Search

Gliomas are characterised by local infiltration, migration of tumour cells across long distances and sustained angiogenesis; therefore, proteins involved in these processes are most likely important. Such candidates are semaphorins involved in axon guidance and cell migration. In addition, semaphorins regulate tumour progression and angiogenesis. For cell signalling, class-4 semaphorins bind directly to plexins, whereas class-3 semaphorins require additional neuropilin (NRP) receptors that also bind VEGF(165). The anti-angiogenic activity of class-3 semaphorins can be explained by competition with VEGF(165) for NRP binding. In this study, we analysed the expressions of seven semaphorins of class-3, SEMA4D, VEGF and the NRP1 and NRP2 receptors in 38 adult glial tumours. In these tumours, SEMA3B, SEMA3G and NRP2 expressions were related to prolonged survival. In addition, SEMA3D expression was reduced in high-grade as compared with low-grade gliomas. In contrast, VEGF correlated with higher grade and poor survival. Thus, our data suggest a function for a subset of class-3 semaphorins as inhibitors of tumour progression, and the prognostic value of the VEGF/SEMA3 balance in adult gliomas. Moreover, in multivariate analysis, SEMA3G was found to be the only significant prognostic marker. [ABSTRACT FROM AUTHOR]

This study assessed the prognostic value of several markers involved in gliomagenesis, and compared it with that of other clinical and imaging markers already used. Four-hundred and sixteen adult patients with newly diagnosed glioma were included over a 3-year period and tumour suppressor genes, oncogenes, MGMT and hTERT expressions, losses of heterozygosity, as well as relevant clinical and imaging information were recorded. This prospective study was based on all adult gliomas. Analyses were performed on patient groups selected according to World Health Organization histoprognostic criteria and on the entire cohort. The endpoint was overall survival, estimated by the Kaplan-Meier method. Univariate analysis was followed by multivariate analysis according to a Cox model. p14(ARF), p16(INK4A) and PTEN expressions, and 10p 10q23, 10q26 and 13q LOH for the entire cohort, hTERT expression for high-grade tumours, EGFR for glioblastomas, 10q26 LOH for grade III tumours and anaplastic oligodendrogliomas were found to be correlated with overall survival on univariate analysis and age and grade on multivariate analysis only. This study confirms the prognostic value of several markers. However, the scattering of the values explained by tumour heterogeneity prevents their use in individual decision-making. [ABSTRACT FROM AUTHOR]

CDKN2A locus on chromosome 9p21 encodes two tumour suppressor proteins pl6INK4A, which is a regulator of the retinoblastoma (RB) protein, and p14ARF, which is involved in the ARF-Mdm2-p53 pathway. The aim of this study was to determine if CDKN2A gene products are implicated in differentiated thyroid carcinogenesis and progression. We used real-time quantitative RT-PCR and immunohistochemistry to assess both transcripts and proteins levels in 60 tumours specimens. Overexpression of p14ARF and pl6INK4A was observed in follicular adenomas, follicular carcinomas and papillary carcinomas, while downregulation was found in oncocytic adenomas compared to nontumoral paired thyroid tissues. These deregulations were statistically significant for pl6INK4a (P=0.006) in follicular adenomas and close to statistical significance for p14ARF in follicular adenomas (P=0.06) and in papillary carcinomas (P=0.05). In all histological types, except papillary carcinomas, we observed a statistically significant relationship between p14ARF and E2F1 (r=0.64 to 1, P<0.05). Our data are consistent with involvement of CDKN2A transcript upregulation in thyroid follicular tumorigenesis as an early event. However, these deregulations do not appear to be correlated to the clinical outcome and they could not be used as potential prognostic markers. [ABSTRACT FROM AUTHOR]

Glial tumours are a devastating, poorly understood condition carrying a gloomy prognosis for which clinicians sorely lack reliable predictive parameters facilitating a sound treatment strategy. Tp73, a p53 family member, expresses two main classes of isoforms--transactivatory activity (TA)p73 and DeltaTAp73--exhibiting tumour suppressor gene and oncogene properties, respectively. The authors examined their expression status in high- and low-grade adult gliomas. Isoform-specific real-time reverse transcription-polymerase chain reaction was used for the analysis of Tp73 isoform transcript expression in a series of 51 adult patients harbouring glial tumours, in order to compare tumour grades with each other, and with non-tumoural samples obtained from epileptic patients as well. Our data demonstrate increase of TAp73 and DeltaTAp73 transcript levels at onset and early stage of the disease. We also show that DeltaEx2-3 isoform expression in low-grade tumours anticipates clinical and imaging progression to higher grades, and correlates to the patients' survival. Expression levels of P1 promoter generated Tp73 isoforms--and particularly DeltaEx2-3--indeed allow for prediction of the clinical progression of low-grade gliomas in adults. Our data are the first such molecular biology report regarding low-grade tumours and as such should be of help for sound decision-making. [ABSTRACT FROM AUTHOR]

Abstract Background The molecular characteristics associated with the response to treatment in glioblastomas (GBMs) remain largely unknown. We performed a retrospective study to assess the genomic characteristics associated with the response of GBMs to either first-line chemotherapy or radiation therapy. The gene expression (n = 56) and genomic profiles (n = 67) of responders and non-responders to first-line chemotherapy or radiation therapy alone were compared on Affymetrix Plus 2 gene expression arrays and BAC CGH arrays. Results According to Verhaak et al.'s classification system, mesenchymal GBMs were more likely to respond to radiotherapy than to first-line chemotherapy, whereas classical GBMs were more likely to respond to first-line chemotherapy than to radiotherapy. In patients treated with radiation therapy alone, the response was associated with differential expression of microenvironment-associated genes; the expression of hypoxia-related genes was associated with short-term progression-free survival (< 5 months), whereas the expression of immune genes was associated with prolonged progression-free survival (> 10 months). Consistently, infiltration of the tumor by both CD3 and CD68 cells was significantly more frequent in responders to radiotherapy than in non-responders. In patients treated with first-line chemotherapy, the expression of stem-cell genes was associated with resistance to chemotherapy, and there was a significant association between response to treatment and p16 locus deletions. Consistently, in an independent data set of patients treated with either radiotherapy alone or with both radiotherapy and adjuvant chemotherapy, we found that patients with the p16 deletion benefited from adjuvant chemotherapy regardless of their MGMT promoter methylation status, whereas in patients without the p16 deletion, this benefit was only observed in patients with a methylated MGMT promoter. Conclusion Differential expression of microenvironment genes and p16 locus deletion are associated with responses to radiation therapy and to first-line chemotherapy, respectively, in GBM. Recently identified transcriptomic subgroups of GBMs seem to respond differently to radiotherapy and to first-line chemotherapy.

• Phase 1 trial of concomitant ralimetinib with radiotherapy (and TMZ) in glioblastoma patients. • First worldwide phase 1 trial to evaluate the combination of a p38-MAPK inhibitor (ralimetinib) with radiotherapy. • The recommended dose of ralimetinib was 100 mg/12 h with chemoradiotherapy. • At recommended dose, potentially ralimetinib-related toxicity included grade 3 hepatic cytolysis (13%) and rash (7%). This phase 1 trial aimed to determine the maximum tolerated dose (MTD; primary objective) of a p38-MAPK inhibitor, ralimetinib, with radiotherapy (RT) and chemotherapy (TMZ), in the treatment of newly diagnosed glioblastoma (GBM) patients. The study was designed as an open-label dose-escalation study driven by a Tite-CRM design and followed by an expansion cohort. Ralimetinib was administered orally every 12 h, 7 days a week, for 2 cycles of 2 weeks at a dose of 100, 200 or 300 mg/12 h. Patients received ralimetinib added to standard concurrent RT (60 Gy in 30 fractions) with TMZ (75 mg/m2/day) and 6 cycles of adjuvant TMZ (150–200 mg/m2 on days 1–5 every 28 days). The MTD of ralimetinib was 100 mg/12 h with chemoradiotherapy. The three patients treated at 200 mg/12 h presented a dose-limiting toxicity: one patient had a grade 3 face edema, and two patients had a grade 3 rash and grade 3 hepatic cytolysis (66%). Of the 18 enrolled patients, 15 received the MTD of ralimetinib. At the MTD, the grade ≥ 3 adverse events during concomitant chemoradiotherapy were hepatic cytolysis (2/15 patients), dermatitis/rash (1/15), lymphopenia (1/15) and nausea/vomiting (1/15). No interaction of TMZ and ralimetinib when administrated concomitantly has been observed. Inhibition of pMAPKAP-K2 (−54%) was observed in peripheral blood mononuclear cells. This phase 1 trial is the first trial to study the combination of a p38-MAPK inhibitor, ralimetinib, with radiotherapy (RT) and chemotherapy (TMZ), in the treatment of newly diagnosed glioblastoma (GBM) patients. The MTD of ralimetinib was 100 mg/12 h. The most frequent dose-limiting toxicities were hepatic cytolysis and rash. [ABSTRACT FROM AUTHOR]

Background A microsatellite instability (MSI) phenotype is found in about 12% of colorectal cancers (CRCs) and is associated with a low recurrence rate after curative surgery. Several studies have identified clinical and pathological factors predictive of recurrence in resected CRC, but not in the MSI subgroup. Patients and methods This multicentre retrospective study included patients with stage I, II or III MSI CRCs. Disease-free survival (DFS) was calculated with the Kaplan–Meier method. Factors associated with DFS were identified in univariate and multivariate Cox analyses. Results We studied 521 patients with MSI CRC. Respectively 11%, 51% and 38% of patients were at stage I, II and III. Mean age was 68.7 years and 36% of the patients received adjuvant chemotherapy. Median follow-up was 32.8 months. The disease recurrence rates were 6% and 21% in stage II and III patients, respectively. The 3-year DFS rate was 77%. In univariate analysis, age, bowel obstruction, lymph node invasion, stage T4, vascular emboli, lymphatic invasion and perinervous invasion were associated with poorer DFS ( P < 0.05). Three relevant independent predictors of poor DFS were identified in multivariate analysis, namely bowel obstruction (HR = 2.46; 95%CI 1.31–4.62, P = 0.005), vascular emboli (HR = 2.79; 95%CI 1.74–4.47, P < 0.001) and stage T4 (HR = 2.16; 95%CI 1.31–3.56, P = 0.002). Conclusions Bowel obstruction, vascular emboli and stage T4 are independently associated with MSI CRC recurrence, suggesting that screening for vascular emboli in routine clinical practice may assist with adjuvant chemotherapy decision-making. [ABSTRACT FROM AUTHOR]

Glioblastoma (GBM) is a highly lethal type of cancer. GBM recurrence following chemoradiation is typically attributed to the regrowth of invasive and resistant cells. Therefore, there is a pressing need to gain a deeper understanding of the mechanisms underlying GBM resistance to chemoradiation and its ability to infiltrate. Using a combination of transcriptomic, proteomic, and phosphoproteomic analyses, longitudinal imaging, organotypic cultures, functional assays, animal studies, and clinical data analyses, we demonstrate that chemoradiation and brain vasculature induce cell transition to a functional state named VC-Resist (vessel co-opting and resistant cell state). This cell state is midway along the transcriptomic axis between proneural and mesenchymal GBM cells and is closer to the AC/MES1-like state. VC-Resist GBM cells are highly vessel co-opting, allowing significant infiltration into the surrounding brain tissue and homing to the perivascular niche, which in turn induces even more VC-Resist transition. The molecular and functional characteristics of this FGFR1-YAP1-dependent GBM cell state, including resistance to DNA damage, enrichment in the G2M phase, and induction of senescence/stemness pathways, contribute to its enhanced resistance to chemoradiation. These findings demonstrate how vessel co-option, perivascular niche, and GBM cell plasticity jointly drive resistance to therapy during GBM recurrence., (© 2024. The Author(s).)

Protein S (PROS1) is a vitamin K-dependent anticoagulant factor, which also acts as an agonist for the TYRO3, AXL, and MERTK (TAM) tyrosine kinase receptors. PROS1 is produced by the endothelium which also expresses TAM receptors, but little is known about its effects on vascular function and permeability. Transwell permeability assays as well as Western blotting and immunostaining analysis were used to monitor the possible effects of PROS1 on both endothelial cell permeability and on the phosphorylation state of specific signaling proteins. We show that human PROS1, at its circulating concentrations, substantially increases both the basal and VEGFA-induced permeability of endothelial cell (EC) monolayers. PROS1 induces p38 MAPK (Mitogen Activated Protein Kinase), Rho/ROCK (Rho-associated protein kinase) pathway activation, and actin filament remodeling, as well as substantial changes in Vascular Endothelial Cadherin (VEC) distribution and its phosphorylation on Ser 665 and Tyr 685 . It also mediates c-Src and PAK-1 (p21-activated kinase 1) phosphorylation on Tyr 416 and Ser 144 , respectively. Exposure of EC to human PROS1 induces VEC internalization as well as its cleavage into a released fragment of 100 kDa and an intracellular fragment of 35 kDa. Using anti-TAM neutralizing antibodies, we demonstrate that PROS1-induced VEC and c-Src phosphorylation are mediated by both the MERTK and TYRO3 receptors but do not involve the AXL receptor. MERTK and TYRO3 receptors are also responsible for mediating PROS1-induced MLC (Myosin Light Chain) phosphorylation on a site targeted by the Rho/ROCK pathway. Our report provides evidence for the activation of the c-Src/VEC and Rho/ROCK/MLC pathways by PROS1 for the first time and points to a new role for PROS1 as an endogenous vascular permeabilizing factor., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

The detection of microsatellite instability (MSI) and mismatch repair (MMR) deficiency has become mandatory for most tumors in recent years, owing to the development of immune checkpoint inhibitors as a highly effective therapy for MMR deficiency/MSI tumors. The timely and efficient detection of MSI is valuable, and new methods are increasingly being developed. To date, MMR assessment has been performed using immunohistochemistry of the 4 MMR proteins and/or microsatellite stability/MSI using PCR, mostly using the pentaplex panel. The implementation of next-generation sequencing (NGS) for MSI analysis would improve the effectiveness at a lower cost and in less time. This study describes the development of 8 new microsatellites combined with a classification algorithm, termed "Octaplex CaBio-MSID" (for Cancérologie Biologique MSI Detection tool), to assess MSI using NGS. A series of 303 colorectal cancer and 88 endometrial cancer samples were assessed via MSI testing using NGS using the Octaplex CaBio-MSID algorithm. The sensitivity and specificity of Octaplex CaBio-MSID were 98.4% and 98.4% for colorectal cancers, and 89.3% and 100% for endometrial cancers, respectively. This new NGS-based MSI detection method outperforms previously published methods (ie, Idylla [Biocartis], OncoMate MSI Dx [Promega], and Foundation One CDx [Roche Foundation Medicine]). Although highly efficient, Octaplex CaBio-MSID requires validation in a larger independent series of different tumor types., (Copyright © 2023. Published by Elsevier Inc.)

The bevacizumab (bev)/olaparib (ola) maintenance regimen was approved for BRCA1/2-mutated (BRCAmut) and Homologous Recombination Deficient (HRD) high-grade Advanced Ovarian Cancer (AOC) first line setting, based on a significantly improved progression-free survival (PFS) compared to bev alone in the PAOLA-1/ENGOT-ov25 trial (NCT02477644), where HRD was detected by MyChoice CDx PLUS test. The academic shallowHRDv2 test was developed based on shallow whole-genome sequencing as an alternative to MyChoice. Analytical and clinical validities of shallowHRDv2 as compared to MyChoice on 449 PAOLA-1 tumor samples are presented. The overall agreement between shallowHRDv2 and MyChoice was 94% (369/394). Less non-contributive tests were observed with shallowHRDv2 (15/449; 3%) than with MyChoice (51/449; 11%). Patients with HRD tumors according to shallowHRDv2 (including BRCAmut) showed a significantly prolonged PFS with bev+ola versus bev (median PFS: 65.7 versus 20.3 months, hazard ratio (HR): 0.36 [95% CI: 0.24-0.53]). This benefit was significant also for BRCA1/2 wild-type tumors (40.8 versus 19.5 months, HR: 0.45 [95% CI: 0.26-0.76]). ShallowHRDv2 is a performant, clinically validated, and cost-effective test for HRD detection., (© 2023. The Author(s).)

Background: There is no robust predictor of response to chemotherapy (CT) in unresectable pancreatic adenocarcinomas (UPA). The objective of the KRASCIPANC study was to analyze the kinetics of cell-free DNA (cfDNA)/circulating tumor DNA (ctDNA) as a predictor of response to CT in UPA., Methods: Blood samples were collected just before first CT and at day 28. The primary endpoint was the kinetics of KRAS-mutated ctDNA by digital droplet PCR between D0 and D28 as a predictor of progression-free survival (PFS)., Results: We analyzed 65 patients with a KRAS-mutated tumor. A high level of cfDNA and KRAS-mutated ctDNA at D0, as well as the presence of KRAS-mutated ctDNA at D28, were strongly associated with lower centralized disease control rate (cDCR), shorter cPFS and OS in multivariate analysis. A score combining cfDNA level at diagnosis ≥ or <30 ng/mL and presence or not of KRAS-mutated ctDNA at D28 was an optimal predictor of cDCR (OR=30.7, IC95% 4.31-218 P=.001), PFS (HR=6.79, IC95% 2.76-16.7, P<.001) and OS (HR=9.98, IC95% 4.14-24.1, P<.001)., Conclusion: A combined score using cfDNA level at diagnosis and KRAS-mutated ctDNA at D28 is strongly associated with patient survival/response to chemotherapy in UPA., Trial Registration: ClinicalTrials.gov Identifier: NCT04560270., Competing Interests: Conflict of Interest The authors declare that they have no conflict of interest., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Purpose: The immune microenvironment of sebaceous neoplasms (SNs) has been poorly explored, especially in benign lesions, and never correlated to the mismatch repair (MMR) status., Methods: We conducted an immuno-histological study to analyze the immune microenvironment of SNs. A tissue microarray was constructed including sebaceous adenomas (SAs), sebaceomas (Ss) and sebaceous carcinomas (SCs) to performed immuno-histological analysis of T cells, B cells, macrophages, dendritic cells, and expression of Programmed Death-1 (PD-1) and Programmed Death Ligand 1 (PD-L1). An automatized count was performed using the QuPath® software. Composition of the cellular microenvironment was compared to the aggressiveness, the MMR status, and to Muir-Torre syndrome (MTS)., Results: We included 123 SNs (43 SAs, 19 Ss and 61 SCs) for which 71.5% had a dMMR phenotype. A higher infiltration of macrophages (CD68 +) of M2 phenotype (CD163 +) and dendritic cells (CD11c +) was noticed in SCs compared to benign SNs (SAs and Ss). Programmed cell death ligand-1 but not PD-1 was expressed by more immune cells in SCs compared to benign SNs. No difference in the immune cell composition regarding the MMR status, or to MTS was observed., Conclusion: In SNs, M2 macrophages and dendritic cells infiltrates are associated with the progression and the malignant transformation of tumors. High PD-L1 expression in immune cells in SCs is an argument for the use of immunotherapy by anti-PD1 or PD-L1 in metastatic patients. The lack of correlation between the composition of immune cells in SNs and the MMR status emphasizes the singularity of SNs among MMR-associated malignancies., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Gliomas are the most common and lethal primary brain tumors in adults. Glioblastomas, the most frequent and aggressive form of gliomas, represent a therapeutic challenge as no curative treatment exists to date, and the prognosis remains extremely poor. Recently, the transcriptional cofactors Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) belonging to the Hippo pathway have emerged as a major determinant of malignancy in solid tumors, including gliomas. However, the mechanisms involved in its regulation, particularly in brain tumors, remain ill-defined. In glioblastomas, EGFR represents one of the most altered oncogenes affected by chromosomal rearrangements, mutations, amplifications, and overexpression. In this study, we investigated the potential link between epidermal growth factor receptor (EGFR) and the transcriptional cofactors YAP and TAZ by in situ and in vitro approaches. We first studied their activation on tissue microarray, including 137 patients from different glioma molecular subtypes. We observed that YAP and TAZ nuclear location was highly associated with isocitrate dehydrogenase 1/2 (IDH1/2) wild-type glioblastomas and poor patient outcomes. Interestingly, we found an association between EGFR activation and YAP nuclear location in glioblastoma clinical samples, suggesting a link between these 2 markers contrary to its ortholog TAZ. We tested this hypothesis in patient-derived glioblastoma cultures by pharmacologic inhibition of EGFR using gefinitib. We showed an increase of S397-YAP phosphorylation associated with decreased AKT phosphorylation after EGFR inhibition in phosphatase and tensin homolog (PTEN) wild-type cultures, unlike PTEN-mutated cell lines. Finally, we used bpV(HOpic), a potent PTEN inhibitor, to mimic the effect of PTEN mutations. We found that the inhibition of PTEN was sufficient to revert back the effect induced by Gefitinib in PTEN-wild-type cultures. Altogether, to our knowledge, these results show for the first time the regulation of pS397-YAP by the EGFR-AKT axis in a PTEN-dependent manner., (Copyright © 2022 United States & Canadian Academy of Pathology. Published by Elsevier Inc. All rights reserved.)

Background & Aims: Brain metastases (BMs) from colorectal cancer (CRC) are associated with significant morbidity and mortality, with chemoresistance and short overall survival. Migrating cancer stem cells with the ability to initiate BM have been described in breast and lung cancers. In this study, we describe the identification and characterization of cancer stem cells in BM from CRC., Methods: Four brain metastasis stem cell lines from patients with colorectal cancer (BM-SC-CRC1 to BM-SC-CRC4) were obtained by mechanical dissociation of patient's tumors and selection of cancer stem cells by appropriate culture conditions. BM-SC-CRCs were characterized in vitro by clonogenic and limiting-dilution assays, as well as immunofluorescence and Western blot analyses. In ovo, a chicken chorioallantoic membrane (CAM) model and in vivo, xenograft experiments using BALB/c-nude mice were realized. Finally, a whole exome and RNA sequencing analyses were performed., Results: BM-SC-CRC formed metaspheres and contained tumor-initiating cells with self-renewal properties. They expressed stem cell surface markers (CD44v6, CD44, and EpCAM) in serum-free medium and CRC markers (CK19, CK20 and CDX-2) in fetal bovine serum-enriched medium. The CAM model demonstrated their invasive and migratory capabilities. Moreover, mice intracranial xenotransplantation of BM-SC-CRCs adequately recapitulated the original patient BM phenotype. Finally, transcriptomic and genomic approaches showed a significant enrichment of invasiveness and specific stemness signatures and highlighted KMT2C as a potential candidate gene to potentially identify high-risk CRC patients., Conclusions: This original study represents the first step in CRC BM initiation and progression comprehension, and further investigation could open the way to new therapeutics avenues to improve patient prognosis., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Sebaceous neoplasms (SNs) always raise the possibility of an association with Muir-Torre syndrome (MTS) and permit to screen internal malignancies, colorectal and endometrial carcinomas, before they become symptomatic. Immunohistochemistry (IHC), molecular biology, and clinical examination are different approaches for detection of MTS. We conducted a retrospective analysis of non-selected SNs in order to determine the optimal tools to implement for MTS screening., Methods: Deficient MMR phenotype (dMMR) was determined by either IHC using antibodies directed to four mismatch repair (MMR) antigens on tissue microarray or molecular biology using pentaplex PCR. The Mayo Clinic risk score of MTS was calculated from medical records. Sensibility and specificity of each test for the detection of MTS were determined., Results: We included 107 patients, 8 with multiple SNs, for a total of 123 SNs (43 sebaceous adenomas, 19 sebaceomas, and 61 sebaceous carcinomas (SC)). Loss of at least one MMR protein was observed in 70.7% of tumors, while 48% had a microsatellite instable phenotype. Concordance between both techniques was 92.9%, with a 0.85 Cohen's kappa coefficient. Nineteen patients (20.2%) had a ≥2 points Mayo Clinic risk score, one having a pMMR SC. Among the 13 patients with confirmed MTS, 2 had a low Mayo Clinic risk score (1 point). IHC had the highest sensitivity for MTS screening (100%) with a specificity of 34.1%, while a &gt;2-point Mayo Clinic risk score had a lower sensitivity (92%) but a higher specificity (89%)., Conclusion: To detect MTS in SN patients, the first-line Mayo Clinic risk score followed by IHC appears to be the most accurate strategy with lower cost for society. This strategy should be adapted to the medico-economic resources of each country., (© 2023 S. Karger AG, Basel.)

Besides the consequences of retrotransposition, long interspersed element 1 (L1) retrotransposons can affect the host genome through their antisense promoter. In addition to the sense promoter, the evolutionarily recent L1 retrotransposons, which are present in several thousand copies, also possess an anti-sense promoter that can produce L1 chimeric transcripts (LCT) composed of the L1 5' UTR followed by the adjacent genomic sequence. The full extent to which LCT expression occurs in a given tissue and whether disruption of the defense mechanisms that normally control L1 retrotransposons affects their expression and function in cancer cells, remain to be established. By using CLIFinder, a dedicated bioinformatics tool, we found that LCT expression was widespread in normal brain and aggressive glioma samples, and that approximately 17% of recent L1 retrotransposons, from the L1PA1 to L1PA7 subfamilies, were involved in their production. Importantly, the transcriptional activities of the L1 antisense promoters and of their host loci were coupled. Accordingly, we detected LCT-producing L1 retrotransposons mainly in transcriptionally active genes and genomic loci. Moreover, changes in the host genomic locus expression level in glioma were associated with a similar change in LCT expression level, regardless of the L1 promoter methylation status. Our findings support a model in which the host genomic locus transcriptional activity is the main driving force of LCT expression. We hypothesize that this model is more applicable when host gene and LCT are transcribed from the same strand., (© The Author(s) 2022. Published by Oxford University Press.)

Glioblastomas represent approximatively half of all gliomas and are the most deadly and aggressive form. Their therapeutic resistance and tumor relapse rely on a subpopulation of cells that are called Glioma Stem Cells (GSCs). Here, we investigated the role of the long non-coding RNA HOXA-AS2 in GSC biology using descriptive and functional analyses of glioma samples classified according to their isocitrate dehydrogenase ( IDH ) gene mutation status, and of GSC lines. We found that HOXA-AS2 is overexpressed only in aggressive ( IDHwt ) glioma and GSC lines. ShRNA-based depletion of HOXA-AS2 in GSCs decreased cell proliferation and altered the expression of several hundreds of genes. Integrative analysis revealed that these expression changes were not associated with changes in DNA methylation or chromatin signatures at the promoter of the majority of genes deregulated following HOXA-AS2 silencing in GSCs, suggesting a post-transcriptional regulation. In addition, transcription factor binding motif enrichment and correlation analyses indicated that HOXA-AS2 affects, directly or indirectly, the expression of key transcription factors implicated in GCS biology, including E2F8, E2F1, STAT1, and ATF3, thus contributing to GCS aggressiveness by promoting their proliferation and modulating the inflammation pathway.

Deficient mismatch repair system (dMMR)/microsatellite instability (MSI) is found in about 5% of metastatic colorectal cancers (mCRCs) with a major therapeutic impact for immune checkpoint inhibitor (ICI) use. We conducted a multicentre study including all consecutive patients with a dMMR/MSI mCRC. MSI status was determined using the Pentaplex panel and expression of the four MMR proteins was evaluated by immunohistochemistry (IHC). The primary endpoint was the rate of discordance of dMMR/MSI status between primary tumours and paired metastases. We included 99 patients with a dMMR/MSI primary CRC and 117 paired metastases. Only four discrepancies (3.4%) with a dMMR/MSI primary CRC and a pMMR/MSS metastasis were initially identified and reviewed by expert pathologists and molecular biologists. Two cases were false discrepancies due to human or technical errors. One discordant case could not be confirmed due to the low level of tumour cells. The last case had a confirmed discrepancy with a dMMR/MSI primary CRC and a pMMR/MSS peritoneal metastasis. Our study demonstrated a high concordance rate of dMMR/MSI status between primary CRCs and their metastases. The analysis of one sample, either from the primary tumour or metastasis, with consistent dMMR and MSI status seems to be sufficient prior to treatment with ICI.

Determination of microsatellite instability (MSI) using molecular test and deficient mismatch repair (dMMR) using immunohistochemistry (IHC) has major implications on colorectal cancer (CRC) management. The HSP110 T 17 microsatellite has been reported to be more monomorphic than the common markers used for MSI determination. Large deletion of HSP110 T 17 has been associated with efficacy of adjuvant chemotherapy in dMMR/MSI CRCs. The aim of this study was to evaluate the interest of HSP110 deletion/expression as a diagnostic tool of dMMR/MSI CRCs and a predictive tool of adjuvant chemotherapy efficacy. All patients with MSI CRC classified by molecular testing were included in this multicenter prospective cohort ( n = 381). IHC of the 4 MMR proteins was carried out. HSP110 expression was carried out by IHC ( n = 343), and the size of HSP110 T 17 deletion was determined by PCR (n = 327). In the 293 MSI CRCs with both tests, a strong correlation was found between the expression of HSP110 protein and the size of HSP110 T 17 deletion. Only 5.8% of MSI CRCs had no HSP110 T 17 deletion ( n = 19/327). HSP110 T 17 deletion helped to re-classify 4 of the 9 pMMR/MSI discordance cases as pMMR/MSS cases. We did not observe any correlation between HSP110 expression or HSP110 T 17 deletion size with time to recurrence in patients with stage II and III CRC, treated with or without adjuvant chemotherapy. HSP110 is neither a robust prognosis marker nor a predictor tool of adjuvant chemotherapy efficacy in dMMR/MSI CRC. However, HSP110 T 17 is an interesting marker, which may be combined with the other pentaplex markers to identify discordant cases between MMR IHC and MSI., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Tachon, Chong-Si-Tsaon, Lecomte, Junca, Frouin, Miquelestorena-Standley, Godet, Evrard, Randrian, Chautard, Auriault, Moulin, Guyetant, Fromont, Karayan-Tapon and Tougeron.)

Background: The difficulty in interpreting somatic alterations is correlated with the increase in sequencing panel size. To correctly guide the clinical management of patients with cancer, there needs to be accurate classification of pathogenicity followed by actionability assessment. Here, we describe a specific detailed workflow for the classification of the pathogenicity of somatic variants in cancer into five categories: benign, likely benign, unknown significance, likely pathogenic and pathogenic., Methods: Classification is obtained by combining a set of eight relevant criteria in favour of either a pathogenic or a benign effect (pathogenic stand-alone, pathogenic very strong, pathogenic strong, pathogenic moderate, pathogenic supporting, benign supporting, benign strong and benign stand-alone)., Results: Our guide is concordant with the ACMG/AMP 2015 guidelines for germline variants. Interpretation of somatic variants requires considering specific criteria, such as the disease and therapeutic context, co-occurring genomic events in the tumour when available and the use of cancer-specific variant databases. In addition, the gene role in tumorigenesis (oncogene or tumour suppressor gene) also needs to be taken into consideration., Conclusion: Our classification could contribute to homogenize best practices on somatic variant pathogenicity interpretation and improve interpretation consistency both within and between laboratories., Competing Interests: Conflict of interest statement The authors declare no conflict of interest., (Copyright © 2021. Published by Elsevier Ltd.)

The high expression of MEOX2 transcription factor is closely associated with poor overall survival in glioma. MEOX2 has recently been described as an interesting prognostic biomarker, especially for lower grade glioma. MEOX2 has never been studied in glioma stem-like cells (GSC), responsible for glioma recurrence. The aim of our study was to investigate the role of MEOX2 in GSC. Loss of function approach using siRNA was used to assess the impact of MEOX2 on GSC viability and stemness phenotype. MEOX2 was localized in the nucleus and its expression was heterogeneous between GSCs. MEOX2 expression depends on the methylation state of its promoter and is strongly associated with IDH mutations. MEOX2 is involved in cell proliferation and viability regulation through ERK/MAPK and PI3K/AKT pathways. MEOX2 loss of function correlated with GSC differentiation and acquisition of neuronal lineage characteristics. Besides, inhibition of MEOX2 is correlated with increased expression of CDH10 and decreased pFAK. In this study, we unraveled, for the first time, MEOX2 contribution to cell viability and proliferation through AKT/ERK pathway and its potential involvement in phenotype and adhesion properties of GSC.

Incidence of brain metastases has increased in patients with colorectal cancer (CRC) as their survival has improved. CD3 T-cells and, lately, DGMate (DiGital tuMor pArameTErs) score, have been identified as prognostic factors in locally advanced CRC. Until now, there is no data concerning the prognostic value of these markers in patients with CRC-derived brain metastases. All consecutive patients with CRC-derived brain metastases diagnosed between 2000 and 2017 were retrospectively included. Staining for CD3, CD8, PD-1, PD-L1 and DGMate analyses were performed using tissue micro-array from primary tumors and, if available, brain metastases. All in all, 83 patients were included with 80 primary tumor samples and 37 brain metastases samples available. CD3 and CD8 T-cell infiltration was higher in primary tumors compared to brain metastases. We observed a significant higher DGMate score in rectal tumors compared to colon tumors (p=0.03). We also noted a trend of higher CD3 T-cell infiltration in primary tumors when brain metastases were both supra and subtentorial compared to brain metastases that were only subtentorial or supratentorial (p=0.36 and p=0.03, respectively). No correlation was found between CD3 or CD8 infiltration or DGMate score in primary tumors or brain metastases and overall survival (OS) in the overall population. In patients with rectal tumors, a high DGMate score in brain metastases was associated with longer OS (13.4 ± 6.1 months versus 6.1 ± 1.4 months, p=0.02). High CD3 T-cell infiltration in brain metastases was associated with lower OS in patients with supratentorial brain metastases (9.8 ± 3.3 months versus 16.7 ± 5.9 months, p=0.03). PD-L1 overexpression was rare, both in primary tumors and brain metastases, but PD-L1 positive primary tumors were associated with worse OS (p=0.01). In contrast to breast and lung cancer derived brain metastases, CD3 and CD8 infiltration and DGMate score are not major prognostic factors in patients with CRC-derived brain metastases., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationship that could be construed as a potential conflict of interest., (Copyright © 2021 Randrian, Desette, Emambux, Derangere, Roussille, Frouin, Godet, Karayan-Tapon, Ghiringhelli and Tougeron.)

In human, the 39 coding HOX genes and 18 referenced noncoding antisense transcripts are arranged in four genomic clusters named HOXA, B, C, and D. This highly conserved family belongs to the homeobox class of genes that encode transcription factors required for normal development. Therefore, HOX gene deregulation might contribute to the development of many cancer types. Here, we study HOX gene deregulation in adult glioma, a common type of primary brain tumor. We performed extensive molecular analysis of tumor samples, classified according to their isocitrate dehydrogenase (IDH1) gene mutation status, and of glioma stem cells. We found widespread expression of sense and antisense HOX transcripts only in aggressive (IDHwt) glioma samples, although the four HOX clusters displayed DNA hypermethylation. Integrative analysis of expression, DNA methylation, and histone modification signatures along the clusters revealed that HOX gene upregulation relies on canonical and alternative bivalent CpG island promoters that escape hypermethylation. H3K27me3 loss at these promoters emerges as the main cause of widespread HOX gene upregulation in IDHwt glioma cell lines and tumors. Our study provides the first comprehensive description of the epigenetic changes at HOX clusters and their contribution to the transcriptional changes observed in adult glioma. It also identified putative 'master' HOX proteins that might contribute to the tumorigenic potential of glioma stem cells., (© 2021 The Authors. Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

The Hippo signaling pathway is a highly conserved pathway involved in tissue development and regeneration that controls organ size through the regulation of cell proliferation and apoptosis. The core Hippo pathway is composed of a block of kinases, MST1/2 (Mammalian STE20-like protein kinase 1/2) and LATS1/2 (Large tumor suppressor 1/2), which inhibits nuclear translocation of YAP/TAZ (Yes-Associated Protein 1/Transcriptional co-activator with PDZ-binding motif) and its downstream association with the TEAD (TEA domain) family of transcription factors. This pathway was recently shown to be involved in tumorigenesis and metastasis in several cancers such as lung, breast, or colorectal cancers but is still poorly investigated in brain tumors. Gliomas are the most common and the most lethal primary brain tumors representing about 80% of malignant central nervous system neoplasms. Despite intensive clinical protocol, the prognosis for patients remains very poor due to systematic relapse and treatment failure. Growing evidence demonstrating the role of Hippo signaling in cancer biology and the lack of efficient treatments for malignant gliomas support the idea that this pathway could represent a potential target paving the way for alternative therapeutics. Based on recent advances in the Hippo pathway deciphering, the main goal of this review is to highlight the role of this pathway in gliomas by a state-of-the-art synthesis.

Background: Epigenetic inactivation of O6-methylguanine-methyltransferase (MGMT) gene by methylation of its promoter is predictive of Temozolomid (TMZ) response in glioblastoma (GBM). MGMT is located on chromosome 10q26 and the loss of chromosome 10q is observed in 70% of GBMs. In this study, we assessed the hypothesis that the dual inactivation of MGMT, by hypermethylation of MGMT promoter and by loss the long arm of chromosome 10 (10q), may confer greater sensitivity to TMZ., Methods: A total of 149 tumor samples from patients diagnosed with GBM based on the WHO 2016 classification were included in this retrospective study between November 2016 and December 2018. Methylation status of MGMT promoter was evaluated by pyrosequencing and status of chromosome 10q was assessed by array comparative genomic hybridization., Results: Glioblastoma patients with chromosome 10q loss associated with hypermethylation of MGMT promoter had significantly longer overall survival (OS) (P = .0024) and progression-free survival (PFS) (P = .031). Indeed, median OS of patients with dual inactivation of MGMT was 21.5 months compared to 12 months and 8.1 months for groups with single MGMT inactivation by hypermethylation and by 10q loss, respectively. The group with no MGMT inactivation had 9.5 months OS. Moreover, all long-term survivors with persistent response to TMZ treatment (OS ≥ 30 months) displayed dual inactivation of MGMT., Conclusions: Our data suggest that the molecular subgroup characterized by the dual inactivation of MGMT receives greater benefit from TMZ treatment. The results of our study may be of immediate clinical interest since chromosome 10q status and methylation of MGMT promoter are commonly determined in routine practice., (© 2020 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Objective: Meningiomas have a female predilection, which is even stronger for spinal than for intracranial meningiomas. The relationship between meningiomas and endogenous or exogenous sex hormones such as cyproterone acetate (CPA) is well documented, yet their underlying mechanism remains unknown. Clarification of the expression profile of hormonal receptors by meningiomas would help us to better understand their hormonal susceptibility., Methods: We used tissue microarray and immunohistochemistry to determine the receptor status of the 3 main sex hormones: androgen (AR), estrogen, and progesterone (PR) in 30 intracranial meningiomas, 30 spinal meningiomas, and 30 meningiomas developed on CPA., Results: AR status was positive in 73% of meningiomas in the intracranial group, 87% of meningiomas in the CPA group, and in all meningiomas in the spinal group. Estrogen status was positive in only 7% of meningiomas in the intracranial group and in only 3% of meningiomas in the CPA group but in 30% of meningiomas in the spinal group. PR status was positive in 90% of meningiomas in the intracranial group, in 97% of meningiomas in the CPA group, and in 87% of meningiomas in the spinal group. These specific hormonal receptor statuses based on immunoreactive score were reflected on staining intensities. Furthermore, AR and PR expression was correlated in each group., Conclusions: Our study shows that intracranial meningiomas, spinal meningiomas, and meningiomas developed on CPA express specific hormonal receptor patterns. This result invites the scientific community to review the potential role of AR in the unbalanced sex ratio of meningiomas., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: In most countries, participation in colorectal cancer (CRC) screening programs with the immunological fecal occult blood test (iFOBT) is low. Mutations of RAS and BRAF occur early in colorectal carcinogenesis and "liquid biopsy" allows detection of mutated circulating tumor DNA (ctDNA). This prospective study aims to evaluate the performance of RAS and BRAF-mutated ctDNA in detecting CRC and advanced adenomas (AA)., Methods: One hundred and thirty patients who underwent colonoscopy for suspicion of colorectal lesion were included and divided into four groups: 20 CRC, 39 AA, 31 non-advanced adenoma and/or hyperplastic polyp(s) (NAA) and 40 with no lesion. Mutated ctDNA was analyzed by droplet digital PCR., Results: ctDNA was detected in 45.0% of CRC, in 2.6% of AA and none of the NAA and "no-lesion" groups. All patients with stage II to IV mutated CRC had detectable ctDNA ( n = 8/8). Among the mutated AA, only one patient had detectable ctDNA (4.3%), maybe due to limited technical sensitivity or to a low rate of ctDNA or even the absence ctDNA in plasma. Specificity and sensitivity of KRAS- and BRAF-mutated ctDNA for the detection of all CRC and AA were 100% and 16.9%, respectively., Conclusions: ctDNA had high sensitivity in detection of advanced mutated CRC but was unable to sensitively detect AA. ctDNA analysis was easy to perform and readily accepted by the population but requires combination with other circulating biomarkers before replacing iFOBT.

Introduction: ALK and ROS1 rearrangements are molecular targets of several tyrosine kinase inhibitors. RNA-sequencing approaches are regarded as the new standard for fusion gene detection, representing an alternative to standard immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) techniques., Patients and Methods: We aimed to compare two recent amplicon-based RNA-sequencing techniques: FusionPlex ® Alk Ret Ros1 v2 Kit (Archer ® ) with FHS-003Z-12-Human Lung Cancer Panel (Qiagen ® ) and assessed the accuracy of the data for therapy management. Thirty-seven formalin-fixed paraffin-embedded non-small cell carcinoma (NSCC) lesions initially explored by IHC and FISH were selected for RNA-sequencing analysis., Results: Qiagen ® and Archer ® kits produced similar results and correctly identified 85.1% (23/27) and 81.5% (22/27) of IHC/FISH ALK- and ROS1-positive samples, respectively, and 100% (6/6) of the negative samples. With regard to the ambiguous IHC-positive/FISH-negative cases, RNA-sequencing confirmed 75% (3/4) of the FISH conclusion. Although not statistically significant, patients with common EML4-ALK variants presented shorter overall survival and progression-free survival compared with patients harboring rare variants., Conclusion: Our findings assessed the implementation of RNA-sequencing approaches to explore ALK and ROS1 rearrangements from formalin-fixed paraffin-embedded samples. We highlighted the similarities between Qiagen ® and Archer ® kits in terms of handling time, cost, and outcomes. We confirmed the feasibility of molecular testing in routine organization and its possible use not only as an alternative for standard IHC and FISH techniques, but as a supplementary technique helping to classify discrepant cases., (© 2019 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Tumor DNA mismatch repair (MMR) deficiency testing is important to the identification of Lynch syndrome and decision making regarding adjuvant chemotherapy in stage II colorectal cancer (CRC) and has become an indispensable test in metastatic tumors due to the high efficacy of immune checkpoint inhibitor (ICI) in deficient MMR (dMMR) tumors. CRCs greatly benefit from this testing as approximately 15% of them are dMMR but only 3% to 5% are at a metastatic stage. MMR status can be determined by two different methods, microsatellite instability (MSI) testing on tumor DNA, and immunohistochemistry of the MMR proteins on tumor tissue. Recent studies have reported a rate of 3% to 10% of discordance between these two tests. Moreover, some reports suggest possible intra- and inter-tumoral heterogeneity of MMR and MSI status. These issues are important to know and to clarify in order to define therapeutic strategy in CRC. This review aims to detail the standard techniques used for the determination of MMR and MSI status, along with their advantages and limits. We review the discordances that may arise between these two tests, tumor heterogeneity of MMR and MSI status, and possible explanations. We also discuss the strategies designed to distinguish sporadic versus germline dMMR/MSI CRC. Finally, we present new and accurate methods aimed at determining MMR/MSI status ., Competing Interests: Abbreviations:

In cancer cells, aberrant DNA methylation is commonly associated with transcriptional alterations, including silencing of tumor suppressor genes. However, multiple epigenetic mechanisms, including polycomb repressive marks, contribute to gene deregulation in cancer. To dissect the relative contribution of DNA methylation-dependent and -independent mechanisms to transcriptional alterations at CpG island/promoter-associated genes in cancer, we studied 70 samples of adult glioma, a widespread type of brain tumor, classified according to their isocitrate dehydrogenase ( IDH1 ) mutation status. We found that most transcriptional alterations in tumor samples were DNA methylation-independent. Instead, altered histone H3 trimethylation at lysine 27 (H3K27me3) was the predominant molecular defect at deregulated genes. Our results also suggest that the presence of a bivalent chromatin signature at CpG island promoters in stem cells predisposes not only to hypermethylation, as widely documented, but more generally to all types of transcriptional alterations in transformed cells. In addition, the gene expression strength in healthy brain cells influences the choice between DNA methylation- and H3K27me3-associated silencing in glioma. Highly expressed genes were more likely to be repressed by H3K27me3 than by DNA methylation. Our findings support a model in which altered H3K27me3 dynamics, more specifically defects in the interplay between polycomb protein complexes and the brain-specific transcriptional machinery, is the main cause of transcriptional alteration in glioma cells. Our study provides the first comprehensive description of epigenetic changes in glioma and their relative contribution to transcriptional changes. It may be useful for the design of drugs targeting cancer-related epigenetic defects., (© 2019 Court et al.; Published by Cold Spring Harbor Laboratory Press.)

Gliomas are the most common malignant primary tumors in the central nervous system and have variable predictive clinical courses. Glioblastoma, the most aggressive form of glioma, is a complex disease with unsatisfactory therapeutic solutions and a very poor prognosis. Some processes at stake in gliomagenesis have been discovered but little is known about the role of homeobox genes, even though they are highly expressed in gliomas, particularly in glioblastoma. Among them, the transcription factor Mesenchyme Homeobox 2 (MEOX2) had previously been associated with malignant progression and clinical prognosis in lung cancer and hepatocarcinoma but never studied in glioma. The aim of our study was to investigate the clinical significance of MEOX2 in gliomas. We assessed the expression of MEOX2 according to IDH1/2 molecular profile and patient survival among three different public datasets: The Cancer Genome Atlas (TCGA), The Chinese Glioma Genome Atlas (CGGA) and the US National Cancer Institute Repository for Molecular Brain Neoplasia Data (Rembrandt). We then evaluated the prognostic significance of MEOX2 protein expression on 112 glioma clinical samples including; 56 IDH1 wildtype glioblastomas, 7 IDH1 wild-type lower grade gliomas, 49 IDH1 mutated lower grade gliomas. Survival rates were estimated by the Kaplan-Meier method followed by uni/multivariate analyses. We demonstrated that MEOX2 was one of the transcription factors most closely associated with overall survival in glioma. Moreover, MEOX2 expression was associated with IDH1/2 wildtype molecular subtype and was significantly correlated with overall survival of all gliomas and, more interestingly, in lower grade glioma. To conclude, our results may be the first to provide insight into the clinical significance of MEOX2 in gliomas, which is a factor closely related to patient outcome. MEOX2 could constitute an interesting prognostic biomarker, especially for lower grade glioma.

Background: Meningiomas are the most common primary intracranial tumors in adults. The relationship between meningiomas and exogenous sex hormones such as cyproterone acetate (CPA) is well documented, yet the underlying mechanisms remain unknown. Defining the histomolecular status of meningiomas developed on CPA would help us to better understand the oncogenesis of these tumors., Methods: We identified 30 patients operated for a meningioma after long-term high-dose CPA therapy and with a history of CPA discontinuation before establishing the indication for surgical intervention. We used array-comparative genomic hybridization (to characterize copy number changes in those 30 meningiomas and subsequently performed next-generation sequencing with the National Institute of Cancer (INCa) solid tumor panel, which is a targeted panel of clinically actionable genes. We also examined grade, type, and clinical features., Results: We identified AKT1 mutations or PIK3CA mutations in 33.3% of CPA meningiomas. AKT1 and PIK3CA mutations were mutually exclusive. Enrichment in oncogenic PIK3CA mutations in the CPA cohort was detected. CPA meningiomas showed chromosomal stability and were located mainly in the skull base. Ninety percent of CPA meningiomas were low-grade meningiomas and 63.4% were meningotheliomas. Half of our CPA cohort had microcystic components., Conclusion: Our study shows that low-grade meningothelial meningiomas of the skull base are predominant in CPA meningiomas. We identified PIK3CA/AKT1 pathway as a hypothetical actor in onco-pharmacological interaction between meningiomas and CPA. This signaling pathway could be an interesting target for precision medicine trials in meningioma patients who have been subjected to CPA. Our results could invite the scientific community to review the current classification of meningiomas and to evolve toward more specific histomolecular classification., (© The Author(s) 2019. Published by Oxford University Press, the Society for Neuro-Oncology and the European Association of Neuro-Oncology.)

Background: Colorectal cancers (CRC) with brain metastases (BM) are scarcely described. The main objective of this study was to determine the molecular profile of CRC with BM. Methods: We included 82 CRC patients with BM. KRAS , NRAS , BRAF and mismatch repair (MMR) status were investigated on primary tumors ( n = 82) and BM ( n = 38). ALK, ROS1, cMET, HER-2, PD-1, PD-L1, CD3 and CD8 status were evaluated by immunohistochemistry, and when recommended, by fluorescence in situ hybridization. Results: In primary tumors, KRAS , NRAS and BRAF mutations were observed in 56%, 6%, and 6% of cases, respectively. No ROS1 , ALK and cMET rearrangement was detected. Only one tumor presented HER-2 amplification. Molecular profiles were mostly concordant between BM and paired primary tumors, except for 9% of discordances for RAS mutation. CD3, CD8, PD-1 and PD-L1 expressions presented some discordance between primary tumors and BM. In multivariate analysis, multiple BM, lung metastases and PD-L1+ tumor were predictive of poor overall survival. Conclusions: CRCs with BM are associated with high frequency of RAS mutations and significant discordance for RAS mutational status between BM and paired primary tumors. Multiple BM, lung metastases and PD-L1+ have been identified as prognostic factors and can guide therapeutic decisions for CRC patients with BM., Competing Interests: The authors declare no conflict of interest.

"Glioma Stem Cells" (GSCs) are known to play a role in glioblastoma (GBM) recurrence. Homologous recombination (HR) defects and cell cycle checkpoint abnormalities can contribute concurrently to the radioresistance of GSCs. DNA repair protein RAD51 homolog 1 (RAD51) is a crucial protein for HR and its inhibition has been shown to sensitize GSCs to irradiation. The aim of this study was to examine the consequences of ionizing radiation (IR) for cell cycle progression in GSCs. In addition, we intended to assess the potential effect of RAD51 inhibition on cell cycle progression. Five radiosensitive GSC lines and five GSC lines that were previously characterized as radioresistant were exposed to 4Gy IR, and cell cycle analysis was done by fluorescence-activated cell sorting (FACS) at 24, 48, 72, and 96 h with or without RAD51 inhibitor. Following 4Gy IR, all GSC lines presented a significant increase in G2 phase at 24 h, which was maintained over 72 h. In the presence of RAD51 inhibitor, radioresistant GSCs showed delayed G2 arrest post-irradiation for up to 48 h. This study demonstrates that all GSCs can promote G2 arrest in response to radiation-induced DNA damage. However, following RAD51 inhibition, the cell cycle checkpoint response differed. This study contributes to the characterization of the radioresistance mechanisms of GSCs, thereby supporting the rationale of targeting RAD51-dependent repair pathways in view of radiosensitizing GSCs.

During the last decade, large-scale genomic analyses have clarified the somatic alterations in gliomas, providing new molecular classification based on IDH1/2 mutations and 1p19q codeletion with more accurate patient prognostication. The Hippo pathway downstream effectors, YAP1 and TAZ, have recently emerged as major determinants of malignancy by inducing proliferation, chemoresistance, and metastasis in solid tumors. In this study, we investigated the expression of YAP1 in 117 clinical samples of glioma described according to the WHO 2016 classification. We showed for the first time that YAP1 was tightly associated with glioma molecular subtypes and patient outcome. We validated our results in an independent cohort from the TCGA database. More interestingly, we found that YAP1 may have prognostic significance for predicting patient survival, especially in low-grade gliomas. Using patient-derived glioblastoma stem cell cultures, we demonstrated that YAP1 was activated and that it controlled cell proliferation. Transcriptome analysis revealed lower expression of YAP1 in the proneural GBM subtype. Furthermore, we found that overexpression of YAP1 was sufficient to inhibit the OLIG2 proneural marker, suggesting its involvement in maintenance of the GBM phenotype. Taken together, our results showed that YAP1 could be a relevant prognostic biomarker and a potential therapeutic target in glioma. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd., (Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

Glioblastoma (GBM) represents the most common and lethal brain tumor. High vascularization, necrosis and invasiveness are hallmarks of GBM aggressiveness with recent data suggesting the important role of glioblastoma stem cells (GSCs) in these processes. It is now well established that cancer cells employ specialized structures termed invadosomes to potentiate invasion. However, the role of these structures in GBM dissemination remains poorly investigated. In this study, we showed that GBM-isolated GSCs form invadopodia-like protrusions endowed with degradative action. Interestingly, their formation depends on extracellular matrix (ECM) sensing via the CD44 receptor. We also found that GSCs invasive migration occurring during tubes assembly is promoted through invadopodia-mediated-ECM remodeling and LIM kinases signaling. Moreover, our study demonstrates that GSCs are highly adaptable cells that are able not only to restore damaged endothelial-derived tubes but also to generate in cooperation with normal endothelial cells (ECs) intact vascular channels. Taken together, our data provide new insights in GBM microvasculature and suggest that GSCs targeting in combination with anti-VEGF therapy may block tumor progression., Competing Interests: CONFLICTS OF INTEREST The authors declare no potential conflicts of interest.

In colorectal cancer, KRAS (exons 2, 3, and 4) and NRAS (exons 2, 3, and 4) mutations are associated with resistance to antiepidermal growth factor receptor monoclonal antibodies, and BRAF mutation is a molecular marker of poor prognosis. KRAS exon 2 and BRAF-mutated colorectal cancers have well-known distinct clinicopathological characteristics. Comparison of tumors with different RAS status (exons 2, 3, and 4 of KRAS and NRAS) based on their clinicopathological characteristics has never been established. All colorectal cancer patients with RAS and BRAF testing from 2011 to 2015 were included in this observational retrospective study. Patient and tumor characteristics were collected and correlation with RAS and BRAF status was evaluated. A total of 1735 patients with colorectal cancer were included. RAS-mutated colorectal cancers (n=1002), compared with RAS wild-type colorectal cancers (n=733), were significantly associated with male gender, classical adenocarcinoma subtype, well/moderately differentiated tumors, and microsatellite stable phenotype. KRAS codon 13-mutated colorectal cancers (n=171), compared with RAS wild-type colorectal cancers, more frequently presented classical adenocarcinoma subtype and microsatellite stable phenotype. In comparison with other RAS mutations, KRAS exon 3-mutated colorectal cancers (n=23) were associated with mucinous/rare histological subtypes and, most likely to located in the rectum. KRAS exon 4-mutated colorectal cancers (n=33) were more frequently associated with mucinous/rare histological subtypes. There was no significant association between NRAS mutation (n=37) and clinicopathological features. Colorectal cancers are associated with different clinicopathological features according to the type of RAS mutation. Consequently, these particular characteristics must be considered when assessing the prognostic value of RAS status in colorectal cancer.

Glioblastoma (GBM) represents the most common and lethal primary malignant brain tumor. The standard treatment for glioblastoma patients involves surgical resection with concomitant radio and chemotherapy. Despite today's clinical protocol, the prognosis for patients remains very poor with a median survival of 15 months. Tumor resistance and recurrence is strongly correlated with a subpopulation of highly radioresistant and invasive cells termed Glioblastoma Stem Cells (GSCs). The transcription factor STAT3 has been found to be constitutively activated in different tumors including GBM and enhanced tumor radioresistance. In this study, we assessed radiosensitization of GSC lines isolated from patients by inhibition of STAT3 activation using Stattic or WP1066. We showed that inhibitor treatment before cell irradiation decreased the surviving fraction of GSCs suggesting that STAT3 inhibition could potentiate radiation effects. Finally, we investigated STAT3 activation status on 61 GBM clinical samples and found a preferential phosphorylation of STAT3 on Serine727 (pS727). Moreover, we found that pS727 was associated with a significant lower overall patient survival and progression-free survival but not pY705. Taken together, our results suggest that pS727-STAT3 could be a potential prognostic marker and could constitute a therapeutic target to sensitize highly radioresistant GSCs., Competing Interests: CONFLICTS OF INTEREST The authors have no conflicts to disclose.