CAT ENG CAS FRA  
RESEARCH
The overall aim of our research is to understand how form develops in the embryo, how it is maintained and remodeled in the adult and how it is deregulated in disease.
STEM CELLS AND CANCER STEM CELLS


Ruiz i Altaba Lab

The biology of stem cells is the major focus of the laboratory, both in normal development and in disease. The brain and other organs harbor adult tissue-specific stem cells that are involved in tissue maintenance and in repair following injury and during aging. We support a simple definition of stem cells as those cells that can self-renew and can give rise to one or more kinds of more specialized cells. For instance, neural stem cells can give rise to neurons, astrocytes and oligodendrocytes in the brain and those at the bottom of the crypts of Lieberkühn to the entire epithelial lining of the intestine.

Our main effort is to elucidate the mechanisms that control self-renewal and impart stemness to particular cells at a given time under a given set of circumstances. Stemness is, in our view, a property, and we need to follow it functionally in order to inquire about its consequences on cell behavior and fate. Our efforts have been mostly focused on neural stem cells of the subventricular zone of the lateral ventricle of the forebrain. In addition, we have addressed and maintain an interest in other adult stem cells, such as those of the intestine, and on embryonic stem cells. Moreover, trying to understand stemness includes an understanding of how adult differentiated cells can be reprogrammed to acquire embryonic stem cell-like properties.

Additional work addresses the biology of stem cells in cancer, focusing on glioblastoma, melanoma, colon cancer and others. These are cells in the tumor that display stemness properties and self-renew. In addition, these cells have the capacity to induce a new tumor, raising the possibility that they are responsible for tumor recurrence and metastases. While much effort has been devoted to and some success exists in fighting cancer, there is little one can offer today to effectively treat metastases.

We subscribe to the idea that an understanding of stem cell behavior in normal development, homeostasis, and cancer can shed light on the biology of stemness and yield new therapeutic avenues. A major effort of the lab thus focuses on understanding how cancer stem cells self-renew, sustain and perpetuate the growing tumor mass on the one hand, and on the other how they may seed new metastases in distant organs.

One major axis of investigation in our laboratory concerns the function and logic of the HEDGEHOG (HH) – GLI pathway. This is an intercellular signaling pathway with which cells communicate to know or ascertain their position, fate and/or behavior. Over the last decade we have pioneered the function of the GLI transcription factors in vertebrate cells and human tumors, developing concepts like the GLI code and its integration of HH and non-HH signals. We have also proposed a model for tumor progression based on the morphogenetic action of GLI1 and increases in its function by oncogenic and loss of tumor suppressive events. Consequently, various lines of research in the lab track the interactions of HH-GLI and the GLI code with other important signaling pathways and oncogenic events such as loss of p53, RAS-MEK/AKT signaling, and activation of the BMP and WNT pathways.

One long-term goal is to develop a conceptual framework to understand the myriad of events involved in development and cancer. Furthermore, we are involved in developing small molecule inhibitors to these and other targets for chemical genetics and a possible therapeutic outlook.