Project description:TAp63 is a transcription factor belonging to the p53 family with important tumor suppressive functions. We show that TAp63-/- mice exhibit an increased susceptibility to UVR-induced cutaneous squamous cell carcinoma (cuSCC). These tumors showed global disruption of miRNA and mRNA expression when compared to tumors arising in wild-type mice. A comparison to similarly sequenced human cuSCC tumors identified miR-30c-2* and miR-497 as being significantly underexpressed in cuSCC. Reintroduction of these miRNAs significantly inhibited the growth of cuSCC cell lines and xenografts. Proteomic profiling of cells transfected with either miRNA showed significant downregulation of proteins related to cell cycle progression and mitosis. A cross-platform comparison of the RNAseq and proteomics signatures identified 7 downregulated proteins, which are also frequently overexpressed in both mouse and human cuSCC. Knockdown of AURKA, KIF18B, PKMYT1, and ORC1 in cuSCC cell lines suppressed tumor cell proliferation and induced cell death. Additionally, we found that an investigational, oral, selective inhibitor of AURKA suppressed cuSCC cell growth and induced cell death, and showed anti-tumor effects in vivo. Our data establishes TAp63 as an essential regulator of miRNA expression during skin carcinogenesis and reveals a novel network of miRNAs and mRNAs, which include potential targets for therapeutic intervention.
Project description:The goal of this study is to compare the differences in the global mRNA expression of WT and TAp63-/- skin and SCC TAp63 is a p53 family member and potent tumor and metastasis suppressor. Here, we show that TAp63-/- mice exhibit an increased susceptibility to UVR- induced cutaneous squamous cell carcinoma (cuSCC). A human-to-mouse comparison of cuSCC tumors identified miR-30c-2* and miR-497 as underexpressed in TAp63-deficient cuSCC. Reintroduction of these microRNAs significantly inhibited the growth of cuSCC cell lines and tumors. Proteomic profiling of cells expressing either microRNA showed downregulation of cell cycle progression and mitosis associated proteins. A mouse to human and cross- platform comparison of RNA-Seq and proteomics data identified a 7-gene signature, including AURKA, KIF18B, PKMYT1, and ORC1, which were overexpressed in cuSCC. Knockdown of these factors in cuSCC cell lines suppressed tumor cell proliferation and induced apoptosis. Additionally, selective inhibition of AURKA suppressed cuSCC cell proliferation, induced apoptosis, and showed anti-tumor effects in vivo. Finally, treatment with miR-30c-2* or miR-497 microRNA mimics was highly effective in suppressing cuSCC growth in vivo. Our data establishes TAp63 as an essential regulator of novel microRNAs that can be therapeutically targeted for potent suppression of cuSCC.
