title: Notch pathway activation is essential for maintenance of stem-like cells in early tongue cancer.
abstract: BACKGROUND
  Notch pathway plays a complex role depending on cellular contexts: promotes stem cell maintenance or induces terminal differentiation in potential cancer-initiating cells; acts as an oncogene in lymphocytes and mammary tissue or plays a growth-suppressive role in leukemia, liver, skin, and head and neck cancer. Here, we present a novel clinical and functional significance of NOTCH1 alterations in early stage tongue squamous cell carcinoma (TSCC).
  
  
  METHODS
  We analyzed the Notch signaling pathway in 68 early stage TSCC primary tumor samples by whole exome and transcriptome sequencing, real-time PCR based copy number, expression, immuno-histochemical, followed by cell based biochemical and functional assays.
  
  
  RESULTS
  We show, unlike TCGA HNSCC data set, NOTCH1 harbors significantly lower frequency of inactivating mutations (4%); is somatically amplified; and, overexpressed in 31% and 37% of early stage TSCC patients, respectively. HNSCC cell lines over expressing NOTCH1, when plated in the absence of attachment, are enriched in stem cell markers and form spheroids. Furthermore, we show that inhibition of NOTCH activation by gamma secretase inhibitor or shRNA mediated knockdown of NOTCH1 inhibits spheroid forming capacity, transformation, survival and migration of the HNSCC cells suggesting an oncogenic role of NOTCH1 in TSCC. Clinically, Notch pathway activation is higher in tumors of non-smokers compared to smokers (50% Vs 18%, respectively, P=0.026) and is also associated with greater nodal positivity compared to its non-activation (93% Vs 64%, respectively, P=0.029).
  
  
  CONCLUSIONS
  We anticipate that these results could form the basis for therapeutic targeting of NOTCH1 in tongue cancer.
authors.affiliation: Integrated Genomics Laboratory, Advanced Centre for Treatment, Research and Education In Cancer, Tata Memorial Centre, Navi Mumbai- 410210, India.
authors.forename: Pawan
authors.initials: P
authors.lastname: Upadhyay
authors.affiliation: Division of Head and Neck Oncology, Department of Surgical Oncology, Tata Memorial Hospital, Tata Memorial Centre, Mumbai- 4100012, India.
authors.forename: Sudhir
authors.initials: S
authors.lastname: Nair
authors.affiliation: Shilpee Laboratory, Advanced Centre for Treatment, Research and Education In Cancer, Tata Memorial Centre, Navi Mumbai- 410210, India.
authors.forename: Ekjot
authors.initials: E
authors.lastname: Kaur
authors.affiliation: Integrated Genomics Laboratory, Advanced Centre for Treatment, Research and Education In Cancer, Tata Memorial Centre, Navi Mumbai- 410210, India.
authors.forename: Jyotirmoi
authors.initials: J
authors.lastname: Aich
authors.affiliation: Integrated Genomics Laboratory, Advanced Centre for Treatment, Research and Education In Cancer, Tata Memorial Centre, Navi Mumbai- 410210, India.
authors.forename: Prachi
authors.initials: P
authors.lastname: Dani
authors.affiliation: Integrated Genomics Laboratory, Advanced Centre for Treatment, Research and Education In Cancer, Tata Memorial Centre, Navi Mumbai- 410210, India.
authors.forename: Vidyalakshmi
authors.initials: V
authors.lastname: Sethunath
authors.affiliation: Integrated Genomics Laboratory, Advanced Centre for Treatment, Research and Education In Cancer, Tata Memorial Centre, Navi Mumbai- 410210, India.
authors.forename: Nilesh
authors.initials: N
authors.lastname: Gardi
authors.affiliation: Integrated Genomics Laboratory, Advanced Centre for Treatment, Research and Education In Cancer, Tata Memorial Centre, Navi Mumbai- 410210, India.
authors.forename: Pratik
authors.initials: P
authors.lastname: Chandrani
authors.affiliation: Integrated Genomics Laboratory, Advanced Centre for Treatment, Research and Education In Cancer, Tata Memorial Centre, Navi Mumbai- 410210, India.
authors.forename: Mukul
authors.initials: M
authors.lastname: Godbole
authors.affiliation: Division of Head and Neck Oncology, Department of Surgical Oncology, Tata Memorial Hospital, Tata Memorial Centre, Mumbai- 4100012, India.
authors.forename: Kavita
authors.initials: K
authors.lastname: Sonawane
authors.affiliation: Integrated Genomics Laboratory, Advanced Centre for Treatment, Research and Education In Cancer, Tata Memorial Centre, Navi Mumbai- 410210, India.
authors.forename: Ratnam
authors.initials: R
authors.lastname: Prasad
authors.affiliation: Advanced Centre for Treatment, Research and Education In Cancer, Tata Memorial Centre, Navi Mumbai- 410210, India.
authors.forename: Sadhana
authors.initials: S
authors.lastname: Kannan
authors.affiliation: Department of Pathology, Advanced Centre for Treatment, Research and Education In Cancer, Tata Memorial Centre, Navi Mumbai- 410210, India.
authors.forename: Beamon
authors.initials: B
authors.lastname: Agarwal
authors.affiliation: Department of Pathology, Tata Memorial Hospital, Tata Memorial Centre, Mumbai- 400012, India.
authors.forename: Shubhada
authors.initials: S
authors.lastname: Kane
authors.affiliation: Department of Medical Oncology, Advanced Centre for Treatment, Research and Education In Cancer, Tata Memorial Centre, Mumbai- 400012, India.
authors.forename: Sudeep
authors.initials: S
authors.lastname: Gupta
authors.affiliation: Shilpee Laboratory, Advanced Centre for Treatment, Research and Education In Cancer, Tata Memorial Centre, Navi Mumbai- 410210, India.
authors.forename: Shilpee
authors.initials: S
authors.lastname: Dutt
authors.affiliation: Integrated Genomics Laboratory, Advanced Centre for Treatment, Research and Education In Cancer, Tata Memorial Centre, Navi Mumbai- 410210, India.
authors.forename: Amit
authors.initials: A
authors.lastname: Dutt
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D002470:Cell Survival; D059472:Exome; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D014411:Neoplastic Stem Cells / Q000166:cytology* / Q000473:pathology; D051881:Receptor, Notch1 / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics; D012907:Smoking / Q000009:adverse effects; D018874:Spheroids, Cellular / Q000378:metabolism; D014062:Tongue Neoplasms / Q000235:genetics / Q000378:metabolism*; D059467:Transcriptome; D055815:Young Adult
chemical_list: C497761:NOTCH1 protein, human; D051881:Receptor, Notch1
keywords: IHC based expression analysis; Notch pathway inhibitors; cancer stem cell-like feature; early stage tongue cancer; exome and transcriptome sequencing