Cindy Neuzillet

Targeting the TGFβ pathway for cancer therapy.

The TGFβ signaling pathway has pleiotropic functions regulating cell growth, differentiation, apoptosis, motility and invasion, extracellular matrix production, angiogenesis, and immune response. TGFβ signaling deregulation is frequent in tumors and has crucial roles in tumor initiation, development and metastasis. TGFβ signaling inhibition is an emerging strategy for cancer therapy. The role of the TGFβ pathway as a tumor-promoter or suppressor at the cancer cell level is still a matter of debate, due to its differential effects at the early and late stages of carcinogenesis. In contrast, at the microenvironment level, the TGFβ pathway contributes to generate a favorable microenvironment for tumor growth and metastasis throughout all the steps of carcinogenesis. Then, targeting the TGFβ pathway in cancer may be considered primarily as a microenvironment-targeted strategy. In this review, we focus on the TGFβ pathway as a target for cancer therapy. In the first part, we provide a comprehensive overview of the roles played by this pathway and its deregulation in cancer, at the cancer cell and microenvironment levels. We go on to describe the preclinical and clinical results of pharmacological strategies to target the TGFβ pathway, with a highlight on the effects on tumor microenvironment. We then explore the perspectives to optimize TGFβ inhibition therapy in different tumor settings.

MEK in cancer and cancer therapy

The mitogen-activated extracellular signal-regulated kinase (MEK) pathway is one of the best-characterized kinase cascades in cancer cell biology. It is triggered by either growth factors or activating mutations of major oncogenic proteins in this pathway, the most common being Ras and Raf. Deregulation of this pathway is frequently observed and plays a central role in the carcinogenesis and maintenance of several cancers, including melanoma, pancreatic, lung, colorectal, and breast cancers. Targeting these kinases offers promise of novel therapies. MEK inhibitors (MEKi) are currently under evaluation in clinical trials and many have shown activity. In this review, we comprehensively examine the role of the MEK pathway in carcinogenesis and its therapeutic potential in cancer patients, with a focus on MEKi. We describe the clinical perspectives of MEKi in the two main models of Ras-ERK driven tumors, BRAF-mutant (addicted to the pathway) and KRAS-mutant (non-addicted). We also highlight the known mechanisms of resistance to MEKi and emerging strategies to overcome it.

Unraveling galectin-1 as a novel therapeutic target for cancer

Galectins belong to a family of carbohydrate-binding proteins with an affinity for β-galactosides. Galectin-1 is differentially expressed by various normal and pathologic tissues and displays a wide range of biological activities. In oncology, galectin-1 plays a pivotal role in tumor growth and in the multistep process of invasion, angiogenesis, and metastasis. Evidence indicates that galectin-1 exerts a variety of functions at different steps of tumor progression. Moreover, it has been demonstrated that galectin-1 cellular localization and galectin-1 binding partners depend on tumor localization and stage. Recently, galectin-1 overexpression has been extensively documented in several tumor types and/or in the stroma of cancer cells. Its expression is thought to reflect tumor aggressiveness in several tumor types. Galectin-1 has been identified as a promising drug target using synthetic and natural inhibitors. Preclinical data suggest that galectin-1 inhibition may lead to direct antiproliferative effects in cancer cells as well as antiangiogenic effects in tumors. We provide an up-to-date overview of available data on the role of galectin-1 in different molecular and biochemical pathways involved in human malignancies. One of the major challenges faced in targeting galectin-1 is the translation of current knowledge into the design and development of effective galectin-1 inhibitors in cancer therapy.

State of the art and future directions of pancreatic ductal adenocarcinoma therapy

Pancreatic ductal adenocarcinoma (PDAC) is expected to become the second cause of cancer-related death in 2030. PDAC is the poorest prognostic tumor of the digestive tract, with 80% of patients having advanced disease at diagnosis and 5-year survival rate not exceeding 7%. Until 2010, gemcitabine was the only validated therapy for advanced PDAC with a modest improvement in median overall survival as compared to best supportive care (5-6 vs 3 months). Multiple phase II-III studies have used various combinations of gemcitabine with other cytotoxics or targeted agents, most in vain, in attempt to improve this outcome. Over the past few years, the landscape of PDAC management has undergone major and rapid changes with the approval of the FOLFIRINOX and gemcitabine plus nab-paclitaxel regimens in patients with metastatic disease. These two active combination chemotherapy options yield an improved median overall survival (11.1 vs 8.5 months, respectively) thus making longer survival a reasonably achievable goal. This breakthrough raises some new clinical questions about the management of PDAC. Moreover, better knowledge of the environmental and genetic events that underpin multistep carcinogenesis and of the microenvironment surrounding cancer cells in PDAC has open new perspectives and therapeutic opportunities. In this new dynamic context of deep transformation in basic research and clinical management aspects of the disease, we gathered updated preclinical and clinical data in a multifaceted review encompassing the lessons learned from the past, the yet unanswered questions, and the most promising research priorities to be addressed for the next 5 years.

High c-Met expression in stage I-II pancreatic adenocarcinoma: proposal for an immunostaining scoring method and correlation with poor prognosis.

AIMSnc-Met is an emerging biomarker in pancreatic ductal adenocarcinoma (PDAC); there is no consensus regarding the immunostaining scoring method for this marker. We aimed to assess the prognostic value of c-Met overexpression in resected PDAC, and to elaborate a robust and reproducible scoring method for c-Met immunostaining in this setting.nnnMETHODS AND RESULTSnc-Met immunostaining was graded according to the validated MetMab score, a classic visual scale combining surface and intensity (SI score), or a simplified score (high c-Met: ≥ 20% of tumour cells with strong membranous staining), in stage I-II PDAC. A computer-assisted classification method (Aperio software) was developed. Clinicopathological parameters were correlated with disease-free survival (DFS) and overall survival(OS). One hundred and forty-nine patients were analysed retrospectively in a two-step process. Thirty-seven samples (whole slides) were analysed as a pre-run test. Reproducibility values were optimal with the simplified score (kappa = 0.773); high c-Met expression (7/37) was associated with shorter DFS [hazard ratio (HR) 3.456, P = 0.0036] and OS (HR 4.257, P = 0.0004). c-Met expression was concordant on whole slides and tissue microarrays in 87.9% of samples, and quantifiable with a specific computer-assisted algorithm. In the whole cohort (n = 131), patients with c-Met(high) tumours (36/131) had significantly shorter DFS (9.3 versus 20.0 months, HR 2.165, P = 0.0005) and OS (18.2 versus 35.0 months, HR 1.832, P = 0.0098) in univariate and multivariate analysis.nnnCONCLUSIONSnSimplified c-Met expression is an independent prognostic marker in stage I-II PDAC that may help to identify patients with a high risk of tumour relapse and poor survival.

Difficult diagnosis of atypical cystic pancreatic lesions in von Hippel-Lindau disease.

von Hippel-Lindau disease is a progressive, autosomal dominant disorder with multiorgan involvement. There are 2 types of pancreatic lesions from von Hippel-Lindau disease: cystic lesions and endocrine pancreatic tumors. Only the latter type is potentially malignant and may justify pancreatic resection. The differential diagnosis between these 2 types of lesions can be difficult. We report 3 patients with atypical cystic pancreatic lesions who underwent surgery for suspected malignant tumors. The pathological-radiological correlations and the diagnostic and management strategies are discussed.

Disease control with sunitinib in advanced intrahepatic cholangiocarcinoma resistant to gemcitabine-oxaliplatin chemotherapy.

Advanced cholangiocarcinoma is associated with poor prognostic survival and has limited therapeutic options available at present. The importance of angiogenesis and expression of pro-angiogenic factors in intrahepatic forms of cholangiocarcinoma suggest that therapies targeting angiogenesis might be useful for the treatment of this disease. Here we report three cases of patients with advanced intrahepatic cholangiocarcinoma progressive after standard chemotherapy and treated with sunitinib 50 mg/d in 6-wk cycles of 4 wk on treatment followed by 2 wk off treatment (Schedule 4/2). In all three patients, sunitinib treatment was associated with a sustained disease control superior to 4 mo, patients achieving either a partial response or stable disease. A reduction in tumor size and density was observed in all cases, suggesting tumor necrosis as a result of sunitinib treatment in these patients. In addition, sunitinib was generally well tolerated and the occurrence of side effects was managed with standard medical interventions, as required. Our results suggest that sunitinib therapy may be associated with favorable outcomes and tolerability in patients with advanced cholangiocarcinoma. Those observations contributed to launch a prospective phase II multicenter trial investigating sunitinib in advanced intrahepatic cholangiocarcinoma (SUN-CK study; NCT01718327).

Aspects moléculaires du cancer du pancréas : évolutions et révolutions ?

Pendant deux decennies, la gemcitabine a ete le standard therapeutique de l’adenocarcinome du pancreas (AP) avance. Depuis 2011, des avancees notables ont ete realisees avec l’avenement de combinaisons de chimiotherapies plus efficaces, avec le FOLFIRINOX (combinant 5-FU, irinotecan et oxaliplatine) et l’association gemcitabine plus nab-paclitaxel. En depit de ces progres, l’arsenal therapeutique de l’AP reste limiteet l’avenement de nouveaux traitements et strategies therapeutiques constitue un enjeu medical majeur. La plupart des therapies dites « ciblees », reconnues efficaces dans d’autres localisations tumorales, se sont revelees decevantes dans le traitement de l’AP. Une meilleure comprehension des mecanismes moleculaires de la carcinogenese pancreatique et de son microenvironnement a conduit a de nouveaux concepts et options therapeutiques innovantes. Cette revue fait l’etat de ces evolutions (et revolutions ?) dans le traitement medical de l’AP.

Quel futur à 5 ans pour le traitement médical des cancers du pancréas

Pendant deux decennies, la gemcitabine a occupe la position de standard therapeutique du traitement medical de l’adenocarcinome du pancreas (AP) avance. Depuis 2011, des avancees notables ont ete enregistrees avec la mise a disposition de combinaisons de chimiotherapies plus efficaces, le FOLFIRINOX (combinant 5-FU, irinotecan et oxaliplatine) et l’association gemcitabine plus nab-paclitaxel. En depit de ces progres, l’arsenal therapeutique reste limiteet l’avenement de nouveaux traitements et strategies therapeutiques constitue un enjeu medical majeur. La plupart des therapies dites « ciblees », reconnues efficaces dans d’autres localisations tumorales, se sont revelees decevantes dans le traitement de l’AP. Une meilleure comprehension des mecanismes moleculaires et cellulaires de la carcinogenese pancreatique et de son microenvironnement a conduit a de nouveaux concepts et options therapeutiques alternatives, parfois prometteuses. Certaines d’entre elles ont deja debouche sur des resultats concrets. Cette revue fait l’etat de ces avancees et tente de degager le futur a cinq ans du traitement medical de l’AP.

Abstract 221: Ex vivo cultures of freshly explanted tumors: a potent translational approach for screening novel targeted agents

Background: In vitro and in vivo models are important screening tools for novel anticancer agents but they do not reliably reflect the complexity of human tumors and are, by essence, incapable of evaluating the intricate interplay of cancer cells in their native stroma. We used a novel approach using freshly explanted human tumor slices to test the pharmacodynamic effects of targeted agents or combination therapies. Materials and Methods: Tumor samples were obtained from fresh surgical specimens cut in 300 μm thick slices using a Leica microtome and maintained in culture for 24-72 hours in a defined environment that allows for diffusion of oxygen and nutrient in specific culture media. Tumor samples were analyzed by immunohistochemistry and immunofluorescence for various pharmacodynamics (PD) biomarkers. Results: The first step was to establish the suitable conditions for ex vivo culture, by comparing several O2 levels and medium composition. Tissue quality and viability controls were more reliably assessed by HE staining than by MTT and LDH assays. In our study, 60% of the samples had >80% viable cancer lesions. Thirteen ex vivo hepatocellular tumor explants were treated with the TGF-β inhibitor galunisertib or sorafenib as control. Galunisertib specific target engagement was evaluated by p-SMAD2/3 expression. We showed a significant decrease in p-SMAD2/3 expression after galunisertib exposure that was mostly unchanged after sorafenib treatment. Expression of the non specific early PD biomarkers pAKT and pERK were decreased in 60% and 90% of the samples treated with galunisertib and sorafenib respectively. Expression of the late PD biomarkers MIB1/Ki67 was decreased in 54% and 77% of the samples whereas expression of caspase-3 was increased in 54% and 62% of the samples treated with galunisertib and sorafenib, respectively. Combination of galunisertib and sorafenib exacerbated the results observed using p-SMAD2/3 expression and early PD biomarkers but not those observed using late PD biomarkers. In twelve head and neck tumors, target engagement for SMAC mimetic treatment was evaluated by c-IAP1 expression using cisplatin and carboplatin as controls. We showed a significant decrease in c-IAP1 expression in all samples after exposure to SMAC mimetic. For both mono and combination therapies, we evaluated expression of MIB1 and caspase-3 as well as necrosis as late PD biomarkers. We observed a stronger effect of the SMAC mimetic/cisplatin combination in inducing necrosis (92% vs 70%) whereas the SMAC mimetic/carboplatin combination was more efficient in inducing caspase-3 expression (90% vs 83%). Both combinations displayed similar effect on reducing MIB1 expression. Conclusion: Ex vivo culture of fresh tumor explants is a valuable tool to assess the pharmacodynamic effects of anticancer agents in tumors and may contribute to evaluate drug effects in the perspective of predictive medicine. Citation Format: Annemilai Tijeras-Raballand, Maria Serova, Cindy Neuzillet, Miguel Albuquerque, Nathalie Colnot, Pierre Bourgoin, Safi Dokmak, Mohamed Bouattour, Jacques Belghiti, Valerie Paradis, Eric Raymond, Sandrine Faivre, Armand de Gramont. Ex vivo cultures of freshly explanted tumors: a potent translational approach for screening novel targeted agents. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 221. doi:10.1158/1538-7445.AM2015-221