Minute virus of mice shows oncolytic activity against pancreatic cancer cells exhibiting a mesenchymal phenotype.

Pancreatic cancer will soon become the second cause of death by cancer in Western countries. The main barrier to increase the survival of patients with this disease requires the development of novel and efficient therapeutic strategies that better consider tumor biology. In this context, oncolytic viruses emerge as promising therapeutics. Among them, the fibrotropic minute virus of mice prototype (MVMp) preferentially infects migrating and undifferentiated cells that highly resemble poorly differentiated, basal-like pancreatic tumors showing the worst clinical outcome. We report here that MVMp specifically infects, replicates in, and kills pancreatic cancer cells from murine and human origin with a mesenchymal, basal-like profile, while sparing cancer cells with an epithelial phenotype. Remarkably, MVMp infection, at a dose that does not provoke tumor growth inhibition in athymic mice, shows significant antitumoral effect in immune-competent models; extended mouse survival; and promoted the massive infiltration of tumors by innate, myeloid, and cytotoxic T cells that exhibit a less terminally exhausted phenotype. Collectively, we demonstrate herein for the first time that MVMp is specific and oncolytic for pancreatic tumors with mesenchymal, basal-like profile, paving the way for precision-medicine opportunities for the management of the most aggressive and lethal form of this disease.

Curative surgical treatment of common bile duct stones: Retrospective cohort study.

BACKGROUND: In the event of symptomatic common bile duct (CBD) stones with dilated CBD, one possible curative treatment option is stone extraction through choledocotomy associated with cholecystectomy. Endoscopic treatment is only reserved for residual stones at 6 weeks. The aim of this study was to evaluate the results from laparoscopic curative surgical treatment of CBD stones with dilated CBD. METHODS: This is a retrospective single-centered cohort study. All consecutive patients admitted for laparoscopic cholecystectomy with evidence of CBD stones with dilated CBD from January 2010 to December 2020 at our center were included. Success was defined by CBD clearance at 6 weeks. Need for additional procedures, such as endoscopic sphincterotomy, immediate, and end-of-procedure morbi-mortality as well as factors associated with procedure failure, were also studied. RESULTS: A total of 246 patients who received curative treatment were included in the study. The success rate for the curative treatment was 93.1% (229 patients). Immediate postoperative morbidity was 24.4% with a 5.3% reintervention rate. Immediate and 6-week postoperative mortality rates were zero and 0.4%, respectively. The mean length of stay was 11.3 days. Factors associated with procedure failure appeared to be the occurrence of an early postoperative complication and the need for readmission during the period between surgery and drain removal. CONCLUSION: This study indicates that laparoscopic curative surgical treatment for symptomatic CBD stones may be performed with acceptable results without routine need for additional procedures.

Cytidine Deaminase Resolves Replicative Stress and Protects Pancreatic Cancer from DNA-Targeting Drugs.

Cytidine deaminase (CDA) functions in the pyrimidine salvage pathway for DNA and RNA syntheses and has been shown to protect cancer cells from deoxycytidine-based chemotherapies. In this study, we observed that CDA was overexpressed in pancreatic adenocarcinoma from patients at baseline and was essential for experimental tumor growth. Mechanistic investigations revealed that CDA localized to replication forks where it increased replication speed, improved replication fork restart efficiency, reduced endogenous replication stress, minimized DNA breaks, and regulated genetic stability during DNA replication. In cellular pancreatic cancer models, high CDA expression correlated with resistance to DNA-damaging agents. Silencing CDA in patient-derived primary cultures in vitro and in orthotopic xenografts in vivo increased replication stress and sensitized pancreatic adenocarcinoma cells to oxaliplatin. This study sheds light on the role of CDA in pancreatic adenocarcinoma, offering insights into how this tumor type modulates replication stress. These findings suggest that CDA expression could potentially predict therapeutic efficacy and that targeting CDA induces intolerable levels of replication stress in cancer cells, particularly when combined with DNA-targeted therapies. SIGNIFICANCE: Cytidine deaminase reduces replication stress and regulates DNA replication to confer resistance to DNA-damaging drugs in pancreatic cancer, unveiling a molecular vulnerability that could enhance treatment response.

Preclinical development of non-viral gene therapy for patients with advanced pancreatic cancer.

Pancreatic cancer remains one of the greatest challenges in oncology for which therapeutic intervention is urgently needed. We previously demonstrated that the intra-tumoral gene transfer of somatostatin receptor 2, to combat tumor aggressiveness, or of deoxycytidine kinase and uridylate monophosphate kinase, to sensitize to gemcitabine chemotherapy, has anti-tumoral potential in experimental models of cancer. Here, we describe the development of the CYL-02 non-viral gene therapy product that comprises a DNA-plasmid encoding for the three aforementioned genes, which expression is targeted to tumor cells, and complexed with polyethyleneimine non-viral vector. We performed pre-clinical toxicology, bio-distribution, and therapeutic activity studies of CYL-02 in two rodent models of pancreatic cancer. We found that CYL-02 is safe, does not increase gemcitabine toxicity, is rapidly cleared from blood following intravenous administration, and sequestered in tumors following intra-tumoral injection. CYL-02 drives the expression of therapeutic genes in cancer cells and strongly sensitizes tumor cells to gemcitabine, both in vitro and in vivo, with significant inhibition of tumor cells dissemination. This study was instrumental for the later use of CYL-02 in patients with advanced pancreatic cancer, demonstrating that rigorous and thorough preclinical investigations are informative for the clinical transfer of gene therapies against this disease.

Pancreatic Cancer in Chronic Pancreatitis: Pathogenesis and Diagnostic Approach.

Chronic pancreatitis is one of the main risk factors for pancreatic cancer, but it is a rare event. Inflammation and oncogenes work hand in hand as key promoters of this disease. Tobacco is another co-factor. During alcoholic chronic pancreatitis, the cumulative risk of cancer is estimated at 4% after 15 to 20 years. This cumulative risk is higher in hereditary pancreatitis: 19 and 12% in the case of PRSS1 and SPINK1 mutations, respectively, at an age of 60 years. The diagnosis is difficult due to: (i) clinical symptoms of cancer shared with those of chronic pancreatitis; (ii) the parenchymal and ductal remodeling of chronic pancreatitis rendering imaging analysis difficult; and (iii) differential diagnoses, such as pseudo-tumorous chronic pancreatitis and paraduodenal pancreatitis. Nevertheless, the occurrence of cancer during chronic pancreatitis must be suspected in the case of back pain, weight loss, unbalanced diabetes, and jaundice, despite alcohol withdrawal. Imaging must be systematically reviewed. Endoscopic ultrasound-guided fine-needle biopsy can contribute by targeting suspicious tissue areas with the help of molecular biology (search for KRAS, TP53, CDKN2A, DPC4 mutations). Short-term follow-up of patients is necessary at the clinical and paraclinical levels to try to diagnose cancer at a surgically curable stage. Pancreatic surgery is sometimes necessary if there is any doubt.

Pancreatic Cancer Cell and Gene Biotherapies: Past, Present, and Future.

Solid cancers remain a major health challenge in terms of research, not only due to their structure and organization but also in the molecular and genetic variations present between tumors as well as within the same tumor. When adding on the tumor microenvironment with cancer-associated cells, vasculature, and the body's immune response (or lack of), the weapons used to tackle this disease must also be diverse and intricate. Developing gene-based therapies against tumors contributes to the diverse lines of attack already established for cancers and can potentially overcome certain obstacles encountered with these strategies, the lack of tumor selectivity with chemotherapies, for example. Given the high mortality and relapse rate associated with pancreatic cancer, novel treatments, including gene therapy, are actively being investigated. Even though no gene therapy for pancreatic cancer is currently on the market, a significant amount of clinical trials are underway, especially in active and recruiting or recently completed phases.

Prevention of post-operative recurrence of Crohn's disease among patients with prior anti-TNFα failure: A retrospective multicenter study.

BACKGROUND: Anti-TNFα are recommended for preventing Crohn's disease (CD) postoperative recurrence (POR) in patients with risk factors. However, few data exploring anti-TNFα efficacy in patients with preoperative anti-TNFα failure are available so far. AIMS: The aim of the present study was to compare the efficacy of anti-TNFα with other biologics and immunosuppressants to prevent POR in this setting. METHODS: Consecutive CD patients who underwent bowel resection between January 2010 and December 2019 after failure of at least one anti-TNFα were retrospectively included among three tertiary centers if they started a postoperative medical prophylaxis within the three months after index surgery. The main outcome was to compare rates of objective recurrence (endoscopic or radiological recurrence in absence of colonoscopy) between patients treated with an anti-TNFα agent or another treatment as prevention of POR. RESULTS: Among the 119 patients included, 71 patients received an anti-TNFα (26 infliximab, 45 adalimumab) and 48 another treatment (18 ustekinumab, 7 vedolizumab, 20 azathioprine and 3 methotrexate) to prevent POR. Rates of objective recurrence at two years were 23.9% in patients treated with anti-TNFα and 44.9% in the others (p = 0.011). CONCLUSION: Anti-TNFα remained an effective option to prevent POR for patients operated upon with previous anti-TNFα failure.

Endoscopic ultrasound as a reliable tool for assessment of pancreatic adenocarcinoma treatment: Example of in situ gene therapy.

Background and study aims In pancreatic cancer, the antitumor effect can only be assessed by means of a computed tomography (CT) scan using RECIST (Response Evaluation Criteria in Solid Tumours) criteria. The aim of this study was to assess the intra-observer and interobserver agreement of endoscopic ultrasound (EUS) imaging in assessing tumor volume in primary pancreatic cancer. Patients and methods During a Phase 1 gene therapy trial, 21 patients had EUS before the first and second EUS-guided in situ gene therapy injections. All anonymized EUS files were then randomly distributed to three gastroenterologists/endosonographers and three radiologists (blind status). The largest tumor diameter was measured and the intraclass correlation coefficient (ICC) was determined. Results Intra-observer and interobserver agreements were good to excellent, regardless of operator experience (junior versus senior member of staff) (ICC: 0.65 to 0.84). A comparison of pretreatment and post-treatment measurements by the investigators highlighted a significant antitumor effect (-11 %; P  = 0.0098), similar to that obtained during the generic protocol (-10 %; P  = 0.0045). Conclusions Interobserver agreement regarding primary pancreatic adenocarcinoma measurements appears good to excellent, thus paving the way for the future inclusion of EUS assessments, particularly in trials assessing local therapies for pancreatic tumors.

Incidence and Risk Factors of Cancer in the Anal Transitional Zone and Ileal Pouch following Surgery for Ulcerative Colitis and Familial Adenomatous Polyposis.

Proctocolectomy with ileal pouch-anal anastomosis is the intervention of choice for ulcerative colitis and familial adenomatous polyposis requiring surgery. One of the long-term complications is pouch cancer, having a poor prognosis. The risk of high-grade dysplasia and cancer in the anal transitional zone and ileal pouch after 20 years is estimated to be 2 to 4.5% and 3 to 10% in ulcerative colitis and familial polyposis, respectively. The risk factors for ulcerative colitis are the presence of pre-operative dysplasia or cancer, disease duration > 10 years and severe villous atrophy. For familial polyposis, the risk factors are the number of pre-operative polyps > 1000, surgery with stapled anastomosis and the duration of follow-up. In the case of ulcerative colitis, a pouchoscopy should be performed annually if one of the following is present: dysplasia and cancer at surgery, primary sclerosing cholangitis, villous atrophy and active pouchitis (every 5 years without any of these factors). In the case of familial polyposis, endoscopy is recommended every year including chromoendoscopy. Even if anal transitional zone and ileal pouch cancers seldom occur following proctectomy for ulcerative colitis and familial adenomatous polyposis, the high mortality rate associated with this complication warrants endoscopic monitoring.

The antitumoral activity of TLR7 ligands is corrupted by the microenvironment of pancreatic tumors.

Toll-like receptors (TLRs) are key players in the innate immune system. Recent studies have suggested that they may affect the growth of pancreatic cancer, a disease with no cure. Among them, TLR7 shows promise for therapy but may also promotes tumor growth. Thus, we aimed to clarify the therapeutic potential of TLR7 ligands in experimental pancreatic cancer models, to open the door for clinical applications. In vitro, we found that TLR7 ligands strongly inhibit the proliferation of both human and murine pancreatic cancer cells, compared with TLR2 agonists. Hence, TLR7 treatment alters cancer cells' cell cycle and induces cell death by apoptosis. In vivo, TLR7 agonist therapy significantly delays the growth of murine pancreatic tumors engrafted in immunodeficient mice. Remarkably, TLR7 ligands administration instead increases tumor growth and accelerates animal death when tumors are engrafted in immunocompetent models. Further investigations revealed that TLR7 agonists modulate the intratumoral content and phenotype of macrophages and that depleting such tumor-associated macrophages strongly hampers TLR7 agonist-induced tumor growth. Collectively, our findings shine a light on the duality of action of TLR7 agonists in experimental cancer models and call into question their use for pancreatic cancer therapy.

Functionally deficient TRPV6 variants contribute to hereditary and familial chronic pancreatitis.

The recent discovery of TRPV6 as a pancreatitis susceptibility gene served to identify a novel mechanism of chronic pancreatitis (CP) due to Ca2+ dysregulation. Herein, we analyzed TRPV6 in 81 probands with hereditary CP (HCP), 204 probands with familial CP (FCP), and 462 patients with idiopathic CP (ICP) by targeted next-generation sequencing. We identified 25 rare nonsynonymous TRPV6 variants, 18 of which had not been previously reported. All 18 variants were characterized by a Ca2+ imaging assay, with 8 being identified as functionally deficient. Evaluation of functionally deficient variants in the three CP cohorts revealed two novel findings: (i) functionally deficient TRPV6 variants appear to occur more frequently in HCP/FCP patients than in ICP patients (3.2% vs. 1.5%) and (ii) functionally deficient TRPV6 variants found in HCP and FCP probands appear to be more frequently coinherited with known risk variants in SPINK1, CTRC, and/or CFTR than those found in ICP patients (66.7% vs 28.6%). Additionally, genetic analysis of available HCP and FCP family members revealed complex patterns of inheritance in some families. Our findings confirm that functionally deficient TRPV6 variants represent an important contributor to CP. Importantly, functionally deficient TRPV6 variants account for a significant proportion of cases of HCP/FCP.

Adipose-Derived Stem Cells in the Treatment of Perianal Fistulas in Crohn's Disease: Rationale, Clinical Results and Perspectives.

Between 20 to 25% of Crohn's disease (CD) patients suffer from perianal fistulas, a marker of disease severity. Seton drainage combined with anti-TNFα can result in closure of the fistula in 70 to 75% of patients. For the remaining 25% of patients there is room for in situ injection of autologous or allogenic mesenchymal stem cells such as adipose-derived stem/stromal cells (ADSCs). ADSCs exert their effects on tissues and effector cells through paracrine phenomena, including the secretome and extracellular vesicles. They display anti-inflammatory, anti-apoptotic, pro-angiogenic, proliferative, and immunomodulatory properties, and a homing within the damaged tissue. They also have immuno-evasive properties allowing a clinical allogeneic approach. Numerous clinical trials have been conducted that demonstrate a complete cure rate of anoperineal fistulas in CD ranging from 46 to 90% of cases after in situ injection of autologous or allogenic ADSCs. A pivotal phase III-controlled trial using allogenic ADSCs (Alofisel®) demonstrated that prolonged clinical and radiological remission can be obtained in nearly 60% of cases with a good safety profile. Future studies should be conducted for a better knowledge of the local effect of ADSCs as well as for a standardization in terms of the number of injections and associated procedures.

Perineal Wound Closure Following Abdominoperineal Resection and Pelvic Exenteration for Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND: Abdominoperineal resection (APR) and pelvic exenteration (PE) for the treatment of cancer require extensive pelvic resection with a high rate of postoperative complications. The objective of this work was to systematically review and meta-analyze the effects of vertical rectus abdominis myocutaneous flap (VRAMf) and mesh closure on perineal morbidity following APR and PE (mainly for anal and rectal cancers). METHODS: We searched PubMed, Cochrane, and EMBASE for eligible studies as of the year 2000. After data extraction, a meta-analysis was performed to compare perineal wound morbidity. The studies were distributed as follows: Group A comparing primary closure (PC) and VRAMf, Group B comparing PC and mesh closure, and Group C comparing PC and VRAMf in PE. RESULTS: Our systematic review yielded 18 eligible studies involving 2180 patients (1206 primary closures, 647 flap closures, 327 mesh closures). The meta-analysis of Groups A and B showed PC to be associated with an increase in the rate of total (Group A: OR 0.55, 95% CI 0.43-0.71; p < 0.01/Group B: OR 0.54, CI 0.17-1.68; p = 0.18) and major perineal wound complications (Group A: OR 0.49, 95% CI 0.35-0.68; p < 0.001/Group B: OR 0.38, 95% CI 0.12-1.17; p < 0.01). PC was associated with a decrease in total (OR 2.46, 95% CI 1.39-4.35; p < 0.01) and major (OR 1.67, 95% CI 0.90-3.08; p = 0.1) perineal complications in Group C. CONCLUSION: Our results confirm the contribution of the VRAMf in reducing major complications in APR. Similarly, biological prostheses offer an interesting alternative in pelvic reconstruction. For PE, an adapted reconstruction must be proposed with specialized expertise.

A Novel Imaging Approach for Single-Cell Real-Time Analysis of Oncolytic Virus Replication and Efficacy in Cancer Cells.

Oncolytic viruses (OVs) are novel cancer gene therapies that are moving toward the forefront of modern medicines. However, their full therapeutic potential is hindered by the lack of convenient and reliable strategies to visualize and quantify OV growth kinetics and therapeutic efficacy in live cells. In this study, we present an innovative imaging approach for single-cell real-time analysis of OV replication and efficacy in cancer cells. We selected SG33 as a prototypic new OV that derives from wild-type Myxoma virus (MYXV). Lausanne Toulouse 1 (T1) was used as control. We equipped SG33 and T1 genomes with the ANCHOR system and infected a panel of cell lines. The ANCHOR system is composed of a fusion protein (OR-GFP) that specifically binds to a short nonrepetitive DNA target sequence (ANCH) and spreads onto neighboring sequences by protein oligomerization. Its accumulation on the tagged viral DNA results in the creation of fluorescent foci. We found that (1) SG33 and T1-ANCHOR DNA can be readily detected and quantified by live imaging, (2) both OVs generate perinuclear replication foci after infection clustering into horse-shoe shape replication centers, and (3) SG33 replicates to higher levels as compared with T1. Lastly, as a translational proof of concept, we benchmarked SG33 replication and oncolytic efficacy in primary cancer cells derived from pancreatic adenocarcinoma (PDAC) both at the population and at the single-cell levels. In vivo, SG33 significantly replicates in experimental tumors to inhibit tumor growth. Collectively, we provide herein for the first time a novel strategy to quantify each step of OV infection in live cells and in real time by tracking viral DNA and provide first evidence of theranostic strategies for PDAC patients. Thus, this approach has the potential to rationalize the use of OVs for the benefit of patients with incurable diseases.

Increased Mucosal Thrombin is Associated with Crohn's Disease and Causes Inflammatory Damage through Protease-activated Receptors Activation.

BACKGROUND AND AIMS: Thrombin levels in the colon of Crohn's disease patients have recently been found to be elevated 100-fold compared with healthy controls. Our aim was to determine whether and how dysregulated thrombin activity could contribute to local tissue malfunctions associated with Crohn's disease. METHODS: Thrombin activity was studied in tissues from Crohn's disease patients and healthy controls. Intracolonic administration of thrombin to wild-type or protease-activated receptor-deficient mice was used to assess the effects and mechanisms of local thrombin upregulation. Colitis was induced in rats and mice by the intracolonic administration of trinitrobenzene sulphonic acid. RESULTS: Active forms of thrombin were increased in Crohn's disease patient tissues. Elevated thrombin expression and activity were associated with intestinal epithelial cells. Increased thrombin activity and expression were also a feature of experimental colitis in rats. Colonic exposure to doses of active thrombin comparable to what is found in inflammatory bowel disease tissues caused mucosal damage and tissue dysfunctions in mice, through a mechanism involving both protease-activated receptors -1 and -4. Intracolonic administration of the thrombin inhibitor dabigatran, as well as inhibition of protease-activated receptor-1, prevented trinitrobenzene sulphonic acid-induced colitis in rodent models. CONCLUSIONS: Our data demonstrated that increased local thrombin activity, as it occurs in the colon of patients with inflammatory bowel disease, causes mucosal damage and inflammation. Colonic thrombin and protease-activated receptor-1 appear as possible mechanisms involved in mucosal damage and loss of function and therefore represent potential therapeutic targets for treating inflammatory bowel disease.

Primary Thromboprophylaxis in Ambulatory Pancreatic Cancer Patients Receiving Chemotherapy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Patients with pancreatic cancer (PC) carry the highest risk of venous thromboembolism (VTE) amongst all cancer patients. Appropriate use of primary thromboprophylaxis might significantly and safely reduce its burden. We performed a systematic review of published studies and meeting abstracts using MEDLINE and EMBASE through July 2020 to evaluate the efficacy and safety of primary thromboprophylaxis in ambulatory PC patients receiving chemotherapy. The Mantel-Haenszel random effect model was used to estimate the pooled event-based risk ratio (RR) and the pooled absolute risk difference (RD) with a 95% confidence interval (CI). Five randomized controlled studies with 1003 PC patients were included in this meta-analysis. Compared to placebo, thromboprophylaxis significantly decreased the risk of VTE (pooled RR 0.31, 95% CI 0.19-0.51, p < 0.00001, I2 = 8%; absolute RD -0.08, 95% CI -0.12--0.05, p < 0.00001, I2 = 0%), with an estimated number needed to treat of 11.9 patients to prevent one VTE event. Similar reductions of VTE were observed in studies with parenteral (RR 0.30, 95% CI 0.17-0.53) versus oral anticoagulants (RR 0.37, 95% CI 0.14-0.99) and in studies using prophylactic doses of anticoagulants (RR 0.34, 95% CI 0.17-0.70) versus supra-prophylactic doses of anticoagulants (RR 0.27, 95% CI 0.08-0.90). The pooled RR for major bleeding was 1.08 (95% CI 0.47-2.52, p = 0.85, I2 = 0%) and the absolute RD was 0.00 (95% CI -0.02-0.03, p = 0.85, I2 = 0%). Evidence supports a net clinical benefit of thromboprophylaxis in ambulatory PC patients receiving chemotherapy. Adequately powered randomized phase III studies assessing the most effective anticoagulant and the optimal dose, schedule and duration of thromboprophylaxis to be used are warranted.

Establishment of a pancreatic adenocarcinoma molecular gradient (PAMG) that predicts the clinical outcome of pancreatic cancer.

BACKGROUND: A significant gap in pancreatic ductal adenocarcinoma (PDAC) patient's care is the lack of molecular parameters characterizing tumours and allowing a personalized treatment. METHODS: Patient-derived xenografts (PDX) were obtained from 76 consecutive PDAC and classified according to their histology into five groups. A PDAC molecular gradient (PAMG) was constructed from PDX transcriptomes recapitulating the five histological groups along a continuous gradient. The prognostic and predictive value for PMAG was evaluated in: i/ two independent series (n = 598) of resected tumours; ii/ 60 advanced tumours obtained by diagnostic EUS-guided biopsy needle flushing and iii/ on 28 biopsies from mFOLFIRINOX treated metastatic tumours. FINDINGS: A unique transcriptomic signature (PAGM) was generated with significant and independent prognostic value. PAMG significantly improves the characterization of PDAC heterogeneity compared to non-overlapping classifications as validated in 4 independent series of tumours (e.g. 308 consecutive resected PDAC, uHR=0.321 95% CI [0.207-0.5] and 60 locally-advanced or metastatic PDAC, uHR=0.308 95% CI [0.113-0.836]). The PAMG signature is also associated with progression under mFOLFIRINOX treatment (Pearson correlation to tumour response: -0.67, p-value < 0.001). INTERPRETATION: PAMG unify all PDAC pre-existing classifications inducing a shift in the actual paradigm of binary classifications towards a better characterization in a gradient. FUNDING: Project funding was provided by INCa (Grants number 2018-078 and 2018-079, BACAP BCB INCa_6294), Canceropole PACA, DGOS (labellisation SIRIC), Amidex Foundation, Fondation de France, INSERM and Ligue Contre le Cancer.