Bioselection Reveals miR-99b and miR-485 as Enhancers of Adenoviral Oncolysis in Pancreatic Cancer

Oncolytic viruses are designed for cancer treatment. Cell-virus interactions are key determinants for successful viral replication. Therefore, the extensive reprogramming of gene expression that occurs in tumor cells might create a hurdle for viral propagation. We used a replication-based approach of a microRNA (miRNA) adenoviral library encoding up to 243 human miRNAs as a bioselection strategy to identify miRNAs that facilitate adenoviral oncolytic activity in pancreatic ductal adenocarcinoma. We identify two miRNAs, miR-99b and miR-85, that function as enhancers of adenoviral oncolysis by improving the intra-and extracellular yield of mature virions. An increased adenoviral activity is the consequence of enhanced E1A and late viral protein expression, which is probably mediated by the downregulation of the transcriptional repressors ELF4, MDM2, and KLF8, which we identify as miR-99b or miR-485 target genes. Arming the oncolytic adenovirus ICOVIR15 with miR-99b or miR-485 enhances its fitness and its antitumoral activity. Our results demonstrate the potential of this strategy to improve oncolytic adenovirus potency, and they highlight miR-99b and miR-485 as sensitizers of adenoviral replication

Patient-derived pancreatic tumour organoids identify therapeutic responses to oncolytic adenoviruses.

Background: Pancreatic patient-derived organoids (PDOs) are a well-established model for studying pancreatic ductal adenocarcinoma (PDAC) carcinogenesis and are potential predictors of clinical responses to chemotherapy. Oncolytic virotherapy is envisioned as a novel treatment modality for pancreatic cancer, and candidate viruses are being tested in clinical trials. Here, we explore the feasibility of using PDOs as a screening platform for the oncolytic adenovirus (OA) response. Methods: Organoids were established from healthy pancreas and PDAC tissues and assessed for infectivity, oncoselectivity, and patient-dependent sensitivity to OA. Antitumour effects were studied in vivo in organoid xenografts. Further evaluation of oncolytic responses was conducted in organoids derived from orthotopic models or metastastic tissues.Findings: Oncolytic adenoviruses display good selectivity, with replication only in organoids derived from PDAC tumours. Furthermore, responses of PDOs to a set of OAs reveal individual differences in cytotoxicity as well as in synergism with standard chemotherapy. Adenoviral cytotoxicity in PDOs is predictive of antitumour efficacy in a subcutaneous xenograft setting. Organoids from orthotopic tumours and metastases in nude mice mirror the viral preference of PDOs, indicating that PDO sensitivity to OAs could be informative about responses in both primary tumours and metastatic foci. Interpretation: Our data imply that pancreatic PDOs can serve as predictive tools for screening for sensitivity to OA

Adenovirus oncoselectius pel tractament de càncer de pàncrees. Combinació d'estratègies de direccionament a tumor i bioselecció de microRNAs potenciadors de l'activitat adenoviral

[cat] L’adenocarcinoma ductal pancreàtic (PDAC) és una neoplàsia molt agressiva a conseqüència de la seva elevada capacitat metastàtica i la gran resistència que presenta als tractaments convencionals de quimioteràpia i radioteràpia. Només un percentatge molt reduït de pacients és elegible per a la resecció quirúrgica del tumor, l’únic tractament amb opcions de cura. La major part dels casos són diagnosticats en estadis avançats de la malaltia en els que la supervivència a 5-anys se situa al voltant del 7%. La millora del pronòstic dels pacients amb càncer de pàncrees ha estat pràcticament nul·la en els últims 30 anys, de manera que existeix una clara necessitat de desenvolupar nous mètodes per facilitar la detecció precoç del tumor i teràpies més efectives pel seu tractament. Els adenovirus oncolítics estan esdevenint una teràpia prometedora pel tractament de neoplàsies agressives com el PDAC, obtenint resultats prometedors en assajos clínics. Tanmateix, els virus administrats fins al moment no han permès aconseguir respostes antitumorals complertes i és necessari disposar d’adenovirus més potents, però també de replicació selectiva en tumor. En el primer bloc d’aquesta tesi, ens hem fixat en algunes de les desregulacions que presenten les cèl·lules tumorals per tal de dissenyar estratègies de direccionament a tumor i obtenir adenovirus oncoselectius més segurs. Concretament, l’increment de l’expressió de metal·loproteases de matriu, la reactivació en els tumors de vies relacionades amb el desenvolupament embrionari i la pèrdua de l’expressió de miRNAs específics de teixit han estat el racional per a generar modificacions genètiques que permetessin regular l’entrada dels adenovirus a la cèl·lula i l’expressió del gen E1A a nivell transcripcional i post-transcripcional. D’aquesta manera, s’ha determinat que la combinació de diversos mecanismes de control de la replicació viral permet obtenir adenovirus més segurs per una administració sistèmica tot mantenint una activitat antitumoral significativa. En el segon bloc de la tesi, ens hem centrat en conferir més potència als adenovirus oncolítics. Vam hipotetitzar que les desregulacions en els perfils d’expressió de miRNAs de les cèl·lules tumorals podrien tenir un impacte negatiu en el cicle adenoviral, limitar la formació de nova progènia viral i per tant, reduir l’eficàcia antitumoral dels adenovirus oncolítics. Amb l’objectiu de contrarestar aquestes possibles limitacions i obtenir adenovirus amb una activitat antitumoral augmentada, es va dur a terme la bioselecció d’una biblioteca de miRNAs humans en adenovirus per tal d’identificar miRNAs potenciadors de l’activitat adenoviral en PDAC. A través d’aquest sistema high-throughput, es va determinar que el miR-99b i el miR-485 milloraven l’expressió dels gens virals i la formació de virions infectius en cèl·lules de PDAC gràcies a la regulació, directa o indirecta, de factors cel·lulars amb expressió diferencial en cèl·lules neoplàsiques i cèl·lules no tumorals. Així doncs, la identificació de miRNAs que milloraven el fitness viral va permetre obtenir adenovirus oncoselectius més potents front a PDAC.[eng] Pancreatic ductal adenocarcinoma (PDAC) is a very aggressive neoplasia due to its high metastatic capacity and its resistance to chemotherapy. A small number of patients are eligible for tumor resection, the only curative treatment, and most of the cases are diagnosed at an advanced stage of the disease, in which the 5-year survival is around 7%. Therefore, there is a clear need for the development of better diagnostic methods and more effective treatments for this neoplasia. Oncolytic adenoviruses are becoming a promising therapy for the treatment of aggressive cancers, such as PDAC. Promising results have been obtained in clinical trials, although complete antitumoral responses have not been reached and more potent but also more selective viruses are required. In this thesis, we have focused in some deregulations present in cancer cells in order to design tumor targeting strategies for adenoviruses. Specifically, the overexpression of matrix metalloproteases, the reactivation of embryonic pathways and the loss of tissue specific miRNA’s expression have been the rational for the genetic modifications that allow the control of viral replication at transductional, transcriptional and post-transcriptional levels. We have determined that the combination of different strategies is useful for obtaining safer adenovirus for a systemic administration while maintaining a significant antitumoral activity. We have also focused in conferring more potency to oncolytic adenoviruses. We hypothesized that deregulations of miRNA profiles in cancer cells may have a negative impact on the adenoviral cycle, reducing the antitumoral efficiency of the virus. With the objective to counteract these limitations, we performed a bioselection of a human miRNA adenoviral library, aiming to identify miRNAs that confer potency to the adenoviruses against PDAC. We identified that miR-99b and miR-485 improved viral gene expression and the formation of infective particles in PDAC through the direct or indirect regulation of cellular factors differentially expressed in neoplastic cells and non-tumoral cells. Therefore, the identification of miRNAs that improved viral fitness gave rise to more potent oncoselective viruses against PDAC

Oligopeptide-modified poly(beta-amino ester)s-coated AdNuPARmE1A: boosting the efficacy of intravenously administered therapeutic adenoviruses

Oncolytic adenoviruses are used as agents for the treatment of cancer. However, their potential is limited due to the high seroprevalence of anti-adenovirus neutralizing antibodies (nAbs) within the population and the rapid liver sequestration when systemically administered. To overcome these challenges, we explored using nanoparticle formulation to boost the efficacy of systemic oncolytic adenovirus administration. Methods: Adenovirus were conjugated with PEGylated oligopeptide-modified poly(β-amino ester)s (OM-pBAEs). The resulting coated viral formulation was characterized in terms of surface charge, size, aggregation state and morphology and tested for anti-adenovirus nAbs evasion and activity in cancer cells. In vivo pharmacokinetics, biodistribution, tumor targeting, and immunogenicity studies were performed. The antitumor efficacy of the oncolytic adenovirus AdNuPARmE1A coated with OM-pBAEs (SAG101) in the presence of nAbs was evaluated in pancreatic ductal adenocarcinoma (PDAC) mouse models. Toxicity of the coated formulation was analyzed in vivo in immunocompetent mice. Results: OM-pBAEs conjugated to adenovirus and generated discrete nanoparticles with a neutral charge and an optimal size. The polymeric coating with the reporter AdGFPLuc (CPEG) showed enhanced transduction and evasion of antibody neutralization in vitro. Moreover, systemic intravenous administration of the formulation showed improved blood circulation and reduced liver sequestration, substantially avoiding activation of nAb production. OM-pBAEs coating of the oncolytic adenovirus AdNuPARmE1A (SAG101) improved its oncolytic activity in vitro and enhanced antitumor efficacy in PDAC mouse models. The coated formulation protected virions from neutralization by nAbs, as antitumor efficacy was preserved in their presence but was completely lost in mice that received the non-formulated AdNuPARmE1A. Finally, coated-AdNuPARmE1A showed reduced toxicity when high doses of the formulation were administered. Conclusions: The developed technology represents a promising improvement for future clinical cancer therapy using oncolytic adenoviruses

Oligopeptide-modified poly(beta-amino ester)s-coated AdNuPARmE1A:boosting the efficacy of intravenously administered therapeutic adenoviruses

\u3cp\u3eOncolytic adenoviruses are used as agents for the treatment of cancer. However, their potential is limited due to the high seroprevalence of anti-adenovirus neutralizing antibodies (nAbs) within the population and the rapid liver sequestration when systemically administered. To overcome these challenges, we explored using nanoparticle formulation to boost the efficacy of systemic oncolytic adenovirus administration. Methods: Adenovirus were conjugated with PEGylated oligopeptide-modified poly(β-amino ester)s (OM-pBAEs). The resulting coated viral formulation was characterized in terms of surface charge, size, aggregation state and morphology and tested for anti-adenovirus nAbs evasion and activity in cancer cells. In vivo pharmacokinetics, biodistribution, tumor targeting, and immunogenicity studies were performed. The antitumor efficacy of the oncolytic adenovirus AdNuPARmE1A coated with OM-pBAEs (SAG101) in the presence of nAbs was evaluated in pancreatic ductal adenocarcinoma (PDAC) mouse models. Toxicity of the coated formulation was analyzed in vivo in immunocompetent mice. Results: OM-pBAEs conjugated to adenovirus and generated discrete nanoparticles with a neutral charge and an optimal size. The polymeric coating with the reporter AdGFPLuc (CPEG) showed enhanced transduction and evasion of antibody neutralization in vitro. Moreover, systemic intravenous administration of the formulation showed improved blood circulation and reduced liver sequestration, substantially avoiding activation of nAb production. OM-pBAEs coating of the oncolytic adenovirus AdNuPARmE1A (SAG101) improved its oncolytic activity in vitro and enhanced antitumor efficacy in PDAC mouse models. The coated formulation protected virions from neutralization by nAbs, as antitumor efficacy was preserved in their presence but was completely lost in mice that received the non-formulated AdNuPARmE1A. Finally, coated-AdNuPARmE1A showed reduced toxicity when high doses of the formulation were administered. Conclusions: The developed technology represents a promising improvement for future clinical cancer therapy using oncolytic adenoviruses.\u3c/p\u3