viscoelasticity, and how this translates into cancer progression. Next, an overview of clinical trials focused on measuring biomechanical properties of tumors is presented, highlighting the biomechanical properties utilized for cancer diagnosis and monitoring. Finally, this review examines the use of biofabricated tumor models for studying the impact of ECM viscoelasticity on cancer behavior and progression and it explores potential avenues for future research on the production of more sophisticated and biomimetic tumor models, as well as their mechanical evaluation.

Somatic mutational profiling and clinical impact of driver genes in Latin-Iberian medulloblastomas: Towards precision medicine.

Medulloblastoma (MB) is the most prevalent malignant brain tumor in children, known for its heterogeneity and treatment-associated toxicity, and there is a critical need for new therapeutic targets. We analyzed the somatic mutation profile of 15 driver genes in 69 Latin-Iberian molecularly characterized medulloblastomas using the Illumina TruSight Tumor 15 panel. We classified the variants based on their clinical impact and oncogenicity. Among the patients, 66.7% were MBSHH, 13.0% MBWNT, 7.3% MBGrp3, and 13.0% MBGrp4. Among the 63 variants found, 54% were classified as Tier I/II and 31.7% as oncogenic/likely oncogenic. We observed 33.3% of cases harboring at least one mutation. TP53 (23.2%, 16/69) was the most mutated gene, followed by PIK3CA (5.8%, 4/69), KIT (4.3%, 3/69), PDGFRA (2.9%, 2/69), EGFR (1.4%, 1/69), ERBB2 (1.4%, 1/69), and NRAS (1.4%, 1/69). Approximately 41% of MBSHH tumors exhibited mutations, TP53 (32.6%) being the most frequently mutated gene. Tier I/II and oncogenic/likely oncogenic TP53 variants were associated with relapse, progression, and lower survival rates. Potentially actionable variants in the PIK3CA and KIT genes were identified. Latin-Iberian medulloblastomas, particularly the MBSHH, exhibit higher mutation frequencies than other populations. We corroborate the TP53 mutation status as an important prognostic factor, while PIK3CA and KIT are potential therapeutic targets.

Epithelial aPKC deficiency leads to stem cell loss preceding metaplasia in colorectal cancer initiation.

The early mechanisms of spontaneous tumor initiation that precede malignancy are largely unknown. We show that reduced aPKC levels correlate with stem cell loss and the induction of revival and metaplastic programs in serrated- and conventional-initiated premalignant lesions, which is perpetuated in colorectal cancers (CRCs). Acute inactivation of PKCλ/ι in vivo and in mouse organoids is sufficient to stimulate JNK in non-transformed intestinal epithelial cells (IECs), which promotes cell death and the rapid loss of the intestinal stem cells (ISCs), including those that are LGR5+. This is followed by the accumulation of revival stem cells (RSCs) at the bottom of the crypt and fetal-metaplastic cells (FMCs) at the top, creating two spatiotemporally distinct cell populations that depend on JNK-induced AP-1 and YAP. These cell lineage changes are maintained during cancer initiation and progression and determine the aggressive phenotype of human CRC, irrespective of their serrated or conventional origin.

Demographics aspects of brain and spine metastatic melanoma. Retrospective analysis in a single third-level center.

Background: Melanoma metastases to the CNS rank third in frequency, just after lung and breast metastases. There is controversy regarding the factors predisposing to developing CNS metastases in patients with cutaneous melanoma and their survival with conventional treatments. Methods: We carried out a retrospective analysis in a third-level hospital in Mexico to determine epidemiological aspects of melanoma metastases to the central nervous system, factors related to its appearance, clinical presentation, and survival in three treatment groups: surgery, radiotherapy, and conservative management. Results: We found that the nodular variant has the most significant association with CNS metastases. In addition, the superficial spreading variant has the highest risk of presenting a more substantial number of lesions, up to seven for each case and predominantly in the infratentorial space. On the other hand, we found more remarkable survival in patients treated only with surgery than those treated with radiotherapy or conservatively. Conclusions: This study lays the foundations for future prospective survival analysis of the different current treatment modalities for metastatic melanoma in the brain and spine. It also highlights the clinical risk factors for metastatic brain and spine tumors of melanoma.

Survival Impact of Combined Biguanide and Temozolomide in Glioblastoma Preclinical Models: A Systematic Review and Meta-Analysis.

BACKGROUND: Glioblastoma (GBM) is an aggressive tumor known for its poor prognosis. Despite extensive research into its molecular and clinical aspects, the current management strategies have shown limited efficacy in improving survival rate. Despite some preclinical studies exploring the combination of temozolomide (TMZ) with biguanides such as metformin (MET) and others, the potential benefits of this combination remain uncertain. The aim of this study is to evaluate the overall survival (OS) in GBM murine-models treated with a combination of TMZ + biguanide compared to those treated with TMZ alone. METHODS: We systematically searched Medline, Embase, and Lilacs databases for studies comparing TMZ + biguanide versus TMZ alone in GBM models and reporting OS data. The mean difference (MD) with 95% confidence interval and random-effects model was adopted. RESULTS: Nine studies were included in this systematic review. The meta-analysis comprised 6 studies involving 85 rat-models, with 45 subjects undergoing combined-treatment. GBM-murine models treated with TMZ + biguanide exhibited notably superior OS rates compared to those who received TMZ alone, showing an MD of 21.0 days (6.9-35.0). Within the subgroup of orthotopic models, the OS was also significantly better in combination-therapy with an MD of 23.7 days (6.5-40.9). Similarly, in the subgroup where MET was used as biguanide therapy, TMZ + MET demonstrated a significant increase in OS, with an MD of 27.4 days (6.0-48.8). In immunocompromised models, the combination-therapy also exhibited higher survival rates, with an MD of 13 days (9.4-16.6). CONCLUSIONS: This systematic review and meta-analysis provide compelling evidence regarding the beneficial effects of TMZ + biguanide in GBM models compared with TMZ alone, resulting in a significant improvement in OS.

Enhanced SREBP2-driven cholesterol biosynthesis by PKCλ/ι deficiency in intestinal epithelial cells promotes aggressive serrated tumorigenesis.

The metabolic and signaling pathways regulating aggressive mesenchymal colorectal cancer (CRC) initiation and progression through the serrated route are largely unknown. Although relatively well characterized as BRAF mutant cancers, their poor response to current targeted therapy, difficult preneoplastic detection, and challenging endoscopic resection make the identification of their metabolic requirements a priority. Here, we demonstrate that the phosphorylation of SCAP by the atypical PKC (aPKC), PKCλ/ι promotes its degradation and inhibits the processing and activation of SREBP2, the master regulator of cholesterol biosynthesis. We show that the upregulation of SREBP2 and cholesterol by reduced aPKC levels is essential for controlling metaplasia and generating the most aggressive cell subpopulation in serrated tumors in mice and humans. Since these alterations are also detected prior to neoplastic transformation, together with the sensitivity of these tumors to cholesterol metabolism inhibitors, our data indicate that targeting cholesterol biosynthesis is a potential mechanism for serrated chemoprevention.

High frequency of WNT-activated medulloblastomas with CTNNB1 wild type suggests a higher proportion of hereditary cases in a Latin-Iberian population.

Purpose: Medulloblastomas are the most common primary malignant brain tumors in children. They are divided into molecular subgroups: WNT-activated, SHH-Activated, TP53 mutant or wild type, and non-WNT/non-SHH (Groups 3 and 4). WNT-activated medulloblastomas are usually caused by mutations in the CTNNB1 gene (85%-90%), and most remaining cases of CTNNB1 wild type are thought to be caused by germline mutations in APC. So far, the frequencies of CTNNB1 have been reported mainly in North American and European populations. The aim of this study was to report the frequency of CTNNB1 mutations in WNT-activated medulloblastomas in a Latin-Iberian population and correlate with their clinicopathological characteristics. Methods: A total of 266 medulloblastomas from seven different institutions from Brazil (n=211), Portugal (n=38), and Argentina (n=17) were evaluated. Following RNA and DNA isolation from formalin-fixed, paraffin-embedded (FFPE) tumor tissues, the molecular classification and CTNNB1 mutation analysis were performed by nCounter and Sanger sequencing, respectively. Results: WNT-activated medulloblastomas accounted for 15% (40/266) of the series. We observed that 73% of WNT-activated medulloblastomas harbored CTNNB1 mutations. CTNNB1 wild-type cases (27%) were more prevalent in female individuals and suggested to be associated with a worse outcome. Among the CTNNB1 wild-type cases, the available analysis of family history revealed two cases with familiar adenomatous polyposis, harboring APC germline variants. Conclusion: We observed a lower incidence of CTNNB1 mutations in WNT-activated medulloblastomas in our Latin-Iberian cohort compared to frequencies previously described in other populations. Considering that CTNNB1 wild-type cases may exhibit APC germline mutations, our study suggests a higher incidence (~30%) of hereditary WNT-activated medulloblastomas in the Latin-Iberian population.

USP15-USP7 Axis and UBE2T Differential Expression May Predict Pathogenesis and Poor Prognosis in De Novo Myelodysplastic Neoplasm.

The aim of this study was to evaluate the expression of USP7, USP15, UBE2O, and UBE2T genes in Myelodysplastic neoplasm (MDS) to identify possible targets of ubiquitination and deubiquitination in MDS pathobiology. To achieve this, eight datasets from the Gene Expression Omnibus (GEO) database were integrated, and the expression relationship of these genes was analyzed in 1092 MDS patients and healthy controls. Our results showed that UBE2O, UBE2T, and USP7 were upregulated in MDS patients compared with healthy individuals, but only in mononucleated cells collected from bone marrow samples (p < 0.001). In contrast, only the USP15 gene showed a downregulated expression compared with healthy individuals (p = 0.03). Additionally, the upregulation of UBE2T expression was identified in MDS patients with chromosomal abnormalities compared with patients with normal karyotypes (p = 0.0321), and the downregulation of UBE2T expression was associated with MDS hypoplastic patients (p = 0.033). Finally, the USP7 and USP15 genes were strongly correlated with MDS (r = 0.82; r2 = 0.67; p < 0.0001). These findings suggest that the differential expression of the USP15-USP7 axis and UBE2T may play an important role in controlling genomic instability and the chromosomal abnormalities that are a striking characteristic of MDS.

Discrepancy in transcriptomic profiling between CD34 + stem cells and primary bone marrow cells in myelodysplastic neoplasm.

Differentially expressed genes (DEGs) biomarkers can be used to help diagnose and monitor the disease, as well as to determine which treatments are most effective. So, given the complexity of Myelodysplastic neoplasm (MDS), it is difficult to determine the impact and disparities of DEGs between CD34+ HSC (hematopoietic stem cells) or primary bone marrow cells (PBMC) in MDS pathogenesis, and therefore it remains largely unknown. Here, we performed an in-silico transcriptome analysis on CD34+ HSC and PBMC from 1092 MDS patients analyzing the divergences between differential gene expression patterns in these two cell types as potential pathogenic biomarkers for MDS. Initially, we observed a difference of 7117 expressed transcripts between PBMC (n = 40,165) and CD34 +HSC (n = 33,048). Also, we identified that CD34+ HSC and PBMC samples showed 240 and 2948 DEGs, respectively. In summary, we identified DEGs disparities in CD34+ HSC and PBMC cell types. However, there was a certain similarity of the activated pathways in both cellular samples based on Gene Ontology and KEGG pathways enrichment analyses. Our results provide novel insights into novel DEGs biomarkers to MDS pathogenesis with clinical significance. AVAILABILITY OF DATA AND MATERIALS: All microarray databases were obtained from Gene Expression Omnibus (https://www.ncbi.nlm.nih.gov/geo/). To evaluate the biological function of differentially expressed genes, the DAVID (Database for Annotation, Visualization and Integrated Discovery tool was used) (https://david.ncifcrf.gov/).

PD-L1 and MCL-1 markers and the relationship with prognostic characteristics of differentiated thyroid carcinoma.

OBJECTIVES: MCL-1 and PD-L1 proteins are related to carcinogenesis mechanisms in differentiated thyroid carcinoma(DTC). Tumor antigens stimulate the expression of PD-1 in immune cells, which binds to PD-L1 of tumor cells, inducing immune escape from the tumor. MCL-1, an anti-apoptotic member of the BCL-2 family, is necessary for the survival of T and B lymphocytes and has a high oncogenic potential. We aim to evaluate the clinical utility and relevance of MCL-1 and PD-L1 in the long-term prognosis of DTC. METHODS: 120 DTC patients after total thyroidectomy and radioiodine therapy followed for a minimum of 2 years were included. Demographic features, tumor histopathology, persistence/recurrence risk, factors associated with outcome, initial response to therapy, persistence or disease-free at the follow-up were related to MCL-1 and PD-L1 immunohistochemical expression and BRAFV600E mutation. RESULTS: 100(83.3%) were women, 46.64 ± 16.73 years old at diagnosis; 37(30.8%) patients were at high, 45(37.5%) of intermediate and 38(31.7%) of low disease recurrence/persistence risk. At the end of follow-up of 124.86 ± 65.36 months, 48(42.5%) had persistent disease. 103(85.8%) patients had papillary thyroid carcinoma (PTC), 17(14.2%) follicular thyroid carcinoma (FTC). In PTC, moderate/strong PD-L1 and MCL-1 expressions were associated to BRAFV600E (p=0.0467; p=0.0044). PD-L1 was also associated with tall cell subtype (p=0.0274). In FTC, weak PD-L1 expression was associated to the largest nodule diameter (p=0.0100). Strong/moderate PD-L1 expression was associated to T2 and the weak expression with T3 in TNM classification (p=0.0490). Moderate MCL-1 expression was associated to smoking (p=0.0350). CONCLUSIONS: PDL-1, marker of progression of tumor cells and MCL-1, anti-apoptotic marker, were associated with PTC carrying BRAFV600E mutation, while PDL-1 was associated with more aggressive PTC subtype. MCL-1 and PD-L1 could be useful in composing a panel to assess the prognosis of PTC patients. On the other hand, both markers seemed to have lower relevance to FTC patients.

Genomic profile of two Brazilian choroid plexus tumors by whole-exome sequencing.

Choroid plexus tumors (CPTs) are rare intracranial neoplasms, representing <1% of all brain tumors, yet they represent 20% of first-year pediatric brain tumors. Although these tumors have been linked to TP53 germline mutations in the context of Li-Fraumeni syndrome, their somatic driver alterations remain poorly understood. In this study, we report two cases of lateral ventricle tumors: 3-yr-old male diagnosed with an atypical choroid plexus papilloma (aCPP), and a 6-mo-old female diagnosed with a choroid plexus carcinoma (CPC). We performed whole-exome sequencing of paired blood and tumor tissue in both patients, categorized somatic variants, and determined copy-number alterations. Our analysis revealed a tier II variant (Association for Molecular Pathology [AMP] criteria) in BRD1, a H3 and TP53 acetylation agent, in the aCPP. In addition, we detected copy-number gains on Chromosomes 12, 18, and 20 and copy-number losses on Chromosomes 13q and 22q (BRD1 locus) in this tumor. The CPC tumor had only a pathogenic germline TP53 variant, based on American College of Medical Genetics (ACMG) criteria, with a clinical and familiar history of Li-Fraumeni syndrome. The CPC patient presented loss of heterozygosity (LoH) of TP53 loci and hyperdiploid genome. Both tumors were microsatellite-stable. This is the first study performing whole-exome sequencing in Brazilian choroid plexus tumors, and in line with the literature, we corroborate the absence of recurrent somatic mutations in these tumors. Further studies with larger sample sizes are necessary to confirm our findings and better understand the underlying biology of these tumors.

Digital expression profile of immune checkpoint genes in medulloblastomas identifies CD24 and CD276 as putative immunotherapy targets.

Introduction: Medulloblastoma is the most common and lethal pediatric malignant brain tumor. It comprises four main molecular subgroups: WNT-activated, SHH-activated, Group 3, and Group 4. Medulloblastoma treatment is surgical resection, craniospinal radiation, and chemotherapy. However, many patients do not respond to therapy, and most suffer severe side effects. Cancer immunotherapy targeting immune checkpoints (IC) (PD-1, PD-L1, and CTLA4) has been getting disappointing outcomes in brain tumors. Nevertheless, other less explored immune checkpoints may be promising candidates for medulloblastoma therapy. Objectives: In the present study, we aimed to characterize the expression profile of 19 immune checkpoints in medulloblastoma. Methods: We analyzed 88 formalin-fixed paraffin-embedded medulloblastomas previously classified for each molecular subgroup and three non-tumoral brain tissue. mRNA levels of 19 immune checkpoint-related genes were quantified using the nCounter (PanCancer Immune Profiling Panel) assay. Further in silico analysis was performed in two larger public microarray datasets, one of which enabled comparisons between tumoral and non-tumoral tissues. Immunohistochemistry of PD-L1 was performed in a subset of cases. Microsatellite instability was also molecularly analyzed. Results: We observed an absence of expression of the canonic ICs, namely PDCD1 (PD-1), CD274 (PD-L1), and CTLA4, as well as CD80, CD86, BTLA, IDO1, CD48, TNFSF14, CD160, CEACAM1, and CD244. PD-L1 protein expression was also practically absent. We found higher mRNA levels of CD24, CD47, CD276 (B7-H3), and PVR, and lower mRNA levels of HAVCR2, LAG3, and TIGIT genes, with significant differences across the four molecular subgroups. Compared to the non-tumor tissues, the expression levels of CD276 in all subgroups and CD24 in SHH, Group 3, and Group 4 subgroups are significantly higher. The in silico analysis confirmed the expression profile found in the Brazilian cohort, including the lower/absent expression of the canonic ICs. Moreover, it confirmed the overexpression of CD24 and CD276 in medulloblastomas compared with the non-tumor tissue. Additionally, CD276 and CD24 high levels were associated with worse survival. Conclusion: These results highlight the low or absence of mRNA levels of the canonic targetable ICs in medulloblastomas. Importantly, the analysis revealed overexpression of CD24 and CD276, which can constitute prognostic biomarkers and attractive immunotherapy targets for medulloblastomas.

Dual Microscope Indocyanine Green Video Angiography and Endoscopic Review to Treat Intracranial Aneurysm: A Review of the Literature Regarding a Case.

The use of the indocyanine green video angiography (ICG-VA) both endoscope and microscope has become popular in recent decades thanks to the safety, efficacy, and added value that they have provided for cerebrovascular surgery. The dual use of these technologies is considered complementary and has helped cerebrovascular surgeons in decision-making, especially for aneurysm clipping surgery; however, its use has been described for both aneurysm surgery, resection of arteriovenous malformations, or even for bypass surgeries. We conducted a review of the literature with the MeSH terms "microscope indocyanine green video angiography (mICG-VA)," "endoscopic review," AND/OR "intracranial aneurysm." A total of 97 articles that included these terms were selected after a primary review to select a total of 26 articles for the final review. We also present a case to exemplify its use, in which we use both technological tools for the description of the aneurysm, as well as for decision-making at the time of clipping and for reclipping. Both tools, both the use of the endoscope and the mICG-VA, have helped decision-making in neurovascular surgery. A considerable clip replacement rate has been described with the use of these technologies, which has helped to reduce the complications associated with poor clipping. One of the main advantages of their usefulness is that they are tools for intraoperative use, which is why they have shown superiority compared to digital subtraction angiography, which takes longer to use and has a higher risk of complications associated with the contrast medium. On the other hand, a very low rate of complications has been described with the use of the endoscope and mICG-VA, which is why they are considered safe tools to use. In some cases, mention has been made of the use of one or the other technology; however, we consider that its dual use provides more information about the status of the clip, its anatomy, its relationship with other vascular structures, and the complete occlusion of the aneurysm. We consider that the use of both technologies is complementary, so in case of having them both should be used, since both the endoscope and the mICG-VA provide additional and useful information.

Cancer immune profiling unveils biomarkers, immunological pathways, and cell type score associated with glioblastoma patients' survival.

Introduction: Glioblastoma (GBM), isocitrate dehydrogenase (IDH) wild-type (IDH wt), and grade 4 astrocytomas, IDH mutant (IDH mut), are the most common and aggressive primary malignant brain tumors in adults. A better understanding of the tumor immune microenvironment may provide new biomarkers and therapeutic opportunities. Objectives: We aimed to evaluate the expression profile of 730 immuno-oncology-related genes in patients with IDH wt GBM and IDH mut tumors and identify prognostic biomarkers and a gene signature associated with patient survival. Methods: RNA was isolated from formalin-fixed, paraffin-embedded sections of 99 tumor specimens from patients treated with standard therapy. Gene expression profile was assessed using the Pan-Cancer Immune Profiling Panel (Nanostring Technologies, Inc., Seattle, WA, USA). Data analysis was performed using nSolverSoftware and validated in The Cancer Genome Atlas. In addition, we developed a prognostic signature using the cox regression algorithm (Least Absolute Shrinkage and Selection Operator). Results: We found 88 upregulated genes, high immunological functions, and a high macrophage score in IDH wt GBM compared to IDH mut tumors. Regarding IDH wt GBM, we found 24 upregulated genes in short-term survivors (STS) and overexpression of CD274 (programmed death-ligand 1, PD-L1). Immune pathways, CD45, cytotoxic, and macrophage scores were upregulated in STS. Two different prognostic groups were found based on the 12-gene signature (CXCL14, PSEN2, TNFRSF13C, IL13RA1, MAP2K1, TNFSF14, THY1, CTSL, ITGAE, CHUK, CD207, and IFITM1). Conclusion: The elevated expression of immune-oncology-related genes was associated with worse outcome in IDH wt GBM patients. Increased immune functions, CD45, cytotoxic cells, and macrophage scores were associated with a more aggressive phenotype and may provide promising possibilities for therapy. Moreover, a 12 gene-based signature could predict patients' prognosis.

Role of Sirtuins in the Pathobiology of Onco-Hematological Diseases: A PROSPERO-Registered Study and In Silico Analysis.

The sirtuins (SIRT) gene family (SIRT1 to SIRT7) contains the targets implicated in cellular and organismal aging. The role of SIRTs expression in the pathogenesis and overall survival of patients diagnosed with solid tumors has been widely discussed. However, studies that seek to explain the role of these pathways in the hematopoietic aging process and the consequences of their instability in the pathogenesis of different onco-hematological diseases are still scarce. Therefore, we performed a systematic review (registered in PROSPERO database #CRD42022310079) and in silico analysis (based on GEPIA database) to discuss the role of SIRTs in the advancement of pathogenesis and/or prognosis for different hematological cancer types. In summary, given recent available scientific evidence and in silico gene expression analysis that supports the role of SIRTs in pathobiology of hematological malignances, such as leukemias, lymphomas and myeloma, it is clear the need for further high-quality research and clinical trials that expands the SIRT inhibition knowledge and its effect on controlling clonal progression caused by genomic instability characteristics of these diseases. Finally, SIRTs represent potential molecular targets in the control of the effects caused by aging on the failures of the hematopoietic system that can lead to the involvement of hematological neoplasms.

Comparison of five methods for locked-plate fixation of complex diaphyseal fractures.

BACKGROUND: Peri-prosthetic fractures (PPFs) are steadily rising in number due to population ageing and increased performance of joint replacement procedures. Although PPFs without implant loosening are usually managed by internal fixation, no consensus exists regarding the optimal construct. The primary objective of this study was to compare five constructs, and the secondary objective was to compare sub-groups of mono-cortical screw constructs, with the goal of identifying the method most appropriate for diaphyseal fracture fixation when prosthetic material is present within the intra-medullary canal. HYPOTHESIS: The primary hypothesis was that fixation using bi-cortical screws, i.e., the current reference standard, was superior over other fixation methods. The secondary hypothesis was that adding double cerclage to mono-cortical screw fixation provided the greatest mechanical strength. MATERIALS AND METHODS: Synthetic osteoporotic bone was used to compare five methods for locking-screw fixation of a femoral diaphyseal plate. One method involved bi-cortical screws and four methods mono-cortical screws, with no cerclage wire, a single cerclage wire on either side positioned near or at a distance from the fracture, and two cerclage wires on both sides of the fracture. A complex fracture was simulated by creating a 2-cm diaphyseal gap. Load-to-failure was determined by applying compression loading along the anatomical axis of the femur. RESULTS: Bi-cortical screw fixation provided greater mechanical strength than did three of the four mono-cortical screw constructs. The exception was the mono-cortical-screw and double-cerclage construct, for which no significant difference was found compared to bi-cortical screw fixation. Thus, mono-cortical screw fixation with double cerclage may be the best alternative when presence of an implant in the intra-medullary canal precludes bi-cortical screw fixation. CONCLUSION: The findings from this study have clear implications for clinical practice. The study hypotheses were partly confirmed. The absence of a significant difference between the reference-standard bi-cortical screw fixation method and mono-cortical screw fixation with double cerclage, combined with the results regarding the secondary objective, suggest that mono-cortical screws plus double cerclage deserve preference in patients with an intra-medullary implant. Clinical studies are needed to assess the results of this bench study. LEVEL OF EVIDENCE: IV, bench study.

Panobinostat (LBH589) increase survival in adult xenografic model of acute lymphoblastic leukemia with t(4;11) but promotes antagonistic effects in combination with MTX and 6MP.

Patients diagnosed with acute lymphoblastic leukemia (ALL) bearing t(4;11)/MLL-AF4 have aggressive clinical features, poor prognosis and there is an urgent need for new therapies to improve outcomes. Panobinostat (LBH589) has been identified as a potential therapeutic agent for ALL with t(4;11) and studies suggest that the antineoplastic effects are associated with reduced MLL-AF4 fusion protein and reduced expression of HOX genes. Here, we evaluated the in vitro effects of the combination of LBH589 with methotrexate (MTX) or 6-mercaptopurine (6MP) by cell proliferation assays and Calcusyn software in ALL cell line (RS4;11); the in vivo effects of LBH589 in xenotransplanted NOD-scid IL2Rgammanull mice measuring human lymphoblasts by flow cytometry; and the expression of HOX genes by qPCR after treatment in an adult model of ALL with t(4;11). LBH589 combination with MTX or 6MP did not promote synergistic effects in RS4;11 cell line. LBH589 treatment leads to increased overall survival and reduction of blasts in xenotransplanted mice but caused no significant changes in HOXA7, HOXA9, HOXA10, and MEIS1 expression. The LBH589, alone, showed promising antineoplastic effects in vivo and may represent a potential agent for chemotherapy in ALL patients with t(4;11).

Role of Polygenic Risk Score in Cancer Precision Medicine of Non-European Populations: A Systematic Review.

The development of new screening methods and diagnostic tests for traits, common diseases, and cancer is linked to the advent of precision genomic medicine, in which health care is individually adjusted based on a person's lifestyle, environmental influences, and genetic variants. Based on genome-wide association study (GWAS) analysis, rapid and continuing progress in the discovery of relevant single nucleotide polymorphisms (SNPs) for traits or complex diseases has increased interest in the potential application of genetic risk models for routine health practice. The polygenic risk score (PRS) estimates an individual's genetic risk of a trait or disease, calculated by employing a weighted sum of allele counts combined with non-genetic variables. However, 98.38% of PRS records held in public databases relate to the European population. Therefore, PRSs for multiethnic populations are urgently needed. We performed a systematic review to discuss the role of polygenic risk scores in advancing precision medicine for different cancer types in multiethnic non-European populations.

High value of 64Cu as a tool to evaluate the restoration of physiological copper excretion after gene therapy in Wilson's disease.

Wilson's disease (WD) is an inherited disorder of copper metabolism associated with mutations in ATP7B gene. We have shown that the administration of an adeno-associated vector (AAV) encoding a mini version of human ATP7B (VTX-801) provides long-term correction of copper metabolism in a murine WD model. In preparation of a future clinical trial, we have evaluated by positron emission tomography (PET) the value of 64Cu biodistribution, excretion pattern, and blood kinetics as pharmacodynamic biomarkers of VTX-801 effects. Six-week-old WD mice were injected intravenously with increasing doses of VTX-801 and 3 weeks or 3 months later with [64Cu]CuCl2. Untreated WD and wild-type (WT) mice were included as controls. Control WD mice showed increased hepatic 64Cu retention, reduced fecal excretion of the radiotracer, and altered 64Cu blood kinetics (BK) compared with WT mice. VTX-801 treatment in WD mice resulted in a significant reduction of hepatic 64Cu accumulation, the restoration of fecal 64Cu excretion, and the correction of 64Cu BK. This study showed that VTX-801 restores physiological copper metabolism in WD mice, confirming the mechanism of action of VTX-801, and demonstrated the translational potential of [64Cu]CuCl2-PET to explore VTX-801 pharmacodynamics in a minimally invasive and sensitive manner in WD patients.

NTRK2 gene fusions are uncommon in pilocytic astrocytoma.

BACKGROUND: Pilocytic astrocytoma is the most frequent pediatric glioma. Despite its overall good prognosis, complete surgical resection is sometimes unfeasible, especially for patients with deep-seated tumors. For these patients, the identification of targetable genetic alterations such as NTRK fusions, raised as a new hope for therapy. The presence of gene fusions involving NTRK2 has been rarely reported in pilocytic astrocytoma. The aim of the present study was to investigate the frequency of NTRK2 alterations in a series of Brazilian pilocytic astrocytomas. METHODS: Sixty-nine pilocytic astrocytomas, previously characterized for BRAF and FGFR1 alterations were evaluated. The analysis of NTRK2 alterations was performed using a dual color break apart fluorescence in situ hybridization (FISH) assay. RESULTS: NTRK2 fusions were successfully evaluated by FISH in 62 of the 69 cases. Neither evidence of NTRK2 gene rearrangements nor NTRK2 copy number alterations were found. CONCLUSIONS: NTRK2 alterations are uncommon genetic events in pilocytic astrocytomas, regardless of patients' clinicopathological and molecular features.