Departmental Researchers

	Uri Alon focuses on the cell-wide analysis of protein activity, and how cells make decisions and process information. A systems biologist working to develop a “blueprint” of a living cell, he has determined that the biochemical circuitry in the cell is composed of repeating circuit patterns called network motifs, each of which performs a specific information-processing task. Homepage
	Avri Ben-Ze’ev studies the genes and cellular mechanisms involved in cancer. In focusing on beta-catenin, a gene that is abnormally activated in colorectal and many other types of cancer, he has clarified the consequences of beta-catenin hyperactivation in cancerous cells, and identified some of the signals unleashed by this gene in instances of malignancy. Homepage
	Alexander Bershadsky studies how cells move, and the physical forces necessary for cells to attach themselves to the substrate and to one another. In exploring the points of contact, which act as mechanical “sensors” that provide the cell with information about its environment and determine its behavior, he has learned that in cancer cells, the activity of these “sensors” is disrupted, which likely accounts for the cell’s difficulty in adhering to substrates and, consequently, their greater mobility. Life Science Open Day
	Eli Canaani investigates the MLL gene and its protein products, in order to understand their biochemical activities and the mechanism by which they trigger leukemia. Leukemias associated with rearrangement of the MLL gene account for the majority of acute lymphocytic and myelocytic leukemias in infants, and in therapy-related leukemias.
	Benjamin Geiger focuses mainly on the mechanisms responsible for communication between cells, both normal and cancerous. He is attempting to identify and trace the specific molecular involved in intercellular recognition and communication, and to investigate the molecules and signaling processes which mediate such interactions. Homepage, Life Science Open Day
	Zvi Kam is developing and applying high-resolution automated cell-based screening microscopy for functional analysis of cells. Multiple perturbations by compound libraries and by siRNA are applied to reporter cells cultured in multi-well plates, cell images are recorded, and quantitative image analysis scores the responses. This high-throughput platform provides systems biological experimental approach for studying complex cellular mechanisms. Homepage, Life Science Open Day
	Valery Krizhanovsky studies molecular mechanisms of cellular senescence (a permanent cell cycle arrest) and its role in human diseases. His lab utilizes elaborate mouse models and tissue culture techniques to understand how senescent cells communicate with their microenvironment to impact wound healing response, cancer progression and aging. Homepage
	Sima Lev studies the molecular mechanisms of membrane trafficking pathways in mammalian cells. These pathways mediate the transport of proteins, lipids, and sugars to their final cellular destinations and are fundamental to normal cell function and survival. Defects in these pathways are associated with many human diseases and can affect cell cycle progression. She is currently focusing on mechanisms that control the lipid composition of membrane domains along the secretory pathway, as well as the regulation of membrane trafficking events during cell division. Homepage, Life Science Open Day
	Gil Levkowitz utilizes zebrafish embryos as a vertebrate model organism to investigate how coordinated development of multiple neuronal types is achieved in the brain. The lab studies the development and maintenance of dopaminergic neurons and of several neuropeptides- secreting neurons, which reside in the hypothalamus. Understanding these processes is relevant to prospective therapies for neurological disorders as aberrant development of the dopaminergic system might be a major factor contributing to Parkinson’s disease and impairments in hypothalamic neurons are associated with defects in energy balance, and in neuro-endocrine and psychiatric disorders. Homepage, Life Science Open Day
	Moshe Oren is studying the regulation of the p53 tumor suppressor and its relevance to cancer. Specific interests include the analysis of signal transduction pathways that modulate p53 activity in response to various stress signals, exploration of the molecular basis for the ability of p53 to elicit different cell fate changes in response to different triggers, the role of p53 in the interaction between tumor cells and their microenvironment, and (in collaboration with V. Rotter) the analysis of gain of function activities of cancer-associated p53 mutants. In addition, the group is studying the regulation and function of the Mdm2 oncoprotein, a major component of the p53 network. Homepage, Life Science Open Day
	Elior Peles focuses on the biology of Schwann cells and oligodendrocytes, the myelinating glial cells of the peripheral and central nervous system, respectively. His group is studying how these cells recognize and wrap axon with myelin, an insulating lipid membrane that enables the rapid and efficient conduction of nerve impulses. His laboratory is also studying how axon-glia interaction control the molecular organization of the axonal membrane, which is required for the normal function of myelinated nerves and is disturbed in Multiple Sclerosis, as well as in a wide range of other neurological diseases. Homepage
	Varda Rotter focuses on the p53 gene, which as a wild type protein plays a pivotal role in protecting cells from becoming cancerous, but when mutated or inactivated causes the accumulation of genetic instabilities, which in turn induces malignant transformation of cells. On the question of mutant p53 gain of function, which is central in her research, she is collaborating with Moshe Oren and Eytan Domany. As it is well accepted that malignant transformation is a stepwise process involving various defined gene signatures it is the challenge of her studies to discover which of these gene networks involve the p53 protein. Homepage, Life Science Open Day
	Oren Schuldiner studies the molecular mechanism of neuronal remodeling. His lab uses the fruit fly as a model to investigate axon pruning. Using sophisticated genetic and microscopic tools to create and visualize a single mutant neuron in a heterozygous brain, it is possible to study cell autonomous processes that occur late during development in vivo. To understand the mechanisms that regulate axon pruning, his lab focuses finding and characterizing novel proteins that play a role in cell-cell interactions (specifically neuron-glia interactions), cargo trafficking, and signaling within the neurons. His lab also studies the molecular switch that induces re-growth of the axons following pruning. Axon fragmentation during pruning shares molecular similarities with processes occurring in neurodegenerative diseases. Therefore, uncovering the molecular mechanisms underlying pruning and axon re-growth will promote our understanding of axon fragmentation and regeneration during development and disease. Homepage
	Eran Segal develops computational models aimed at understanding how biological processes are regulated at various levels. These include models that integrate transcription factors and DNA sequences, aimed at explaining how complex patterns of gene expression are encoded in DNA sequences and read by cells, and sequence-based models for chromatin structure that explain how nucleosomes get positioned on genomes and how they consequently affect gene expression. Homepage
	Yehiel Zick studies the molecular basis of insulin resistance with a particular emphasis on the role of Ser/Thr kinases as negative-feedback regulators of this process. He also works to understand the activities of galectin-8, one of a family of animal lectins implicated in the development of prostate cancer. Demonstrating that galectin-8 as a modulator of cell cycle progression and as an inducer of cell growth arrest, he is working toward a novel, potentially curative treatment for prostate cancer. Life Science Open Day
	Dov Zipori focuses on the nature of the mesenchyme, primarily on the tendency of this tissue to generate cells in the stem state. Research in this laboratory is divided into three categories. The first is concerned with the molecular basis of stemness. The research team discovered that mesenchymal cells have promiscuous gene expression pattern in that they express genes of various lineage (e.g. T cell receptor components). The functional significance of this unexpected gene expression is a major subject for investigation in the laboratory. The second category relates to the regulation of stem cell self-renewal and differentiation. Previous studies of this research team suggested that the maintenance of the stem state is imposed by differentiation restraining molecules such as transforming growth factor β superfamily members. The group recently showed that Toll-like receptor ligands convey signals that block mesenchymal stem cell (MSC) differentiation. The generality of this phenomenon and its mechanism are now being studied. The third category relates to the practical use of MSC. These cells are used as a therapeutic modality in animal models for human diseases including osteoarthritis and multiple myeloma. Homepage
Professors Emeriti
	Abraham Amsterdam focuses on investigating the control of ovulation and factors, which may explain the risk factors for ovarian cancer. We used ovarian transcriptsomes as a tool for global approach of genes, modulated by gonadotropic hormones in human ovarian granulosa cells. Combined studies by DNA microarrays, biochemical and physiological approaches revealed that epiregulin (Ep) and amphiregulin (Ar), members of the mitogenic epidermal growth factor (EGF), are highly expressed on the level of the genes and the proteins, following gonadotropin stimulation. In contrast, in ovarian cancer, these EGF like factors are expressed constitutively.
	David Givol investigates the tumor suppressor gene p53, the most frequently mutated gene in all cancers, and focuses on mechanisms that activate p53 and the way p53 activates target genes, using microarrays. He also studies the effect of p53 on different chemotherapies. Recently he has been studying connection between stem cells and cancer, exploring the properties of "cancer stem cells" that are responsible for the propagation of malignant tumors. He isolates such stem cells from leukemia and glioblastoma and compares gene expression profiles of stem and non-stem tumor cells and test differential drug response in these cells. Homepage, Life Science Open Day
	Uri Nudel and David Yaffe are investigating the structure, evolution and function of products of the dystrophin gene, which is defective in Duchenne muscular dystrophy (DMD). Gene inactivation techniques were used to study the function of Dp71, the major non-muscle product of the DMD gene, and its possible involvement in development and in learning capacity. Cloning and analysis of the homologous genes from sea urchin and drosophila have important implications with regard to the evolution of the DMD gene family and function of the DMD gene products. These studies showed a very impressive conservation during evolution of the structure of the DMD gene and its multiple products. Functional studies indicated a number of abnormalities associated with mutants of the drosphila orthologue of the DMD gene, including defects in learning capacity. It is interesting to note that in humans, DMD is also often associated with cognitive impairments. Dr. Rachel Sarig, of the same group is also investigating the topic of adult stem cells and their potential application for cell therapy. Recent studies have indicated the prevalence and importance of adult stem cells in development, maintenance and regeneration of various tissues. Muscle progenitor cells are of special interest as an excellent, easy accessible cell type, with well-characterized markers and transcription factors associated with its various differentiation stages, thus offering a convenient model system. The team has isolated, from mouse skeletal muscle a population of slow adherent myogenic cells that can proliferate for extended periods, as suspended clusters of cells (myospheres). Myosphere cells express myogenic markers, and differentiate to muscle fibers both in vitro and in vivo. Cloned populations of these cells and of human myogenic cells are being examined for their plasticity and ability to transdifferentiate into other cell lineages. Preliminary results suggest that these cells can be reprogrammed into neuronal cells. Uri Nudel Life Science Open Day, David Yaffe Life Science Open Day