Daniel Rubio

Publications (6)24.89 Total impact

• Article: Human mesenchymal stem cell transformation is associated with a mesenchymal-epithelial transition.

  Daniel Rubio, Silvia Garcia, Teresa De la Cueva, Ma F Paz, Alison C Lloyd, Antonio Bernad, Javier Garcia-Castro
  [show abstract] [hide abstract]
  ABSTRACT: Carcinomas are widely thought to derive from epithelial cells with malignant progression often associated with an epithelial-mesenchymal transition (EMT). We have characterized tumors generated by spontaneously transformed human mesenchymal cells (TMC) previously obtained in our laboratory. Immunohistopathological analyses identified these tumors as poorly differentiated carcinomas, suggesting that a mesenchymal-epithelial transition (MET) was involved in the generation of TMC. This was corroborated by microarray and protein expression analysis that showed that almost all mesenchymal-related genes were severely repressed in these TMC. Interestingly, TMC also expressed embryonic antigens and were able to integrate into developing blastocysts with no signs of tumor formation, suggesting a dedifferentiation process was associated with the mesenchymal stem cell (MSC) transformation. These findings support the hypothesis that some carcinomas are derived from mesenchymal rather than from epithelial precursors.
  Experimental Cell Research 03/2008; 314(4):691-8. · 3.58 Impact Factor
• Source

  Available from: Javier García-Castro

  Article: Molecular characterization of spontaneous mesenchymal stem cell transformation.

  Daniel Rubio, Silvia Garcia, Maria F Paz, Teresa De la Cueva, Luis A Lopez-Fernandez, Alison C Lloyd, Javier Garcia-Castro, Antonio Bernad
  [show abstract] [hide abstract]
  ABSTRACT: We previously reported the in vitro spontaneous transformation of human mesenchymal stem cells (MSC) generating a population with tumorigenic potential, that we termed transformed mesenchymal cells (TMC). Here we have characterized the molecular changes associated with TMC generation. Using microarrays techniques we identified a set of altered pathways and a greater number of downregulated than upregulated genes during MSC transformation, in part due to the expression of many untranslated RNAs in MSC. Microarray results were validated by qRT-PCR and protein detection. In our model, the transformation process takes place through two sequential steps; first MSC bypass senescence by upregulating c-myc and repressing p16 levels. The cells then bypass cell crisis with acquisition of telomerase activity, Ink4a/Arf locus deletion and Rb hyperphosphorylation. Other transformation-associated changes include modulation of mitochondrial metabolism, DNA damage-repair proteins and cell cycle regulators. In this work we have characterized the molecular mechanisms implicated in TMC generation and we propose a two-stage model by which a human MSC becomes a tumor cell.
  PLoS ONE 02/2008; 3(1):e1398. · 4.09 Impact Factor
• Source

  Available from: Teresa de la Cueva

  Article: Refinement of intrathymic injection in mice.

  Teresa de la Cueva, Angel Naranjo, Ernesto de la Cueva, Daniel Rubio
  [show abstract] [hide abstract]
  ABSTRACT: Direct intrathymic injection is a common procedure used in several types of experimental protocols in the mouse. Currently available approaches involve major surgical procedures that expose the thoracic cavity, resulting in an increased risk of poor recovery and postsurgical complications. The authors sought to refine this surgery to reduce animal pain and distress without compromising overall efficiency of the technique. Using a minimally invasive method that does not expose the thoracic cavity, the authors gave accurately placed intrathymic injections, as confirmed by analyses with a reporter dye. They describe this new approach for intrathymic injection in mice that reduces complications associated with lengthy periods of anesthesia and thoracic cavity exposure.
  Lab Animal 06/2007; 36(5):27-32. · 0.38 Impact Factor
• Article: Spontaneous human adult stem cell transformation.

  Daniel Rubio, Javier Garcia-Castro, María C Martín, Ricardo de la Fuente, Juan C Cigudosa, Alison C Lloyd, Antonio Bernad
  [show abstract] [hide abstract]
  ABSTRACT: Human adult stem cells are being evaluated widely for various therapeutic approaches. Several recent clinical trials have reported their safety, showing them to be highly resistant to transformation. The clear similarities between stem cell and cancer stem cell genetic programs are nonetheless the basis of a recent proposal that some cancer stem cells could derive from human adult stem cells. Here we show that although they can be managed safely during the standard ex vivo expansion period (6-8 weeks), human mesenchymal stem cells can undergo spontaneous transformation following long-term in vitro culture (4-5 months). This is the first report of spontaneous transformation of human adult stem cells, supporting the hypothesis of cancer stem cell origin. Our findings indicate the importance of biosafety studies of mesenchymal stem cell biology to efficiently exploit their full clinical therapeutic potential.
  Cancer Research 05/2005; 65(8):3035-9. · 7.86 Impact Factor
• Article: Dedifferentiated adult articular chondrocytes: a population of human multipotent primitive cells.

  Ricardo de la Fuente, José Luis Abad, Javier García-Castro, Gemma Fernández-Miguel, Jordi Petriz, Daniel Rubio, Carlos Vicario-Abejón, Pedro Guillén, Manuel A González, Antonio Bernad
  [show abstract] [hide abstract]
  ABSTRACT: To test the hypothesis that dedifferentiated adult human cartilage chondrocytes (HAC) are a true multipotent primitive population. Studies to characterize dedifferentiated HAC included cell cycle and quiescence analysis, cell fusion, flow-FISH telomere length assays, and ABC transporter analysis. Dedifferentiated HAC were characterized by flow cytometry, in parallel with bone marrow mesenchymal stem cells (MSC) and processed lipoaspirate (PLA) cells. The in vitro differentiation potential of dedifferentiated HAC was studied by cell culture under several inducing conditions, in multiclonal and clonal cell populations. Long-term HAC cultures were chromosomically stable and maintained cell cycle dynamics while showing telomere shortening. The phenotype of dedifferentiated HAC was quite similar to that of human bone marrow MSC. In addition, this population expressed human embryonic stem cell markers. Multiclonal populations of dedifferentiated HAC differentiated to chondrogenic, osteogenic, adipogenic, myogenic, and neurogenic lineages. Following VEGF induction, dedifferentiated HAC expressed characteristics of endothelial cells, including AcLDL uptake. A total of 53 clonal populations of dedifferentiated HAC were efficiently expanded; 17 were able to differentiate to chondrogenic, osteogenic, and adipogenic lineages. No correlation was observed between telomere length or quiescent population and differentiation potential in the clones assayed. Dedifferentiated HAC should be considered a human multipotent primitive population.
  Experimental Cell Research 08/2004; 297(2):313-28. · 3.58 Impact Factor
• Article: Polyprotein processing protease of African swine fever virus: purification and biochemical characterization.

  Daniel Rubio, Alí Alejo, Irene Rodríguez, María L Salas
  [show abstract] [hide abstract]
  ABSTRACT: The purified recombinant African swine fever virus polyprotein processing protease cleaves the two GG-X sites in polyprotein pp62 with the same efficiency. Cleavage at the site that is first recognized in vivo is not a requisite for cleavage at the second site, suggesting the existence of mechanisms that control the ordered processing of the polyprotein during infection.
  Journal of Virology 05/2003; 77(7):4444-8. · 5.40 Impact Factor