Abstract 2909: Correlation between the expression of Sox2, Oct4 and deltaNp63 in clinical samples of resected esophageal cancers

Abstract

Abstract Background. DeltaNp63 is the oncogenic isoform in several squamous cell carcinomas including esophageal cancer (EC), however, the mechanisms of regulation of the expression are still unclear. Sox2 and Oct4 are well known transcription factors which function in cancer stemness. We supposed that these two molecules work as transcription factors on deltaNp63, and verified the expression of these genes in cases of resected squamous cell EC. Methods. In 78 surgical specimens of squamous cell EC with no prior neoadjuvant therapy, messenger RNA (mRNA) expression of deltaNp63, Sox2 and Oct4 in EC tissues and corresponding normal tissues was analyzed by quantitative real-time reverse transcription-polymerase chain reaction assay. The mRNA expression was standardized to that of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA. The expressions were compared in terms of clinicopathological factors and prognosis of postoperative survivals. Results. Peason correlation analysis showed significant correlations between expression of deltaNp63 and Sox2 in tumor tissues (r = 0.67, P<0.001), and between deltaNp63 and Oct4 (r = 0.71, P<0.001). The deltaNp63 expressions in tumor tissues were significantly higher than that in corresponding normal tissues (P<0.001), whereas Sox2 and Oct4 did not show significant differences between cancer and non-cancerous tissues. Univariate analysis identified poor differentiation, lymphatic involvement and higher ratio (Tumor/Normal) of expression of Oct4 as significant prognostic factors for poor overall survival, however, lymphatic involvement was the only independent prognostic factor in multivariate analysis (hazard ratio: 5.34; P<0.001). Conclusions. Expression of deltaNp63 in EC tumor tissues showed positive correlation with expression of Sox2 and Oct4. Therefore, these two transcription factors may regulate the expression of deltaNp63. The deltaNp63 is not a strong prognostic factor, however, Oct4 might be a significant predictor for poor prognosis for overall survival in squamous cell EC. Citation Format: Yoshikuni Inokawa, Kenichi Inaoka, Fuminori Sonohara, Hisaharu Oya, Masamichi Hayashi, Yukiko Niwa, Naoki Iwata, Daisuke Kobayashi, Masahiko Koike, Yasuhiro Kodera, Shuji Nomoto. Correlation between the expression of Sox2, Oct4 and deltaNp63 in clinical samples of resected esophageal cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2909.