Polymorphism in Cyclin D1 gene (G870A) and the risk of squamous cell carcinoma of the larynx

Background: Nowadays, intensive studies focus on the identification of early cancer transforming events. This may help in providing genetic markers for early cancer detection, thus predicting patient prognosis and establishing treatment strategies. Among several of the chromosomal regions and gene assemblies implicated in HNSCC tumor genesis, the arrangement of the 11q13 band particularly leading to cyclin D1gene CCND1 amplification is the most frequently genetic alteration observed. Amplification of the CCND1 gene occurs in16–38% of HNSCC, which results in cyclin D1over expression, and it has been shown to correlate with poor prognosis, reduced disease-free interval, recurrence and lymph node metastases. A common adenine-to-guanine substitution polymorphism (A870G) in the CCND1gene at codon 242 affects splicing of the CCND1 transcript, resulting in an altered messenger RNA transcript and a longer-life protein which may cause uncontrollable cellular growth.
Aim of the work: This study was conducted to investigate the correlation between (CCND1) polymorphism and cancer larynx. Also, we studied the frequencies of CCND1 genotypes in cancer larynx patient and its relationship with the incidence of cancer, sex, age, site of lesion, tumor extension, and lymph node affection.
 Patient and method:  The genotyping study was done using the PCR-RFLP method in 31 patients with cancer larynx and 31 healthy controls. Cancer tissue and blood sampling was taken for DNA polymorphism from patient group, but control group were subjected only to collection of blood sample for genetic study for DNA polymorphism.
Result: Among the studied 31 patients with cancer larynx the genotype of the blood and tissue sample GG was found in 26 patients (83.9%) while the AA genotype was found in 5 patients (16.1%). The CCND1 genotyping in the control group was AA genotype in 2 patients (6.5%) and was GG genotype in 29 patients (93.5%). There were no association between the patients’ genotypes and   incidence of cancer larynx, sex or smoking. 
Conclusion: In this work the relation of CCDN1 A870G polymorphism and the risk of cancer larynx were studied. No statistically significant difference was found between cancer and control groups as regard to genotype and allele distribution.