ErbB3 AND NUCLEOLAR METABOLISM
The nucleolus is a nuclear domain that is the primary site of transcription of the ribosomal genes (rDNA) by RNA Polymerase I. Rapid growth and division of cells, including tumor ones, is correlated with intensive protein biosynthesis. Different factors that induce cellular stress also often results in ribosome biogenesis impairment that triggers pathways that direct cells to new destinations such as cell cycle arrest, damage repair, differentiation, autophagy, programmed cell death or aging. They are also triggered as a response to oncogenic factor overexpression to protect tissues and organs against extensive proliferation of abnormal cells. Our preliminary results address towards possible link between ErbB3 receptor, a member of EGFR family known to be involved in cell proliferation, with nucleolar function. ErbB3 localizes in the nucleolus but its function in this subnuclear compartment is unknown. This receptor represent an emerging cancer target because it plays an important role in drug resistance therapies: interfere with the function of ErbB3 nucleolar variant could be a new strategy used in cancer therapy.