Epithelial malignancies represent the vast majority of human cancers. Understanding the development and progression of these cancers is essential in the effort to identify new therapeutic targets. Squamous cell carcinoma (SCC) is the second most common skin cancer, with outcomes that are often inversely correlated with differentiation state. To identify long non-coding RNA (lncRNA) regulators of both epidermal differentiation and neoplasia, we performed RNA-Sequencing and identified the novel, putative lncRNA SMRT-2. SMRT-2 is down-regulated in all 12 tumor samples tested compared to normal patient and site matched controls. SMRT-2 is also up-regulated over the course of epidermal differentiation and preliminary data indicates it is required for this process. First, we will generate and characterie organotypic human epidermal neoplasia with altered SMRT-2 expression. The model we will use closely resembles human SCC and is amenable to genetic manipulation [9]. We have designed experiments to both deplete SMRT-2 and force SMRT-2 expression in the context of this model. These experiments will allow us to assess the ability of SMRT-2 to promote tumorigenesis and diminish neoplastic differentiation, as well as evaluate its potential role as a tumor suppressor in inhibiting neoplastic invasion and cell proliferation. Overall, these studies will allow us to identify the specific role of SMRT-2 in epidermal neoplasia. LncRNA functional mechanisms have previously been elucidated by looking to interaction partners [14]. To further characterize the mechanism of SMRT-2, we will next characterize the SMRT-2 interactome by identifying its protein, RNA, and DNA interaction partners. Protein interaction partners will be identified by using a protein microarray chip to which labeled SMRT-2 will be hybridized [32]. RNA and DNA interaction partners will be identified by RNA pulldown of SMRT-2 and interacting transcripts [16] or genomic DNA [33] will be subsequently sequenced. These studies will be conducted in the context of both epidermal differentiation and organotypic epidermal neoplasia to allow identification of SMRT-2 interactions that might be deranged in cancer. Additionally, knowing the SMRT-2 interactome will allow us to understand the mechanism of SMRT-2 action in the context of cellular biomolecules. With this knowledge, either SMRT-2 or one of its interaction partners could be used as a biomarker or therapeutic target of epidermal neoplasia. At the end of the proposed funding period, we hope to have characterized the role of SMRT-2 in epidermal tumor progression and identified a potential mechanism of action via its interaction partners. These results may illuminate additional therapeutic targets for the treatment of SCC and other epithelial cancers.
This proposal aims to characterize how a novel non-coding RNA transcript mediates cancer progression. The ultimate goal is to identify potential novel targets for the prevention and treatment of human cancers.
| Bhaduri, Aparna; Ungewickell, Alexander; Boxer, Lisa D et al. (2015) Network Analysis Identifies Mitochondrial Regulation of Epidermal Differentiation by MPZL3 and FDXR. Dev Cell 35:444-57 |
