Abstract 4811: Pro-oncogenic role of NOTCH1 in early tongue squamous cell carcinoma

Abstract

Abstract Notch pathway play a context-dependent tumor-suppressive or pro-oncogenic role in solid tumors and hematological malignancies. In head and neck cancer, inactivating mutations in NOTCH1 are associated with poor prognosis. Here we perform meta-analysis of DNA copy number and gene expression profiling of NOTCH signaling pathway genes in 35 paired primary T1 and T2 stage tongue tumors, comprising of Notch ligands, receptors and target genes. We find 32% of primary tongue squamous cell carcinoma (TSCC) tumors amplify NOTCH signaling pathway components; and over express activated NOTCH1based on immuno-histochemical staining in an additional series of 50 surgically resected paired TSCC tumors. Interestingly, these alterations: amplification at Notch ligand DLL3 (χ2 = 7.575, P = 0.023); over expression of Notch pathway target gene HEY2 transcript (χ2 = 9.885, P = 0.007); and expression of activated NOTCH1 (χ2 = 7.575, P = 0.023) positively correlate with N+ve and non- smoking status of patients. In a parallel effort, we characterized four HNSCC cell lines– NT8E, OT9, AW13516, and AW8507– established from Indian patients using whole exome, whole transcriptome sequencing and SNP array assays. Significant amplification and over expression of NOTCH signaling pathway components were observed in AW13516 and NT8E cells. Inhibition of NOTCH activation by gamma secretase inhibitor or shRNA mediated knockdown of NOTCH1 could inhibit transformation, survival, migration and invasion of NT8E cells. Taken together, we present that activation of Notch signaling pathway in a subset of TSCC patients is associated with nodal positivity and non-smoking status among early tongue cancer patients. Citation Format: Pawan Upadhyay, Jyotirmoi Aich, Vidyalakshmi Sethunath, Prachi Dani, Sadhana Kannan, Pratik Chandrani, Kavitha Sonawane, Beamon Agarwal, Shubhada Kane, Sudhir Nair, Amit Dutt. Pro-oncogenic role of NOTCH1 in early tongue squamous cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4811. doi:10.1158/1538-7445.AM2015-4811