Association of Two BRM Promoter Polymorphisms with Head and Neck Squamous Cell Carcinoma Risk
Menée sur des lignées cellulaires, des échantillons prélevés sur 668 patients atteints d'un carcinome épidermoïde de la tête et du cou et sur 700 témoins, cette étude identifie des polymorphismes d'un promoteur du gène BRM en association avec un risque accru de la maladie
The SWI/SNF chromatin remodeling complex is an important regulator of gene expression that has been linked to cancer development. Expression of Brahma (BRM), a critical catalytic subunit of SWI/SNF, is lost in a variety of solid tumors. Two novel BRM promoter polymorphisms (BRM -741 and BRM -1321) have been correlated with BRM loss and elevated cancer risk. The aim(s) of this study were to examine BRM expression in head and neck squamous cell carcinoma (HNSCC) and to correlate BRM polymorphisms with HNSCC risk. BRM expression studies were performed on 8 HNSCC cell lines and 76 surgically resected tumor samples. A case-control study was conducted on 668 HNSCC patients (oral cavity, oropharynx, larynx, and hypopharynx) and 700 healthy matched controls. BRM expression was lost in 25% of cell lines and 16% of tumors. The homozygous genotype of each polymorphism was significantly associated with increased HNSCC risk (BRM -741: aOR 1.75, 95% CI 1.2-2.3, p<0.001; BRM -1321: aOR 1.65, 95% CI 1.2-2.2, p<0.001). Individuals that were homozygous for both BRM polymorphisms had a more than 2-fold increase in the risk of HNSCC (aOR 2.23, 95% CI 1.5-3.4, p<0.001). A particularly elevated risk was seen within the oropharynx, HPV+ sub-group for carriers of both homozygous variants (aOR 3.09, 95% CI 1.5-6.8, p=0.004). BRM promoter polymorphisms appear to act as susceptibility markers of HNSCC with potential utility in screening, prevention, and treatment.
http://carcin.oxfordjournals.org/content/early/2013/01/14/carcin.bgt008.abstract