[en] The HMGB family of proteins includes nuclear proteins with the ability to bind DNA and participate in transcriptional regulation and DNA repair processes, as well as to respond to cellular oxidative damage. The main objective of this work aims to identify new physical interactions of the HMGB1 and HMGB2 proteins with other proteins in ovarian and prostate tumours. The identification of new physical interactions of these proteins would allow a better understanding of their mechanism of action and their role in cancer-related signaling pathways. Through experimental approaches based on the double hybrid, proteomic studies have been carried out using cDNA libraries prepared from isolated ovarian and prostate tumours from patients. The functionality of the interactions found has also been validated by bioinformatic meta-analyses of other data collected in databases on their expression levels and association with clinical survival parameters. Two selected interactions have also been validated by co-immunoprecipitation and by cell localization using confocal microscopy from cancer cells in culture. Some functional characteristics of HMGB1 and HMGB2 proteins, as well as NOP53 and MIEN1, detected in this study as new proteins of physical interaction with HMGB proteins have been analyzed in greater detail. The effects produced by its silencing and the variation in expression levels in reaction to external treatments with compounds used in chemotherapy such as carboplatin, paclitaxel, olaparib and bevacizumab were analyzed. In addition, the HMGB1, HMGB2, NOP53 and MIEN1 proteins, together with the miRNAs miR-155, miR-124 and miR-146a, were detected in extracellular vesicles (EV) derived from prostate cell lines, and variations were observed after treatment with temozolomide (TMZ) or a new hybrid compound based on TMZ and valproic acid (1D). This study is the basis for the search for new biomarkers or therapeutic targets useful to overcome resistance to anti-tumour drugs currently used in these types of cancer.

[gl] A familia de proteínas HMGB está formada por proteínas nucleares con capacidade de unirse o ADN e participar na regulación transcricional e nos procesos de reparación do ADN, así como para responder aos danos oxidativos celulares. O desenvolvemento deste traballo ten como obxectivo identificar novas interaccións físicas das proteínas HMGB1 e HMGB2 con outras proteínas en tumores de ovario e próstata. A identificación de novas interaccións físicas destas proteínas permitiría unha mellor comprensión do seu mecanismo de acción e do seu papel nas vías de sinalización relacionadas co cancro. A través de enfoques experimentais baseados no dobre híbrido, leváronse a cabo estudos proteómicos utilizando bibliotecas de ADNc preparadas a partir de tumores de ovario e próstata illados de pacientes. A funcionalidade das interaccións atopadas tamén foi validada por meta-análise bioinformática doutros datos recollidos en bases de datos sobre os seus niveis de expresión e asociación con parámetros de supervivencia clínica. As interaccións seleccionadas tamén foron validadas por co-Inmunoprecipitación e por localización celular mediante microscopía confocal de células cancerosas en cultivo. Algunhas características funcionais das proteínas HMGB1 e HMGB2, así como de NOP53 e MIEN1 - detectadas neste estudo como novas proteínas de interacción física con proteínas HMGB - analizáronse con maior detalle. Analizáronse os efectos producidos polo seu silenciamento e a variación dos niveis de expresión en resposta a tratamentos externos con compostos usados en quimioterapia como carboplatino, paclitaxel, olaparib e bebacizumab. Ademais, as proteínas HMGB1, HMGB2, NOP53 e MIEN1, xunto cos miRNAs miR-155, miR-124 e miR-146a, detectáronse en vesículas extracelulares (EV) derivadas de liñas celulares de próstata e o seu contido nestas moléculas foi alterado. despois do tratamento con temozolomida (TMZ) ou un novo composto híbrido TMZ-ácido valproico (1D). Este estudo é a base para a procura de novos biomarcadores ou dianas terapéuticas útiles para superar a resistencia aos fármacos antitumorais que se utilizan na actualidade nestes tipos de cancros.