dianas 7(1) > Madrigal-Martínez etal

dianas | Vol 7 Num 1 | marzo 2018 | e201803a14

Prostaglandina E-2 intracelular activa los fenotipos tumorales en cáncer de próstata a través de la ciclooxigenasa-2.

Antonio Madrigal Martínez^a, Ana Belen Fernández Martínez, Francisco Javier de Lucio Cazaña

a. antoniomadrigalmartinez@gmail.com

III Congreso de Señalización Celular, SECUAH 2018.
20-22 de marzo, 2018. Universidad de Alcalá. Alcalá de Henares, Madrid. España.
Sesión A1 – Cáncer

Resumen

Ciclooxigenasa-2 (COX-2) es uno de los mediadores de la inflamación que juega un papel importante en la progresión del cáncer de próstata (CP), produce diferentes prostanoides, como la prostaglandina E2. Además, el factor inducible por hipoxia 1α (HIF-1α) juega un papel muy importante en CP, al inducir numerosos genes que contribuyen a la progresión del CP. Estudios previos de nuestro grupo de investigación, han demostrado que PGE2 intracelular (iPGE2) es capaz de activar diferentes fenotipos tumorales en células de CP y que existe una retroalimentación positiva COX-2-PGE2 que amplifica la señal inflamatoria iniciada por COX-2, ya que iPGE2 aumenta la expresión de COX-2 en células de CP. Nuestro objetivo es estudiar si iPGE2 activa los fenotipos de manera dependiente de COX-2 en una línea celular representativa de un estadio andrógeno-independiente de cáncer de próstata (PC3). Nuestros resultados muestran que iPGE2 disminuye la adhesión celular y aumenta la proliferación, migración e invasión celular, y aumenta la expresión de HIF-1α de forma dependiente de COX-2. Estos resultados sugieren que el aumento de expresión de COX-2 es fundamental para que iPGE2 active los diferentes fenotipos tumorales, contribuyendo a la progresión de CP.

dianas 7(1) > Segovia etal

dianas | Vol 7 Num 1 | marzo 2018 | e201803a23

Inhibition of a G9a-Ezh2 network triggers an immune-mediated bladder cancer regression.

Cristina Segovia, Edurne San José-Enériz, Monica Martínez-Fernández, Ester Munera-Maravilla, Leire Garate, Estíbaliz Miranda, Iris Lodewijk, Carolina Rubio, Carmen Segrelles, Obdulia Rabal, Noelia Casares, Alejandra Bernardini, José A Casado, Marta Dueñas, Felipe Villacampa, Juan José Lasarte, Felix Guerrero, Guillermo de Velasco, Julen Oyarzabal, Daniel Castellano, Xabier Aguirre, Felipe Prósper, Jesús M. Paramio

CIEMAT.

a. crismaitia@gmail.com

III Congreso de Señalización Celular, SECUAH 2018.
20-22 de marzo, 2018. Universidad de Alcalá. Alcalá de Henares, Madrid. España.
Sesión A2 – Cáncer

Abstract

Bladder cancer (BC) represents the 7th most common cancer in men and the 17th in women. At diagnoses, approximately 75% of patients present with a non-muscle invasive disease (NMIBC) and the remaining 25% of the patients showed muscle-invasive cancer (MIBC). This pathology classification determines the treatment. NMIBC are treated by transurethral resection, which can be followed by intravesical instillation with BCG or mytomycin. However, a large proportion of NMIBC show a high rate of recurrence and, in some cases, these recurrences display increased aggressiveness progressing to MIBC. The current therapeutic options of MIBC include radical cystectomy, and cisplatin-based chemotherapy with poor clinical results. In a high proportion of the cases, the disease progress showing metastatic spreading, accounting for an extremely low survival. Moreover, an important fraction of the MIBC patients presents severe comorbidities due to other pathological conditions being considered ineligible for chemotherapy with few or no therapeutic alternatives. Recently, immune checkpoint inhibitors, based on PD-1 or PDL1 blockade, have demonstrated promising results in advanced BC patients. However, the number of patients that may benefit from these therapies is still limited, as a relevant fraction does not show objective responses accounting for only partial overall survival increase. Consequently, there is a need of new avenues in advanced BC management. The molecular landscape of BC has identified multiple alterations in genes governing chromatin organization and histone modifications. The epigenomic profiles correlate with the clinical outcome indicating possible therapeutic options for patients. Regarding the chromatin-remodeler genes, the involvement of EZH2 has gained relevance in the last years, due to its implication in multiple malignancies, especially in BC. EZH2 is a histone methyltransferase that regulates gene silencing through H3K27me3 marks. G9a is another histone-methyltransferase generating H3K9me2. In addition G9a can also monomethylate H3K27 thus priming for EZH2 activity. Moreover G9a and EZH2 interact in vivo and in vitro to modulate specific gene silencing through specific genomic recruitment to a subset of target genes. However the possible roles of G9A in BC have not been elucidated. Here we report that increased expression of G9a is characteristic of BC cases in association with poor clinical outcome of bladder cancer patient. This opens the possibility that G9a inhibitors can be of benefit in the management of BC. We show that a recently described G9a/DNMT dual inhibitor (CM272) is active in BC cells in vitro and in vivo. Moreover, we also demonstrate a synergistic effect of this inhibitor with cisplatin, the current chemotherapeutic for advanced bladder cancer, in vitro and in vivo. Remarkably, in a transgenic mouse model of metastatic bladder cancer, based on the simultaneous deletion of various tumor suppressor genes in urothelial cells, the combined treatment resulted in almost complete tumor and metastasis eradication mainly through activation of immune system. These findings, support new and promising opportunities for the therapy of bladder cancer.

dianas 7(1) > Peña-Asensio etal

dianas | Vol 7 Num 1 | marzo 2018 | e201803a13

Bloqueo del miR-23a como estrategia restauradora de la respuesta celular T CD8+ específica contra antígenos asociados a hepatocarcinoma.

Julia Peña Asensio, Elia Moreno-Cubero, Juan Ramón Larrubia Marfil

Hospital Universitario de Guadalajara.

a. julia.pena@edu.uah.es

III Congreso de Señalización Celular, SECUAH 2018.
20-22 de marzo, 2018. Universidad de Alcalá. Alcalá de Henares, Madrid. España.
Sesión A1 – Cáncer

Resumen

La presencia de células T CD8 específicas con actividad efectora adecuada es esencial para el reconocimiento y eliminación de células tumorales. Sin embargo, el tumor genera un microambiente local de citoquinas supresoras, encaminado a neutralizar la actividad anti-tumoral de la respuesta inmune adaptativa. El factor de crecimiento transformante β1 (TGF-β1) secretado por las células tumorales provoca cambios epigenéticos que inducen la inmunosupresión de las células T CD8 específicas contra antígenos asociados a hepatocarcinoma. TGF-β1 produce un aumento del miR-23a que, a su vez, bloquea la expresión del factor de transcripción BLIMP-1, lo que se traduce en una incorrecta diferenciación hacia célula efectora, caracterizada por disminución de granzima B e interferón (IFN)-γ, llevando a las células a un estado de agotamiento (fenotipo CD127-, PD-1+). El bloqueo in vitro de la acción de este miR-23a con el anti-miR apropiado permitirá la restauración de la actividad efectora tras el encuentro antigénico. Esta metodología podrá ser utilizada como estrategia para la transferencia de T CD8 específicos contra antígenos asociados a hepatocarcinoma (AAH-específicos) con capacidad efectora restaurada, lo que indudablemente podría impactar en la supervivencia de pacientes con hepatocarcinoma.

dianas 7(1) > Arranz-Nicolás etal

dianas | Vol 7 Num 1 | marzo 2018 | e201803a12

DGKα inactivation is an integral component of the costimulatory pathway that amplifies TCR signals.

Javier Arranz-Nicolás, Antonia Ávila-Flores, Isabel Mérida

Centro Nacional de Biotecnología (CNB-CSIC).

a. jarranz@cnb.csic.es

III Congreso de Señalización Celular, SECUAH 2018.
20-22 de marzo, 2018. Universidad de Alcalá. Alcalá de Henares, Madrid. España.
Sesión A1 – Cáncer

Abstract

The arsenal of cancer therapies has evolved to target T lymphocytes and restore their capacity to destroy tumor cells. T cells rely on diacylglycerol (DAG) to carry out their functions. DAG availability and signaling are regulated by the enzymes diacylglycerol kinase (DGK) and , whose excess function drives T cells into hyporesponsive states. Targeting DGK is a promising strategy for coping with cancer; its blockade could reinstate T cell attack on tumors while limiting tumor growth, due to positive DGK functions in several oncogenic pathways. Here we made a side-by-side comparison of the effects of commercial pharmacological DGK inhibitors on T cell responses with those promoted by DGK and DGK genetic deletion or silencing. We show the specificity for DGK of DGK inhibitors I and II and the structurally similar compound ritanserin. Inhibitor treatment promoted Ras/ERK (extracellular signal-regulated kinase) signaling and AP-1 (Activator protein-1) transcription, facilitated DGK membrane localization, reduced the requirement for costimulation, and cooperated with enhanced activation following DGK silencing/deletion. DGKiII and ritanserin had similar effects on TCR proximal signaling, but ritanserin counteracted long-term T cell activation, an effect that was potentiated in DGK-/- cells. In contrast with enhanced activation triggered by pharmacological inhibition, DGK silencing/genetic deletion led to impaired Lck (lymphocyte-specific protein tyrosine kinase) activation and limited costimulation responses. Our results demonstrate that pharmacological inhibition of DGK downstream of the TCR provides a gain-of-function effect that amplifies the DAG-dependent signaling cascade, an ability that could be exploited therapeutically to reinvigorate T cells to attack tumors.