The tumoral A genotype of the MGMT rs34180180 single-nucleotide polymorphism in aggressive gliomas is associated with shorter patients' survival

Malignant gliomas are the most common primary brain tumors. Grade III and IV gliomas harboring wild-type IDH1/2 are the most aggressive. In addition to surgery and radiotherapy, concomitant and adjuvant chemotherapy with temozolomide (TMZ) significantly improves overall survival (OS). The methylation status of the O-6-methylguanine-DNA methyltransferase (MGMT) promoter is predictive of TMZ response and a prognostic marker of cancer outcome. However, the promoter regions the methylation of which correlates best with survival in aggressive glioma and whether the promoter methylation status predictive value could be refined or improved by other MGMT-associated molecular markers are not precisely known. In a cohort of 87 malignant gliomas treated with radiotherapy and TMZ-based chemotherapy, we retrospectively determined the MGMT promoter methylation status, genotyped single nucleotide polymorphisms (SNPs) in the promoter region and quantified MGMT mRNA expression level. Each of these variables was correlated with each other and with the patients' OS. We found that methylation of the CpG sites within MGMT exon 1 best correlated with OS and MGMT expression levels, and confirmed MGMT methylation as a stronger independent prognostic factor compared to MGMT transcription levels. Our main finding is that the presence of only the A allele at the rs34180180 SNP in the tumor was significantly associated with shorter OS, independently of the MGMT methylation status. In conclusion, in the clinic, rs34180180 SNP genotyping could improve the prognostic value of the MGMT promoter methylation assay in patients with aggressive glioma treated with TMZ.ARC -Fondation ARC pour la Recherche sur le Cancer(EML20120904843

Outcomes among oropharyngeal and oral cavity cancer patients treated with postoperative volumetric modulated arctherapy

BackgroundPresently, there are few published reports on postoperative radiation therapy for oropharyngeal and oral cavity cancers treated with IMRT/VMAT technique. This study aimed to assess the oncological outcomes of this population treated with postoperative VMAT in our institution, with a focus on loco-regional patterns of failure.Material and methodsBetween 2011 and 2019, 167 patients were included (40% of oropharyngeal cancers, and 60% of oral cavity cancers). The median age was 60 years. There was 64.2% of stage IV cancers. All patients had both T and N surgery. 34% had a R1 margin, 42% had perineural invasion. 72% had a positive neck dissection and 42% extranodal extension (ENE). All patients were treated with VMAT with simultaneous integrated boost with three dose levels: 66Gy in case of R1 margin and/or ENE, 59.4-60Gy on the tumor bed, and 54Gy on the prophylactic areas. Concomittant cisplatin was administrated concomitantly when feasible in case of R1 and/or ENE.ResultsThe 1- and 2-year loco-regional control rates were 88.6% and 85.6% respectively. Higher tumor stage (T3/T4), the presence of PNI, and time from surgery >45 days were significant predictive factors of worse loco-regional control in multivariate analysis (p=0.02, p=0.04, and p=0.02). There were 17 local recurrences: 11 (64%) were considered as infield, 4 (24%) as marginal, and 2 (12%) as outfield. There were 9 regional recurrences only, 8 (89%) were considered as infield, and 1 (11%) as outfield. The 1- and 2-year disease-free survival (DFS) rates were 78.9% and 71.8% respectively. The 1- and 2-year overall survival (OS) rates were 88.6% and 80% respectively. Higher tumor stage (T3/T4) and the presence of ENE were the two prognostic factors significantly associated with worse DFS and OS in multivariate analysis.ConclusionOur outcomes for postoperative VMAT for oral cavity and oropharyngeal cancers are encouraging, with high rates of loco-regional control. However, the management of ENE still seems challenging

WNT6 is a novel oncogenic prognostic biomarker in human glioblastoma

Glioblastoma (GBM) is a universally fatal brain cancer, for which novel therapies targeting specific underlying oncogenic events are urgently needed. While the WNT pathway has been shown to be frequently activated in GBM, constituting a potential therapeutic target, the relevance of WNT6, an activator of this pathway, remains unknown. Methods: WNT6 protein and mRNA levels were evaluated in GBM. WNT6 levels were silenced or overexpressed in GBM cells to assess functional effects in vitro and in vivo. Phospho-kinase arrays and TCF/LEF reporter assays were used to identify WNT6-signaling pathways, and significant associations with stem cell features and cancer-related pathways were validated in patients. Survival analyses were performed with Cox regression and Log-rank tests. Meta-analyses were used to calculate the estimated pooled effect. Results: We show that WNT6 is significantly overexpressed in GBMs, as compared to lower-grade gliomas and normal brain, at mRNA and protein levels. Functionally, WNT6 increases typical oncogenic activities in GBM cells, including viability, proliferation, glioma stem cell capacity, invasion, migration, and resistance to temozolomide chemotherapy. Concordantly, in in vivo orthotopic GBM mice models, using both overexpressing and silencing models, WNT6 expression was associated with shorter overall survival, and increased features of tumor aggressiveness. Mechanistically, WNT6 contributes to activate typical oncogenic pathways, including Src and STAT, which intertwined with the WNT pathway may be critical effectors of WNT6-associated aggressiveness in GBM. Clinically, we establish WNT6 as an independent prognostic biomarker of shorter survival in GBM patients from several independent cohorts. Conclusion: Our findings establish WNT6 as a novel oncogene in GBM, opening opportunities to develop more rational therapies to treat this highly aggressive tumor.FCT - Foundation for Science and Technology (PTDC/SAU-GMG/113795/2009 and IF/00601/2012 to B.M.C.; SFRH/BD/92786/2013 to C.S.G.; SFRH/BD/88121/2012 to J.V.C.; SFRH/BD/81042/2011 to M.P.; SFRH/BD/93443/2013 to S.Q.) and Fundação Calouste Gulbenkian (B.M.C.), by FEDER funds through the Operational Programme Competitiveness Factors - COMPETE and National Funds through FCT under the project POCI-01-0145-FEDER-007038; by the project NORTE-01-0145-FEDER-000013 and NORTE-01-0246-FEDER-000012, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF); and by the project NORTE-01-0145-FEDER-000023, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER)info:eu-repo/semantics/publishedVersio

Rôle de la voie de signalisation Interleukine-6 dans la radiorésistance des glioblastomes humains

Identification and neutralization of molecular targets involved in human glioblastomaradioresistance mechanisms is an approach developped in the laboratory to decrease recurrence inside irradiated volum and then to increase patient survival. Previous data published by the team have demonstrated a potential role of interleukin-6 (IL-6) in anti-apoptotic mechanism involved in radioresistance. Firstly, we contributed to IL-6 validation as a potential target by demonstrating association between amplification with overexpression of IL-6 gene and a bad prognosis in 36 glioblastoma. Median survival dropped from 22 to 6 months between IL-6 non-amplified and amplified group. Although, we have found no correlation between intrinsic radioresistance and expression or IL-6 production in vitro, published data prompted us to explore therapeutic potential of blocking IL-6 downtream signaling pathways such as PI3K/Akt and JAK/STAT3. Akt pathway inhibition, whose activation has been correlated with intrinsic radioresistance, radiosensitizes glioblastoma in vitro whereas STAT3 inhibition did not affect ionizing radiation sensitivity. Accordingly, second approach using antibodies against IL-6 or its receptor subunits induced a decrease in STAT3 pathway activation whitout any effect on radioresistance. Results provided by this work suggest that IL-6, despite being a prognosis factor, and STAT3 pathway are not involved in intrinsic radioresistance. Our hypothesis is that in glioma, frequently activated STAT3 pathway is involved in micro-environnement alteration such as immunosuppression and angiogenesis as described in the litterature. To explain survival variation between the two groups of patients, comparative analyses are ongoing, on the one hand genomic and transcriptomic profiling by micro-arrays, and on the other hand studies of activation level of Akt and STAT3 anti-apoptotic pathways by immunohistochemmistry. The data will be interpreted together with the level of amplification/expression of IL-6 and survival of patients. Results obtained here give us a rationale for using Akt inhibitor combined with irradiation in future clinical trials.L'identification et la neutralisation des cibles moléculaires impliquées dans les mécanismes de radiorésistance des glioblastomes, approche développée au laboratoire, vise à diminuer le risque de récidive à l'intérieur du volume irradié et donc à allonger la survie des patients. Les travaux antérieurs du laboratoire ont démontré le rôle potentiel de l'interleukine-6 (IL-6) dans les mécanismes anti-apoptotiques impliqués dans la radiorésistance. Nous avons tout d'abord contribué à la validation de l'Interleukine-6 en tant que cible potentielle en rapportant l'association entre une amplification avec surexpression du gène IL-6 et un mauvais pronostic dans une série de 36 glioblastomes. La médiane de survie chute de 22 à 6 mois entre le groupe IL-6 non amplifié et amplifié. Bien que nous n'ayons pas établi de corrélation entre la radiorésistance intrinsèque et le niveau d'expression et de production d'IL-6 in vitro, les données de la littérature nous ont incité à explorer le potentiel thérapeutique d'un blocage des voies PI3K/Akt et JAK/STAT3 situées en aval de l'IL-6. L'inhibition de la voie Akt, dont l'activation a été corrélée à la radiorésistance intrinsèque, permet de radiosensibiliser les glioblastomes in vitro alors que celle de la voie STAT3 s'est révélée sans impact sur la sensibilité à l'irradiation. En accord avec ces résultats, la 2ème approche, consistant en l'utilisation d'anticorps dirigés contre l'IL-6 ou les sous unités qui composent son récepteur conduit à une inactivation de la voie STAT3 sans impact sur la radiorésistance. Au vu des données apportées par ce travail il semble que l'IL-6, malgré son statut de facteur de pronostique, et la voie STAT3 ne soient pas impliqués dans la radiorésistance intrinsèque. Notre hypothèse, en accord avec la littérature, est que l'activation aberrante de la voie STAT3 dans les gliomes, via la production d'IL-6, serait impliquée dans les modifications du micro-environnement telles que l'immunosuppression et l'angiogénèse. Pour tenter d'expliquer la différence de survie entre les deux groupes de patients de la série de 31 glioblastomes, une analyse comparative est en cours d'une part sur les profils génomiques et transcriptomiques par micro-arrays, et d'autre part sur l'état d'activation des voies de signalisation anti-apoptotiques Akt et STAT3 par immunohostochimie. Les données obtenues seront interprétées conjointement avec le niveau d'amplification/expression de l'IL-6 et la survie des patients. Les résultats présentés ici constituent un argumentaire pour l'utilisation d'inhibiteurs d'Akt en combinaison avec l'irradiation dans de futurs essais cliniques

Rôle de la voie de signalisation Interleukine-6 dans la radiorésistance des glioblastomes humains

L'identification et la neutralisation des cibles moléculaires impliquées dans les mécanismes de radiorésistance des glioblastomes, approche développée au laboratoire, vise à diminuer le risque de récidive à l'intérieur du volume irradié et donc à allonger la survie des patients. Les travaux antérieurs du laboratoire ont démontré le rôle potentiel de l'interleukine-6 (IL-6) dans les mécanismes anti-apoptotiques impliqués dans la radiorésistance. Nous avons tout d'abord contribué à la validation de l'Interleukine-6 en tant que cible potentielle en rapportant l'association entre une amplification avec surexpression du gène IL-6 et un mauvais pronostic dans une série de 36 glioblastomes. La médiane de survie chute de 22 à 6 mois entre le groupe IL-6 non amplifié et amplifié. Bien que nous n'ayons pas établi de corrélation entre la radiorésistance intrinsèque et le niveau d'expression et de production d'IL-6 in vitro, les données de la littérature nous ont incité à explorer le potentiel thérapeutique d'un blocage des voies PI3K/Akt et JAK/STAT3 situées en aval de l'IL-6. L'inhibition de la voie Akt, dont l'activation a été corrélée à la radiorésistance intrinsèque, permet de radiosensibiliser les glioblastomes in vitro alors que celle de la voie STAT3 s'est révélée sans impact sur la sensibilité à l'irradiation. En accord avec ces résultats, la 2ème approche, consistant en l'utilisation d'anticorps dirigés contre l'IL-6 ou les sous unités qui composent son récepteur conduit à une inactivation de la voie STAT3 sans impact sur la radiorésistance. Au vu des données apportées par ce travail il semble que l'IL-6, malgré son statut de facteur de pronostique, et la voie STAT3 ne soient pas impliqués dans la radiorésistance intrinsèque. Notre hypothèse, en accord avec la littérature, est que l'activation aberrante de la voie STAT3 dans les gliomes, via la production d'IL-6, serait impliquée dans les modifications du micro-environnement telles que l'immunosuppression et l'angiogénèse. Pour tenter d'expliquer la différence de survie entre les deux groupes de patients de la série de 31 glioblastomes, une analyse comparative est en cours d'une part sur les profils génomiques et transcriptomiques par micro-arrays, et d'autre part sur l'état d'activation des voies de signalisation anti-apoptotiques Akt et STAT3 par immunohostochimie. Les données obtenues seront interprétées conjointement avec le niveau d'amplification/expression de l'IL-6 et la survie des patients. Les résultats présentés ici constituent un argumentaire pour l'utilisation d'inhibiteurs d'Akt en combinaison avec l'irradiation dans de futurs essais cliniques.Identification and neutralization of molecular targets involved in human glioblastomaradioresistance mechanisms is an approach developped in the laboratory to decrease recurrence inside irradiated volum and then to increase patient survival. Previous data published by the team have demonstrated a potential role of interleukin-6 (IL-6) in anti-apoptotic mechanism involved in radioresistance. Firstly, we contributed to IL-6 validation as a potential target by demonstrating association between amplification with overexpression of IL-6 gene and a bad prognosis in 36 glioblastoma. Median survival dropped from 22 to 6 months between IL-6 non-amplified and amplified group. Although, we have found no correlation between intrinsic radioresistance and expression or IL-6 production in vitro, published data prompted us to explore therapeutic potential of blocking IL-6 downtream signaling pathways such as PI3K/Akt and JAK/STAT3. Akt pathway inhibition, whose activation has been correlated with intrinsic radioresistance, radiosensitizes glioblastoma in vitro whereas STAT3 inhibition did not affect ionizing radiation sensitivity. Accordingly, second approach using antibodies against IL-6 or its receptor subunits induced a decrease in STAT3 pathway activation whitout any effect on radioresistance. Results provided by this work suggest that IL-6, despite being a prognosis factor, and STAT3 pathway are not involved in intrinsic radioresistance. Our hypothesis is that in glioma, frequently activated STAT3 pathway is involved in micro-environnement alteration such as immunosuppression and angiogenesis as described in the litterature. To explain survival variation between the two groups of patients, comparative analyses are ongoing, on the one hand genomic and transcriptomic profiling by micro-arrays, and on the other hand studies of activation level of Akt and STAT3 anti-apoptotic pathways by immunohistochemmistry. The data will be interpreted together with the level of amplification/expression of IL-6 and survival of patients. Results obtained here give us a rationale for using Akt inhibitor combined with irradiation in future clinical trials.CLERMONT FD-BCIU-Santé (631132104) / SudocSudocFranceF

Interest and Limits of [18F]ML-10 PET Imaging for Early Detection of Response to Conventional Chemotherapy

International audienceOne of the current challenges in oncology is to develop imaging tools to early detect the response to conventional chemotherapy and adjust treatment strategies when necessary. Several studies evaluating PET imaging with 2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]FDG) as a predictive tool of therapeutic response highlighted its insufficient specificity and sensitivity. The [ 18 F]FDG uptake reflects only tumor metabolic activity and not treatment-induced cell death, which seems to be relevant for therapeutic evaluation. Therefore, to evaluate this parameter in vivo , several cell death radiotracers have been developed in the last years. However, few of them have reached the clinical trials. This systematic review focuses on the use of [ 18 F]ML-10 (2-(5-[ 18 F]fluoropentyl)-2-methylmalonic acid) as radiotracer of apoptosis and especially as a measure of tumor response to treatment. A comprehensive literature review concerning the preclinical and clinical investigations conducted with [ 18 F]ML-10 was performed. The abilities and applications of this radiotracer as well as its clinical relevance and limitations were discussed. Most studies highlighted a good ability of the radiotracer to target apoptotic cells. However, the increase in apoptosis during treatment did not correlate with the radiotracer tumoral uptake, even using more advanced image analysis (voxel-based analysis). [ 18 F]ML-10 PET imaging does not meet current clinical expectations for early detection of the therapeutic response to conventional chemotherapy. This review has pointed out the challenges of applying various apoptosis imaging strategies in clinical trials, the current methodologies available for image analysis and the future of molecular imaging to assess this therapeutic response

Role of STAT3 in Genesis and Progression of Human Malignant Gliomas

International audienceSignal Transducer and Activator of Transcription 3 (STAT3) is aberrantly activated in glioblastoma and has been identified as a relevant therapeutic target in this disease and many other human cancers. After two decades of intensive research, there is not yet any approved STAT3-based glioma therapy. In addition to the canonical activation by tyrosine 705 phosphorylation, concordant reports described a potential therapeutic relevance of other post-translational modifications including mainly serine 727 phosphorylation. Such reports reinforce the need to refine the strategy of targeting STAT3 in each concerned disease. This review focuses on the role of serine 727 and tyrosine 705 phosphorylation of STAT3 in glioma. It explores their contribution to glial cell transformation and to the mechanisms that make glioma escape to both immune control and standard treatment

Akt signaling pathway: a target for radiosensitizing human malignant glioma

Radiation therapy plays a central role in the treatment of glioblastoma, but it is not curative due to the high tumor radioresistance. Phosphatidyl-inositol 3-kinase/protein kinase B (Akt) and Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) pathways serve to block the apoptosis process, keeping cells alive in very toxic environments such as chemotherapy or ionizing radiation. In the present study, from a panel of 8 human malignant glioma cell lines, investigations on the relationship between intrinsic radioresistance and Akt or STAT3 basal activation were done. Secondly, the impact of down-modulation of Akt or STAT3 signaling on in vitro intrinsic radiosensitivity was evaluated. Using a clonogenic cell survival assay, our results revealed a significant correlation between the basal Akt activation and the surviving fraction at 2 Gy (SF2). In contrast, no correlation was found between STAT3 activation and SF2. According to this, down-modulation of Akt with a specific chemical inhibitor (Akt inhibitor IV) demonstrated a significant enhancement of radiation sensitivity on glioma cells in a clonogenic survival assay. On the contrary, down-modulation of STAT3 signaling with a specific chemical inhibitor (JSI-124) or a neutralizing gp130 antibody failed to radiosensitize glioma cells. These data indicate that the Akt intercept node could be a more relevant therapeutic target than STAT3 for radiosensitizing human malignant glioma