title: Genetic alterations of the PIK3CA oncogene in human oral squamous cell carcinoma in an Indian population.
abstract: OBJECTIVE
  The phosphatidylinositol 3-kinase (PIK3) genes, which code for heterodimeric lipid kinases, consist of a catalytic subunit, p110α (PIK3CA), which regulates cell proliferation, apoptosis, and metastasis. Recently, a high frequency of somatic mutations was observed in the PIK3CA gene in various cancer types, including oral squamous cell carcinoma (OSCC). This study aimed to determine the frequency of oncogenic hotspot mutations in exons 9 and 20 of the PIK3CA gene and its correlation with the clinical characteristics of OSCC patients in an Indian population.
  
  
  METHODS
  We analyzed exons 9 and 20 of the PIK3CA gene using polymerase chain reaction (PCR) and direct genomic sequencing of 50 OSCC primary tumors.
  
  
  RESULTS
  We observed two hotspot oncogenic mutations (E542 K, E545 K) in exon 9 and two synonymous mutations (A994 A, T1025 T) in exon 20. Moreover, we identified two single nucleotide polymorphisms (SNPs), rs114587137 (C>T) and rs17849071 (T>G), in intron 9 of the PIK3CA gene. Both oncogenic hotspot mutations were reported primarily in patients with advanced-stage cancer of the buccal mucosa.
  
  
  CONCLUSIONS
  We have observed a 4% oncogenic mutation frequency of the PIK3CA gene, which plays a minor role in the development of OSCC in an Indian population.
authors.affiliation: BRD School of Biosciences, Sardar Patel University, Vallabh Vidhyanagar 388 120, Gujarat, India.
authors.forename: Sejal
authors.initials: S
authors.lastname: Shah
authors.affiliation: Head and Neck Oncosurgeon, ENT Department, P. S. Medical College, Karamsad 388325, Gujarat, India.
authors.forename: Siddharth
authors.initials: S
authors.lastname: Shah
authors.affiliation: BRD School of Biosciences, Sardar Patel University, Vallabh Vidhyanagar 388 120, Gujarat, India.
authors.forename: Harish
authors.initials: H
authors.lastname: Padh
authors.affiliation: BRD School of Biosciences, Sardar Patel University, Vallabh Vidhyanagar 388 120, Gujarat, India. Electronic address: kirankalia@gmail.com.
authors.forename: Kiran
authors.initials: K
authors.lastname: Kalia
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000473:pathology; D058534:Class I Phosphatidylinositol 3-Kinases; D005091:Exons; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000235:genetics* / Q000473:pathology; D009154:Mutation; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D019869:Phosphatidylinositol 3-Kinases; D058534:Class I Phosphatidylinositol 3-Kinases; C484760:PIK3CA protein, human