Papel da interleuquina-6 en gliomaxénese

Na presente tese doutoral analízase a implicación da interleuquin-6 (IL6) en gliomaxénese. O glioblastoma é un dos tumores máis agresivo e frecuente do sistema nervioso central, e os pacientes mostran niveis altos de IL6 circulante. Baixo un modelo de glioma murino, no que se recapitula a hiperactivación das vías de sinalización EGFR e FGFR coa expresión de H-RasV12, e o desaxuste do ciclo celular coa inactivación de Rb, demóstrase que esta citoquina ten un papel importante no microambiente, potenciando a progresión tumoral. Así mesmo, exerce un efecto célula-autónomo sobre as células cancerosas, cooperando na estimulación da resposta ao dano no ADN, mediante a activación de p53 e CHK1, e moderarando, vía STAT3, a reprogramación celular inducida por H-RasV12 e mediada por WIP1 a través de NF-κB

PARP1 Deficiency Reduces Tumour Growth by Decreasing E2F1 Hyperactivation: A Novel Mechanism in the Treatment of Cancer

In recent years, poly (ADP-ribose) polymerase (PARP) inhibitors have been evaluated for treating homologous recombination-deficient tumours, taking advantage of synthetic lethality. However, increasing evidence indicates that PARP1 exert several cellular functions unrelated with their role on DNA repair, including function as a co-activator of transcription through protein-protein interaction with E2F1. Since the RB/E2F1 pathway is among the most frequently mutated in many tumour types, we investigated whether the absence of PARP activity could counteract the consequences of E2F1 hyperactivation. Our results demonstrate that genetic ablation of Parp1 extends the survival of Rb-null embryos, while genetic inactivation of Parp1 results in reduced development of pRb-dependent tumours. Our results demonstrate that PARP1 plays a key role as a transcriptional co-activator of the transcription factor E2F1, an important component of the cell cycle regulation. Considering that most oncogenic processes are associated with cell cycle deregulation, the disruption of this PARP1-E2F1 interaction could provide a new therapeutic target of great interest and a wide spectrum of indicationsThis work received financial support from the Ministerio de Ciencia e Innovación (SAF2008-00543 and SAF2009-08629; J.A.C.) and ISCIII, Ministerio de Economía y Competitividad (PI15/01129), the Consellería de Cultura, Educación e Ordenación Universitaria (GPC2014/030, INCITE08PXIB208091PR and PXIB208091PR; J.A.C.), PRE/2011/131 (I.G.C.), the Centro Singular de Investigación de Galicia accreditation 2016–2019, ED431G/05), and the European Regional Development Fund (ERDF)S

RB mutation and RAS overexpression induce resistance to NK cell-mediated cytotoxicity in glioma cells

Several theories aim to explain the malignant transformation of cells, including the mutation of tumor suppressors and proto-oncogenes. Deletion of Rb (a tumor suppressor), overexpression of mutated Ras (a proto-oncogene), or both, are sufficient for in vitro gliomagenesis, and these genetic traits are associated with their proliferative capacity. An emerging hallmark of cancer is the ability of tumor cells to evade the immune system. Whether specific mutations are related with this, remains to be analyzed. To address this issue, three transformed glioma cell lines were obtained (Rb(-/-), Ras(V12), and Rb(-/-)/Ras(V12)) by in vitro retroviral transformation of astrocytes, as previously reported. In addition, Ras(V12) and Rb(-/-)/Ras(V12) transformed cells were injected into SCID mice and after tumor growth two stable glioma cell lines were derived. All these cells were characterized in terms of Rb and Ras gene expression, morphology, proliferative capacity, expression of MHC I, Rae1delta, and Rae1alphabetagammadeltaepsilon, mult1, H60a, H60b, H60c, as ligands for NK cell receptors, and their susceptibility to NK cell-mediated cytotoxicity. Our results show that transformation of astrocytes (Rb loss, Ras overexpression, or both) induced phenotypical and functional changes associated with resistance to NK cell-mediated cytotoxicity. Moreover, the transfer of cell lines of transformed astrocytes into SCID mice increased resistance to NK cell-mediated cytotoxicity, thus suggesting that specific changes in a tumor suppressor (Rb) and a proto-oncogene (Ras) are enough to confer resistance to NK cell-mediated cytotoxicity in glioma cells and therefore provide some insight into the ability of tumor cells to evade immune responses.Xunta de GaliciaComisión EuropeaInstituto de Salud Carlos IIIConsejo Nacional de Ciencia y Tecnologia (CONACyT)Consejo Nacional de Ciencia y Tecnologia (CONACyT)FOSSISXunta de Galicia/PXIB208091PRISCIII/CB158340ISCIII/CB180851FOSSIS/18236

Inhibiting HER3 Hyperphosphorylation in HER2‐Overexpressing Breast Cancer through Multimodal Therapy with Branched Gold Nanoshells

Treatment failure in breast cancers overexpressing human epidermal growth factor receptor 2 (HER2) is associated mainly to the upregulation of human epidermal growth factor receptor 3 (HER3) oncoprotein linked to chemoresitence. Therefore, to increase patient survival, here a multimodal theranostic nanoplatform targeting both HER2 and HER3 is developed. This consists of doxorubicin-loaded branched gold nanoshells functionalized with the near-infrared (NIR) fluorescent dye indocyanine green, a small interfering RNA (siRNA) against HER3, and the HER2-specific antibody Transtuzumab, able to provide a combined therapeutic outcome (chemo- and photothermal activities, RNA silencing, and immune response). In vitro assays in HER2+/HER3+ SKBR-3 breast cancer cells have shown an effective silencing of HER3 by the released siRNA and an inhibition of HER2 oncoproteins provided by Trastuzumab, along with a decrease of the serine/threonine protein kinase Akt (p-AKT) typically associated with cell survival and proliferation, which helps to overcome doxorubicin chemoresistance. Conversely, adding the NIR light therapy, an increment in p-AKT concentration is observed, although HER2/HER3 inhibitions are maintained for 72 h. Finally, in vivo studies in a tumor-bearing mice model display a significant progressively decrease of the tumor volume after nanoparticle administration and subsequent NIR light irradiation, confirming the potential efficacy of the hybrid nanocarrierE.V.-A. and I.G.-C. contributed equally to this work. This work was sup ported by the Agencia Estatal de Investigación (AEI) through Project No. PID2019-109517RB-I00) and from the Xunta de Galicia, Project No. ED431C2022/18. European Regional Development Funds are also ac knowledged. A.A.-M. and P.T. also thank the International Scientific Part nership Program ISSP at King Saud University for additional funding of this research through Grant No. ISPP-144. This work also received fi nancial support from the ISCIII, Ministerio de Economía y Competitivi dad (Grant No. PI15/01129; J.A.C.), and the AEI (Grant No. PID2020- 113501RB-I00; J.A.C.). I.-G.C. thanks for financial support through Grant No. PRE/2011/131, and the Centro Singular de Investigación de Galicia accreditation Grant No. 2016–2019 ED431G/05)S

Development of a nanocapsule-loaded hydrogel for drug delivery for intraperitoneal administration

Intraperitoneal (IP) drug delivery of chemotherapeutic agents, administered through hyperthermal intraperitoneal chemotherapy (HIPEC) and pressurized intraperitoneal aerosolized chemotherapy (PIPAC), is effective for the treatment of peritoneal malignancies. However, these therapeutic interventions are cumbersome in terms of surgical practice and are often associated with the formation of peritoneal adhesions, due to the catheters inserted into the peritoneal cavity during these procedures. Hence, there is a need for the development of drug delivery systems that can be administered into the peritoneal cavity. In this study, we have developed a nanocapsule (NCs)-loaded hydrogel for drug delivery in the peritoneal cavity. The hydrogel has been developed using poly(ethylene glycol) (PEG) and thiol-maleimide chemistry. NCs-loaded hydrogels were characterized by rheology and their resistance to dilution and drug release were determined in vitro. Using IVIS® to measure individual organ and recovered gel fluorescence intensity, an in vivo imaging study was performed and demonstrated that NCs incorporated in the PEG gel were retained in the IP cavity for 24 h after IP administration. NCs-loaded PEG gels could find potential applications as biodegradable, drug delivery systems that could be implanted in the IP cavity, for example at a the tumour resection site to prevent recurrence of microscopic tumours

Development of a biosensor based on a new marine luciferase fused to an affibody to assess Her2 expression in living cells

The development of new diagnostic tools in tumor pathology allows the optimization of individualized therapies in cancer patients. The functional optical image provides a unique opportunity to identify the pathophysiological characteristics of each tumor in a non-invasive way. Although fluorescent recombinant affibodies and nanobodies, capable of detecting certain membrane proteins present in tumor cells, has been described, the use of bioluminescent molecules is gaining a great impact in this field due to its high sensitivity. In this work, we characterize a new luciferase from the Metridia lucens copepod (MlLuc) and develop a novel bioluminescent recombinant affibody (MlLuc-aff) capable of recognizing the HER2 receptors that are overexpressed in breast cancer tumors. For this purpose, the thermostability and pH sensitivity of MlLuc1.1 were determined, showing no significant changes in the activity among temperatures between 4 and 70 °C, and with a maximum of brightness at pH 8.0. Furthermore, MlLuc-aff was able to accurately detect HER2 receptors expressed in the SK-BR-3 cells. Future applications of this new tracer can contribute to the early diagnosis of breast cancer patients and the assessment of the efficacy of the treatmentS