Neoplastic transformation results in dysfunctional or lack of response to the environmental cues whose integration results in the maintenance of homeostasis in normal cells. Work performed in our laboratories and others have demonstrated that basement membranes possess a complex three-dimensional topography consisting of interwoven fibers pores and elevations in the 20-400 nm size range. Synthetic matrices with features in the biologically relevant nanoscale and sub-micron range have the greatest impact on cell orientation, cell adhesion, migration, proliferation and modulation of intracellular signaling proteins. The overall goal of this proposal is to investigate the impact of nanoscale (< 100 nm) and submicron (100 nm-1um) topographic features, characteristic of basement membranes, on normal, immortalized and transformed (tumorigenic) keratinocyte behavior. Preliminary data suggest that transformed keratinocytes fail to respond or respond only weakly to topographic cues compared to primarily cultured keratinocytes. We have also generated data that suggest intracellular signaling pathways are differentially modulated in transformed vs primary cell cultures. We hypothesize that the altered response of transformed cells to topographic cues may be an essential component in the neoplastic transformation of keratinocytes. We have assembled a strong interdisciplinary team to test the following hypothesis: Totally synthetic surfaces can be engineered through controlled fabrication with biologically relevant feature types, dimensions and distributions that differentially modulate normal, immortalized and carcinogenic keratinocyte behaviors. We will address the following questions: 1.What is the topography of the basement membrane underlying normal keratinocytes and from patients with squamous cell carcinoma (SCC)? 2. What are the effects of nanoscale to microscale topographic features on normal, immortalized and transformed keratinocyte cell behaviors including morphology, orientation, adhesion, migration, proliferation and differentiation? 3.Does topographic cueing differentially modulate intracellular signaling pathways in primary, immortalized non-tumorigenic and transformed tumorigenic keratinocytes? Topographic cues may alter the malignant phenotype or the response to topographic cues may be predictive of metastatic potential and may identify novel molecular targets for therapeutic intervention. ? ? ?