Project Summary/Abstract Background: Cancer originates from genetic alterations that lead to changes in gene expression programs that promote tumor survival, growth, motility and inhibits differentiation and apoptosis. The mRNAs from this oncogenic gene expression program must be exported to the cytoplasm to be translated into protein in order to promote tumorigenesis. Whether there is regulation of export of tumor specific mRNAs and the potential proteins involved in this process is unknown. We have shown that tumor specific NXF1 adaptor proteins regulate export of oncogenic mRNAs. The adaptor proteins are also highly upregulated during tumor initiation and knockdown of specific adaptors inhibit tumorigenesis. Objective/hypothesis: This proposal seeks to understand the molecular mechanisms driving the progression from normal to neoplastic skin using a RAS driven human epidermal tumor model. Our preliminary data suggests that 4 adaptor proteins are highly upregulated during tumor initiation that associates with NXF1 to mediate the export of the oncogenic gene expression program. Our objective is to characterize the role of each tumor induced NXF1 adaptor protein in the progression of normal to neoplastic skin. Furthermore we seek to determine the specific transcripts that each adaptor protein binds during tumor initiation to promote tumorigenesis. Specific Aims: (1) To determine the role of NXF1 adaptor proteins in the progression from normal to neoplastic skin and (2) to identify the transcripts associated with NXF1 adaptor proteins and determine which bound transcripts are exported. Study Design: To study epidermal tumorigenesis in a more clinically relevant setting, we generate 3-dimensionally intact human skin, containing human epidermal cells (that have been permanently knocked down for adaptor proteins) in the context of human dermal stroma and basement membrane, regenerated on immune compromised mice. By using this model, we can perform loss of function experiments on NXF1 adaptor proteins in regenerated human skin to characterize their role in epidermal growth, differentiation, and progression to neoplasia. We will use CLIP-Seq to determine the RNAs associated with each adaptor protein during the progression from normal to neoplastic epidermis.

Project Narrative Dysregulation in gene expression programs can lead to cancer including squamous cell carcinomas which is the 2nd most diagnosed cancer in the U.S. This proposal seeks to understand the underlying molecular mechanisms that govern the progression of normal human skin to neoplasia. The efforts of this proposal will define the role of the mRNA export pathway in tumor initiation, which may yield insights into the development of therapies for epidermal disorders.