Absence of the frequently reported PIK3CA, CASP8, and NOTCH1 mutations in South Indian oral cancers.
OBJECTIVE
Somatic mutations of the PIK3CA, CASP8, and NOTCH1 have been frequently detected in various human cancers. Our study aimed to analyze the mutational status of these genes in South Indian oral cancers.


METHODS
We performed mutational analysis of the PIK3CA (exons 9 and 20), CASP8 (exon 9), and NOTCH1 (exons 5, 6, 7, 8, and 9) genes in 96, 48, and 44 oral cancer samples, respectively. All the specified exons were PCR (polymerase chain reaction)-amplified and directly sequenced by Sanger sequencing.


RESULTS
PIK3CA gene mutations were not found; however, a synonymous single nucleotide polymorphism (SNP) [rs17849079] was observed frequently [35/96 (36.4%)] in oral cancer samples. Further, no mutations were detected in the CASP8 gene, but observed a frequent [32/48 (66.6%)] SNP [rs1045487] in the oral cancer samples. We did not detect any mutation in the NOTCH1 gene (exons 5, 6, 7, 8, and 9) in all the [0/44] analyzed oral cancer samples.


CONCLUSIONS
This is the first study that reports the status of the PIK3CA, CASP8, and NOTCH1 mutations in South Indian oral cancer samples. Our study suggests that either mutations in these genes are uncommon in South Indian oral cancer samples or likely other genes in this pathway might be mutated.
Department of Genetics, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Chennai, India.
G
G
Arunkumar
Department of Molecular Oncology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
A K
AK
Murugan
Department of Genetics, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Chennai, India.
M
M
Nagarajan
Center for Oncology, Royapettah Government Hospital and Kilpauk Medical College, Chennai, India.
C
C
Ajay
Center for Oncology, Royapettah Government Hospital and Kilpauk Medical College, Chennai, India.
R
R
Rajaraman
Department of Genetics, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Chennai, India.
A K
http://orcid.org/0000-0003-1337-9008
AK
Munirajan
D000328:Adult; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D053181:Caspase 8 / Q000235:genetics*; D058534:Class I Phosphatidylinositol 3-Kinases / Q000235:genetics*; D004252:DNA Mutational Analysis; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000235:genetics*; D009154:Mutation; D051881:Receptor, Notch1 / Q000235:genetics*
C497761:NOTCH1 protein, human; D051881:Receptor, Notch1; D058534:Class I Phosphatidylinositol 3-Kinases; C484760:PIK3CA protein, human; C505530:CASP8 protein, human; D053181:Caspase 8
CASP8; HNSCC; NOTCH1; OSCC; PIK3CA; mutation; oral cancer