Delineating The Role Of Arid3b In Normal And Malignant Differentiation Of Esophageal And Cervical Stratified Squamous Epithelia

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL ARID3B is DNA binding protein overexpressed in neuroblastoma and ovarian cancer. We have determined that ARID3B expression is also upregulated during squamous epithelial differentiation (cervix, skin, and esophagus). Therefore, we wanted to assess the role of ARID3B in development of squamous cell carcinomas of the esophagus and cervix. In addition to examining the expression of ARID3B, we also wanted to determine the mechanism for ARID3B regulation in cancer and normal squamous cell epithelia. Recent evidence suggests that p63, specifically the ΔNp63α isoform, transcriptionally regulates Arid3B. p63 is a member of the p53 transcription factor family and is essential for the proliferative potential of stem cells in stratified squamous epithelia. p63 is also involved in various cancers including skin cancer and esophageal cancer. In esophageal squamous cell carcinoma, p63 is ubiquitously expressed and low levels are associated with a poor prognosis. We hypothesize that p63 regulates Arid3B in normal and malignant differentiation of stratified squamous epithelium. To evaluate ARID3B expression in cancer we performed immunohistochemistry on tissue microarrays using two independent Arid3B antibodies. Loss of nuclear Arid3B appears to be common in squamous cell carcinoma of cervix and esophagus. We also examined expression of ARID3B in a normal and a squamous cell carcinoma esophageal cell line. We are also examining the coordinate expression of p63 and Arid3B in serial sections of normal and malignant tissue sections of esophagus, cervix, and skin. We are also investigating the regulation of ARID3B in 3D cell culture models of esophagus differentiation. Our data suggests that misregulation of ARID3B may contribute to the development of cancer in stratified epithelia specifically of the cervix and esophagus. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3038. doi:1538-7445.AM2012-3038