Chemotherapy is the only systemic treatment approved for pancreatic ductal adenocarcinoma (PDAC), with a selection of regimens based on patients' performance status and expected efficacy. The ...establishment of a potent stratification associated with chemotherapeutic efficacy could potentially improve prognosis by tailoring treatments.
Concomitant chemosensitivity and genome-wide RNA profiles were carried out on preclinical models (primary cell cultures and patient-derived xenografts) derived from patients with PDAC included in the PaCaOmics program (NCT01692873). The RNA-based stratification was tested in a monocentric cohort and validated in a multicentric cohort, both retrospectively collected from resected PDAC samples (67 and 368 patients, respectively). Forty-three (65%) and 203 (55%) patients received adjuvant gemcitabine in the monocentric and the multicentric cohorts, respectively. The relationships between predicted gemcitabine sensitivity and patients' overall survival (OS) and disease-free survival were investigated.
The GemPred RNA signature was derived from preclinical models, defining gemcitabine sensitive PDAC as GemPred+. Among the patients who received gemcitabine in the test and validation cohorts, the GemPred+ patients had a higher OS than GemPred− (P = 0.046 and P = 0.00216). In both cohorts, the GemPred stratification was not associated with OS among patients who did not receive gemcitabine. Among gemcitabine-treated patients, GemPred+ patients had significantly higher OS than the GemPred−: 91.3 months 95% confidence interval (CI): 61.2-not reached versus 33 months (95% CI: 24-35.2); hazard ratio 0.403 (95% CI: 0.221-0.735, P = 0.00216). The interaction test for gemcitabine and GemPred+ stratification was significant (P = 0.0245). Multivariate analysis in the gemcitabine-treated population retained an independent predictive value.
The RNA-based GemPred stratification predicts the benefit of adjuvant gemcitabine in PDAC patients.
•An RNA signature of gemcitabine-sensitivity is developed from in vitro and in vivo models of pancreatic cancer.•The resulting GemPred signature identifies a subgroup of patients who are sensitive to adjuvant gemcitabine.•The predictive value of GemPred is validated in two cohorts on both OS and disease-free survival.
One strategy to improve therapies in advanced prostate cancer (PC) involves targeting genes that are activated by androgen withdrawal to delay the emergence of the androgen-independent (AI) ...phenotype. Heat shock protein 27 (Hsp27) expression becomes highly upregulated in PC cells after androgen withdrawal or chemotherapy, in which it functions as a cytoprotective chaperone to confer broad-spectrum treatment resistance. The purpose of this study is to elucidate anti-apoptotic pathways regulated by Hsp27 that are activated during PC progression. Using two-hybrid experiment, we found that Hsp27 was having a major role in the protein translational initiation process. Furthermore, using complementary DNA (cDNA) microarray analysis, 4E binding protein 1 was identified as being proportionately and highly regulated by Hsp27. These data led us to analyze the protein synthesis initiation pathway, which is a prerequisite for cell growth and proliferation. Using northern and western blot analysis, we found that Hsp27 downregulation decreased eukaryotic translation initiation factor 4E (eIF4E) expression at the protein, but not mRNA, level. The cytoprotection afforded by Hsp27 overexpression was attenuated by eIF4E knockdown using specific eIF4E short interfering RNA (siRNA). Co-immunoprecipitation and co-immunofluorescence confirmed that Hsp27 colocalizes and interacts directly with eIF4E. Hsp27-eIF4E interaction decreases eIF4E ubiquitination and proteasomal degradation. By chaperoning eIF4E, Hsp27 seems to protect the protein synthesis initiation process to enhance cell survival during cell stress induced by castration or chemotherapy. Forced overexpression of eIF4E induces resistance to androgen-withdrawal and paclitaxel treatment in the prostate LNCaP cells in vitro. These findings identify Hsp27 as a modulator of eIF4E and establish a potential mechanism for the eIF4E-regulated apoptosis after androgen ablation and chemotherapy. Targeting Hsp27-eIF4E interaction may serve as a therapeutic target in advanced PC.
Flavones represent a class of polyphenols that are found in many plant-derived food sources. Herein, we provide evidence that the anti-inflammatory and antiproliferative effect of the flavone ...apigenin relies on the regulation of the gut microbiota by the NOD-like receptor family pyrin domain containing 6 (Nlrp6). When challenged by dextran sulfate sodium (DSS) in drinking water, mice were protected against colitis upon cohousing with apigenin-treated animals. In contrast, the protective effect was lost in the absence of Nlrp6. Sequencing of the 16S ribosomal RNA gene revealed a shift in the composition of the gut microbiota in apigenin-treated mice that was not observed in the absence of Nlrp6. Equally important, we find that the antiproliferative effect of apigenin was dominantly transmitted after cohousing, while being compromised in Nlrp6-deficient mice. In contrast, the symptoms of colitis were alleviated upon apigenin administration even in the absence of either caspase-1/11 or Asc. Collectively, these data indicate that apigenin modulated an inflammasome-independent mechanism by which Nlrp6 reprograms the gut microbiota for protecting mice against colitis. Our study highlights a modulation of the Nlrp6 signaling pathway by a prominent constituent of the human diet that may point toward improved ways to treat inflammatory bowel diseases.
Sorafenib, an oral multikinase inhibitor, is the only approved agent for the treatment of advanced hepatocellular carcinoma (HCC). However, its benefits are modest, and as its mechanisms of action ...remain elusive, a better understanding of its anticancer effects is needed. Based on our previous study results, we investigated here the implication of the nuclear protein 1 (NUPR1) in HCC and its role in sorafenib treatment. NUPR1 is a stress-inducible protein that is overexpressed in various malignancies, but its role in HCC is not yet fully understood. We found that NUPR1 expression was significantly higher in primary human HCC samples than in the normal liver. Knockdown of NUPR1 significantly increased cell sensitivity to sorafenib and inhibited the cell growth, migration and invasion of HCC cells, both in vitro and in vivo. Moreover, NUPR1 silencing influenced the expression of RELB and IER3 genes. Unsurprisingly, RELB and IER3 knockdown also inhibited HCC cell viability, growth and migration. Using gene expression profiling of HCC cells following stable NUPR1 knockdown, we found that genes functionally involved in cell death and survival, cellular response to therapies, lipid metabolism, cell growth and proliferation, molecular transport and cellular movement were mostly suppressed. Network analysis of dynamic gene expression identified NF-κB and ERK as downregulated gene nodes, and several HCC-related oncogenes were also suppressed. We identified Runt-related transcription factor 2 (RUNX2) gene as a NUPR1-regulated gene and demonstrated that RUNX2 gene silencing inhibits HCC cell viability, growth, migration and increased cell sensitivity to sorafenib. We propose that the NUPR1/RELB/IER3/RUNX2 pathway has a pivotal role in hepatocarcinogenesis. The identification of the NUPR1/RELB/IER3/RUNX2 pathway as a potential therapeutic target may contribute to the development of new treatment strategies for HCC management.
TP53INP1 (tumor protein 53-induced nuclear protein 1) is a tumor suppressor, whose expression is downregulated in cancers from different organs. It was described as a p53 target gene involved in cell ...death, cell-cycle arrest and cellular migration. In this work, we show that TP53INP1 is also able to interact with ATG8-family proteins and to induce autophagy-dependent cell death. In agreement with this finding, we observe that TP53INP1, which is mainly nuclear, relocalizes in autophagosomes during autophagy where it is eventually degraded. TP53INP1-LC3 interaction occurs via a functional LC3-interacting region (LIR). Inactivating mutations of this sequence abolish TP53INP1-LC3 interaction, relocalize TP53INP1 in autophagosomes and decrease TP53INP1 ability to trigger cell death. Interestingly, TP53INP1 binds to ATG8-family proteins with higher affinity than p62, suggesting that it could partially displace p62 from autophagosomes, modifying thereby their composition. Moreover, silencing the expression of autophagy related genes (ATG5 or Beclin-1) or inhibiting caspase activity significantly decreases cell death induced by TP53INP1. These data indicate that cell death observed after TP53INP1-LC3 interaction depends on both autophagy and caspase activity. We conclude that TP53INP1 could act as a tumor suppressor by inducing cell death by caspase-dependent autophagy.
Tumor Protein p53-Induced Nuclear Protein 1 (TP53INP1) is a tumor suppressor that modulates the p53 response to stress. TP53INP1 is one of the key mediators of p53 antioxidant function by promoting ...the p53 transcriptional activity on its target genes. TP53INP1 expression is deregulated in many types of cancers including pancreatic ductal adenocarcinoma in which its decrease occurs early during the preneoplastic development. In this work, we report that redox-dependent induction of p53 transcriptional activity is enhanced by the oxidative stress-induced SUMOylation of TP53INP1 at lysine 113. This SUMOylation is mediated by PIAS3 and CBX4, two SUMO ligases especially related to the p53 activation upon DNA damage. Importantly, this modification is reversed by three SUMO1-specific proteases SENP1, 2 and 6. Moreover, TP53INP1 SUMOylation induces its binding to p53 in the nucleus under oxidative stress conditions. TP53INP1 mutation at lysine 113 prevents the pro-apoptotic, antiproliferative and antioxidant effects of TP53INP1 by impairing the p53 response on its target genes p21, Bax and PUMA. We conclude that TP53INP1 SUMOylation is essential for the regulation of p53 activity induced by oxidative stress.
Introduction L’expression du gène de l’insuline (INS) est finement régulée dans la cellule beta par nombre de facteurs de transcription. Récemment, des mutations homozygotes récessives situées dans ...le promoteur de INS ont été décrites chez des patients atteints de diabète néonatal (DN). Ces mutations entraîneraient une diminution de la biosynthèse d’insuline, mais les mécanismes moléculaires expliquant cela restaient énigmatiques. Notre but a été de comprendre quel mécanisme pouvait entraîner une diminution de la transcription de INS et in fine un DN. Patients et méthodes Nous avons séquencé le promoteur proximal de INS chez six patients avec DN, issus de familles consanguines et négatifs pour les causes principales de DN. La mutation identifiée a été étudiée sur les plans génétique (séquençage de contrôles), clinique (exploration métabolique des patients mutés) et cellulaire (gène-rapporteur, retard sur gel EMSA, immunoprécipitation de la chromatine ChIP). Un modèle animal a aussi été exploré. Résultats Nous avons identifié une mutation homozygote (c.-331C>G) chez deux patients turques, qui n’était pas présente chez 355 et 747 sujets contrôles d’origines française et turque, respectivement. Cette mutation touche un site de fixation putatif des facteurs KLF (Krüppel-Like Factors). En utilisant des gènes-rapporteurs afin de tester quel(s) KLF(s) activai(en)t le promoteur sauvage de INS mais pas le muté, nous avons trouvé que KLF11 est l’activateur du site. En outre, nous avons montré par ChIP/EMSA que KLF11 lie bien le site sauvage mais pas le site muté, et donc ne peut activer la transcription de INS. Enfin, des souris invalidées pour KLF11 montrent une altération franche de leur biosynthèse d’insuline. Conclusion La mutation identifiée altère l’activation du promoteur de INS par KLF11 et entraîne un DN. Nous avions montré précédemment que deux mutations dans KLF11 pouvaient causer un MODY. Ainsi, la voie de KLF11 joue un rôle clef dans la biosynthèse d’insuline et dans différentes formes de diabète.
After surgical resection of pancreatic ductal adenocarcinoma (PDAC), patients are predominantly treated with adjuvant chemotherapy, commonly consisting of gemcitabine (GEM)-based regimens or the ...modified FOLFIRINOX (mFFX) regimen. While mFFX regimen has been shown to be more effective than GEM-based regimens, it is also associated with higher toxicity. Current treatment decisions are based on patient performance status rather than on the molecular characteristics of the tumor. To address this gap, the goal of this study was to develop drug-specific transcriptomic signatures for personalized chemotherapy treatment.
We used PDAC datasets from preclinical models, encompassing chemotherapy response profiles for the mFFX regimen components. From them we identified specific gene transcripts associated with chemotherapy response. Three transcriptomic artificial intelligence signatures were obtained by combining independent component analysis and the least absolute shrinkage and selection operator-random forest approach. We integrated a previously developed GEM signature with three newly developed ones. The machine learning strategy employed to enhance these signatures incorporates transcriptomic features from the tumor microenvironment, leading to the development of the ‘Pancreas-View’ tool ultimately clinically validated in a cohort of 343 patients from the PRODIGE-24/CCTG PA6 trial.
Patients who were predicted to be sensitive to the administered drugs (n = 164; 47.8%) had longer disease-free survival (DFS) than the other patients. The median DFS in the mFFX-sensitive group treated with mFFX was 50.0 months stratified hazard ratio (HR) 0.31, 95% confidence interval (CI) 0.21-0.44, P < 0.001 and 33.7 months (stratified HR 0.40, 95% CI 0.17-0.59, P < 0.001) in the GEM-sensitive group when treated with GEM. Comparatively patients with signature predictions unmatched with the treatments (n = 86; 25.1%) or those resistant to all drugs (n = 93; 27.1%) had shorter DFS (10.6 and 10.8 months, respectively).
This study presents a transcriptome-based tool that was developed using preclinical models and machine learning to accurately predict sensitivity to mFFX and GEM.
•Transcriptomic signatures were developed for key pancreatic cancer drugs to enable personalized treatment.•The Pancreas-View tool integrates four drug signatures to assist informed therapeutic decisions.•Signatures accurately identify high responder patients, indicative of improved DFS and cancer-specific survival.•Clinical validation involving a cohort of 343 patients confirms the efficacy of this signature approach.•Transcriptomic signatures that integrate predictors from preclinical models and machine learning offer a rationalized treatment strategy.
Despite many advances in oncology, almost all patients with pancreatic cancer (PC) die of the disease. Molecularly targeted agents are offering hope for their potential role in helping translate the ...improved activity of combination chemotherapy into improved survival. Heat shock protein 27 (Hsp27) is a chaperone implicated in several pathological processes such as cancer. Further, Hsp27 expression becomes highly upregulated in cancer cells after chemotherapy. Recently, a modified antisense oligonucleotide that is complementary to Hsp27 (OGX-427) has been developed, which inhibits Hsp27 expression and enhances drug efficacy in cancer xenograft models. Phase II clinical trials using OGX-427 in different cancers like breast, ovarian, bladder, prostate and lung are in progress in the United States and Canada. In this study, we demonstrate using TMA of 181 patients that Hsp27 expression and phosphorylation levels increase in moderately differentiated tumors to become uniformly highly expressed in metastatic samples. Using MiaPaCa-2 cells grown both in vitro and xenografted in mice, we demonstrate that OGX-427 inhibits proliferation, induces apoptosis and also enhances gemcitabine chemosensitivity via a mechanism involving the eukaryotic translation initiation factor 4E. Collectively, these findings suggest that the combination of Hsp27 knockdown with OGX-427 and chemotherapeutic agents such as gemcitabine can be a novel strategy to inhibit the progression of pancreas cancer.
Malgré les énormes progrès réalisés dans la compréhension de l’étiologie du cancer et des percées significatives en matière de traitement, à ce jour la rémission complète n’est atteinte que dans ...environ la moitié des patients. En effet, des approches thérapeutiques couronnées de succès pour certains cancers s’avèrent totalement inefficaces pour d’autres, et certains types de cancers restent encore incurables. Afin de développer de nouvelles thérapies adaptées pour ces cancers récalcitrants, il est nécessaire de renouveler notre façon de voir le cancer et peut-être de revenir sur des paradigmes et des « faux amis » qui peuvent en réalité cacher de nouvelles cibles thérapeutiques. Un bon exemple de ces paradigmes concerne le rôle de la réponse au stress cellulaire dans la progression tumorale. En effet, nombre de recherches ont été consacrées au rôle prépondérant de certains acteurs de cette réponse dans la suppression de tumeur, l’exemple majeur étant la protéine p53. Néanmoins, lors de la progression tumorale et la formation de métastases, la cellule cancéreuse fait face à de nombreuses contraintes infligées par le microenvironnement tumoral, auxquelles elle ne peut s’adapter qu’à condition d’engager une réponse au stress efficace. Cette revue est consacrée au rôle joué par un des acteurs de la réponse au stress cellulaire, la protéine de stress p8, au cours de la carcinogenèse, en récapitulant les données disponibles à ce jour sur ses différentes fonctions et les atouts qu’elle confère à la cellule cancéreuse dans sa croissance, la résistance aux traitements et la formation de métastases.
In spite of the great advances made on the knowledge of cancer etiology and the significant breakthroughs in terms of treatment, complete remission is obtained in only around half of cancer patients. In fact, therapies that appear successful for some cancers are totally unfruitful for others, and some cancer types still remain incurables. In order to develop new therapies suitable to these tenacious cancers, we need to renew our view on cancer and to revise some old paradigms and “false friends” that can hide unexpected new therapeutic targets. A good example of these paradigms is the role of the cell stress response in tumor progression. Indeed, a number of studies has been devoted to the pivotal tumor suppressor function of some players of this response, of which the p53 protein is the best example. Nevertheless, during tumor progression and metastasis, the cancer cell faces many stresses imposed by tumor microenvironment and its survival will be conditioned by an efficient cell stress response. This review is consecrated to the role played by a pivotal actor of the cell stress response, the p8 protein, during carcinogenesis. We will recapitulate the data available on its different cell functions and the assets p8 confer to the cancer cell in terms of growth, drugs resistance and metastasis formations.
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