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Dive into the research topics where Jean-Christophe Vaillant is active.

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Featured researches published by Jean-Christophe Vaillant.


Gut | 2009

Identification of CD8+CD25+Foxp3+ suppressive T cells in colorectal cancer tissue

Nathalie Chaput; Samy Louafi; Armelle Bardier; Frédéric Charlotte; Jean-Christophe Vaillant; Fabrice Menegaux; Michelle Rosenzwajg; François M. Lemoine; David Klatzmann; Julien Taieb

Background: The antitumoral immune response is one determinant of colorectal cancer (CRC) outcome. Recent work suggests that Foxp3+CD25+CD4+ regulatory T cells (T4reg) might hamper effective immunosurveillance of emerging cancer cells and impede effective immune responses to established tumours. In this descriptive study, we analysed blood and tissue regulatory T cell populations in patients with CRC. Methods: Blood and tissue regulatory Foxp3+ T cells from 40 patients with CRC were compared to regulatory Foxp3+ T cells from normal colonic tissue and from blood of 26 healthy volunteers. Flow cytometry was used to quantify and phenotype all Foxp3+ T cell populations. Correlations were sought with the tumour stage and with micro-invasive status. The suppressive capacity of regulatory Foxp3+ T cells was assessed by their effect on CD4+CD25− T cell proliferation in vitro and by their capacity to inhibit cytokine production by conventional T cells. Results: We found a significant increase of CD8+CD25+Foxp3+ cells (T8reg) in blood and CRC tissue; their phenotype was close to that of T4reg. T8reg cells infiltrating CRC were activated, as suggested by increased cytoxic T lymphocyte-associated antigen-4, glucocorticoid-induced tumour necrosis factor-related protein, and transforming growth factor (TGF)β1 expression compared to T8reg from normal autologous colonic tissue. Moreover, T8reg were able to suppress CD4+CD25− T cell proliferation and Th1 cytokine production ex vivo, demonstrating that tumour-infiltrating T8reg have strong suppressive capacities. T8reg numbers correlated with the tumour stage and with micro-invasive status. Finally, interleukin 6 and TGFβ1 synergistically induced the generation of CD8+CD25+Foxp3+ T cells ex vivo. Conclusions: We have identified a new regulatory T cell population (CD8+Foxp3+) in colorectal tumours. After isolation from cancer tissue these CD8+Foxp3+ cells demonstrated strong immunosuppressive properties in vitro. These data suggest that these cells may contribute to tumoral immune escape and disease progression.


International Journal of Cancer | 2000

Vegf, vegf-B, vegf-C and their receptors KDR, FLT-1 and FLT-4 during the neoplastic progression of human colonic mucosa

Thierry André; Larissa Kotelevets; Jean-Christophe Vaillant; Anne Marie Coudray; Laurence Weber; Sophie Prevot; Roland Parc; Christian Gespach; Eric Chastre

Because the crucial role of angiogenesis has been demonstrated in tumor growth and metastasis, the present study was undertaken to characterize the relative expression of vascular endothelial growth factors VEGF (vascular endothelial growth factor), VEGF‐B, VEGF‐C, and their receptors KDR (kinase insert domain‐containing receptor), FLT‐1 (fms‐like tyrosine kinase), and FLT‐4 in human colonic cancers, in relation to the Astler‐Coller pathological classification, and to prognosis. VEGF and VEGF‐B gene expression was quantified by Northern blot in 72 tumor samples matched with control tissues. VEGF gene expression was 1.4 times higher in adenocarcinomas than in control tissues (p = 0.02), but did not increase further between Astler‐Coller tumor stages A and D, and did not correlate with disease recurrence for patients at stages B2 or C. In adenomas, VEGF mRNA levels were not significantly different from those in the paired control colonic mucosa. The expression pattern of VEGF isoforms, mainly identified by RT‐PCR (reverse‐transcriptase‐coupled polymerase chain reaction) as VEGF121 and VEGF165 and to a lesser extent VEGF189, was comparable in tumor and control tissues. VEGF‐B mRNA levels were unchanged during the neoplastic progression of colonic mucosa. In contrast to KDR and FLT‐4, the expression of VEGF‐C and FLT‐1 genes increased in some pathological tissues. These results provide evidence that the early and sustained increase in VEGF transcripts and the expression of multiple angiogenic factors and receptors contribute to the development of colon cancer, and thus constitute a putative target for anti‐angiogenic drug therapy. Int. J. Cancer 86:174–181, 2000.


Cell Host & Microbe | 2008

Scavenger Receptor BI Boosts Hepatocyte Permissiveness to Plasmodium Infection

Samir Yalaoui; Thierry Huby; Jean-François Franetich; Audrey Gego; Armelle Rametti; Martine Moreau; Xavier Collet; Anthony Siau; Geert-Jan van Gemert; Robert W. Sauerwein; Adrian J. F. Luty; Jean-Christophe Vaillant; Laurent Hannoun; John Wehrley Chapman; Dominique Mazier; Patrick Froissard

Infection of hepatocytes by Plasmodium falciparum sporozoites requires the host tetraspanin CD81. CD81 is also predicted to be a coreceptor, along with scavenger receptor BI (SR-BI), for hepatitis C virus. Using SR-BI-knockout, SR-BI-hypomorphic and SR-BI-transgenic primary hepatocytes, as well as specific SR-BI-blocking antibodies, we demonstrate that SR-BI significantly boosts hepatocyte permissiveness to P. falciparum, P. yoelii, and P. berghei entry and promotes parasite development. We show that SR-BI, but not the low-density lipoprotein receptor, acts as a major cholesterol provider that enhances Plasmodium infection. SR-BI regulates the organization of CD81 at the plasma membrane, mediating an arrangement that is highly permissive to penetration by sporozoites. Concomitantly, SR-BI upregulates the expression of the liver fatty-acid carrier L-FABP, a protein implicated in Plasmodium liver-stage maturation. These findings establish the mechanistic basis of the CD81-dependent Plasmodium sporozoite invasion pathway.


Annals of Surgery | 2000

Adjuvant intraperitoneal 5-fluorouracil in high-risk colon cancer: A multicenter phase III trial.

Jean-Christophe Vaillant; Bernard Nordlinger; Sylvie Deuffic; Jean-Pierre Arnaud; Edouard Pelissier; Jean-Pierre Favre; Daniel Jaeck; Gilles Fourtanier; Jean-Paul Grandjean; Philippe Marre; Christian Letoublon

OBJECTIVE To evaluate the results of a prospective multicenter randomized study of adjuvant intraperitoneal 5-fluorouracil (5-FU) administered during 6 days shortly after resection of stages II and III colon cancers. SUMMARY BACKGROUND DATA Systemic adjuvant chemotherapy improves the survival of patients with stage III colon cancer receiving treatment for 6 months. Intraperitoneal chemotherapy theoretically combines peritoneal and hepatic effects. METHODS After resection, 267 patients were randomized into two groups. Patients in group 1 (n = 133) underwent resection followed by intraperitoneal administration of 5-FU (0.6 g/m2/day) for 6 days (day 4 to day 10). These patients also received intravenous 5-FU (1 g) during surgery. Patients in group 2 underwent resection alone (n = 134). RESULTS In group 1, 103 patients received the total dose, 18 received a partial dose as a result of technical or tolerance problems, and 12 did not receive the chemotherapy. Rates of surgical death and complications were similar in both groups. Tolerance to treatment was excellent or fair in 97% of the patients and poor in 3%. After a median follow-up of 58 months, 5-year overall survival rates were 74% in group 1 and 69% in group 2; disease-free survival rates were 68% and 62%, respectively. Survival curves were superimposed until 3 years after treatment and began diverging thereafter. Among patients receiving the full treatment, the 5-year disease-free survival rate was improved in the treatment group in patients with stage II cancers but was unchanged in patients with stage III cancers. CONCLUSIONS Chemotherapy with intraperitoneal 5-FU administered during a short period after surgery was well tolerated but was not sufficient to reduce the risk of death significantly. However, it reduced the risk of recurrence in stage II cancers. These results suggest that it should be associated with systemic chemotherapy to reduce both local and distant recurrences.


Annals of Surgery | 2015

The impact of severe anastomotic leak on long-term survival and cancer recurrence after surgical resection for esophageal malignancy

Sheraz R. Markar; Caroline Gronnier; Alain Duhamel; Jean-Yves Mabrut; Jean-Pierre Bail; Nicolas Carrere; Jeremie H. Lefevre; Cécile Brigand; Jean-Christophe Vaillant; Mustapha Adham; Simon Msika; Nicolas Demartines; Issam El Nakadi; Bernard Meunier; Denis Collet; Christophe Mariette

Objective: The aim of this study was to the determine impact of severe esophageal anastomotic leak (SEAL) upon long-term survival and locoregional cancer recurrence. Background: The impact of SEAL upon long-term survival after esophageal resection remains inconclusive with a number of studies demonstrating conflicting results. Methods: A multicenter database for the surgical treatment of esophageal cancer collected data from 30 university hospitals (2000–2010). SEAL was defined as a Clavien-Dindo III or IV leak. Patients with SEAL were compared with those without in terms of demographics, tumor characteristics, surgical technique, morbidity, survival, and recurrence. Results: From a database of 2944 operated on for esophageal cancer between 2000 and 2010, 209 patients who died within 90 days of surgery and 296 patients with a R1/R2 resection were excluded, leaving 2439 included in the final analysis; 208 (8.5%) developed a SEAL and significant independent association was observed with low hospital procedural volume, cervical anastomosis, tumoral stage III/IV, and pulmonary and cardiovascular complications. SEAL was associated with a significant reduction in median overall (35.8 vs 54.8 months; P = 0.002) and disease-free (34 vs 47.9 months; P = 0.005) survivals. After adjustment of confounding factors, SEAL was associated with a 28% greater likelihood of death [hazard ratio = 1.28; 95% confidence interval (CI): 1.04–1.59; P = 0.022], as well as greater overall (OR = 1.35; 95% CI: 1.15–1.73; P = 0.011), locoregional (OR = 1.56; 95% CI: 1.05–2.24; P = 0.030), and mixed (OR = 1.81; 95% CI: 1.20–2.71; P = 0.014) recurrences. Conclusions: This large multicenter study provides strong evidence that SEAL adversely impacts cancer prognosis. The mechanism through which SEAL increases local recurrence is an important area for future research.


Annals of Oncology | 2012

Contribution of CXCR4 and SMAD4 in predicting disease progression pattern and benefit from adjuvant chemotherapy in resected pancreatic adenocarcinoma

Jean-Baptiste Bachet; Raphaël Maréchal; Pieter Demetter; Franck Bonnetain; Anne Couvelard; Magali Svrcek; Armelle Bardier-Dupas; Pascal Hammel; Alain Sauvanet; Christophe Louvet; François Paye; Philippe Rougier; Christophe Penna; Jean-Christophe Vaillant; Thierry André; Jean Closset; Isabelle Salmon; Jean-François Emile; J Van Laethem

BACKGROUND Prognosis of patients with pancreatic adenocarcinoma is poor. Many prognostic biomarkers have been tested, but most studies included heterogeneous patients. We aimed to investigate the prognostic and/or predictive values of four relevant biomarkers in a multicentric cohort of patients. PATIENTS AND METHODS A total of 471 patients who had resected pancreatic adenocarcinoma were included. Using tissue microarray, we assessed the relationship of biomarker expressions with the overall survival: Smad4, type II TGF-β receptor, CXCR4, and LKB1. RESULTS High CXCR4 expression was found to be the only independent negative prognostic biomarker [hazard ratio (HR)=1.74; P<0.0001]. In addition, it was significantly associated with a distant relapse pattern (HR=2.19; P<0.0001) and was the strongest prognostic factor compared with clinicopathological factors. In patients who did not received adjuvant treatment, there was a trend toward decrease in the overall survival for negative Smad4 expression. Loss of Smad4 expression was not correlated with recurrence pattern but was shown to be predictive for adjuvant chemotherapy (CT) benefit (HR=0.59; P=0.002). CONCLUSIONS CXCR4 is a strong independent prognostic biomarker associated with distant metastatic recurrence and appears as an attractive target to be evaluated in pancreatic adenocarcinoma. Negative SMAD4 expression should be considered as a potential predictor of adjuvant CT benefit.BACKGROUND Prognosis of patients with pancreatic adenocarcinoma is poor. Many prognostic biomarkers have been tested, but most studies included heterogeneous patients. We aimed to investigate the prognostic and/or predictive values of four relevant biomarkers in a multicentric cohort of patients. PATIENTS AND METHODS A total of 471 patients who had resected pancreatic adenocarcinoma were included. Using tissue microarray, we assessed the relationship of biomarker expressions with the overall survival: Smad4, type II TGF-β receptor, CXCR4, and LKB1. RESULTS High CXCR4 expression was found to be the only independent negative prognostic biomarker [hazard ratio (HR) = 1.74; P < 0.0001]. In addition, it was significantly associated with a distant relapse pattern (HR = 2.19; P < 0.0001) and was the strongest prognostic factor compared with clinicopathological factors. In patients who did not received adjuvant treatment, there was a trend toward decrease in the overall survival for negative Smad4 expression. Loss of Smad4 expression was not correlated with recurrence pattern but was shown to be predictive for adjuvant chemotherapy (CT) benefit (HR = 0.59; P = 0.002). CONCLUSIONS CXCR4 is a strong independent prognostic biomarker associated with distant metastatic recurrence and appears as an attractive target to be evaluated in pancreatic adenocarcinoma. Negative SMAD4 expression should be considered as a potential predictor of adjuvant CT benefit.


Annals of Surgery | 2014

Impact of neoadjuvant chemoradiotherapy on postoperative outcomes after esophageal cancer resection: results of a European multicenter study.

Caroline Gronnier; Boris B Tréchot; Alain Duhamel; Jean-Yves Mabrut; Jean-Pierre Bail; Nicolas Carrere; Jeremie H. Lefevre; Cécile Brigand; Jean-Christophe Vaillant; Mustapha Adham; Simon Msika; Nicolas Demartines; Issam El Nakadi; Guillaume Piessen; Bernard Meunier; Denis Collet; Christophe Mariette; Lucien Guillaume; Magalie Cabau; Jacques Jougon; Bogdan Badic; Patrick Lozach; Serge Cappeliez; Gil Lebreton; Arnaud Alves; Renaud Flamein; Denis Pezet; Federica Pipitone; Bogdan Stan Iuga; Nicolas Contival

Objectives:To assess the impact of neoadjuvant chemoradiotherapy (NCRT) on anastomotic leakage (AL) and other postoperative outcomes after esophageal cancer (EC) resection. Background:Conflicting data have emerged from randomized studies regarding the impact of NCRT on AL. Methods:Among 2944 consecutive patients operated on for EC between 2000 and 2010 in 30 European centers, patients treated by NCRT after surgery (n = 593) were compared with those treated by primary surgery (n = 1487). Multivariable analyses and propensity score matching were used to compensate for the differences in some baseline characteristics. Results:Patients in the NCRT group were younger, with a higher prevalence of male sex, malnutrition, advanced tumor stage, squamous cell carcinoma, and surgery after 2005 when compared with the primary surgery group. Postoperative AL rates were 8.8% versus 10.6% (P = 0.220), and 90-day postoperative mortality and morbidity rates were 9.3% versus 7.2% (P = 0.110) and 33.4% versus 32.1% (P = 0.564), respectively. Pulmonary complication rates did not differ between groups (24.6% vs 22.5%; P = 0.291), whereas chylothorax (2.5% vs 1.2%; P = 0.020), cardiovascular complications (8.6% vs 0.1%; P = 0.037), and thromboembolic events (8.6% vs 6.0%; P = 0.037) were higher in the NCRT group. After propensity score matching, AL rates were 8.8% versus 11.3% (P = 0.228), with more chylothorax (2.5% vs 0.7%; P = 0.030) and trend toward more cardiovascular and thromboembolic events in the NCRT group (P = 0.069). Predictors of AL were high American Society of Anesthesiologists scores, supracarinal tumoral location, and cervical anastomosis, but not NCRT. Conclusions:Neoadjuvant chemoradiotherapy does not have an impact on the AL rate after EC resection (NCT 01927016).


Diseases of The Colon & Rectum | 2012

Right colon to rectal anastomosis (Deloyers procedure) as a salvage technique for low colorectal or coloanal anastomosis: postoperative and long-term outcomes.

Gilles Manceau; Mehdi Karoui; Sylvie Breton; Anne-Sophie Blanchet; Géraldine Rousseau; Eric Savier; Jean-Michel Siksik; Jean-Christophe Vaillant; Laurent Hannoun

BACKGROUND: After extended left colectomy, it may be difficult to take down a well-vascularized colon into the pelvis and perform a tension-free colorectal or coloanal anastomosis. The Deloyers procedure comprising complete mobilization and rotation of the right colon while maintaining the ileocolic artery may be used in this circumstance. OBJECTIVE: The aim of this study is to report postoperative and long-term outcomes after the Deloyers procedure as a salvage technique for colorectal anastomosis or coloanal anastomosis. DESIGN: From a prospective database, we retrospectively reviewed all patients who underwent a Deloyers procedure. SETTING: This study was conducted at the Colorectal Unit in a tertiary referral teaching hospital. PATIENTS: Between 1998 and 2011, 48 consecutive patients underwent a Deloyers procedure. Indications were as following: Hartmann reversal (n = 17), previous colorectal anastomosis-related complications (n = 11), diverticular disease (n = 6), left colon cancer (n = 6), ischemic colitis (n = 3), iterative colectomy for cancer (n = 3), rectal cancer local recurrence (n = 1), and synchronous colon cancer (n = 1). RESULTS: There were 38 men and 10 women (median age at surgery, 67 years). Colorectal anastomosis and coloanal anastomosis were performed in 38 and 10 patients. Thirty-one patients had defunctioning stoma. Mortality and early morbidity rate was 2% and 23%. Three patients (6%) had severe complications (Dindo ≥3). There was no anastomotic leakage. Reoperation was required in 2 patients for intra-abdominal hemorrhage. The median hospital stay was 12 days. The median follow-up was 26 months. All patients had their ileostomy closed. Twenty-three percent of patients developed late complications. The median number of bowel movements per day was 3 (range, 1–7), but 67% of patients had fewer than 3. One patient required an ileostomy refashioning because of poor functional results, and 23% of patients routinely take loperamide-based medication. LIMITATION: The retrospective nature of the study was a limitation. CONCLUSIONS: The Deloyers procedure is safe, associated with low morbidity and good long-term functional results. It represents a safe alternative to total colectomy and ileorectal anastomosis.


Clinical Cancer Research | 2015

Sonic Hedgehog and Gli1 Expression Predict Outcome in Resected Pancreatic Adenocarcinoma

Raphaël Maréchal; Jean-Baptiste Bachet; Annabelle Calomme; Pieter Demetter; Jean Robert Delpero; Magali Svrcek; Jérôme Cros; Armelle Bardier-Dupas; Francesco Puleo; Genevieve Monges; Pascal Hammel; Christophe Louvet; François Paye; Philippe P. Bachelier; Yves Patrice Le Treut; Jean-Christophe Vaillant; Alain Sauvanet; Thierry André; Isabelle Salmon; Jacques Devière; Jean-François Emile; Jean-Luc Van Laethem

Purpose: Aberrant activation of the hedgehog (Hh) pathway is implicated in pancreatic ductal adenocarcinoma (PDAC) tumorigenesis. We investigated the prognostic and predictive value of four Hh signaling proteins and of the tumor stromal density. Experimental Design: Using tissue microarray and immunohistochemistry, the expression of Shh, Gli1, SMO, and PTCH1 was assessed in 567 patients from three independent cohorts who underwent surgical resection for PDAC. In 82 patients, the tumor stromal index (SI) was calculated, and its association with overall survival (OS) and disease-free survival (DFS) was investigated. Results: Shh and Gli1 protein abundance were independent prognostic factors in resected PDACs; low expressors for those proteins experiencing a better OS and DFS. The combination of Shh and Gli1 levels was the most significant predictor for OS and defined 3 clinically relevant subgroups of patients with different prognosis (Gli1 and Shh low; HR set at 1 vs. 3.08 for Shh or Gli1 high vs. 5.69 for Shh and Gli1 high; P < 0.001). The two validating cohorts recapitulated the findings of the training cohort. After further stratification by lymph node status, the prognostic significance of combined Shh and Gli1 was maintained. The tumor SI was correlated with Shh levels and was significantly associated with OS (P = 0.023). Conclusions: Shh and Gli1 are prognostic biomarkers for patients with resected PDAC. Clin Cancer Res; 21(5); 1215–24. ©2014 AACR.


Clinical Cancer Research | 2017

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

Daniel Pietrasz; Nicolas Pécuchet; Fanny Garlan; Audrey Didelot; Olivier Dubreuil; Solène Doat; Francoise Imbert-Bismut; Mehdi Karoui; Jean-Christophe Vaillant; Valérie Taly; Pierre Laurent-Puig; Jean-Baptiste Bachet

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.

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