Daniel Pietrasz

Cancer-associated fibroblast-derived annexin A6 + extracellular vesicles support pancreatic cancer aggressiveness

The intratumoral microenvironment, or stroma, is of major importance in the pathobiology of pancreatic ductal adenocarcinoma (PDA), and specific conditions in the stroma may promote increased cancer aggressiveness. We hypothesized that this heterogeneous and evolving compartment drastically influences tumor cell abilities, which in turn influences PDA aggressiveness through crosstalk that is mediated by extracellular vesicles (EVs). Here, we have analyzed the PDA proteomic stromal signature and identified a contribution of the annexin A6/LDL receptor-related protein 1/thrombospondin 1 (ANXA6/LRP1/TSP1) complex in tumor cell crosstalk. Formation of the ANXA6/LRP1/TSP1 complex was restricted to cancer-associated fibroblasts (CAFs) and required physiopathologic culture conditions that improved tumor cell survival and migration. Increased PDA aggressiveness was dependent on tumor cell-mediated uptake of CAF-derived ANXA6+ EVs carrying the ANXA6/LRP1/TSP1 complex. Depletion of ANXA6 in CAFs impaired complex formation and subsequently impaired PDA and metastasis occurrence, while injection of CAF-derived ANXA6+ EVs enhanced tumorigenesis. We found that the presence of ANXA6+ EVs in serum was restricted to PDA patients and represents a potential biomarker for PDA grade. These findings suggest that CAF-tumor cell crosstalk supported by ANXA6+ EVs is predictive of PDA aggressiveness, highlighting a therapeutic target and potential biomarker for PDA.

Plasma Circulating Tumor DNA in Pancreatic Cancer Patients Is a Prognostic Marker

Purpose: Despite recent therapeutic advances, prognosis of patients with pancreatic adenocarcinoma remains poor. Analyses from tumor tissues present limitations; identification of informative marker from blood might be a promising alternative. The aim of this study was to assess the feasibility and the prognostic value of circulating tumor DNA (ctDNA) in pancreatic adenocarcinoma. Experimental Design: From 2011 to 2015, blood samples were prospectively collected from all consecutive patients with pancreatic adenocarcinoma treated in our center. Identification of ctDNA was done with next-generation sequencing targeted on referenced mutations in pancreatic adenocarcinoma and with picoliter droplet digital PCR. Results: A total of 135 patients with resectable (n = 31; 23%), locally advanced (n = 36; 27%), or metastatic (n = 68; 50%) pancreatic adenocarcinoma were included. In patients with advanced pancreatic adenocarcinoma (n = 104), 48% (n = 50) had ctDNA detectable with a median mutation allelic frequency (MAF) of 6.1%. The presence of ctDNA was strongly correlated with poor overall survival (OS; 6.5 vs. 19.0 months; P < 0.001) in univariate and multivariate analyses (HR = 1.96; P = 0.007). To evaluate the impact of ctDNA level, patients were grouped according to MAF tertiles: OS were 18.9, 7.8, and 4.9 months (P < 0.001). Among patients who had curative intent resection (n = 31), 6 had ctDNA detectable after surgery, with an MAF of 4.4%. The presence of ctDNA was associated with a shorter disease-free survival (4.6 vs.17.6 months; P = 0.03) and shorter OS (19.3 vs. 32.2 months; P = 0.027). Conclusions: ctDNA is an independent prognostic marker in advanced pancreatic adenocarcinoma. Furthermore, it arises as an indicator of shorter disease-free survival in resected patients when detected after surgery. Clin Cancer Res; 23(1); 116–23. ©2016 AACR.

SynthèseQuel avenir pour l’ADN tumoral circulant ? État des lieux et perspectives dans les cancers colorectaux, pulmonaires non à petites cellules et pancréatiquesWhat future for circulating tumor DNA? Current data and prospects in colorectal, non-small cell lung and pancreatic cancers

Ten years after the discovery of the predictive value of KRAS status for anti-EGFR antibodies, other genes involved in oncogenesis and therapeutic responses were identified and are now systematically sought. Molecular diagnosis often requires invasive procedures, sometimes iatrogenic, and is limited by feasibility problems, quantity and quality of samples. Identifying these mutations from blood biomarkers would reduce costs and diagnostic delay. The circulating tumor DNA (ctDNA) is one of the most promising blood biomarkers. In this review, we report and discuss the latest results obtained with ctDNA in colorectal cancer, non-small cell lung cancer, and adenocarcinoma of the pancreas. If the methods highlighting appear very heterogeneous, the correlation between mutations found in tumor and those identified in the blood exceeds 95 % specificity in numerous studies. The detection sensitivity is in turn strongly related to tumor stage patients. The presence of ctDNA appears as a prognostic factor for progression-free survival and overall survival. Finally, recent studies have shown that the changing rate ctDNA during systemic treatments had a predictive value for therapeutic efficacy. These results allow to consider the use of ctDNA in monitoring patients to identify early recurrence or progression.

Quel avenir pour l’ADN tumoral circulant ? État des lieux et perspectives dans les cancers colorectaux, pulmonaires non à petites cellules et pancréatiques

Ten years after the discovery of the predictive value of KRAS status for anti-EGFR antibodies, other genes involved in oncogenesis and therapeutic responses were identified and are now systematically sought. Molecular diagnosis often requires invasive procedures, sometimes iatrogenic, and is limited by feasibility problems, quantity and quality of samples. Identifying these mutations from blood biomarkers would reduce costs and diagnostic delay. The circulating tumor DNA (ctDNA) is one of the most promising blood biomarkers. In this review, we report and discuss the latest results obtained with ctDNA in colorectal cancer, non-small cell lung cancer, and adenocarcinoma of the pancreas. If the methods highlighting appear very heterogeneous, the correlation between mutations found in tumor and those identified in the blood exceeds 95 % specificity in numerous studies. The detection sensitivity is in turn strongly related to tumor stage patients. The presence of ctDNA appears as a prognostic factor for progression-free survival and overall survival. Finally, recent studies have shown that the changing rate ctDNA during systemic treatments had a predictive value for therapeutic efficacy. These results allow to consider the use of ctDNA in monitoring patients to identify early recurrence or progression.

LIF drives neural remodeling in pancreatic cancer and offers a new candidate biomarker

Pancreatic ductal adenocarcinoma (PDAC) is characterized by extensive stroma and pathogenic modifications to the peripheral nervous system that elevate metastatic capacity. In this study, we show that the IL6-related stem cell-promoting factor LIF supports PDAC-associated neural remodeling (PANR). LIF was overexpressed in tumor tissue compared with healthy pancreas, but its receptors LIFR and gp130 were expressed only in intratumoral nerves. Cancer cells and stromal cells in PDAC tissues both expressed LIF, but only stromal cells could secrete it. Biological investigations showed that LIF promoted the differentiation of glial nerve sheath Schwann cells and induced their migration by activating JAK/STAT3/AKT signaling. LIF also induced neuronal plasticity in dorsal root ganglia neurons by increasing the number of neurites and the soma area. Notably, injection of LIF-blocking antibody into PDAC-bearing mice reduced intratumoral nerve density, supporting a critical role for LIF function in PANR. In serum from human PDAC patients and mouse models of PDAC, we found that LIF titers positively correlated with intratumoral nerve density. Taken together, our findings suggest LIF as a candidate serum biomarker and diagnostic tool and a possible therapeutic target for limiting the impact of PANR in PDAC pathophysiology and metastatic progression.Significance: This study suggests a target to limit neural remodeling in pancreatic cancer, which contributes to poorer quality of life and heightened metastatic progression in patients. Cancer Res; 78(4); 909-21. ©2017 AACR.

Adénocarcinomes du pancréas borderline et localement avancés réséqués après chimiothérapie néo-adjuvante par Folfirinox : résultats d’une étude multicentrique AGEO/FRENCH

Objectif Evaluer les resultats de la resection chirurgicale d’adenocarcinome pancreatique (ADCP), borderline (BR) ou localement avance (LA) apres Folfirinox (FLX) en neo-adjuvant. Methodes Les patients (pts) operes apres FLX ont ete retrospectivement inclus dans cette etude multicentrique. Les tumeurs ont ete classees BR/LA selon la classification du MD Anderson. Resultats De novembre 2010 a decembre 2013, 77 pts (âge median 59 ans) ont ete inclus : 43 ADCP (56 %) classes BR et 34 (44 %) LA au diagnostic. La chirurgie etait realisee apres une mediane de 6 cycles (1–30) de FLX. 53 pts (69 %) ont recu une radiochimiotherapie (RCT) preoperatoire. 63 tumeurs (82 %) etaient cephaliques (taille moyenne 33mm [16–110]) et 26 (34 %) ont requis une resection vasculaire. 22 % des pts ont presente une complication classee Clavien III/IV. La mortalite post-operatoire a 2 mois etait de 2,6 % (2 deces). Le taux de resection R0 etait de 82 % (63/77), avec 16 % (12/77) de reponse histologique complete (RHC). Apres une duree mediane de suivi de 19 mois, 23 pts (30 %) ont presente une recidive tumorale, don’t 12 deces (16 %). La survie sans recidive et la survie globale etaient de 22,8 mois [IC 95 % : 18,5–27,1] et 39,5 mois [IC 95 % : 35,3–43,7]. Conclusion La resection chirurgicale pour ADCP BR/LA apres FLX semble sure, meme apres RCT. Le taux de resection R0 et de RHC suggere une evaluation prospective de cette strategie. Des donnees de suivi actualisees seront presentees durant l’AFC.